PubMed Health⌕ Search

Biomedical subjects

K A McKusick

Publications and source records attributed to K A McKusick.

At least 19 recordsLinked to original sources
PubMed1992

Quantitative imaging of Gaucher disease.

Twenty-three patients with type 1 Gaucher disease were evaluated with a battery of quantitative imaging techniques. Plain radiographs were used to measure cortical thickness and Erlenmeyer flask deformity. Xenon-133 uptake was measured in scans of the lower extremities. Dual-energy quantitative computed tomography was used for calculation of trabecular bone and bone marrow fat content in the spine and long bones. Magnetic resonance (MR) imaging was performed to evaluate disease extent and three-dimensional splenic volume. MR images were also used to provide quantitative measurements of each vertebral fat fraction. Each imaging modality was correlated with the others as well as with the clinical history of skeletal complications and the hematocrit and acid phosphatase activity. There was a strong relationship between splenic volume and disease severity as measured clinically and with laboratory testing. The spinal fat fraction also correlated with these measures of disease severity and with the femoral fat fraction and xenon uptake. No measurement allowed discrimination of patients with from those without skeletal complications.

Adolescent↗
PubMed1979

Left superior vena cava to left atrial communication diagnosed with radionuclide angiocardiography and with differential right to left shunting.

Anomalous left superior vena cava to left atrial communication, although rare, should be considered in the presence of a right to left shunt without right ventricular hypertrophy, especially when the cause of the shunt cannot be identified at cardiac catheterization. We present a case with a diagnosis based on two radionuclide techniques. Nuclear angiography, performed after the injection of technetium-99m pertechnetate into the left arm, demonstrated the anomaly. Total body scans performed after intravenous injections of labeled albumin microspheres indicated 65% right to left shunting of left arm venous return but only 9% shunting of right arm venous return, findings that are diagnostic of left superior vena cava to left atrial communication.

Angiocardiography↗
PubMed1979

Of linens and laces--the eighth anniversary of the gated blood pool scan.

Evaluation of ventricular performance is essential in the diagnosis and long-term management of patients with heart disease. This can be most easily performed clinically using simple tools. When more definitive objective assessment of cardiac function is indicated, the equilibrium gated blood pool study provides reliable angiographic evaluation of the heart. It will continue as a mainstay in the armamentarium of cardiology.

Cardiac Output↗
PubMed1979

Evaluation of gastrointestinal bleeding by red blood cells labeled in vivo with technetium-99m.

To determine the effectiveness of abdominal imaging with RBCs labeled in vivo with Tc-99m, for the detection of gastrointestinal (GI) bleeding, 28 control subjects and ten patients with suspected bleeding underwent scintigraphy at 0-24 hr after tracer injection. Colonic activity was noted in one of the controls within 3 hr of injection, and in five of ten controls at 24 hr, all of whom had initial gastric activity. Of the ten patients with suspected GI bleeding, eight had documented active bleeding; seven of these had positive scintigrams. Nasogastric (NG) suction markedly decreased the presence of initial gastric activity in the patients with active bleeding. With this blood-pool radiopharmaceutical, frequent imaging of the abdomen over 24 hr can be done to test active bleeding. Continuous NG suction is recommended to reduce accumulation of gastric activity. These results suggest that red blood cells labeled in vivo with Tc-99m provide a sensitive method of detecting active GI bleeding.

Adult↗
PubMed1979

The significance of augmented radiocolloid uptake by the spleen in patients with malignant melanoma.

Increase in splenic uptake of Tc-99m sulfur colloid was noted in 47 of 147 (32%) patients with cutaneous malignant melanoma early in the coure of disease. Patients with disseminated disease and/or clinical or laboratory evidence of hapatic dysfunction were excluded from study. Recurrence rate of 2 yr was higher for those patients with splenic scans demonstrating augmented uptake compared with patients having normal scans, 36% against 16% (p less than 0.02). These differences resulted from a much more favorable prognosis in women with normal scans contrasted with women with increased uptake, 6% against 26% (p less than 0.05). Women with increased splenic uptake, and all men regardless of scan status, seemed to have a higher rate of recurrence than women with normal spleen scans. Scan status may be an adjunctive prognostic marker in women.

Colloids↗
PubMed1979

Noninvasive estimation of pulmonary arterial pressure by analysis of pulmonary blood-flow distribution.

To determine whether a correlation exists between pulmonary arterial (PA) pressure (Pa) and the distribution of pulmonary blood flow, this distribution was measured in four upright dogs in the control state and during intravenous infusions of epinephrine or prostaglandin F2 alpha. During suspension of respiration, 15 mCi of Xe-133 were injected intravenously, and perfusion and equilibration lung images were recorded with a scintillation camera. The procedure was performed several times on each dog, with and without pharmacological elevation of PA pressure by 5 to 50 cm H2O. For each scintigram, the relative blood flow per unit ventilated lung volume (F) was plotted against centimeters above the hilum (h). Pulmonary arterial pressure was derived from each curve, assuming the relation F = B(Pa - hD)2, where B = constant and D = specific gravity of blood. Calculated PA pressure correlated strongly (r = 0.83) with measured PA pressure, suggesting a possible means of noninvasive estimation of PA pressure.

Animals↗
PubMed1978

Scintigraphic detection of pulmonary emboli by serial positron imaging of inhaled 15O-labeled carbon dioxide.

Inhaled radioactive carbon dioxide is retained in pulmonary blood distal to embolic obstruction and appears as an area of increased radioactivity that delineates the site and magnitude of the affected zone. The scintigraphic detection of pulmonary emboli by serial imaging of inhaled carbon dioxide labeled with cyclotron-produced 15O2 was evaluated in 27 patients undergoing conventional pulmonary ventilation/perfusion imaging and pulmonary arteriography. Fifteen patients proved to have pulmonary emboli on arteriography. Sensitivity (87%) and specificity (92%) rates for inhalation imaging were superior to those of conventional ventilation/perfusion imaging (P less than 0.05). Clearance of 15O2 activity was markedly delayed over embolized pulmonary segments (mean half time of 47.0 +/- 11.1 seconds [S.E.M.]) in comparison to normal segments (mean of 3.6 +/- 0.08 seconds; P less than 0.001). Pulmonary imaging by this method provides an approach to the detection of pulmonary emboli that is relatively sensitive and specific and permits analysis of persisting perfusion in embolized pulmonary segments. A major practical limitation, however, is the necessity of a nearby cyclotron.

Adult↗
PubMed1978

The clinical course of patients with suspected pulmonary embolism and a negative pulmonary arteriogram.

Selective pulmonary arteriography, with superselective magnification views of the lung bases or other areas where abnormalities are shown on perfusion lung scans, performed within 24-48 hours after the onset of symptoms, can effectively rule out clinically significant pulmonary thromboembolism. One hundred and eighty consecutive patients (minimum follow up, six months) with suspected pulmonary embolism and negative pulmonary arteriograms were studied. Not one of the 167 untreated patients died as a result of thromboembolic disease during the acute illness (20 died from unrelated causes), and none of the 147 patients who survived suffered "recurrent embolism" during follow up.

Adolescent↗
PubMed1978

Early diagnosis of disc-space infection using Gallium-67.

A 4-year-old boy had had progressive central lumbar pain and hamstring spasm. He had a normal lumbar-spine x-ray except for minimal L-5, S1 spondylolysis, but gave an abnormal gallium-67 scan in the region of the low lumbar spine. Eight weeks following intensive antibiotic therapy, confirmation of the diagnosis of disc-space infection was established by roentgenographic studies that demonstrated narrowing of the L 4-5 intervertebral disc space. A technetium-99m diphosphonate bone scan, performed concurrently with the gallium-67 study, was normal.

Bacterial Infections↗
PubMed1977

Hepatoadenoma and focal nodular hyperplasia: pitfalls in radiocolloid imaging.

Both hepatoadenoma and focal nodular hyperplasia must be considered in the differential diagnosis of right upper quadrant pain or mass in young women taking oral contraceptives. Three new cases are presented, and the radionuclide scan findings of 35 additional cases reviewed. There is great variability in the radiocolloid liver scans of these entities. Hepatoadenomas often develop along the inferior margin of the liver, and may therefore go undetected by radiocolloid imaging.

Adenoma↗
PubMed1977

Detection of left atrial myxoma by gated radionuclide cardiac imaging.

Gated radionuclide cardiac blood pool scans (GCS) of end-systole and end-diastole or eight images subtending the entire cardiac cycle were performed on seven patients with left atrial myxomas documented by pulmonary cineangiography with left atrial follow-through. The ethocardiogram was either suggestive or diagnostic in all patients. In addition to demonstration of the tumor (6 patients), the GCS detected three patterns of tumor motion: 1) a defect which moved from the left atrium in end systole to the left ventricle in end diastole (2 patients); 2) a defect which remained within the region of the left atrium but decreased in size between end diastole and end systole (3); and 3) a defect which was observed within the region of the left ventricle in end diastole but disappeared in end systole (1). Thus, the GCS is a noninvasive method for detection and evaluation of motion of left atrial myxomas.

Adult↗
PubMed1977

Differentiation of transiently ischemic from infarcted myocardium by serial imaging after a single dose of thallium-201.

Myocardial 201Tl uptake and regional blood flow by the microsphere technique were determined in anesthetized dogs undergoing either 20 min of coronary occlusion and 100 min of reperfusion (N = 10) or 120 min of occlusion (N = 4). In both groups, 201Tl was injected intravenously after 10 min of occlusion. In transiently occluded dogs, regional flow at the time of 201Tl administration was reduced to 8 +/- 3% of normal flow in endocardial layers of the central ischemic zone. After 100 min of reperfusion, flow values were not significantly different from normal. 201Tl activity after reperfusion rose to 56 +/- 5% of normal, demonstrating that redistribution of the radionuclide occurred during the reflow period. In animals with persistent occlusion, there was a significant relationship between 201Tl uptake and flow (r = 0.95) and no evidence of redistribution of 201Tl during the two hour occlusion period. In another five dogs receiving 201Tl, serial gamma camera images obtained during reperfusion showed increasing uptake of the tracer in apical defects which returned to normal by 4 hours of reflow. Thirteen patients with stable angina received 2 mCi of 201Tl intravenously at peak exercise, and multiple gamma camera images obtained serially. All demonstrated zones of diminished 201Tl uptake 10 min after exercise. Defects which partially or completely disappeared within 1-6 hours postexercise corresponded to areas supplied by coronary arteries with significant stenoses. Persistent defects were present in regions of old myocardial infarction. Six additional patients with acute myocardial infarction demonstrated 201Tl myocardial defects which showed no significant change over 6 hours. Thus, redistribution of 201Tl into ischemic myocardium was demonstrated during transient coronary occlusion in dogs and after exercise stress in man. Sequential imaging after a single dose of 201Tl at the time of exercise may provide a means for distinguishing between transient perfusion abnormalities or ischemia and myocardial infarction of scar.

Acute Disease↗
PubMed1977

Differentiation between renal allograft rejection and acute tubular necrosis by renal scan.

The usefulness of the renal scan in diagnosing technical complications in the transplant patient is well established. However, the ability of the renal scan to differentiate between acute rejection and acute tubular necrosis has remained uncertain. We have evaluated the effectiveness of the 99mTc DTPA computer-derived time-activity curve of renal cortical perfusion, as well as data obtained from scintillation camera images, in making such diagnoses. Fifteen patients with a clinical diagnosis of either acute rejection or acute tubular necrosis, or both, were studied retrospectively. Technetium scan diagnoses did not agree with the clinical assessment in nine of the patients. Thus selection of a course of treatment should not be based on data obtained from the scan alone.

Acute Kidney Injury↗