Clinical validation of synthetic brain MRI in children: initial experience.

INTRODUCTION: The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. METHODS: Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. RESULTS: Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. CONCLUSIONS: Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted.

Response of thyroglobulin to radioiodine therapy in thyroglobulin-elevated negative iodine scintigraphy (TENIS) syndrome.

BACKGROUND: While radioiodine (131-I) is widely used in the treatment of differentiated thyroid cancer, its role remains less certain when abnormal 131-I uptake cannot be demonstrated in a pre-therapy diagnostic scan. Documentation of abnormal 131-I uptake in a post-therapy scan in such cases helps to justify the radioiodine therapy, but the post-therapy scan can remain persistently negative. AIM: To evaluate (i) whether 131-I therapy had any measurable effect on thyroglobulin (Tg) levels in patients who were scan negative prior to radioiodine therapy and remained scan negative after therapy, and (ii) whether the magnitude of the effect on Tg depended on the pre-therapy Tg level. PATIENTS AND METHODS: Retrospective analysis of 78 patients. All patients had pre-therapy and post-therapy Tg levels measured under stimulation with thyroid stimulating hormone. Hospital data until date of last contact were analyzed to assess for recurrent disease. RESULTS: Tg levels decreased by 55% in those having Tg 10 µg/l or higher; and by 41% in those with less than 10 µg/l. In patients with detectable Tg antibodies, there were no statistically significant decreases demonstrated for either Tg or Tg antibody levels. CONCLUSION: Radioiodine therapy can reduce Tg levels, independently of the pre-therapy level, even when the pre-therapy level is low and the pre-therapy, as well as the post-therapy, radioiodine scan remains negative.