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Biomedical subjects

V A Brookeman

Publications and source records attributed to V A Brookeman.

At least 19 recordsLinked to original sources
PubMed1990

Estimation of 24-hour thyroid uptake of I-131 sodium iodide using a 5-minute uptake of technetium-99m pertechnetate.

The authors have developed a method to estimate the 24-hour sodium iodide thyroid uptake based on a 5-minute Tc-99m pertechnetate thyroid uptake using the equation: Estimated Iodide Uptake = 17.72*In(Pertechnetate Uptake) + 30.40. This estimation has a correlation coefficient of 0.90. It is based on a data pool of 44 patients who underwent I-131 and Tc-99m studies within 2 weeks of each other from 1978-1988, with established diagnoses as follows: 12 euthyroid, 6 hyperthyroid with multinodular goiters, 15 hyperthyroid with diffuse goiters, 4 with subacute thyroiditis, and 7 unknown. The population consisted of 30 women and 14 men with a mean age of 52.0 +/- 17.5 years; this sample was screened for use of thyroid hormone, propylthiouracil, and radiographic contrast. The authors believe this estimation method is of value whenever a 24-hour iodide uptake is desired, and where speed and minimizing radiation dose are factors. This method is strongly recommended for thyroid uptake evaluation before I-131 therapy.

Adolescent↗
PubMed1988

Choledochal cyst: diagnosis in neonates.

We have described the radionuclide scintigraphic and sonographic findings in two cases of neonatal choledochal cyst. These studies can be used in complementary fashion in evaluating this uncommon cause of neonatal jaundice.

Common Bile Duct Diseases↗
PubMed1987

Patent umbilical vein. Diagnosis by technetium-99m tagged red blood cell scintigraphy.

Abdominal scanning with Tc-99m labeled red blood cells serendipitously demonstrated collateral flow in a patent umbilical vein in a patient with unsuspected advanced cirrhotic liver disease and portal hypertension. Knowledge of this was crucial in planning the optimal surgical approach in this patient, referred for resection of a bladder carcinoma. Furthermore, the nuclide study was helpful in clarifying several questions posed by a prior abdominal pelvic CT scan.

Collateral Circulation↗
PubMed1978

Computers and quality control in nuclear medicine.

The general topic of computers and nuclear medicine quality control may be approached from two main areas; controlling the quality of computerized studies, and computer applications in general nuclear medicine quality control. Overlap occurs when quality control of computer studies is performed by the computer itself. The uses of computers in record-keeping and in quality control of imaging instrumentation and in vitro studies, including radioimmunoassay, are discussed in this review. Aspects of quality control for computerized clinical cardiovascular, cerebral, and renal studies and emission computed tomography are reviewed, including consideration of difficulties and inaccuracies involved in the studies. Any automatic computer analysis program should incorporate adequate checks and error detection protocols and should illustrate results for verification. Current routine quality control procedures using the computer unfortunately are few. Quality control criteria are needed for camera/computer systems in high count rate clinical applications, and increasing emphasis should be aimed at quality control of those computerized dynamic and function studies in current clinical use. The computer has a valuable potential for nuclear medicine quality control. In vitro and computerized in vivo studies can be analyzed by readily available statistical programs, and variances can be monitored continuously. Computers can calibrate and monitor instrument performance regularly, and can handle managerial and clerical duties such as bookkeeping.

Cardiovascular Diseases↗
PubMed1978

Electron dose reduction coefficients for seven radionuclides and cylindrical geometry.

In determining internal radiation absorbed dose it is frequently not possible to assume a uniform distribution of radionuclide in an infinite, homogeneous, absorbing material. When the source-target geometry is such that the target is source-free, special considerations must be given to the dose contributions from electrons, since the conventional assumption of 100% absorption of non-penetrating radiations leads to overestimation of the absorbed dose. The absorbed dose from electrons determined at a point within the source-free region depends upon the depth within it. Electron dose reduction coefficients determined at appropriate distances from the source surface are multiplied by the electron doses determined from the general absorbed dose equation. This method of correcting for source-free regions has been applied to cylindrical and planar geometry, for spinal cord and nerve root dosimetry in cisternography. Utilising published scaled point kernels for mono-energetic electrons, electron dose reduction coefficients have been determined as a function of depth from the source surface for cylindrical source-free regions of radii 0.5, 0.05 cm and infinity, and seven gamma-ray-emitting radionuclides: 51Cr, 67Ga, 99Tcm, 111In, 113Inm, 169Yb and 203Pb. These values may be used in other internal radiation absorbed dose situations, and similar techniques applied to other source-target geometries.

Humans↗
PubMed1975

Dosimetry of several DTPA radiopharmaceuticals in cisternography.

Previously published biologic distribution and clearance data for 169Yb-DTPA in cisternography were utilized to obtain effective spinal segment clearance data for six other easily dhelated radionuclides: 99mTc, 113mIn, 111In, 67Ga, 51Cr, and 203Pb. Absorbed radiation doses to the spinal cord and nerve roots were calculated for each radioactive DTPA compound, employing appropriate cylindrical geometry and reduction coeffients for the dose contributions from the electrons of each radionuclide. Doses are maximal at the surface and decrease rapidly with distance from the surface. The relative useful photon flux from each DTPA radiopharmaceutical for approximately the same average absorbed radiation dose to the spinal cord was determined. The results indicate that 111In and 203Pb should be considered as possible radionuclide tags for DTPA cisternographic imaging.

Brain Neoplasms↗