Yoshihisa Kurosaki

Uterus didelphys associated with obstructed hemivagina and ipsilateral renal agenesis: MR findings in seven cases.

AbstractBackground: Although a specific syndrome of the uterus didelphys, obstructive hemivagina, and ipsilateral renal agenesis had been reported in gynecologic literatures, it is not familiar to radiologists. We introduce this syndrome with radiological, especially MR findings. Methods: Imaging findings and medical records of seven patients with this syndrome were retrospectively reviewed. Results: MR clearly demonstrated uterus didelphys with obstructed hemivagina in six of the seven patients. A remaining one showed uterus didelphys with left-sided hematometra and hematosalpinx who had undergone vaginal septum incision prior to the MR. We could also recognize ipsilateral renal agenesis in all five patients, in whom renal areas were examined on MR. After vaginal septum resection, symptoms disappeared in six patients. We could observe the disappearance of the obstructive complications with MR in three patients. Conclusions: MR can do much for the early diagnosis and the prevention against further complications of this condition because it can demonstrate the müllerian duct anomaly complicated with obstructed hemivagina in detail and even ipsilateral renal agenesis.

Ovarian dysgerminoma. MR and CT appearance

Objective We determined the MR and CT appearance of ovarian dysgerminoma and correlated our findings with the pathologic features. Materials and Methods CT and MR findings of three patients with ovarian dysgerminoma were retrospectively reviewed and compared with the pathologic findings. Results The tumors were divided into lobules by septa that were hypointense or isointense on T2-weighted imaging and showed marked enhancement on Gd-diethylene triamine pentaacetic acid enhanced T1 -weighted imaging and contrast-enhanced CT. These septa corresponded to fibrovascular bundles at histologic examination. Conclusion CT and MR findings characteristic of fibrovascular septa within solid ovarian masses should raise the possibility of dysgerminomas.

Improved CT fat detection in small kidney angiomyolipomas using thin sections and single voxel measurements.

Objective and Methods Seven echogenic renal masses < 1.0 cm in size were studied by CT to make the diagnosis of angiomyolipoma by identifying the presence of fat. Results In four of six lesions, initial 5 mm section CT failed to detect fat, although repeat 3 and/or 1.5 mm section CT was successful in demonstrating fat. In one patient who underwent 3 and 1.5 mm section CT, attenuation values of four voxels were low enough to indicate the presence of fat only on the 1.5 mm sections. Conclusion Measuring single voxel values in the hypoattenuating areas on nonenhanced thin (3 or 1.5 mm) sections is essential for CT diagnosis of small (< 1.0 cm) renal angiomyolipomas.

Systemic arterial supply to normal basal segments of left lower lobe: CT findings.

Objective The purpose of this study was to evaluate the usefulness of CT in making a diagnosis of systemic arterial supply to normal basal segments of the left lower lobe. Materials and Methods We retrospectively reviewed chest radiography (three cases), CT (three cases), and angiography (two cases). Results An anomalous systemic artery arising from the descending aorta was shown as a retrocardiac density on posteroanterior radiography and as a nodular density behind the heart on lateral radiography. Contrast enhanced CT revealed the vascular nature of the density adjacent to the descending aorta. Dynamic CT in one patient demonstrated that the nodular density was composed of an anomalous systemic artery and a prominent inferior pulmonary vein. High-resolution CT showed the interlobar artery distal to the origin of the superior segmental artery to be absent. The bronchial system of the left basal segments was normal as was the pulmonary parenchyma on CT. Conclusion Characteristic CT findings consist of absence of the interlobar artery distal to the origin of the superior segmental artery and origination of an anomalous artery from the descending aorta that gives off branches to normal left basal segments. With a constellation of these CT findings, angiography would be obviated for definite diagnosis of this anomaly.

CT and MRI in detection of intrahepatic portosystemic shunts in patients with liver cirrhosis.

Objective Our goal was to determine the prevalence and anatomic location of intrahepatic portosystemic shunts (IPSs) in patients with hepatic cirrhosis as shown by CT and MRI. Materials and Methods We retrospectively reviewed CT and MR scans of 33 cirrhotic patients who had IPSs. In addition, two series of 100 consecutive CT or MR were reviewed to determine the prevalence of IPSs and the percentage of intrahepatic and extrahepatic paraumbilical veins. Results Intrahepatic portosystemic shunts were divided into three groups according to the intrahepatic course: paraumbilical shunt between the left portal vein and the paraumbilical vein anterior to the liver (n = 29); inferior vena caval shunt between the posterior branch of the right portal vein and the inferior vena cava (n = 2); and miscellaneous (n = 2). Shunts of the paraumbilical type ran through the medial (n = 23), lateral (n = 3), or both medial and lateral (n = 3) segments of the left lobe of the liver. Twenty-five patients had one shunt, and four had more than one. Six cases were also associated with extrahepatic paraumbilical veins. Conclusion Intrahepatic portosystemic shunts, especially the paraumbilical type, were not infrequently visualized in patients with hepatic cirrhosis.

Mature teratoma of the posterior mediastinum

Abstract. The vast majority of germ cell tumors in the thorax arise at or near the thymus. We report a case of a 41-year-old man with mature teratoma of the posterior mediastinum. He was asymptomatic and was incidentally found to have a posterior mediastinal mass. Computed tomography was helpful in suggesting a diagnosis of mature teratoma by demonstrating the presence of fat and calcification. The differential diagnosis included neurogenic tumors, liposarcoma, and extramedullary hematopoiesis.

Prenatal ultrasonic diagnosis of a case of Ellis–van Creveld syndrome with a single atrium

Abstract We present an infant with the lethal Ellis–van Creveld syndrome who was diagnosed prenatally from the sonographic detection of a narrow chest, postaxial hexadactyly of the hands and feet, short limbs and a single atrium. The postnatal radiographic features of the skeleton favoured the diagnosis of Verma-Naumoff type or Saldino-Noonan type short rib–polydactyly syndrome (SRPS). We discuss the criteria for the differential diagnosis of patients with SRPS, which can be difficult because of the overlap of the various phenotypes.

Diffusion-weighted MR imaging of Carmofur-induced leukoencephalopathy

Carmofur (1-hexylcarbamyl-5-fluorouracil), a derivative of 5-fluorouracil (5-FU), has been widely used in Japan as a postoperative adjuvant chemotherapy agent for colorectal and breast cancer. Periventricular hyperintensity on T2-weighted MR images in carmofur-induced leukoencephalopathy confront the physician with a broad range of differential diagnoses. We describe two cases of carmofur-induced leukoencephalopathy in which diffusion-weighted MR imaging revealed periventricular hyperintensity. We compared their findings with those of age-related periventricular hyperintensity in five patients and found discrepancies in signal intensity of periventricular areas. Our results suggest that diffusion-weighted MR imaging may be useful to differentiate carmofur-induced leukoencephalopathy from age-related periventricular hyperintensity.

Hyperattenuating insulinoma at unenhanced CT

Abstract. We report a case with insulinoma that showed higher attenuation than normal pancreatic parenchyma on precontrast CT. Pathology of the surgical specimen revealed the presence of psammoma bodies, which were responsible for hyperattenuation. It is worthwhile to obtain precontrast CT in patients suspected of having insulinoma.

Well-differentiated liposarcoma of the retroperitoneum with a fat–fluid level: US, CT, and MR appearance

Abstract. We report a case of retroperitoneal liposarcoma with a fat–fluid level that has not been previously described. A 36-year-old man presented with abdominal distension. Ultrasonography, CT, and MR imaging showed a tumor with a fat–fluid level; nondependent fluid was characteristic of fat. Liposarcoma should be included in the differential diagnosis of tumors exhibiting a fat–fluid level.