Rim^(18)F-fluorodeoxyglucose uptake of hepatic cavernous hemangioma on positron emission tomography/computed tomography:A case report

BACKGROUND Peripheral FDG accumulation in a hepatic hemangioma presenting in a patient with prolonged fever is rare.Therefore,clinicians should pay close attention to patients with hepatic mass.CASE SUMMARY A 54-year-old woman with a 4-wk history of daily fevers was admitted to our hospital.A whole body^(18)-Fluordesoxyglucose(PET-FDG)positron emission tomography/computed tomography(PET/CT)was performed to elucidate the source of the fever.However,whole body^(18)-FDG PET/CT raised the suspicion of a malignant lesion because of peripheral FDG accumulation(SUVmax 3.5 g/mL)higher than that of the normal liver parenchyma(SUVmax 1.6 g/mL)surrounding a hypoactive area,and no other abnormalities were showed.Subsequently,the patient underwent liver mass resection.Histopathology showed a hepatic cavernous hemangioma with fatty infiltration around the lesion.The fever disappeared four days after surgery and the patient did not present any complications during follow-up.CONCLUSION Fatty infiltration in the peripheral parts of hepatic cavernous hemangioma may lead to subacute inflammation which further activate the Kupffer cells.This may cause prolonged fever and peripheral rim FDG accumulation on PET/CT.

Effectiveness of magnetic resonance imaging and spiral computed tomography in the staging and treatment prognosis of colorectal cancer

BACKGROUND Colorectal cancer(CRC)is a prevalent cancer type in clinical settings;its early signs can be difficult to detect,which often results in late-stage diagnoses in many patients.The early detection and diagnosis of CRC are crucial for improving treatment success and patient survival rates.Recently,imaging techniques have been hypothesized to be essential in managing CRC,with magnetic resonance imaging(MRI)and spiral computed tomography(SCT)playing a significant role in enhancing diagnostic and treatment approaches.AIM To explore the effectiveness of MRI and SCT in the preoperative staging of CRC and the prognosis of laparoscopic treatment.METHODS Ninety-five individuals admitted to Zhongshan Hospital Xiamen University underwent MRI and SCT and were diagnosed with CRC.The precision of MRI and SCT for the presurgical classification of CRC was assessed,and pathological staging was used as a reference.Receiver operating characteristic curves were used to evaluate the diagnostic efficacy of blood volume,blood flow,time to peak,permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction on the prognosis of patients with CRC.RESULTS Pathological biopsies confirmed the following CRC stages:23,23,32,and 17 at T1,T2,T3,and T4,respectively.There were 39 cases at the N0 stage,22 at N1,34 at N2,44 at M0 stage,and 51 at M1.Using pathological findings as the benchmark,the combined use of MRI and SCT for preoperative TNM staging in patients with CRC demonstrated superior sensitivity,specificity,and accuracy compared with either modality alone,with a statistically significant difference in accuracy(P<0.05).Receiver operating characteristic curve analysis revealed the predictive values for laparoscopic treatment prognosis,as indicated by the areas under the curve for blood volume,blood flow,time to peak,and permeability surface,blood reflux constant,volume transfer constant,and extracellular extravascular space volume fraction were 0.750,0.683,0.772,0.761,0.709,0.719,and 0.910,respectively.The corresponding sensitivity and specificity values were also obtained(P<0.05).CONCLUSION MRI with SCT is effective in the clinical diagnosis of patients with CRC and is worthy of clinical promotion.

Efficacy of multi-slice spiral computed tomography in evaluating gastric cancer recurrence after endoscopic submucosal dissection

BACKGROUND Recurrence is the major challenge facing endoscopic submucosal dissection(ESD)-based treatment therapies for early gastric cancer(EGC).Urgent development of simple and easy surveillance approaches will enhance clinical treatment of the disease.AIM To explore the role of computed tomography(CT)recurrence in evaluating EGC after ESD treatment.METHODS We retrospectively recruited patients from our endoscopy department,between January 2002 and December 2015,and analyzed their basic characteristics,including symptoms,CT results,and results of endoscopy with biopsy,among others.RESULTS Among a total of 2150 patients EGC patients surveyed,1362 met our inclusion and exclusion criteria and were therefore enrolled in our study.The cohort’s sensitivity of CT for recurrent GC and specificity were 44.22%and 43.86%,respectively,with negative and positive predictive values of 40.15%(275/685)and 48.01%(325/677),respectively.The area under the curve of arterial and venous CT values for recurrent EGC were 0.545,and 0.604,respectively.Receiver operating characteristic curve revealed no statistically significant differences between arterial and venous CT values for recurrent EGC.CONCLUSION Enhanced CT has superior diagnostic efficacy,but less accuracy,compared to gold standard techniques in patients with recurrent EGC.

Evaluation of response to gemcitabine plus cisplatin-based chemotherapy using positron emission computed tomography for metastatic bladder cancer

BACKGROUND The purpose of the present study was to examine retrospectively the contribution of 18Fluorodeoxyglucose positron emission tomography computed tomography(18FDG-PET/CT)to the evaluation of response to first-line gemcitabine plus cispla-tin-based chemotherapy in patients with metastatic bladder cancer.AIM To evaluate the response to Gemcitabine plus Cisplatin-based chemotherapy using 18FDG-PET/CT imaging in patients with metastatic bladder cancer.METHODS Between July 2007 and April 2019,79 patients underwent 18FDG-PET/CT imaging with the diagnosis of Metastatic Bladder Carcinoma(M-BCa).A total of 42 pa-tients(38 male,4 female)were included in the study,and all had been admi-nistered Gemcitabine plus Cisplatin-based chemotherapy.After completion of the therapy,the patients underwent a repeat 18FDG-PET/CT scan and the results were compared with the PET/CT findings before chemotherapy according to European Organisation for the Research and treatment of cancer criteria.Mean age was 66.1 years and standard deviation was 10.7 years(range:41–84 years).RESULTS Of the patients,seven(16.6%)were in complete remission,17(40.5%)were in partial remission,six(14.3%)had a stable disease,and 12(28.6%)had a pro-gressive disease.The overall response rate was 57.1 percent.CONCLUSION 18FDG-PET/CT can be considered as a successful imaging tool in evaluating response to first-line chemotherapy for metastatic bladder cancer.Anatomical and functional data obtained from PET/CT scans may be useful in the planning of secondline and thirdline chemotherapy.

Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols

Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.

Appearance of aseptic vascular grafts after endovascular aortic repair on[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography

BACKGROUND Diagnosis of prosthetic vascular graft infection with[(18)F]fluorodeoxyglucose positron emission tomography/computed tomography(18F-FDG PET/CT)allows for early detection of functional changes associated with infection,based on increased glucose utilization by activated macrophages and granulocytes.Aseptic vascular grafts,like all foreign bodies,can stimulate an inflammatory response,which can present as increased activity on 18F-FDG PET/CT.Consequently,distinguishing aseptic inflammation from graft infection,though important,can be difficult.In the case of endovascular aneurysm repair(EVAR),a minimally invasive procedure involving the transfemoral insertion of an endoprosthetic stent graft,the normal postoperative appearance of these grafts on 18F-FDG PET/CT can vary over time,potentially confounding study interpretation.AIM To investigate the visual,semiquantitative,and temporal characteristics of aseptic vascular grafts in patients status post EVAR.METHODS In this observational retrospective cohort study,patients with history of EVAR who underwent 18F-FDG PET/CT for indications other than infection were identified retrospectively.All patients were asymptomatic for graft infection-no abdominal pain,fever of unknown origin,sepsis,or leukocytosis-at the time of imaging and for≥2 mo after each PET/CT.Imaging studies such as CT for each patient were also reviewed,and any patients with suspected or confirmed vascular graft infection were excluded.One hundred two scans performed on 43 patients(34 males;9 females;age=77±8 years at the time of the final PET/CT)were retrospectively reviewed.All 43 patients had an abdominal aortic(AA)vascular graft,40 patients had a right iliac(RI)limb graft,and 41 patients had a left iliac(LI)limb graft.Twentytwo patients had 1 PET/CT and 21 patients had from 2 to 9 PET/CTs.Grafts were imaged between 2 mo to 168 mo(about 14 years)post placement.Eight grafts were imaged within 6 mo of placement,including three that were imaged within three months of placement.The mean interval between graft placement and PET/CT for all 102 scans was 51±39 mo.PET/CT data was reconstructed with region-of-interest analysis of proximal,mid and distal portions of the grafts and background ascending aorta.Maximum standardized uptake value(SUVmax)was recorded for each region.SUVmax-to-background uptake ratios(URs)were calculated.Visual assessment was performed using a 2-pattern grading scale:Diffuse(homogeneous uptake less than liver uptake)and focal(one or more areas of focal uptake in any part of the graft).Statistical analysis was performed.RESULTS In total,there were 306 AA grafts,285 LI grafts,282 RI grafts,and 306 ascending aorta background SUVmax measurements.For all 102 scans,mean SUVmax values for AA grafts were 2.8-3.0 along proximal,mid,and distal segments.Mean SUVmax values for LI grafts and RI grafts were 2.7-2.8.Mean SUVmax values for background were 2.5±0.5.Mean URs were 1.1-1.2.Visual analysis of the scans reflected results of quantitative analysis.On visual inspection,98%revealed diffuse,homogeneous 18F-FDG uptake less than liver.Graft URs and visual pattern categories were significantly associated for AA graft URs(F-ratio=21.5,P<0.001),LI graft URs(F-ratio=20.4,P<0.001),and RI graft URs(F-ratio=30.4,P<0.001).Thus,visual patterns of 18F-FDG uptake corresponded statistically significantly to semiquantitative URs.The age of grafts showing focal patterns was greater than grafts showing diffuse patterns,87±89 vs 50±37 mo,respectively(P=0.02).URs were significantly associated with graft age for AA grafts(r=0.19,P=0.001).URs were also significantly associated with graft age for LI grafts(r=0.25,P<0.0001),and RI grafts(r=0.31,P<0.001).Quartiles of similar numbers of graft(n=25-27)grouped by graft age indicated that URs were significantly higher for 4th quartile vs 2nd quartile URs(F-ratio=19.5,P<0.001).When evaluating URs,graft SUVmax values within 10%-20%of the ascending aorta SUVmax is evident in aseptic grafts,except for grafts in the oldest quartiles.In this study,grafts in the oldest quartiles(>7 years post EVAR)showed SUVmax up to 30%higher than the ascending aorta SUVmax.CONCLUSION Characteristics of an aseptic vascular stent graft in the aorta and iliac vessels on 18F-FDG PET/CT include graft SUVmax values within 10%-20%of the ascending aorta background SUVmax.The SUVmax of older aseptic grafts can be as much as 30%above background.The visual uptake pattern of diffuse,homogeneous uptake less than liver was seen in 98%of aseptic vascular grafts,making this pattern particularly reassuring for clinicians.

Portal vein computed tomography imaging characteristics and their relationship with bleeding risk in patients with liver cirrhosis undergoing interventional therapy

BACKGROUND This study aimed to analyze the predictive value of multi-slice spiral computed tomography(CT)perfusion imaging for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.A total of 62 patients with cirrhotic portal hypertension and 28 healthy individuals were included.The results showed that multi-slice spiral CT perfusion imaging had a significant predictive value for upper gastrointestinal bleeding in patients with cirrhotic portal hypertension.The vascular area,number of vascular cross-sections,and gastric coronary vein diameter(GCVD)showed high predictive values,with the vascular area having the best predictive value.AIM To investigate the predictive accuracy of multi-slice spiral CT perfusion imaging for upper gastrointestinal bleeding in patients with cirrhosis and portal hypertension.METHODS This study included 62 patients with cirrhotic portal hypertension(disease group)and 28 healthy individuals(control group).The disease group was further divided into two subgroups:Group A(n=27,bleeding)and group B(n=35,no bleeding).All patients underwent multi-slice spiral CT perfusion imaging at our hospital,and we compared various parameters such as liver blood flow,vein size,number of blood vessels,and blood vessel area between the two groups.We employed statistical analysis to identify factors associated with upper gastrointestinal bleeding and created a graph comparing the predictive value of different factors for bleeding.RESULTS We found no difference in hepatic artery(HAP)levels among the three groups(all P>0.05).The portal vein levels in groups A and B were much lower than in the control group;group A was much lower than group B(all P<0.05).The HAP perfusion index levels in groups A and B were much higher than in the control group;group A was much higher than group B(all P<0.05).The portal vein diameter,splenic vein diameter,and GCVD levels in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The number of blood vessels and blood vessel area in groups A and B were much higher than in the control group;those in group A were much higher than those in group B(all P<0.05).The statistical method showed a strong link between GCVD,number of blood vessels,blood vessel area,and upper gastrointestinal bleeding(odds ratio=1.275,1.346,1.397,P<0.05).The graph showed that GCVD,number of blood vessels,and blood vessel area could predict bleeding well,with blood vessel area having the best prediction power.CONCLUSION That multi-slice spiral CT perfusion imaging can predict upper gastrointestinal bleeding well in patients with cirrhosis and high blood pressure in the portal vein.GCVD,number of blood vessels,and blood vessel area had high prediction power.The blood vessel area had the best prediction power,with an area under the curve of 0.831.

Clinical role of (18)~F-fluorodeoxyglucose positron emission tomography/computed tomography in post-operative follow up of gastric cancer: Initial results

AIM: To evaluate the clinical role of 18F-fluorodeo-xyglucose positron emission and computed tomography (18F-FDG PET/CT) in detection of gastric cancer recurrence after initial surgical resection. METHODS: In the period from January 2007 to May 2008, 23 patients who had previous surgical resection of histopathologically diagnosed gastric cancer underwent a total of 25 18F-FDG PET/CT scans as follow-up visits in our center. The standard of reference for tumor recurrence consisted of histopathologic confirmation or clinical follow-up information for at least 5 mo after PET/CT examinations. RESULTS: PET/CT was positive in 14 patients (61%) and negative in 9 (39%). When correlated with final diagnosis, which was confirmed by histopathologic evidence of tumor recurrence in 8 of the 23 patients (35%) and by clinical follow-up in 15 (65%), PET/CT was true positive in 12 patients, false positive in 2, true negative in 8 and false negative in 2. Overall, the accuracy of PET/CT was 82.6%, the negative predictive value (NPV) was 77.7%, and the positive predictive value (PPV) was 85.7%. The 2 false positive PET/CT findings were actually chronic inflammatory tissue lesions. For the two patients with false negativePET/CT, the f inal diagnosis was recurrence of mucinous adenocarcinoma in the anastomosis in one patient and abdominal wall metastasis in the other. Importantly, PET/CT revealed true-positive findings in 11 (47.8%) patients who had negative or no definite findings by CT. PET/CT revealed extra-abdominal metastases in 7 patients and additional esophageal carcinoma in one patient. Clinical treatment decisions were changed in 7 (30.4%) patients after introducing PET/CT into their conventional post-operative follow-up program. CONCLUSION: Whole body 18F-FDG PET/CT was highly effective in discriminating true recurrence in post-operative patients with gastric cancer and had important impacts on clinical decisions in a considerable portion of patients.

^(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM To compare ^(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ^(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P < 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

AIM: To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases. METHODS: A total of 138 patients with HCC who had both conventional imaging modalities and 18F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled. Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated. Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods. RESULTS: The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases. The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13 (92.3%), when < 1 cm was 2/10 (20%) in PET imaging. The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases. In multivariate analy- sis, increased tumor size (≥ 5 cm) (P = 0.042) and increased average standardized uptake value (SUV) uptake (P = 0.028) were predictive factors for extrahepatic metastases. Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P = 0.035). According to the receiver operating characteristic curve, the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4. CONCLUSION: 18F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases. Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4 should be considered for extrahepatic metastases.

Diagnostic ability of multi-detector spiral computed tomography for pathological lymph node metastasis of advanced gastric cancer

BACKGROUND The reliability of preoperative nodal diagnosis of advanced gastric cancer by multi-detector spiral computed tomography(MDCT)is still unclear.AIM To examine the diagnostic ability of MDCT more precisely by using data on intranodal pathological metastatic patterns.METHODS A total of 108 patients with advanced gastric cancer who underwent MDCT and curative gastrectomy at Kanazawa Medical University Hospital were enrolled in this study.The nodal sizes measured on computed tomography(CT)images were compared with the pathology results.A receiver-operating characteristic curve was constructed,from which the critical value(CV)was calculated by using the data of the first 69 patients retrospectively.By using the CV,sensitivity and specificity were calculated with prospectively collected data from 39 consecutive patients.This enabled a more precise one-to-one correspondence of lymph nodes between CT and pathological examination by using the size data of lymph node mapping.The intranodal pathological metastatic patterns were classified into the following four types:Small nodular,peripheral,large nodular,and diffuse.RESULTS Although all the cases were clinically suspected as having metastasis,81 had lymph node metastasis and 27 had no metastasis.The number of dissected,detected on CT,and metastatic nodes were,4241,897,and 801,respectively.The CV obtained from the receiver-operating characteristic was 7.6 mm for the long axis.The sensitivity was 91.4%and the specificity was 47.3%in the prospective phase.The large nodular and diffuse metastases were easy to diagnose becausemetastatic nodes with a large axis often exhibit these forms.CONCLUSION The ability of MDCT to contribute to a nodal diagnosis of advanced gastric cancer was examined prospectively with precise size data from node mapping,using a CV of 7.6 mm for the long axis that was calculated from the retrospectively collected data.The sensitivity was as high as 91%,and would be improved when referring to the enhanced patterns.However,its specificity was as low as 47%,because most of metastatic nodes in gastric cancer being small in size.The small nodular or peripheral type metastatic nodes were often small and considered difficult to diagnose.

Whole Body Positron Emission Tomography/Computed Tomography （PET/CT） in the Evaluation of Ophthalmic Tumors

The clinical value of whole body positron emission tomography/computed tomography （PET/CT） as an imaging tool in diagnosis of ophthalmic tumors was investigated. The retrospective observational case series were performed on the patients with suspected ophthalmic tumors who underwent whole body PET/CT. The golden standard of diagnosis was the final pathological diagnosis or the results of long-term follow-up for patients without surgery/ biopsy. PET/CT findings were compared with the golden standard. The sensitivity, specificity, accuracy an^t positive likelihood ratio of PET/CT in the detection of ophthalmic tumors were calculated. The clinical application of PET/CT in different types of ophthalmic tumors was evaluated. The results showed that 30 patients （18 males and 12 females） with a mean age of 43.0 years （range 4-63 years） were collected. The mean sizes of orbital tumors and intraocular tumors were 26.8 mmxl7.8 mm and 11.2 minx6.1 mm, respectively. The overall sensitivity, specificity, accuracy and positive likelihood ratio of whole body PET/CT in ophthalmic tumors were 76.5%, 71.4%, 75.0% and 2.67, and were 62.5%, 100% and 70.0% in intraocular tumors, and those were 100%, 60.0% and 84.6% in orbital tumors, respectively. PET/CT findings were applied to help make appropriate treatment options in 27 out of 30 patients （90.0%）, and 12 （40.0%） patients changed the treatment strategy. False negative results in 4 cases and false positive results in 2 cases were observed in this series. It was suggested that PET/CT was an effective imaging modality in detecting, diagnosing and developing therapeutic schedule for patients with ophthalmic tumors. It was more sensitive and accurate for detecting orbital tumors than for detecting intraocular tumors.

Segmental radiofrequency ablation of pulmonary vein ostia for patients with refractory paroxysmal atrial fibrillation using multi-slice spiral computed tomography guidance

Objective： To evaluate the safety and clinical efficacy of segmental radiofrequency ablation of pulmonary vein （PV） ostia for patients with refractory paroxysmal atrial fibrillation （AF） under multi-slice spiral computed tomography （MSCT） guidance before the procedure. Methods： A series of 58 consecutive patients with refractory paroxysmal AF were enrolled to undergo segmental radiofrequency ablation ofPV ostia. The 36 male and 22 female patients with mean age of （57.4±9.5） （32-79） years and no obvious organic heart disease. Before ablation, patients received MSCT to generate 3-dimentional image of the left atrium （LA） and proximal PVs. Patients then underwent segmental radiofrequency ablation ofPV ostia using PV circular mapping catheter manipulated several times to ensure complete isolation between PVs and LA. Results： No complications occurred during the procedure. One patient developed delayed cardiac tamponade, which was drained percutaneously. The mean follow-up time was （17.1±9.3） months. Forty-one patients （95%） experienced improved quality of life one month after the procedure. Thirty-six patients （83%） showed stable sinus rhythm, while 10 patients （23%） required additional anti-arrhythmic drugs. AF returned≥1 time in 6 （14%） patients who underwent anti-arrhythmic drug therapy, but the number of episodes was less than that before the procedure. However, one patient experienced recurrent episodes of atrial flutter. Conclusion： It is safe and effective to perform segmental radiofrequency ablation of PV ostia for patients with refractory paroxysmal AF using MSCT guidance mappening.

Incidental focal colorectal ^(18)F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography

AIM: To assess the clinical significance of incidental focal colorectal 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on 18 F-FDG-positron emission tomography/computed tomography (PET/CT). METHODS: The records of all the cases which had undergone colonoscopy after PET/CT within a two weeks interval were reviewed. Adenomas were considered advanced when they were villous, ≥ 10 mm in size, or had high-grade dysplasia. Colorectal cancers and advanced adenomas are collectively referred to as advanced colorectal neoplasms. Receiver-operating characteristic curve analysis was used to determine thesignificant predictive maximum standardized uptake value (SUVmax) cutoff value for advanced colorectal neoplasms and cancer. RESULTS: Ninety-five colorectal lesions matched the site of incidental focal colorectal 18 F-FDG uptake on PET/CT and 146 did not. Colonoscopy showed advanced colorectal neoplasms corresponding to the site of 18 F-FDG uptake in 49 of the 95 (51.5%) lesions with incidental uptake. Of the lesions without incidental uptake, only 6 of 146 (4.1%) had advanced colorectal neoplasms on colonoscopy, indicating a statistically significant difference between the two groups (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of incidental focal 18 F-FDG uptake in identifying advanced colorectal neoplasms were 89.1%, 75.3%, 51.6%, 95.9%, and 78.4%, respectively. In detecting only CRC, these values were 89.2%, 69.6%, 34.7%, 97.3%, and 72.6%, respectively. The significant SUVmax cutoff value for advanced colorectal neoplasms (area under the curve 0.755, P < 0.001) was 4.35, with a sensitivity, specificity, PPV, NPV, and accuracy of 75.5%, 65.2%, 69.8%, 71.4% and 70.5%, respectively. For CRC, 5.05 was the significant SUVmax cutoff value (area under the curve 0.817, P < 0.001), with a sensitivity, specificity, PPV, NPV, and accuracy of 84.8%, 71.0%, 80.9%, 89.8%, and 75.8%, respectively. CONCLUSION: The presence of incidental focal colorectal 18 F-FDG uptake on PET/CT with a SUVmax ≥ 4.35 increases the likelihood of an advanced colorectal neoplasm.

Tumor characteristics of ductal carcinoma in situ of breast visualized on [F-18] fluorodeoxyglucose-positron emission tomography/computed tomography: Results from a retrospective study

AIM To clarify clinicopathological features of ductal carcinoma in situ(DCIS) visualized on [F-18] fluorodeoxyglucosepositron emission tomography/computed tomography(FDG-PET/CT).METHODS This study retrospectively reviewed 52 consecutive tumors in 50 patients with pathologically proven pure DCIS who underwent [F-18] FDG-PET/CT before surgery. [F-18] FDG-PET/CT was performed after biopsy in all patients. The mean interval from biopsy to [F-18] FDGPET/CT was 29.2 d. [F-18] FDG uptake by visual analysis and maximum standardized uptake value(SUVmax) was compared with clinicopathological characteristics.RESULTS[F-18] FDG uptake was visualized in 28 lesions(53.8%) and the mean and standard deviation of SUVmax was 1.63 and 0.90. On univariate analysis, visual analysis and the SUVmax were associated with symptomatic presentation(P = 0.012 and 0.002, respectively), palpability(P = 0.030 and 0.024, respectively), use of core-needle biopsy(CNB)(P = 0.023 and 0.012, respectively), ultrasound-guided biopsy(P = 0.040 and 0.006, respectively), enhancing lesion ≥ 20 mm on magnetic resonance imaging(MRI)(P = 0.001 and 0.010, respectively), tumor size ≥ 20 mm on histopathology(P = 0.002 and 0.008, respectively). However, [F-18] FDG uptake parameters were not significantly associated with age, presence of calcification on mammography, mass formation on MRI, presence of comedo necrosis, hormone status(estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2), and nuclear grade. The factors significantly associated with visual analysis and SUVmax were symptomatic presentation(P = 0.019 and 0.001, respectively), use of CNB(P = 0.001 and 0.031, respectively), and enhancing lesion ≥ 20 mm on MRI(P = 0.001 and 0.049, respectively) on multivariate analysis.CONCLUSION Although DCIS of breast is generally non-avid tumor, symptomatic and large tumors(≥ 20 mm) tend to be visualized on [F-18] FDG-PET/CT.

Multi-slice spiral computed tomography in diagnosing unstable pelvic fractures in elderly and effect of less invasive stabilization

BACKGROUND Older people are more likely to experience pelvic fractures than younger people.Multi-slice spiral computed tomography(CT)uses three-dimensional(3D)reconstruction technology to generate 3D images that can clearly demonstrate the 3D space of fractures and detect fractures at a higher rate.AIM To investigate the clinical value of multi-slice spiral CT 3D reconstruction in the diagnosis of unstable pelvic fractures in the elderly as well as the effect of less invasive stabilization.METHODS A total of 86 patients with unstable pelvic fractures treated between March 2016 and March 2019 underwent femoral supracondylar bone traction before surgery.Pelvic radiography and multi-row spiral CT were performed successively once the patient’s vital signs and hemodynamic indices were stable.Secondary processing of the original data was performed to obtain 3D reconstruction images and determine the vertical displacement of the pelvis.After basic or complete reduction,minimally invasive internal fixation using hollow lag screws was performed.The detection rates of fracture location and classification by X-ray and CT reconstruction were compared.Patients were divided into two groups according to the presence or absence of preoperative 3D reconstruction to compare postoperative reduction,wound healing time,fracture healing time,hospitalization time,visual analog scale(VAS)score,poor internal fixation,and functional recovery.RESULTS The diagnostic coincidence rates of X-rays for pubic symphysis,ilium wing,sacroiliac periarticular,and sacral fractures were lower than those of CT reconstruction.The coincidence rate of CT reconstruction in the clinical classification of pelvic fractures was 100%,whereas 11 cases were misdiagnosed by X-ray;the total coincidence rate was 87.21%.The total excellent and good rates of postoperative reduction were significantly higher in the study group than in the control group(P<0.05).The wound healing,fracture healing,and hospitalization times were significantly shorter in the study group than in the control group(P<0.05).The VAS scores decreased in both groups postoperatively and were lower in the study group than in the control group(P<0.05).The total incidence of poor postoperative internal fixation was significantly lower in the study group than in the control group(P<0.05).The overall rate of postoperative functional recovery was significantly higher in the study group than in the control group(P<0.05).CONCLUSION Multi-slice spiral CT has high guiding significance for the diagnosis,classification,and treatment of unstable pelvic fractures in the elderly.Preoperative 3D reconstruction can effectively shorten the operation time and promote fracture healing,while minimally invasive internal fixation can effectively reduce pain and promote functional recovery of fracture sites,making it worthy of clinical application.

Multi-slice spiral computed tomography in differential diagnosis of gastric stromal tumors and benign gastric polyps,and gastric stromal tumor risk stratification assessment

BACKGROUND The biological characteristics of gastric stromal tumors are complex,and their incidence has increased in recent years.Gastric stromal tumors(GST)have potential malignant tendencies,and the probability of transformation into malignant tumors is as high as 20%-30%.AIM To investigate the value of multi-slice spiral computed tomography(MSCT)in the differential diagnosis of GST and benign gastric polyps,and GST risk stratification assessment.METHODS We included 64 patients with GST(GST group)and 60 with benign gastric polyps(control group),confirmed by pathological examination after surgery in PLA General Hospital,from January 2016 to June 2021.The differences in the MSCT imaging characteristic parameters and enhanced CT values between the two groups before surgery were compared.According to the National Institutes of Health’s standard,GST is divided into low-and high-risk groups for MSCT imaging characteristic parameters and enhanced CT values.RESULTS The incidences of extraluminal growth,blurred boundaries,and ulceration in the GST group were significantly higher than those in the control group(P<0.05).The CT values and enhanced peak CT values in the arterial phase in the CST group were higher than those in the control group(P<0.05).The MSCT differential diagnosis of GST and gastric polyp sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and areas under the curve(AUCs)were 73.44%,83.33%,26.56%,16.67%,0.784,respectively.The receiver operating characteristic curves were plotted with the arterial CT value and enhanced peak CT value,with a statistical difference.The results showed that the sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of arterial CT in the differential diagnosis of GST and gastric polyps were 80.18%,62.20%,19.82%,37.80%,and 0.710,respectively.The sensitivity,specificity,misdiagnosis rate,missed diagnosis rate,and AUC value of the enhanced peak CT value in the differential diagnosis of GST and gastric polyps were 67.63%,60.40%,32.37%,39.60%,and 0.710,respectively.The incidence of blurred lesion boundaries and ulceration in the high-risk group was significantly higher than that in the low-risk group(P<0.05).The arterial phase and enhanced peak CT values in the high-risk group were significantly higher than those in the low-risk group(P<0.05).CONCLUSION Presurgical MSCT examination has important value in the differential diagnosis of GST and gastric benign polyps and can effectively evaluate the risk grade of GST patients.

Nomogram using F-18 fluorodeoxyglucose positron emission tomography/computed tomography for preoperative prediction of lymph node metastasis in gastric cancer

BACKGROUND Lymph node(LN)metastasis is an important prognostic factor in patients with gastric cancer(GC).However,the evaluation of LN metastasis status in the preoperative setting is not accurate.Therefore,precise preoperative prediction of LN metastasis status is crucial for optimal treatment in patients with GC.AIM To develop a preoperative nomogram for LN metastasis using F-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)and preoperative laboratory test findings in GC.METHODS In this study,the data of 566 GC patients who underwent preoperative F-18 FDG PET/CT and subsequent surgical resection were analyzed.The LN metastasis prediction model was developed in the training cohort and validated in the internal validation cohort.Routine preoperative laboratory tests,including albumin and carbohydrate antigen(CA)19-9 were performed in all patients.Univariate and multivariable logistic regression was performed to validate the preoperative predictive indicators for LN metastasis.RESULTS Of the 566 patients,232(41%)had confirmed histopathologic LN metastasis.Univariate logistic regression revealed that the tumor location,blood hemoglobin,serum albumin levels,neutrophil to lymphocyte ratio,platelet to lymphocyte ratio,CA 19-9,maximum standardized uptake value(SUVmax)of the primary tumor(T_SUVmax),and SUVmax of LN(N_SUVmax)were significantly associated with LN metastasis.In multivariate analysis,T_SUVmax(OR=1.08;95%CI:1.02–1.15;P=0.011)and N_SUVmax(OR=1.49;95%CI:1.19–1.97;P=0.002)were found to be significant predictive factors for LNmetastasis.The LN metastasis prediction model using T_SUVmax,N_SUVmax,serum albumin,and CA 19-9 yielded an area under the curve(AUC)of 0.733(95%CI:0.683–0.784,P=0.025)in the training cohort and AUC of 0.756(95%CI:0.678–0.833,P<0.001)in the test cohort.CONCLUSION T_SUVmax and N_SUVmax measured by preoperative F-18 FDG PET/CT are independent predictive factors for LN metastasis in GC.

Positron emission tomography/computed tomography with ^(18)F-fluorodeoxyglucose identifies tumor growth or thrombosis in the portal vein with hepatocellular carcinoma

Patients suffering from hepatocellular carcinoma (HCC) with tumor thrombus in the portal vein generally have a poor prognosis. Portal vein tumor thrombus must be distinguished from portal vein blood thrombus, and this identification plays a very important role in management of HCC. Conventional imaging modalities have limitations in discrimination of portal vein tumor thrombus. The application of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for discrimination between tumor extension and blood thrombus has been reported in few cases of HCC, while portal tumor thrombosis and portal vein clot identified by 18F-FDG PET/CT in HCC patients has not been reported so far. We present two HCC cases, one with portal vein tumor thrombus and one thrombosis who were identified with 18F-FDG PET/CT. This report illustrates the complimentary value of combining the morphological and functional imaging in achieving a correct diagnosis in such clinical situations.

Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIM To compare the value of contrast-enhanced abdominal computed tomography(CT) and fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT) for detecting gastric carcinoma recurrence.METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group(P < 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Fortyfour patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities(P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT(96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT(98% vs 80%, P = 0.035).CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.