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Abstract Background 99mTc-macroaggregated albumin (99mTc-MAA) scintigraphy is utilized in treatment planning for Yttrium-90 (90Y) Selective Internal Radiation Therapy (SIRT) of liver tumors to evaluate hepatopulmonary shunting by calculating the lung shunt fraction (LSF). The purpose of this study was to evaluate if LSF calculation using SPECT/CT instead of planar gamma camera imaging is more accurate and if this can potentially lead to more effective treatment planning of hepatic lesions while avoiding excessive pulmonary irradiation. Results LSF calculation was obtained using two different methodologies in 85 cases from consecutive patients intended to receive 90Y SIRT. The first method was based on planar gamma camera imaging in the anterior and posterior views with geometric mean calculation of the LSF from regions of interest of the liver and lungs. The second method was based on segmentation of the liver and lungs from SPECT/CT images of the thorax and abdomen. The differences in planar imaging versus SPECT/CT derived LSF values along with the estimated absorbed lung mean dose (LMD) were evaluated. The LSF values were higher in planar imaging versus SPECT/CT in 81/85 cases, with a mean value of 8.5% vs. 4.6% respectively; the difference was statistically significant using a paired t-test (alpha = 0.05). In those patients who received SIRT, the estimated absorbed LMD calculated with planar imaging was significantly higher than with SPECT/CT (t-test, P

Background: Substantial inter-observer variation has been documented in the recognition and description of specific sonographic features as well as for ATA sonographic risk (ASR). This raises the question if the risk stratification proposed by the ATA guidelines is reproducible and applicable for nodules with indeterminate cytology. The aim of the study was to determine the inter-reader agreement (IRR) among radiologists using the 2015 ASR stratification in indeterminate thyroid nodules. Methods: Three board certified radiologists who were blinded to clinical data and to each other, interpreted the ultrasound findings of 179 nodules that had Bethesda III cytology. The nodules were classified into high suspicion (HS), intermediate (IS), low (LS), very low (VLS). Echogenicity, composition, shape taller than wide, vascularity, type of margins, presence and type of calcifications were also described. Results: The majority consensus revealed that 28%, 27%, 39% and 5% were described as high, intermediate, low and very low ASR, respectively. The inter-reader agreement was near perfect (k 0.82 CI 95% (0.77–0.87)). Nodules were paired into a higher risk (HS + IS) and lower risk (LS + VLS) categories with substantial agreement (k 0.7) in both categories. Conclusion: A near perfect agreement among readers was observed when stratifying indeterminate cytology nodules for ASR.

Introduction. Although whole body scan (WBS) with I-131 is a highly sensitive tool for detecting normal thyroid tissue and metastasis of differentiated thyroid cancer (DTC), it is not specific. Additional information, provided by single photon emission computed tomography combined with X-ray computed tomography (SPECT/CT) and by the serum thyroglobulin level, is extremely useful for the interpretation of findings. Case Presentation. We report four cases of false positive WBS in patients with DTC: ovarian uptake corresponding to an endometrioma, scrotal uptake due to a spermatocele, rib-cage uptake due to an old fracture, and hepatic and renal uptake secondary to a granuloma and simple cyst, respectively. Conclusions. Trapping, organification, and storage of iodine are more prominent in thyroid tissue but not specific. Physiologic sodium-iodine symporter expression in other tissues explains some, but not all, of the WBS false positive cases. Other proposed etiologies are accumulation of radioiodine in inflamed organs, metabolism of radiodinated thyroid hormone, presence of radioiodine in body fluids, and contamination. In our cases nonthyroidal pathologies were suspected since the imaging findings were not corroborated by an elevated thyroglobulin level, which is considered a reliable tumor marker for most well-differentiated thyroid cancers. Clinicians should be aware of the potential pitfalls of WBS in DTC to avoid incorrect management.