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Biomedical subjects

D K Heaston

Publications and source records attributed to D K Heaston.

At least 19 recordsLinked to original sources

Percutaneous dilation of benign biliary strictures.

Percutaneous balloon dilation of benign biliary strictures was successful in 15 of 18 patients in whom the procedure was attempted. Successful dilation was achieved in nine of 11 patients who had biliary enteric strictures, with follow-up of 22-55 months (mean, 35.4 months) after catheter removal in seven patients. Five of six strictures in the biliary tree that developed after surgery were successfully dilated, with long-term follow-up available in two patients (58 and 42 months). A patient with an inflammatory common bile duct stricture that was successfully dilated was followed up for 18 months. Percutaneous dilation of biliary tract strictures is a promising technique with good long-term results and may be the initial treatment of choice in biliary stricture management.

Catheterization

CT differentiation of thoracic aortic aneurysms from pulmonary masses adjacent to the mediastinum.

Paramediastinal masses adjacent to the aorta require a diagnostic evaluation to differentiate between tumor and aneurysm. It has been suggested that neoplasm may enhance sufficiently to be confused with a vascular structure or that a clot filled aneurysm may simulate a neoplasm by not filling with contrast medium. Five patients, two with thoracic aneurysms, two with malignancy, and one with a malignancy and an aortic dissection, are presented in whom bolus injection computed tomography (CT) was able to distinguish between aneurysm and mass. The CT examination also accurately visualized the point of communication of the aneurysm with the aorta, defined the relationship of the aneurysm to vital mediastinal structures for planning surgical resection, and helped plan the approach for percutaneous transthoracic needle aspiration when tumor was suspected. Bolus injection CT represents a rational alternative to aortography for mediastinal paraaortic masses.

Adult

Diagnosis of lithokelyphos by computed tomography.

An incidental stone child, lithokelyphos, presented as an undiagnosed abdominal mass in a woman with cervical cancer. Lithopedion formation is an uncommon result of an abdominal pregnancy. The types of lithopedions as well as their method of formation and clinical features are reviewed. In addition, the computed tomographic features of lithopedions are presented.

Adenocarcinoma

Solitary pulmonary metastases in high-risk melanoma patients: a prospective comparison of conventional and computed tomography.

A prospective comparison of chest radiography, conventional tomography, and computed tomography (CT) in the detection or confirmation of solitary pulmonary nodules was made in 42 patients with high propensity for pulmonary metastases due to advanced local (Clark level IV or V) or regional malignant melanoma. Unequivocal nodules were revealed by chest radiography in 11 patients, conventional tomography in 16, and computed tomography in 20 patients. Both plain films and tomography in three of these 20 were normal, but follow-up verified pulmonary metastases. Computed tomography detected more pulmonary nodules than conventional tomography in 11 patients in addition to identifying lesions in extrapulmonary sites. Therefore, chest CT is recommended before institution of immunotherapy or surgical removal of a solitary pulmonary melanoma metastasis. Once chemotherapy had been instituted for bulky regional or cutaneous involvement, however, the findings of either conventional or computed tomography were comparable in this study.

Adult

Age-related changes in the thymus gland: CT-pathologic correlation.

Recent reports suggest that computed tomography (CT) is useful for thymoma detection in patients with myasthenia gravis. However, that usefulness may be conditioned by the state of the normal thymus. To examine this concept, the CT findings in 64 consecutive patients with histologic confirmation of thymic status after thymectomy or thymic biopsy during mediastinal exploration were reviewed. The normal thymus has a bilobed, arrowhead-shaped cross section at all ages, with gradual focal or diffuse fatty infiltration of the parenchyma usually occurring between 20 and 40 years of age. A thymoma is usually a spherical or oval mass, often producing a focal, distinct bulge in the adjacent pleural reflection. The differentiation of thymoma from normal thymus should be possible in most patients if age-related changes in the normal gland are appreciated.

Adolescent

Transluminal angioplasty of the superior mesenteric artery: an alternative to surgical revascularization.

Percutaneous transluminal angioplasty of stenotic lesions of the superior mesenteric artery was performed eight times in four patients with ischemic bowel syndrome. All patients were either poor surgical risks or had lesions not amenable to surgical correction. One patient also had angioplasty of a stenotic celiac artery. The four patients in this report have had more than 1 year of follow-up. All have had good results. Superior mesenteric artery angioplasty seems to be a nonsurgical alternative for the treatment of atherosclerotic mesenteric ischemia.

Adult

The pelvis after surgery for rectal carcinoma: serial CT observations with emphasis on nonneoplastic features.

Ten asymptomatic patients who had undergone resection of rectal carcinoma were evaluated prospectively by at least three serial computed tomographic (CT) examinations of the pelvis within 24 months of surgery. Of the seven patients who had undergone abdominoperineal resection, five were found to have a presacral mass due to normal postoperative changes within the first 4 months. The mass showed a variable diminution between 4 and 9 months after operation and developed a more distinct outline, partial separation from the sacrum, or a change in configuration to a thin transverse sliver. These changes indicate the possibility of CT differentiation of a normal postoperative mass from local recurrence. In the other five patients, no postoperative mass was observed. In one patient CT demonstrated a solitary 1.5 cm lymph node metastasis. This patient was asymptomatic and had a normal carcinoembryonic antigen level. From these observations, a baseline CT study of the pelvis within 2-4 months of resection of rectal carcinoma, followed by serial CT examinations at about 6-month intervals is recommended for the detection of early asymptomatic pelvic recurrence and to facilitate differentiation from persistent postoperative changes.

Carcinoma

Closed-system venography in the evaluation of angiodysplastic lesions of the extremities.

Closed-system venography is a minimally invasive, well tolerated method for diagnosing and delineating extremity angiodysplastic lesions. This method involves passive filling of the vascular tree after compressive exsanguination of an extremity and extrinsic occlusion of its arterial supply and venous drainage, thereby creating a static, closed system. Closed-system venography was done in 17 patients, where it correctly identified 11 of 12 surgically confirmed vascular abnormalities. There were no false-positive examinations. Whereas ateriography remains the examination of choice in studying arteriovenous malformations, closed-system venography has demonstrated a superior ability to diagnose and define lesions of capillary and venous origin.

Adolescent

Recurrent rectal carcinoma in an asymptomatic patient.

Pelvic recurrence is a common cause of symptoms and mortality in patients who have undergone surgical resection of rectal carcinoma. Diagnosis by physical examination and standard radiologic techniques is usually only possible when the recurrence becomes symptomatic because of its advanced state. Previous reports have documented the ability of computed tomography (CT) to depict accurately pelvic recurrence of rectal carcinoma in the symptomatic patient. Surgical resection of recurrence is usually noncurative but appears to result in a more prolonged survival if performed in the asymptomatic patient. We report a case of pelvic lymph node recurrence suggested by CT and confirmed by CT guided needle biopsy in an asymptomatic patient. Diagnosis of recurrence at this early stage by CT, supplemented with CT guided biopsy, may offer the patient an increased chance of survival following surgical resection.

Adenocarcinoma

CT demonstration of subcutaneous venous collaterals.

Subcutaneous collateral veins were identified by computed tomography (CT) in 12 patients. These were seen as enhancing round or tubular structures surrounded by subcutaneous fat, and most were associated with occlusion of a major vein in the abdomen or thorax. The CT appearance of deep vein occlusions included an intraluminal thrombus with an enhancing rim, a mass replacing the nonvisualized vein and distortion of the vein by an adjacent mass. The subcutaneous fat was examined on the CT scans of 50 patients not suspected of having deep venous occlusions. The appearance of normal subcutaneous structures and the differential diagnosis are discussed.

Collateral Circulation

Study of safety and tolerance of iopamidol in peripheral arteriography.

Iopamidol, a non-ionic contrast agent, was evaluated during peripheral arteriography in 10 patients. All reported a sensation of warmth during injection. One described the procedure as moderately painful. All objectively tolerated the injections well, and there were no significant changes in clinical or laboratory findings. Vessel opacification was good to excellent in all cases. The authors suggest that non-ionic contrast agents replace ionic agents for peripheral arteriography.

Aged

Volume determinations using computed tomography.

Computed tomography potentially offers the most accurate noninvasive means of estimating in vivo volumes. Contiguous 1-cm-thick CT scans were obtained through phantoms, dog kidneys in vivo, and human spleens before splenectomy. Cross-sectional areas were calculated for each individual scan and volumes then determined with each of four mathematical integration techniques. Volume estimations were compared to volumes determined by water displacement. The simplest, most practical means of calculating volumes, using the summation-of-areas technique with scans obtained at 2 cm intervals, was similar in accuracy to more complex methods. The mean percentage error of volume calculations using the sum-of-areas technique was 4.95% for five immobile phantoms, 3.86% for eight dog kidneys, 3.59% for eight human spleens in vivo at 1 cm scan spacing, and 3.65% for the same human spleens at 2 cm scan spacings. Difficulties in visual recognition and manual tracking of object boundaries seem to be more significant sources of error than patient-related factors.

Animals