Common bile duct stones on multidetector computed tomography:Attenuation patterns and detectability

AIM:To investigate the attenuation patterns and detectability of common bile duct(CBD) stones by multidetector computed tomography(MDCT).METHODS:Between March 2010 and February 2012,191 patients with suspicion of CBD stones undergoing both MDCT and endoscopic retrograde cholangiopancreatography(ERCP) were enrolled and reviewed retrospectively.The attenuation patterns of CBD stones on MDCT were classified as heavily calcified,radiopaque,less radiopaque,or undetectable.The association between the attenuation patterns of CBD stones on MDCT and stone type consisting of pure cholesterol,mixed cholesterol,brown pigment,and black pigment and the factors related to the detectability of CBD stones by MDCT were evaluated.RESULTS:MDCT showed CBD stones in 111 of 130 patients in whom the CBD stones were demonstrated by ERCP with 85.4% sensitivity.The attenuation patterns of CBD stones on MDCT were heavily calcified 34(26%),radiopaque 31(24%),less radiopaque 46(35%),and undetectable 19(15%).The radiopacity of CBD stones differed significantly according to stone type(P < 0.001).From the receiver operating characteristic curve,stone size was useful for the determination of CBD stone by MDCT(area under curve 0.779,P < 0.001) and appropriate cut-off stone size on MDCT was 5 mm.The factors related to detectability of CBD stones on MDCT were age,stone type,and stone size on multivariate analysis(P < 0.05).CONCLUSION:The radiopacity of CBD stones on MDCT differed according to stone type.Stone type and stone size were related to the detectability by MDCT,and appropriate cut-off stone size was 5 mm.

Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

Renal cell carcinoma(RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography(CT) is considered the examination of choice for thedetection and staging of RCC. Multidetector CT(MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and threedimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment.

Value of two-phase dynamic multidetector computed tomography in differential diagnosis of post-inflammatory strictures from esophageal cancer

AIM: To characterize the computed tomography(CT) findings in patients with post-inflammatory esophageal strictures(corrosive and peptic) and reveal the optimal scanning phase protocols for distinguishing postinflammatory esophageal stricture and esophageal cancer.METHODS: Sixty-five patients with esophageal strictures of different etiology were included in this study: 24 patients with 27 histopathologically confirmed corrosive strictures, 10 patients with 12 peptic strictures and 31 patients with esophageal cancer were evaluated with a two-phase dynamic contrast-enhanced MDCT. Arterial and venous phases at 10 and 35 s after the attenuation of 200 HU were obtained at the descending aorta, with a delayed phase at 6-8 min after the start of injection of contrast media. For qualitative analysis, CT scans of benign strictures were reviewed for the presence/absence of the following features: "target sign", luminal mass, homogeneity of contrast medium uptake, concentric wall thickening, conically shapedsuprastenotic dilatation, smooth boundaries of stenosis and smooth mucous membrane at the transition to stenosis, which were compared with a control group of 31 patients who had esophageal cancer. The quantitative analysis included densitometric parameter acquisition using regions-of-interest measurement of the zone of stenosis and normal esophageal wall and the difference between those measurements(ΔCT) at all phases of bolus contrast enhancement. Esophageal wall thickening, length of esophageal wall thickening and size of the regional lymph nodes were also evaluated. RESULTS: The presence of a concentric esophageal wall, conically shaped suprastenotic dilatation, smooth upper and lower boundaries, "target sign" and smooth mucous membrane at the transition to stenosis were suggestive of a benign cause, with sensitivities of 92.31%, 87.17%, 94.87%, 76.92% and 82.05%, respectively, and specificities of 70.96%, 89.66%, 80.65%, 96.77% and 93.55%, respectively. The features that were most suggestive of a malignant cause were eccentric esophageal wall thickening, tuberous upper and lower boundaries of stenosis, absence of mucous membrane visualization, rupture of the mucous membrane at the upper boundary of stenosis, cup-shaped suprastenotic dilatation, luminal mass and enlarged regional lymph nodes with specificities of 92.31% 94.87%, 67.86%, 100%, 97.44%, 94.87% and 82.86%, respectively and sensitivities of 70.97%, 80.65%, 96.77%, 80.65%, 54.84%, 87.10% and 60%, respectively. The highest tumor attenuation occurred in the arterial phase(mean attenuation 74.13 ± 17.42 HU), and the mean attenuation difference between the tumor and the normal esophageal wall(mean ΔCT) in the arterial phase was 23.86 ± 19.31 HU. Here, 11.5 HU of ΔCT in the arterial phase was the cut-off value used to differentiate esophageal cancer from post-inflammatory stricture(P = 0.000). The highest attenuation of postinflammatory strictures occurred in the delayed phase(mean attenuation 71.66 ± 14.28 HU), and the mean ΔCT in delayed phase was 34.03 ± 15.94 HU. Here, 18.5 HU of ΔCT in delayed phase was the cut-off value used to differentiate post-inflammatory stricture from esophageal cancer(P < 0.0001).CONCLUSION: The described imaging findings reveal high diagnostic significance in the differentiation of benign strictures from esophageal cancer.

Optimized protocol of multiple post-processing techniques improves diagnostic accuracy of multidetector computed tomography in assessment of small bowel obstruction compared with conventional axial and coronal reformations

BACKGROUND Axial and coronal reformations have been a widely used image post-processing protocol for the ordinary multidetector computed tomography(MDCT)examination of patients with small bowel obstruction(SBO) or other abdominal diseases. The diagnostic accuracy of MDCT for assessing SBO is expected to be further improved through the use of multiple post-processing techniques.AIM To systemically evaluate the diagnostic accuracy and efficiency of an optimized protocol using multiple post-processing techniques for MDCT assessment of SBO and secondary bowel ischemia.METHODS This retrospective cross-sectional study included 106 patients with clinically suspected SBO. Two readers applied three protocols to image post-processing and interpretation of patients' MDCT volume data. We compared the three protocols based on time spent, number of images, diagnostic self-confidence,agreement, detection rate, and accuracy of detection of SBO and secondary bowel ischemia.RESULTS Protocol 2 resulted in more time spent and number of images than protocols 1 and 3(P < 0.01), but the results of the two readers using the same protocol were not different(P > 0.05). Using protocol 3, both readers added multiple postprocessing techniques at frequencies of 29.2% and 34.9%, respectively, for obstruction cause, and 32.1% and 30.2%, respectively, for secondary bowel ischemia. Protocols 2 and 3 had higher total detection rates of obstruction cause and secondary bowel ischemia than protocol 1(P < 0.01), but no difference was detected between protocols 2 and 3(P > 0.05). The accuracy, sensitivity,specificity, positive predictive value and negative predictive value of protocols 2 and 3 were superior to those of protocol 1 for evaluating obstruction cause and secondary bowel ischemia.CONCLUSION Our optimized protocol of multiple post-processing techniques can both guarantee efficiency and improve diagnostic accuracy of MDCT for assessing SBO and secondary bowel ischemia.

Evaluation of human epidermal growth factor receptor 2 status of breast cancer using preoperative multidetector computed tomography with deep learning and handcrafted radiomics features

Objective:To evaluate the human epidermal growth factor receptor 2(HER2)status in patients with breast cancer using multidetector computed tomography(MDCT)-based handcrafted and deep radiomics features.Methods:This retrospective study enrolled 339 female patients(primary cohort,n=177;validation cohort,n=162)with pathologically confirmed invasive breast cancer.Handcrafted and deep radiomics features were extracted from the MDCT images during the arterial phase.After the feature selection procedures,handcrafted and deep radiomics signatures and the combined model were built using multivariate logistic regression analysis.Performance was assessed by measures of discrimination,calibration,and clinical usefulness in the primary cohort and validated in the validation cohort.Results:The handcrafted radiomics signature had a discriminative ability with a C-index of 0.739[95%confidence interval(95%CI):0.661-0.818]in the primary cohort and 0.695(95%CI:0.609-0.781)in the validation cohort.The deep radiomics signature also had a discriminative ability with a C-index of 0.760(95%CI:0.690-0.831)in the primary cohort and 0.777(95%CI:0.696-0.857)in the validation cohort.The combined model,which incorporated both the handcrafted and deep radiomics signatures,showed good discriminative ability with a C-index of 0.829(95%CI:0.767-0.890)in the primary cohort and 0.809(95%CI:0.740-0.879)in the validation cohort.Conclusions:Handcrafted and deep radiomics features from MDCT images were associated with HER2 status in patients with breast cancer.Thus,these features could provide complementary aid for the radiological evaluation of HER2 status in breast cancer.

Multidetector computed tomography features of pancreatic metastases from leiomyosarcoma: Experience at a tertiary cancer center

AIM: To describe the multidetector computed tomography features of pancreatic metastasis from leiomyosarcoma(LMS).METHODS: Between January 1995 and December 2012, 13 consecutive patients(11 women, 2 men; mean age of 57 years; range, 38-78 years) with pancreatic metastases from LMS were included in our study. Imaging features including location, number, largest dimension, tumor attenuation and enhancement characteristics, presence of necrosis, pancreatic ductal dilatation, common bile duct(CBD) dilatation, presence of pancreatitis, and atrophy were documented.RESULTS: The most common site of origin of the pancreatic metastases from LMS was uterus(38.5%), followed by retroperitoneum(30.8%) and extremity(23.1%). None of the patients in our study had pancreas as the first site of metastasis. All patients developed pancreatic metastases at a median interval of 24 mo. Pancreatic metastases from LMS were solitary in 8/13 patients and multiple in 5/13 patients, had no predilection for any part of the pancreas, were hypovascular on arterial phase in 10/13 patients and associated with pancreatic duct dilatation in 3/13 patients. None had CBD dilatation. None of the pancreatic metastases in LMS cohort caused pancreatitis, and atrophy. Median duration of follow-up was 19 mo for LMS cohort during which two patients underwent resection of metastasis(median survival 45 mo) while the remaining underwent systemic therapy(median survival 13 mo).CONCLUSION: Pancreatic metastases from LMS are often solitary and hypovascular masses and less commonly associated with pancreatic ductal dilatation, CBD dilatation, pancreatitis or pancreatic atrophy. Surgical resection of solitary LMS pancreatic metastasis can be considered due to the long survival of these patients.

Comparison of pancreatic acinar cell carcinoma and adenocarcinoma using multidetector-row computed tomography

AIM:To distinguish acinar cell carcinoma(ACC)from pancreatic adenocarcinoma(AC)by comparing their computed tomography findings.METHODS:Patients with ACC and AC were identified on the basis of results obtained using surgically resected pancreatectomy specimens.The preoperative computer tomographic images of 6 acinar cell carcinoma patients and 67 pancreatic adenocarcinoma patients in 4 phases(non-contrast,arterial,portal venous,and delayed phase)were compared.The scan delay times were 40,70,and 120 s for each contrast-enhanced phase.The visual pattern,tomographic attenuation value,and time attenuation curve were assessed and compared between AC and ACC cases using the 2test,Wilcoxon signed-rank test,and Mann Whitney U test.RESULTS:The adenocarcinomas tended to be hypodense in all 4 phases.The acinar cell carcinomas also tended to be hypodense in the 3 contrast-enhancedphases,although their computed tomographic attenuation values were higher.Further,5 of the 6 acinar cell carcinomas(83%)were isodense in the non-contrast phase.The time attenuation curve of the adenocarcinomas showed a gradual increase through the 4 phases,and all adenocarcinomas showed peak enhancement during the delayed phase.The time attenuation curve of the acinar cell carcinomas showed peak enhancement during the portal venous phase in 4 cases and during the arterial phase in 2 cases.None of the 6 acinar cell carcinomas showed peak enhancement during the delayed phase.CONCLUSION:The tumor density in the non-contrast phase and time attenuation curve pattern clearly differ between acinar cell carcinomas and adenocarcinomas,and multidetector-row computed tomography can thus distinguish these tumors.

Clinical impact of multidetector computed tomography before double-balloon enteroscopy for obscure gastrointestinal bleeding

AIM:To evaluate the clinical impact of multidetector computed tomography (MDCT) before double-balloon endoscopy (DBE) for patients with obscure gastrointestinal bleeding (OGIB).METHODS:A retrospective analysis of prospectively collected cases with DBE and MDCT for overt OGIB was conducted from April 2004 to April 2010 at Changhua Christian Hospital.We evaluated the clinical impact of MDCT on the subsequent DBE examinations and the diagnostic yields of both MDCT and DBE respectively.RESULTS:From April 2004 to April 2010,a total of 75 patients underwent DBE for overt OGIB.Thirty one cases received MDCT followed by DBE for OGIB.The overall diagnostic yields of DBE and MDCT was 93.5% and 45.2%.The MDCT had a high diagnostic yield of tumor vs non-tumor etiology of OGIB (85.7% vs 33.3%,P=0.014).Additionally,the choice of initial route of DBE was correct in those with a positive MDCT vs negative MDCT (100% vs 52.9%,P=0.003).CONCLUSION:This study suggests MDCT as a triage tool may identify patients who will benefit from DBE and aid the endoscopist in choosing the most efficient route.

Role of multidetector computed tomography in patients with acute infectious colitis

BACKGROUND The role of multidetector computed tomography(MDCT)in patients with acute infectious colitis is still unclear.AIM To examine the usefulness of MDCT in distinguishing the etiology of acute infectious colitis.METHODS Overall,244 patients who met the criteria for acute infectious colitis and visited the Hospital from February 2015 to 2018 were retrospectively enrolled and divided into two groups(bacterial:204,viral:40)according to causes of acute colitis,based on stool PCR.Eleven MDCT parameters,including wall thickening,submucosal edema,mucosal enhancement,serosa involvement,empty colon sign,small bowel involvement,comb sign,continuous distribution,accordion sign,mucosal thickening,and lymph node enlargement,were constructed in a blinded fashion.RESULTS MDCT parameters of wall thickening(OR:13.60;95%CI:5.80–31.88;P<0.001),submucosal edema(OR:36.08;95%CI:13.54–96.13;P<0.001),mucosal enhancement(OR:22.55;95%CI:9.28–54.81;P<0.001),serosal involvement(OR:14.50;95%CI:3.33–63.23;P<0.001),empty colon sign(OR:6.68;95%CI: 2.44–18.32;P < 0.001), continuous distribution (OR: 24.09;95%CI: 9.38–61.90;P < 0.001), accordionsign (OR: 9.02;95%CI: 1.12–72.35;P = 0.038), mucosal thickening (OR: 46.41;95%CI: 10.38–207.51;P< 0.001), and lymph node enlargement (OR: 4.39;95%CI: 1.22–15.72;P = 0.023) were significantlyassociated with bacterial colitis. At least one positive finding in four CT outcomes (submucosaledema, mucosal enhancement, continuous distribution, mucosal thickening) in summer showed ahigh probability of bacterial colitis (sensitivity, 41.67;specificity, 92.50;OR: 24.95).CONCLUSIONMDCT provides many clues that can be useful in suggesting a specific etiology of acute infectiouscolitis.

Role of clinical data and multidetector computed tomography findings in acute superior mesenteric artery embolism

BACKGROUND Superior mesenteric artery embolism(SMAE)has acute onset and fast progression,which seriously threatens the life of patients.Multidetector computed tomography(MDCT)is one of the most important diagnostic methods for SMAE,which plays an important role in the diagnosis and prognosis of SMAE.AIM To evaluate the value of combined clinical data and MDCT findings in the diagnosis of acute SMAE and predict the risk factors for SMAE-related death.METHODS Data from 53 SMAE patients who received abdominal MDCT multi-phase enhancement and superior mesenteric artery digital subtraction angiography examinations were collected.Univariate cox regression and multivariate cox model were used to analyze the correlation between death risk and clinical and computed tomography features in SMAE patients.RESULTS Univariate Cox regression model showed that intestinal wall thinning,intestinal wall pneumatosis,blood lactate>2.1 mmol/L and blood pH<7.35 increased the risk of death in patients with SMAE.After adjusting for age,sex,embolic involvement length and embolic distribution region,multivariate Cox regression model I showed that blood lactate>2.1 mmol/L(HR=5.26,95%CI:1.04-26.69,P=0.045)and intestinal wall thinning(HR=9.40,95%CI:1.05-83.46,P=0.044)were significantly increases the risk of death in patients with SMAE.CONCLUSION For patients with SAME,increased blood lactate and intestinal wall thinning are the risk factors for death;hence,close monitoring may reduce the mortality rate.Clinical observation combined with MDCT signs can significantly improve SMAE diagnosis.

Role of multidetector computed tomography angiography in nonvariceal upper gastrointestinal bleeding:A comprehensive review

Non-variceal upper gastrointestinal bleeding(NVUGIB)is a common gastroenterological emergency associated with significant morbidity and mortality.Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment,with computed tomography traditionally playing a limited role in the diagnosis of acute NVUGIB.Following the introduction of multidetector computed tomography(MDCT),this modality is emerging as a promising tool in the diagnosis of NVUGIB.However,to date,evidence concerning the role of MDCT in the NVUGIB diagnosis is still lacking.The aim of our study was to review the current evidence concerning the role of MDCT in the diagnosis of acute NVUGIB.

Effectiveness of Multidetector Computed Tomography in Prosthetic Valve Endocarditis

Background: Redo aortic valve replacement for prosthetic valve endocarditis is a challenge for surgeons. Echocardiography is occasionally not an effective modality for the detection of infectious signs in prosthetic valve endocarditis. Case presentation: Herein, we report the case of a patient whose prosthetic valve endocarditis was detected by multidetector computed tomography and who successfully underwent redo aortic valve replacement. Preoperative echocardiography revealed no remarkable findings related to endocarditis such as perivalvular leakage or vegetation;however, multidetector computed tomography revealed a thickened right coronary cusp. Intraoperatively, the right coronary cusp was confirmed to be covered with thick infected tissue. The pathological findings revealed broad destruction due to infection of the right coronary cusp. Conclusion: Multidetector computed tomography was useful in detecting infectious signs in prosthetic valves.

Acquired renal arteriovenous malformation:the diagnostic value of three-dimensional multidetector-row computed tomography

Objective To evaluate the diagnostic value of three-dimensional multidetector-row computed tomography(MDCT) in detecting acquired renal arteriovenous malformation(RAVM) and to compare its performance with that of ultrasonography and digital subtraction angiography(DSA). Methods The institutional review board approved this retrospective study and written informed consent was obtained from all patients before examination. All 14 patients with acquired RAVM underwent MDCT, including cortical and medullary phase enhancement angiography and three-dimensional(3D) reconstruction. Five and nine patients were further examined and their diagnoses confirmed by DSA and surgery, respectively. The MDCT images, including 3D reconstructions, were analyzed for RAVM independently and in consensus by two observers using a workstation.Results Among the 14 patients with acquired RAVM, 12 with maximum lesion diameter ≥ 10 mm, and one with a maximum lesion diameter between 5 and 10 mm, were correctly diagnosed with MDCT angiography. Among these patients, four diagnoses were confirmed by DSA. One patient with a lesion 5–10 mm in diameter was misdiagnosed with a renal aneurysm by MDCT angiography. The other one with the maximum diameter of the lesion between 5 mm and 10 mm was misdiagnosed as renal aneurysm with MDCT angiography, which was diagnosed as renal arteriovenous malformation with DSA. Among 14 lesions in 14 patients, eight and six originated in the left and right kidney, respectively.Conclusion MDCT angiography can accurately diagnose RAVM and improve our understanding of the disease, which will allow clinicians to provide better care.

Computed tomography vs liver stiffness measurement and magnetic resonance imaging in evaluating esophageal varices in cirrhotic patients:A systematic review and meta-analysis

BACKGROUND Computed tomography(CT),liver stiffness measurement(LSM),and magnetic resonance imaging(MRI)are non-invasive diagnostic methods for esophageal varices(EV)and for the prediction of high-bleeding-risk EV(HREV)in cirrhotic patients.However,the clinical use of these methods is controversial.AIM To evaluate the accuracy of LSM,CT,and MRI in diagnosing EV and predicting HREV in cirrhotic patients.METHODS We performed literature searches in multiple databases,including Pub Med,Embase,Cochrane,CNKI,and Wanfang databases,for articles that evaluated the accuracy of LSM,CT,and MRI as candidates for the diagnosis of EV and prediction of HREV in cirrhotic patients.Summary sensitivity and specificity,positive likelihood ratio and negative likelihood ratio,diagnostic odds ratio,and the areas under the summary receiver operating characteristic curves were analyzed.The quality of the articles was assessed using the quality assessment of diagnostic accuracy studies-2 tool.Heterogeneity was examined by Q-statistic test and I2 index,and sources of heterogeneity were explored using metaregression and subgroup analysis.Publication bias was evaluated using Deek’s funnel plot.All statistical analyses were conducted using Stata12.0,Meta Disc1.4,and Rev Man5.3.RESULTS Overall,18,17,and 7 relevant articles on the accuracy of LSM,CT,and MRI in evaluating EV and HREV were retrieved.A significant heterogeneity was observed in all analyses(P<0.05).The areas under the summary receiver operating characteristic curves of LSM,CT,and MRI in diagnosing EV and predicting HREV were 0.86(95%confidence interval[CI]:0.83-0.89),0.91(95%CI:0.88-0.93),and 0.86(95%CI:0.83-0.89),and 0.85(95%CI:0.81-0.88),0.94(95%CI:0.91-0.96),and 0.83(95%CI:0.79-0.86),respectively,with sensitivities of 0.84(95%CI:0.78-0.89),0.91(95%CI:0.87-0.94),and 0.81(95%CI:0.76-0.86),and 0.81(95%CI:0.75-0.86),0.88(95%CI:0.82-0.92),and 0.80(95%CI:0.72-0.86),and specificities of 0.71(95%CI:0.60-0.80),0.75(95%CI:0.68-0.82),and 0.82(95%CI:0.70-0.89),and 0.73(95%CI:0.66-0.80),0.87(95%CI:0.81-0.92),and 0.72(95%CI:0.62-0.80),respectively.The corresponding positive likelihood ratios were 2.91,3.67,and 4.44,and 3.04,6.90,and2.83;the negative likelihood ratios were 0.22,0.12,and 0.23,and 0.26,0.14,and 0.28;the diagnostic odds ratios were 13.01,30.98,and 19.58,and 11.93,49.99,and 10.00.CT scanner is the source of heterogeneity.There was no significant difference in diagnostic threshold effects(P>0.05)or publication bias(P>0.05).CONCLUSION Based on the meta-analysis of observational studies,it is suggested that CT imaging,a non-invasive diagnostic method,is the best choice for the diagnosis of EV and prediction of HREV in cirrhotic patients compared with LSM and MRI.

Predictive value of multi-detector computed tomography for accurate diagnosis of serous cystadenoma:Radiologic-pathologic correlation

AIM:To identify multi-detector computed tomography(MDCT) features most predictive of serous cystadenomas(SCAs),correlating with histopathology,and to study the impact of cyst size and MDCT technique on reader performance.METHODS:The MDCT scans of 164 patients with surgically verified pancreatic cystic lesions were reviewed by two readers to study the predictive value of various morphological features for establishing a diagnosis of SCAs.Accuracy in lesion characterization and reader conf idence were correlated with lesion size(≤3cm or≥3cm) and scanning protocols(dedicated vs routine).RESULTS:28/164 cysts(mean size,39 mm;range,8-92mm) were diagnosed as SCA on pathology.The MDCT features predictive of diagnosis of SCA were microcystic appearance(22/28,78.6%),surface lobulations(25/28,89.3%) and central scar(9/28,32.4%).Stepwise logistic regression analysis showed that only microcystic appearance was signifi cant for CT diagnosis of SCA(P=0.0001).The sensitivity,specificity and PPV of central scar and of combined microcystic appearance and lobulations were 32.4%/100%/100% and 68%/100%/100%,respectively.The reader confidence was higher for lesions>3cm(P=0.02) and for MDCT scans performed using thin collimation(1.25-2.5mm) compared to routine 5 mm collimation exams(P>0.05).CONCLUSION:Central scar on MDCT is diagnostic of SCA but is seen in only one third of SCAs.Microcystic morphology is the most significant CT feature in diagnosis of SCA.A combination of microcystic appearance and surface lobulations offers accuracy comparable to central scar with higher sensitivity.

Gd-EOB-DTPA-enhanced magnetic resonance imaging features of hepatic hemangioma compared with enhanced computed tomography

AIM:To clarify features of hepatic hemangiomas on gadolinium-ethoxybenzyl-diethylenetriaminpentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared with enhanced computed tomography (CT). METHODS:Twenty-six patients with 61 hepatic hem- angiomas who underwent both Gd-EOB-DTPA-enhanced MRI and enhanced CT were retrospectively reviewed. Hemangioma appearances (presence of peripheral nodular enhancement, central nodular enhancement, diffuse homogenous enhancement, and arterioportal shunt during the arterial phase, fill-in enhancement during the portal venous phase, and prolonged enhancement during the equilibrium phase) on Gd-EOB-DTPA-enhanced MRI and enhanced CT were evaluated.The degree of contrast enhancement at the enhancing portion within the hemangioma was visually assessed using a five-point scale during each phase. For quantitative analysis, the tumor-muscle signal intensity ratio (SIR), the liver-muscle SIR, and the attenuation value of the tumor and liver parenchyma were calculated. The McNemar test and the Wilcoxon's signed rank test were used to assess the significance of differences in the appearances of hemangiomas and in the visual grade of tumor contrast enhancement between Gd-EOB-DTPA-enhanced MRI and enhanced CT. RESULTS:There was no significant difference between Gd-EOB-DTPA-enhanced MRI and enhanced CT in the presence of peripheral nodular enhancement (85% vs 82%), central nodular enhancement (3% vs 3%), diffuse enhancement (11% vs 16%), or arterioportal shunt (23% vs 34%) during arterial phase, or fill-in enhancement (79% vs 80%) during portal venous phase. Prolonged enhancement during equilibrium phase was observed less frequently on Gd-EOB-DTPA-enhanced MRI than on enhanced CT (52% vs 100%, P < 0.001). On visual inspection, there was significantly less contrast enhancement of the enhancing portion on Gd-EOB-DTPA-enhanced MRI than on enhanced CT during the arterial (3.94 ± 0.98 vs 4.57 ± 0.64, respectively, P < 0.001), portal venous (3.72 ± 0.82 vs 4.36 ± 0.53, respectively, P < 0.001), and equilibrium phases (2.01 ± 0.95 vs 4.04 ± 0.51, respectively, P < 0.001). In the quantitative analysis, the tumor-muscle SIR and the liver-muscle SIR observed with Gd-EOB-DTPA-enhanced MRI were 0.80 ± 0.24 and 1.28 ± 0.33 precontrast, 1.92 ± 0.58 and 1.57 ± 0.55 during the arterial phase, 1.87 ± 0.44 and 1.73 ± 0.39 during the portal venous phase, 1.63 ± 0.41 and 1.78 ± 0.39 during the equilibrium phase, and 1.10 ± 0.43 and 1.92 ± 0.50 during the hepatobiliary phase, respectively. The attenuation values in the tumor and liver parenchyma observed with enhanced CT were 40.60 ± 8.78 and 53.78 ± 7.37 precontrast, 172.66 ± 73.89 and 92.76 ± 17.92 during the arterial phase, 152.76 ± 35.73 and 120.12 ± 18.02 during the portal venous phase, and 108.74 ± 18.70 and 89.04 ± 7.25 during the equilibrium phase, respectively. Hemangiomas demonstrated peak enhancement during the arterial phase, and both the SIR with Gd-EOB-DTPA-enhanced MRI and the attenuation value with enhanced CT decreased with time. The SIR of hemangiomas was lower than that of liver parenchyma during the equilibrium and hepatobiliary phases on Gd-EOB-DTPA-enhanced MRI. However, the attenuation of hemangiomas after contrast injection was higher than that of liver parenchyma during all phases of enhanced CT. CONCLUSION:Prolonged enhancement during the equilibrium phase was observed less frequently on Gd-EOB-DTPA-enhanced MRI than enhanced CT, which may exacerbate differentiating between hemangiomas and malignant tumors.

Computed tomography of Crohn's disease:The role of three dimensional technique

Crohn's disease,a transmural inflammatory bowel disease,remains a difficult entity to diagnose clinically.Over the last decade,multidetector computed tomography(CT) has become the method of choice for noninvasive evaluation of the small bowel,and has proved to be of significant value in the diagnosis of Crohn's disease.Advancements in CT enterography protocol design,three dimensional(3-D) post-processing software,and CT scanner technology have allowed increasing accuracy in diagnosis,and the acquisition of studies at a much lower radiation dose.The cases in this review will illustrate that the use of 3-D technique,proper enterography protocol design,and a detailed understanding of the different manifestations of Crohn's disease are all critical in properly diagnosing the full range of possible complications in Crohn's patients.In particular,CT enterography has proven to be effective in identifying involvement of the small and large bowel(including active inflammation,stigmata of chronic inflammation,and Crohn's-related bowel neoplasia) by Crohn's disease,as well as the extra-enteric manifestations of the disease,including fistulae,sinus tracts,abscesses,and urologic/hepatobiliary/osseous complications.Moreover,the proper use of 3-D technique(including volume rendering and maximum intensity projection) as a routine component of enterography interpretation can play a vital role in improving diagnostic accuracy.

Comparison of computed tomography findings between bacteremic and non-bacteremic acute pyelonephritis due to Escherichia coli

AIM:To identify computed tomography(CT)findings that are associated with the presence of bacteremia in patients with acute pyelonephritis(APN)due to Escherichia coli(E.coli).METHODS:The clinical data and contrast-enhanced CT findings of 128 patients who were diagnosed with APN due to E.coli and showed renal abnormality on contrast-enhanced CT between January 2003 and November 2013 were retrospectively reviewed.The patients were divided into two groups according to the presence of bacteremia:The bacteremia group and the non-bacteremia group.The abnormality on contrast-enhanced CT were categorized into 5 renal and 4 extrarenal CT findings and compared between the two groups using the χ~2 test and multivariate logistic regression.RESULTS:Among the 128 patients,34 patients(26.6%)were classified into the bacteremia group and 94 patients(73.4%)into the non-bacteremia group.There was no statistically significant difference in gender between the two groups(P = 0.09),but the age of thepatients in the bacteremia group was higher than that of the patients in the non-bacteremia group(P < 0.01).Compared to the non-bacteremia group,1 renal CT finding such as urothelial thickening and 3 extrarenal CT findings such as diffuse peritoneal thickening,cystitis and pulmonary congestion were more frequently observed in the bacteremia group with statistical significance.The logistic regression analysis revealed that CT findings,including urothelial thickening,diffuse peritoneal thickening,cystitis and pulmonary congestion were suggested as the predictive CT findings of bacteremic APN.CONCLUSION:On CT,urothelial thickening,diffuse peritoneal thickening,cystitis,and pulmonary congestion are more frequently observed in patients with bacteremic APN due to E.coli.

High-resolution computed tomography findings in humoral primary immunodeficiencies and correlation with pulmonary function tests

AIM To compare high-resolution computed tomography(HRCT) findings between humoral primary immunodeficiencies(hPIDs) subtypes; to correlate these findings to pulmonary function tests(PFTs).METHODS We retrospectively identified 52 consecutive adult patients with hPIDs who underwent 64-row HRCT and PFTs at the time of diagnosis. On a per-patient basis, an experienced radiologist recorded airway abnormalities(bronchiectasis,airway wall thickening, mucus plugging, tree-in-bud, and air-trapping) and parenchymal-interstitial abnormalities(consolidations, ground-glass opacities,linear and/or irregular opacities, nodules, and bullae/cysts) found on HRCT.The chi-square test was performed to compare the prevalence of each abnormality among patients with different subtypes of hPIDs. Overall logistic regression analysis was performed to assess whether HRCT findings predicted obstructive and/or restrictive PFTs results(absent-to-mild vs moderate-tosevere).RESULTS Thirty-eight of the 52 patients with hPIDs showed common variable immunodeficiency disorders(CVID), while the remaining 14 had CVID-like conditions(i.e., 11 had isolated IgG subclass deficiencies and 3 had selective IgA deficiencies). The prevalence of most HRCT abnormalities was not significantly different between CVID and CVID-like patients(P > 0.05), except for linear and/or irregular opacities(prevalence of 31.6% in the CVID group and 0 in the CVID-like group; P = 0.0427). Airway wall thickening was the most frequent HRCT abnormality found in both CVID and CVID-like patients(71% of cases in both groups). The presence of tree-in-bud abnormalities was an independent predictor of moderate-to-severe obstructive defects at PFTs(Odds Ratio, OR, of 18.75, P < 0.05), while the presence of linear and/or irregular opacities was an independent predictor of restrictive defects at PFTs(OR = 13.00; P < 0.05).CONCLUSION CVID and CVID-like patients showed similar HRCT findings. Tree-in-bud and linear and/or irregular opacities predicted higher risks of, respectively,obstructive and restrictive defects at PFTs.

Evaluation of myocardial infarction patients after coronary revasculation by dual-phase multi-detector computed tomography:Now and in future

Multidetector-row computed tomography(MDCT) has become one of the major tools in diagnosing and evaluating patients with coronary artery disease in recent years.In selected patients,MDCT has been shown to provide more reliable accuracy in detection of stent patency than invasive coronary angiography.Chiou et al reported a delicate infarcted myocardium at-risk score.According to their results,the MDCT-based myocardium at-risk score had a good correlation with the thallium 201 ST-segment elevation myocardial infarction-based summed difference score(r = 0.841,P < 0.001).They claimed that dual-phase MDCT is useful in detecting different patterns of obstructive lesions and the extent of myocardium at risk.In this commentary,we discuss the current status of the clinical application of MDCT in patients with myocardial infarction in relation to evaluating the myocardial perfusion defect,detecting reversible myocardial ischemia,assessing myocardial viability,estimating target lesion restenosis,and calculating of fractional flow reserve from MDCT.