The gymnasts’ hip and groin: a magnetic resonance imaging study in asymptomatic elite athletes

Objective

Specific patterns of developmental adaptation of the proximal femur have been recognized in some sports. Gymnastics are characterized by repetitive axial loading and hip rotations in combination with extreme hip positions. It is unknown how and if these forces can affect an immature skeleton in the long term. We sought to evaluate this, by means of magnetic resonance imaging of the hip and groin of such elite asymptomatic athletes.

Materials and methods

We performed a case-control comparative MR imaging study of both hips and groin of 12 (7 male, 5 female) skeletally mature young (mean age 18.6 years) asymptomatic international level gymnasts with a minimum of 10 years’ training with age-matched non-athletes. At the time of recruitment, none of the athletes had a recorded musculoskeletal complaint or injury in the anatomical area around the hip.

Results

The study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal and are considered to be the result of adaptational changes to the specific sport: high centre–column–diaphysis angle (coxa valga140° on average), ligamentum teres hypertrophy, friction of the iliotibial band with oedema surrounding the greater trochanter, and a high incidence (62.5 %) of radiological appearances of ischiofemoral impingement.

Conclusion

Our study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal. These findings were in asymptomatic subjects; hence, radiologists and sports physicians should be aware of them in order to avoid unnecessary treatment.     

T1rho, T2 and focal knee cartilage abnormalities in physically active and sedentary healthy subjects versus early OA patients—a 3.0-Tesla MRI study

(1) To assess the degree of focal cartilage abnormalities in physically active and sedentary healthy subjects as well as in patients with early osteoarthritis (OA). (2) To determine the diagnostic value of T2 and T1rho measurements in identifying asymptomatic physically active subjects with focal cartilage lesions. Thirteen asymptomatic physically active subjects, 7 asymptomatic sedentary subjects, and 17 patients with mild OA underwent 3.0-T MRI of the knee joint. T1rho and T2 values, cartilage volume and thickness, as well as the WORMS scores were obtained. Nine out of 13 active healthy subjects had focal cartilage abnormalities. T1rho and T2 values in active subjects with and without focal cartilage abnormalities differed significantly (p < 0.05). T1rho and T2 values were significantly higher (p < 0.05) in early OA patients compared to healthy subjects. T1rho measurements were superior to T2 in differentiating OA patients from healthy subjects, yet T1rho was moderately age-dependent. (1) Active subjects showed a high prevalence of focal cartilage abnormalities and (2) active subjects with and without focal cartilage abnormalities had different T1rho and T2 composition of cartilage. Thus, T1rho and T2 could be a parameter suited to identify active healthy subjects at higher risk for developing cartilage pathology.     

A comparison of high b-value vs standard b-value diffusion-weighted magnetic resonance imaging at 3.0?T for medulloblastomas

Objective:

To investigate the utility of diffusion-weighted (DW) MRI using high b-value vs standard b-value for patients with medulloblastoma (MB). Minimum apparent diffusion coefficient (ADC_MIN) values were also compared with tumour cellularity.

Methods:

High and standard b-value DW images were obtained for 17 patients with MB. The number and location of the lesions, signal intensities (SIs), signal-to-noise ratios (SNRs), contrast-to-noise ratios, contrast ratios (CRs) and ADCs of the lesions were compared. Tumour cellularity was also measured and compared with ADC_MIN values.

Results:

All 20 lesions were hyperintense on the DW MR images with high and standard b-values. Four additional lesions were revealed on high b-value, and all 24 lesions were more conspicuous at high b-value. SI, SNR and ADC values for the lesions were lower in the high b-value images than in the standard b-value images. The ADC_MIN value at b = 3000 s mm⁻² was more significantly associated with tumour cellularity than that at b = 1000 s mm⁻². CR values were significantly higher in the high b-value images than in the standard b-value images.

Conclusion:

DW imaging using high b-value may be beneficial for detecting additional, less prominent lesions and may improve the contrast between MB lesions and normal tissue. A stronger inverse correlation with tumour cellularity was identified using the ADC_MIN values at high b-value.

Advances in knowledge:

This study demonstrates the superiority of high b-value DW imaging compared with standard b-value imaging for the detection of MB lesions, especially those with subtle foci.     

Results of a prospective clinical study on the diagnostic performance of standard magnetic resonance imaging in comparison to a combination of 3 T MRI and additional CT imaging in Kienböck's disease

PurposeThis prospective clinical study examined standard wrist magnetic resonance imaging (MRI) examinations and the incremental value of computed tomography (CT) in the diagnosis of Kienböck's disease (KD) with regard to reliability and precision in the different diagnostic steps during diagnostic work-up.Materials and methodsSixty-four consecutive patients referred between January 2009 and January 2014 with positive initial suspicion of KD according to external standard wrist MRI were prospectively included (step one). Institutional review board approval was obtained. Clinical examination by two handsurgeons were followed by wrist radiographs (step two), ultrathin-section CT, and 3 T contrast-enhanced MRI (step three). Final diagnosis was established in a consensus conference involving all examiners and all examinations results available from step three.ResultsIn 12/64 patients, initial suspicion was discarded at step two and in 34/64 patients, the initial suspicion of KD was finally discarded at step three. The final external MRI positive predictive value was 47%. The most common differential diagnoses at step three were intraosseous cysts (n = 15), lunate pseudarthrosis (n = 13), and ulnar impaction syndrome (n = 5). A correlation between radiograph-based diagnoses (step two) with final diagnosis (step three) showed that initial suspicion of stage I KD had the lowest sensitivity for correct diagnosis (2/11). Technical factors associated with a false positive external MRI KD diagnosis were not found.ConclusionStandard wrist MRI should be complemented with thin-section CT, and interdisciplinary interpretation of images and clinical data, to increase diagnostic accuracy in patients with suspected KD.     

Influence of high magnetic field strengths and parallel acquisition strategies on image quality in cardiac 2D CINE magnetic resonance imaging: comparison of 1.5 T vs. 3.0 T

The aim of this paper is to examine signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality of cardiac CINE imaging at 1.5 T and 3.0 T. Twenty volunteers underwent cardiac magnetic resonance imaging (MRI) examinations using a 1.5-T and a 3.0-T scanner. Three different sets of breath-held, electrocardiogram-gated (ECG) CINE imaging techniques were employed, including: (1) unaccelerated SSFP (steady state free precession), (2) accelerated SSFP imaging and (3) gradient-echo-based myocardial tagging. Two-dimensional CINE SSFP at 3.0 T revealed an SNR improvement of 103% and a CNR increase of 19% as compared to the results obtained at 1.5 T. The SNR reduction in accelerated 2D CINE SSFP imaging was larger at 1.5 T (37%) compared to 3.0 T (26%). The mean SNR and CNR increase at 3.0 T obtained for the tagging sequence was 88% and 187%, respectively. At 3.0 T, the duration of the saturation bands persisted throughout the entire cardiac cycle. For comparison, the saturation bands were significantly diminished at 1.5 T during end-diastole. For 2D CINE SSFP imaging, no significant difference in the left ventricular volumetry and in the overall image quality was obtained. For myocardial tagging, image quality was significantly improved at 3.0 T. The SNR reduction in accelerated SSFP imaging was overcompensated by the increase in the baseline SNR at 3.0 T and did not result in any image quality degradation. For cardiac tagging techniques, 3.0 T was highly beneficial, which holds the promise to improve its diagnostic value.     

T2* mapping and delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) of glenohumeral cartilage in asymptomatic volunteers at 3 T

Objectives

To establish baseline T2* and T1_Gd values of glenohumeral cartilage at 3 T.

Methods

Forty asymptomatic volunteers (mean age: 24.8?±?2.2 years) without shoulder abnormalities were included. The MRI protocol comprised a double-echo steady-state (DESS) sequence for morphological cartilage evaluation, a gradient-echo multiecho sequence for T2* assessment, and a gradient-echo dual-flip-angle sequence for T1_Gd mapping. Statistical assessment involved a one-way analysis of variance (ANOVA) to identify the differences between various regions of the glenohumeral joint and intraclass correlation (ICC) analysis comparing repetitive T2* and T1_Gd measures to assess intra- and interobserver reliability.

Results

Both techniques revealed significant differences between superior and inferior glenohumeral cartilage demonstrating higher T2* (26.2 ms vs. 23.2 ms, P value?<?0.001) and T1_Gd (750.1 ms vs. 720.2 ms, P value?=?0.014) values in the superior regions. No trend was observed in the anterior-posterior measurement (P value range: 0.279–1.000). High intra- and interobserver agreement (ICC value range: 0.895–0.983) was noted for both T2* and T1_Gd mapping.

Conclusions

T2* and T1_Gd mapping are reliable in the assessment of glenohumeral cartilage. The values from this study can be used for comparison to identify cartilage degeneration in patients suffering from shoulder joint abnormalities.

Key Points

? T2* mapping and dGEMRIC are sensitive to collagen degeneration and proteoglycan depletion. ? This study aimed to establish baseline T2*/dGEMRIC values of glenohumeral cartilage. ? Both techniques revealed significant differences between superior and inferior glenohumeral cartilage. ? High intra-/interreader agreement was noted for both T2* mapping and dGEMRIC. ? These baseline normal values should be useful when identifying potential degeneration.     

Vacuum phenomenon: prevalence and appearance in the knee with 3 T magnetic resonance imaging

Objectives  

To determine the prevalence of vacuum phenomenon (VP) in the knee on magnetic resonance (MR) images, describe the imaging features that characterize VP, and assess how often VP mimics pathological knee lesions.     

Initial experience of correlating parameters of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging at 3.0 T in nasopharyngeal carcinoma

Purpose

To determine the correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters.

Methods

Thirty-eight newly diagnosed NPC patients were prospectively enrolled. Diffusion-weighted images (DWI) at 13 b-values were acquired using a 3.0-T MRI system. IVIM parameters including the pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f), DCE-MRI parameters including maximum slope of increase (MSI), enhancement amplitude (EA) and enhancement ratio (ER) were calculated by two investigators independently. Intra- and interobserver agreement were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Relationships between IVIM and DCE-MRI parameters were evaluated by calculation of Spearman’s correlation coefficient.

Results

Intra- and interobserver reproducibility were excellent to relatively good (ICC?=?0.887-0.997; narrow width of 95 % limits of agreement). The highest correlation was observed between f and EA (r?=?0.633, P?f and MSI (r?=?0.598, P?=?0.001). No correlation was observed between f and ER (r?=?-0.162; P?=?0.421) or D* and DCE parameters (r?=?0.125–0.307; P?>?0.119).

Conclusion

This study suggests IVIM perfusion imaging using 3.0-T MRI is feasible in NPC, and f correlates significantly with EA and MSI.

Key Points

? Assessment of tumour perfusion is important in nasopharyngeal carcinoma. ? DCE-MRI provided perfusion information with the use of intravenous contrast media. ? Perfusion information could be provided by non-invasive IVIM MRI. ? IVIM parameter f correlated with DCE-MRI parameters.     

¹H-magnetic resonance spectroscopy of the breast at 3.0-T: comparison of results obtained before and after administration of gadolinium-based contrast agent

Purpose:

To assess the effects of gadolinium‐based contrast agent (GBCA) on ¹H‐magnetic resonance spectroscopy (MRS) of the breast at 3.0‐T.

Materials and Methods:

Patients (n = 98) with breast cancer (98 lesions) underwent MRS (point‐resolved spectroscopy sequence [PRESS]; TR/TE, 2000/100 msec; voxel size, 15 × 15 × 15 mm) before the administration of GBCA. In 52 of those patients, MRS was also performed after the administration of GBCA. The voxel‐of‐interest (VOI) was placed by referring to the noncontrast‐enhanced MRI (diffusion‐weighted images combined with fat‐suppressed T2‐weighted images). We reviewed and graded the appropriateness of VOI location compared to the correlating enhancement lesions. Integral values of the choline peak at a frequency of 3.2 ppm on MRS were compared before and after the administration of GBCA.

Results:

The VOI was placed correctly in 64 lesions (65%), although the VOI was placed outside the targeted lesion in 34 lesions (35%). The integral value of the choline peak on MRS decreased significantly after the administration of GBCA (P < 0.001).

Conclusion:

Accumulation of GBCA in breast cancer could affect the choline peak on MRS. MRS of breast cancer at 3.0‐T can be recommended to be acquired before contrast‐enhanced study; however, some problems remain in VOI placement with reference to the noncontrast‐enhanced study. J. Magn. Reson. Imaging 2012;35:717‐722. © 2011 Wiley Periodicals, Inc.     

Measurement of femoral anteversion by magnetic resonance imaging — evaluation of a new technique in children and adolescents

Anteversion of the femoral neck was measured by magnetic resonance imaging (MRI) in 19 children (37 hips) preoperatively before femoral rotation osteotomies. The results of this new technique were compared with values for anteversion obtained by computed-tomographic (CT) scanning and ultrasound. In order to determine the correlation between the three different methods and to assess their reliability, the measurements were performed independently by two observers at different times. There was a high correlation (Pearson's correlation coefficient) between MRI results and CT scan (r = 0.77) as well as MRI and sonography (r = 0.81), although the mean anteversion angles obtained by computerized tomography (34.0°, range 5–82°) and ultrasound (25.6°, 10–40°) were larger than the MRI values (23.2°, 0–65°), which can be explained by the different measurement techniques. Mean inter-rater as well as intra-rater reliability was high for MRI (r = 0.97andr = 0.97) and CT (r = 0.99andr = 0.96) but slightly less for sonography (r = 0.88andr = 0.88). MRI is a novel method for evaluating femoral anteversion that does not require ionizing raiation, allows a precise anatomical measurement and reliable results. MRI is recommended for preoperative planning of pediatric femoral rotation osteotomy cases.     

Diagnosis of pulmonary infarction in post-mortem computed tomography and post-mortem magnetic resonance imaging—a technical note

International Journal of Legal Medicine - Pulmonary thromboembolism may be accompanied by pulmonary infarction. Even though pulmonary thromboembolism (PTE) is a frequently found cause of death at...     

Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study

OBJECTIVES: To (a) compare ultrasound (US; including grey scale and colour and power Doppler) and magnetic resonance imaging (MRI; with high resolution and fat saturation sequences) with a clinical yardstick in the evaluation of chronic Achilles tendinopathy, and (b) examine whether either imaging method predicted 12 and 24 month clinical outcome. METHODS: Forty five patients with symptoms in 57 Achilles tendons were diagnosed with tendinopathy by an experienced sports medicine doctor. All patients underwent US examination (12 MHz probe) with colour and power Doppler, and 25 consecutive patients also underwent MRI with high resolution T1 weighted and STIR sequences. RESULTS: US identified abnormal morphology in 37 of the 57 symptomatic tendons (65%) and normal morphology in 19 of 28 asymptomatic tendons (68%). Baseline US findings did not predict 12 month clinical outcome. The addition of colour and power Doppler did not improve the diagnostic performance of US. MRI identified abnormal morphology in 19 of 34 symptomatic tendons (56%) and normal morphology in 15 of 16 asymptomatic tendons (94%). Lesser grades of MR signal abnormality at baseline were associated with better clinical status at 12 month follow up. CONCLUSIONS: US and MRI show only moderate correlation with clinical assessment of chronic Achilles tendinopathy. Graded MRI appearance was associated with clinical outcome but US was not.     

Efficacy of magnetic resonance imaging at 3 T compared with 1.5 T in small pituitary tumors for stereotactic radiosurgery planning

Purpose

The objective of this study was to determine the value of high-field magnetic resonance imaging and to clarify the characteristics of each image among three-dimensional gradient echo (3D-GRE), two-dimensional spin echo (2D-SE) and inversion recovery (2D-IR) sequences used as contrast-enhanced T1-weighted images for stereotactic irradiation treatment planning of sellar lesions.

Materials and methods

Pulse sequences of 2D-SE and 3D-spoiled gradient recalled acquisition in the steady state (3D-SPGR) using GRE at 1.5 T and 2D-IR and 3D-fast SPGR (3D-FSPGR) at 3 T after injection of contrast material were acquired for 14 small pituitary tumors. As quantitative methods, signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were evaluated using a region-of-interest analysis.

Results

There was no significant difference in SNR between 1.5-T SPGR and 3-T FSPGR, while 3-T IR was superior to 1.5-T SE. The 2D-SE and -IR provided significantly better CNR than 3D-GRE between tumor and normal structures.

Conclusions

Three Tesla was found to be superior to 1.5 T in distinguishing tumors from the normal sellar structure. Optimal dose planning will utilize each advantage of imaging; 3D-GRE allows high-resolution acquisition and 2D-SE and -IR can offer better tissue contrast.