Objectives: The objective of this study was to compare the diagnostic performance and confidence of conventional, optimized, and ultrashort time to echo (UTE) magnetic resonance (MR) protocols for detection of simulated lumbar spondylolysis in human cadavers. In addition, we sought to demonstrate the feasibility of the UTE technique in subjects with and without spondylolysis. Materials and Methods: Four human lumbar spine specimens with 46 individual pars interarticularis were randomly left intact (n = 26) or received experimental osteotomy (n = 20) using a microsurgical saw to simulate spondylolysis. The specimens were imaged using a computed tomography (CT) scan along with 3 “Tiers” of MR protocols at 3 T: Tier 1, conventional lumbar MR protocol; Tier 2, optimized conventional protocol consisting of a sagittal oblique spoiled gradient recall echo and axial oblique T1 and short tau inversion recovery sequences; and Tier 3, a sagittal UTE MR sequence. Two blinded readers evaluated the images using a 4-point scale (1 = spondylolysis certainly absent, 2 = probably absent, 3 = probably present, 4 = certainly present) at each individual pars. For each imaging protocol, diagnostic performance (sensitivity, specificity, and area under the receiver operating characteristic curve, using the surgical osteotomy as the reference) and confidence were assessed and compared using the McNemar test. Furthermore, 2 human subjects were imaged with the conventional and UTE MR protocols to demonstrate feasibility in vivo. Results: Diagnostic performance was moderate for Tiers 1 and 2, with a moderate sensitivity (0.70 to 0.75) and high (1.00) specificity. In contrast, CT and Tier 3 UTE MR imaging had both high sensitivity (1.00) and specificity (1.00). The sensitivities of CT or Tier 3 were statistically greater than Tier 1 sensitivity (P = 0.041) and neared statistical significance when compared with Tier 2 sensitivity (P = 0.074). Area under the receiver operating characteristic curve was also significantly greater for CT and Tier 3 (each area = 1.00), compared with the areas for Tier 1 (0.89, P = 0.037) or Tier 2 (0.873, P = 0.024). Diagnostic confidences of CT or Tier 3 were much greater than other Tiers: Both Tiers 1 and 2 had a large percentage of uncertain (>60%, P < 0.001) or wrong interpretations (>10%, P < 0.001), unlike CT or Tier 3 (0% uncertain or wrong interpretations). Preliminary in vivo UTE images clearly depicted intact and fractured pars. Conclusions: Our study demonstrated that the detection of pars fractures using a single sagittal UTE MR sequence is superior in performance and confidence to conventional and optimized MR protocols at 3 T, whereas matching those from CT evaluation. Furthermore, we demonstrated the feasibility of in vivo application of the UTE sequence in subjects with and without spondylolysis.

This retrospective study aimed to compare the intra- and inter-observer manual-segmentation variability in the feature reproducibility between two-dimensional (2D) and three-dimensional (3D) magnetic-resonance imaging (MRI)-based radiomic features. The study included patients with lipomatous soft-tissue tumors that were diagnosed with histopathology and underwent MRI scans. Tumor segmentation based on the 2D and 3D MRI images was performed by two observers to assess the intra- and inter-observer variability. In both the 2D and the 3D segmentations, the radiomic features were extracted from the normalized images. Regarding the stability of the features, the intraclass correlation coefficient (ICC) was used to evaluate the intra- and inter-observer segmentation variability. Features with ICC > 0.75 were considered reproducible. The degree of feature robustness was classified as low, moderate, or high. Additionally, we compared the efficacy of 2D and 3D contour-focused segmentation in terms of the effects of the stable feature rate, sensitivity, specificity, and diagnostic accuracy of machine learning on the reproducible features. In total, 93 and 107 features were extracted from the 2D and 3D images, respectively. Only 35 features from the 2D images and 63 features from the 3D images were reproducible. The stable feature rate for the 3D segmentation was more significant than for the 2D segmentation (58.9% vs. 37.6%, p = 0.002). The majority of the features for the 3D segmentation had moderate-to-high robustness, while 40.9% of the features for the 2D segmentation had low robustness. The diagnostic accuracy of the machine-learning model for the 2D segmentation was close to that for the 3D segmentation (88% vs. 90%). In both the 2D and the 3D segmentation, the specificity values were equal to 100%. However, the sensitivity for the 2D segmentation was lower than for the 3D segmentation (75% vs. 83%). For the 2D + 3D radiomic features, the model achieved a diagnostic accuracy of 87% (sensitivity, 100%, and specificity, 80%). Both 2D and 3D MRI-based radiomic features of lipomatous soft-tissue tumors are reproducible. With a higher stable feature rate, 3D contour-focused segmentation should be selected for the feature-extraction process.

Background: Plantar fasciitis is a major cause of heel pain, resulting from repetitive trauma to the plantar fascia and leading to structural changes within the fascia. It has been observed that plantar fascia thickness in plantar fasciitis patients exceeds that of normal individuals. However, the biomechanical properties of the plantar fascia in patients with plantar fasciitis remain unclear. Therefore, this study aimed to compare plantar fascia stiffness between healthy individuals and patients with plantar fasciitis across different areas. Methods: Fifty-eight participants were divided into 2 groups: 29 healthy individuals and 29 individuals with plantar fasciitis. B-mode ultrasonography was used to assess plantar fascia thickness, whereas shear wave elastography was employed to measure plantar fascia stiffness. The study focused on 3 distinct areas: calcaneal insertion, 1-cm distal area, and 2-cm distal area. Additionally, the most painful area reported by patients was marked in the plantar fasciitis group. Results: The findings showed that the plantar fasciitis group exhibited significantly greater plantar fascia stiffness in almost all areas compared to the healthy group ( P < .05). Moreover, the stiffness of the plantar fascia in the most painful area demonstrated the highest value compared with other areas within the plantar fasciitis group ( P < .05). Conclusion: This study suggests structural and mechanical changes in the plantar fascia in patients with plantar fasciitis.

Background: Sarcopenia is a skeletal muscle mass deficiency and a potential prognostic factor for the recurrence of hepatocellular carcinoma (HCC). Objective: To determine whether sarcopenia correlates with the recurrence rate of HCC after curative radiofrequency ablation (RFA) in early and very early HCC. Methods: We retrospectively reviewed 669 HCC patients who underwent their first curative RFA at Siriraj hospital from 2011 to 2020. Fifty-six patients who were diagnosed with HCC by triple-phase CT scan and had complete response on follow-up CT were included. All patients underwent skeletal muscle index (SMI) assessment at level L3 vertebra and sarcopenia was defined by the cut-off values of 52.4 cm2/m2 for men and 38.5 cm2/m2 for women. We compared patients with and without sarcopenia. Time to recurrence was evaluated by the Kaplan-Meier method. Univariate and multivariate Cox regression analysis was performed. Results: Sarcopenia was present in 37 of 56 patients (66.1%). There was no significant difference between groups except body mass index (BMI) (P<0.001) and serum alanine aminotransferase (ALT) (P=0.035). There was a promising result indicating the difference of time to recurrence between each group (P=0.046) and potential association of sarcopenia with HCC recurrence (HR=2.06; P=0.052). The Child-Pugh score and tumor number were independent risk factors for HCC recurrence (HR=2.04; P=0.005 and HR=2.68; P=0.017, respectively). Conclusion: Sarcopenia is a potential prognostic factor for recurrence of HCC in Thai patients who underwent RFA. A larger study is required to properly confirm this association.

Background: Magnetic resonance image (MRI) of the subscapularis tendon plays an important role in preoperative planning. This retrospective study aimed to evaluate the diagnostic value and quantitative measurement of an additional internal rotation sequence in the detection of partial subscapularis tendon tears. Methods: The study included 76 patients who underwent arthroscopy and magnetic resonance (MR) shoulder between January 2018 to December 2019. Three different sets of images were evaluated in each case to determine the diagnostic value in the detection of partial subscapularis tendon tears including Set 1: standard axial fat-suppressed proton density (PD/FS) image and sagittal fat-suppressed T2 weight image (T2W/FS) images, Set 2: standard axial PD/FS and internal rotation PD/FS images, and Set 3: standard axial PD/FS, sagittal T2W/FS and axial internal rotation PD/FS images. Subscapularis tendon tear was diagnosed by arthroscopy and patients with or without tears were grouped. The coracohumoral distance (CHD), coracoglenoid angle (CGA), coracohumeral angle (CHA), CHD difference and CHD ratio were evaluated and compared between groups using univariate and multivariate analysis. The interreader agreement was assessed. The cut-off point for the prediction of subscapularis tears was calculated. Results: Twenty-nine shoulders revealed partial subscapularis tendon tears (29/76, 38.2%). Imaging Set 3 provided the highest sensitivity and accuracy {79–83% [confidence interval (CI): 0.60–0.95], 75–76% (CI: 0.63–0.85)}, compared to image Set 2 [31–58% (CI: 0.15–0.76), 67–68% (CI: 0.55–0.79)] and Set 1 [17–21% (CI: 0.06–0.40], 61–66% (CI: 0.54–0.76)], and a moderate level of interobserver agreement (Kappa =0.55). Axial CHD [odd ratio (OR) =1.48, P=0.044], internal rotate CHD (OR =0.68, P=0.02), CHD difference (OR =2.58, P<0.001), and CHD ratio (OR =1.34, P<0.001) were associated with subscapularis tears. A CHD difference and CHD ratio of more than 0.04 mm and 1.01 achieved a 90% sensitivity and 72% specificity, both. Conclusions: Internal rotation during MRI can increase diagnostic accuracy for subscapularis tendon partial tears. The CHD differences and CHD ratio are useful parameters to indicate subscapularis tears. This technique may improve preoperative management and reduce the consequences of delayed diagnosis and treatment.

Background: Chronic low back pain (LBP) has been associated with intervertebral disc (IVD) degeneration, but its association with abnormal morphology at the discovertebral junction (DVJ) is unclear. The goal of this study was to evaluate the DVJ morphology in asymptomatic (Asx) and symptomatic (Sx) subjects for LBP using ultrashort echo time (UTE) MRI. Methods: We recruited 42 subjects (12 Asx and 32 Sx). Lumbar IVD degeneration was assessed using Pfirrmann grading (1 to 5), while the abnormality of DVJ (0 = normal; 1 = focal; 2 = broad abnormality) was assessed using UTE MRI. The effects of LBP and level on the mean IVD and DVJ grades, the correlation between IVD and DVJ grade, and the effect of LBP and age on the number of abnormal DVJs within a subject were determined. Results: IVD grade was higher in Sx subjects (p = 0.013), varying with disc level (p = 0.033), adjusted for age (p < 0.01). Similarly, DVJ grade was also significantly higher in Sx subjects (p = 0.001), but it did not vary with DVJ level (p = 0.7), adjusted for age (p = 0.5). There was a weak positive (rho = 0.344; p < 0.001) correlation between DVJ and IVD grade. The total number of abnormal DVJs within a subject was higher in Sx subjects (p < 0.001), but not with respect to age (p = 0.6) due to a large spread throughout the age range. Conclusions: These results demonstrate the feasibility of using in vivo UTE MRI of the lumbar spine to evaluate the DVJ and the correlation of DVJ with LBP. This study highlights the need for a better understanding of DVJ pathology and the inclusion of DVJ assessment in routine lumbar MRI.