Hsu-Chong Yeh

Ultrasonography of adrenal masses: usual features.

Gray-scale B-scan was successful in delineating adrenal masses in 40 patients, all confirmed pathologically. Two patients with extra-adrenal pheochromocytomas, two calcified cysts, and two patients with bilateral adrenal hyperplasia are demonstrated. The usual ultrasonographic features are presented in this paper; they correlated well with urographic, angiographic, CT, and pathological findings. The smallest mass demonstrated was an aldosteronoma (1.3 cm in size).

Ultrasonography in ascites.

Ascites is usually not difficult to detect with ultrasonography because of its characteristic lack of echoes. However, minimal or lobulated collections of fluid or unusual distributions due to anatomical variations or associated pathological processes may create problems in diagnosis. Differentiation from an intraperitoneal abscess, hematoma, lymphocele, or cystic mass is of considerable clinical importance.

Ultrasonography of adrenal masses: unusual manifestations.

Forty patients with pathologically-proved adrenal masses, and two patients with extra-adrenal pheochromocytomas, were examined with gray scale B-scan. The authors describe unusual echo patterns of adrenal masses due to necrosis or hemorrhage, variations in the effects of large adrenal masses on surrounding organs and vessels, and the differential diagnosis. The complementary role of computed tomography is also discussed.

Visualization of the Thyroid Gland with Computed Tomography

Computed tomography of the neck will demonstrate the thyroid gland particularly well after contrast enhancement. Lucent nodules within the thyroid can be demonstrated, but the attenuation numbers are not reliable enough to distinguish cystic from solid lesions with current techniques because of partial volume effects and motion artifacts.

Ultrasonography and computed tomography in the diagnosis of homogeneous masses.

Ultrasonography can demonstrate the homogeneity, while CT can demonstrate the density of a mass lesion. If a mass appears echo-free at ultrasonography, but is denser than water at CT, a solid tumor with grossly uniform cellular structure (usually a lymphoma or sarcoma), or a hematoma or hemorrhagic cyst is likely. However, if the mass has water density at CT, a cystic lesion is confirmed. One case for each category is presented.

Ultrasonography of renal sinus lipomatosis.

Gray scale B-scans in renal sinus lipomatosis show a variety of features which must be differentiated from clinically significant pathological processes. Normal kidneys show dense homogeneous central echoes. In renal sinus lipomatosis, however, the central echoes are divided and become more sparse (Type I), interspersed with small relatively echo-free areas (Type II), or outline a single relatively echo-free area resembling a mass (Type III). In contrast to similar features in hydronephrosis or multiple cysts, the relatively echo-free areas in lipomatosis are ill-defined and do present several weak internal echoes.

Ultrasonography of the brachiocephalic arteries.

Sixteen patients with various lesions involving the brachiocephalic arteries were studied ultrasonographically. The examination was very useful in diagnosing aneurysms of the peripheral arteries and in differentiating an aneurysm from other causes of palpable pulsatile masses, such as a tortuous artery and tumor beneath an artery. The ultrasound technique used for evaluation of these lesions is described.

Complementary role of CT and ultrasonography in the diagnosis of desmoid tumor of abdominal wall

Abstract Seven desmoid tumors of anterior abdominal wall in three patients were scanned with ultrasound. These include one tumor in each of two patients and five tumors in another patient who had familial colonic polyposis (i.e. Gardners syndrome). The tumors were echo-free and sharply and smoothly defined simulating cysts. CT on the patient with multiple masses, however, showed the density of the masses to be that of soft tissue. Combined ultrasonography and CT, a homogeneous tumor of abdominal wall such as desmoid can be suggested.

Transjugular intrahepatic portosystemic shunt : correlation of portal vein velocity measurements and portosystemic pressure gradients

To assess the relationship between portal vein velocity measurements and portosystemic gradients, color Doppler sonography was performed on 12 patients before and after transjugular intrahepatic portosystemic shunt placement. An additional patient was examined before and after shunt modification. The average maximum portal vein velocity increased from 15.7 cm s-1 before shunt placement to 43.5 cm s-1 after shunt placement, while the average portosystemic gradient decreased from 22.0 mm Hg before shunt placement to 7.9 mm Hg after shunt placement. Flow was observed within the shunt in 11 of the 12 cases. Shunt velocity was measurable in nine patients, with an average value of 115.7 cm s-1. Reversal of intrahepatic portal vein flow was observed in 10 cases following shunt placement. Color Doppler sonography is a useful non-invasive tool in the evaluation of intrahepatic portosystemic shunts, and changes in portal vein velocity correlate well with changes in the portosystemic gradient.

A Pulmonary Venous Indentation on the Esophagus—A Normal Variant

An extrinsic indentation on the anterior left wall of the esophagus, about 4-5 cm below the carina, is a relatively common finding and should be considered a normal variant, although rarely it may be due to an aberrant insertion of a pulmonary vein into the left atrium. The indentation is best seen in a steep left posterior oblique horizontal position. In most cases it is caused by pressure of the left inferior pulmonary vein or a common confluence of the left pulmonary veins near the insertion into the left atrium. Generally, it does not cause any symptoms and should not be mistaken for a mediastinal mass.