Jack K. Goodrich

Quantitative radionuclide angiocardiography for determination of chamber to chamber cardiac transit times

Abstract A radionuclide method is described for determination of chamber to chamber cardiac transit times using only an intravenous injection. Using the Digital Autofluoroscope, counts of radioactivity from each square centimeter over the precordium were recorded onto computer tape at 0.23 second intervals after intravenous injection of 10 millicuries of 99mtechnetium pertechnetate. Computer analysis of counts grouped detector units with similar time responses into areas corresponding to discrete cardiac regions. From the resulting indicatordilution curves, appearance, peak and mean transit times were calculated for each cardiac region. Studies were obtained in 10 normal subjects, 14 patients with cardiac septal defects and left to right shunting and 20 patients with valvular stenosis or insufficiency. Among the latter patients, 8 had mitral stenosis and 8 had aortic insufficiency. Patients with a left to right shunt greater than 15 percent consistently demonstrated rapid pulmonary transit of tracer. In addition, specific abnormalities of curve configuration occurred in patients with a shunt greater than 30 percent. Transit times from the right atrium to left ventricle averaged 9.2 ± 1.2 seconds in normal subjects, 13.3 ± 2.2 seconds in patients with mitral stenosis and 14.6 ± 2.8 seconds in patients with aortic insufficiency. Pulmonary mean transit time was 6.6 ± 1.1 seconds in normal patients, 9.2 ± 1.7 seconds in those with mitral stenosis and 11.7 ± 3.1 seconds in those with aortic insufficiency. Pulmonary blood volume was 362 cc/m2 in patients with mitral stenosis and 508 cc/m2 in those with aortic insufficiency. These data suggest that pulmonary mean transit time was prolonged primarily by decreased cardiac output in mitral stenosis and by increased pulmonary blood volume in aortic insufficiency. The simple technique described consistently provided hemodynamic data that appear to be useful for diagnosis and management of cardiac diseases.

Scintiangiocardiography in children: Rapid sequence visualization of the heart and great vessels after intravenous injection of radionuclide

Abstract A technique is presented for recording rapid sequential scintillation camera images of the heart and great vessels in children after the intravenous injection of radionuclide. The wide-field Anger scintillation camera, a memory oscilloscope and a 35 mm motor-driven camera are used to record images directly from the oscilloscope during the initial circulation of the radionuclide. Patients are studied in the supine position and intravenously administered technetium-99m as the pertechnetate ion in a dose of 140 μc/kg (maximal dose, 7.5 mc) is used. For each study 24 to 36 photographs are recorded with exposures of 0.25 or 0.125 sec and 1.8 or 3 exposures per sec. With this technique the central circulation is depicted by a trail of scintillations in a manner similar to that of conventional cineangiocardiography. First the normal sequential scintillation images of the heart and great vessels were clarified by studying patients without heart disease undergoing diagnostic brain scans. Then children known to have heart disease and previous cineangiocardiography were studied to compare this method with conventional contrast media visualization of the central circulation. Systemic venous abnormalities as well as alterations in intracardiac and great vessel anatomy were demonstrated with this technique. In addition, right to left shunts can be shown by early appearance of activity in the abdominal aorta. This technique is not hazardous, is associated with low radiation exposure, does not disturb circulatory hemodynamics and provides a useful diagnostic tool in the treatment of children with heart disease.

Brain Scans of Cerebral Infarcts with Radioactive Mercury

The reported incidence of positive scans in the presence of cerebral infarction varies between 25 and 81 per cent (1–8). In a previous report (9) of 129 cases, the present authors found 41 per cent positive, with the greatest number of positive scans in the third week postinfarction. The purposes of the present study are several: (a) to better elucidate the type of cerebrovascular lesion which will produce an abnormal brain scan, (b) to more clearly define the post-infarct periods when the scans are negative and positive, (c) to correlate infarct size as judged clinically with the brain scan results, (d) to demonstrate infarcts by scan in the anterior, middle, and posterior cerebral and the basilar-vertebral artery distributions, and (e) to evaluate the brain scan for its value in diagnosis and prognosis. Materials and Method This study analyses 179 brain scans in 152 patients with the diagnosis of cerebral infarction. Scans were performed three to five hours after intravenous injection of Hg203- or Hg197...

Inhalation and Perfusion Radionuclide Studies of Pediatric Chest Disease

DELINEATION of the physiological changes in chronic pediatric pulmonary diseases continues to evade pediatricians and pulmonary physiologists, largely because present study methods are inadequate for the task. The obstacles to accurate clinical evaluation of children with pulmonary pathology are great. Personnel must be specially trained to perform the studies. Equipment must have low resistance and minimal dead space because of the smaller bronchial diameters and lung volumes involved. The child must be able to cooperate, a factor which depends upon his age, learning ability, fears, and physical strength. Finally, the results cannot be assessed on a single standard, but must be interpreted according to each childs age and size. Even when all contributing factors combine to create ideal conditions, areas of uneven ventilation are difficult to assess (10). Recent advances in nuclear medicine have yielded new and possibly better approaches to this problem. We have used a technic of inhalation lung-scanning...

Xenon-133 Measurement of Regional Ventilation

A clinically applicable method for quantitating regional ventilation and expressing both pulmonary ventilation and perfusion by 3-dimensional images is described. Studies on dogs intubated with Carlens tubes established the relationship between the slope of 133Xe disappearance from the lungs with regional ventilation. Three clinical cases illustrate a means of assessing pulmonary arteriovenous shunting, the value of quantitative pulmonary function measurements in chronic inflammatory lung disease and chronic pulmonary embolization. The data obtained required detector variability and dead-timeloss corrections by the 360/75 computer to be considered valid.

An experimental partial occlusive device for vessels delivered by arterial catheter

Abstract A technique has been described in which experimental stenosis of vessels has been obtained in laboratory animals. A remote catheter technique has been utilized. The advantages of this approach over a direct surgical approach for creating vascular stenotic lesions are listed.

Relative decreased splenic uptake of Tc-99m-sulfur colloid in patients with pancreatic carcinoma

Relative spleen/liver activity ratio was determined from posterior projection images using a photodensitometric method. Ratios from scans of 22 patients with proven pancreatic carcinoma (12 from rectilinear scans and 10 from scintillation camera images) were determined and compared to studies from patients documented as normal and to randomly selected liver/spleen imaging studies which had been previously interpreted as normal. The mean ratio from the pancreatic carcinoma group was significantly lower than the means of the respective normal groups (p[t] < .0001 for rectilinear scans and p[t] < .001 for scintigrams). There was no significant difference between the means of the proven normal and randomly selected normal groups or between the two pancreatic carcinoma groups. Splenic vascular alteration is discussed as a possible reason for decreased splenic distribution of Tc-99m-sulfur colloid in this patient group.

Radioiodination of biologically active compounds: a simplified solid-state enzymatic procedure

A simplified solid-state enzymatic iodination procedure for routine labeling of unstable pure protein or complex amino acid-containing molecules is presented. The procedure was designed using agarose-bound lactoperoxidase to iodinate human IgG with iodine-125. This method consistently resulted in a labeling efficiency greater than 90% with high stability and undetectable gross structural alterations of the substrate as evaluated by immunodiffusion and electrophoresis. The technique presented is simple, efficient, and may be employed to yield a sterile, pyrogen-free labeled species.

Characterization of Malignant Gliomas and Cerebrovascular Disease by Cerebral Dynamic Studies

A technique for analysis of dynamic radionuclide studies of the cerebral circulation is described. This technique permits objective classification of observed radionuclide distribution patterns. Variation in the time-to-peak activity, and in the maximum attained activity as determined by region-of-interest analysis of cerebral hemispheric activity, was defined for a normal population. Application of these normal values permits classification of observed hemispheric radionuclide distribution patterns in anaplastic gliomas and in occlusive cerebrovascular disease. Radionuclide activity in gliomas may be normal, decreased, or increased in the region of the tumor. In cerebrovascular occlusion, decreased activity, associated with a delay in time-to-peak activity, is frequently demonstrated in the affected hemisphere.