Computed Tomographic Features of Primary Small Cell Neuroendocrine Tumors of the Gallbladder.

PURPOSE: This study aimed to report the computed tomography (CT) imaging features of primary small cell neuroendocrine tumors of the gallbladder (PSCNETGs). MATERIALS AND METHODS: The CT examinations of 9 patients (5 women, 4 men; median age, 57 years) with histopathologically proven PSCNETG were reviewed. Computed tomographic images were analyzed with respect to morphologic features of primary tumors and accompanying lymph nodes. RESULTS: All PSCNETGs were visible on CT, with a median largest axial diameter of 60 mm (Q1, 30 mm; Q3 mm, 82; range, 25-86 mm). These tumors presented with extraluminal growth (8/9; 89%), heterogeneous enhancement (8/9; 89%), gallbladder replacement greater than 50% (5/9; 56%), hepatic metastases (5/9; 56%), and direct liver involvement by tumor (4/9; 44%). Enlarged lymph nodes were present in all patients (9/9; 100%) with a median largest axial diameter of 39 mm (Q1, 23 mm; Q3, 48 mm; range, 12-62 mm). Vessel encasement by lymph nodes was present in 6 (67%) of 9 patients. CONCLUSION: Primary small cell neuroendocrine tumors of the gallbladder predominantly presents as a large, heterogeneous gallbladder mass with extraluminal growth in association with large metastatic lymph nodes and intrahepatic metastases.

Diffusion-weighted MR imaging of uterine leiomyomas following uterine artery embolization.

PURPOSE: To test whether variations in apparent diffusion coefficient (ADC) values of uterine leiomyomas after uterine artery embolization (UAE) may correlate with outcome and assess the effects of UAE on leiomyomas and normal myometrium with magnetic resonance imaging (MRI). METHODS: Data of 49 women who underwent pelvic MRI before and after UAE were retrospectively reviewed. Uterine and leiomyoma volumes, ADC values of leiomyomas, and normal myometrium were calculated before and after UAE. RESULTS: By comparison with baseline ADC values, a significant drop in leiomyoma ADC was found at 6-month post-UAE (1.096 × 10(-3) mm(2)/s vs. 0.712 × 10(-3) mm(2)/s, respectively; p < 0.0001), but not at 48-h post-UAE. Leiomyoma devascularization was complete in 40/49 women (82 %) at 48 h and in 37/49 women (76 %) at 6 months. Volume reduction and leiomyoma ADC values at 6 months correlated with the degree of devascularization. There was a significant drop in myometrium ADC after UAE. Perfusion defect of the myometrium was observed at 48 h in 14/49 women (28.5 %) in association with higher degrees of leiomyoma devascularization. CONCLUSION: Six months after UAE, drop in leiomyoma ADC values and volume reduction correlate with the degree of leiomyoma devascularization. UAE affects the myometrium as evidenced by a drop in ADC values and initial myometrial perfusion defect. KEY POINTS: • A drop in leiomyoma ADC values is observed 6 months after UAE. • Drop in leiomyoma ADC value is associated with leiomyoma devascularizarion after UAE. • MR 48 h post-UAE allows assessing leiomyoma devascularization. • Myometrium perfusion defect occurs more often in women with a smaller uterus.

MR imaging features of liver involvement by Wilson disease in adult patients.

OBJECTIVE: To describe the magnetic resonance imaging (MRI) presentation of liver involvement in adult patients with Wilson disease (WD) and determine the most indicative appearance of this condition on MRI using a retrospective case-control study. MATERIALS AND METHODS: MRI examinations of 23 adult patients with WD (14 men, 9 women; mean age = 40.4 years) were analyzed by two blinded observers and compared to those obtained in 23 patients with chronic viral hepatitis (14 men, 9 women, mean age = 40.4 years) who were matched for age, gender and severity of chronic liver disease. Images were qualitatively and quantitatively analyzed with respect to imaging presentation. Comparisons were performed using univariate analysis. RESULTS: Honeycomb pattern of hepatic parenchyma was the most discriminating independent variable for the diagnosis of WD (odds ratio, 17.082; 95 % CI 2.092-139.497) (P = 0.0081) but had a sensitivity of 43 % (10/23; 95 % CI 23-66 %). Regular liver contours was the other variable that strongly correlated with the presence of liver involvement by WD (odds ratio, 11.939; 95 % CI 1.503-94.836) (P = 0.0190). CONCLUSION: The honeycomb pattern is the most discriminating independent variable for the diagnosis of liver involvement by WD but has limited sensitivity. Familiarity with this finding may clarify the cause of diffuse hepatic parenchymal abnormalities in patients with unknown WD.

Hepatic involvement in HELLP syndrome: an update with emphasis on imaging features.

HELLP syndrome, which consists of hemolysis, elevated liver enzymes, and low platelet count is an unusual complication of pregnancy that is observed in only 10% to 15% of women with preeclampsia. Hepatic involvement in HELLP syndrome may present with various imaging features depending on the specific condition that includes nonspecific abnormalities such as perihepatic free fluid, hepatic steatosis, liver enlargement, and periportal halo that may precede more severe conditions such as hepatic hematoma and hepatic rupture with hemoperitoneum. Maternal clinical symptoms may be nonspecific and easily mistaken for a variety of other conditions that should be recognized. Because hepatic hematoma occurring in association with preeclampsia and HELLP syndrome is a potentially life-threatening complication, prompt depiction is critical and may help reduce morbidity and mortality. This review provides an update on demographics, risk factors, pathophysiology, and clinical features of hepatic complications due to HELLP syndrome along with a special emphasis on the imaging features of these uncommon conditions.

Budd-Chiari syndrome: a prospective analysis of hepatic vein obstruction on ultrasonography, multidetector-row computed tomography and MR imaging.

PURPOSE: The goal of this study was to prospectively describe the imaging presentation of hepatic vein (HV) obstruction in patients with Budd-Chiari syndrome (BCS) on duplex and color Doppler ultrasonography (DCD-US), multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS: A total of 176 patients with primary BCS (mean age, 33 years; 101 women) were prospectively included. BCS diagnosis was made by direct visualization of HV and/or upper portion of the inferior vena cava (IVC) obstruction on DCD-US and/or MDCT and/or MRI. Location (right, middle, and left HV), type (thrombus, stenosis, or both), and age (recent vs. long-standing) of HV obstruction were described on each imaging examination. RESULTS: HV obstruction was a constant (100%) finding and associated with IVC abnormalities in 51/176 (28.98%) patients. Obstruction of the three HVs was present in 158/176 (89.77%) patients. The prevalences of right, middle, and left HV thrombus were 151/169 (89.35%), 146/169 (86.39%), and 111/169 (65.68%), respectively. Long-standing HV thrombus was observed in more than 92% of patients on the three imaging methods. Agreement between DCD-US, MDCT, and MRI was perfect in the identification of long-standing HV thrombus (κ = 0.9); this agreement was slight to moderate in revealing the type of HV abnormality (i.e., fibrotic cord and non-visible HV). CONCLUSION: Our results indicate that BCS is a chronic and insidious disease, more often discovered at an advanced stage. These results should warrant further evaluation of screening strategies in patients with risk factors for BCS to identify the disease at an early stage.

Focal nodular hyperplasia of the liver: diffusion-weighted magnetic resonance imaging characteristics using high b values.

OBJECTIVE: To qualitatively and quantitatively assess the presentation of hepatic focal nodular hyperplasia (FNH) at diffusion-weighted magnetic resonance imaging (DWMRI) using multiple high b values. MATERIALS AND METHODS: Twenty-five patients with 27 FNHs had liver DWMRI at 1.5 T using free-breathing acquisition and 3 b values (0, 600, 1000 s/mm). Focal nodular hyperplasias were evaluated qualitatively using visual analysis of diffusion-weighted magnetic resonance (DWMR) images and quantitatively using conventional apparent diffusion coefficient (ADC) and normalized ADC measurements. RESULTS: All FNHs (100%) were visible on b0 DWMR images; 26 of the 27 FNHs (96%), on b600 DWMR images; and 21 of the 27 FNHs (78%), on b1000 DWMR images. A total of 18 of the 27 FNHs (67%) exhibited a hyperintense central scar on the b0 DWMR images that remained visible on the b600 and b1000 DWMR images in 6 of the 27 FNHs (22%). Conventional ADC value of FNHs (1.318 × 10 mm/±0.208) was significantly lower than that of adjacent hepatic parenchyma (1.414 × 10 mm/s ± 1.95) (P = 0.0003), although a substantial overlap was found. The use of normalized ADC using the liver as reference organ resulted in a more restricted distribution of ADC values (variation coefficient, 5.3%). CONCLUSIONS: Focal nodular hyperplasias show a wide range of morphological features at DWMRI using high b values. Further studies are needed to fully investigate as to what extent normalized ADC may result in better lesion characterization.

Differentiation between true focal liver lesions and pseudolesions in patients with fatty liver: evaluation of helical CT criteria.

OBJECTIVE: To determine the potential of helical CT for differentiating true lesions from pseudolesions in patients with fatty liver. METHODS: Helical CT of 44 patients with diffuse fatty liver (22 with true lesions; 22 with pseudolesions) were reviewed by two observers with regard to morphological features of visible lesions. Univariate analysis was used to detect discriminating criteria for the diagnosis of true lesions. RESULTS: Interobserver agreement was excellent for 9/10 morphological criteria (kappa = 0.831-1). True lesions were more frequently distant from the liver capsule (50.00% vs. 4.55%), located in the right lobe (72.73% vs. 31.82%), round (86.36% vs. 54.55%), heterogeneous (27.27% vs. 0.00%) and had ill-defined margins (40.91% vs. 13.64%) compared with pseudolesions (P < 0.05). Using univariate analysis, a location distant from the liver capsule was the most discriminating variable to differentiate between true and pseudolesions (P = 0.0060). Hyperattenuating content and round shape were the most sensitive criteria (sensitivity = 90.91% and 86.36%, respectively) for the diagnosis of true lesions, and heterogeneity, vascular displacement and encapsulation were the three most specific ones (specificity = 100.00%). Best accuracy was obtained with an association of the three variables (accuracy = 86.36%). CONCLUSION: Helical CT provides objective and discriminating morphological criteria to differentiate between true lesions and pseudolesions in patients with fatty liver.

Magnetic resonance imaging features of uterine sarcoma and mimickers.

Uterine myometrial tumors are predominantly benign conditions that affect one-third of women and represent the main indication for hysterectomy. Preoperative imaging is of utmost importance for characterization and for precise mapping of myometrial tumors to best guide therapeutic strategy. New minimally invasive therapeutic strategies including morcellation, myolysis, uterine artery embolization and image-guided radiofrequency or focused ultrasound ablation have been developed for the treatment of uterine leiomyoma. However, preoperative differentiation between atypical leiomyomas and leiomyosarcomas is critical on imaging as uterine sarcoma requires a specific surgical technique to prevent dissemination. A single, rapidly growing uterine tumor, associated with endometrial thickening and ascites, in post-menopausal women is suspicious of uterine endometrial stromal sarcoma and carcinosarcoma. Suggestive magnetic resonance imaging features have been described, but overlap in imaging appearance between uterine leiomyosarcomas and cellular leiomyomas makes it challenging to ascertain the diagnosis. This review aims to illustrate the imaging features of uterine sarcomas and potential mimickers to make the reader more familiar with this serious condition which needs special consideration.

Small bowel volvulus due to torsion of pedunculated uterine leiomyoma: CT findings.

Torsion of a uterine leiomyoma is a rare complication that can be life threatening because of ischemia or necrosis. This condition may also lead to gastrointestinal complications such as obstruction or, more rarely, small bowel volvulus. Its diagnosis is difficult and can be facilitated with the use of computed tomography or magnetic resonance imaging. Treatment is based on emergency surgical resection of the twisted uterine leiomyoma and detorsion of the small bowel volvulus.

Neuroendocrine tumors of the small bowel: evaluation with MR-enterography.

PURPOSE: To determine the sensitivity of magnetic resonance (MR)-enterography for the detection of neuroendocrine tumors of the small-bowel (NETSB) and analyze the imaging presentation of NETSB on MR-enterography. PATIENTS & METHODS: The MR-enterography studies (including HASTE, TruFISP, and 3D VIBE MR sequences before and after intravenous administration of a gadolinium-chelate) of 19 patients with pathologically confirmed NETSB were blindly reviewed. Images were analyzed with respect to imaging presentation. Sensitivity of MR-enterography as well as that of each individual MR-enterography sequence for the diagnosis of NETSB was estimated with 95% confidence intervals (CIs). Comparisons between individual MR-enterography sequences were performed using the McNemar test. RESULTS: Twenty-seven NETSBs were confirmed in 19 patients. Overall sensitivity of MR-enterography for NETSB detection was 74% (20/27; 95% CI: 54-89%) on a per-lesion basis. On a per-patient basis, MR-enterography had a sensitivity of 95% (18/19; 95% CI: 74-100%) for the detection of NETSB. Best degrees of sensitivity were achieved with 3D VIBE MR-enterography sequences after intravenous administration of a gadolinium-chelate (Se=95%; 18/19) by comparison with HASTE (Se=26%; 5/19) and TruFISP (Se=26%; 5/19) sequences (P=.00022). Visible focal small-bowel mass, mesenteric stranding, and mesenteric mass were found in 16/19 (84%), 17/19 (89%), and 15/19 (79%) patients, respectively. CONCLUSION: MR-enterography shows highly suggestive features for the diagnosis of NETSB and has high degrees of sensitivity for the diagnosis of NETSB on a per-patient basis.

Acute colonic diverticulitis: an update on clinical classification and management with MDCT correlation.

Currently, the most commonly used classification of acute colonic diverticulitis (ACD) is the modified Hinchey classification, which corresponds to a slightly more complex classification by comparison with the original description. This modified classification allows to categorize patients with ACD into four major categories (I, II, III, IV) and two additional subcategories (Ia and Ib), depending on the severity of the disease. Several studies have clearly demonstrated the impact of this classification for determining the best therapeutic approach and predicting perioperative complications for patients who need surgery. This review provides an update on the classification of ACD along with a special emphasis on the corresponding MDCT features of the different categories and subcategories. This modified Hinchey classification should be known by emergency physicians, radiologists, and surgeons in order to improve patient care and management because each category has a specific therapeutic approach.

Budd-Chiari syndrome: an update on imaging features.

Budd-Chiari syndrome (BCS) is a rare cause of portal hypertension and liver failure. This condition is characterized by an impaired hepatic venous drainage. The diagnosis of BCS is based on imaging, which helps initiate treatment. Imaging findings can be categorized into direct and indirect signs. Direct signs are the hallmarks of BCS and consist of visualization of obstructive lesions of the hepatic veins or the upper portion of the inferior vena cava. Indirect signs, which are secondary to venous obstruction, correspond to intra- and extrahepatic collateral circulation, perfusion abnormalities, dysmorphy and signs of portal hypertension.

MR imaging features of focal liver lesions in Wilson disease.

Hepatic involvement in Wilson disease (WD) manifests as a diffuse chronic disease in the majority of patients. However, in a subset of patients focal liver lesions may develop, presenting with a wide range of imaging features. The majority of focal liver lesions in patients with WD are benign nodules, but there are reports that have described malignant liver tumors or dysplastic nodules in these patients. Because of the possibility of malignant transformation of liver nodules, major concerns have been raised with respect to the management and follow-up of patients with WD in whom focal liver lesions have been identified. The assessment of liver involvement in patients with WD is generally performed with ultrasonography. However, ultrasonography conveys limited specificity so that magnetic resonance (MR) imaging is often performed to improve lesion characterization. This review was performed to illustrate the spectrum of MR imaging features of focal liver lesions that develop in patients with WD. It is assumed that familiarity with the MR imaging presentation of focal liver lesions in WD may help clarify the actual nature of hepatic nodules in patients with this condition.

Intrahepatic and hilar mass-forming cholangiocarcinoma: Qualitative and quantitative evaluation with diffusion-weighted MR imaging.

OBJECTIVE: To qualitatively and quantitatively analyze the presentation of intrahepatic and hilar mass-forming cholangiocarcinoma with diffusion-weighted magnetic resonance imaging (DW-MRI). MATERIALS AND METHODS: Twenty-eight patients with histopathologically proven mass-forming cholangiocarcinoma (hilar, n=17; intrahepatic, n=11) underwent hepatic DW-MRI at 1.5-T using free-breathing acquisition and three b-values (0,400,800s/mm(2)). Cholangiocarcinomas were evaluated qualitatively using visual analysis of DW-MR images and quantitatively with conventional ADC and normalized ADC measurements using liver and spleen as reference organs. RESULTS: All cholangiocarcinomas (28/28; 100%) were visible on DW-MR images. DW-MRI yielded best conspicuity of cholangiocarcinomas than the other MRI sequences (P<0.001). Seven cholangiocarcinomas (7/11; 64%) showed hypointense central area on DW-MR images. Conventional ADC value of cholangiocarcinomas (1.042×10(-3)mm(2)/s±0.221×10(-3)mm(2)/s; range: 0.616×10(-3)mm(2)/s to 2.050×10(-3)mm(2)/s) was significantly lower than that of apparently normal hepatic parenchyma (1.362×10(-3)mm(2)/s±0.187×10(-3)mm(2)/s) (P<0.0001), although substantial overlap was found. No significant differences in ADC and normalized ADC values were found between intrahepatic and hilar cholangiocarcinomas. The use of normalized ADC using the liver as reference organ resulted in the most restricted distribution of ADC values of cholangiocarcinomas (variation coefficient=16.6%). CONCLUSION: There is a trend towards a common appearance of intrahepatic and hilar mass-forming cholangiocarcinomas on DW-MRI but variations may be observed. Familiarity with these variations may improve the diagnosis of mass-forming cholangiocarcinoma.

Transcatheter Arterial Embolization for Postpartum Hemorrhage: Indications, Technique, Results, and Complications.

Postpartum hemorrhage (PPH) is a potentially life-threatening condition, which needs multidisciplinary management. Uterine atony represents up to 80 % of all causes of PPH. Transcatheter arterial embolization (TAE) has now a well-established role in the management of severe PPH. TAE allows stopping the bleeding in 90 % of women with severe PHH, obviating surgery. Pledgets of gelatin sponge as torpedoes are commonly used for safe TAE, and coils, glue, and microspheres have been primarily used in specific situations such as arterial rupture, pseudoaneurysm, and arteriovenous fistula. TAE is a minimally invasive procedure with a low rate of complications, which preserves future fertility. Knowledge of causes of PPH, potential risks, and limitations of TAE is essential for a timely decision, optimizing TAE, preventing irreversible complications, avoiding hysterectomy, and ultimately preserving fertility.

Role and Effectiveness of Percutaneous Arterial Embolization in Hemodynamically Unstable Patients with Ruptured Splanchnic Artery Pseudoaneurysms.

PURPOSE: To assess the role and effectiveness of percutaneous arterial embolization (TAE) in patients with hemodynamic instability due to hypovolemic shock secondary to ruptured splanchnic artery pseudoaneurysms (SAPA). MATERIALS AND METHODS: Seventeen patients (11 men, 6 women; mean age, 53 years) with hemodynamic instability (systolic blood pressure <90 mmHg) due to hypovolemic shock secondary to ruptured SAPA were treated by TAE. Clinical files, multidetector row computed tomography angiography, and angiographic examinations along with procedure details were reviewed. RESULTS: Seventeen SAPAs were present, predominantly located on gastroduodenal or pancreatic arteries (9/17; 53%). Angiography showed extravasation of contrast medium from SAPA in 15/17 patients (88%). Technical success rate of TAE was 100%. TAE was performed using metallic coils in all patients (100%), in association with gelatin sponge in 5/17 patients (29%). TAE allowed controlling the bleeding and returning to normal hemodynamic status in 16/17 patients (94%). In 1/17 patient (6%), surgery was needed to definitively control the bleeding. The mortality and morbidity rate of TAE at 30 days were 0 and 12%, respectively. Morbidity consisted in coil migration in 1/17 patient (6%) and transient serum liver enzyme elevation in 1/17 patient (6%). CONCLUSION: TAE is an effective and safe treatment option for ruptured SAPA in hemodynamically unstable patients, with a success rate of 94%. Our results suggest that TAE should be the favored option in patients with hemodynamic instability due to ruptured SAPA.

Solid-pseudopapillary tumor of the pancreas: MR imaging findings in 21 patients.

PURPOSE: Solid-pseudopapillary tumor (SPT) of the pancreas is a rare, low-grade malignancy, which mostly occurs in adolescent and young adult females. The goal of this study was to retrospectively analyze the magnetic resonance (MR) imaging presentation of SPT of the pancreas. METHODS: We retrospectively reviewed the preoperative MR imaging examinations and the medical, surgical and histopathological records of 21 patients who underwent surgery for SPT of the pancreas. MR imaging included T1-weighted, T2-weighted, and gadolinium chelate-enhanced MR imaging. In addition, 10 patients had diffusion-weighted (DW) MR imaging. MR examinations were retrospectively reviewed for location, size, morphological features and signal intensity of the tumors. RESULTS: Nineteen women and 2 men (median age, 23 years; range, 14-59) were included. Seven patients (7/21; 33%) presented with abdominal symptoms. The median largest tumor diameter was 53mm (range, 32-141 mm). SPTs were located in the pancreatic head, body, and tail in 9 (9/21; 43%), 5 (5/21; 24%) and 7 (7/21, 33%) patients, respectively. All patients (21/21; 100%) had a single SPT. SPTs were more frequently oval (12/21; 57%), predominantly solid (12/21; 57%), fully encapsulated (16/21; 76%), larger than 30 mm (21/21; 100%), hypointense on T1-weighted MR images (21/21, 100%), hyperintense on T2-weighted MR images (21/21; 100%) and with an enhancing capsule after gadolinium-chelate administration (21/21; 100%). CONCLUSIONS: There is trend of appearance for SPT of the pancreas on MR imaging but that variations may be observed in a number of cases. SPT uniformly presents as a single, well-demarcated and encapsulated pancreatic mass.

Angiolipoma of the labia majora: MR imaging findings with histopathological correlation.

Benign soft tissue tumors of the vulva are relatively rare in adult patients. We present the magnetic resonance (MR) imaging features of an angiolipoma of the labia majora that developed in a 58-year-old woman. MR imaging showed a well-circumscribed lesion that was hyperintense on T1-weighted and T2-weighted MR images, and hypointense on fat-suppressed MR images, consistent with fat content. High apparent diffusion coefficient was noticed on diffusion-weighted MR images. Dynamic gadolinium-chelate enhanced MR imaging showed progressive enhancement. Histopathologically, the lesion was predominantly made of mature adipose tissue and contained thin walled vascular channels consistent with angiolipoma.

Multiple intra-abdominal venous thrombosis in ulcerative colitis: role of MDCT for detection.

Patients with ulcerative colitis are at increased risk for venous thrombosis. We report herein the case of a 28-year-old woman who developed multiple intraabdominal venous thrombosis, including partial Budd-Chiari syndrome in association with intracranial venous thrombosis and pulmonary embolism during the relapse of a known ulcerative colitis. Multidetector-row computed tomography (MDCT) allowed depiction of multiple intraabdominal sites of thrombosis including right and medial hepatic veins, left portal vein, splenic vein and left ovarian vein and demonstrated complete resolution of the multiple thrombi after anticoagulant therapy. The association of partial Budd-Chiari syndrome with other thrombi involving portal, splenic and ovarian veins in association with ulcerative colitis, has, to our knowledge never been reported yet. In addition, the potential role of MDCT in the detection of possible multiple thrombosis in patients with ulcerative colitis has never been emphasized.