Proposed nomogram predicting neoplastic ampullary obstruction in patients with a suspected ampulla of Vater lesion on CT.

PURPOSE: To stratify and weigh the computed tomography (CT) imaging and clinical features differentiating a neoplastic ampullary obstruction from a non-neoplastic ampullary obstruction and to develop a nomogram for estimating individualized risk of neoplastic potential in patients with a suspected ampulla of Vater (AOV) lesion on CT. METHODS: 135 patients (92 non-neoplastic and 43 neoplastic) with a suspected ampullary obstruction on a CT scan between February 2015 and May 2019 were included after the exclusion criteria were applied. Significant imaging and clinical findings of the neoplastic lesions were assessed using univariate and multivariate logistic regression analyses. Based on the significant variables in the multivariate analysis, a nomogram was developed to predict neoplastic potential in patients suspected of ampullary obstruction. The area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic value in the external validation cohort (36 non-neoplastic and 13 neoplastic). RESULTS: The multivariate analysis revealed that the presence of an AOV mass (odds ratio (OR), 77.21; 95% confidence intervals (CI) 1.51-3950.38), AOV size > 12 mm (OR, 23.93; 95% CI 2.96-193.60), total bilirubin > 1.2 mg/dl (OR, 9.99; 95% CI 1.37-73.06) and age ≤ 63 years (OR, 7.52; 95% CI 1.33-42.48) were independent significant parameters that predicted a neoplastic lesion in the AOV. The AUC for the nomogram was 0.93 on the internal validation and 0.91 (95% CI 0.79-0.97) on the external validation. CONCLUSIONS: A nomogram using imaging and clinical findings was useful to estimate a neoplastic ampullary obstruction in patients with a suspected AOV lesion on CT and suggests a further evaluation.

A radiomics nomogram for predicting transcatheter arterial chemoembolization refractoriness of hepatocellular carcinoma without extrahepatic metastasis or macrovascular invasion.

OBJECTIVE: A radiomics nomogram for pretreatment prediction of TACE refractoriness was developed and validated for hepatocellular carcinoma (HCC) without extrahepatic metastasis or macrovascular invasion. MATERIALS AND METHODS: This study included 80 patients with HCC without extrahepatic metastasis or macrovascular involvement treated with TACE between July 2016 and November 2018. The datasets were divided into a training set (80%) and a test set (20%) for feature selection and tenfold cross-validation. Forty radiomic features were extracted from arterial-phase computed tomography (CT) using the Local Image Features Extraction software. The Lasso regression model was used for radiomics signature selection. The Lasso regression model was used for radiomics signature selection and the selected signatures were validated using the Mann-Whitney U-test. The radiomics nomogram was developed based on a multivariate logistic regression model incorporating the Rad-score, CT imaging factors, and clinical factors, and it was validated. RESULTS: The Rad-score, which consists of the Gray-Level Zone Length Matrix (GLZLM)-Long-Zone Low Gray-Level Emphasis (LZLGE) and GLZLM-Gray-Level Non-Uniformity (GLNU), T-stage, log α-fetoprotein (AFP), and bilobar distribution were significantly associated with TACE refractoriness (p < 0.05). Predictors in the radiomics nomogram were the Rad-score and T-stage (Rad-score + T-stage), Rad-score and bilobar distribution (Rad-score + bilobar distribution), or Rad-score and logAFP (Rad-score + logAFP). The multivariate logistic regression model showed a good predictive performance (Rad-score + T-stage, AUC, 0.95; Rad-score + bilobar distribution, AUC 0.91; and Rad-score + logAFP, AUC, 0.91). CONCLUSION: The radiomics nomogram could be used for the pretreatment prediction of TACE refractoriness.

A differential risk assessment and decision model for Transarterial chemoembolization in hepatocellular carcinoma based on hepatic function.

BACKGROUND: The decision of transarterial chemoembolization (TACE) initiation and/or repetition remains challenging in patients with unresectable hepatocellular carcinoma (HCC). The aim was to develop a prognostic scoring system to guide TACE initiation/repetition. METHODS: A total of 597 consecutive patients who underwent TACE as their initial treatment for unresectable HCC were included. We derived a prediction model using independent risk factors for overall survival (OS), which was externally validated in an independent cohort (n = 739). RESULTS: Independent risk factors of OS included Albumin-bilirubin (ALBI) grade, maximal tumor size, alpha-fetoprotein, and tumor response to initial TACE, which were used to develop a scoring system ("ASAR"). C-index values for OS were 0.733 (95% confidence interval [CI] = 0.570-0.871) in the derivation, 0.700 (95% CI = 0.445-0.905) in the internal validation, and 0.680 (95% CI = 0.652-0.707) in the external validation, respectively. Patients with ASAR< 4 showed significantly longer OS than patients with ASAR≥4 in all three datasets (all P < 0.001). Among Child-Pugh class B patients, a modified model without TACE response, i.e., "ASA(R)", discriminated OS with a c-index of 0.788 (95% CI, 0.703-0.876) in the derivation, and 0.745 (95% CI, 0.646-0.862) in the internal validation, and 0.670 (95% CI, 0.605-0.725) in the external validation, respectively. Child-Pugh B patients with ASA(R) < 4 showed significantly longer OS than patients with ASA(R) ≥ 4 in all three datasets (all P < 0.001). CONCLUSIONS: ASAR provides refined prognostication for repetition of TACE in patients with unresectable HCC. For Child-Pugh class B patients, a modified model with baseline factors might guide TACE initiation.

Diagnostic performance of a minimized protocol of non-contrast MRI for hepatocellular carcinoma surveillance.

PURPOSE: To evaluate the per-patient diagnostic performance of a minimized non-contrast MRI protocol for hepatocellular carcinoma (HCC) surveillance in cirrhotic liver, as well as factors affecting diagnostic sensitivity. METHODS: A total of 226 patients who underwent MRI for HCC surveillance over an 8 year period were included in this retrospective study. Set1 consisted of diffusion-weighted imaging and respiratory-triggered, fast-spin echo T2-weighted imaging with fat suppression. Set2 included T1-weighted in/opposed-phase images added to the images from Set1. Image sets were scored as positive or negative for HCC according to predetermined criteria by two readers independently. The diagnostic performance of the two sets in conjunction with α-fetoprotein (AFP) was assessed and compared using the McNemar test. Logistic regression was used to determine factors that affected sensitivity. RESULTS: The sensitivity, specificity, and accuracy of Set1 of readers 1 and 2 were 84.4%/87.3%, 86.8%/86.8%, and 85.0%/87.2%, respectively; and those for Set2 were 87.3%/89.6%, 81.1%/79.2%, and 85.8/87.2%, respectively. The sensitivities of the sets were not significantly different (p = 0.063). Sensitivities of both sets in conjunction with AFP were higher than those of MRI alone without statistical significance (87.3%/89.6%, p = 0.063/> 0.99; 89.6%/89.6%, p = 0.125/> 0.99). In very early-stage HCC, the sensitivities of Sets1 and 2 were 73.1%/76.9% and 76.9%/82.7%, respectively. Perihepatic ascites and size less than 2 cm were associated with sensitivity (p < 0.05). CONCLUSIONS: A minimized non-contrast MRI protocol consisting of Fat-sat T2WI and DWI is highly sensitive and may be a viable method for HCC surveillance of the cirrhotic liver. The inclusion of T1-weighted in/opposed-phase and AFP may increase this sensitivity.

The Efficacy of Cone-Beam CT-Based Liver Perfusion Mapping to Predict Initial Response of Hepatocellular Carcinoma to Transarterial Chemoembolization.

PURPOSE: To evaluate efficacy of cone-beam CT-based liver perfusion mapping obtained immediately following conventional transarterial chemoembolization of hepatocellular carcinoma (HCC) for assessing tumor vascularity, technical success of chemoembolization, and treatment response. MATERIALS AND METHODS: From July 2015 to June 2016, 35 patients with 57 HCCs who underwent cone-beam CT with post-processing software via conventional transarterial chemoembolization for HCC and follow-up examination were included. Three reviewers evaluated technical success on angiography, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, and cone-beam CT-based liver perfusion mapping after transarterial chemoembolization per tumor and per patient. Parenchymal blood volume (PBV) was measured. Treatment response was determined on follow-up CT, MR imaging, or histopathology according to modified Response Evaluation Criteria In Solid Tumors. Diagnostic performance for detection of a viable tumor was evaluated using multiple logistic regression with C-statistics. RESULTS: Treatment response was 38, 17, 2, and 0 for complete response, partial response, stable disease, and progressive disease per tumor and 18, 15, 2, and 0 per patient. In multiple logistic regression, unenhanced cone-beam CT, contrast-enhanced cone-beam CT, cone-beam CT-based liver perfusion mapping, mean value of PBV, and maximum value of PBV of tumor were significant in response assessment for per tumor and per patient (per tumor, all P < .001; per patient, P = .015, P = .001, P < .001, P = .020, and P = .032). Mean value of PBV of tumor was excellent for evaluating technical success with the highest C-statistic (0.880 and 0.920 for per tumor and per patient), followed by that of visual assessment of cone-beam CT-based liver perfusion mapping (0.864 and 0.908). CONCLUSIONS: Cone-beam CT-based liver perfusion mapping provided reliable images to evaluate technical success after transarterial chemoembolization of HCC by qualitative visual assessment and quantitative perfusion values.

Liver fibrosis staging with a new 2D-shear wave elastography using comb-push technique: Applicability, reproducibility, and diagnostic performance.

OBJECTIVE: To evaluate the applicability, reproducibility, and diagnostic performance of a new 2D-shear wave elastography (SWE) using the comb-push technique (2D CP-SWE) for detection of hepatic fibrosis, using histopathology as the reference standard. MATERIALS AND METHODS: This prospective study was approved by the institutional review board, and informed consent was obtained from all patients. The liver stiffness (LS) measurements were obtained from 140 patients, using the new 2D-SWE, which uses comb-push excitation to produce shear waves and a time-aligned sequential tracking method to detect shear wave signals. The applicability rate of 2D CP-SWE was estimated, and factors associated with its applicability were identified. Intraobserver reproducibility was evaluated in the 105 patients with histopathologic diagnosis, and interobserver reproducibility was assessed in 20 patients. Diagnostic performance of the 2D CP-SWE for hepatic fibrosis was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: The applicability rate of 2D CP-SWE was 90.8% (109 of 120). There was a significant difference in age, presence or absence of ascites, and the distance from the transducer to the Glisson capsule between the patients with applicable LS measurements and patients with unreliable measurement or technical failure. The intraclass correlation of interobserver agreement was 0.87, and the value for the intraobserver agreement was 0.95. The area under the ROC curve of LS values for stage F2 fibrosis or greater, stage F3 or greater, and stage F4 fibrosis was 0.874 (95% confidence interval [CI]: 0.794-0.930), 0.905 (95% CI: 0.832-0.954), and 0.894 (95% CI: 0.819-0.946), respectively. CONCLUSION: 2D CP-SWE can be employed as a reliable method for assessing hepatic fibrosis with a reasonably good diagnostic performance, and its applicability might be influenced by age, ascites, and the distance between the transducer and Glisson capsule.

Combined Undifferentiated and Neuroendocrine Carcinomas of the Gallbladder Appearing as Two Separate Lesions: A Case Report with Radiological-Pathological Correlation.

We report herein a rare case of incidentally detected combined undifferentiated and neuroendocrine carcinomas of the gallbladder. An incidental gallbladder malignancy was revealed on abdominal ultrasound and multi-detector computed tomography in a 54-year-old man. A short distance from the main polypoid hypoechoic mass at the fundus of the gallbladder, focal wall thickening was noted with prominently increased power Doppler flow. Extended cholecystectomy was performed, and histology confirmed the main polypoid mass as undifferentiated carcinoma and the separate nodule as neuroendocrine carcinoma. To our knowledge, this is the first report presenting two separate lesions of combined gallbladder carcinomas by radiological features.

Anticancer effect of arsenic trioxide on cholangiocarcinoma: in vitro experiments and in vivo xenograft mouse model.

The purpose of our study was to investigate anticancer activity of arsenic trioxide (As2O3) on cholangiocarcinoma through in vitro and in vivo experiments using human cholangiocarcinoma cancer cells (CC-t6 cells) and a nude mouse model. The effect of As2O3 on CC-t6 cell survival was determined in vitro using MTT assay. Analysis of cell cycle phase distribution and quantification of apoptosis/necrosis, which were achieved by flow cytometry, were performed in order to understand the mechanism of As2O3. In vivo experiment was performed to assess the effectiveness of local injection of As2O3 on tumor inhibition by comparing the following three groups each consisting of five nude mouse xenograft models: high dose As2O3 (5 mg/kg), low dose As2O3 (1 mg/kg), and saline. In MTT assay, As2O3 inhibited the growth of CC-t6 cells more effectively than cisplatin or adriamycin at concentrations between 1 and 100 µM for most time points between 24 and 72 h (p < 0.05). With increased concentration of As2O3, there was dose-dependent increase in G 0/G 1 phase and dose-dependent decrease in S phase. As2O3-mediated inhibition of cell viability was achieved via induction of apoptosis and necrosis in a dose-dependent manner. Injection of As2O3 into CC-t6-induced tumors in nude mice inhibited the growth of subcutaneous tumor xenografts. As2O3 treatment dose-dependently inhibited the proliferation of CC-t6 cells via G 0/G 1 phase arrest and retarded tumor growth in nude mice, suggesting that As2O3 may be effective in the treatment of cholangiocarcinoma.

Dual-energy CT in the assessment of mediastinal lymph nodes: comparative study of virtual non-contrast and true non-contrast images.

OBJECTIVE: To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes. MATERIALS AND METHODS: A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation ≤ the aorta; 1, > the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed. RESULTS: CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 ± 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (κ value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245). CONCLUSION: VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.

Extrahepatic soft tissue mimicking applicator-tract implantation after percutaneous radiofrequency ablation of hepatic malignancy.

OBJECTIVE: The purpose of our study was to identify extrahepatic soft tissue mimicking applicator-tract implantation after percutaneous radiofrequency ablation of hepatic malignancy on triple-phase dynamic CT. MATERIALS AND METHODS: A database was reviewed for 131 patients who underwent percutaneous radiofrequency ablation for treatment of a hepatic tumor over a 3-year period. Patients who developed extrahepatic soft tissue adjacent to the previous ablation zone mimicking applicator-tract implantation were identified. The clinical features of patients, characteristics of extrahepatic soft tissue on CT, soft-tissue changes on follow-up CT, and histopathologic results were evaluated. RESULTS: Extrahepatic soft tissue developed in five patients (3.8%) at 2-8 months after percutaneous radiofrequency ablation. Extrahepatic soft tissue showed progressive enhancement during the delayed phase of dynamic CT. Four lesions were completely resolved without any treatment. However, one lesion was enlarged and xanthogranulomatous inflammation was diagnosed by percutaneous biopsy. Univariate analysis showed that an index tumor with a subcapsular location and a prior biopsy had high odds ratios. CONCLUSION: The possibility of a benign inflammatory lesion should be considered when extrahepatic soft tissue showing radiologic findings similar to applicator-tract implantation develops after radiofrequency ablation of a hepatic tumor.

Reticular infiltrations alone without mass in the mesentery and omentum identified at contrast-enhanced CT: efficacy of US-guided percutaneous core biopsy.

PURPOSE: To evaluate the diagnostic efficacy of ultrasonographically (US) guided percutaneous core biopsy of reticular infiltrations alone without mass in the mesentery and omentum at contrast material-enhanced abdominal computed tomography (CT). MATERIALS AND METHODS: This study was approved by the institutional review board, and the need for obtaining signed informed consent was waived for this retrospective analysis. From March 2004 to May 2009, 45 patients (mean age, 52.3 years; age range, 21-89 years) with reticular infiltrations alone without mass in the mesentery and omentum at contrast-enhanced abdominal CT underwent US-guided percutaneous core biopsy. Twenty-one men and 24 women were included. The area with the severest infiltrations at CT was targeted during real-time US-guided percutaneous biopsy. Biopsy results were compared with the final results of surgery or follow-up. The diagnostic accuracy of US-guided percutaneous biopsy was then calculated. RESULTS: One patient had an insufficient biopsy specimen. Among the 44 patients with sufficient biopsy specimens, 17 patients had malignancy, 12 had tuberculosis, and 15 had nonspecific inflammation. All 29 patients with malignancy and tuberculosis at biopsy had that confirmed with surgery or follow-up results. Two of 15 patients with nonspecific inflammation at percutaneous biopsy were confirmed as having malignancy at surgery and four as having tuberculosis after improvement with empirical antituberculosis therapy. The diagnostic accuracy of US-guided percutaneous biopsy of reticular infiltrations in the mesentery and omentum was 84%; the sensitivity and specificity was, respectively, 89% and 100% for malignancy, 75% and 100% for tuberculosis, and 90% and 83% for nonspecific inflammation. CONCLUSION: US-guided percutaneous core biopsy is a feasible diagnostic method with high specificity for confirmative diagnosis of reticular infiltrations alone in the mesentery and omentum at contrast-enhanced CT.

Computer-aided evaluation of breast MRI for the residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy.

OBJECTIVE: To evaluate the accuracy of a computer-aided evaluation program (CAE) of breast MRI for the assessment of residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy. MATERIALS AND METHODS: Fifty-seven patients with breast cancers who underwent neoadjuvant chemotherapy before surgery and dynamic contrast enhanced MRI before and after chemotherapy were included as part of this study. For the assessment of residual tumor extent after completion of chemotherapy, the mean tumor diameters measured by radiologists and CAE were compared to those on histopathology using a paired student t-test. Moreover, the agreement between unidimensional (1D) measurement by radiologist and histopathological size or 1D measurement by CAE and histopathological size was assessed using the Bland-Altman method. For chemotherapy monitoring, we evaluated tumor response through the change in the 1D diameter by a radiologist and CAE and three-dimensional (3D) volumetric change by CAE based on Response Evaluation Criteria in Solid Tumors (RECIST). Agreement between the 1D response by the radiologist versus the 1D response by CAE as well as by the 3D response by CAE were evaluated using weighted kappa (k) statistics. RESULTS: For the assessment of residual tumor extent after chemotherapy, the mean tumor diameter measured by radiologists (2.0 ± 1.7 cm) was significantly smaller than the mean histological diameter (2.6 ± 2.3 cm) (p = 0.01), whereas, no significant difference was found between the CAE measurements (mean = 2.2 ± 2.0 cm) and histological diameter (p = 0.19). The mean difference between the 1D measurement by the radiologist and histopathology was 0.6 cm (95% confidence interval: -3.0, 4.3), whereas the difference between CAE and histopathology was 0.4 cm (95% confidence interval: -3.9, 4.7). For the monitoring of response to chemotherapy, the 1D measurement by the radiologist and CAE showed a fair agreement (k = 0.358), while the 1D measurement by the radiologist and 3D measurement by CAE showed poor agreement (k = 0.106). CONCLUSION: CAE for breast MRI is sufficiently accurate for the assessment of residual tumor extent in breast cancer patients receiving neoadjuvant chemotherapy. However, for the assessment of response to chemotherapy, the assessment by the radiologist and CAE showed a fair to poor agreement.

Value of multidetector CT in decision making regarding surgery in patients with small-bowel obstruction due to adhesion.

The aim of this study was to evaluate the value of use of multidetector CT (MDCT) to predict the need for subsequent surgery in patients with small-bowel obstruction (SBO) due to adhesion. During a 3-year period, 128 patients with an SBO due to adhesion were enrolled in this prospective study. Initially, all patients were treated conservatively. Surgery was performed in patients who developed signs of strangulation or did not improve, despite a conservative treatment for at least 5 days. Of the 128 patients, 37 patients eventually underwent surgery. Two radiologists interpreted MDCT findings regarded as predictive indicators for subsequent surgery in consensus. The findings included degree of SBO, presence of transition zone, and an abnormal vascular course. These findings were statistically compared between the group operated on and the group not operated on. A higher degree of SBO, an abnormal vascular course, and the presence of transition zone were more frequently seen in the group of patients operated on (p < 0.001). Sensitivities, specificities, positive and negative predictive values, and risks for the use of MDCT to predict the need for surgery were 100%, 46.1%, 43%, 100%, and 1.9 (1.5 < or = 95% confidence interval (CI) < or = 2.2) for a high-grade obstruction; 100%, 23%, 34.5%, 100%, and 1.3 (1.2 < or = 95% CI < or = 1.5) for the presence of a transition zone; and 70.2%, 90.1%, 74.2%, 88.1%, and 7.1 (3.7 < or = 95% CI < or = 13.7) for the presence of an abnormal course of the mesenteric vessels, respectively. The presence of a high degree of SBO and an abnormal vascular course around transition zone are useful indicators on MDCT to predict the need for surgery in patients with an SBO due to adhesion.

Assessment of musculoskeletal infection in rats to determine usefulness of SPIO-enhanced MRI.

OBJECTIVE: The objective of our study was to evaluate the usefulness of superparamagnetic iron oxide (SPIO)-enhanced MRI in experimental models of infectious disease and to analyze the intracellular uptake of SPIO. MATERIALS AND METHODS: Nine rats with infectious arthritis of the knee or soft-tissue infection were imaged on an MRI unit on days 4-6 after i.v. injection of a bacterial suspension. All animals were imaged on a T2-weighted fast spin-echo sequence before and 24 hours after administration of SPIO. The nine rats were classified into two groups according to the dose of SPIO. We calculated the relative signal-to-noise ratio (SNR) change and compared the relative SNR change with the histologic findings. We analyzed iron-loaded cells and the intracellular uptake of iron particles according to the dose of SPIO. RESULTS: The SNR value decreased in proportion to the increase in the number of iron-laden macrophages or fibroblasts in the wall of the soft-tissue abscess (p < 0.01). The intracellular uptake of iron particles was shown in fibroblasts as well as in macrophages, and their uptake in the fibroblasts was greater than that in the macrophages (p < 0.05). There was no statistically significant difference in the intracellular uptake of iron particles according to the dose of SPIO (p > 0.1). CONCLUSION: SPIO-enhanced MRI can be useful in evaluating infectious disease of the joint or soft tissue and is influenced by the uptake of iron particles in fibroblasts as well as macrophages.

Evaluation of preoperative sonography in acute cholecystitis to predict technical difficulties during laparoscopic cholecystectomy.

PURPOSE: The aim of this study was to evaluate the role of preoperative sonography in predicting technical difficulties during laparoscopic cholecystectomy in patients with acute cholecystitis. METHODS: Sonographic assessment of 14 parameters was performed in 55 patients during a 9-month period: volume of gallbladder (GB), thickness of GB wall, pattern of GB wall thickening, size of largest gallstone, gallstone mobility, adhesion of GB to its bed, fat plane between GB and hepatoduodenal ligament, free fluid in GB fossa, common bile duct (CBD) dilatation, CBD stone(s), color and power Doppler signals in GB wall, and increased color and power Doppler signals in adjacent liver. Each of the 5 operative steps of laparoscopic cholecystectomy was scored as being difficult (1) or not (0). The scores for each step were added to obtain the overall difficulty score (0-5). We evaluated prospectively whether there were significant associations among the preoperative sonographic findings and the overall difficulty score, scores for each of the 5 operative steps, and operation time. RESULTS: The overall difficulty score was significantly associated with a GB volume of 50 cm(3) or more, GB wall thickness of 3 mm or more, and presence of color Doppler signals in the GB wall. Increased GB volume also made dissection of adhesions from the GB and dissection of Calot's triangle more difficult. Extraction of the GB from the abdomen was more difficult with a thickened GB wall or adhesion of the GB to its bed. The presence of a CBD stone, dilatation of the CBD (> or = 8 mm), color Doppler signals in the GB wall, and increased power Doppler signals in the adjacent liver were significantly associated with increased operation time. CONCLUSIONS: Based on our experience, preoperative determination of GB volume, GB wall thickness, and presence of color Doppler signals in the GB wall in patients with acute cholecystitis helps predict technical difficulties during laparoscopic cholecystectomy.

Role of color and power doppler imaging in differentiating between malignant and benign solid breast masses.

PURPOSE: This study analyzed the color and power Doppler signals in solid breast masses and assessed their value in differentiating malignant from benign lesions. METHODS: One hundred twenty-nine biopsy-proven solid breast masses (54 malignant and 75 benign) were evaluated with color and/or power Doppler sonography using a 7-MHz linear-array transducer. We retrospectively analyzed the location, shape, and penetration of the Doppler vascular signals in the breast masses. The location of the vascular signals was categorized as central, peripheral, or both. The shape of the signals was categorized as linear, irregular, branching, or a single dot. A penetrating vessel was defined as a continuous vascular signal extending from outside the lesion to inside it. In 43 cases, power and color Doppler sonograms were compared. RESULTS: Doppler features suggestive of malignant lesions were the presence of both peripheral and central vascularity (odds ratio, 6.0), presence of penetrating vessels (odds ratio, 5.4), and presence of branching vessels (odds ratio, 13.7). Power Doppler sonography was more sensitive than color Doppler sonography in detecting vascular signals in 49% of cases. CONCLUSIONS: Color (power) Doppler imaging is a valuable adjunct to conventional sonography in differentiating between malignant and benign breast lesions.