[Diagnostic reliability of ultrasonography in the preoperative staging of the N parameter in head and neck neoplasms]. / Attendibilità diagnostica dell'ecotomografia nella stadiazione preoperatoria del parametro N nelle neoplasie del capo-collo.

The demonstration of metastatic involvement of neck nodes is a crucial step in the staging of patients with head and neck tumors. Diagnostic accuracy, sensitivity, and specificity of US in the detection of lymph node metastases were evaluated in 48 patients with this type of malignancy. The patients subsequently underwent surgical node dissection. Comparison of US, clinical and histological data demonstrated US to have 93.7% diagnostic accuracy, 100% sensitivity, and 84% specificity--the corresponding clinical values being 81%, 79%, and 84%, respectively. Among several US parameters, a substantial role in differentiating metastatic from tumor-free lymph nodes was played by the evaluation of roundness index (RI), and by the demonstration of an intranodal hyperechoic stria: RI value was always higher than 2 in tumor-free nodes and the hyperechoic stria was always absent in metastatic nodes. US approach never failed to demonstrate metastatic nodes while clinics missed them in 6 patients. Thus, US appears the most valuable diagnostic tool for staging head and neck tumors; its diagnostic accuracy can be increased by the combination with US-guided aspiration biopsy.

[A comparative evaluation of iodine-131 OIH and technetium-99m MAG3 in the study of renal function]. / Valutazione comparata di Iodio-131 OIH e Tecnezio-99m MAG3 nello studio della funzionalità renale.

A new renal imaging agent, 99mTc mercaptoacetyltriglycine (MAG3), has been recently proposed in the nuclear medicine evaluation of renal function. Just like 131 orthoiodohippurate (OIH), 99mTc MAG3 is removed mainly by the renal tubules. An heterogeneous group of 39 patients underwent a radioisotopic study with the simultaneous injection of OIH (131I) and 99mTc MAG3. Image quality was found to be better with 99mTc MAG3 than with OIH (131I), because the former always allowed renal regions of interest (ROI) to be clearly demonstrated, even in case of severe renal impairment. A quantitative analysis was also carried out: effective renal plasma flow (ERPF) values were compared with renographic peak times evaluated by using both radiotracers. Our results demonstrate a firm correlation to exist between the informative content yielded by 99mTc MAG3 and by OIH (131I). Absolute ERPF value was higher with MAG3, but the correlation index (r = 0.98) allowed a simple correction factor to be introduced. In conclusion, MAG3 appears to be a good alternative to OIH.