A deep learning model based on contrast-enhanced computed tomography for differential diagnosis of gallbladder carcinoma

Background:Gallbladder carcinoma(GBC)is highly malignant,and its early diagnosis remains difficult.This study aimed to develop a deep learning model based on contrast-enhanced computed tomography(CT)images to assist radiologists in identifying GBC.Methods:We retrospectively enrolled 278 patients with gallbladder lesions(>10 mm)who underwent contrast-enhanced CT and cholecystectomy and divided them into the training(n=194)and validation(n=84)datasets.The deep learning model was developed based on ResNet50 network.Radiomics and clinical models were built based on support vector machine(SVM)method.We comprehensively compared the performance of deep learning,radiomics,clinical models,and three radiologists.Results:Three radiomics features including LoG_3.0 gray-level size zone matrix zone variance,HHL firstorder kurtosis,and LHL gray-level co-occurrence matrix dependence variance were significantly different between benign gallbladder lesions and GBC,and were selected for developing radiomics model.Multivariate regression analysis revealed that age≥65 years[odds ratios(OR)=4.4,95%confidence interval(CI):2.1-9.1,P<0.001],lesion size(OR=2.6,95%CI:1.6-4.1,P<0.001),and CA-19-9>37 U/mL(OR=4.0,95%CI:1.6-10.0,P=0.003)were significant clinical risk factors of GBC.The deep learning model achieved the area under the receiver operating characteristic curve(AUC)values of 0.864(95%CI:0.814-0.915)and 0.857(95%CI:0.773-0.942)in the training and validation datasets,which were comparable with radiomics,clinical models and three radiologists.The sensitivity of deep learning model was the highest both in the training[90%(95%CI:82%-96%)]and validation[85%(95%CI:68%-95%)]datasets.Conclusions:The deep learning model may be a useful tool for radiologists to distinguish between GBC and benign gallbladder lesions.

Computed tomography imaging and clinical significance of bacterium-positive pulmonary tuberculosis complicated with diabetes

BACKGROUND The increasing prevalence of tuberculosis(TB)and diabetes on a global scale poses a significant health challenge,particularly due to their co-occurrence,which amplifies the severity,recurrence and mortality rates associated with both conditions.This highlights the need for further investigation into their interrelationship.AIM To explore the computed tomography(CT)imaging and clinical significance of bacterium-positive pulmonary TB(PTB)combined with diabetes.METHODS There were 50 patients with bacterium-positive PTB and diabetes,and 50 with only bacterium-positive PTB.The latter were designated as the control group.The CT imaging of the two groups of patients was compared,including lesion range,shape,density and calcification.RESULTS No significant differences were observed in age,gender,smoking and drinking history,high blood pressure,hyperlipidemia and family genetic factors between the groups.However,compared to the patients diagnosed solely with simple bacterium-positive PTB,those with concurrent diabetes showed a wider range of lesions and more complex and diverse morphology on CT images.Among them,intrapulmonary tuberculosis lesions were often accompanied by manifestations of pulmonary infection,such as cavity formation and bronchiectasis.At the same time,diabetes-related signs were often seen on CT images,such as pulmonary infection combined with diabetic pulmonary lesions.Logistic regression analysis identified age and medical history as significant factors influencing the degree of pulmonary infection and CT imaging outcomes in patients with both TB and diabetes.This suggests that older age and specific medical histories may increase the risk or severity of pulmonary damage in these patients.CONCLUSION CT imaging reveals more complex lesions in PTB patients with diabetes,emphasizing the need for careful evaluation and comprehensive analysis to enhance diagnostic accuracy.

Detection of gallbladder stones by dual-energy spectral computed tomography imaging

AIM:To evaluate the detectability of gallbladder stones by dual-energy spectral computed tomography(CT) imaging.METHODS:Totally 217 patients with surgically confirmed gallbladder stones were retrospectively analyzed who underwent single-source dual-energy CT scanning from August 2011 to December 2013. Polychromatic images were acquired. And post-processing software was used to reconstruct monochromatic(40 ke V and 140 ke V) images,and calcium-lipid pair-wise base substance was selected to acquire calcium base images and lipid base images. The above 5 groups of images were evaluated by two radiologists separately with 10-year experience in CT image reading. In the 5 groups of images,the cases in the positive group and negative group were counted and then the detection rate was calculated. The inter-observer agreement on the scoring results was analyzed by Kappa test,and the scoring results were analyzed by Wilcoxon test,with P < 0.05 indicating that the difference was statistically significant. The stone detection results of the 5 groups of images were analyzed by χ2 test.RESULTS:There was good inter-observer agreement(k = 0.772). In 217 patients with gallbladder stones,there was a statistically significant difference in stone visualization between spectral images(40 ke V,140 ke V,calcium base and lipid base images) and polychromatic images(P < 0.05). 40 ke V monochromatic images were better than 140 ke V monochromatic images(4.90 ± 0.35 vs 4.53 ± 1.15,P < 0.05),and calcium base images were superior to lipid base images(4.91 ± 0.43 vs 4.77 ± 0.63,P < 0.05),but there was no statisticallysignificant difference between 40 ke V monochromatic images and calcium base images(4.90 ± 0.35 vs 4.91 ± 0.43,P > 0.05). In 217 gallbladder stone patients,there were 21,3,28,5 and 12 negative stone cases in polychromatic images,40 ke V images,140 ke V images,calcium base images and lipid base images,respectively,and the differences among the five groups were statistically significant(P < 0.05).CONCLUSION:Monochromatic images and base substance images have a good clinical prospect in the iso-density stone detection.

Intraluminal versus infiltrating gallbladder carcinoma:Clinical presentation,ultrasound and computed tomography

AIM： To compare clinical presentation and ultrasound （US） and computed tomography （CT） sensitivity between intraluminal and infiltrating gallbladder carcinoma （GBCA）. METHODS： This retrospective study evaluated 65 cases of GBCA that were categorized morphologically into the intraluminaI-GBCA （n = 37） and infiltrating-GBCA （n = 28） groups. The clinical and laboratory findings, presence of gallstones, gallbladder size, T-staging, nodal status, sensitivity of preoperative US and CT studies, and outcome were compared between the two groups. RESULTS： There were no significant differences between the two groups with respect to female predominance, presence of abdominal pain, serum aminotransferases level, T2-T4 staging, and regional metastatic nodes. Compared with the patients with intraluminaI-GBCA, those with infiltrating-GBCA were significantly older （65.49 ± 1.51 years vs 73.07 ± 1.90 years）, had a higher frequency of jaundice （3/37 patients vs 13/28 patients） and fever （3/37 patients vs 10/28 patients）, higher alkaline phosphatase （119.36 ± 87.80 IU/L vs 220.68 ± 164.84 IU/L） and total bilirubin （1.74 ± 2.87 mg/L vs 3.50 ± 3.51 mg/L） levels, higher frequency of gallstones （12/37 patients vs 22/28 patients）, smaller gallbladder size （length, 7.47± 1.70 cm vs 6.47 ± 1.83 cm; width, 4.21 ± 1.43 cm vs 2.67 ± 0.93 cm）, and greater proportion of patients with 〈 12 mo survival （16/37 patients vs 18/28 patients）. The sensitivity for diagnosing intraluminal- GBCA with and without gallstones was 63.6% and 91.3% by US, and 80% and 100% by CT, respectively. The sensitivity for diagnosing infiltrating-GBCA with and without gallstones was 12.5% and 25% by US, and 71.4% and 75% by c-r, respectively. CONCLUSION： In elderly women exhibiting small gallbladder and gallstones on US, especially those with jaundice, fever, high alkaline phosphatase and bilirubin levels, CT may reveal concurrent infiltrating-GBCA.

Tuberculosis versus non-Hodgkin's lymphomas involving small bowel mesentery:Evaluation with contrast-enhanced computed tomography

AIM: To evaluate the specific computed tomography (CT) imaging criteria for differentiating tuberculosis involving the small bowel mesenteric lymph nodes from lymphomas. METHODS: We retrospectively reviewed the anatomic distribution,CT enhancement patterns of lymphoma in 18 patients with mesenteric tuberculosis and 22 with untreated non-Hodgkin’s lymphomas (NHL) involving small bowel mesentery (SBM). Of the 18 patients with tuberculosis,9 had purely mesenteric tuberculous lymphadenopathy (TL),and 9 had mesenteric TL accompanied with tuberculous mesenteritis (TLM). RESULTS: CT showed that tuberculosis and NHL mainly affected lymph nodes in the body and root of SBM. Homogeneously enhanced lymph nodes in the body and root of SBM were found more often in the NHL (P < 0.05). Homogeneously mixed peripheral enhanced lymph nodes in the body of SBM were found more often in mesenteric TL and TLM (P < 0.05). Peripheral enhanced lymph nodes in the root of SBM were found more often in mesenteric TL and TLM (P < 0.01). "Sandwich sign" in the root of SBM was observed more often in NHL (P < 0.05). CONCLUSION: Anatomic lymph node distribution,sandwich sign and specific enhancement patterns of lymphadenopathy in SBM on CT images can be used in differentiating between tuberculosis and untreated NHL involving SBM.

Primary esophageal tuberculosis mimicking esophageal carcinoma on computed tomography: A case report

BACKGROUND Tuberculosis(TB)has a rare extrapulmonary manifestation known as esophageal tuberculosis,accounting for 0.2%of total TB patients.Esophageal TB typically presents with dysphagia,with retrosternal pain or odynophagia,but generalized symptoms such as low-grade fever,decreased appetite,and weight loss are also observed.Esophageal carcinoma and Crohn’s disease of the esophagus are important differential diagnoses with similar presentation.CASE SUMMARY We present a case of a 25-year-old male,who presented with esophageal TB mimicking an esophageal carcinoma.Lab work-up,Mantoux test,and chest X-ray were normal.Barium-swallow examination showed moderate dilatation of distal esophagus with a nodular and irregular mucosa.Computed tomography showed significant thickening of thoracic and distal esophagus with infiltration into the lesser omentum and large,centrally necrotic lymph nodes on gastro-hepatic ligament suggestive of a possible malignancy.Esophagoscopy was performed and a biopsy of mural thickening was performed and sent for histopathological examination.The histopathology report and TB-polymerase chain reaction confirmed the diagnosis of esophageal TB.The patient was started on antituberculous therapy(ATT),and complete resolution of symptoms and disease was achieved in 6 mo.CONCLUSION Esophageal TB is an extremely rare,yet important differential diagnosis in a patient presenting with dysphagia.Esophageal TB can mimic esophageal carcinoma on computed tomography scan.The patient responded well to a complete course of ATT.

Gallbladder tuberculosis: False-positive PET diagnosis of gallbladder cancer

Gallbladder tuberculosis (GT) is an extremely rare disease, and very few cases have been reported in the literature. The first case of GT was described in 1870 by Gaucher. A correct preoperative diagnosis of GT is unusual, and it is frequently confused with various gallbladder diseases. We present a new case of a patient who underwent surgery with the preoperative diagnosis of gallbladder cancer after a false positive positron emission tomography scan in the diagnostic work-up.

Radiomics model for distinguishing tuberculosis and lung cancer on computed tomography scans

BACKGROUND Pulmonary tuberculosis(TB)and lung cancer(LC)are common diseases with a high incidence and similar symptoms,which may be misdiagnosed by radiologists,thus delaying the best treatment opportunity for patients.AIM To develop and validate radiomics methods for distinguishing pulmonary TB from LC based on computed tomography(CT)images.METHODS We enrolled 478 patients(January 2012 to October 2018),who underwent preoperative CT screening.Radiomics features were extracted and selected from the CT data to establish a logistic regression model.A radiomics nomogram model was constructed,with the receiver operating characteristic,decision and calibration curves plotted to evaluate the discriminative performance.RESULTS Radiomics features extracted from lesions with 4 mm radial dilation distances outside the lesion showed the best discriminative performance.The radiomics nomogram model exhibited good discrimination,with an area under the curve of 0.914(sensitivity=0.890,specificity=0.796)in the training cohort,and 0.900(sensitivity=0.788,specificity=0.907)in the validation cohort.The decision curve analysis revealed that the constructed nomogram had clinical usefulness.CONCLUSION These proposed radiomic methods can be used as a noninvasive tool for differentiation of TB and LC based on preoperative CT data.

Pediatric vs adult pulmonary tuberculosis:A retrospective computed tomography study

AIM: To compare the manifestations of chest tuberculosis(TB) in pediatric and adult patients based on contrast enhanced computed tomography of chest.METHODS: This was a retrospective study consisting of 152 patients of chest TB including 48 children and 104 adults who had undergone contrast enhanced computed tomography of chest prior to treatment. The patterns and severity of parenchymal, mediastinal and pleural manifestations were analyzed and compared among different age groups.RESULTS: Parenchymal changes observed include consolidation, air space nodules, miliary TB, cavitation, bronchiectasis and fibrosis and these were noted in 60% of children, 71% of adolescents and 76.9% of adults. These changes were more common in right upper lobe in all age groups. There was no significant difference in the frequency of these changes(except nodules) in different age groups. Centrilobular nodules were seen less commonly in children less than 10 years(P = 0.028). Pleural effusion was noted in 28(18.42%) patients and pericardial effusion in 8(5.3%) patients. No significant difference in the serosal involvement is seen among children and adults. Mediastinal adenopathy was seen 70% of children, 76.3% adolescents and 76.9% of adults and paratracheal nodes were seen most frequently. Nodes had similar features(except matting) among all age groups. Matting of nodes was seen more commonly in children(P = 0.014). CONCLUSION: Pediatric chest tuberculosis can have severe parenchymal lesions and nodal involvement similar to adults. The destructive lung changes observed in children needs immediate attention in view of the longer life span they have and hence in formulating optimal treatment strategies.

Persistent port-site sinus in a patient after laparoscopic cholecystectomy:watch out for gallbladder tuberculosis

BACKGROUND:The gallbladder is rarely affected by mycobacterium tuberculosis.The diagnosis of gallbladder tuberculosis is often not suspected prior to surgery or biopsy.METHOD:A young female patient underwent laparoscopic cholecystectomy but presented with a persistently discharging sinus from the port site.RESULTS:The gallbladder biopsy revealed granulomas typical of chronic granulomatous tuberculosis.The condition of the patient was improved by antitubercular treatment.CONCLUSIONS:Presentation of gallbladder tuberculosis as a persistent discharging sinus at the port site in a patient who has undergone a laparoscopic cholecystectomy is extremely rare.The diagnosis was reached by histopathology only.The rarity of the presentation prompted us to report the case.

Tuberculosis Detection from Computed Tomography with Convolutional Neural Networks

Convolutional neural network (CNN), a class of deep neural networks (most commonly used in visual image analysis), has become one of the most influential innovations in the field of computer vision. In our research, we built a system which allows the computer to extract the feature and recognize the image of human lungs and to automatically conclude the health level of the lungs based on database. Here, we built a CNN model to train the datasets. After the training, the system could do certain preliminary analysis already. In addition, we used the fixed coordinate to reduce the noise and combined the Canny algorithm and the Mask algorithm to further improve the accuracy of the system. The final accuracy turned out to be 87.0%, which is convincing. Our system can contribute a lot to the efficiency and accuracy of doctors’ analysis of the patients’ health level. In the future, we will do more improvement to reduce noise and increase accuracy.

Isolated gallbladder tuberculosis mimicking acute cholecystitis:A case report

BACKGROUND Isolated tuberculosis of the gallbladder is extremely rare due to its intrinsic resistance to tuberculous infections.There are reports of gallbladder tuberculosis mimicking cholecystitis or malignancy.However,these presentations were chronic.The diagnosis of gallbladder tuberculosis warrants the need for investigation of additional sites of inoculation and contact tracing of all tuberculosis contacts.Gallbladder tuberculosis is a rare entity but should be suspected in patients from endemic regions with risk factors such as underlying immunosuppression or history of tuberculosis.CASE SUMMARY We present a case of gallbladder tuberculosis presenting as acute cholecystitis.A 44-year-old Filipino lady presented with a 11-d history of right hypochondrium and epigastric pain which worsened after meals with no significant past medical history.She underwent laparoscopic cholecystectomy on the presumptive diagnosis of acute cholecystitis and diagnosed as gallbladder tuberculosis after histopathological examination.The patient did not have features of pulmonary or systemic tuberculosis nor was she immunocompromised.She recovered uneventfully.She was subsequently discharged and followed-up at a hospital in her home country due to financial and social reasons.CONCLUSION Clinicians should have a high index of suspicion for patients in endemic regions presenting with cholecystitis.

Tuberculosis conundrum-current and future scenarios:A proposed comprehensive approach combining laboratory,imaging,and computing advances

Tuberculosis(TB)remains a global threat,with the rise of multiple and extensively drug resistant TB posing additional challenges.The International health community has set various 5-yearly targets for TB elimination:mathematical modelling suggests that a 2050 target is feasible with a strategy combining better diagnostics,drugs,and vaccines to detect and treat both latent and active infection.The availability of rapid and highly sensitive diagnostic tools(Gene-Xpert,TB-Quick)will vastly facilitate population-level identification of TB(including rifampicin resistance and through it,multi-drug-resistant TB).Basicresearch advances have illuminated molecular mechanisms in TB,including the protective role of Vitamin D.Also,Mycobacterium tuberculosis impairs the host immune response through epigenetic mechanisms(histone-binding modulation).Imaging will continue to be key,both for initial diagnosis and follow-up.We discuss advances in multiple imaging modalities to evaluate TB tissue changes,such as molecular imaging techniques(including pathogen-specific positron emission tomography imaging agents),non-invasive temporal monitoring,and computing enhancements to improve data acquisition and reduce scan times.Big data analysis and Artificial Intelligence(AI)algorithms,notably in the AI subfield called“Deep Learning”,can potentially increase the speed and accuracy of diagnosis.Additionally,Federated learning makes multi-institutional/multi-city AI-based collaborations possible without sharing identifiable patient data.More powerful hardware designs-e.g.,Edge and Quantum Computing-will facilitate the role of computing applications in TB.However,“Artificial Intelligence needs real Intelligence to guide it!”To have maximal impact,AI must use a holistic approach that incorporates time tested human wisdom gained over decades from the full gamut of TB,i.e.,key imaging and clinical parameters,including prognostic indicators,plus bacterial and epidemiologic data.We propose a similar holistic approach at the level of national/international policy formulation and implementation,to enable effective culmination of TB’s endgame,summarizing it with the acronym“TB-REVISITED”.

Differentiating Crohn's disease from intestinal tuberculosis

Differentiating Crohn's disease(CD) and intestinal tuberculosis(ITB) has remained a dilemma for most of the clinicians in the developing world, which are endemic for ITB, and where the disease burden of inflammatory bowel disease is on the rise. Although, there are certain clinical(diarrhea/hematochezia/perianal disease common in CD; fever/night sweats common in ITB), endoscopic(longitudinal/aphthous ulcers common in CD; transverse ulcers/patulous ileocaecal valve common in ITB), histologic(caseating/confluent/large granuloma common in ITB; microgranuloma common in CD), microbiologic(positive stain/culture for acid fast-bacillus in ITB), radiologic(long segment involvement/comb sign/skip lesions common in CD; necrotic lymph node/contiguous ileocaecal involvement common in ITB), and serologic differences between CD and ITB, the only exclusive features are caseation necrosis on biopsy, positive smear for acid-fast bacillus(AFB) and/or AFB culture, and necrotic lymph node on cross-sectional imaging in ITB. However,these exclusive features are limited by poor sensitivity, and this has led to the development of multiple multi-parametric predictive models. These models are also limited by complex formulae, small sample size and lack of validation across other populations. Several new parameters have come up including the latest Bayesian meta-analysis, enumeration of peripheral blood T-regulatory cells, and updated computed tomography based predictive score. However, therapeutic anti-tubercular therapy(ATT) trial, and subsequent clinical and endoscopic response to ATT is still required in a significant proportion of patients to establish the diagnosis. Therapeutic ATT trial is associated with a delay in the diagnosis of CD, and there is a need for better modalities for improved differentiation and reduction in the need for ATT trial.

Computed tomography findings for predicting severe acute hepatitis with prolonged cholestasis

AIM: To evaluate the significance of computed tomography (CT) findings in relation to liver chemistry and the clinical course of acute hepatitis. METHODS: Four hundred and twelve patients with acute hepatitis who underwent enhanced CT scanning were enrolled retrospectively. Imaging findings were analyzed for the following variables: gallbladder wall thickness (GWT), arterial heterogeneity, periportal tracking, number and maximum size of lymph nodes, presence of ascites, and size of spleen. The serum levels of alanine aminotransferase, alkaline phosphatase, bilirubin, albumin, and prothrombin time were measured on the day of admission and CT scan, and laboratory data were evaluated every 2-4 d for all subjects during hospitalization. RESULTS: The mean age of patients was 34.4 years, and the most common cause of hepatitis was hepatitis A virus (77.4%). The mean GWT was 5.2 mm. The number of patients who had findings of arterial heterogeneity, periportal tracking, lymph node enlargement > 7 mm, and ascites was 294 (80.1%), 348 (84.7%), 346 (84.5%), and 56 (13.6%), respectively. On multivariate logistic regression, male gender [odds ratio (OR) = 2.569, 95%CI: 1.477-4.469, P = 0.001], toxic hepatitis (OR = 3.531, 95%CI: 1.444-8.635, P = 0.006), level of albumin (OR = 2.154, 95%CI: 1.279-3.629, P = 0.004), and GWT (OR = 1.061, 95%CI: 1.015-1.110, P = 0.009) were independent predictive factors for severe hepatitis. The level of bilirubin (OR = 1.628, 95%CI: 1.331-1.991, P < 0.001) and GWT (OR = 1.172, 95%CI: 1.024-1.342,P = 0.021) were independent factors for prolonged cholestasis in multivariate analysis. CONCLUSION: In patients with acute hepatitis, GWT on CT scan was an independent predictor of severe hepatitis and prolonged cholestasis.

Diagnosis and treatment of gallbladder perforation

AIM： To present our clinical experience with gallbladder perforation cases.METHODS： Records of 332 patients who received medical and/or surgical treatment with the diagnosis of acute cholecystitis in our clinic between 1997 and 2006 were reviewed retrospectively. Sixteen （4.8%） of those patients had gallbladder perforation. The parameters including age, gender, time from the onset of symptoms to the time of surgery, diagnostic procedures, surgical treatment, morbidity, and mortality were evaluated.RESULTS： Seven patients had type I gallbladder perforation, 7 type I gallbladder perforation, and 2 type m gallbladder perforation according to Niemeier＇ s classification. The patients underwent surgery after administration of intravenous electrolyte solutions, and were treated with analgesics and antibiotics within the first 36 h （mean 9 h） after admission. Two patients died of sepsis and multiple organ failure in the early postoperative period. Subhepatic abscess, pelvic abscess, pneumonia, pancreatitis, and acute renal failure were found in 6 patients.CONCLUSION： Early diagnosis and emergency surgical treatment of gallbladder perforation are of crucial importance. Upper abdominal computerized tomography for acute cholecystitis patients may contribute to the preoperative diagnosis of gallbladder perforation.

CT patterns of nodal disease in pediatric chest tuberculosis

AIM:To highlight various patterns of nodal involvement and post treatment changes in pediatric chest tuberculosis based on contrast enhanced computed tomography(CECT) scans of chest.METHODS:This was a retrospective study consisting of 91 patients aged less than 17 years,who attended Paediatrics OPD of All India Institute of Medical Sciences with clinically diagnosed tuberculosis or with chest radiographs suggestive of chest tuberculosis.These patients had an initial chest radiograph as well as CECT of the chest and follow up imaging after 6 mo,and in some cases 9 mo,of completion of anti-tubercular treatment(ATT).CECT of these patients was reviewed for the location and extent of nodal involvement along with determination of site,size,enhancement pattern and calcification.RESULTS:Enlargement of mediastinal or hilar lymph nodes was found in 88/91 patients(96.7%),with the most common locations being paratracheal(84.1%),and subcarinal(76.1%).The most common pattern of enhancement was found to be inhomogenous.The nodes were conglomerate in 56.8% and discrete in 43.2%.In addition,perinodal fat was obscured in 84.1% of patients.In the post-treatment scan,there was 87.4% reduction in the size of the nodes.All nodes post-treatment were discrete and homogenous with perinodal fat present.Calcification was found both pre-and post-treatment,but there was an increase in incidence after treatment(41.7%).There was hence a reduction in size,change in enhancement pattern,and appearance of perinodal fat with treatment.CONCLUSION:Tubercular nodes have varied appearance and enhancement pattern.Conglomeration and obscuration of perinodal fat suggest activity.In residual nodes decision to continue ATT requires clinical correlation.

Pre-operative predictive factors for gallbladder cholesterol polyps using conventional diagnostic imaging

AIM： To determine the clinical data that might be useful for differentiating benign from malignant gallbladder （GB） polyps by comparing radiological methods, including abdominal ultrasonography （US） and computed tomography （CT） scanning, with postoperative pathology findings. METHODS： Fifty-nine patients underwent laparoscopic cholecystectomy for a GB polyp of around 10 ram. They were divided into two groups, one with cholesterol polyps and the other with non-cholesterol polyps. Clinical features such as gender, age, symptoms, size and number of polyps, the presence of a GB stone, the radiologically measured maximum diameter of the polyp by US and CT scanning, and the measurements of diameter from postoperative pathology were recorded for comparative analysis. RESULTS： Fifteen of the 41 cases with cholesterol polyps （36.6%） were detected with US but not CT scanning, whereas all 18 non-cholesterol polyps were observed using both methods. In the cholesterol polyp group, the maximum measured diameter of the polyp was smaller by CT scan than by US.Consequently, the discrepancy between those two scanning measurements was greater than for the non- cholesterol polyp group. CONCLUSION： The clinical signs indicative of a cholesterol polyp include： （1） a polyp observed by US but not observable by CT scanning, （2） a smaller diameter on the CT scan compared to US, and （3） a discrepancy in its maximum diameter between US and CT measurements. In addition, US and the CT scan had low accuracy in predicting the polyp diameter compared to that determined by postoperative pathology.

Intraperitoneal tuberculous abscess: computed tomography features

AIM: To evaluate the computed tomography(CT) features of intraperitoneal tuberculous abscess(IPTA). METHODS: Eight patients with IPTA confirmed by pathology were analyzed retrospectively. The clinical symptoms, medical images, and surgical findings were evaluated. Involvement of the intestine, peritoneum, viscera, and lymph nodes was also assessed. RESULTS: All 8 patients had a history of abdominal discomfort for 1 to 6 mo. Physical examination revealed a palpable abdominal mass in 6 patients. Three patients had no evidence of pulmonary tuberculosis(TB). All IPTAs(11 abscesses) were seen as a multiseptated, peripherally enhanced, hypodense mass with enlarged, rim-enhanced lymph nodes. The largest abscess diameter ranged from 4.5 cm to 12.2 cm. CT showed 2 types of IPTA: Lymph node fusion and encapsulation. Of the 8 patients, one had liver tuberculosis and one had splenic and ovarian tuberculosis. Two cases showed involvement of the terminal ileum and ileocecal junction. Ascites were found in 4 cases. Three patients had peritonitis and mesenteritis. Three patients showed involvement of the omentum. Three patients had histological evidence of caseating granuloma, and 5 had histological evidence of acid-fast bacilli. CONCLUSION: CT is crucial in the detection and characterization of IPTA. Certain CT findings are necessary for correct diagnosis.

Left-sided gallbladder:Its clinical significance and imaging presentations

AIM: To assess the importance of preoperative diagnosis and presentation of left-sided gallbladder using ultrasound (US),CT and angiography. METHODS: Retrospective review of 1482 patients who underwent enhanced CT scanning was performed. Left-sided gallbladder was diagnosed if a right-sided ligamentum teres was present. The image presentations on US,CT and angiography were also reviewed. RESULTS: Left-sided gallbladder was diagnosed in nine patients. The associated abnormalities on CT imaging included portal vein anomalies,absence of umbilical portion of the portal vein in the left lobe of the liver,club-shaped portal vein in the right lobe of the liver,and difficulty in identifying segment Ⅳ. Angiography in six of nine patients demonstrated abnormal portal venous system (trifurcation type in four of six patients). The main hepatic arteries followed the portal veins in all six patients. The segment Ⅳ artery was identified in four of six patients using angiography,although segment Ⅳ was difficult to define on CT imaging. Hepatectomy was performed in three patients with concomitant liver tumor and the diagnosis of left-sided gallbladder was confirmed intraoperatively. CONCLUSION: Left-sided gallbladder is an important clinical entity in hepatectomy due to its associated portal venous and biliary anomalies. It should be considered in US,CT and angiography images that demonstrate no definite segment Ⅳ,absence of umbilical portion of the portal vein in the left lobe,and club-shaped right anterior portal vein.