The Prospective Natural History Study of Patients with Intractable Venous Malformation and Klippel-Trenaunay Syndrome to Guide Designing a Proof-of-Concept Clinical Trial for Novel Therapeutic Intervention.

Background: The natural history of venous malformation (VM) and Klippel-Trenaunay Syndrome (KTS) has not been quantitatively studied. To obtain benchmarks to guide designing clinical trials to assess safety and efficacy of novel drug candidates, the clinical course of the patients was followed for 6 months. Methods and Results: This is a multicenter prospective observational study evaluating the change rate in lesion volume from baseline with magnetic resonance images, as the primary endpoint. In addition, disease severities, performance status (PS), pain visual analog scale (VAS) score, quality of life (QoL), infections, and coagulation markers were also evaluated. Thirty-four patients (VM = 17, KTS = 17, 1-53 of age; median 15.9 years) with measurable lesion volume were analyzed. There was no statistically significant difference in the lesion volume between baseline and day 180, and the mean change rate (standard deviation) was 1.06 (0.28). There were no baseline characteristics that affected the change in lesion volume over 6 months. However, there were patients who showed more than 20% volume change and it was suggested that the lesion volume was largely impacted by local infection. There were no statistically significant changes in pain VAS score, severity, PS, QoL score, D-dimer, and platelet count over 6 months within all patients analyzed. Conclusion: The results showed the representative natural course of VM and KTS for a 6-month period with objective change of lesion volume and other factors, suggesting that it is scientifically reasonable to conduct a Phase 2 proof-of-concept study without a placebo arm, using the results of this study as the control. Clinical Trial Registration: NCT04285723, NCT04589650.

Longitudinal MR quantification of the fat fraction within the supraspinatus and infraspinatus muscles in patients with shoulder pain.

RATIONALE AND OBJECTIVES: Knowing the natural history of fatty degeneration of rotator cuff muscles is important for estimating the risk and rate of progression to cuff tear arthropathy (CTA). The purpose of this study was to investigate the changes in rotator cuff muscle fatty degeneration over time quantitatively in patients treated conservatively for shoulder pain. MATERIALS AND METHODS: Thirty patients with a baseline and follow-up shoulder MRI, including a 2-point Dixon sequence, which were performed at least 1 year apart, were included. We classified patients into 3 groups: "full-thickness tear" (n = 7), "partial-thickness tear" (n = 13), and "no-tear" (n = 10) groups. The fat fraction in the supra- and infraspinatus muscles, and the rate of change in the fat fraction (ΔFfr) were calculated using the formula "fat fraction of follow-up MRI/fat fraction of initial MRI." We investigated the difference in ΔFfr among the 3 groups and the degree of progression to CTA. RESULTS: Statistically significant differences in ΔFfr within the supraspinatus and infraspinatus muscles were found among full-thickness, partial-thickness, and no-tear groups (2.54 vs 1.02 vs 0.75, p < 0.001 and 1.96 vs 1.07 vs 0.73, p = 0.021, respectively). Overall, 71.4% of the full-thickness tear group showed progression of CTA, and 28.6% of the full-thickness tear group needed reverse shoulder arthroplasty within an average follow-up period of 34 months. CONCLUSIONS: MR quantification, together with the knowledge of change in fatty degeneration over time, may be useful for the management of patients with shoulder pain.

Review of Quantitative Knee Articular Cartilage MR Imaging.

Osteoarthritis (OA) is one of the most prevalent disorders in today's society, resulting in significant socio-economic costs and morbidity. MRI is widely used as a non-invasive imaging tool for OA of the knee. However, conventional knee MRI has limitations to detect subtle early cartilage degeneration before morphological changes are visually apparent. Novel MRI pulse sequences for cartilage assessment have recently received increased attention due to newly developed compositional MRI techniques, including: T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), sodium MRI, diffusion-weighted imaging (DWI)/ diffusion tensor imaging (DTI), ultrashort TE (uTE), and glycosaminoglycan specific chemical exchange saturation transfer (gagCEST) imaging. In this article, we will first review these quantitative assessments. Then, we will discuss the variations of quantitative values of knee articular cartilage with cartilage layer (depth)- and angle (regional)-dependent approaches. Multiple MRI sequence techniques can discern qualitative differences in knee cartilage. Normal articular hyaline cartilage has a zonal variation in T2 relaxation times with increasing T2 values from the subchondral bone to the articular surface. T1rho values were also higher in the superficial layer than in the deep layer in most locations in the medial and lateral femoral condyles, including the weight-bearing portion. Magic angle effect on T2 mapping is clearly observed in the both medial and lateral femoral condyles, especially within the deep layers. One of the limitations for clinical use of these compositional assessments is a long scan time. Recent new approaches with compressed sensing (CS) and MR fingerprinting (MRF) have potential to provide accurate and fast quantitative cartilage assessments.

Quantitative MRI Analysis of the Talocrural and Talonavicular Joints in Ballet Dancers.

The ankles of ballet dancers are routinely under heavy loading that may lead to osteoarthritic changes. It would be clinically useful to identify such pathology as early as possible in a dancer's career. Therefore, the purpose of this study was to compare quantitative measurements in magnetic resonance (MR) images of the talocrural and talonavicular joints in ballet dancers and healthy non-dancers for use in formulating prediction of chronic injury and degenerative joint disease in these locations. Quantitative measurements in MR images of the talocrural and talonavicular joints were compared in 10 female ballet dancers, 10 healthy female non-dancers, and nine male ballet dancers. Fat-suppressed density-weighted proton, T1rho, and T2 mapping images were acquired with a 3.0 T MR scanner. Medial and lateral subchondral bone distance between the tibia and talus (MSBD and LSBD), axial navicular-talus axis angle (ANT angle), sagittal talar neck angle against the posterior talocalcaneal joint (TN angle), and curvature of navicular surface at the talonavicular joint were measured on sagittal images. The medial subchondral bone distance was found to be significantly larger in female dancers than female non-dancers (4.05 mm vs. 2.75 mm, p < 0.05), whereas there were no significant differences in LSBD (2.63 mm vs. 2.63 mm, p = 0.87). Axial navicular talus angles in female dancers were significantly larger than those in female non-dancers (38.9° vs. 24.3°, p < 0.05). There was a tendency for the TN angle to be smaller and navicular curvature (NC) to be larger in female dancers compared to female non-dancers, though the differences were not significant (TN angle: 16.6° vs. 22.3°, p = 0.09, and NC: 0.186 vs. 0.165, p = 0.28). There were no significant differences in T1rho or T2 values of talonavicular joint cartilage. These results show that the bony anatomy of dancers' ankles may adapt to the stresses placed on them by ballet.

There are no three physiological narrowings in the upper urinary tract: a new concept of the retroperitoneal anatomy around the ureter.

The widely held dogma of three physiological narrowings in the upper urinary tract has proven incorrect by recent several studies using computed tomography images. There are only two common obstruction sites: the upper ureter and the ureterovesical junction. The second narrowing, where the ureter crosses the iliac vessels, cannot be regarded anymore as a common obstruction site. The mechanism by which stones lodge in the upper ureter is explained anatomically by the change in ureteral mobility and compliance at the level where the ureter exits the perirenal space. This level can be identified radiologically as the point where the ureter crosses under the ipsilateral gonadal veins, termed the "crossing point". Kinking of the upper ureter is another manifestation of this anatomical phenomenon, visible in radiological images. It is caused by loosening of the ureter at or above the crossing point (within the perirenal space), corresponding with renal descent such as during the inspiratory phase. This new anatomical discovery in the retroperitoneum will not only bring about a paradigm shift in terms of the physiological narrowings in the upper urinary tract, but may also lead to the development of new surgical concepts and approaches in the area.

Prediction of Stress Distribution Applied to the Triangular Fibrocartilage Complex: A Finite Element Analysis.

Purpose: The triangular fibrocartilage complex (TFCC) is an important tissue stabilizer for the distal radioulnar joint, but stress distribution on the TFCC is not clear. The purpose of this study was to report the stress distribution of the TFCC using finite element analysis (FEA). Methods: Pathological specimens of the wrist joint from an 80-year-old man were imported into a finite element analysis software package, and regions of interest including bone, soft tissue, and TFCC were extracted to create a 3-dimensional model. The material properties were obtained from previous research using cadaver specimens. To allow large deformations, we used hyperelastic elements to model the TFCC and soft tissue. Bone was defined as a uniform tissue that did not break. With the carpals and radius constrained, the rotation axis was set at the center of the ulnar head and a force was applied to move the ulnar head in pronation and supination. Under these boundary conditions, the behavior of the TFCC was extracted as a moving image. The average value of the maximum principal stress for each component of the TFCC was extracted and graphed. Results: In the supinated position, the maximum principal stress was found on the palmar side of the TFCC (eg, on the tension side). In pronation, the maximum principal stress was found on the dorsal side. Conclusions: This study clearly showed the 3-dimensional structure of the TFCC and analyzed its stress distribution under load. In supination, mean values of the maximum principal stress were greater on the palmar fibers than the dorsal fibers. In pronation, mean maximum principal stress was greater on the dorsal fibers than the palmar fibers. Clinical relevance: Knowing the distribution of stresses in the TFCC is an important factor in developing treatment strategies for a pathologic TFCC.

Comparison of visibility of ulnar sided triangular fibrocartilage complex (TFCC) ligaments between isotropic three-dimensional and two-dimensional high-resolution FSE MR images.

OBJECTIVES: Assessment of the ulnar attachment of the triangular fibrocartilage complex (TFCC) in a neutral forearm position remains challenging. Our study aims to evaluate the visibility of ulnar sided TFCC on 3 T MRI and compare isotropic 3D FSE sequences utilizing multiplanar reformation (MPR) with standard high-resolution 2D FSE sequences. METHODS: Ninety-nine MRI wrist studies in patients with wrist pain were retrospectively analyzed. Patients were scanned with a neutral forearm position and reviewed with isotropic 3D coronal FSE proton density-weighted images (PDWI) and 2D coronal FSE PDWI. MPR was used for 3D assessment. Visibility of the dorsal radioulnar ligament (DRUL), triangular ligament (TL), and volar radioulnar ligament (VRUL) was assessed by three raters utilizing a five-point grading scale. Grades were compared between 2D and 3D sequences. Intrarater and interrater reliability for the delineation of anatomic structures was measured by Spearman's rank correlation coefficient, Cohen's kappa, and percentage of exact agreement/agreement within a range of ±1 score point. RESULTS: Visibility grades in 3D were statistically significantly higher than those in 2D in all ligaments by all raters (p < 0.01). In Spearman's rank correlation coefficient and Cohen's kappa analysis, interrater correlations and agreements are variable but tended to be higher on 3D than on 2D. Both 2D and 3D sequences showed high intrarater exact agreement in all ligaments (80-91 % on 2D and 88-95 % on 3D). All exact interrater agreements on 3D were acceptable for TL (83-93 %) and acceptable to close to acceptable for VRUL (72-96 %). CONCLUSION: The utilization of isotopic 3D imaging combined with MPR function significantly improves visibility of ulnar attachment of the TFCC.

Anatomical relationship between the morphology of the styloid process of the ulna and the attachment of the radioulnar ligaments.

The radioulnar ligaments are the major stabilizers of the distal radioulnar joint under dynamic loading; however, anatomical detail regarding their attachment on the middle and distal thirds of the styloid process of the ulna remains unclear. Because previous anatomical studies included only old cadavers, their anatomical findings might not reflect the morphological features of younger and healthy specimens. This study investigated the anatomical features of the distal ulna, particularly the styloid process, to determine the attachment of the radioulnar ligaments to the styloid process and verified their direction and attachment to the styloid process in younger and healthy donors using magnetic resonance imaging (MRI). We investigated the morphological features of the distal ulna of 12 cadaveric wrists using micro-computed tomography (micro-CT). We also visualized and measured the distribution of the cortical bone thickness. We histologically analyzed three specimens in the axial plane and macroscopically analyzed seven specimens to examine the attachment of the radioulnar ligaments to the styloid process. In addition, we evaluated five wrists from living volunteers using 3.0 Tesla MRI. The distal ulna has a ridge on the dorsoradial aspect of the styloid process that corresponds to the attachment of the radioulnar ligaments. Micro-CT images after data processing revealed that the cortical thickness of the dorsoradial quadrant was thicker than that of the other quadrant at the proximal slice of the styloid process (p < 0.01), and that of the dorsoulnar (p = 0.021) and ulnopalmar (p < 0.01) quadrants at the middle slice. Histological analyses showed that the radioulnar ligaments were attached to the middle and distal thirds of the styloid process via chondral-apophyseal entheses. The direction of the fiber was dorsal in the middle third of the styloid process and changed to palmar in the distal third of the styloid process. The direction and attachment of the radioulnar ligaments on the styloid process were confirmed using MRI for younger and healthy participants. The radioulnar ligaments were attached to the dorsoradial ridge of the styloid process, which was confirmed by cortical bone thickening, histology at the attachment sites, and in vivo MR imaging. The directions of the radioulnar ligaments sterically intersected, which would satisfy both slipping stability and rotational mobility. These anatomical findings may provide the basis for biomechanical consideration of distal radioulnar joint stabilization.

T1rho and T2 mapping of ankle cartilage of female and male ballet dancers.

BACKGROUND: Since ballet dancers begin their training before skeletal maturity, accurate and non-invasive identification of cartilage diseases is clinically important. Angle-dependent analysis of T1rho and T2 sequences can be useful for quantification of the composition of cartilage. PURPOSE: To investigate the angle-dependent T1rho and T2 profiles of ankle cartilage in non-dancers and dancers. MATERIAL AND METHODS: Ten female non-dancers, ten female dancers, and 9 male dancers were evaluated using T1rho and T2 mapping sequences. Manual segmentation of talar and tibial cartilage on these images was performed by two radiologists. Inter- and intra-rater reliabilities were calculated using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Mean thickness and volume of cartilage were estimated. Angle-dependent relaxation time profiles of talar and tibial cartilage were created. RESULTS: ICCs of the number of segmented pixels were poor to excellent. Bland-Altman plots indicated that differences were associated with segment sizes. Segmented cartilage on T1rho demonstrated larger thickness and volume than those on T2 in all populations. Male dancers showed larger cartilage thickness and volume than female dancers and non-dancers. Each cartilage demonstrated angular-dependent T1rho and T2 profiles. Minimal T1rho and T2 values were observed at approximately 180°-200°; higher values were seen at the angle closer to the magic angle. Minimal T2 value of talar cartilage of dancers was larger than that of non-dancers. CONCLUSION: In this small cohort study, regional and sex variations of ankle cartilage T1rho and T2 values in dancers and non-dancers were demonstrated using an angle-dependent approach.

Comparison Between Isotropic 3-Dimensional Fat-Suppressed T2-Weighted Fast Spin Echo (FSE) and Conventional 2-Dimensional Fat-Suppressed Proton-Weighted FSE Shoulder Magnetic Resonance Imaging at 3-T in Patients With Shoulder Pain.

OBJECTIVE: The aims of this study were to compare isotropic 3-dimensional fat-suppressed T2-weighted fast spin echo (FSE) imaging (T2FS) with 2-dimensional fat-suppressed proton-density-weighted FSE imaging (2D-PDFS) and evaluate feasibility of isotropic 3-dimensional FSE shoulder imaging at 3-T magnetic resonance imaging (MRI). METHODS: Seventy-eight patients who underwent shoulder MRI were evaluated. Three-dimensional T2FS and 2D-PDFS were qualitatively graded for delineation of anatomic structures. In quantitative analysis, mean relative signal intensity and relative signal contrast between each structure of the shoulder were compared. RESULTS: Three-dimensional T2FS showed significantly higher scores for rotator cuff (P = 0.020), lower scores for bone (P < 0.001), and higher relative contrast of rotator cuff to fluid (P < 0.001) and labrum to fluid (P < 0.001) in comparison with 2D-PDFS. No significant difference in relative signal intensity of the rotator cuff, labrum, joint fluid, cartilage, and bone marrow was demonstrated. CONCLUSIONS: Isotropic 3-dimensional FSE MRI has similar image quality and diagnostic performance to conventional 2-dimensional sequence in evaluation of the rotator cuff.

Extrahepatic Collateral Artery Extravasation in Patients with Ruptured Hepatocellular Carcinoma.

This report describes 3 patients with previously untreated hepatic tumors who underwent embolization for the treatment of extravasation from extrahepatic arteries. Although development of extrahepatic collateral blood supply is well known, its importance in the presentation of rupture of liver tumors may be underrecognized. Findings that suggest bleeding from extrahepatic arteries include a discrepancy in the pattern of extravasation on computed tomography vs hepatic angiography and a lack of stabilization of vital signs after embolization of hepatic arteries. To achieve successful hemostasis in embolization, the potential involvement of such extrahepatic arteries should be accurately recognized, suggestive imaging findings considered, and the occult vessels selected and embolized.

Mucin-poor and aggressive mucinous tubular and spindle cell carcinoma of the kidney: Two case reports.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare renal epithelial neoplasm. Although MTSCC is considered to be a low-grade and indolent neoplasm, aggressive cases have been recently reported. The present study discussed two additional cases of high-grade MTSCC causing multiple distant metastases with a fatal course. In case 1, a 71-year-old patient presented with hematuria and pyuria. Computed tomography (CT) scan of the right kidney revealed a mass lesion, for which partial nephrectomy was performed. However, a follow-up CT imaging revealed distant metastases in the liver, the paraaortic lymph nodes and the bone. Despite molecular targeted therapy and irradiation, the patient succumbed due to tumor progression. In case 2, a 64-year-old patient presented with an incidentally identified mass lesion in the right kidney. A laparoscopic nephrectomy was performed, and a follow-up CT imaging revealed metastases in the skin and lungs. The cytology of pleural effusion revealed pleuritis carcinomatosa. Histologically, both cases were diagnosed as mucin-poor MTSCC with high-grade transformation, which comprised uniform tumor cells primarily forming slender tubules. The tumors contained low- and high-grade regions. In addition, venous invasion and necrosis were observed. The tumor cells also demonstrated increased Ki-67 labeling indices and cellular tumor antigen p53 (p53) nuclear accumulation. High-grade transformation, large tumor size, necrosis, venous invasion, high Ki-67 labeling index and p53 nuclear accumulation are generally predictive findings for aggressive behavior of malignant tumors. In the current report, it was emphasized that MTSCC possesses a wide spectrum of clinicopathological features. Thus, careful postoperative investigation is required for MTSCC with high-grade elements due to its aggressive nature.

Advanced Imaging Techniques of the Wrist.

OBJECTIVE: This article covers the technical aspects and clinical applications of recent advancements in wrist MRI techniques, including T2 and T1rho mapping, compressed sensing, and isotropic 3D imaging using driven equilibrium sequences, variable-flip-angle refocusing pulse sequences, and parallel imaging. The clinical applications of these techniques include the quantitative analysis of cartilage and triangular fibrocartilaginous complex (TFCC) degeneration, faster scanning times, and improved resolution of complex wrist anatomy, allowing differentiation of degenerative from traumatic TFCC tears and improved morphologic evaluation of chondromalacia. CONCLUSION: MRI of the wrist and of the musculoskeletal system has had multiple novel and exciting advancements in recent years. Several of these advancements, such as parallel imaging, are already in clinical use, and others will be entering the clinical realm in the near future. An understanding of these techniques allows one to use their advantages to greatest effect.

The Peak Site of Stone Distribution in the Upper Ureter is Unlikely the Ureteropelvic Junction: Computed Tomography Analysis of Stone Lodging Site With Respect to a Newly Identified Area of Constriction.

OBJECTIVE: To investigate the relationship between the upper urinary stone distribution and the "crossing point," an area of relative fixation within the upper ureter at approximately the level where the ureter crosses the gonadal vein. MATERIALS AND METHODS: We reviewed 298 consecutive patients presenting with acute renal colic, identified upper ureteral stones in computed tomography. For stones located at the "renal pelvis and upper ureter," we measured the vertebral level of each renal pelvis, crossing point, and stone. The distance between the crossing point and the stones (designated as positive if the stone was located above it) and the distance between the renal pelvis and the crossing point were measured. RESULTS: The average stone size at the "renal pelvis and upper ureter" was 6.0 ± 3.2 mm, at "middle ureter" 5.2 ± 1.9 mm, and at "lower ureter" 3.7 ± 1.8 mm. Lower location was significantly correlated with smaller size (P <.001). The level of the crossing point and stone location were significantly lower on the right (P = .019, P = .033, respectively), whereas the vertebral level of the renal pelvis was not significantly different on both sides (P = .225). The mean distance between the crossing point and the stones was -5.6 ± 18.4 mm (median: 0 mm) on the right and -4.7 ± 19.3 mm (median: 0 mm) on the left. The mean distance between the renal pelvis and the stones was significantly longer on the right (57.2 ± 18.5 mm and 48.2 ± 19.1 mm) (P = .038). CONCLUSION: The crossing point is the peak site of stone distribution in the upper ureter and likely different from the traditionally identified obstruction site at the ureteropelvic junction.

Reliability of MR Quantification of Rotator Cuff Muscle Fatty Degeneration Using a 2-point Dixon Technique in Comparison with the Goutallier Classification: Validation Study by Multiple Readers.

RATIONALE AND OBJECTIVES: Presurgical assessment of fatty degeneration is important in the management of patients with rotator cuff tears. The Goutallier classification is widely accepted as a qualitative scoring system, although it is highly observer-dependent and has poor reproducibility. The objective of this study was to quantify fatty degeneration of the supraspinatus muscle using a 2-point Dixon technique in patients with rotator cuff tears by multiple readers, and to evaluate the reproducibility compared to Goutallier classification. MATERIALS AND METHODS: Two hundred patients with rotator cuff tears who underwent magnetic resonance imaging (MRI), including 2-point Dixon sequence at 3.0-T, were selected retrospectively. Qualitative and quantitative analyses of fatty degeneration were performed by two radiologists and three orthopedic surgeons independently. The fat quantification was performed by measuring signal intensity values of in phase (S(In)) and fat image (S(Fat)), and calculating fat fraction as S(Fat)/S(In). The reproducibility of MR quantification was analyzed by the intra- and interclass correlation coefficients and Bland-Altman plots. RESULTS: The interobserver agreement of the Goutallier classification among five readers was moderate (k = 0.51), whereas the interclass correlation coefficient regarding fat fraction value quantified in 2-point Dixon sequence was excellent (0.893). The mean differences in fat fraction values from the individual segmentation results were from -0.072 to 0.081. Proposed fat fraction grading and Goutallier grading showed similar frequency and distribution in severity of rotator cuff tears. CONCLUSIONS: Fat quantification in the rotator cuff muscles using a 2-point Dixon technique at 3.0-T MRI is highly reproducible and clinically feasible in comparison to the qualitative evaluation using Goutallier classification.

Predicting Retear after Repair of Full-Thickness Rotator Cuff Tear: Two-Point Dixon MR Imaging Quantification of Fatty Muscle Degeneration-Initial Experience with 1-year Follow-up.

Purpose To determine the degree of preoperative fatty degeneration within muscles, postoperative longitudinal changes in fatty degeneration, and differences in fatty degeneration between patients with full-thickness supraspinatus tears who do and those who do not experience a retear after surgery. Materials and Methods This prospective study had institutional review board approval and was conducted in accordance with the Committee for Human Research. Informed consent was obtained. Fifty patients with full-thickness supraspinatus tears (18 men, 32 women; mean age, 67.0 years ± 8.0; age range, 41-91 years) were recruited. The degrees of preoperative and postoperative fatty degeneration were quantified by using a two-point Dixon magnetic resonance (MR) imaging sequence; two radiologists measured the mean signal intensity on in-phase [S(In)] and fat [S(Fat)] images. Estimates of fatty degeneration were calculated with "fat fraction" values by using the formula S(Fat)/S(In) within the supraspinatus, infraspinatus, and subscapularis muscles at baseline preoperative and at postoperative 1-year follow-up MR imaging. Preoperative fat fractions in the failed-repair group and the intact-repair group were compared by using the Mann-Whitney U test. Results The preoperative fat fractions in the supraspinatus muscle were significantly higher in the failed-repair group than in the intact-repair group (37.0% vs 19.5%, P < .001). Fatty degeneration of the supraspinatus muscle tended to progress at 1 year postoperatively in only the failed-repair group. Conclusion MR imaging quantification of preoperative fat fractions by using a two-point Dixon sequence within the rotator cuff muscles may be a viable method for predicting postoperative retear. (©) RSNA, 2016.

Quantification of Fatty Degeneration Within the Supraspinatus Muscle by Using a 2-Point Dixon Method on 3-T MRI.

OBJECTIVE: The objective of this study was to quantify fatty degeneration of the supraspinatus muscle by using a 2-point Dixon technique on 3-T MRI and to evaluate the correlation of muscular atrophy and fat fraction values among different severities of rotator cuff tears across differing ages and sexes. SUBJECTS AND METHODS: Patients with shoulder pain (n = 359) were evaluated by shoulder MRI on a 3-T unit, including a 2-point Dixon sequence for quantification of muscle atrophy and fatty degeneration within the supraspinatus muscle. Two board-certified musculoskeletal radiologists evaluated the degree of rotator cuff tears in three groups: full-thickness tear (n = 63), partial tear (n = 54), and no tear (n = 242). In quantitative analysis, we measured signal intensity values of in-phase images (SIn) and fat images (SFat) within the supraspinatus muscle, and the fat fraction was calculated as SFat/SIn. The Thomazeau occupation ratio was used as a quantitative index of muscular atrophy. Fat fraction and muscle atrophy were evaluated among these groups. RESULTS: Fat fraction values were changed with the degree of rotator cuff tears and were (mean ± SD) 0.258 ± 0.123 among patients with full-thickness tears, 0.166 ± 0.067 among patients with partial tears, and 0.128 ± 0.061 among patients with no tears, with statistically significant differences (p < 0.001). The values were higher in female than in male patients in all groups. The Pearson correlation coefficient was 0.348 between age and fat fraction value, and 0.664 between muscular atrophy rate and fat fraction value. CONCLUSION: An increase in supraspinatus fatty degeneration was statistically significantly correlated with severity of supraspinatus tears and moderately correlated with muscular atrophy. Fatty degeneration tends to progress more rapidly than muscular atrophy in female patients, with statistically significant sex differences.