Recombinant human thyroid-stimulating hormone-aided scintigraphy: comparison of imaging at multiple times after I-131 administration.

PURPOSE: Recombinant human thyroid-stimulating hormone (rhTSH) may be used in lieu of thyroid hormone withdrawal for the evaluation of thyroid cancer. Scintigraphy using the existing rhTSH protocol is performed 48 hours after I-131 administration. The authors investigated the feasibility of whole-body imaging at 72 hours and evaluated thyroid tissue uptake at 48 to 144 hours. METHODS: Thirty-two patients who previously had thyroidectomy for thyroid cancer were examined. Whole-body imaging was performed routinely at 48 and 72 hours after I-131 administration. Thyroid tissue was visualized in 12 patients, and large foci were imaged for as long as 144 hours. Activity ratios for thyroid tissue to background were determined for 10 patients. RESULTS: Whole-body images at 48 and 72 hours were comparable, generally with lower background activity at 72 hours, and thyroid tissue was well visualized at all times after 48 hours. Thyroid tissue-to-background activity ratios at 72 to 144 hours were equal to or greater than those at 48 hours in 9 of 10 patients. CONCLUSIONS: Recombinant human TSH-aided whole-body scintigraphy is possible 72 hours after I-131 administration, adding flexibility and convenience to the existing protocol and permitting confirmation of findings at 48 hours. Tracer uptake in thyroid tissue persists at later times. Therefore, rapid clearance of background activity appears to be the primary cause of the previously reported decrease in radioiodine retention in euthyroid persons receiving rhTSH.

Penile scintigraphy for priapism in sickle cell disease.

UNLABELLED: Penile scintigraphy with [99mTc]pertechnetate/99mTc-RBCs was performed in patients with sickle cell disease patients who had priapism to assess the role of this imaging procedure in directing the clinical management of these patients. METHODS: Fifteen studies were performed in 13 patients who were treated according to a protocol not dependent on the imaging results. The scintigraphic findings of penile vascular perfusion (stagnant or nonstagnant patterns) were collated retrospectively with the form of treatment needed for relief of the condition. RESULTS: Four of five patients with the nonstagnant perfusion pattern responded to analgesics and intravenous hydration. Four of eight patients with the stagnant pattern did not require any aggressive interventions such as corporeal aspiration/irrigation, intracorporeal epinephrine or glans-cavernosa shunt. CONCLUSION: Whereas the nonstagnant scintigraphic finding appeared to be a favorable indicator for conservative treatment, the stagnant finding was apparently noncontributory. In addition, no correlation was found between these two types of scintigraphic patterns and the subsequent sexual potency of these patients.

Pitfalls and limitations of diuretic renography.

We report five pediatric cases that illustrate the methodologic pitfalls and limitations of diuretic renography in suspected ureteropelvic junction obstruction. False-positive studies may be related to such avoidable flaws in methodology as premature diuretic administration, inadequate diuretic dose, and bladder distension, or to recent pyeloplasty. False-negative results may occur despite optimum technique, necessitating a follow-up study for confirmation.

Diuretic renography: concepts and controversies.

Diuretic renography has proved to be a reliable, noninvasive test for the diagnosis of upper urinary tract obstruction. False positive and false negative results may occur but can be minimized by careful attention to technique. The timing of diuretic administration, state of hydration, and furosemide dosage appear to be the key methodologic variables.

Testicular scintigraphic findings two to three months after torsion. Correlation with sonography and histopathology.

A patient with a nontender testicular mass had sonographic abnormalities compatible with but not entirely typical of a chronic torsion. His scintigraphic studies, done on the same day as ultrasonography and 1 month later, revealed only findings consistent with a very mild subsiding scrotal inflammatory process. On surgical exploration and pathologic examination, it was found that he had an organizing infarct of the testicle secondary to torsion. The clinical history, diagnostic studies, and microscopic slides of the surgical specimen were reviewed. It appeared that tissue granulation and lipogranulomatous changes in the epididymis, known histologic sequelae to the unusually prolonged testicular torsion of 2-3 months, produced scintigraphic findings different from those which have been described for a late or an atrophic torsion.

Optimizing radiologic costs in the DRG environment.

Previously developed consensus algorithms expressing a suggested radiologic workup for the diagnostic related groups (DRGs) specified by the prospective reimbursement policy have proven to be useful tools for investigating radiologic decision making and the resulting economic implications. The mathematical equations for determining diagnostic and therapeutic costs for two alternative algorithms for suspected acute cholecystitis are formulated. Illustrative examples and graphic displays are given regarding how such algorithms and equations are useful in finding answers to questions about the appropriate diagnostic workup, time, and cost. Exploration of the effect of different parameter values on the choice of the appropriate algorithm is illustrated.

Hepatic uptake of technetium-99m diisopropyl iminodiacetic acid (DISIDA) is not impaired by very high serum bilirubin levels.

The hepatic clearance of Tc-99m labeled iminodiacetic acid (IDA) compounds is believed to be impaired in patients with severe hyperbilirubinemia. Competitive inhibition of hepatocyte uptake of IDA by bilirubin has been demonstrated in vitro, but not by clinical scintigraphy. We present a patient with Crigler-Najjar syndrome without evidence of hepatobiliary damage, who demonstrated normal uptake and excretion of Tc-99m DISIDA despite a serum indirect bilirubin level in excess of 30 mg/dl. It is therefore suggested that a markedly elevated serum bilirubin level per se does not inhibit hepatic uptake of Tc-IDA and does not preclude clinically useful scintigraphic examination.

Delayed open reduction of traumatic dislocation of the hip. A case report and historical review.

A surprisingly good functional result was achieved by open reduction in a 26-year-old woman with a neglected traumatic dislocation of the hip of fourteen months' duration. After six years the patient was completely symptom-free with a good range of movement and no radiologic evidence of avascular necrosis of the head of the femur. Review of the literature failed to reveal good long-term functional results, with supporting radiographs, of a similar case.

Central dislocations of the patella.

The rare traumatic condition of intra-articular dislocation of the patella in a 12-year-old boy is described, suffered in a fall, when he landed in a hole with his knee bent. Closed reduction by manipulation under general anesthesia failed because the upper pole of the patella was locked deeply in te intercondylar space. Operative reduction using a parapatellar incision in which the patella was levered into position without opening the capsule was followed by functional recovery.

Gallium-67 citrate scanning--a new adjunct in the detection and follow-up of extrapulmonary tuberculosis: concise communication.

Gallium-67 citrate scans were obtained in 11 patients considered at risk for extrapulmonary tuberculosis. Radiographic and bacteriologic studies were performed routinely and tissue biopsy selectively. Of five patients with proven extrapulmonary tuberculosis, there were three with renal tuberculosis, one with Pott's disease, and one with peritoneal tuberculosis. The Ga-67 scan correctly predicted presence or absence of active extrapulmonary foci in all 11 patients. Follow-up scans correlated well with clinical response to therapy. The diagnosis of extrapulmonary tuberculosis is often overlooked because of nonspecific symptoms and frequent lack of concurrent lung involvement. Scanning with Ga-67 citrate offers a reliable and simple means of screening patients at risk and of monitoring response to treatment.

Imaging the adrenal glands with radiolabeled inhibitors of enzymes: concise communication.

Although radioiodinated cholesterols furnished the first noninvasive imaging of the adrenal glands, it would be desirable to decrease the time for imaging and decrease the radiation dose. The relative tissue distributions of two radiolabeled enzyme inhibitors [3H] metyrapol and I-125-SKF-12185 were studied in dogs and man. Their percentage uptakes and target-to-nontarget ratios were similar. The adrenals of three dogs were imaged sharply at 2 hr after injection with 4--6 mCi of I-131-SKF-12185, confirmed by subsequent imaging with 1 mCi of I-131-6-beta-19-nor cholesterol at 5 days after injection. The use of 1 mCi of I-123-SKF will permit imaging of the adrenals in 1--2 hr and will decrease the radiation dose in the human to 0.76 rads to the adrenal, 0.18 rads to the ovaries and 1.7 rads to the liver.

An operator-independent method for background subtraction in adrenal-uptake measurements: concise communication.

A new computer program for adrenal-uptake measurements is presented in which the algorithm identifies the adrenal and background regions automatically after being given a starting point in the image. Adrenal uptakes and results of reproducibility tests are given for patients injected with [131I] 6beta-iodomethyl-19-norcholesterol. The data to date indicate no overlap in the percent-of-dose uptakes for normal patients and patients with Cushing's disease and Cushing's syndrome.

A new and superior adrenal imaging agent, 131I-6beta-iodomethyl-19-nor-cholesterol (NP-59): evaluation in humans.

We have reported tissue distribution studies in rats and dogs with a new adrenal imaging agent. 131I-6beta-iodomethyl-19-nor-cholesterol (NP-59). This agent concentrated five times higher in the adrenal cortex than 131I-19-iodocholesterol without increased concentration in non-adrenal tissues. We now report in 34 patients, the findings on scintigraphy with NP-59 compared with angiograms and/or adrenal vein hormone levels and histopathology, including 13 patients with hypercortisolism, 12 with primary aldosteronism, 2 with low renin hypertension, 5 with catecholamine excess, 1 with a liver metastasis from an aldosterone producing adrenal cortical carcinoma, and 1 with anaplastic adrenal cortical carcinoma. NP-59 adrenal cortical uptake was more rapid and intense and background activity was less prominent, allowing earlier and more definite interpretation of images than was possible with 131I-19-iodocholesterol.

Localization of radiolabeled enzyme inhibitors in the adrenal gland.

Tissue distribution studies were performed in rats and dogs at five time intervals between 10 min and 24 hr after the intravenous injection of one of the following radiolabeled adrenocortical enzyme inhibitors: 3H-amino-glutethimide, 125I-3-iodoaminoglutethimide, 3H-SKF-12185, 125I-3-SKF-12185, 3H-metyrapone. 3H-metyrapol. 3H-amphenone B, and 3H-SU-10603. In rats, 3H-SKF-12185 showed the highest uptake in the whole adrenal (3.5% kg dose/gm at 1 hr). In dogs, 3H-metyrapol showed the highest uptake in the adrenal cortex (9% kg dose/gm at 1 hr), and the peak cortex-to-liver concentration ratio was 57 at 2 hr. These peaks uptakes were comparable to those obtained with the conventional iodocholesterols, but they were reached much earlier, with elimination of most of the adrenal radioactivity by 24 hr. These properties would permit the use of 123I as the label and a higher tracer dose, resulting in a higher photon flux. Thus, the radiolabeled enzyme inhibitors show promise as adrenal-scanning agents, with a markedly shortened scanning procedure, a lower absorbed radiation dose, and better resolution.