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Biomedical subjects

P B Harrison

Publications and source records attributed to P B Harrison.

29 records · Page 2Linked to original sources
PubMed1989

Color flow duplex screening of infrainguinal grafts combining low- and high-velocity criteria.

The aim of this prospective study was to evaluate the ability of duplex ultrasonography to identify infrainguinal grafts at high risk for failure. The criteria used identified low flow by low peak systolic velocity (less than 45 cm/s) and stenosis by high velocity (greater than 300 cm/s) or by velocity at the stenosis three times the velocity in the adjacent normal graft. A total of 114 patent grafts were scanned and compared with concurrent angiograms. Duplex scanning correctly identified 18 high-risk grafts by low-flow criteria and an additional 21 by stenosis criteria. There was one false-negative finding (sensitivity 98 percent). The velocity ratio of the stenosis to the adjacent graft was useful in estimating the degree of stenosis. Color flow duplex imaging reduced examination time through visual feedback by highlighting the graft and areas of high velocity. These results indicate that color flow duplex scanning, combining low- and high-peak systolic criteria, is a very sensitive screening test in the early detection of failing grafts.

Blood Vessel Prosthesis↗
PubMed1988

Iliac artery aneurysms arising in patients having had resections of abdominal aneurysms.

We report the angiographic, computed tomographic, and ultrasonographic findings in two patients with iliac artery aneurysms detected several years after undergoing vascular graft surgery to the aorta. These lesions are often silent until serious complications occur, and they should be treated even when asymptomatic. Radiologists should be familiar with this complication so that it may be more readily diagnosed.

Aged↗
PubMed1982

Exclusion of leukaemic meningitis by quantitation of T and B lymphocytes in cerebrospinal fluid.

Involvement of the central nervous system (CNS) in chronic lymphatic leukaemia (CLL) is rare. However, when a patient with CLL presented with meningeal symptoms and a high CSF lymphocyte count in the absence of identifiable infection, meningeal leukaemia was considered the most likely diagnosis. Subsequent quantitation of T and B lymphocytes in the blood and CSF was found to be a most valuable aid in excluding the diagnosis, and later a cryptococcal infection was proven. This case is reported to draw attention to the value of T and B lymphocyte quantitation where difficulty is experienced in interpretation of cells in CSF in patients with leukaemia or lymphoma.

B-Lymphocytes↗
PubMed1982

Computed tomographic diagnosis of intraventricular hemorrhage. Etiology and prognosis.

Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrhage rather than obstruction of the ventricular system by blood. IVH per se is seldom a major factor in the neurological outcome.

Adolescent↗
PubMed1981

Neonatal intracranial pathology demonstrated by high-frequency linear array ultrasound.

We have performed a total of 126 ultrasound scans of the brain in 86 different neonatal patients with a 7.0 MHz linear array transducer (6.5 cm in length), using the anterior fontanelle as a scanning window. Thirty-one patients had demonstrable abnormalities confirmed by CT while 49 patients were normal. Using this technique we were able to reliably define normal lateral ventricles, subependymal hemorrhages, hematomas, intraventricular hemorrhages, hydrocephalus, and porencephalic cysts.

Brain Diseases↗
PubMed1981

Ultrasonic evaluation of neonatal intracranial hemorrhage and its complications.

High resolution, real-time ultrasound scans were obtained through the anterior fontanelle to examine the intracranial anatomy of 100 neonates. Of 43 patients with abnormalities, 26 had intracranial hemorrhage (subependymal, intraventricular, or cerebral). Of the 51 patients also studied by CT, the sensitivity of ultrasound in detecting hemorrhage was 96% and the specificity 94%. This ultrasound technique was also very useful for detecting complications such as porencephalic and subependymal cysts, ventricular septations, and hydrocephalus. In normal premature neonates (25 to 35 weeks gestation) the lateral ventricles appear as slit-like structures on the coronal scan. The midline-lateral dimension of normal lateral ventricles was 8.6 mm (range 7-11 mm) and the depth of 1.9 mm (range 1-3 mm). Follow-up scans in patients with intraventricular hemorrhage show that in mild hydrocephalus, the lateral ventricle becomes rounded rather than slit-like. This change occurs before the midline-lateral dimension of the ventricle increases.

Brain Diseases↗
PubMed1981

Acute orbital pseudotumors: classification and CT features.

Acute orbital pseudotumors are inflammatory lesions of unknown etiology that may affect part or, less often, all of the tissue within the orbit. A retrospective computed tomographic (CT) study of 16 patients demonstrated that these lesions occur in one of five specific anatomic patterns: anterior, posterior, diffuse, lacrimal, or myositic. The most common location was lacrimal followed by anterior pseudotumors. Posterior, most common location was lacrimal followed by anterior pseudotumors. Posterior, diffuse, and myositic pseudotumors were equally frequent. Localization on the basis of clinical features correlated with the CT localization. Illustrative cases of each of the five types are included. The role of CT in evaluating the therapeutic response is discussed.

Acute Disease↗
PubMed1977

Antibody to hepatitis B surface antigen in laboratory diagnostic sera.

Thirty-four commercial blood-grouping sera were tested for the presence of HBsAg and anti-HBs by radioimmunoassay technic. One sample (2.9% of the total) was positive for HBsAg, a marked reduction from previous reports; however, 11 sera (32.4%) were found to contain anti-HBs, a previously unreported finding. There is still some dispute as to the risk of infection from samples containing anti-HBs, which the authors hope will be resolved when tests for anti-HBc are readily available. In the meantime, the high antibody rate reflects a high rate of exposure to HBsAg of donors of commercial antisera, and laboratory personnel should be reminded of the possible risk of this less obvious source of infection.

Antibodies, Viral↗
PubMed1975

Cold agglutinin formation in patients undergoing haemodialysis. A possible relationship to dialyser re-use.

Cold agglutinins with anti-N characteristics were shown to develop in as short a time as four months in patients on home dialysis. It appeared that the development of such antibodies is related to dialyser re-use. Those who were treated without re-using their dialyser did not develop these antibodies. Anti-N may cause early graft failure associated with agglutination in a cold allograft. Moreover, if these antibodies develop in patients on dialysis there may be problems with extracorporeal dialysis and blood transfusion.

Agglutinins↗