Magnetic resonance imaging features predictive of an incomplete response to transarterial chemoembolization in patients with hepatocellular carcinoma: A STROBE-compliant study.

To identify pretreatment magnetic resonance imaging (MRI) features associated with an incomplete response (IR) to transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC).The medical records of 89 patients with HCC who had undergone a first TACE were reviewed retrospectively. The size, visual attenuation in the arterial phase, signal intensity (SI) on T1-, T2-, and diffusion-weighted images, and apparent diffusion coefficient (ADC) values of each lesion were evaluated on pretreatment images. The response to TACE was routinely assessed at 4 weeks post-treatment by 4-phase computed tomography. The HCC patients were classified as complete or incomplete responders based on the arterial-phase enhancement of the target lesion.In multivariate analysis, larger lesion diameter (P = .004, OR = 1.06 per millimeter, 95% CI = 1.02-1.11), faint enhancement on arterial phase (P = .021, OR = 3.24, 95% CI = 1.22-9.14), and non-low SI on T1-weighted images (P = .016, OR = 3.36, 95% CI = 1.29-9.32) were significantly associated with increased odds of an IR to TACE in HCC patients.An iso-to-high T1-weighted SI by pretreatment MRI was an independent predictor of an incomplete response to TACE in patients with HCC, in addition to faint arterial enhancement and lesion size.

Dual-Energy and Iterative Metal Artifact Reduction for Reducing Artifacts Due to Metallic Hardware: A Loosening Hip Phantom Study.

OBJECTIVE. The purpose of this study was to compare the value of iterative metal artifact reduction (IMAR) with that of dual-energy CT (DECT) and filtered back projection (FBP) CT protocols for reducing metal artifacts and for facilitating visualization of the acetabular cortex in a loosening hip phantom model. MATERIALS AND METHODS. CT scans were obtained with conventional FBP and dual-source CT for two types of hip phantom. For the quantitative study, attenuation was measured by placement of ROIs in the phantoms around the metallic hardware. The differences between mean attenuation in each ROI and the actual attenuation were compared among the three CT protocols. For the qualitative study, the visibility of the acetabular cortex in the artificial loosening area of the total hip arthroplasty model and in the joint space of the bipolar hemiarthroplasty model was evaluated by measurement of the obscured cortical angle. RESULTS. In the quantitative study, attenuation differences in the bipolar hemiarthroplasty model were markedly decreased with IMAR and DECT compared with FBP (p = 0.006-0.007). In the total hip replacement model, attenuation differences were significantly lower with IMAR than with FBP (p < 0.001). In the qualitative study, visibility of the acetabular cortex was markedly improved with IMAR compared with DECT and FBP (p < 0.001) for both hip models. CONCLUSION. CT with IMAR can reduce the distortion caused by metal artifacts more effectively than FBP and DECT can while preserving visibility of the acetabular cortex in both bipolar hemiarthroplasty and total hip arthroplasty phantoms.

Papillary Thyroid Carcinoma Arising Within a Follicular Adenoma: A Case Report, Ultrasound Features, and Considerations.

Papillary thyroid carcinoma (PTC) arising within a follicular adenoma is an exceptionally rare histopathological subtype that shows the nuclear features of PTC within a benign-appearing, circumscribed follicular adenoma. Although it is clinically significant because of its malignant nature, its ultrasonographic features have not been described previously. A 26-year-old man presented with a heterogeneous isoechoic solid nodule with a marked hypoechoic solid focus and a low echoic peripheral rim in the right thyroid gland on ultrasonography. On color Doppler images, markedly increased vascularity was seen in the hypoechoic solid component. An ultrasound-guided gun biopsy suggested a follicular neoplasm. In the evaluation of a hemithyroidectomy specimen, thyroid follicles and a thin fibrous capsule were seen, which favored a follicular adenoma with tumor cells in a focal area indicating papillary carcinoma. Here, we report a case of PTC arising within a follicular adenoma and discuss possible considerations in thyroid ultrasonographic examinations.