Faculty Bibliography

BACKGROUND:Nondiagnostic cytology for thyroid nodules, consistent with The Bethesda System for Reporting Thyroid Cytopathology category I (B1) poses a management dilemma for clinicians. The objective of this study was to define the malignancy risk of nodules with B1 cytology using American College of Radiology Thyroid Imaging Reporting & Data System (TI-RADS) and to assess whether TI-RADS can help guide the decision to perform a repeat biopsy of these nodules. MATERIALS AND METHODS/METHODS:This retrospective cohort study evaluated 139 B1 nodules that had a definitive diagnosis on repeat biopsy or surgical excision. Sonographic features were evaluated and classified according to TI-RADS. TI-RADS category and total points were compared to the final diagnosis to determine the malignancy risk of B1 thyroid nodules. RESULTS:Of the 139 nodules, 11 (7.9%) were malignant. The malignancy risk of nodules assigned TI-RADS category 1 and 2 were both 0%, TI-RADS 3 was 2.9%, whereas TI-RADS 4 and 5 were 5.9% and 46.2%, respectively. The optimal cutoff for TI-RADS points predicting malignancy was 5 points. CONCLUSION/CONCLUSIONS:B1 thyroid nodules in TI-RADS categories 1-3 may not require repeat biopsy given low malignancy risk. However, B1 nodules in TI-RADS categories 4 and 5 have a higher malignancy risk and thus should undergo repeat biopsy.

OBJECTIVE:The aim of the study is to evaluate the performance of the ovarian-adnexal reporting and data system magnetic resonance imaging (O-RADS MRI) score and perform individual MRI feature analysis for differentiating between benign and malignant ovarian teratomas. METHODS:In this institutional review board-approved retrospective study, consecutive patients with a pathology-proven fat-containing ovarian mass imaged with contrast-enhanced MRI (1.5T or 3T) from 2013 to 2022 were included. Two blinded radiologists independently evaluated masses per the O-RADS MRI lexicon, including having a "characteristic" or "large" Rokitansky nodule (RN). Additional features analyzed included the following: nodule size/percentage volume relative to total teratoma volume, presence of bulk/intravoxel fat in the nodule, diffusion restriction in the nodule, angular interface, nodule extension through the teratoma border, presence/type of nodule enhancement pattern (solid versus peripheral), and evidence for metastatic disease. An overall O-RADS MRI score was assigned. Patient and lesion features associated with malignancy were evaluated and used to create a malignant teratoma score. χ2, Fisher's exact tests, receiver operating characteristic curve, and κ analysis was performed. RESULTS:One hundred thirty-seven women (median age 34, range 9-84 years) with 123 benign and 14 malignant lesions were included. Mean teratoma size was 7.3 cm (malignant: 14.4 cm, benign: 6.5 cm). 18/123 (14.6%) of benign teratomas were assigned an O-RADS 4 based on the presence of a "large" (11/18) or "noncharacteristic" (12/18) RN. 12/14 malignant nodules occupied >25% of the total teratoma volume (P = 0.09). Features associated with malignancy included the following: age <18 years, an enhancing noncharacteristic RN, teratoma size >12 cm, irregular cystic border, and extralesional extension; these were incorporated into a malignant teratoma score, with a score of 2 or more associated with area under the curve of 0.991 for reviewer 1 and 0.993 for reviewer 2. Peripheral enhancement in a RN was never seen with malignancy (64/123 benign, 0/14 malignant) and would have appropriated downgraded 9/18 overcalled O-RADS 4 benign teratomas. CONCLUSIONS:O-RADS MRI overcalled 15% (18/123) benign teratomas as O-RADS 4 but correctly captured all malignant teratomas. We propose defining a "characteristic" RN as an intravoxel or bulk fat-containing nodule. Observation of a peripheral rim of enhancement in a noncharacteristic RN allowed more accurate prediction of benignity and should be added to the MRI lexicon for improved O-RADS performance.

PURPOSE/OBJECTIVE:The present study aimed to examine the molecular profiles of cytologically indeterminate thyroid nodules stratified by American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) categories and to determine whether certain ultrasonographic features display particular molecular alterations. METHODS:A retrospective review was conducted of cases from January 1, 2016 to April 1, 2018. Cases with in-house ultrasonography, fine-needle aspiration Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) diagnoses, molecular testing, and surgery were included. All cases were diagnosed as TBSRTC indeterminate categories. The ultrasound studies were retrospectively reviewed and assigned TI-RADS scores (TR1-TR5) by board-certified radiologists. The final diagnoses were determined based on the surgical resection pathology. Binary logistic regression analysis was used to study whether demographic characteristics, TI-RADS levels, and TBSRTC diagnoses were associated with ThyroSeq molecular results. RESULTS:Eighty-one cases met the inclusion criteria. RAS mutations were the most common alteration across all TI-RADS categories (TR2 2/2; TR3 10/19, TR4 13/44, and TR5 8/16), and did not stratify with any particular TI-RADS category. Only TR4 and TR5 categories displayed more aggressive mutations such as BRAFV600E and TERT. ThyroSeq results were positively correlated with thyroid malignancy when non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was categorized in the malignant category (odds ratio [OR], 6.859; P<0.01), but not when NIFTP was removed from the malignancy category. Echogenicity scores were found to be negatively correlated with ThyroSeq results in thyroid nodules (OR, 0.162; P<0.01). CONCLUSION/CONCLUSIONS:Higher-risk molecular alterations tended to stratify with the higher TI-RADS categories.

OBJECTIVE. The objective of this article is to assess radiologist concordance in characterizing thyroid nodules using the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS), focusing on the effect of radiologist experience on reader concordance. MATERIALS AND METHODS. Three experienced and three less experienced radiologists assessed 150 thyroid nodules using the TI-RADS lexicon. Percent concordance was determined for various endpoints. RESULTS. Interreader concordance for the five TI-RADS categories was 87.2% for shape, 81.2% for composition, 76.1% for echogenicity, 72.9% for margins, and 69.8% for echogenic foci. Concordance for individual features was 96.3% for rim calcifications, 90.8% for macrocalcifications, 90.1% for spongiform, 83.5% for comet tail artifact, and 77.7% for punctate echogenic foci. Concordance for the TI-RADS level and recommendation for fine-needle aspiration (FNA) were 50.4% and 78.9%, respectively. Concordance was significantly (p < 0.05) higher for less experienced readers in identifying margins (84.3% vs 67.4%), echogenic foci (76.9% vs 69.3%), comet tail artifact (89.6% vs 79.2%), and punctate echogenic foci (85.3% vs 75.5%), and lower for peripheral rim calcifications (95.0% vs 97.8 %), but was not different (p > 0.05) for the remaining categories and features. CONCLUSION. A range of TI-RADS categories, features, and recommendations for FNA had generally moderate interreader agreement among six radiologists. Our results show that concordance for numerous characteristics was significantly higher for the less experienced versus the more experienced readers. These results suggest that less experienced readers relied more on the explicit TI-RADS criteria, whereas the experienced radiologists partially relied on their accumulated experience when forming impressions. However, the overall TI-RADS level and recommendation for FNA were unaffected, supporting the robustness of the TI-RADS lexicon and its continued use in practice.

Women of reproductive age with pelvic pain, vaginal bleeding, and a positive pregnancy test often require evaluation with pelvic ultrasound. In these situations, the primary role of pelvic ultrasound is to differentiate an ectopic pregnancy from either a normal or abnormal intrauterine pregnancy. While an accurately performed and interpreted pelvic ultrasound results in rapid diagnosis and management, numerous diagnostic pitfalls can lead to negative outcomes. Therefore, familiarity with the appropriate laboratory tests, sonographic technique, and imaging features of ectopic pregnancy is essential for all radiologists. We present a review of ectopic pregnancy cases from our institution with attention to common pitfalls and troubleshooting tips for physicians who perform and interpret pelvic ultrasounds. We also present recently published literature to aid in the management of first trimester pregnancy.

OBJECTIVE: The objective of this article is to illustrate the MDCT appearances of several commonly encountered foreign bodies and devices in the female pelvis. CONCLUSION: The presence of a foreign body or device in the female pelvis can be a potential source of confusion to radiologists, particularly to the inexperienced reader. Familiarity with the normal appearances and locations of these devices on MDCT allows their accurate identification and detection of associated complications

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging spectrum of endometriosis