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Biomedical subjects

D R Biello

Publications and source records attributed to D R Biello.

31 records · Page 2Linked to original sources
PubMed1981

Scintigraphic detection of pulmonary embolism in patients with obstructive pulmonary disease.

The 133Xe ventilation (V) studies, 99mTc perfusion (P) lung images, and pulmonary angiograms of 83 patients with obstructive pulmonary disease (OPD) and suspected pulmonary emboli (PE) were reviewed. Each patient had ventilation abnormalities suggesting OPD and at least one region showing matched V-P abnormalities. All angiograms were obtained within 72 hours of the V-P study and were reviewed independently. The overall sensitivity of V-P imaging for PE in this population was 0.83 and its specificity was 0.92. False-negative interpretations occurred in three of the 16 patients who showed ventilation abnormalities in more than 50% of their lung fields. In the 67 patients with ventilation abnormalities in less than or equal to 50% of their lung fields the sensitivity (0.95) and specificity (0.94) for detecting PE were high, V-P imaging is a reliable method for detecting PE in patients with regions of V-P match, if the ventilation abnormalities are limited in extent.

Adult↗
PubMed1981

A new scintigraphic technique for assessment of right atrial function.

Gated radionuclide imaging with 99mTc-labeled red blood cells was employed to assess changes in right atrial (RA) volume in 17 subjects. Studies were repeated within two hours in five of 12 normal subjects and at two and ten days after infarction in five patients. Time-activity curves were generated for the RA and right ventricle (RV) from variable regions of interest defined by automatic edge detection. The RA time-activity curve exhibited four phases: filling, early emptying, equilibration, and late emptying. Repeated measurements of RA early emptying rates correlated closely in normals (r = 0.93). Early RA emptying and RV filling rates corresponded closely (r = 0.89). In four patients with infarction, the RA emptying rate was slowed on the first study but had normalized by 10 days. In a patient with inferior infarction and suspected RV infarction, the RA emptying rate was depressed and remained so for 10 days. Thus, relative changes in right atrial volume can be assessed reproducibly by a radionuclide technique, which is relatively independent of geometric assumptions. This technique offers great promise as a method to assess atrial function in health and disease.

Adult↗
PubMed1981

Evaluation of computer display systems using digital test patterns.

Two digital test patterns are used to evaluate computer video display systems. One pattern consists of linear and logarithmic gray-scale wedges, blocks of constant brightness, and horizontal and vertical bar patterns. The other is a cross-hatch bar pattern. These patterns are used to assess display systems' gray scale, resolution, and spatial linearity. Microdensitometry measurements were performed to determine brightness uniformity, spatial resolution, and to relate optical density to exposure. These test patterns, used qualitatively, are useful in the routine adjustment and quality control of digital systems. The precise quantitative characterization of a display system is important in research applications involving image processing.

Computers↗
PubMed1980

Comparison of 133Xe single-breath and washout imaging in the scintigraphic diagnosis of pulmonary embolism.

To compare the utility of 133Xe single-breath (SB) and prolonged washout (WO) imaging in the scintigraphic diagnosis of pulmonary embolism, ventilation and perfusion studies of 66 patients who had pulmonary angiography within 48 hours were reviewed. The single-breath-perfusion (SB-P) and washout-perfusion (WO-P) studies agreed in 59 of 66 patients (89%). Each of the seven patients with disparate interpretations had an SB-P interpretation with a high probability for pulmonary embolism and a WO-p reading of low probability, with 133Xe retention in areas which appeared normal on the SB image. Single-breath images with 133Xe are not suitable as the sole determinant of ventilation-perfusion (V-P) match or mismatch, especially when subsegmental perfusion defects are present. Prolonged washout imaging improves the specificity of V-P imaging in patients with suspected pulmonary embolism.

Adult↗
PubMed1979

The roles of Gallium-67 scintigraphy, ultrasonography, and computed tomography in the detection of abdominal abscesses.

The evaluation of patients with suspected abdominal abscesses begins with a history and careful physical examination. Gallium-67 (67Ga) scintigraphy, ultrasonography (US), and computed tomography (CT) are utilized only after other routine investigations have failed to localize the abscess. All three modalities are reliable for the detection of abdominal abscesses. The decision regarding which of these three diagnostic tests to use in a particular patient rests upon clinical considerations. If the patient has acute localizing signs and symptoms, 67Ga should not be used initially. In this type of patient, rapid diagnosis is best provided by either US or CT. Further radiologic investigation may be terminated if the CT or US findings are characteristic of an abscess. A 67Ga scan should be performed in a patient with acute localizing signs and symptoms if the initial CT or US is negative. In a patient with nonlocalizing signs and symptoms, 67Ga imaging should be employed as the first procedure since the entire body is easily surveyed. If the 67Ga images are abnormal, then CT or US should be utilized for further lesion characterization. This diagnostic approach will optimize the rapidity of patient evaluation and will minimize diagnostic errors.

Abdomen↗
PubMed1979

Interpretation of indeterminate lung scintigrams.

Lung scintigrams and pulmonary angiograms of 111 patients with suspected pulmonary embolism who had matching perfusion defects and radiographic abnormalities (infiltrate, atelectasis, or effusion) were reviewed. In 14 patients perfusion defects were substantially smaller than the corresponding radiographic opacity; only 1 (7%) had pulmonary embolism. In 77 the opacities and perfusion defects were of similar size; the abnormality was due to embolism in 20 (26%). In 18 patients perfusion defects were substantially larger than the radiographic opacities and were not associated with matching ventilation abnormalities; of these, 16 (89%) had pulmonary embolism. Evaluation of the relative size of perfusion defects and radiographic abnormalities occurring in the same region improves the ability of lung scintigrams to predict pulmonary emboli.

Adult↗
PubMed1979

Computed tomography and 67Ga citrate radionuclide imaging for evaluating suspected abdominal abscess.

A retrospective analysis of the results of 67Ga citrate radionuclide imaging and computed tomography (CT) in 45 patients with suspected abdominal abscess was conducted to determine the mertis of each method. Both techniques were highly sensitive in detecting abdominal abscesses, and often provided complementary and supplementary diagnostic information; their combined use many times offset the limitations of each method used alone. Guidelines are suggested that permit rapid evaluation, while limiting diagnostic errors, when using 67Ga citrate radionuclide imaging and CT in the presence or absence of localizing symptoms and signs.

Abdomen↗
PubMed1979

Ventilation-perfusion studies in suspected pulmonary embolism.

The results of ventilation-perfusion (V-Q) imaging and pulmonary angiography were retrospectively analyzed in 146 patients with suspected pulmonary embolism (PE) to define the frequency of PE associated with various scintigraphic patterns. When the radionuclide images demonstrated at least two moderate-sized or one large area of V-Q mismatch, the probability of PE was 92%. However, only one of three patients with a single moderate-sized V-Q mismatch had PE, while small V-Q mismatches were not associated with PE in any of 19 patients. Matched V-Q abnormalities in lung regions that were radiographically normal were infrequently due to PE (4.8%). When a perfusion defect was substantially smaller than a corresponding radiographic abnormality, the frequency of PE was low (7.7%). Conversely, when a perfusion defect was substantially larger than the corresponding radiographic abnormality, there was a high probability of PE (87%). Matched perfusion and radiographic abnormalities indicated an intermediate probability of PE (27%). Patients with suspected pulmonary embolism may be classified into groups with low, intermediate, or high probability of pulmonary embolism on the basis of size and number of perfusion defects and a careful comparison of perfusion defects with ventilatory and radiographic findings.

Angiography↗
PubMed1978

Computed tomography and radionuclide imaging of the liver: a comparative evaluation.

The authors retrospectively analyzed the results of radionuclide imaging (RI) and computed tomography (CT) of the liver in 174 patients. RI correctly identified 90% of patients with focal hepatic lesions while CT identified 85%. CT was capable of differentiating tumor, abscess/hematoma, and cyst while RI was more sensitive in the detection of hepatocellular disease. CT distinguished regenerating nodules from other focal lesions. Radionuclide imaging remains the preferred initial screening examination in patients with suspected focal liver disease, while CT is the examination of choice to distinguish obstructive from nonobstructive jaundice.

Diagnostic Errors↗
PubMed1976

Correlation of renal images on bone scan and intravenous pyelogram.

The reliability of renal images using the 99mTc-labeled bone-seeking radiopharmaceuticals was evaluated by comparing abnormal renal images on bone scan with IVP and, conversely, abnormal findings on IVP with renal images on bone scan. Several findings on the bone scan renal images were associated with abnormalities on IVP. However, some conditions may not be detected on the bone scan images which are demonstrated on IVP. Results suggest that an abnormality of the renal image on bone scan warrants further investigation while a normal renal image does not exclude renal pathology.

Bone and Bones↗