LI-RADS v2018: utilizing ancillary features on gadoxetate-enhanced MRI to modify final LI-RADS category.

PURPOSE: To quantify how often the LI-RADS v2018 category changed when utilizing major features only, when utilizing major and ancillary features, and when utilizing major and ancillary features excluding gadoxetate-specific ancillary features. METHODS: Retrospective analysis of 100 patients age 18 and older at high risk for hepatocellular carcinoma who had an MRI abdomen performed with intravenous contrast gadoxetate between 1/1/2017 and 3/23/2018. Each examination was reviewed by a body fellowship-trained radiologist. LI-RADS category was assigned to the liver observation after review of major features only. Ancillary features were then reviewed and LI-RADS category assigned both including and excluding ancillary features specific to gadoxetate. RESULTS: Utilizing all MRI ancillary features, including those specific to gadoxetate, changed the final LI-RADS category in 56.4% of liver observations, the majority an increase or decrease from LR-3. When not including the ancillary features specific to gadoxetate, the final LI-RADS category changed in 30.9% of observations, the majority increasing from LR-3 to LR-4. CONCLUSION: Utilizing LI-RADS v2018 ancillary features can significantly alter the final LI-RADS category, especially when using gadoxetate-specific ancillary features. Understanding the correct application of ancillary features for the final LI-RADS category helps implement a more consistent category assessment amongst users.

Incidental dedifferentiated mediastinal liposarcoma on F-18-fluciclovine PET/CT.

Fat-containing mediastinal masses, particularly mediastinal liposarcomas, are rare neoplasms that can grow to large sizes before becoming symptomatic and may be incidentally found on radiology examinations. In this case report, a 67-year-old male with a history of prostate cancer status post prostatectomy presented for an F-18-fluciclovine PET/CT for a rising, clinically detectable PSA and indeterminate pelvic lymph nodes seen on multiparametric MRI of the prostate. No local tumor recurrence or metastatic disease from prostate cancer was identified, but the PET/CT demonstrated a mixed soft tissue and fat density prevascular (anterior) mediastinal mass with low-level radiotracer uptake. Following surgical consultation and resection, the final pathology revealed a dedifferentiated mediastinal liposarcoma. The case presented describes the appearance of an uncommon fat-containing mediastinal mass and describes several other fat-containing mediastinal masses that are important for radiologists to recognize in order to formulate accurate differential diagnoses and ensure appropriate further management for patients. Additionally, this case demonstrates that the radiotracer F-18-fluciclovine is not specific for prostate cancer, and its uptake can be seen with other entities such as in this case of sarcomatous malignancy.

High-Resolution Computed Tomography of the Inner Ear: Effect of Otosclerosis on Cochlear Aqueduct Dimensions.

OBJECTIVES: The cochlear aqueduct is a bony duct connecting the scala tympani with the subarachnoid space. Given the pathophysiology of otosclerosis, including bone resorption and new bone deposition, we hypothesize that the cochlear aqueduct in otosclerotic ears is narrowed. METHODS: A retrospective review of patients with otosclerosis who have undergone high-resolution computed tomography (HRCT) of the temporal bone was completed. The control cohort included 20 patients with the diagnosis of noise-induced hearing loss, without the diagnosis of otosclerosis. Uniform measurements of cochlear aqueduct dimensions were performed using the axial plane. RESULTS: The otosclerosis cohort included 25 males and 52 females with mean age of 52.2 ± 17.6 years. The control group included 10 males and 10 females with mean age of 64.0 ± 18.5 years. The mean cochlear aqueduct length, width mid canal, aperture base, aperture widest diameter, and funnel diameter in millimeters were 12.19 ± 1.66, 0.68 ± 0.28, 4.21 ± 1.67, 3.23 ± 1.47, and 2.70 ± 1.05 in the ears with otosclerotic foci and 11.57 ± 1.66, 0.69 ± 0.29, 2.56 ± 1.59, 2.77 ± 1.67, and 2.58 ± 1.03 in control group, respectively. Statistical difference was seen in length of cochlear aqueduct, aperture base, and aperture widest diameters (P = .017, <.001, .007). CONCLUSIONS: The length of the cochlear aqueduct and the funnel width are statistically longer in the otosclerotic population compared to control. The width of the cochlear aqueduct is not statistically different.