Background: Thyroid nodules are a common finding, especially in iodine-deficient regions. Ultrasonographic scoring systems such as Thyroid Imaging Reporting And Data System (TIRADS) are helpful in differentiating between benign and malignant thyroid nodules by offering a risk stratification model. Depending on the constellation or number of suspicious ultrasound features, a fine needle biopsy (FNB) is recommended. However, none of the previously published TIRADS considered the functional status of the nodules. Hyperfunctioning thyroid nodules (HTN) were presumed to exclude malignancy with a very high negative predictive value. Particularly in regions where the iodine supply is lower, the majority of HTN are seen in patients with normal TSH levels. Therefore, thyroid scintigraphy is essential for the detection of HTN. We investigated whether TIRADS identifies HTN as non-suspicious. Methods: We evaluated 615 HTN (23.2±10.0 mm at maximum diameter in 582 patients (n = 442 female, 57.7±13.2 years, and n = 140 male, 60.1 ±12.7 years) detected by ^99mTc Pertechnetate or ¹²³Iodine scintigraphy. Prior to evaluating the scintigraphic appearance, all nodules were analyzed prospectively with sonography, using the TIRADS model referenced in Kwak et al., wherein fine needle biopsy is recommended for TIRADS 4A or higher. We also investigated two subgroups, 42 nodules with available histology as well as 117 patients with subclinical or overt hyperthyroidism. Results: Whereas 15.9% of the nodules were classified as TIRADS 3 or lower and <0.1% as TIRADS 5, most of the nodules were classified as TIRADS 4A (29.3%), 4B (29.3%), and 4C (24.9%), respectively. Altogether, more than 80% of the autonomous thyroid nodules were classified as TIRADS 4A or higher which would result in a recommendation of fine needle biopsy. Focusing on those 117 HTN that were already associated with hyperthyroid laboratory values, the rates were similar: 81.2% were categorized as TIRADS 4A or higher (4A: 33.3%, 4B: 29.9%, 4C:17.1%, 5: 0.9%). In the subgroup of patients who underwent thyroid surgery, all nodules were benign, confirming the known NPV of HTN with regard to malignancy exclusion. Conclusion: Integration of thyroid scintigraphy into the TIRADS model is essential to prevent unnecessary FNB and thyroid surgery.

Germany has a long history of insufficient iodine supply and thyroid nodules occur in over 30% of the adult population, the vast majority of which are benign. Non-invasive diagnostics remain challenging, and ultrasound-based risk stratification systems are essential for selecting lesions requiring further clarification. However, no recommendation can yet be made about which system performs the best for iodine deficiency areas. In a German multicenter approach, 1211 thyroid nodules from 849 consecutive patients with cytological or histopathological results were enrolled. Scintigraphically hyperfunctioning lesions were excluded. Ultrasound features were prospectively recorded, and the resulting classifications according to five risk stratification systems were retrospectively determined. Observations determined 1022 benign and 189 malignant lesions. The diagnostic accuracies were 0.79, 0.78, 0.70, 0.82, and 0.79 for Kwak Thyroid Imaging Reporting and Data System (Kwak-TIRADS), American College of Radiology (ACR) TI-RADS, European Thyroid Association (EU)-TIRADS, Korean-TIRADS, and American Thyroid Association (ATA) Guidelines, respectively. Receiver Operating Curves revealed Areas under the Curve of 0.803, 0.795, 0.800, 0.805, and 0.801, respectively. According to the ATA Guidelines, 135 thyroid nodules (11.1%) could not be classified. Kwak-TIRADS, ACR TI-RADS, and Korean-TIRADS outperformed EU-TIRADS and ATA Guidelines and therefore can be primarily recommended for non-autonomously functioning lesions in areas with a history of iodine deficiency.

Due to the widespread use of ultrasound, small thyroid nodules (TNs) ≤ 10 mm are common findings. Standardized approaches for the risk stratification of TNs with Thyroid Imaging Reporting and Data Systems (TIRADS) were evaluated for the clinical routine. With TIRADS, the risk of malignancy in TNs is calculated by scoring the number or combination of suspicious ultrasound features, leading to recommendations for further diagnostic steps. However, there are only scarce data on the performance of TIRADS for small TNs. The aim was to compare three different TIRADS for risk stratification of small TNs in routine clinical practice. We conducted a retrospective cohort analysis of TNs ≤ 10 mm and their available histology. Nodules were classified according to three different TIRADS. In the study, 140 patients (n = 113 female) with 145 thyroid nodules (n = 76 malignant) were included. Most of the malignant nodules were papillary carcinoma (97%), and the remaining 3% were medullary carcinoma. For all tested TIRADS, the prevalence of malignancy rose with increasing category levels. The highest negative predictive value was found for ACR TI-RADS and the highest positive predictive value for Kwak-TIRADS. All tested variants of TIRADS showed comparable diagnostic performance for the risk stratification of small TNs. TIRADS seems to be a promising tool to reliably assess the risk of malignancy of small TNs.

OBJECTIVE. The purpose of this study is to compare functional MR urography (MRU) with the results of ultrasound and radionuclide 99mTc-mercaptoacetyltriglycine (MAG3) scintigraphy in evaluating morphologic findings, split renal function, and urinary tract obstruction in pediatric patients. MATERIALS AND METHODS. Pediatric patients with proven congenital anomalies of the kidney and urinary tract were included (n = 112). The morphologic findings of MRU were compared with previous diagnostic ultrasound findings. For evaluation of split renal function and urinary tract obstruction, MAG3 scintigraphy was used as a reference standard. RESULTS. MRU provided detailed morphologic information of the whole urinary tract for all 112 patients. In 94.6% of cases (n = 106), diagnostic findings could be verified, and in 5.4% of cases (n = 6), more detailed information could be gained. Equivalent split renal function showed good concordance between functional MRU and MAG3 scintigraphy. However, in kidneys with restricted ...

PET/CT with prostate-specific membrane antigen (PSMA)-targeted tracers has been used in the diagnosis and staging of patients with clear cell renal cell carcinoma (ccRCC). For ccRCC primary tumors, PET parameters were shown to predict histologic grade and features. The aim of this study was to correlate PSMA PET/CT with histopathological findings in patients with metastatic recurrence of ccRCC. Patients with ccRCC who underwent PSMA-targeted PET/CT and subsequent histopathological evaluation of suspicious lesions were included. Specimens underwent immunohistochemical marking. Lesion diameter, volume and tracer uptake were correlated with the extent and intensity of molecular PSMA expression and with clinical findings. Twelve PET-positive lesions of nine patients were evaluated. Eleven ccRCC metastases and one prostate carcinoma were detected histopathologically. Molecular PSMA expression was detected in all lesions, which intensity and distribution did not correlate with PET parameters. PSMA-targeted PET/CT is a feasible tool for the evaluation of patients with ccRCC but cannot reliably predict histologic features of metastases. PSMA may also be expressed in malignant lesions other than ccRCC, leading to incidental detection of these tumors.