Differentiating Uterine Sarcoma From Atypical Leiomyoma on Preoperative Magnetic Resonance Imaging Using Logistic Regression Classifier: Added Value of Diffusion-Weighted Imaging-Based Quantitative Parameters.

OBJECTIVE: To evaluate the added value of diffusion-weighted imaging (DWI)-based quantitative parameters to distinguish uterine sarcomas from atypical leiomyomas on preoperative magnetic resonance imaging (MRI). MATERIALS AND METHODS: A total of 138 patients (age, 43.7 ± 10.3 years) with uterine sarcoma (n = 44) and atypical leiomyoma (n = 94) were retrospectively collected from four institutions. The cohort was randomly divided into training (84/138, 60.0%) and validation (54/138, 40.0%) sets. Two independent readers evaluated six qualitative MRI features and two DWI-based quantitative parameters for each index tumor. Multivariable logistic regression was used to identify the relevant qualitative MRI features. Diagnostic classifiers based on qualitative MRI features alone and in combination with DWI-based quantitative parameters were developed using a logistic regression algorithm. The diagnostic performance of the classifiers was evaluated using a cross-table analysis and calculation of the area under the receiver operating characteristic curve (AUC). RESULTS: Mean apparent diffusion coefficient value of uterine sarcoma was lower than that of atypical leiomyoma (mean ± standard deviation, 0.94 ± 0.30 10-3 mm²/s vs. 1.23 ± 0.25 10-3 mm²/s; P < 0.001), and the relative contrast ratio was higher in the uterine sarcoma (8.16 ± 2.94 vs. 4.19 ± 2.66; P < 0.001). Selected qualitative MRI features included ill-defined margin (adjusted odds ratio [aOR], 17.9; 95% confidence interval [CI], 1.41-503, P = 0.040), intratumoral hemorrhage (aOR, 27.3; 95% CI, 3.74-596, P = 0.006), and absence of T2 dark area (aOR, 83.5; 95% CI, 12.4-1916, P < 0.001). The classifier that combined qualitative MRI features and DWI-based quantitative parameters showed significantly better performance than without DWI-based parameters in the validation set (AUC, 0.92 vs. 0.78; P < 0.001). CONCLUSION: The addition of DWI-based quantitative parameters to qualitative MRI features improved the diagnostic performance of the logistic regression classifier in differentiating uterine sarcomas from atypical leiomyomas on preoperative MRI.

Efficiency of Non-Contrast-Enhanced Liver Imaging Sequences Added to Initial Rectal MRI in Rectal Cancer Patients.

PURPOSE: The purpose of this study was to estimate the value of addition of liver imaging to initial rectal magnetic resonance imaging (MRI) for detection of liver metastasis and evaluate imaging predictors of a high risk of liver metastasis on rectal MRI. METHODS: We enrolled 144 patients who from October 2010 to May 2013 underwent rectal MRI with T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) (b values = 50, 500, and 900 s/mm2) of the liver and abdominopelvic computed tomography (APCT) for the initial staging of rectal cancer. Two reviewers scored the possibility of liver metastasis on different sets of liver images (T2WI, DWI, and combined T2WI and DWI) and APCT and reached a conclusion by consensus for different analytic results. Imaging features from rectal MRI were also analyzed. The diagnostic performances of CT and an additional liver scan to detect liver metastasis were compared. Multivariate logistic regression to determine independent predictors of liver metastasis among rectal MRI features and tumor markers was performed. This retrospective study was approved by the Institutional Review Board, and the requirement for informed consent was waived. RESULTS: All sets of liver images were more effective than APCT for detecting liver metastasis, and DWI was the most effective. Perivascular stranding and anal sphincter invasion were statistically significant for liver metastasis (p = 0.0077 and p = 0.0471), while extramural vascular invasion based on MRI (mrEMVI) was marginally significant (p = 0.0534). CONCLUSION: The addition of non-contrast-enhanced liver imaging, particularly DWI, to initial rectal MRI in rectal cancer patients could facilitate detection of liver metastasis without APCT. Perivascular stranding, anal sphincter invasion, and mrEMVI detected on rectal MRI were important imaging predictors of liver metastasis.

Entrapped inferior vena cava between 2 lumbar vertebrae.

Inferior vena cava (IVC) obstruction can have several underlying causes, and its clinical symptoms vary. Although there are several reported cases of traumatic jejunal entrapment between 2 vertebral bodies, there is no report of intervertebral IVC entrapment causing partial IVC obstruction. We present the first case of IVC entrapment between 2 vertebral bodies caused by compression fracture of the lumbar spines combined with an injured anterior longitudinal ligament.

Cavernous mesenteric lymphangiomatosis mimicking metastasis in a patient with rectal cancer: a case report.

Lymphangioma usually occurs in children and usually involves the skin. Mesenteric lymphangioma is extremely rare in adults. Typically, lymphangioma appears on computed tomography (CT) as a lower attenuation of a cystic mass, however, some cases appear to be a solid mass. We describe the CT and 18F-FDG positron emission tomography/CT appearance in a case of jejunal and mesenteric cavernous lymphangiomatosis mimicking metastasis in an adult patient with rectal cancer.

Diffuse hepatic hemangiomatosis without extrahepatic involvement in an adult patient.

We report an extremely rare case of a diffuse hepatic hemangiomatosis without extrahepatic involvement in an adult. The imaging findings of this tumor were similar to those of a hepatic hemangioma and included contrast enhancement with a centripetal filling pattern of the entire hepatic tumor on the delayed phase of a dynamic CT and inhomogeneous diffuse uptake of the entire tumor on blood-pool images obtained five hours later on a 99mTc-labeled red blood cell scan. Despite its rarity, diffuse hepatic hemangiomatosis can be suggested in adult patients with diffusely involved hepatic tumors showing the radiological findings of a hepatic hemangioma.

Myxoid liposarcoma involving the liver, subcutaneous tissue, and epidural space in a polycystic disease patient.

We present a case of a myxoid liposarcoma involving the liver, subcutaneous tissue, and epidural space in a polycystic disease patient with minimally increased F-18 FDG activity and review the image findings of myxoid liposarcoma.

Meteorin regulates angiogenesis at the gliovascular interface.

Brain microvasculature requires a coordinated interaction between endothelial cells and astrocytes at the gliovascular interface. However, the role of the factors involved in that interaction and expressed by these cells is poorly understood. In this study, we demonstrate that Meteorin is highly expressed in astrocytes of the brain and retina during the late embryonic and postnatal stages of mouse development. Most notably, Meteorin is localized to the astrocyte endfeet that surround the blood vessels. To investigate the role of Meteorin in perivascular astrocytes, we depleted endogenous levels of Meteorin in cultured astrocytes using siRNA, and found that Meteorin attenuates angiogenic activity indirectly via astrocyte-derived thrombospondin-1/-2 (TSP-1/-2). Exogenous treatment of astrocytes with Meteorin protein also promotes astrocyte expression and secretion of TSP-1/-2. The conditioned media from the Meteorin-treated astrocytes attenuated angiogenic activity of microvascular endothelial cells. This activity was reversed by inhibiting the binding of TSP-1/-2 to its receptor. Furthermore, we found that TSP-1/-2 was co-localized with Meteorin in the developing brain. Therefore, our data strongly suggests that Meteorin is expressed and secreted by perivascular astrocytes and the secreted protein upregulates TSP-1/-2 to attenuate angiogenesis in the surrounding endothelial cells and to promote vascular maturation.

Comparison of virtual cystoscopy, multiplanar reformation, and source CT images with contrast material-filled bladder for detecting lesions.

OBJECTIVE: The objective of our study was to compare the diagnostic accuracy of virtual cystoscopy, multiplanar reformation, and source CT images for lesion detection in the contrast material-filled bladder. SUBJECTS AND METHODS: Two observers independently evaluated 47 patients (28 men and 19 women; mean age +/- SD, 59 +/- 16 years) with virtual cystoscopy, multiplanar reconstruction, and source CT images acquired with contrast material-filled bladder using an MDCT scanner (detector array, 4 x 1.25 mm; beam pitch, 0.75). Agreement between the two observers was evaluated for the three reconstruction methods using kappa statistics. Using the conventional cystoscopic findings as a reference, we compared the results of the three reconstruction techniques both by bladder site and by patient using the McNemar test. RESULTS: The interobserver agreement for the number of positive sites was excellent for virtual cystoscopy (kappa = 0.816), fair for multiplanar reconstruction (kappa = 0.461), and good for source CT images kappa = 0.676). For both observers, the sensitivity for lesion detection by bladder site was significantly greater with virtual cystoscopy (observer 1, 95%; observer 2, 90%) than with multiplanar reconstruction (78% and 60%) and source CT (68% and 65%) images (p < 0.05), whereas the specificity by bladder site and the sensitivity and specificity by patient did not differ with the three methods (p > 0.05). For determining the presence or absence of lesion at each site, virtual cystoscopy was more accurate than multiplanar reconstruction and source CT images for both observers (p < 0.05). CONCLUSION: Virtual cystoscopy is more accurate than multiplanar reconstruction and source CT images for the detection of lesions in the bladder.

CT and MRI findings of sex cord-stromal tumor of the ovary.

OBJECTIVE: The purpose of this article was to research the clinical and imaging features of sex cord-stromal tumors of the ovary to help in specific diagnosis of ovarian tumors. Sex cord-stromal tumors of the ovary are rare ovarian neoplasms, which arise from stromal cells and primitive sex cords in the ovary. The common types are granulosa cell tumors, fibrothecomas, sclerosing stromal tumors, and Sertoli-Leydig cell tumors. They account for most of the hormonally active ovarian tumors. They have characteristic imaging features in each type of the tumor. CONCLUSION: Clinical and radiologic clues are helpful in differential diagnosis from the more common epithelial tumors; sex cord-stromal tumors primarily are treated surgically and have generally good prognosis.

Bladder cancer: analysis of multi-detector row helical CT enhancement pattern and accuracy in tumor detection and perivesical staging.

PURPOSE: To evaluate the enhancement pattern of bladder cancer and the accuracy of multi-detector row helical computed tomography (CT) in the detection and staging of bladder cancer. MATERIALS AND METHODS: In 20 patients, the attenuation value of bladder cancer was measured on dynamic contrast material-enhanced multiphasic CT images obtained with scanning delays of 40, 60, 80, and 100 seconds. In 67 patients, CT data were obtained with a 60-second scanning delay that covered the bladder (section thickness, 2.5 mm; beam pitch, 1.5) and a 180-second scanning delay that covered the abdomen (section thickness, 5 mm; beam pitch, 1.5). We prospectively evaluated CT images and compared findings at CT with findings at histologic examination. We evaluated cancer detection rate, positive predictive value of cancer detection, and sensitivity and specificity in the diagnosis of perivesical invasion. RESULTS: The attenuation value of bladder cancers was significantly higher on 60- (105 HU +/- 16) and 80-second (97 HU +/- 15) delayed CT images than on the other images (P <.05). The cancer detection rate and positive predictive value for cancer detection were 97% and 95%, respectively, in 67 patients and increased to 100% and 100%, respectively, in 44 patients with a time interval of 7 or more days between transurethral resection of the bladder (TURB) and CT examination. Sensitivity and specificity in the diagnosis of perivesical invasion were 89% and 95%, respectively, in 67 patients and increased to 92% and 98%, respectively, in 44 patients with a time interval of 7 or more days between TURB and CT examination. CONCLUSION: Bladder cancer tends to show peak enhancement with the 60-second scanning delay. Multi-detector row helical CT is useful in the detection and staging of bladder cancer.

Angiomyolipoma with minimal fat: differentiation from renal cell carcinoma at biphasic helical CT.

PURPOSE: To compare various computed tomographic (CT) features of angiomyolipoma (AML) with minimal fat with those of size-matched renal cell carcinoma (RCC). MATERIALS AND METHODS: Eighty-one patients (19 with AML with minimal fat [mean diameter, 2.8 cm; range, 1.5-4.5 cm] and 62 with RCC [mean diameter, 3.1 cm; range, 1.8-4.5 cm]) who had undergone biphasic CT (ie, CT with unenhanced, corticomedullary, and early excretory phase scanning) were evaluated. Two reviewers who were unaware of the diagnosis retrospectively recorded tumor attenuation on unenhanced scans, enhancement characteristics (ie, homogeneity of enhancement, amount of enhancement, enhancement pattern over time), tumor margin, location of tumor center, intratumoral calcification, perinephric changes, and patient age and sex. The predictive value of each CT finding was determined by using multivariate logistic regression analysis. RESULTS: Homogeneous enhancement (observed in 79% of AMLs vs 5% of RCCs; odds ratio, 37) and prolonged enhancement pattern (observed in 58% of AMLs vs 10% of RCCs; odds ratio, 42) were valuable predictors for differentiating AML with minimal fat from RCC at multivariate analysis (P <.05 for both). When both CT findings were used as a criterion for differentiating AML from RCC, positive and negative predictive values were 91% (10 of 11 tumors) and 87% (61 of 70 tumors), respectively. Fifty-three percent of AMLs versus 13% of RCCs showed high tumor attenuation on unenhanced scans (P =.04), whereas RCCs showed greater mean enhancement than AMLs (114 HU +/- 44 [SD] vs 73 HU +/- 30 in corticomedullary phase and 66 HU +/- 24 vs 49 HU +/- 20 in early excretory phase) and a male predominance (male-to-female ratio, 50:12 vs 8:11; P =.001). CONCLUSION: Biphasic helical CT may be useful in differentiating AML with minimal fat from RCC, with homogeneous tumor enhancement and prolonged enhancement pattern being the most valuable CT findings.

Living donor kidneys: usefulness of multi-detector row CT for comprehensive evaluation.

PURPOSE: To evaluate in living renal donors the usefulness of multi-detector row computed tomography (CT) in the assessment of renal vasculature and the upper urinary tract. MATERIALS AND METHODS: Four-channel multi-detector row CT scans were obtained in 77 patients. Vascular phase scans were used for CT angiography; excretory phase scans, for CT urography. At CT angiography, two independent observers evaluated the number of arteries and veins and the presence of early-branching arteries. CT urographic images were evaluated with regard to the opacification of the urinary tract and for abnormalities. Findings of CT angiography and urography were compared with surgical findings. Interobserver agreement between CT angiographic and surgical findings was quantified with weighted kappa statistics. Sensitivity and specificity of CT angiography in identifying supernumerary vessels and early-branching arteries were also evaluated. To evaluate the radiation dose to patients, weighted CT dose index (DI) was assessed for each scan. RESULTS: Agreement between CT angiographic and surgical findings was excellent for the number of renal arteries (kappa = 0.896) and veins (kappa = 0.843). Detection rate of CT angiography was 98% (89 of 91) for arteries and 98% (83 of 85) for veins. The respective sensitivity and specificity of CT angiography were 86% (12 of 14) and 100% (65 of 65) for supernumerary arteries, 100% (11 of 11) and 100% (66 of 66) for early-branching arteries, and 75% (six of eight) and 100% (69 of 69) for supernumerary veins. At CT urography, collecting systems and proximal ureters were well opacified in all patients; two patients had underrotated kidneys without obstruction. The weighted CT DI was 10.19 mGy for unenhanced and excretory phase scans and 12.88 mGy for the vascular phase scan. CONCLUSION: Multi-detector row CT can help assess well the renal vasculature and the urinary tract of living renal donors.