Quantitative MRI of visually intact rotator cuff muscles by multiecho Dixon-based fat quantification and diffusion tensor imaging.

BACKGROUND: Quantitative MRI allows assessment of shoulder rotator cuff (RC) muscles by Dixon MR sequences with calculation of fractional fat content (FF%) maps and diffusion tensor imaging (DTI) including tractography. PURPOSE: To compare FF% and DTI derived parameters among visually intact RC muscles, to compare 2D with 3D DTI measurements and to establish normative values. STUDY TYPE: Prospective. SUBJECTS: Forty patients aged >18 years undergoing shoulder MR arthrography were included. FIELD STRENGTH/SEQUENCE: MR arthrography of the shoulder including 3D multiecho Dixon and 3D echo-planar DTI sequences (15 gradient encoding directions, b-value 600 s/mm2 ) was performed at 3.0T. ASSESSMENT: Muscles affected by RC tears or fatty infiltration of Goutallier grade ≥1 were excluded. Two independent radiologists measured FF%, apparent diffusion coefficient (ADC), and fractional anisotropy (FA) by region-of-interest (ROI) placements at the Y-position of the scapula and 3D tractography of each muscle with qualitative evaluation was performed. STATISTICAL TESTS: Intraclass correlation coefficients (ICCs) and Cohen's kappa were used for interreader agreement and Pearson correlation coefficient to correlate quantitative measures with each other and age, independent-samples t-test, one-way analysis of variance (ANOVA), and Kruskal-Wallis test were performed to investigate differences between genders and muscles. RESULTS: Qualitative and quantitative measurements showed moderate (κ = 0.41-0.56) to almost perfect (ICC = 0.75-0.99) agreement. There were weak but significant positive correlations of FF% with age (r = 0.273, P < 0.05) and FA-2D (r = 0.319-0.383, P < 0.05). Significant differences were found among RC muscles for ADC, radial diffusivity (RD), and tract homogeneity (all P < 0.05) but not between genders (all P ≥ 0.05). High correlations of 2D with 3D measurements for ADC (r = 0.639, P < 0.001) and FA (r = 0.628, P < 0.001) were seen. DATA CONCLUSION: Quantitative MRI with estimation of FF% and DTI parameters shows significant age-associated changes and differences among visually intact RC muscles. High reproducibility and correlations of 2D with 3D DTI measurements can be expected. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:109-117.

Whole-body adipose tissue and lean muscle volumes and their distribution across gender and age: MR-derived normative values in a normal-weight Swiss population.

PURPOSE: To determine age- and gender-dependent whole-body adipose tissue and muscle volumes in healthy Swiss volunteers in Dixon MRI in comparison with anthropometric and bioelectrical impedance (BIA) measurements. METHODS: Fat-water-separated whole-body 3 Tesla MRI of 80 healthy volunteers (ages 20 to 62 years) with a body mass index (BMI) of 17.5 to 26.2 kg/m2 (10 men, 10 women per decade). Age and gender-dependent volumes of total adipose tissue (TAT), visceral adipose tissue (VAT), total abdominal subcutaneous adipose tissue (ASAT) and total abdominal adipose tissue (TAAT), and the total lean muscle tissue (TLMT) normalized for body height were determined by semi-automatic segmentation, and correlated with anthropometric and BIA measurements as well as lifestyle parameters. RESULTS: The TAT, ASAT, VAT, and TLMT indexes (TATi, ASATi, VATi, and TLMTi, respectively) (L/m2 ± standard deviation) for women/men were 6.4 ± 1.8/5.3 ± 1.7, 1.6 ± 0.7/1.2 ± 0.5, 0.4 ± 0.2/0.8 ± 0.5, and 5.6 ± 0.6/7.1 ± 0.7, respectively. The TATi correlated strongly with ASATi (r > 0.93), VATi, BMI and BIA (r > 0.70), and TAATi (r > 0.96), and weak with TLMTi for both genders (r > -0.34). The VAT was the only parameter showing an age dependency (r > 0.32). The BMI and BIA showed strong correlation with all MR-derived adipose tissue volumes. The TAT mass was estimated significantly lower from BIA than from MRI (both genders P < .001; mean bias -5 kg). CONCLUSIONS: The reported gender-specific MRI-based adipose tissue and muscle volumes might serve as normative values. The estimation of adipose tissue volumes was significantly lower from anthropometric and BIA measurements than from MRI. Magn Reson Med 79:449-458, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Shoulder muscle volume and fat content in healthy adult volunteers: quantification with DIXON MRI to determine the influence of demographics and handedness.

OBJECTIVE: We aimed to provide mean values for fat-fraction and volume for full-length bilateral rotator cuff and deltoid muscles in asymptomatic adults selected on the basis of their good musculoskeletal and systemic health, and to understand the influence of gender, age, and arm dominance. MATERIALS AND METHODS: Seventy-six volunteers aged 20 to 60 years who were screened for normal BMI and high general health were included in the study. MRI was performed at 3 Tesla using three-point DIXON sequences. Volume and fat-signal fraction of the rotator cuff muscles and the deltoid muscle were determined with semi-automated segmentation of entire muscle lengths. Differences according to age, gender, and handedness per muscle were evaluated. RESULTS: Fat-signal fractions were comparable between genders (mean ± 2 SD, 95% CI, women 7.0 ± 3.0; 6.8-7.2%, men 6.8 ± 2.7; 6.7-7.0%) but did not show convincing changes with age. Higher shoulder muscle volume and lower fat-signal fraction in the dominant arm were shown for teres minor and deltoid (p < 0.01) with similar trends shown for the other rotator cuff muscles. CONCLUSIONS: Bilateral fat-signal fractions and volumes based on entire length shoulder muscles in asymptomatic 20-60 year old adults may provide reference for clinicians. Differences shown according to arm dominance should be considered and may rationalize the need for bilateral imaging in determining appropriate management.

Association between traumatic bone marrow abnormalities of the knee, the trauma mechanism and associated soft-tissue knee injuries.

OBJECTIVES: To determine the association between traumatic bone marrow abnormalities, the knee injury mechanism, and associated soft tissue injuries in a larger cohort than those in the published literature. METHOD: Retrospective study including 220 patients with traumatic knee injuries. Knee MRIs were evaluated for trauma mechanism, soft tissue injury, and the location of bone marrow abnormalities. The locations of the abnormalities were correlated with trauma mechanisms and soft tissue injuries using the chi-square test with Bonferroni correction. RESULTS: One hundred and forty-four valgus injuries, 39 pivot shift injuries, 25 lateral patellar dislocations, 8 hyperextensions, and 4 dashboard injuries were included. Valgus and pivot shift injuries showed traumatic bone marrow abnormalities in the posterolateral regions of the tibia. Abnormalities after patellar dislocation were found in the anterolateral and centrolateral femur and patella. Hyperextension injuries were associated with abnormalities in almost all regions, and dashboard injuries were associated with changes in the anterior regions of the tibia and femur. CONCLUSIONS: Our study provides evidence of associations between traumatic bone marrow abnormality patterns and different trauma mechanisms in acute knee injury, and reveals some overlap, especially of the two most common trauma mechanisms (valgus and pivot shift), in a large patient cohort. KEY POINTS: • Specific bone marrow oedema patterns after knee trauma were confirmed. • New associations between bone marrow oedema patterns and knee trauma were shown. • Bone marrow oedema patterns help in identifying associated soft tissue injuries.

C-arm flat-panel CT arthrography of the shoulder: Radiation dose considerations and preliminary data on diagnostic performance.

OBJECTIVES: To investigate radiation dose and diagnostic performance of C-arm flat-panel CT (FPCT) versus standard multi-detector CT (MDCT) shoulder arthrography using MRI-arthrography as reference standard. METHODS: Radiation dose of two different FPCT acquisitions (5 and 20 s) and standard MDCT of the shoulder were assessed using phantoms and thermoluminescence dosimetry. FPCT arthrographies were performed in 34 patients (mean age 44 ± 15 years). Different joint structures were quantitatively and qualitatively assessed by two independent radiologists. Inter-reader agreement and diagnostic performance were calculated. RESULTS: Effective radiation dose was markedly lower in FPCT 5 s (0.6 mSv) compared to MDCT (1.7 mSv) and FPCT 20 s (3.4 mSv). Contrast-to-noise ratios (CNRs) were significantly (p < 0.05) higher in FPCT 20-s versus 5-s protocols. Inter-reader agreements of qualitative ratings ranged between к = 0.47-1.0. Sensitivities for cartilage and rotator cuff pathologies were low for FPCT 5-s (40 % and 20 %) and moderate for FPCT 20-s protocols (75 % and 73 %). FPCT showed high sensitivity (81-86 % and 89-99 %) for bone and acromioclavicular-joint pathologies. CONCLUSION: Using a 5-s protocol FPCT shoulder arthrography provides lower radiation dose compared to MDCT but poor sensitivity for cartilage and rotator cuff pathologies. FPCT 20-s protocol is moderately sensitive for cartilage and rotator cuff tendon pathology with markedly higher radiation dose compared to MDCT. KEY POINTS: • FPCT shoulder arthrography is feasible with fluoroscopy and CT in one workflow. • A 5-s FPCT protocol applies a lower radiation dose than MDCT. • A 20-s FPCT protocol is moderately sensitive for cartilage and tendon pathology.

Normative values for volume and fat content of the hip abductor muscles and their dependence on side, age and gender in a healthy population.

OBJECTIVE: To determine normative values for volume and fat content of the gluteus medius (GMed) and minimus (GMin) muscle in healthy volunteers and to evaluate their dependence on age, gender and leg dominance. MATERIALS AND METHODS: The IRB approval was obtained for this study. 80 healthy volunteers (females, 40; males, 40; age range 20-62 years), divided into four age groups, were included. Fat- and water-signal-separated MR images of the pelvis were acquired on a 3.0 T MR with a 3-point mDIXON sequence. Normalized volume and fat-signal fraction (FSF) of the GMed (ViGMed, FSFGMed) and GMin (ViGMin, FSFGMin) muscles were determined. RESULTS: The overall mean volumes (normalized) and FSF ± SD: ViGMed 105.13 ± 16.30 cm(3); ViGMin 30.24 ± 5.15 cm(3); FSFGMed 8.13 ± 1.70 % and FSFGMin 9.89 ± 2.72 %. Comparing different age subgroups within each gender no significant differences were found concerning the volumes and FSFs (except FSFGMin in male subgroup aged 20-29 versus 50-62 years, P = 0.014). Comparing FSFs differences between the two genders, only in 20-29 years subgroup, FSFGMed (P =0.003) and FSFGMin (P =0.002) were greater in female. Volume differences between the two legs were not significant (P > 0.077); FSFGMed and FSFGMin (P =0.005 for both) were significantly lower in the dominant leg in female but not in male group (P = 0.454 for FSFGMed and P = 0.643 for FSFMin). CONCLUSION: No age dependency was evident for volume normative data for GMed and GMin and normative data for FSF values showed no age- or gender dependency.

Systematic analysis of the intravoxel incoherent motion threshold separating perfusion and diffusion effects: Proposal of a standardized algorithm.

PURPOSE: To systematically evaluate the dependence of intravoxel-incoherent-motion (IVIM) parameters on the b-value threshold separating the perfusion and diffusion compartment, and to implement and test an algorithm for the standardized computation of this threshold. METHODS: Diffusion weighted images of the upper abdomen were acquired at 3 Tesla in eleven healthy male volunteers with 10 different b-values and in two healthy male volunteers with 16 different b-values. Region-of-interest IVIM analysis was applied to the abdominal organs and skeletal muscle with a systematic increase of the b-value threshold for computing pseudodiffusion D*, perfusion fraction Fp, diffusion coefficient D, and the sum of squared residuals to the bi-exponential IVIM-fit. RESULTS: IVIM parameters strongly depended on the choice of the b-value threshold. The proposed algorithm successfully provided optimal b-value thresholds with the smallest residuals for all evaluated organs [s/mm2]: e.g., right liver lobe 20, spleen 20, right renal cortex 150, skeletal muscle 150. Mean D* [10(-3) mm(2)/s], Fp [%], and D [10(-3) mm(2)/s] values (±standard deviation) were: right liver lobe, 88.7 ± 42.5, 22.6 ± 7.4, 0.73 ± 0.12; right renal cortex: 11.5 ± 1.8, 18.3 ± 2.9, 1.68 ± 0.05; spleen: 41.9 ± 57.9, 8.2 ± 3.4, 0.69 ± 0.07; skeletal muscle: 21.7 ± 19.0; 7.4 ± 3.0; 1.36 ± 0.04. CONCLUSION: IVIM parameters strongly depend upon the choice of the b-value threshold used for computation. The proposed algorithm may be used as a robust approach for IVIM analysis without organ-specific adaptation.

Quantitative and qualitative MR-imaging assessment of vastus medialis muscle volume loss in asymptomatic patients after anterior cruciate ligament reconstruction.

BACKGROUND: To quantitatively and qualitatively assess vastus medialis muscle atrophy in asymptomatic patients with anterior cruciate ligament reconstruction, using the nonoperated leg as control. METHODS: Prospective Institutional Review Board approved study with written informed patient consent. Thirty-three asymptomatic patients (men, 21; women,12) with ACL-reconstruction underwent MR imaging of both legs (axial T1-weighted spin-echo and 3D spoiled dual gradient-echo sequences). Muscle volume and average fat-signal fraction (FSF) of the vastus medialis muscles were measured. Additionally, Goutallier classification was used to classify fatty muscle degeneration. Significant side differences were evaluated using the Wilcoxon test and, between volumes and FSF, using student t-tests with P-value < 0.05 and < 0.025, respectively. RESULTS: The muscle volume was significantly smaller in the operated (mean ± SD, 430.6 ± 119.6 cm(3) ; range, 197.3 to 641.7 cm(3) ) than in the nonoperated leg (479.5 ± 124.8 cm(3) ; 261.4 to 658.9 cm(3) ) (P < 0.001). Corresponding FSF was 6.3 ± 1.5% (3.9 to 9.2%) and 5.8 ± 0.9% (4.0 to 7.4%), respectively, with a nonsignificant (P > 0.025) difference. The relative muscle-volume and FSF differences were -10.1 ± 8.6% (7.1 to -30.1%) and 10.9 ± 29.4% (39.7 to 40.1%). The qualitative assessment revealed no significant differences (P > 0.1). CONCLUSION: A significant muscle volume loss of the vastus medialis muscle does exist in asymptomatic patients with ACL-reconstruction, but without fatty degeneration.

Cross-sectional area measurements versus volumetric assessment of the quadriceps femoris muscle in patients with anterior cruciate ligament reconstructions.

OBJECTIVE: Our aim was to validate the use of cross-sectional area (CSA) measurements at multiple quadriceps muscle levels for estimating the total muscle volume (TMV), and to define the best correlating measurement level. METHODS: Prospective institutional review board (IRB)-approved study with written informed patient consent. Thighs of thirty-four consecutive patients with ACL-reconstructions (men, 22; women, 12) were imaged at 1.5-T using three-dimensional (3D) spoiled dual gradient-echo sequences. CSA was measured at three levels: 15, 20, and 25 cm above the knee joint line. TMV was determined using dedicated volumetry software with semiautomatic segmentation. Pearson's correlation and regression analysis (including standard error of the estimate, SEE) was used to compare CSA and TMV. RESULTS: The mean ± standard deviation (SD) for the CSA was 60.6 ± 12.8 cm(2) (range, 35.6-93.4 cm(2)), 71.1 ± 15.1 cm(2) (range, 42.5-108.9 cm(2)) and 74.2 ± 17.1 cm(2) (range, 40.9-115.9 cm(2)) for CSA-15, CSA-20 and CSA-25, respectively. The mean ± SD quadriceps' TMV was 1949 ± 533.7 cm(3) (range, 964.0-3283.0 cm(3)). Pearson correlation coefficient was r = 0.835 (p < 0.01), r = 0.906 (p < 0.01), and r = 0.956 (p < 0.01) for CSA-15, CSA-20 and CSA-25, respectively. Corresponding SEE, expressed as percentage of the TMV, were 15.2%, 11.6% and 8.1%, respectively. CONCLUSION: The best correlation coefficient between quadriceps CSA and TMV was found for CSA-25, but its clinical application to estimate the TMV is limited by a relatively large SEE. KEY POINTS: • Cross-sectional area was used to estimate QFM size in patients with ACL-reconstruction • A high correlation coefficient exists between quadriceps CSA and volume • Best correlation was seen 25 cm above the knee joint line • A relatively large standard error of the estimate limits CSA application.

Normative MR cervical spinal canal dimensions.

PURPOSE: To provide normal values of the cervical spinal canal and spinal cord dimensions in several planes with respect to spinal level, age, sex, and body height. MATERIALS AND METHODS: This study was approved by the institutional review board; all individuals provided signed informed consent. In a prospective multicenter study, two blinded raters independently examined cervical spine magnetic resonance (MR) images of 140 healthy volunteers who were white. The midsagittal diameters and areas of spinal canal and spinal cord, respectively, were measured at the midvertebral levels of C1, C3, and C6. A multivariate general linear model described the influence of sex, body height, age, and spinal level on the measured values. RESULTS: There were differences for sex, spinal level, interaction between sex and level, and body height, while age had significant yet limited influence. Normative ranges for the sagittal diameters and areas of spinal canal and spinal cord were defined at C1, C3, and C6 levels for men and women. In addition to a calculation of normative ranges for a specific sex, spinal level, age, and body height data, data for three different height subgroups at 45 years of age were extracted. These results show a range of the spinal canal dimensions at C1 (from 10.7 to 19.7 mm), C3 (from 9.4 to 17.2 mm), and C6 (from 9.2 to 16.8 mm) levels. CONCLUSION: The dimensions of the cervical spinal canal and cord in healthy individuals are associated with spinal level, sex, age, and height. Online supplemental material is available for this article.

Imaging of acute cervical spine trauma: when to obtain which modality.

The current knowledge and evidence around the merits of different imaging modalities for the evaluation of cervical spine injuries are reviewed. The National Emergency X-Radiography Use Study, Canadian Cervical Spine rule, and American College of Radiology appropriateness criteria are reviewed and summarized. The advantages and disadvantages of available imaging modalities for selected cervical spine injury patterns are also illuminated to simplify the decision making on when to use which modality.

Ligaments of the Lisfranc joint in MRI: 3D-SPACE (sampling perfection with application optimized contrasts using different flip-angle evolution) sequence compared to three orthogonal proton-density fat-saturated (PD fs) sequences.

PURPOSE: To compare the detection rate and visibility of the ligaments in the Lisfranc joint with a single 3D (-SPACE) MR sequence and three orthogonal PD fat-saturated sequences. MATERIALS AND METHODS: Thirty-one asymptomatic feet and 15 patients with posttraumatic pain in the Lisfranc joint were evaluated with a 3D-SPACE-sequence (0.5 mm section thickness, acquisition time 10:22 min, secondary reformations) and three orthogonal PD fs sequences (2 mm section thickness, 9:20 min). The Lisfranc-ligament, the dorsal and plantar tarsometatarsal ligaments (TMT), the dorsal, interosseous, and plantar intermetatarsal ligaments (IMT) (24 ligaments for each foot) were assessed. RESULTS: In asymptomatic feet, 692 ligaments were detected with the SPACE sequence, thereof 90.6 % exhibited normal signal, and most (96.9 %) were completely visible on one single image. A total of 659 ligaments were detected with the PD fs sequence, thereof 86.6 % yielded normal signal, and 28.5 % were completely visible on one single image. In patients, 327 ligaments were detected with SPACE, thereof 50.6 % appeared completely visible with high signal. On PD fs, 308 ligaments were detected, 42.2 % of the ligaments had high signals. CONCLUSIONS: The ligaments of the Lisfranc joint are better detected with a single 3D-SPACE sequence and secondary reformations than with three orthogonal PD fs sequences.

Access routes and reported decision criteria for lumbar epidural drug injections: a systematic literature review.

PURPOSE: To review lumbar epidural drug injection routes in relation to current practice and the reported criteria used for selecting a given approach. MATERIAL AND METHODS: This was a HIPPA-compliant study. Employing a systematic search strategy, the MEDLINE and EMBASE databank as well as the Cochrane Library were searched for studies on epidural drug injections. The following data were noted: access route, level of injection, use of image guidance, and types and doses of injected drugs. Justifications for the use of a particular route were also noted. Data were presented using descriptive statistics. RESULTS: A total of 1,211 scientific studies were identified, of which 91 were finally included (7.5%). The interlaminar access route was used in 44 of 91 studies (48.4%), the transforaminal in 37 of 91 studies (40.7%), and the caudal pathway in 26 of 91 studies (28.6%). The caudal pathway was favored in the older studies whereas the transforaminal route was favored in recent studies. Decision criteria related to correct needle placement, concentration of injected drug at lesion site, technical complexity, costs, and potential complications. Injection was usually performed on the level of the lesion using local anesthetics (71 of 91 studies, 78.0%), steroids (all studies) and image guidance (71 of 91 studies, 78%). CONCLUSIONS: The most commonly used access routes for epidural drug injection are the interlaminar and transforaminal pathways at the level of the pathology. Transforaminal routes are being performed with increasing frequency in recent years.

Surgical hip dislocation versus hip arthroscopy for femoroacetabular impingement: clinical and morphological short-term results.

INTRODUCTION: Surgical hip dislocation (SHD) is an accepted standard to treat femoroacetabular impingement (FAI). However, arthroscopic techniques have gained widespread popularity and comparable results are reported. The purpose of this prospective comparative study was to test the hypothesis that, when compared to SHD, hip arthroscopy (HA) results in faster recovery, better short-term outcome, and equivalent morphological corrections. MATERIALS AND METHODS: 38 patients presenting with clinically and morphologically verified isolated FAI were allocated to either HA or SHD. Morphological evaluation consisted of pre- and postoperative X-rays, and arthro-MRI. Demographic data, sport activities, hospital stay, complications, and the time off work were recorded. The subjective hip value, WOMAC, HHS, and hip abductor strength were measured up to 1 year. RESULTS: Shorter hospital stay and time off work, less pain at 3 months and 1 year, higher subjective hip values at 6 weeks and 3 months, and better WOMAC at 3 months were seen after HA. The HHS and the hip abductor strengths were higher in the HA group. However, morphological corrections at the head-neck-junction achieved by HA showed some overcorrection when compared to SHD. Labral refixation was performed less frequent in the HA group. CONCLUSION: When compared to SHD, HA results in faster recovery and better short-term outcome. However, some overcorrection of the cam deformity and limited frequency of labrum refixation with HA in this study may have a negative impact on long-term outcome.

Reduction of metal artifacts in patients with total hip arthroplasty with slice-encoding metal artifact correction and view-angle tilting MR imaging.

PURPOSE: To compare the new "warp" sequence (slice-encoding metal artifact correction [SEMAC], view-angle tilting [VAT], and increased bandwidth) for the reduction of both through-plane and in-plane magnetic resonance (MR) artifacts with current optimized MR sequences in patients with total hip arthroplasty (THA). MATERIALS AND METHODS: The institutional review board issued a waiver for this study. Forty patients with THA were prospectively included. SEMAC, VAT, and increased bandwidth were applied by using the warp turbo-spin-echo sequence at 1.5 T. Coronal short tau inversion-recovery (STIR)-warp and transverse T1-weighted warp (hereafter, T1-warp) images, as well as standard coronal STIR and transverse T1-weighted sequence images optimized with high bandwidth (STIR-hiBW and T1-hiBW), were acquired. Fifteen additional patients were examined to compare the T1-warp and T1-hiBW sequence with an identical matrix size. Signal void was quantified. Qualitative criteria (distinction of anatomic structures, blurring, and noise) were assessed on a five-point scale (1, no artifacts; 5, not visible due to severe artifacts) by two readers. Abnormal imaging findings were recorded. Quantitative data were analyzed with a t test and qualitative data with a Wilcoxon signed rank test. RESULTS: Signal void around the acetabular component was smaller for STIR-warp than STIR-hiBW images (21.6 cm2 vs 42.4 cm2; P=.0001), and for T1-warp than T1-hiBW images (17.6 cm2 vs 20.2 cm2; P=.0001). Anatomic distinction was better on STIR-warp compared with STIR-hiBW images (1.9-2.8 vs 3.6-4.6; P=.0001), and on T1-warp compared with T1-hiBW images (1.3-2.8 vs 1.8-3.2; P<.002). Distortion, blurring, and noise were lower with warp sequences than with the standard sequences (P=.0001). Almost half of the abnormal imaging findings were missed on STIR-hiBW compared with STIR-warp images (55 vs 105 findings; P=.0001), while T1-hiBW was similar to T1-warp imaging (50 vs 55 findings; P=.06). CONCLUSION: STIR-warp and T1-warp sequences were significantly better according to quantitative and qualitative image criteria, but a clinically relevant artifact reduction was only present for STIR images.

Are there cervical spine findings at MR imaging that are specific to acute symptomatic whiplash injury? A prospective controlled study with four experienced blinded readers.

PURPOSE: To compare the magnetic resonance (MR) imaging findings in patients with acute whiplash injury with those in matched control subjects. MATERIALS AND METHODS: In a prospective multicenter controlled study, from 2005 to 2008, 100 consecutive patients underwent 1.5-T MR imaging examinations of the cervical spine within 48 hours after a motor vehicle accident. Findings in these patients were compared in a blinded fashion with those in 100 age- and sex-matched healthy control subjects. Four blinded independent readers assessed the presence of occult vertebral body and facet fractures, vertebral body and facet contusions, intervertebral disk herniations, ligamentum nuchae strains, ligamentum nuchae tears, muscle strains or tears, and perimuscular fluid. Accuracy (as compared with clinical findings) and interobserver reliability were calculated. RESULTS: Accuracy of MR imaging and interreader reliability were generally poor (sensitivity, 0.328; specificity, 0.728; positive and negative likelihood ratios, 1.283 and 1.084, respectively). MR imaging findings significantly associated with whiplash injuries were occult fracture (P<.01), bone marrow contusion of the vertebral body (P=.01), muscle strain (P<.01) or tear (P<.01), and the presence of perimuscular fluid (P<.01). While 10 findings thought to be specific for whiplash trauma were significantly (P<.01) more frequent in patients (507 observations), they were also regularly found in healthy control subjects (237 observations). There were no serious occult injuries that required immediate therapy. CONCLUSION: MR imaging at 1.5 T reveals only limited evidence of specific changes to the cervical spine and the surrounding tissues in patients with acute symptomatic whiplash injury compared with healthy control subjects.

Cervical muscle area measurements in whiplash patients: Acute, 3, and 6 months of follow-up.

PURPOSE: To investigate the role of the cervical spine muscles in whiplash injury. We hypothesized that (i) cervical muscle hypotrophy would be evident after a 6-month follow-up and, (ii) cervical muscle hypotrophy would correlate with symptom persistence probably related to pain or inactivity. MATERIALS AND METHODS: Ninety symptomatic patients (48 females) were recruited from our emergency department and examined within 48 h, and at 3, and 6 months after a motor vehicle accident. MRI cross-sectional muscle area (CSA) measurements were performed bilaterally of the cervical extensor and sternocleidomastoid muscles using transverse STIR (Short Tau inversion Recovery) sequences at the C2 (deep and total dorsal cervical extensor muscles), C4 (sternocleidomastoid muscles) and C5 (deep and total dorsal cervical extensor muscles) levels. Two blinded raters independently performed the measurements at each time point. First, CSA changes over time were analyzed and, second, CSAs were correlated with clinical outcomes (EuroQuol, Whiplash Disability Score, neck pain intensity [VAS], cervical spine mobility). RESULTS: There was a high agreement of CSA measurements between the two raters. Women consistently had smaller CSAs than men. There were no significant changes of CSAs over time at any of the three levels. There were no consistent significant correlations of CSA values with the clinical scores at all time points except with the body mass index. CONCLUSION: Our results do not support a major role of cervical muscle volume in the genesis of symptoms after whiplash injury.

STIR sequence with increased receiver bandwidth of the inversion pulse for reduction of metallic artifacts.

OBJECTIVE: The purpose of this study was to evaluate a STIR sequence with an optimized inversion pulse that entails use of increased receiver bandwidth for metal artifact reduction. CONCLUSION: Image distortion, artifacts, insufficient fat suppression, and detection of relevant findings improved with the STIR optimized inversion pulse, which was associated with significant artifact reduction.

Added value of combined acromiohumeral distance and critical shoulder angle measurements on conventional radiographs for the prediction of rotator cuff pathology.

Purpose: To investigate the role of acromiohumeral distance (AHD) and critical shoulder angle (CSA) measurements from conventional radiographs (CR) in isolation and combined (prognostic index PIAHD-CSA) as predictors of full thickness rotator cuff tendon tears (RCT) and critical fatty degeneration (CFD; i.e. as much fat as muscle). Method: In this retrospective study AHD and CSA were measured in 127 CR. MR arthrograms served as reference standard and were screened for RCT and CFD. Statistical analysis for inter-reader agreement, Spearman's rank correlation, linear stepwise regression and logistic regression for AHD and CSA with ROC analyses including PIAHD-CSA were performed. Results: In 90 subjects (17 females, mean age 36.1 ± 14.1) no RCT were found on MR imaging and served as control group. In 37 patients (13 females, mean age 58.7 ± 13.2) ≥ one RCT was found. Inter-reader agreements rated between к = 0.42-0.82 for categorical and 0.91-0.96 for continuous variables. No significant correlation of AHD and CSA with either age or sex was seen (p = 0.28 and p = 0.74, respectively). Case group had significantly smaller mean AHD (8.7 ± 3.2 vs. 10.8 ± 2.2 mm; p < 0.001) and larger mean CSA (36.5 ± 4.5° vs. 33.1 ± 4.0°; p < 0.001). PIAHD-CSA increased diagnostic performance for prediction of RCT and CFD (AUC = 0.78 and 0.71), compared to isolated AHD (0.74 and 0.71) and CSA (0.71 and 0.66). Conclusions: AHD and CSA do not depend on age or sex but differ significantly between healthy and pathologic rotator cuffs. A decreased AHD is most influenced by infraspinatus muscle atrophy and fatty degeneration. Combined PIAHD-CSA increases diagnostic performance for predicting RCT and CFD.

Cervical muscle area measurements in acute whiplash patients and controls.

PURPOSE: To quantitatively compare the muscle cross-sectional areas (CSAs) of the cervical muscles in symptomatic acute whiplash patients versus healthy controls. We hypothesized, that symptomatic whiplash patients have smaller cervical muscle CSAs than matched controls and that smaller cervical muscle CSAs in women might explain that women more frequently are symptomatic after whiplash injury than men. MATERIALS AND METHODS: Prospective controlled study. Thirty-eight consecutive acute whiplash patients were examined within 48 h after a motor vehicle accident and 38 healthy age- and sex-matched controls, each half female, half male, were examined with the same protocol. MRI CSA measurements were performed of the deep and total cervical extensor muscles as well as the sternocleidomastoid muscles using transversal STIR (Short T1 Inversion Recovery) sequences on level C2, C4, and C5 by two blinded raters. Clinical symptoms were assessed with patient questionnaires (EuroQuol 5D, Specific Whiplash Questionnaire, head- and neck pain intensity [VAS]). RESULTS: Agreement of measurements between the two raters was high (intraclass correlation 0.52 to 0.85 for the different levels). No significant difference in age and body mass index were seen between patients and controls and the distribution of genders across groups was identical. There were no significant differences between patients and controls for all CSAs. Women had consistently smaller CSAs than men. The CSAs showed no significant correlation with the pain intensity of neck pain and headache but a consistent tendency of less neck pain and more headache with greater CSAs. CONCLUSION: This small study provides no evidence that subjects with smaller CSAs of cervical extensor muscles have a higher risk in developing symptoms after a whiplash injury and confirms smaller CSA in women.