Peter W. Blue

Effects of verapamil and diltiazem on gastric emptying in normal subjects.

It has been suggested that calcium-channel blockers may delay gastric emptying by inhibiting gastric smooth muscle contraction. Most reports in man, however, reveal no significant delay in gastric emptying after using nifedipine; other calcium-channel blockers have not been studied in humans to date. We studied the effects of verapamil and diltiazem on solid-phase gastric emptying in 10 healthy volunteers. Each subject underwent a radionuclide gastric emptying determination (1) without preadministered medication, (2) after verapamil 80 mg orally every 6 hr for 10 doses, and (3) after diltiazem 60 mg by mouth given as one dose. Results revealed no significant difference in gastric emptying rates after pretreatment with verapamil or diltiazem when compared with no premedication (P>0.37). We conclude that verapamil and diltiazem do not significantly delay gastric emptying in normal subjects. These data may be of clinical significance when prescribing calcium-channel blockers to patients with diseases associated with altered gastric emptying.

Case Report: Gallium-67 Uptake by the Thyroid Associated with Progressive Systemic Sclerosis

Although thyroidal uptake of gallium-67 has been described in several thyroid disorders, gallium-67 scanning is not commonly used in the evaluation of thyroid disease. Thyroidal gallium-67 uptake has been reported to occur frequently with subacute thyroiditis, anaplastic thyroid carcinoma, and thyroid lymphoma, and occasionally with Hashimotos thyroiditis and follicular thyroid carcinoma. A patient is described with progressive systemic sclerosis who, while being scanned for possible active pulmonary involvement, was found incidentally to have abnormal gallium-67 uptake only in the thyroid gland. Fine needle aspiration cytology of the thyroid revealed Hashimotos thyroiditis. Although Hashimotos thyroiditis occurs with increased frequency in patients with progressive systemic sclerosis, thyroidal uptake of gallium-67 associated with progressive systemic sclerosis has not, to our knowledge, been previously described. Since aggressive thyroid malignancies frequently are imaged by gallium-67 scintigraphy, fine needle aspiration cytology of the thyroid often is essential in the evaluation of thyroidal gallium-67 uptake.

Radionuclide Demonstration of a Renopleural Fistula Following Trauma

A renopleural fistula was detected on a Tc-99m DTPA renal study during evaluation for possible post-traumatic urinoma.

Diffuse Radioiodine Lung Uptake in Miliary Thyroid Carcinoma Metastases

A diffuse pattern of homogeneous tracer uptake is seen by 1-131 scintigraphy in a patient with widespread miliary lung metastases due to papillary thyroid carcinoma. This case report emphasizes the need to include metastatic thyroid carcinoma in the differential diagnosis of miliary lung nodules.

Gas washout and pressure waveform characteristics of high-frequency oscillation.

High-frequency oscillation (HFO) minimizes tidal volume. To investigate whether ventilation can proceed when tidal movement (volume) is eliminated, a nondis-tensible physical model of interconnected chambers was constructed. During HFO, ventilation was related to pressure waveform characteristics recorded within the separate chambers. Ventilation increased up to a critical frequency related to the time constant of the system. Beyond this frequency, ventilation dropped off rapidly.

Duodenogastroesophageal reflux. Demonstration with Tc-99m DISIDA imaging.

Duodenogastroesophageal reflux is demonstrated using cholescintigraphy in a patient with severe esophagitis.

GLOMERULAR FILTRATION RATE DETERMINED IN CONJUNCTION WITH ROUTINE RENAL SCAN

A method has been developed to estimate glomerular filtration rate (GFR) by means of computer evaluation of information obtained during routine renal scanning with intravenous Tc-99m DTPA. Thirty minutes of data were accumulated as a 30 sec/frame dynamic study following injection, with kidneys and a portion of the heart included in the imaging field. From the computer acquired study, a plasma activity disappearance curve was generated using: (1) a region of interest outlining the imaged portion of the heart, and (2) a single blood sample obtained near the end of the study. Average plasma activity concentration during the study (PAVG) was then determined. Total urinary activity (TUA) generated from onset to conclusion of the study at time T, was determined using subsequent pre- and post-void bladder images, and measured volume and activity of the voided urine. Clearance was calculated using the formula: C1 (ml/min) = TUA DTPA (PAVG)(T) The urinary radionuclide clearance correlated highly with standard 24-hour creatinine clearance over a wide range of clearance values in thirteen patients. The method described to estimate GFR can be performed using less than 40 minutes of imaging time, requires only a single blood sample, does not require measurement of administered dose, is accurate even when the dose is partially or largely infiltrated, and unlike many popular indirect methods for estimating GFR adequately accounts for variations in volume of distribution.

Intraparenchymal Perirenal Pseudocyst Following Trauma

Perirenal pseudocyst (urinoma) is an extravasated collection of urine usually resulting from trauma. The unusual occurrence of the intrarenal location of a pseudocyst is herein first reported.

Masked Obstruction of the Renal Collecting System

Two cases of apparent unilateral renal obstruction in which lesser contralateral obstructions were not seen are presented. In both cases, relief of the more severe obstruction resulted in an unmasking of the milder contralateral lesion.

Differential diagnosis of prolonged cortical retention of radiotracer in technetium-99m DTPA renal scintigraphy.

The mechanisms of prolonged renal cortical tracer retention in Tc-99m DTPA scintigraphy are discussed and a variety of examples are presented.