sodium-pertechnetate-tc-99m and gallium-chloride

Ventilation distribution can be assessed by SPECT with Technegas. This study was undertaken in piglets with different degrees of ventilation inhomogeneity to compare PET using (68)Ga-labeled pseudogas or "Gallgas" with Technegas.. Twelve piglets were studied in 3 groups: control, lobar obstruction, and diffuse airway obstruction. Two more piglets were assessed for lung volume (functional residual capacity).. In controls, SPECT and PET images showed an even distribution of radioactivity. With lobar obstruction, the absence of ventilation of the obstructed lobe was visible with both techniques. In diffuse airway obstruction, SPECT images showed an even distribution of radioactivity, and PET images showed more varied radioactivity over the lung.. PET provides detailed ventilation distribution images and a better appreciation of ventilation heterogeneity. Gallgas with PET is a promising new diagnostic tool for the assessment of ventilation distribution.

Topics: Airway Resistance; Animals; Gallium; Gallium Radioisotopes; Lung; Lung Compliance; Methacholine Chloride; Muscarinic Agonists; Positron-Emission Tomography; Radiopharmaceuticals; Respiratory Mechanics; Sodium Pertechnetate Tc 99m; Swine; Tomography, Emission-Computed, Single-Photon

We retrospectively evaluated preoperative radioisotope (RI) scintiscans in 275 patients (283 glands) with parotid tumors who undergoing surgery between 1987 and 2000. Technetium-99m-pertechnetate (Tc) scintigraphy was conducted on 201 glands. Oncocytoma and Warthin's tumor showed a high positive rate. In evaluating Warthin's tumor with Tc scintigraphy, sensitivity was 75% and specificity 88%; above the age of 40 years, specificity exceeded 90%. Gallium-67-citrate (Ga) scintigraphy was conducted on 207 glands. Malignant parotid tumors showed high positivity (85%), but the specificity of positive findings was quite low (38%) because 44% of benign pleomorphic adenoma, which occupied major material, showed Ga-positive findings. Ga-negative findings indicated high probability (95%) of benign tumors. Thus, Tc scintigraphy is effective in diagnosing Warthin's tumor, while Ga scintigraphy is effective in diagnosing benign tumors.

Topics: Adenolymphoma; Adenoma, Oxyphilic; Adolescent; Adult; Aged; Aged, 80 and over; Female; Gallium; Humans; Male; Middle Aged; Parotid Gland; Parotid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m