EWING TUMOR OF THE MANDIBLE

A primary Ewing's tumor in the mandible is reported, and the diagnostic imaging features of this lesion are discussed. Modalities used included panoramic and plain films, computed tomography, and Tc-99m-MDP scintigraphy

EWING TUMOR OF THE MANDIBLE

A primary Ewing's tumor in the mandible is reported, and the diagnostic imaging features of this lesion are discussed. Modalities used included panoramic and plain films, computed tomography, and Tc-99m-MDP scintigraphy

The effect of allopurinol pretreatment on intestinal hypoperfusion encountered after correction of intestinal volvulus

After reversal of blood flow following a prolonged period of ischemia, blood flow returns for a few seconds and is reduced afterward. This is called ''no-reflow phenomenon.'' Antioxidants such as allopurinol have been shown to prevent the occurrence of this phenomenon in organs other than the intestine. An experimental study was conducted to investigate the effect of allopurinol pretreatment on intestinal blood flow after correction of intestinal volvulus in rabbits. In group 1, baseline intestinal blood flow (IBF) was evaluated using radiolabeled red blood cells. In group 2, 720 degrees intestinal volvulus was created and IBF was evaluated 6 hours later. In group 3, intestinal volvulus was created and devolvulus was performed 6 hours later. Intraperitoneal isotonic saline was injected 60 minutes before correction of the volvulus. IBF was evaluated after correction of the volvulus. Group 4 had the same procedures as group 3, but allopurinol (200 mg/kg) was injected in place of the isotonic saline. IBF stopped 6 hours after volvulus. Compared with the baseline group, IBF was significantly lower in the group with volvulus + devolvulus (P < .01). The IBF of the allopurinol-treated group was significantly higher than that of the isotonic saline group (P < .01) and it did not differ significantly from that of the baseline group. Histopathological examination showed that intestinal volvulus leads to histological injury. The histological injury was more pronounced in the devolvulus group and was less severe in the allopurinol group in comparison to the isotonic saline pretreatment group (P < .01). It is concluded that allopurinol pretreatment prevents the intestinal hypoperfusion (no-reflow phenomenon) and histological injury encountered after correction of intestinal volvulus of 6 hours' duration. Copyright (C) 1996 by W.B. Saunders Compan

Early and delayed thallium-201 scintigraphy in thyroid nodules: The relationship between early thallium-201 uptake and perfusion

Seventy-six patients with thyroid nodules were studied. Initially, 74 MBq of thallium-201 was injected. The thyroid gland was imaged 15 min (early) and 3 h (delayed) after the injection. Thereafter, 185 MBq technetium-99m pertechnetate was injected. Immediately after the injection, a 1-min perfusion image was acquired, followed by an image at 20 min. Increased early and delayed Tl-201 uptake compared with the contralateral thyroid tissue was adopted as the criterion for malignancy. Sensitivity, specificity and negative predictive values were found to be 85%, 64% and 78%, respectively, in operated patients, but these values were 86%, 87% and 95 %, respectively, in the whole group, including patients followed with fine-needle aspiration biopsy. With the purpose of investigating the relationship between perfusion and early Tl-201 uptake, both perfusion and early images were graded comparing nodular activity with contralateral thyroid activity. There was a poor correlation between perfusion and Tl-201 uptake. The correlation was even worse in hyperactive nodules. It is concluded that early and delayed Tl-201 imaging should not be used in the differential diagnosis of cold nodules and that early Tl-201 uptake seems to be more closely related to factors other than perfusion