Thyroid nodule characterization using Spectral Detector Computed Tomography (SDCT) in comparison to ultrasound.

OBJECTIVE: To characterize thyroid nodules seen on Spectral Detector computed tomography (SDCT) in respect to their Thyroid Imaging Reporting and Data System (TI-RADS) category on Ultrasound (US). METHODS: We included patients that underwent US examination for the evaluation of thyroid nodules and contrast-enhanced SDCT examination of the neck/thorax, between the years 2018-2020. The SDCT and US were performed within 6 months of each other. Only patients with a visible thyroid nodule on SDCT were included. Attenuation measurements of the nodules in Hounsfield units (HU) were performed on the conventional CT images, virtual non-contrast (VNC) images and virtual monoenergetic images of 40 keV and 100 keV. The Iodine concentration, spectral slope and enhancement estimation results of the nodules were measured. We compared the spectral results between two groups of nodules, according to the US report: TI-RADS 2-3 and TI-RADS 4-5 groups. RESULTS: Thirty-eight nodules were included in the study, 22 nodules in the TI-RADS 2-3 group and 16 in the TI-RADS 4-5 group. The nodules of the TI-RADS 4-5 group had significantly higher Iodine concentration measurement, 4.6 ± 1.8 mg/ml, compared to 2.3 ± 1.2 mg/ml in the TI-RADS 2-3 group; significantly higher estimated enhancement, 3.9 ± 1.5, compared to 2.2 ± 0.7; and significantly higher calculated spectral slope, 5.6 ± 2.2 compared to 2.9 ± 1.5 (p < 0.001). CONCLUSION: Spectral results of SDCT may assist in differentiating intermediate-high risk (TI-RADS 4-5) from low risk (TI-RADS 2-3) thyroid nodules. ADVANCES IN KNOWLEDGE: SDCT offers additional information for the characterization of thyroid nodules.

Increased Renal Echogenicity in Children With Appendicitis.

OBJECTIVES: Ultrasound (US) is an important modality for the detection of acute appendicitis in children but has limited sensitivity and specificity. Therefore, additional US findings may contribute to the diagnosis. In our experience, children with acute appendicitis often have increased renal cortical echogenicity on US imaging. The purpose of this study was to examine the association of increased renal cortical echogenicity with appendicitis. METHODS: This study included 240 consecutive pediatric patients with no renal or liver disease who underwent US examinations for suspected appendicitis between February 2014 and January 2016. Ultrasound images of the liver and right kidney were retrospectively reviewed, and the echogenicity of the renal cortex was classified as less than the liver, equal to the liver, or greater than the liver. RESULTS: The renal cortex was abnormally hyperechoic in 38 (50%) of all of the patients who had appendicitis according to US (P < .001) and in 47% of patients who underwent appendectomy (P = .002). Overall, 36% of patients with increased renal cortical echogenicity had a diagnosis of appendicitis. After correction for variables, patients with renal hyperechogenicity had a 2.5 times chance of appendicitis (odds ratio, 2.5). CONCLUSIONS: There is a statistically significant association between increased renal cortical echogenicity and appendicitis. In the absence of hepatic or renal disease, this finding may increase the accuracy of the US diagnosis of appendicitis. Increased renal cortical echogenicity may be added to the list of US findings accompanying acute appendicitis in children.