The shortage of qualified technologists and technicians in nuclear medicine is serious problem. The urgent need is not only for additional people, but for more highly qualified ones capable of performing technical functions with minimum of direct supervision, thereby allowing the physician to concentrate more on activities that require his medical skill and judgement. The National Advisory Committee on Radiation in its April 1966 report to the Surgeon General of the Public Health Service stated the problem in the following words: In the field of technological manpower, serious difficulties currently prevail in the provision of adequate numbers of clinical X-ray and Nuclear Laboratory Technologists in the United States. 1 The Committee recommended that the Public Health Service should undertake a series of training programs to provide increasing numbers of technologists in the several disciplines of the Radiological Sciences. As one step toward meeting this challenge, the Public Health
Technetium-99m pertechnetate scintigraphy in three patients with pathologically proven peripheral nerve tumors (six in total) demonstrated its ability to assess accurately the size, location, and the extent of all lesions. Pertechnetate localized only in areas of abnormal nerve involvement and all lesions were better seen in delayed images than the earlier ones. Pertechnetate imaging appears to be a promising method of noninvasive evaluation of clinically evident and occult tumors of peripheral nerve origin.
This clinical study compares the efficacy of two 111In white blood cells preparations. Seventy-six patients were imaged after an injection of granulocytes (GRAN) isolated on a Ficoll-Hypaque gradient and labeled with [111In]acetylacetone (ACAC) in saline; 105 patients were imaged after an injection of GRAN isolated on a metrizamide-plasma gradient and labeled with [111In]tropolone (TROP) in plasma. Early (2-4 hr), intermediate (4-6 hr), and delayed (24 hr) images were obtained. The specificity was quite high (94-100%) in both preparations and no statistical differences could be found. The sensitivity for ACAC-GRAN for the early, intermediate, and delayed images were 39%, 63%, and 64%, respectively; for TROP-GRAN it was 80%, 89%, and 92%, respectively. In all cases the TROP-GRAN images were significantly more sensitive than the ACAC-GRAN images obtained at the same time after injection (p less than 0.001 for early and delayed images, 0.01 less than p less than 0.025 for intermediate images). For ACAC-GRAN the intermediate and delayed images were significantly more sensitive than the early images, while no significant difference could be found for TROP-GRAN. In a blinded experiment, the ability of TROP-GRAN to demonstrate a lesion was compared to that of ACAC-GRAN. TROP-GRAN demonstrated the lesions better than ACAC-GRAN, both in the early and late images (p less than 0.001). TROP-GRAN visualization scores at 4-6 hr equaled those obtained 24 hr after injection. In conclusion, GRAN separated and labeled in plasma with TROP are superior to those separated and labeled in saline with ACAC in three ways: higher visualization scores, earlier visualization of the lesion, and greater sensitivity.
A patient with chronic osteomyelitis had surgery performed between the early and delayed images of an ln-111 granulocyte scan. The early images showed no uptake, while the delayed images demonstrated marked soft tissue uptake, which was felt to be secondary to the inflammation of the intervening surgery. It was concluded that granulocytes, when labeled with ln-111, remain viable and can respond to inflammation that occurs after their injection.
Findings on 262 thoraco-abdominal dynamic studies done at the time of hepatic imaging were reviewed. Twenty-nine extra-hepatic abnormalities were diagnosed solely on the basis of these studies, including pericardial and pleural effusions and decreased perfusion to one lung. Half of these abnormalities were not suspected clinically. The dynamic study is an important part of hepatic imaging and should be performed routinely. Besides aiding in differential diagnosis of various hepatic lesions, extra-hepatic abnormalities can be discovered.
