BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identifica...BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.展开更多
In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate ...In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.展开更多
The current research aims to assess the staff and patients’ effective doses during Nuclear medicine (NM) bone scans procedures. The administered activity was utilized to quantify the patients’ effective doses, while...The current research aims to assess the staff and patients’ effective doses during Nuclear medicine (NM) bone scans procedures. The administered activity was utilized to quantify the patients’ effective doses, while personnel’s effective doses were quantified using thermoluminescent detectors (TLD-100). The average administered activity was 650 (440 to 1440) MBq procedures using SPECT gamma camera system. The average annual staff effective dose (mSv) was estimated to be 2.3 (0.1 to 4.9). The typical patient’s effective dose was 4.9 (3.6 to 6.0) mSv per procedure. Staff exposure within the yearly effective dose limits. Patients’ exposure optimization is required based on patient weight. Estimating staff eye lens doses is suggested to confirm that the yearly effective radiation doses are within the safety range.展开更多
Acute abdominal pain is a medical emergency that is characterized by abrupt, acute, recently developed abdominal pain that is accompanied by other signs that are confined in the abdomen area. The purpose of this study...Acute abdominal pain is a medical emergency that is characterized by abrupt, acute, recently developed abdominal pain that is accompanied by other signs that are confined in the abdomen area. The purpose of this study was to illustrate how ultrasonography may be used to identify sudden abdominal pain. From December 2021 and March 2022, a comprehensive examination of 50 patients with acute abdominal pain was conducted. Seven hospitals in Khartoum State, Sudan, examined individuals with clinically suspected abdominal and pelvic deformities using 3.5 MHz ultrasound machines. Out of the 50 (100%) patients who were presented with acute abdominal pain 10 (20%) were appendicitis, 9 (18%) were cholecystitis, 8 (16%) were Nephrolithiasis, 3 (6%) were Choledocholithiasis, 3 (6%) were Chronic kidney disease, 3 (6%) were Cholelithiasis, 3 (6%) were Cystitis, 4 (8%) were Ascites, 1 (2%) was acute kidney injury, 1 (2%) was Acute Peritonitis, 1 (2%) was Diverticulum and 1 (2%) each was of Epigastric hernia, Hepatosplenomegaly, Liver cirrhosis, Nephritis and Ovarian cysts respectively. According to the study results, ultrasonography (US) proceeds to be the go-to imaging strategy in most situations, particularly for younger and female patients, where limiting exposure to radiation must be obligated. The application of Computerized Tomography CT should be restricted in circumstances where there is no diagnostic US and, in all situations, where there is a significant disparity between medical symptoms and negative imaging in the US.展开更多
Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) a...Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer.Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared.Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS.Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.展开更多
Pulmonary nodules are small, round, or oval-shaped growths on the lungs. They can be benign (noncancerous) or malignant (cancerous). The size of a nodule can range from a few millimeters to a few centimeters in diamet...Pulmonary nodules are small, round, or oval-shaped growths on the lungs. They can be benign (noncancerous) or malignant (cancerous). The size of a nodule can range from a few millimeters to a few centimeters in diameter. Nodules may be found during a chest X-ray or other imaging test for an unrelated health problem. In the proposed methodology pulmonary nodules can be classified into three stages. Firstly, a 2D histogram thresholding technique is used to identify volume segmentation. An ant colony optimization algorithm is used to determine the optimal threshold value. Secondly, geometrical features such as lines, arcs, extended arcs, and ellipses are used to detect oval shapes. Thirdly, Histogram Oriented Surface Normal Vector (HOSNV) feature descriptors can be used to identify nodules of different sizes and shapes by using a scaled and rotation-invariant texture description. Smart nodule classification was performed with the XGBoost classifier. The results are tested and validated using the Lung Image Consortium Database (LICD). The proposed method has a sensitivity of 98.49% for nodules sized 3–30 mm.展开更多
AIM To establish a threshold value for liver fat content between healthy children and those with nonalcoholic fatty liver disease(NAFLD) by using magnetic resonance imaging(MRI), with liver biopsy serving as a referen...AIM To establish a threshold value for liver fat content between healthy children and those with nonalcoholic fatty liver disease(NAFLD) by using magnetic resonance imaging(MRI), with liver biopsy serving as a reference standard. METHODS The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel pointresolved 1H MR-Spectroscopy(1H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cutoff value. Lin coefficient test was used to evaluate thecorrelation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables. RESULTS According to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF.CONCLUSION MRS is an accurate and precise method for detecting NAFLD in children.展开更多
In this study, to explore the radiation protection effects of Lyophyllum Decastes Sing (LDS), a hot distilled-water extract of LDS was orally administered at a dosage of 250mg/kg every other day for a period of 2 we...In this study, to explore the radiation protection effects of Lyophyllum Decastes Sing (LDS), a hot distilled-water extract of LDS was orally administered at a dosage of 250mg/kg every other day for a period of 2 weeks in irradiated mice. An automatic blood cell counter was used to measure white blood cells (lymphocytes, monocyte, and granulocytes) one day before X-ray irradiation, and 3 hours, 12 hours, 24 hours, 3 days, 7 days, 15 days and 30 days after irradiation. The Dunnett test was used to examine statistical significance of differences. The peripheral blood cell counts in the Lyophyllum-administered non-irradiation group revealed an increase in the numbers of ieukocytes, lymphocytes and monocytes. For 2 Gy whole body radiation, a significant statistical difference was found between the X-ray group and the Lyophyllum plus X-ray group in the numbers of leukocytes, lymphocytes and monocytes. The results suggest that Lyophyllum restrains blood cell-count falling after irradiation, which is probably mediated at least in part by hemopoietic function, and NK and LAK activities seems to play a role in preventing secondary irffections associated with irradiation.展开更多
AIM: To analyze contrast-enhanced ultrasound(CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma(HEHE) in comparison to other multilocular benign focal liver lesions(FLL).METHODS: Twenty-f...AIM: To analyze contrast-enhanced ultrasound(CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma(HEHE) in comparison to other multilocular benign focal liver lesions(FLL).METHODS: Twenty-five patients with histologically proven HEHE and 45 patients with histologically proven multilocular benign FLL were retrospectively reviewed. Four radiologists assessed the CEUS enhancement pattern in consensus.RESULTS: HEHE manifested as a single(n = 3) or multinodular(n = 22) FLL. On CEUS, HEHE showed rim-like(18/25, 72%) or heterogeneous hyperenhancement(7/25, 28%) in the arterial phase and hypoenhancement(25/25, 100%) in the portal venous and late phases(PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas(18/25, 72%); in seven patients(7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal nodular hyperplasia showed hyperenhancement as the most distinctive feature(P < 0.01).CONCLUSION: CEUS allows for characterization of unequivocal FLL. By analyzing the hypoenhancement in the PVLP, CEUS can determine the malignant nature of HEHE.展开更多
Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening...Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy.The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and colonoscopy.However,despite the fact that CTC has been officially endorsed for CRC screening of average-risk individuals by different scientif ic societies including the American Cancer Society,the American College of Radiology,and the US Multisociety Task Force on Colorectal Cancer,other entities,such as the US Preventive Services Task Force,have considered the evidence insuff icient to justify its use as a mass screening method.Medicare has also recently denied reimbursement for CTC as a screening test.Nevertheless,multiple advantages exist for using CTC as a CRC screening test:high accuracy,full evaluation of the colon in virtually all patients,non-invasiveness,safety,patient comfort,detection of extracolonic findings and cost-effectiveness.The main potential drawback of a CTC screening is the exposure to ionizing radiation.However,this is not a major issue,since low-dose protocols are now routinely implemented,delivering a dose comparable or slightly superior to the annual radiation exposure of any individual.Indirect evidence exists that such a radiation exposure does not induce additional cancers.展开更多
A male patient underwent conventional transcatheter chemoembolization for advanced recurrent hepatocellular carcinoma(HCC). Even after the injection of 7 m L of lipiodol followed by gelatin sponge particles, the flow ...A male patient underwent conventional transcatheter chemoembolization for advanced recurrent hepatocellular carcinoma(HCC). Even after the injection of 7 m L of lipiodol followed by gelatin sponge particles, the flow of feeding arteries did not slow down. A repeat angiography revealed a newly developed vascular lake draining into systemic veins; however, embolization was continued without taking noticing of the vascular lake. The patient's level of consciousness deteriorated immediately after the procedure, and non-contrast computed tomography revealed pulmonary and cerebral lipiodol embolisms. The patient's level of consciousness gradually improved after 8 wk in intensive care. In this case, a vascular lake emerged during chemoembolization and drained into systemic veins, offering a pathway carrying lipiodol to pulmonary vessels, the most likely cause of this serious complication. We should be aware that vascular lakes in HCC may drain into systemic veins and can cause intratumoral arteriovenous shunts.展开更多
AIM To investigate whether normal thickness cartilage in osteoarthritic knees demonstrate depletion of proteoglycan or collagen content compared to healthy knees.METHODS Magnetic resonance(MR) images were acquired fro...AIM To investigate whether normal thickness cartilage in osteoarthritic knees demonstrate depletion of proteoglycan or collagen content compared to healthy knees.METHODS Magnetic resonance(MR) images were acquired from5 subjects scheduled for total knee arthroplasty(TKA)(mean age 70 years) and 20 young healthy control subjects without knee pain(mean age 28.9 years). MR images of T1ρ mapping, T2 mapping, and fat suppressed proton-density weighted sequences were obtained.Following TKA each condyle was divided into 4 parts(distal medial, posterior medial, distal lateral, posterior lateral) for cartilage analysis. Twenty specimens(bone and cartilage blocks) were examined. For each joint,the degree and extent of cartilage destruction was determined using the Osteoarthritis Research Society International cartilage histopathology assessment system.In magnetic resonance imaging(MRI) analysis, 2 readers performed cartilage segmentation for T1ρ/T2 values and cartilage thickness measurement.RESULTS Eleven areas in MRI including normal or near normal cartilage thickness were selected. The corresponding histopathological sections demonstrated mild to moderate osteoarthritis(OA). There was no significant difference in cartilage thickness in MRI between control and advanced OA samples [medial distal condyle, P = 0.461;medial posterior condyle(MPC), P = 0.352; lateral distal condyle, P = 0.654; lateral posterior condyle, P = 0.550],suggesting arthritic specimens were morphologically similar to normal or early staged degenerative cartilage.Cartilage T2 and T1ρ values from the MPC were significantly higher among the patients with advanced OA(P= 0.043). For remaining condylar samples there was no statistical difference in T2 and T1ρ values between cases and controls but there was a trend towards higher values in advanced OA patients. CONCLUSION Though cartilage is morphologically normal or near normal, degenerative changes exist in advanced OA patients. These changes can be detected with T2 and T1ρ MRI techniques.展开更多
Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tu...Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging(MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motionresistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management.展开更多
To investigate the prognostic value of the radiological response after transarterial chemoembolization (TACE) and inflammatory markers in patients affected by hepatocellular carcinoma (HCC) awaiting liver transplantat...To investigate the prognostic value of the radiological response after transarterial chemoembolization (TACE) and inflammatory markers in patients affected by hepatocellular carcinoma (HCC) awaiting liver transplantation (LT).METHODSWe retrospectively evaluated the preoperative predictors of HCC recurrence in 70 patients treated with conventional (n = 16) or doxorubicin-eluting bead TACE (n = 54) before LT. The patient and tumour characteristics, including the static and dynamic alpha-fetoprotein, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) measurements, were recorded. Treatment response was classified according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST) and the European Association for the Study of the Liver (EASL) criteria as complete response (CR), partial response (PR), stable disease or progressive disease. After examination of the explanted livers, histological necrosis was classified as complete (100% of the cumulative tumour area), partial (50%-99%) or minimal (< 50%) and was correlated with the preoperative radiological findings.RESULTSAccording to the pre-TACE radiological evaluation, 22/70 (31.4%) and 12/70 (17.1%) patients were beyond Milan and University of San Francisco (UCSF) criteria, respectively. After TACE procedures, the objective response (CR + PR) rates were 71.4% and 70.0% according to mRECIST and EASL criteria, respectively. The agreement between the two guidelines in defining the radiological response was rated as very good both for the overall and target lesion response (weighted k-value: 0.98 and 0.93, respectively). Complete and partial histological necrosis were achieved in 14/70 (20.0%) and 28/70 (40.0%) patients, respectively. Using histopathology as the reference standard, mRECIST criteria correctly classified necrosis in 72.9% (51/70) of patients and EASL criteria in 68.6% (48/70) of cases. The mRECIST non-response to TACE [Exp(b) = 9.2, p = 0.012], exceeding UCSF criteria before TACE [Exp(b) = 4.7, p = 0.033] and a preoperative PLR > 150 [Exp(b) = 5.9, p = 0.046] were independent predictors of tumour recurrence.CONCLUSIONThe radiological response and inflammatory markers are predictive of tumour recurrence and allow the proper selection of TACE-treated candidates for LT.展开更多
AIM:To present a dedicated series of transjugular intrahepatic porto-systemic shunts(TIPS) in the elderly since data is sparse on this population group.METHODS:A retrospective review was performed of patients at least...AIM:To present a dedicated series of transjugular intrahepatic porto-systemic shunts(TIPS) in the elderly since data is sparse on this population group.METHODS:A retrospective review was performed of patients at least 65 years of age who underwent TIPS at our institutions between 1997 and 2010.Twentyfive patients were referred for TIPS.We deemed that 2 patients were not considered appropriate candidates due to their markedly advanced liver disease.Of the 23 patients suitable for TIPS,the indications for TIPS placement was portal hypertension complicated by refractory ascites alone(n = 9),hepatic hydrothorax alone(n = 2),refractory ascites and hydrothorax(n = 1),gastrointestinal bleeding alone(n = 8),gastrointestinal bleeding and ascites(n = 3).RESULTS:Of these 23 attempted TIPS procedure patients,21 patients had technically successful TIPS procedures.A total of 29 out of 32 TIPS procedures including revisions were successful in 21 patients with a mean age of 72.1 years(range 65-82 years).Three of the procedures were unsuccessful attempts at TIPS and 8 procedures were successful revisions of our existing TIPS.Sixteen of 21 patients who underwent successful TIPS(excluding 5 patients lost to follow-up) were followed for a mean of 14.7 mo.Ascites and/or hydrothorax was controlled following technically successful procedures in 12 of 13 patients.Bleeding was controlled following technically successful procedures in 10 out of 11 patients.CONCLUSION:We have demonstrated that TIPS is an effective procedure to control refractory complications of portal hypertension in elderly patients.展开更多
Although the association between inflammatory bowel disease and gastrointestinal infections has been suggested, the mechanisms involved in the pathogenesis of Crohn's disease (CD) are still undetermined. We report ...Although the association between inflammatory bowel disease and gastrointestinal infections has been suggested, the mechanisms involved in the pathogenesis of Crohn's disease (CD) are still undetermined. We report the case of a man, who presented with mesenteric adenitis initially due to a Yersinia pseudotubercolosis infection, who was later diagnosed with Crohn's disease. This case is in keeping with recent evidence in the literature which suggests that CD is a disease linked to abnormal immune responses to enteric bacteria in genetically susceptible individuals.展开更多
Intrahepatic clear cell cholangiocarcinoma is very rareonly 8 cases have been reported.A 56-year-old Japanese man with chronic hepatitis B infection was diagnosed with a 2.2 cm hepatocellular carcinoma on imaging,and ...Intrahepatic clear cell cholangiocarcinoma is very rareonly 8 cases have been reported.A 56-year-old Japanese man with chronic hepatitis B infection was diagnosed with a 2.2 cm hepatocellular carcinoma on imaging,and hepatic segmentectomy was performed.Histopathologically,the tumor cells had copious clear cytoplasm and formed glandular structures or solid nests.These pathological findings suggested the tumor was a clear cell variant of intrahepatic cholangiocarcinoma.Particular stains and radiological images suggested that the cause of the clear cell change had been glycogen,not mucin nor lipid.On immunohistochemical staining,cytokeratin(CK)7 and CK19 were positive,whereas CK20 was negative.Vimentin was detected on the cell membranes,and CD56 was focally positive.The patient was given adjuvant chemotherapy and is currently free from the tumor 7 mo postoperatively.Careful follow-up with adequate postoperative supplementary chemotherapy is necessary because the characteristics of this type of tumor are unknown.展开更多
The main purpose of this work was to perform a rigorous computational study on scintimammography with a Mura-mask based on Monte Carlo simulation of voxelized breast phantoms. Three main objectives were addressed:(1) ...The main purpose of this work was to perform a rigorous computational study on scintimammography with a Mura-mask based on Monte Carlo simulation of voxelized breast phantoms. Three main objectives were addressed:(1) verification of Geant4 version 10.4,(2)optimization of the imaging setup, and(3) small tumor detection and localization. We successfully verified the Geant4-based imaging of a commonly used phantom in the field. We used a Mura-mask with a 41× 41 array pattern with adjustable thickness, material, and hole shape(box and cylinder);a low-energy high-resolution collimator with different hole shapes(cylinder and hexagon);and a voxelized breast phantom with different sizes(small, medium,and large) and glandularity percentages(low, medium, and high). We also compared the detector crystal outputs of CdZnTe and NaI(Tl). The simulation was followed by a deconvolution procedure, and the data(images) were statistically emphasized. Statistical metrics indicate that the Mura-mask(W material with 1.5 mm thickness and box holes) combined with a CdZnTe detector leads to the optimum point spread function. Finally, a preliminary study on small-sized tumor detection and localization was conducted with different tumor-to-background ratios(from2 to 12). Tumors with diameters of 5 and 8 mm could be detected, while those of 2 mm were undetectable. Nevertheless, this study enhances our understanding of the early detection of tumors in the field of scintimammography.展开更多
Computed tomography(CT)has earned a well-deserved role in diagnostic radiology,producing crosssectional and three-dimensional images which permit enhanced diagnosis of many pathogenic processes.The speed,versatility,a...Computed tomography(CT)has earned a well-deserved role in diagnostic radiology,producing crosssectional and three-dimensional images which permit enhanced diagnosis of many pathogenic processes.The speed,versatility,accuracy,and non-invasiveness of this procedure have resulted in a rapid increase in its use.CT imaging,however,delivers a substantially higher radiation dose than alternative imaging methodologies,particularly in children due to their smaller body dimensions.In addition,CT use in children produces an increased lifetime risk of cancer,as children’s developing organs and tissues are inherently more vulnerable to cellular damage than those of adults.Though individual risks are small,the increasing use of CT scans in children make this an important public health problem.Various organizations have recommended measures to minimize unnecessary exposures to radiation through CT scanning.These include elimination of multiple or medically unnecessary scans,development of patientspecific dosing guidelines,and use of alternative radiographic methodology wherever possible.Another important factor in excessive CT exposures,however,is a documented lack of awareness among medical practitioners of the doses involved in CT usage as well as itssignificant potential dangers.This review examines the effects of paediatric CT radiation,discusses the level of medical practitioner awareness of these effects,and offers recommendations on alternative diagnostic methods and practitioner education.展开更多
文摘BACKGROUND Gastrointestinal bleeding(GIB)is a severe and potentially life-threatening condition,especially in cases of delayed treatment.Computed tomography angiography(CTA)plays a pivotal role in the early identification of upper and lower GIB and in the prompt treatment of the haemorrhage.AIM To determine whether a volumetric estimation of the extravasated contrast at CTA in GIB may be a predictor of subsequent positive angiographic findings.METHODS In this retrospective single-centre study,35 patients(22 men;median age 69 years;range 16-92 years)admitted to our institution for active GIB detected at CTA and further submitted to catheter angiography between January 2018 and February 2022 were enrolled.Twenty-three(65.7%)patients underwent endoscopy before CTA.Bleeding volumetry was evaluated in both arterial and venous phases via a semi-automated dedicated software.Bleeding rate was obtained from volume change between the two phases and standardised for unit time.Patients were divided into two groups,according to the angiographic signs and their concordance with CTA.RESULTS Upper bleeding accounted for 42.9%and lower GIB for 57.1%.Mean haemoglobin value at the admission was 7.7 g/dL.A concordance between positive CTA and direct angiographic bleeding signs was found in 19(54.3%)cases.Despite no significant differences in terms of bleeding volume in the arterial phase(0.55 mL vs 0.33 mL,P=0.35),a statistically significant volume increase in the venous phase was identified in the group of patients with positive angiography(2.06 mL vs 0.9 mL,P=0.02).In the latter patient group,a significant increase in bleeding rate was also detected(2.18 mL/min vs 0.19 mL/min,P=0.02).CONCLUSION In GIB of any origin,extravasated contrast volumetric analysis at CTA could be a predictor of positive angiography and may help in avoiding further unnecessary procedures.
文摘In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.
文摘The current research aims to assess the staff and patients’ effective doses during Nuclear medicine (NM) bone scans procedures. The administered activity was utilized to quantify the patients’ effective doses, while personnel’s effective doses were quantified using thermoluminescent detectors (TLD-100). The average administered activity was 650 (440 to 1440) MBq procedures using SPECT gamma camera system. The average annual staff effective dose (mSv) was estimated to be 2.3 (0.1 to 4.9). The typical patient’s effective dose was 4.9 (3.6 to 6.0) mSv per procedure. Staff exposure within the yearly effective dose limits. Patients’ exposure optimization is required based on patient weight. Estimating staff eye lens doses is suggested to confirm that the yearly effective radiation doses are within the safety range.
文摘Acute abdominal pain is a medical emergency that is characterized by abrupt, acute, recently developed abdominal pain that is accompanied by other signs that are confined in the abdomen area. The purpose of this study was to illustrate how ultrasonography may be used to identify sudden abdominal pain. From December 2021 and March 2022, a comprehensive examination of 50 patients with acute abdominal pain was conducted. Seven hospitals in Khartoum State, Sudan, examined individuals with clinically suspected abdominal and pelvic deformities using 3.5 MHz ultrasound machines. Out of the 50 (100%) patients who were presented with acute abdominal pain 10 (20%) were appendicitis, 9 (18%) were cholecystitis, 8 (16%) were Nephrolithiasis, 3 (6%) were Choledocholithiasis, 3 (6%) were Chronic kidney disease, 3 (6%) were Cholelithiasis, 3 (6%) were Cystitis, 4 (8%) were Ascites, 1 (2%) was acute kidney injury, 1 (2%) was Acute Peritonitis, 1 (2%) was Diverticulum and 1 (2%) each was of Epigastric hernia, Hepatosplenomegaly, Liver cirrhosis, Nephritis and Ovarian cysts respectively. According to the study results, ultrasonography (US) proceeds to be the go-to imaging strategy in most situations, particularly for younger and female patients, where limiting exposure to radiation must be obligated. The application of Computerized Tomography CT should be restricted in circumstances where there is no diagnostic US and, in all situations, where there is a significant disparity between medical symptoms and negative imaging in the US.
文摘Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer.Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared.Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS.Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.
文摘Pulmonary nodules are small, round, or oval-shaped growths on the lungs. They can be benign (noncancerous) or malignant (cancerous). The size of a nodule can range from a few millimeters to a few centimeters in diameter. Nodules may be found during a chest X-ray or other imaging test for an unrelated health problem. In the proposed methodology pulmonary nodules can be classified into three stages. Firstly, a 2D histogram thresholding technique is used to identify volume segmentation. An ant colony optimization algorithm is used to determine the optimal threshold value. Secondly, geometrical features such as lines, arcs, extended arcs, and ellipses are used to detect oval shapes. Thirdly, Histogram Oriented Surface Normal Vector (HOSNV) feature descriptors can be used to identify nodules of different sizes and shapes by using a scaled and rotation-invariant texture description. Smart nodule classification was performed with the XGBoost classifier. The results are tested and validated using the Lung Image Consortium Database (LICD). The proposed method has a sensitivity of 98.49% for nodules sized 3–30 mm.
文摘AIM To establish a threshold value for liver fat content between healthy children and those with nonalcoholic fatty liver disease(NAFLD) by using magnetic resonance imaging(MRI), with liver biopsy serving as a reference standard. METHODS The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel pointresolved 1H MR-Spectroscopy(1H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cutoff value. Lin coefficient test was used to evaluate thecorrelation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables. RESULTS According to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF.CONCLUSION MRS is an accurate and precise method for detecting NAFLD in children.
文摘In this study, to explore the radiation protection effects of Lyophyllum Decastes Sing (LDS), a hot distilled-water extract of LDS was orally administered at a dosage of 250mg/kg every other day for a period of 2 weeks in irradiated mice. An automatic blood cell counter was used to measure white blood cells (lymphocytes, monocyte, and granulocytes) one day before X-ray irradiation, and 3 hours, 12 hours, 24 hours, 3 days, 7 days, 15 days and 30 days after irradiation. The Dunnett test was used to examine statistical significance of differences. The peripheral blood cell counts in the Lyophyllum-administered non-irradiation group revealed an increase in the numbers of ieukocytes, lymphocytes and monocytes. For 2 Gy whole body radiation, a significant statistical difference was found between the X-ray group and the Lyophyllum plus X-ray group in the numbers of leukocytes, lymphocytes and monocytes. The results suggest that Lyophyllum restrains blood cell-count falling after irradiation, which is probably mediated at least in part by hemopoietic function, and NK and LAK activities seems to play a role in preventing secondary irffections associated with irradiation.
文摘AIM: To analyze contrast-enhanced ultrasound(CEUS) features of histologically proven hepatic epithelioid hemangioendothelioma(HEHE) in comparison to other multilocular benign focal liver lesions(FLL).METHODS: Twenty-five patients with histologically proven HEHE and 45 patients with histologically proven multilocular benign FLL were retrospectively reviewed. Four radiologists assessed the CEUS enhancement pattern in consensus.RESULTS: HEHE manifested as a single(n = 3) or multinodular(n = 22) FLL. On CEUS, HEHE showed rim-like(18/25, 72%) or heterogeneous hyperenhancement(7/25, 28%) in the arterial phase and hypoenhancement(25/25, 100%) in the portal venous and late phases(PVLP), a sign of malignancy. Eighteen patients showed central unenhanced areas(18/25, 72%); in seven patients(7/25, 28%), more lesions were detected in the PVLP. In contrast, all patients with hemangioma and focal nodular hyperplasia showed hyperenhancement as the most distinctive feature(P < 0.01).CONCLUSION: CEUS allows for characterization of unequivocal FLL. By analyzing the hypoenhancement in the PVLP, CEUS can determine the malignant nature of HEHE.
文摘Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy.The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and colonoscopy.However,despite the fact that CTC has been officially endorsed for CRC screening of average-risk individuals by different scientif ic societies including the American Cancer Society,the American College of Radiology,and the US Multisociety Task Force on Colorectal Cancer,other entities,such as the US Preventive Services Task Force,have considered the evidence insuff icient to justify its use as a mass screening method.Medicare has also recently denied reimbursement for CTC as a screening test.Nevertheless,multiple advantages exist for using CTC as a CRC screening test:high accuracy,full evaluation of the colon in virtually all patients,non-invasiveness,safety,patient comfort,detection of extracolonic findings and cost-effectiveness.The main potential drawback of a CTC screening is the exposure to ionizing radiation.However,this is not a major issue,since low-dose protocols are now routinely implemented,delivering a dose comparable or slightly superior to the annual radiation exposure of any individual.Indirect evidence exists that such a radiation exposure does not induce additional cancers.
文摘A male patient underwent conventional transcatheter chemoembolization for advanced recurrent hepatocellular carcinoma(HCC). Even after the injection of 7 m L of lipiodol followed by gelatin sponge particles, the flow of feeding arteries did not slow down. A repeat angiography revealed a newly developed vascular lake draining into systemic veins; however, embolization was continued without taking noticing of the vascular lake. The patient's level of consciousness deteriorated immediately after the procedure, and non-contrast computed tomography revealed pulmonary and cerebral lipiodol embolisms. The patient's level of consciousness gradually improved after 8 wk in intensive care. In this case, a vascular lake emerged during chemoembolization and drained into systemic veins, offering a pathway carrying lipiodol to pulmonary vessels, the most likely cause of this serious complication. We should be aware that vascular lakes in HCC may drain into systemic veins and can cause intratumoral arteriovenous shunts.
基金Supported by The National Center for Research Resources and the National Center for Advancing Translational Sciences,National Institutes of Health,No.UL1 TR000153
文摘AIM To investigate whether normal thickness cartilage in osteoarthritic knees demonstrate depletion of proteoglycan or collagen content compared to healthy knees.METHODS Magnetic resonance(MR) images were acquired from5 subjects scheduled for total knee arthroplasty(TKA)(mean age 70 years) and 20 young healthy control subjects without knee pain(mean age 28.9 years). MR images of T1ρ mapping, T2 mapping, and fat suppressed proton-density weighted sequences were obtained.Following TKA each condyle was divided into 4 parts(distal medial, posterior medial, distal lateral, posterior lateral) for cartilage analysis. Twenty specimens(bone and cartilage blocks) were examined. For each joint,the degree and extent of cartilage destruction was determined using the Osteoarthritis Research Society International cartilage histopathology assessment system.In magnetic resonance imaging(MRI) analysis, 2 readers performed cartilage segmentation for T1ρ/T2 values and cartilage thickness measurement.RESULTS Eleven areas in MRI including normal or near normal cartilage thickness were selected. The corresponding histopathological sections demonstrated mild to moderate osteoarthritis(OA). There was no significant difference in cartilage thickness in MRI between control and advanced OA samples [medial distal condyle, P = 0.461;medial posterior condyle(MPC), P = 0.352; lateral distal condyle, P = 0.654; lateral posterior condyle, P = 0.550],suggesting arthritic specimens were morphologically similar to normal or early staged degenerative cartilage.Cartilage T2 and T1ρ values from the MPC were significantly higher among the patients with advanced OA(P= 0.043). For remaining condylar samples there was no statistical difference in T2 and T1ρ values between cases and controls but there was a trend towards higher values in advanced OA patients. CONCLUSION Though cartilage is morphologically normal or near normal, degenerative changes exist in advanced OA patients. These changes can be detected with T2 and T1ρ MRI techniques.
文摘Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging(MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motionresistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management.
文摘To investigate the prognostic value of the radiological response after transarterial chemoembolization (TACE) and inflammatory markers in patients affected by hepatocellular carcinoma (HCC) awaiting liver transplantation (LT).METHODSWe retrospectively evaluated the preoperative predictors of HCC recurrence in 70 patients treated with conventional (n = 16) or doxorubicin-eluting bead TACE (n = 54) before LT. The patient and tumour characteristics, including the static and dynamic alpha-fetoprotein, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) measurements, were recorded. Treatment response was classified according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST) and the European Association for the Study of the Liver (EASL) criteria as complete response (CR), partial response (PR), stable disease or progressive disease. After examination of the explanted livers, histological necrosis was classified as complete (100% of the cumulative tumour area), partial (50%-99%) or minimal (< 50%) and was correlated with the preoperative radiological findings.RESULTSAccording to the pre-TACE radiological evaluation, 22/70 (31.4%) and 12/70 (17.1%) patients were beyond Milan and University of San Francisco (UCSF) criteria, respectively. After TACE procedures, the objective response (CR + PR) rates were 71.4% and 70.0% according to mRECIST and EASL criteria, respectively. The agreement between the two guidelines in defining the radiological response was rated as very good both for the overall and target lesion response (weighted k-value: 0.98 and 0.93, respectively). Complete and partial histological necrosis were achieved in 14/70 (20.0%) and 28/70 (40.0%) patients, respectively. Using histopathology as the reference standard, mRECIST criteria correctly classified necrosis in 72.9% (51/70) of patients and EASL criteria in 68.6% (48/70) of cases. The mRECIST non-response to TACE [Exp(b) = 9.2, p = 0.012], exceeding UCSF criteria before TACE [Exp(b) = 4.7, p = 0.033] and a preoperative PLR > 150 [Exp(b) = 5.9, p = 0.046] were independent predictors of tumour recurrence.CONCLUSIONThe radiological response and inflammatory markers are predictive of tumour recurrence and allow the proper selection of TACE-treated candidates for LT.
文摘AIM:To present a dedicated series of transjugular intrahepatic porto-systemic shunts(TIPS) in the elderly since data is sparse on this population group.METHODS:A retrospective review was performed of patients at least 65 years of age who underwent TIPS at our institutions between 1997 and 2010.Twentyfive patients were referred for TIPS.We deemed that 2 patients were not considered appropriate candidates due to their markedly advanced liver disease.Of the 23 patients suitable for TIPS,the indications for TIPS placement was portal hypertension complicated by refractory ascites alone(n = 9),hepatic hydrothorax alone(n = 2),refractory ascites and hydrothorax(n = 1),gastrointestinal bleeding alone(n = 8),gastrointestinal bleeding and ascites(n = 3).RESULTS:Of these 23 attempted TIPS procedure patients,21 patients had technically successful TIPS procedures.A total of 29 out of 32 TIPS procedures including revisions were successful in 21 patients with a mean age of 72.1 years(range 65-82 years).Three of the procedures were unsuccessful attempts at TIPS and 8 procedures were successful revisions of our existing TIPS.Sixteen of 21 patients who underwent successful TIPS(excluding 5 patients lost to follow-up) were followed for a mean of 14.7 mo.Ascites and/or hydrothorax was controlled following technically successful procedures in 12 of 13 patients.Bleeding was controlled following technically successful procedures in 10 out of 11 patients.CONCLUSION:We have demonstrated that TIPS is an effective procedure to control refractory complications of portal hypertension in elderly patients.
文摘Although the association between inflammatory bowel disease and gastrointestinal infections has been suggested, the mechanisms involved in the pathogenesis of Crohn's disease (CD) are still undetermined. We report the case of a man, who presented with mesenteric adenitis initially due to a Yersinia pseudotubercolosis infection, who was later diagnosed with Crohn's disease. This case is in keeping with recent evidence in the literature which suggests that CD is a disease linked to abnormal immune responses to enteric bacteria in genetically susceptible individuals.
文摘Intrahepatic clear cell cholangiocarcinoma is very rareonly 8 cases have been reported.A 56-year-old Japanese man with chronic hepatitis B infection was diagnosed with a 2.2 cm hepatocellular carcinoma on imaging,and hepatic segmentectomy was performed.Histopathologically,the tumor cells had copious clear cytoplasm and formed glandular structures or solid nests.These pathological findings suggested the tumor was a clear cell variant of intrahepatic cholangiocarcinoma.Particular stains and radiological images suggested that the cause of the clear cell change had been glycogen,not mucin nor lipid.On immunohistochemical staining,cytokeratin(CK)7 and CK19 were positive,whereas CK20 was negative.Vimentin was detected on the cell membranes,and CD56 was focally positive.The patient was given adjuvant chemotherapy and is currently free from the tumor 7 mo postoperatively.Careful follow-up with adequate postoperative supplementary chemotherapy is necessary because the characteristics of this type of tumor are unknown.
基金supported by The National Plan for Science,Technology and Innovation(MAARIFAH)King Abdulaziz City for Science and Technology,Kingdom of Saudi Arabia,Award Number(12-MED2516-02)
文摘The main purpose of this work was to perform a rigorous computational study on scintimammography with a Mura-mask based on Monte Carlo simulation of voxelized breast phantoms. Three main objectives were addressed:(1) verification of Geant4 version 10.4,(2)optimization of the imaging setup, and(3) small tumor detection and localization. We successfully verified the Geant4-based imaging of a commonly used phantom in the field. We used a Mura-mask with a 41× 41 array pattern with adjustable thickness, material, and hole shape(box and cylinder);a low-energy high-resolution collimator with different hole shapes(cylinder and hexagon);and a voxelized breast phantom with different sizes(small, medium,and large) and glandularity percentages(low, medium, and high). We also compared the detector crystal outputs of CdZnTe and NaI(Tl). The simulation was followed by a deconvolution procedure, and the data(images) were statistically emphasized. Statistical metrics indicate that the Mura-mask(W material with 1.5 mm thickness and box holes) combined with a CdZnTe detector leads to the optimum point spread function. Finally, a preliminary study on small-sized tumor detection and localization was conducted with different tumor-to-background ratios(from2 to 12). Tumors with diameters of 5 and 8 mm could be detected, while those of 2 mm were undetectable. Nevertheless, this study enhances our understanding of the early detection of tumors in the field of scintimammography.
文摘Computed tomography(CT)has earned a well-deserved role in diagnostic radiology,producing crosssectional and three-dimensional images which permit enhanced diagnosis of many pathogenic processes.The speed,versatility,accuracy,and non-invasiveness of this procedure have resulted in a rapid increase in its use.CT imaging,however,delivers a substantially higher radiation dose than alternative imaging methodologies,particularly in children due to their smaller body dimensions.In addition,CT use in children produces an increased lifetime risk of cancer,as children’s developing organs and tissues are inherently more vulnerable to cellular damage than those of adults.Though individual risks are small,the increasing use of CT scans in children make this an important public health problem.Various organizations have recommended measures to minimize unnecessary exposures to radiation through CT scanning.These include elimination of multiple or medically unnecessary scans,development of patientspecific dosing guidelines,and use of alternative radiographic methodology wherever possible.Another important factor in excessive CT exposures,however,is a documented lack of awareness among medical practitioners of the doses involved in CT usage as well as itssignificant potential dangers.This review examines the effects of paediatric CT radiation,discusses the level of medical practitioner awareness of these effects,and offers recommendations on alternative diagnostic methods and practitioner education.