Fluorine-18-fluorodihydroxyphenylalanine Positron-emission Tomography Scans of Neuroendocrine Tumors (Carcinoids and Pheochromocytomas).

Objectives: Conventional methods of imaging neuroendocrine tumors with computed tomography, magnetic resonance imaging, indium-111-octreotide, or radiolabeled metaiodobenzilguanidine scintigraphy have limitations. This pilot study tried to improve the localization of these tumors with fluorine-18-fluorodihydroxyphenylalanine (F-DOPA) positron-emission tomography (PET) scanning.

Materials And Methods: We studied 22 patients, the majority of whom were referred with clinical diagnosis or suspicion of carcinoid ( = 11), neuroendocrine tumors ( = 7) or pheochromocytoma/paraganglioma (PGL) ( = 4).

Correlation of a scintigraphic pulmonary perfusion index with hemodynamic parameters in patients with pulmonary arterial hypertension.

Purpose: To determine whether the perfusion index (PI) can be used as a noninvasive measure to diagnose and predict the severity of disease in patients with pulmonary arterial hypertension (PAH).

Materials And Methods: Twenty-two patients were included in this retrospective investigation: 9 controls and 13 patients with PAH. Controls had no evidence of PAH [mean pulmonary arterial pressure (MPAP) ≤25 mm Hg and pulmonary capillary wedge pressure ≤18 mm Hg].

False-positive FDG-PET imaging of the thymus of a child with Hodgkin's disease.

During the evaluation of a child who had completed treatment for Hodgkin's disease, a PET study strongly suggested recurrent disease in the mediastinum. Biopsies were obtained and revealed normal thymic tissue only, with no evidence of recurrent disease. The ongoing difficulty in establishing accurate disease status in patients treated for Hodgkin's disease is discussed, along with recommendations for treating pediatric patient populations.

Comparative nigrostriatal dopaminergic imaging with iodine-123-beta CIT-FP/SPECT and fluorine-18-FDOPA/PET.

Unlabelled: SPECT imaging of the dopamine transporter is now an alternative to PET in the quantification of nigrostriatal dopaminergic function. We compared [123I] beta CIT-FP/SPECT and [18F]FDOPA/PET in the assessment of nigrostriatal dopaminergic function in Parkinson's disease (PD) and normal aging.

Methods: We studied 12 mildly affected PD patients (mean age: 61.

Quantitative renal blood flow in urinary tract obstruction.

Technetium-labeled red blood cell scintigraphy using a bolus injection was used to obtain a noninvasive quantitative measurement of renal blood flow. The method used is an adaptation of the one used for calculating cerebral blood flow which involves deconvolution of the first pass of the isotope through the kidneys. The relative renal blood flow of 18 normal patients and 18 patients with unilateral urinary tract obstruction was performed.

Radionuclide assessment of the effects of chest physical therapy on ventilation in cystic fibrosis.

This study assesses the use of krypton 81m scintigraphy as a measurement tool in evaluating the effectiveness of bronchial drainage with percussion and vibration on peripheral ventilation in patients with cystic fibrosis. Ten patients with cystic fibrosis participated. Each patient underwent a krypton 81m ventilation study and traditional pulmonary function tests.

Iridium- 191 angiocardiography for the detection and quantitation of left-to-right shunting.

An osmium- 191 leads to iridium- 191 generator that can deliver multiple doses of Ir- 191m for first-pass radionuclide angiography has been developed. Iridium- 191m has a physical half-life of 4.96 sec and decays with emission of 65-keV and 129-keV photons in 58 and 30% abundance, respectively.