Damir Dodig

Ultrasonographic Differentiation of Benign From Malignant Neck Lymphadenopathy in Thyroid Cancer

Objective. The aim of this study was to determine whether ultrasonography itself was able to distinguish benign from malignant lymphadenopathy in patients with thyroid cancer. Methods. We evaluated lymph nodes in a group of patients with thyroid cancer. Nodes were detected and measured by ultrasonography, and their shape, echogenicity, size, and location were noted. Ultrasonographically guided fine‐needle aspiration biopsy (FNAB) was performed, and smears were analyzed cytologically. Results. Ultrasonographically guided FNAB was performed in 578 neck nodes in a group of 631 patients with thyroid cancer. In most cases, metastases had a round shape and various echo structures, with a predomination of hypoechoic nodes without a hilum. There were statistical differences in size between metastatic and benign nodes in terms of maximum diameter, minimum diameter, and volume. Among these, minimum diameter and the shape of the nodes seemed to be the most reliable in suggesting malignancy. A round shape with a longitudinal/transverse ratio of less than 2 of hypoechoic nodes indicated the presence of metastases, and we then performed FNAB. The absence of an echogenic hilum and the presence of cystic portions and calcifications were significantly greater in malignancies than in benign lesions (P < .001). In most cases, metastatic nodules were situated in the lower third of the neck. Reactively enlarged nodes occurred more frequently in the upper part of the neck. Conclusions. Ultrasonography itself cannot distinguish benign from malignant lesions, but an echographic appearance suggests malignancy and helps in the selection of the node to aspirate with ultrasonographically guided FNAB, which is crucial for a final diagnosis.

Radioiodine uptake in thyroid cancer patients after diagnostic application of low-dose 131I

The aim of this study was to investigate the influence of the diagnostic administration of 74 MBq 131I on subsequent uptake of therapeutic radioiodine in thyroid cancer patients. Retention measurements were performed using a whole-body counter in 24 patients 6 weeks after total thyroidectomy. Profile scans were performed 2, 24, 48 and 72 h after the administration of the diagnostic dose and 72 h after the administration of the ablation-therapeutic dose (4.4 GBq). The mean ( +/- S.D.) effective half-life of the diagnostic dose in thyroid remnants was 40.3 +/- 23.0 h. The uptake in the thyroid remnants of the subsequent ablation dose 72 h after administration was 30.4 +/- 19.8% of that predicted from the diagnostic study. The greater reduction in uptake was associated with the longer half-life of iodine and higher uptake in the thyroid remnants at 24 h, with a longer interval between surgery and administration of the diagnostic dose and a shorter period between administration of the diagnostic and ablation doses. Our results show that a diagnostic dose of 74 MBq 131I markedly reduces thyroid uptake of an ablation dose of 131I. This should be taken into account during radiation dose planning whenever a quantitative dosimetric study is to be performed.

Effect of imaging time on the values of the sacroiliac index

AbstractQuantitative scintigraphy of the sacroiliac joints was performed in a group of normal subjects and a group of subjects with unilateral and bilateral sacroiliitis. The aim of the study was to determine whether the time intervals of imaging had any effect on the values of the sacroiliac index. Imaging was performed every 30 min up to 300 min and the indices were calculated at the time intervals mentioned. We found that the values of the sacroiliac index increased in the group of normal subjects until 150 min after the application of the radiopharmaceutical, and that in the group of subjects who had sacroiliitis they increased until 210 min. The results show that the time interval optimal to quantitative sacroiliac joint imaging is at least

Thyroid remnant ablation in patients with papillary cancer: a comparison of low, moderate, and high activities of radioiodine.

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Sandstorm image: bone scintigraphy in pulmonary alveolar microlithiasis.

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Bone marrow immunoscintigraphy in haematological patients with pancytopenia: preliminary results.

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Tc-99m DTPA renal scintigraphy using deconvolution analysis with six functional images of the mean time to evaluate acute pyelonephritis.

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Determination of small objects from pinhole scintigrams

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