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Biomedical subjects

P A Randall

Publications and source records attributed to P A Randall.

At least 19 recordsLinked to original sources
PubMed1993

MR imaging in the evaluation of the chest after uncomplicated median sternotomy.

Although complications of median sternotomy are infrequent, they are associated with high morbidity and mortality. Current imaging modalities have proved to be of limited value in the evaluation of these abnormalities. The search for more efficacious means of assessment is continual. The appearance of the thorax was evaluated in 10 patients who were undergoing median sternotomy for coronary artery bypass graft surgery. Three serial magnetic resonance (MR) imaging examinations were performed on each patient. These examinations included a baseline preoperative study and two postoperative studies. Each patient included in the study had an uncomplicated postoperative clinical course. Usual postoperative findings included pleural effusions, pulmonary parenchymal abnormalities, mediastinal edema, and pericardial effusions. On the basis of this limited study, the authors believe that MR imaging is a feasible means of evaluating the chest after surgery. An appreciation of the normal postoperative appearance is essential before complications can be reliably identified and characterized.

Artifacts↗
PubMed1991

Developmental lymphatic disorders of the thorax.

Developmental disorders that involve the lymphatic channels of the thorax, although rare, are important and must be distinguished from the more common causes of chest masses or diffuse lung disease. There are four major types of developmental lymphatic disorders that affect the thorax: lymphangiectasis, characterized by congenital anomalous dilatation of pulmonary lymph vessels; localized lymphangioma, a rare and benign, usually cystic, lesion characterized by masslike proliferation of lymph vessels; diffuse lymphangioma, a proliferation of vascular, mainly lymphatic, spaces in which visceral and skeletal involvement are common; and lymphangioleiomyoma, which involves a haphazard proliferation of smooth muscle in the lungs and dilatation of lymphatic spaces. These characteristic findings can be seen with radiographic studies as well as with histologic evaluation. The discovery of one of these lymphatic disorders may prompt an investigation for associated congenital anomalies, including Noonan syndrome, asplenia, Gorham syndrome, and tuberous sclerosis.

Child↗
PubMed1990

Calcified hilar and mediastinal lymph nodes in an AIDS patient with Pneumocystis carinii infection.

An unusual radiologic manifestation of Pneumocystis carinii infection (enlarged, calcified hilar and mediastinal lymph nodes) in a patient with acquired immunodeficiency syndrome is described. This atypical manifestation caused significant diagnostic confusion. Recognition that P carinii infection can cause calcification of hilar and mediastinal lymph nodes may prevent this confusion and facilitate diagnosis and treatment.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Pulmonary arterial hypertension: a contemporary review.

Pulmonary arterial hypertension has many causes, only some of which are well understood. The radiographic findings in pulmonary arterial hypertension are very similar regardless of the cause. Some radiographic features such as cardiac chamber enlargement, occur secondary to elevation of pulmonary pressures. In addition, sequential radiographs may demonstrate dramatic changes as the hypertension develops. This article presents examples of the various forms of pulmonary arterial hypertension, with pathologic correlation. Included are chronic pulmonary thromboembolism, plexogenic pulmonary arteriopathy, pulmonary venooclusive disease and persistent fetal circulation. Examples of lesions causing secondary pulmonary arterial hypertension: parenchymal lung disease, pulmonary venous hypertension, and congenital heart disease, are also illustrated.

Diagnostic Imaging↗
PubMed1988

Radiographic appearances of the St. Jude Medical Valve.

The St. Jude Medical Valve (SJMV), one of the more popular prosthetic cardiac valves in use today, has been described as poorly visualized on plain radiographs, being visible only at fluoroscopy. The chest radiographs of 76 patients (85 valves) in whom the SJMV had been implanted were reviewed in order to assess the visibility and appearances of the SJMV. We found that the SJMV was visible postoperatively in 70 of the 76 patients (92%) on either frontal or lateral chest radiographs or both. Knowing the various normal appearances of the SJMV described here and the anatomic locations of the heart valves, radiologists should be able to visualize and identify this prosthetic valve on chest radiographs in the majority of patients.

Female↗
PubMed1988

Composite graft replacement of the ascending aorta and aortic valve. Late follow-up with intra-arterial digital subtraction angiography.

Between 1979 and 1986, 30 patients underwent replacement of the aortic valve and ascending aorta by a composite graft, with aortic wrapping of the graft. Thirteen patients had annuloaortic ectasia; six had DeBakey type I dissection (five acute, one chronic); three had DeBakey type II dissection (one acute, two chronic); three had left ventricular-aortic discontinuity caused by prosthetic valve endocarditis; three had sinus of Valsalva aneurysms after previous aortic valve procedures; and two had atherosclerotic aneurysms. Three patients died (10%). The mean duration of follow-up was 54 months. Fifteen patients consented to be restudied by intra-arterial digital subtraction angiography; studies were performed 6 to 58 months (mean 25 months) after composite graft replacement. Two patients had pseudoaneurysms at the right coronary anastomosis, which were repaired successfully. One patient showed persistent dissection beyond the distal aortic anastomosis; no reoperation has been done. One patient had pulmonary edema. Emergency study and reoperation showed disruption of the proximal aortic anastomosis and right coronary anastomosis. Anastomotic dehiscence after composite graft replacement is potentially lethal. Follow-up by means of intra-arterial digital subtraction angiography is simple and highly accurate. We suggest that dehiscences may occur early in the postoperative period and that restudy may be appropriate within a few months after operation.

Angiography↗
PubMed1987

Chest tube tracks.

Chest tube tracks may simulate normal structures or pathology. This article will help the radiologist to understand their formation and to recognize them as iatrogenic shadows.

Humans↗
PubMed1987

The continuum of pulmonary developmental anomalies.

The classic features of six common pulmonary developmental anomalies have been presented. In addition, several overlap cases, each demonstrating features of more than one anomaly, have been illustrated. Such cases serve to emphasize that pulmonary developmental anomalies exist as a continuum, often frustrating our attempts at discrete classification. Future advances in pulmonary embryology may further elucidate the pathogenesis of these entities.

Adult↗
PubMed1983

Complete extra-anatomic bypass of the aortic root: treatment of recurrent mediastinal infection.

A 45-year-old woman underwent complete extra-anatomic bypass of the aortic root for recurrent mediastinal infection. Operative repair consisted of removal of an aortic valve prosthesis and an ascending aortic graft. The aortic root and transverse aortic arch were closed primarily and a valved conduit was placed from the left ventricular apex to the descending aorta. Coronary flow was reestablished with saphenous vein grafts taken from the innominate and subclavian arteries to the coronary artery orifices. Infection did not recur, but the patient died 9 months following operation apparently of right coronary artery graft occlusion.

Aorta↗
PubMed1980

Mild hypothermia: its effect on cardiac output and regional perfusion in the neonatal piglet.

Cardiac output and regional perfusion was measured in neonatal piglets using radionuclide labeled microspheres. Measurements made at normal core body temperature (38-39.5 degrees C) were compared to those obtained after a 4-5 degrees C reduction in temperature. There is a significant reduction in cardiac output and in the myocardial, renal, pancreatic, and adrenal blood flow. The separated layers of the gastrointestinal tract wall are subject to varying decreases in blood flow. The mucosa of the distal small intestine demonstrated the most significant decreases in blood flow during mild hypothermia.

Animals↗
PubMed1980

Vascular dysgenesis associated with skeletal dysplasia of the lower limb.

Three patients who had shortening or absence of the fibula were evaluated angiographically. An abnormal arterial pattern was found in all of the dysplastic limbs. This abnormality was characterized by persistence of an embryonic vascular pattern, absence of one of the normal arteries, and failure of formation of the plantar arch. In each patient there was a large posterior artery in the leg, termed the tibialis posterior superficialis.

Arteries↗
PubMed1979

Failure of prostaglandins E1 and E2 to alter canine gastric mucosal cyclic nucleotides.

The action of prostaglandins and indomethacin on gastric mucosal cyclic nucleotide concentrations was evaluated in 18 anesthetized mongrel dogs. Prostaglandins E1 (PGE1) and E2 (PGE2) (25 microgram/kg bolus, then 2 micrograms/kg/min) were administered both intravenously (4 experiments; femoral vein) and directly into the gastric mucosal circulation (10 experiments; superior mesenteric artery). The possible synergistic effect of pre-treatment and continuous arterial infusion of indomethacin (5 mg/kg bolus for 5 min, then 5 mg/min), a prostaglandin synthetase inhibitor, with PGE2 was studied in 4 experiments. Antral and fundic mucosa were biopsied and measured by radioimmunoassay for cyclic nucleotides. Doses of PGE1 and PGE2 which inhibited histamine-stimulated canine gastric acid secretion did not significantly alter antral or fundic mucosal cyclic nucleotide concentrations. Concomitant infusion of PGE2 with indomethacin did not potentiate the mucosal nucleotide response compared to PGE2 alone. These studies fail to implicate cyclic nucleotides as mediators of the inhibitory acid response response induced by PGE1 or PGE2 in intact dog stomach.

Animals↗
PubMed1979

Arteria magna revisited.

Arteria magna has been described pathologically in the literature as a peculiar and unique form of atherosclerosis. The authors offer an alternative hypothesis, based on results of angiographic studies with pathologic correlation in 18 patients with arteria magna. The findings indicate that this vascular entity might be more accurately described as a loss of the medial elastica with subsequent vessel enlargement both in length and diameter.

Adult↗