Prostate visualization studies in males homozygous and heterozygous for 5 alpha-reductase deficiency.

Male pseudohermaphrodites with 5 alpha-reductase deficiency have ambiguous genitalia and nonpalpable prostates on rectal examination, suggesting the dihydrotestosterone dependency of these structures. To clearly delineate the status of the prostate, male pseudohermaphrodites with 5 alpha-reductase deficiency had transrectal sonography of the prostate performed, and the results were compared to that of age-matched male controls. In six male pseudohermaphrodites, magnetic resonance imaging studies of the prostate were also performed. Heterozygote fathers also had transrectal sonography of the prostate performed and the results compared to age-matched controls. The prostates of the male pseudohermaphrodites appeared as platelike soft tissue structures posterior to the urethra on both prostatic ultrasound and magnetic resonance imaging. Prostatic volume, as determined on prostatic ultrasound by two different methods, was significantly smaller (approximately one-tenth) than the volume of age-matched controls. Transurethral ultrasound guided biopsy of the prostate in two affected subjects revealed stromal tissue. These results correlate with undetectable prostate-specific antigen in affected subjects, suggesting atrophic epithelium or lack of epithelial differentiation. This study demonstrates the dihydrotestosterone dependence of the prostate for normal differentiation and growth. The presence of some prostatic tissue in the male pseudohermaphrodites may be due to the fact that there is a decrease and not an absence of 5 alpha-reductase activity, and/or that the increased level of testosterone in subjects with this condition partially compensates for the decreased level of dihydrotestosterone. There was no difference, however, in prostate size between heterozygous fathers and age-matched control males. The heterozygote fathers had dihydrotestosterone production sufficient for normal prostate growth and development.

Adrenal hemorrhage and renal vein thrombosis in the newborn: MR imaging.

Three newborn infants with flank masses underwent magnetic resonance (MR) imaging after ultrasound (US) indicated adrenal hemorrhage and/or renal vein and inferior vena cava thrombosis. MR imaging was valuable in defining the hemorrhagic nature of echogenic and hypoechoic suprarenal masses and in delineating thrombi within the renal veins and inferior vena cava. Two infants with renal parenchymal damage had abnormal radionuclide scans and abnormal corticomedullary distinction on MR images. The major role of MR imaging may be in the early course of these conditions, when added diagnostic specificity is likely to affect patient management. In most instances, size of hemorrhage and intravenous clots, as well as renal size, may be accurately followed with US, while radionuclide scanning remains necessary for evaluation of renal functional impairment.

Intraoperative sonography: application in renal cell carcinoma.

Our ability to detect and potentially to treat renal tumors earlier has increased exponentially during recent years, in part owing to the introduction of more sophisticated imaging modalities. We report 2 cases in which intraoperative sonography was used to localize tumors not palpable at operation. In both cases surgery was performed on solitary kidneys for renal cell carcinoma in otherwise healthy patients.

MR imaging of portal venous thrombosis: correlation with CT and sonography.

Fourteen patients with portal venous thrombosis (PVT) diagnosed by CT and/or sonography were studied with MR. Three of the 14 had portal hypertension. The MR findings were compared with those of eight patients with portal hypertension, but without CT or sonographic evidence of PVT. MR imaging showed portal venous thrombosis in all 14 PVT cases. Intraluminal thrombi of less than 5 weeks duration appeared markedly hyperintense relative to liver and muscle on both T1- and T2-weighted images. Older thrombi appeared hyperintense relative to liver and muscle in eight of 11 cases, but only on T2-weighted images. MR showed thrombi in 11% more portal vessels than did CT (MR = 30, CT = 27) and in 28% more vessels than did sonography (MR = 32, sonography = 25). MR also showed 24% more collateral vessels than did CT (MR = 31, CT = 25) and 50% more vessels than did sonography (MR = 33, sonography = 22). Third-echo images (echo time = 96 msec, repetition time = 1500-2150 msec) verified the presence of venous thrombi in 28 (93%) of 30 PVT vessels, and they differentiated flow-related intravascular signal from true thrombi in six (17%) of 36 portal hypertension vessels. We conclude that MR is a valuable tool for imaging portal vein thrombosis. MR is a good substitute for CT and can be more informative than sonography.

Computed tomography and magnetic resonance imaging of a superior gluteal artery pseudoaneurysm.

The magnetic resonance and computed tomography appearances of a superior gluteal artery pseudoaneurysm are described, with emphasis on the relative advantages and disadvantages of these two imaging procedures.

Perirenal spaces: CT evidence for communication across the midline.

The perirenal spaces may communicate across the midline, anterior to the lower aorta and vena cava. The connecting channel has a relatively narrow anteroposterior dimension on computed tomographic (CT) scans, both in vivo and in injected cadavers. It may therefore be difficult to visualize on abdominal radiographs and may be mistaken for unopacified bowel on CT scans. The midline extension of perirenal fluid is usually contiguous to the lower abdominal great vessels anteriorly but does not surround them completely, possibly because of fibrous septa within the perivascular fat. Hematomas from ruptured aortic aneurysms extend mainly into the perirenal spaces. Thus, the lower abdominal great vessels are located, in effect, within the midline extension of these spaces. Superiorly, the perirenal spaces extend to the diaphragm, abutting the lateral and anterior margins of the psoas and quadratus lumborum muscles and the bare area of the liver. Inferiorly, perirenal collections appear to diverge into the pelvis, along the psoas muscles, ureters, and iliac vessels.

Computed tomography appearance of adrenal vein thrombosis.

The computed tomography appearance of adrenal hemorrhage secondary to adrenal vein thrombosis is illustrated. The lesion appeared radiolucent, with a small focal calcification, mimicking an adrenal adenoma. Hypercoagulopathy was an underlying factor in this patient with myelofibrosis and chronic myelogenous leukemia.

Computed tomography of renal aspergillosis.

The CT and sonographic findings of a case of localized, invasive aspergillosis of the kidney are presented.

CT of fibrous tissues and tumors with sonographic correlation.

Fibrous tissues and tumors may appear hyperdense relative to muscles and solid viscera on CT both before and after IV contrast injection. In addition, fibrous tissues generally have a homogeneously hypoechoic sonographic appearance. The diagnostic value of these criteria is illustrated in a group of 21 fibrous tissue abnormalities that includes retroperitoneal, mediastinal, and perigraft fibrosis, sclerosing pseudotumor of the orbit, generalized fibromatosis, desmoids, malignant fibrous histiocytoma, and normal tendons and ligaments. It is concluded that while hyperdensity on CT and echopenia on sonography are not pathognomonic of fibrous tissue, they occur with sufficient frequency that their presence raises the possibility of a fibrous lesion.

Intraperitoneal paravesical spaces: CT delineation with US correlation.

The urinary bladder, obliterated umbilical arteries, and inferior epigastric vessels located within the extraperitoneal space of the anterior abdominal wall indent the anterior parietal peritoneum, forming intraperitoneal paravesical fossae. These are the supravesical space and the medial and lateral inguinal fossae. More posteriorly, the peritoneum covering the bladder is reflected onto the rectum to form the rectovesical space, which is divided by the uterus into an anterior vesicouterine recess and a posterior rectouterine pouch, or cul-de-sac. The cul-de-sac is continuous with the pararectal and ovarian fossae and is bounded posterolaterally by the rectouterine (sacrogenital) folds. These peritoneal compartments form a large potential space for the accumulation of ascites and are separated from the equally large extraperitoneal paravesical spaces by only a thin layer of peritoneum or peritoneum and umbilicovesical fascia. The computed tomographic scans of 100 patients with ascites were reviewed, with particular attention to the differentiation between intraperitoneal and extraperitoneal paravesical collections. The scans of intraperitoneal collections were found to have certain characteristic appearances, including inferior displacement of the distended urinary bladder, visualization of the umbilical folds, and preservation of the preperitoneal fat.

Adrenal hemangioma: a case report.

Adrenal hemangioma is a very rare tumor. Presented is the 18th case proved by autopsy or surgery reported in world literature. The tumor was incidentally discovered at autopsy. Unless this tumor has characteristic calcifications, phlebolith or phlebolithlike, its computed tomography appearance is nonspecific. Therefore, by computed tomography this tumor cannot be differentiated from other primary or secondary adrenal tumors.

Computed tomography, sonography, and MR imaging of abdominal tuberculosis.

The CT, sonographic, and magnetic resonance findings of a case of abdominal tuberculosis are presented. A diffusely thickened, enhanced peritoneum was imaged best on CT. Sonography was the only imaging modality to demonstrate septations within the tuberculous ascites. Magnetic resonance contributed no additional information.

Computed tomography, sonography, vesiculography, and MR imaging of a seminal vesicle cyst.

A case of crossed ectopia of seminal vesicle cyst is reported. Magnetic resonance (MR) appearance of the seminal vesicle cyst is described first. Brief review of the literature for the seminal vesicle cyst is made and role of new imaging modalities including ultrasound, CT, and MR is discussed.

The portacaval space: CT with MR correlation.

Between the portal vein and the inferior vena cava lies a small space that may be occupied by multiple anatomic structures including the caudate and papillary processes of the caudate lobe of the liver, portacaval lymph nodes, replaced or accessory right hepatic arteries, posterosuperior pancreaticoduodenal vessels, the cystic duct, and the epiploic foramen to the lesser sac. The sectional anatomy of these structures is illustrated in this paper with particular emphasis on the portacaval nodes. Unlike the adjacent celiac lymph nodes, portacaval nodes appear rectangular or elliptical on transverse sections and may measure up to 1.3 cm in anteroposterior dimension. They may mimic portions of the pancreas, liver, or biliary tract on sectional images.

Posterior peritoneal recesses: assessment using CT.

Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces, and particularly their appearance on computed tomographic scans, are illustrated in this paper.

The oblique coronal view in sonography of the retroperitoneum.

The abdominal aorta and inferior vena cava can be seen easily from the right flank on a longitudinal coronal-oblique sonogram, using the liver as an acoustic window. With this view, tortuosity of the abdominal aorta can be shown, just as it appears on frontal aortography in 70% of cases, and similar to aortography in 27% of cases. The proximal renal and common iliac arteries can be demonstrated in 73% and 82% of cases, respectively, when aneurysms are absent, and in 45% and 82% of patients when aortic aneurysms are present. Enlarged posterior abdominal lymph nodes may be detected with accuracy, sensitivity, and specificity of 90% when compared to computed tomography (CT). Prominent gonadal vessels and anomalous or duplicated venae cavae can be displayed longitudinally, just as they might appear on venography. The coronal oblique view from the right flank, and occasionally from the left flank, can be a valuable addition to the standard views obtained during abdominal sonography. It is also a valuable supplement to CT in the differentiation of paraaortic vessels from enlarged lymph nodes.

Aortic aneurysm secondary to umbilical artery catheterization.

A 14-month-girl presented with an asymptomatic posterior mediastinal mass. She had a history of prematurity, umbilical artery catheterization, and sepsis. The diagnosis of aortic aneurysm was made by dynamic computed tomography. The aneurysm was successfully resected.

MR, CT, and ultrasonographic demonstration of splenic vein thrombosis.

The first case report of magnetic resonance imaging of splenic vein thrombosis is presented together with CT and ultrasound correlation.

Accessory fissures of the liver: CT and sonographic appearance.

Invaginations of the liver by the diaphragm form accessory fissures that may mimic the major hepatic fissures on sectional images. Accessory fissures are most common in the superior right hepatic lobe. Their average incidence on computed tomographic (CT) scans is 25%. Their frequency increases with age, approaching 70% in the seventh and eighth decades. Their depth may equal or exceed 2 cm in one-third of cases. Multiple accessory fissures may mimic pathologic liver nodules on CT and may be associated with diaphragmatic scalloping or eventration on the chest film. When only parts of these fissures are seen sonographically, they may be mistaken for echogenic liver lesions. The differentiation of accessory fissures from the major hepatic fissures, from pathologic lesions, and from sonographic pseudofissure artifacts is discussed.

CT of the hyperdense renal cyst: sonographic correlation.

The computed tomographic (CT) appearances of 19 hyperdense renal cysts in nine patients are reported. Sixteen of these cysts were found over a period of only 1 year with state-of-the-art CT equipment. Hyperdense renal cysts are probably more common than suggested by case reports. Their rate of detection can be expected to increase with the wider availability of fast CT scanners using thin collimation. A CT diagnosis of benign hyperdense renal cyst can be made if a lesion meets all of the following criteria: (1) smoothly outlined imperceptible wall with sharp demarcation from the kidney; (2) before intravenous contrast injection, homogeneous internal content with CT numbers 40%-240% higher (70%-240% higher for lesions 10 mm or more in diameter) than renal parenchyma; and (3) after intravenous contrast injection, persistent internal homogeneity and insignificant enhancement (less than 6%) relative to normal renal cortex. For masses exceeding 15 mm in diameter, sonography can be a valuable confirmatory test.