PubMed Health⌕ Search

Biomedical subjects

R B Dyer

Publications and source records attributed to R B Dyer.

96 records · Page 6Linked to original sources
PubMedDate not supplied

Percutaneous transcatheter renal ablation with absolute ethanol for uncontrolled hypertension or nephrotic syndrome: results in 11 patients with end-stage renal disease.

PURPOSE: Retrospective review of authors' experience with percutaneous transcatheter renal ablation in patients with uncontrolled hypertension and/or nephrotic syndrome. MATERIALS AND METHODS: Between April 1987 and September 1995, renal ablation was performed on 11 patients aged 10 months to 21 years. All patients had end-stage renal disease (ESRD) with uncontrolled hypertension (10 patients) and/or nephrotic syndrome (four patients). Uncontrolled hypertension was defined as diastolic pressure greater than 90 mm Hg despite multidrug antihypertensive therapy. Nephrotic syndrome was defined as proteinuria exceeding 960 mg/m2 per day, serum albumin level less than 3 g/dL, and generalized edema. Embolization was performed with absolute ethanol from a common femoral artery approach. In most cases, a balloon catheter was used to prevent alcohol reflux into the aorta or nontarget renal artery branches, such as the adrenal arteries. Angiographic stasis of contrast material in the renal arteries was the endpoint. RESULTS: All patients experienced a postembolization syndrome of 3-5 days duration, clinically manifested by variable degrees of nausea, vomiting, fever, and pain. Long-term improvement in hypertension was observed in nine patients. Improvement in hypertension was defined as diastolic blood pressure below 90 mm Hg while the patient received the same or fewer antihypertensive medications. The four patients with nephrotic syndrome were cured of their proteinuria and edema. CONCLUSIONS: Transarterial renal ablation with alcohol is efficacious for treatment of uncontrolled hypertension and nephrotic syndrome in patients with ESRD. The morbidity and mortality in our series were less than those reported for surgical nephrectomy.

Adolescent↗
PubMedDate not supplied

Computed tomography of primary renal osteosarcoma.

Primary renal osteosarcoma, a rare malignancy, was diagnosed preoperatively based on its unusual imaging features. The CT demonstration of a peripherally located renal mass containing ossification suggests the diagnosis of renal osteosarcoma. This diagnosis is clinically significant due to the poor prognosis of patients with this tumor even when surgically resectable.

Female↗
PubMedDate not supplied

Overview of traumatic injury of the thoracic aorta.

Traumatic injury of the thoracic aorta is a major clinical concern in patients who sustain deceleration or crush injuries. Several mechanical factors may explain the typical locations of thoracic aortic rupture (aortic isthmus, ascending aorta). Understanding these factors and the pathophysiology involved helps the radiologist to recognize aortic trauma at various imaging examinations. Chest radiography is the initial screening examination, and radiographs are evaluated specifically for signs of mediastinal hematoma, an indication of significant thoracic trauma. The most important of these signs include loss of aortic contour, tracheal deviation, ratio of mediastinal width to chest width, deviation of a nasogastric tube to the right of the T-4 spinous process, and depression of the left main-stem bronchus (> 40 degrees below the horizontal). Computed tomography (CT) is used increasingly when results of chest radiography are equivocal. CT can clearly demonstrate mediastinal hematoma, but this finding is also mimicked by several entities, including atelectatic lung, thymus, and pericardial recesses. Aortography is the standard for diagnosis. Traumatic aortic injury is treated urgently with surgical repair. The rare patient who survives aortic injury without surgery may develop a chronic pseudoaneurysm.

Algorithms↗
PubMedDate not supplied

Abnormal calcifications in the urinary tract.

A wide variety of calcifications may develop in the urinary tract. Calculi, the most common form of urinary tract calcification, are usually radiopaque due to their calcium content, whereas cystine stones tend to be less opaque. In cortical nephrocalcinosis, calcification may be spotty or may appear as a thin rim outlining the cortex. Intracystic calcification is usually thin and peripheral and is often described as having an "eggshell" appearance. In renal masses, pure central calcification usually indicates malignancy, although malignancy may also be present with pure peripheral calcification. An incomplete ring of calcification seen over the central portion of the kidney should suggest the presence of an abnormal vascular structure. A sloughed papilla may lead to calcification that is usually triangular or ring-shaped or has a broken rim pattern. Ureteral calculi usually have a uniform radiopacity, whereas phleboliths are often less opaque centrally. Like renal calculi, bladder calculi usually contain a calcium component; they may be laminated, faceted, spiculated, or seedlike in appearance. Urachal carcinoma is commonly associated with tumor calcification, which typically occurs at the dome of the bladder. Schistosomiasis of the bladder may produce mural calcification with a typical thin arcuate pattern and may be associated with calcification in other portions of the urinary tract. Although urinary tract calcifications may be difficult to characterize specifically, they can be classified according to location, appearance, and relation to various pathologic conditions.

Calcinosis↗
PubMedDate not supplied

Locating the kidneys on CT to guide nephrotomography.

Tomography of the kidneys is a routine procedure performed during intravenous urography. Precisely locating the kidneys, however, can be difficult. This article describes a study performed to determine a simple and accurate measurement for kidney location as a guide to obtaining initial nephrotomographic sections. The authors measured the distance from the midplane of the kidney to the posterior skin line on abdominal CT images in 26 patients. This distance averaged one-third the thickness of the abdominal region. The best depth for the nephrotomographic cut was found to be one-third the thickness of the abdomen plus the thickness of any table pad.

Female↗