The effect of an iodine restricted including no sea foods diet, on technetium-99m thyroid scintigraphy: A neglected issue in nuclear medicine practice

Although it is recommended to patients to avoid sea food and iodine-containing medications prior to iodine-131 ( 131I) scanning, the efficacy of this diet as for technetium-99m pertechnetate ( 99mTc-P) thyroid scintigraphy is not well addressed in the literature. We evaluated a self-managed, outpatients, iodine restricted diet (IRD) designed to reduce total body iodine in preparation for such a scan. We have studied 39 patients who referred to our Department for multinodular goiter, 30 females and 9 males, aged: 14-54 years and their 99mTc-P thyroid scintigraphy showed poor visualization of the thyroid gland. These patiens were living in regions with high consumption of sea foods went underwent a two-weeks iodine restriction including restriction of sea food diet for the reduction of iodine body content. These patients were called for a repeated scan after going on a IRD for at least two weeks. The two scans were compared visually, and by semiquantitative analysis. Semiquantitative analysis was applied in 8 regions of interest (ROI) by using Wilcoxon signed rank test. Thirty-six subjects had better quality scintigraphy images in the post IRD thyroid scan, as was visually assessed by two nuclear medicine physicians. Semiquantitatetively, there was a significant difference in the mean counts of ROI of the right and the left thyroid lobes in favor of the post IRD scans (P<0.05). In conclusion, this study suggests that in patients with multinodular goiter, living in regions with high consumption of sea foods a two-weeks diet for the reduction of iodine body content induces in most of the cases a slightly better diagnostic thyroid 99mTc-P scan

The diagnostic value of 99mTc-IgG scintigraphy in the diabetic foot and comparison with 99mTc-MDP scintigraphy

Diabetic foot infection is the most common etiology of nontraumatic amputation of the lower extremities, and early diagnosis is of great importance in its management. The aim of this prospective study was to evaluate the strength of 99mTc-IgG scintigraphy in diagnosis of osteomyelitis of the diabetic foot and to compare 99mTc-IgG scintigraphy with 99mTc-methylene diphosphonate (MDP) scintigraphy. Methods: A prospective university hospital-based study was performed over 24 mo. Eighteen patients with type II diabetes and foot ulcers (15 men and 3 women; age range, 45-80 y) were referred for imaging because of clinically suspected osteomyelitis. Early (5-h) and late (24-h) 99mTc-IgG scanning and 3-phase skeletal scintigraphy were completed for all patients at a 3- to 4-d interval. Regions of interest over the involved bony sites and the contralateral normal sites were drawn, and the abnormal-to-normal ratios were acquired for both 99mTc-IgG and 99mTc-MDP studies. Results: From a total of 23 lesions, we observed 10 sites of osteomyelitis, 10 sites of cellulitis, and 3 sites of aseptic inflammation confirmed by MRI, clinical presentation, histopathologic examination, and follow-up evaluation as a gold standard. Both 99mTc-IgG and 99mTc-MDP scanning showed excellent sensitivity for diagnosis of osteomyelitis, but the specificity was significantly lower (69.2% and 53.8%, respectively). Sensitivity, specificity, and accuracy in the diagnosis of osteomyelitis were, respectively, 100%, 53.8%, 73.9% for 99mTc-MDP scanning; 100%, 69.2%, 82.6% for 5-h 99mTc-IgG scanning; and 60%, 76.9%, 69.5% for 24-h 99mTc-IgG scanning. There was no significant difference between the semiquantitative indices of 5-h and 24-h 99mTc-IgG scanning for inflammation, cellulitis, and osteomyelitis. Conclusion: Although both 99mTc-IgG and 99mTc-MDP scintigraphy have high sensitivity for the diagnosis of osteomyelitis, the specificity of these studies is poor. For 99mTc-IgG scintigraphy, 5-h images appear to be adequate, and there is little benefit to performing additional imaging at 24 h. © 2011 by the Society of Nuclear Medicine, Inc

The assessment of relation between presence of side effects resulting from dipyridamole injection during myocardial perfusion imaging with hemodynamic changes, electrocardiographic and scan findings

Aim: Evaluation the prevalence of side effects due to dipyridamole injection, during myocardial perfusion imaging, and their correlation with hemodynamic changes and scan findings . Materials & Methods: Before starting the stress phase myocardial perfusion imaging , electrocardiogram, blood pressure and heart rate of all the patients were registered and then, dilute dipyridamole amounting to 0.568 mg/kg in 10 ml of normal saline was infused within 4 minutes . Within the period of infusion, the patient's electrocardiogram, HR, SBP, DBP, and any complaint of them was recorded. Results: In this study, we examined 590 patients (Mean ± SD; 57 ± 11 year old), who performed myocardial perfusion scan with intravenous dipyridamole in stress phase. In order to assessment the relation between side effects, hemodynamic response to dipyridamole infusion, myocardial perfusion imaging , and electrocardiographic findings , we evaluated resting and post‐infusion changes of HR, SBP, DBP. There is no significant difference in mean ± SD of resting HR (82 ± 12 beat/minute, vs 82 ± 10 beat/minute; p > 0.05), resting DBP (79 ± 9 mmHg ,vs 79 ± 10 mmHg; p> 0.05), and stress SBP (132 ± 20 mmHg vs 131 ± 23 mmHg ; p > 0.05) in patients without and with symptoms. However, significant difference in mean ± SD of post‐infusion HR (88 ± 13 beat/minute, vs 92 ± 10 beat/minute ; p = 0.016), rest SBP (139 ± 20 mmHg, vs 133 ± 23 mmHg ; p = 0.024), stress DBP (76 ± 9 mmHg ,vs 72 ± 10 mmHg ; p = 0.003), were noted in patients with and without symptoms. Conclusion: Our data demonstrated that most of side effects are self limiting and occur in patients with basic abnormalities in their ECG and scan findings