Chapter 10 MR MSK Sports Medicine

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Chapter 10 MR MSK Sports Medicine

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10.01 Introduction

This fast-growing subspecialty in MSK and MRI is becoming a primary imaging modality. A wide variety of pathologies can be visualised.

Diagnosis, appropriate treatment response to therapy, and prognosis can have important implications for athletes allowing a quick return to play for the professional or elite amateur athlete.

High resolution MR imaging, as functional MRI during weight-bearing, can revolutionise orthopaedic imaging in determining the extent of injury and excluding other potential causes for the patient’s pain.

 

MRI and US (ultrasound) are the imaging modalities of choice to assess muscle injuries in athletes. Muscle injuries represent more than thirty percent of sports injuries. MRI is considered  the reference standard for evaluation of muscle injuries, since it very well depicts the extent of injuries independently of its temporal evolution. MRI is more sensitive than US for the detection of minimal injuries. Furthermore, MRI will potentially allow sports medicine physicians to more accurately estimate recovery times of athletes sustaining muscle injuries in, for example, the lower limbs, as well as identifying the risk of re-injury. In addition, clinical (and functional) assessment is a valuable to guide timing for the return to competition.

 

Typical injuries for the most common sports

Below is a short overview of the injuries athletes in different sports are most often confronted :

Courtesy: Kolja M. Thierfelder: Imaging of hip and thigh muscle injury: a pictorial review / Insights in Imaging

 

To support athletes and team doctors, radiologists should be aware of the most common differential diagnoses of delayed onset muscle soreness and post-exercise oedema as complications, such as muscle herniation, heterotopic ossification or compartment syndrome.

 

Classification of muscles injuries

To link the imaging findings and clinical examination, and to improve the assessment of the grade of severity of muscle injuries and reduce the possibility of re-injury, several injury classifications are used.

Classification is made of varying muscle architecture, lesion extension, the activities pursued when the lesion occurred, and even the mechanism.

Recently three new classifications have been rolled out:
1. Munich Consensus Classification (Mueller-Wohlfahrt et al. 2013)
2. British Classification System (pollock et al. 2014)
3. FCB Barcelona and Aspetar Classification (Valle et al. 2017)

These classifications focus on different factors that are key for a best diagnosis and prognosis:
1. mechanism of injury;
2. location of injury;
3. whether a myofascial, myotendinous or intramuscular tendon is affected;
4. whether there is retraction of fibres or not;
5. extension of oedema (and cross-sectional area);
6. whether  it is a re-injury.

These classification systems are based on the currently-available research and experience of clinical experts from different institutions with experience in assessing a high volume of muscle injuries.

Besides, a consensus is still needed to improve communication between all sports physicians and radiologists in athlete-related professional relationships concerning muscle injuries.

 

10.02 RF sequences

Biochemical-based MRI can detect early cartilaginous degenerative changes and assess cartilage repair. Techniques such as the UTE RF sequence, dual and triple TIR, T2 mapping, T1 in the rotating frame (T1rho), sodium MRI and dGEMRIC (delayed Gadolinium-Enhanced MRI of Cartilage) take advantage of changes in the complex biochemical composition of articular cartilage and allow detection of cartilaginous changes earlier than conventional MRI. The traditional PDw T(F)SE FS and the T1w RF sequence are also still very informative. In chapter 8 of this MSK e-module Microscopic Imaging is also discussed.
The RF sequences UTE and dGEMRIC are discussed in more detail in chapter 4 of this e-module and Sodium Imaging in chapter 9. The dual and triple TIR are discussed in the e-module, RF sequences.

RF sequences also used in the assessment of the skeletal muscles are:
Spectroscopy (chapter 9 of this e-module);
DTI (Diffusion Tensor Imaging) (chapter 5 of this e-module);
BOLD (Blood Oxygen Level Dependent) Imaging (e-module RF sequences part 3, chapter 5);
Molecular Imaging is discussed in several e-modules but mainly in the Neuro module chapter 4;
IVIM (Intra Voxel Incoherent Motion), discussed in the Neuro module and in this e-module chapter 9;
DWI (Diffusion Weighted Imaging) is discussed in the Neuro e-module chapter 4;
MR Elastography (discussed in the Neuro e-module chapter 9 ) can show differences in the stiffness of muscles after injury.

These RF sequences allow for non-invasive functional assessment of peripheral microvasculature in the skeletal muscles and improve the understanding of muscular and vascular physiology and changes of microcirculation.

 

Courtesy: Stephen Matzat

Quantitative MR imaging of osteoarthritis. Several quantitative MR techniques are increasingly applied to obtain biochemical information regarding cartilage health, especially in the knee. While a conventional MR image may show no major morphological defects in the cartilage (Image 1), quantitative techniques provide evidence of early osteoarthritic changes (Images 2-4). Spatial variation in dGEMRIC T1 and T1rho relaxation times in the anterior weight-bearing femoral cartilage and trochlear cartilage suggests an initial depletion of PGs (proteoglycans). T2 mapping reveals minor variations in the posterior weight-bearing femoral cartilage that are also indicative of early OA (Osteoarthritis).

 

Note regarding the dGEMRIC:

The principle of dGEMRIC is based on an interaction of specific proteins with Na+. Hence, it requires an ionic contrast interaction to visualise these processes. So, the dGEMRIC RF sequence does not work with Gadovist, Prohance, Optimark and Omniscan.

 

  • UTE (Ultra Short TE)/ ZTE (zero TE) RF sequence

In sports medicine MSK, the RF sequence is very useful for injuries and by using short minimum TE’s below 1 msec, the UTE RF sequence can show short T2 properties of tissues, including the deepest layers of articular cartilage, cortical bone, the meniscus, the cartilaginous endplate and the disco-vertebral junction.

Coronal MR images of the knee. (Image 1) PDw (TE = 55 msec) shows focal sclerosis of the subchondral bone with intact articular cartilage surface (thick arrow); (Image 2) subtracted UTE T2* image (TE 8 µsec–TE 6 msec) demonstrates a tiny focal defect of the calcified cartilage layer overlying the region of subchondral bone sclerosis

Courtesy: P. Siriwanarangsun

Sagittal MR images of the knee. The (1st image) PDFS (TE = 50 msec) image demonstrates intermediate SI of the superficial articular cartilage and low intensity of the deep layer; (2nd image) the UTE T2*w (TE = 8 µsec) reveals high intensity of the calcified cartilage layer (long thin arrow) and intermediate SI of the uncalcified cartilage (short thin arrow)

 

In order to optimise contrast and visualisation of the calcified cartilage, a subtraction technique and DIR (Double adiabatic Inversion Recovery) RF pulse sequence, among others, are used. The subtraction technique involves a two-echo acquisition whereby the longer TE (6.6 msec) acquisition is subtracted from the shorter TE (0.008 msec) acquisition, resulting in an ultrashort T2 signal in the image. The calcified cartilage layer becomes bright and readily visible compared to the adjacent cartilage and subchondral bone. The DIR technique implements an adiabatic inversion pulse to null the fat and the longer T2 tissue signal (including water), thereby unmasking the signal from the deepest calcified layer of cartilage.

An acquisition scheme for the DIR UTE sequence, where the first adiabatic inversion pulse is centered on the water peak and the second pulse is positioned on the fat peak. The longitudinal magnetisation of short-T2 species is not inverted since they experience significant transverse relaxation during the long adiabatic inversion process. UTE acquisition starts at a time delay of TI1 relative to the first inversion pulse and TI2 relative to the second inversion pulse, providing simultaneous nulling of long-T2 water and fat signals

 

Courtesy: Jiang Du

Axial MR images through the lower extremity of a healthy volunteer depicting the Achilles tendon using a conventional dual echo UTE acquisition with a TE of 8 μs (Image A) and 6 ms (image B), and a DIR UTE sequence (image D). Echo subtraction suppresses the long-T2 muscle and fat signals, increasing contrast with the Achilles tendon (image C). However, the residual long-T2 signal limits the achievable contrast. The DIR UTE sequence selectively suppresses the signal from fat and muscle, creating high contrast with the Achilles tendon (arrows)

 

Courtesy: Yiang DU

Selected UTESI images of a cadaveric ankle specimen in the axial plane show excellent depiction of the Achilles tendon with a high spatial resolution of 0.2 0.2 2.0 mm3 (acquired). Fat signals peaked at 456 Hz, leaving excellent image contrast for the Achilles tendon around the water peak

 

Courtesy: Jiang Du (incl. the Achilles tendon images)

Axial imaging of a patellar slice using PD-FSE (image A), T1-FSE (image B), UTE without (image C) and with (image D) fat saturation, and DIR UTE (image E) sequences, respectively. The DIR UTE sequence selectively suppresses signals from the superficial layers of cartilage and bone marrow fat, creating excellent image contrast with the deep radial and calcified cartilage, which is shown as a linear well-defined area of high signal (thin arrows). Effacement and thickening (thick arrows) of the deep radial and calcified cartilage is also observed

 

Publications UTE imaging:

  1. Du J., Takahashi A.M., Bae WC, Chung C.B., Bydder G.M. Dual inversion recovery, ultrashort echo time (DIR UTE) imaging: creating high contrast for short-T(2) species. Magn Reson Med 2010;63:447-55.
  2. Du J., Bydder M., Takahashi A.M., Carl M., Chung C.B., Bydder G.M. Short T2 contrast with three-dimensional ultrashort echo time imaging. Magn Reson Imaging 2011;29:470-82.
  3. Du J., Carl M., Bae W.C., Statum S., Chang E.Y., Bydder G.M., Chung C.B. Dual inversion recovery ultrashort echo time (DIR-UTE) imaging and quantification of the zone of calcified cartilage (ZCC). Osteoarthritis Cartilage 2013;21:77-85.
  4. A pilot study of short T2* measurements with ultrashort echo time imaging at 0.35T. Xiuyuan Chen, Bensheng Qiu.
  5. UTE MRI of the Osteochondral Junction. Won C. Bae, Reni Biswas, Karen Chen, Eric Y. Chang, Christine B. Chung
  6. Skeletal Muscle Quantitative Nuclear Magnetic Resonance Imaging and Spectroscopy as an Outcome Measure for Clinical Trials. Pierre G. Carlier, Benjamin Marty, +4 authors Dmitry Vlodavets

 

The UTE RF sequence can also be used in spectroscopic imaging as a time-efficient spectroscopic imaging technique based on a multi-echo interleaved variable TE UTE acquisition and is proposed for HR spectroscopic imaging of the short T2 tissues in the MSK system.

 

  • T2-T1(Rho) mapping

T2 values increase in stressed muscles and help to identify the activation or changes in muscle recruitment after muscle injuries.

T2 mapping also identifies muscle activation in specific groups and primary fatty atrophy not seen with morphologic MRI, characterised by increased T2 values. During and after activity, T2 increases and the volume can be calculated. Other advanced MRI techniques for muscle injuries are MRS which measures the muscle energy and lipid metabolism and ASL which detects the blood flow within the muscle tissues.

 

Publication:

Crema M.D., Yamada A.F., Guermazi A., Roemer F.W., Skaf A.Y. (2015) Imaging techniques for muscle injury in sports medicine and clinical relevance. Curr Rev Musculoskeletal Med 8(2):154–161.

 

Courtesy: Ali Guermazi

T2 mapping of the right leg of a 31-y-old male volunteer (image 1) before and ( image 2) 3 minutes after plantar flexion exercise. Parameters of a 3T MR system: 2D FS multi T(F)SE, matrix 128×102; FOV 160x130mm; sl th 3mm; TR 3000 ms; TE 10-130ms (13 echoes), BW300Hz/pixel, refocussing angle 180°. Note an increase in T2 values in the gastrocnemius musles after exercise (arrow) compared with  image 1

 

Courtesy: Canon

 

Courtesy: Stephan Matzat

Quantitative MRI of hip impingement. Sagittal T1w (image 1) of a patient with mixed impingement demonstrates swelling and increased signal in the anterior-superior labrum, suggesting a tear. T2 (image 2) and T1rho (image 3) maps of the same patient demonstrate applications of quantitative imaging to the hip

 

  • IVIM (intravoxel incoherent motion) is a DWI method and based on proton mobility (or diffusion) and the image contrast is created from IVIM of water protons. IVIM shows information regarding microvascular blood flow out of multiple b value diffusion acquisitions. It can determine an increase in microvascular perfusion in a specific segment after a task, and can relate this perfusion with the duration of the effort. This method has also been shown to be able to quantify micro vascularity and microstructures, evaluating the reduction of the capillaries and the degradation of myofibres which is, for example, useful in the evaluation of dermatomyositis.

It is a relatively new method and there is not, yet, a lot of data available. IVIM is based on multiple diffusion b values between B0-b100 (typically 10,20,40,80) and results vary by MRI system and manufacturer. Complex mathematical modelling has not yet shown whether Gausian, Bayesian, Kurtosis or Skweness is the best method.

Courtesy: Eric Sigmund

IVIM signal decays for soleus compartment of a healthy volunteer post-exercise. Enlargement of low b-value region are showing an IVIM effect. The images show parametric fp maps pre- and post-exercise. IVIM metrics is compared in skeletal muscle to investigate the biophysical sources of muscle diffusion contrast

 

Publications:

  1. Nguyen A., Ledoux J.B., Omoumi P., Becce F., Forget J., Federau C. (2016) Application of intravoxel incoherent motion perfusion imaging to shoulder muscles after a lift-off test of varying duration. NMR Biomed 29(1):66–73.
  2. Hiepe P., Reichenbach J. Functional muscle MRI in human calf muscle functional MRI, diffusion-weighted MRI and 31 P-MRS in exercised lower back muscles. NMR Biomed, 27 (8), 958-970.

 

  • DTI (Diffusion Tensor Imaging) of the muscle tissue allows examination of the micro-architecture, diffusion quantification of anisotropic tissues and fibre tracking, to detect minor muscle injury and to differentiate injured muscles from normal ones. Changes at microscopic level, such as z-band disruptions, can be detected.

Axial proton density fat-sat image showing a grade I muscle tear of the right semitendinosus muscle (blue arrow in image a) of a 20-year-old professional football player. In (image b) and (image c), the colour-coded maps of the right and left thigh, respectively, are presented along with the corresponding fibre tracking of both semitendinosus muscles (i.e. blue dotted line in image a), which do not demonstrate any difference for diffusion tensor imaging (DTI) metrics at the statistical analyses (i.e. student’s t-tests)

Courtesy: Chiara Giraudo and Siegried Trattnig

Grade II muscle tear of the right rectus femoris muscle (blue arrow on the axial proton density fat-saturated image in image a) of a 23-year-old professional football player. The injured area demonstrates lower fractional anisotropy (FA) (blue arrow on the FA map in image b) than the corresponding healthy contralateral muscle (white arrow on the FA map in image c)

The above images were created using STEAM-based DTI which allows an exact assessment of the injured fibres in athletes when a ratio between the injured and the contralateral muscles is applied. Even the current imaging-based classification of muscle tears could perhaps be improved to increase the accuracy of the therapeutic and prognostic management of injured athletes.

 

  • MR Elastography of the skeletal muscle can be used for studying the physiologic response of normal or damaged muscles. As mentioned before, MR elastography can identify the difference in the stiffness of muscles after injury.

Courtesy: Paul Kennedy, Edinburgh, Scotland

Demonstration of exercise-induced muscle alterations on MR elastograms produced from multifrequency MR elastography data, in a 28-year-old male volunteer. Data were acquired (image 1) before and (image 2) 48 hours after, using an exercise protocol consisting of 12 sets of eccentric contractions which were performed on a dynamometer. Increased magnitude shear stiffness is evident on the post-exercise elastogram in the rectus femoris and vastus intermedius muscle groups (arrows) when compared with the pre-exercise elastogram. The colour map  compares shear stiffness values between image 1 and image 2. MR elastogram parameters: TR/TE 1600/54; sl thickness 2m; BW 1560Hz/pixel; matrix 112×112; FOV 224x224mm; resolution 2mm isotropic; five sections; 2AC/NSA/NEX; 8 phase offsets; one motion encoding gradient cycle at 50Hz; motion encoding in phase-encoding, section-selected, and readout direction; frequencies acquired=25, 37.5, 50, 62.5Hz

 

  • PDw, T1w T(F)SE FS and T2w RF sequences

DOMS (Delayed Onset Muscle Soreness): Sagittal PDw FS image (TR/TE3670/25; FOV 26×33 cm; slice thickness 4mm; intersection gap 1mm) shows diffuse oedema of the semitendinosus muscle (arrows) in this soccer player complaining of pain that developed 36 hours after intense training. The classic feathery pattern of strain is not observed in this case, and no fibre disruption is depicted. There is no associated perifascial fluid.

 

 

 

 

 

 

 

Courtesy: Ali Guermazi

 

Compartment syndrome affecting the extensor and anterior compartments of the right leg. Image 1 axial T2w FS image (TR/TE 3900/52; FOV 20×20 cm; slice thickness 5mm; gap 1mm. Image 2: T1w FS after intravenous Gadolinium injection (TR/TE 824/18). Note the extensive muscle oedema (arrows in image 1) and the extensive lack of enhancement after intravenous contrast agent injection (arrows image 2), indicating compromised blood supply

 

Courtesy: Kolja M. Thierfelder

Coronal (image 1) and axial STIR (image 2). Feathery oedema around haematoma within the M. vastus intermedius after blunt direct trauma

 

  • Sodium Imaging

    Courtesy: Jordan C., Ph.D., Stanford Dept. of Bioengineering

    Quantitative MR imaging of ACL tear knees. T1rho mapping (Image A and B) is applied to demonstrate the traumatic effects of ACL tear on cartilage biochemistry, compared to healthy controls. Increased heterogeneity of T1rho relaxation times within weeks of injury (image B) suggests these changes occur along with the traumatic event. Sodium imaging (images C and D) is also applied to reveal the impact of ACL tear on GAG content

 

  • BOLD MRI is based on the different magnetic properties of oxy- and deoxyhaemoglobin and the blood is used as an endogenous contrast agent. BOLD can depict micro-vascularisation, metabolism, vascular insufficiency and hyperoxia for evaluating skeletal muscle physiology.

As there is a microcirculation component to almost all diseases, the use of it in skeletal muscles shows the sensitivity for changes of the physiological oxygen supply and demand.

Even ASL (Arterial Spin Labelling) is used for perfusion imaging during exercise: (Frank L.R., Wong E.C., Haseler L.J., Buxton R.B.. Dynamic imaging of perfusion in human skeletal muscle during exercise with arterial spin labeling.  Magn Reson Med. 1999; 42 258-267)

Courtesy: Noseworthy M.D.
Data from gastrocnemius (fast-twitch) and soleus (slow-twitch) muscle before and immediately following strenuous exercise. Hyperoxia was applied as the stimulus for BOLD signal modulation. The BOLD contrast was greater in the soleus at rest. In addition, the application of exercise resulted in high BOLD contrast in the soleus, as assessed through a number of changed pixels and the area under the impulse response function

 

Publications BOLD Imaging / fMRI:

Dimmick S., Rehnitz C., Weber M.A., Linklater J.M. (2014): MRI of muscle injuries. In: Weber M.A. (editor) Magnetic Resonance Imaging of the Skeletal Musculature. 2014, Springer-Verlag Berlin Heidelb. p. 187–219)

  • Stainsby J.A., Wright G.A. Monitoring blood oxygen state in muscle microcirculation with transverse relaxation. Magn Reson Med . 2001; 45 662-672
  • Noseworthy M.D., Kim J.K., Stainsby J.A., Stanisz G.J., Wright G.A. Tracking oxygen effects on MR signal in blood and skeletal muscle during hyperoxia exposure.  J Magn Reson Imaging . 1999; 9 814-820
  • Saab G., Thompson R.T., Marsh G.D. Effects of exercise on muscle transverse relaxation determined by MR imaging and in vivo relaxometry.  J Appl Physiol. 2000; 88 226-233
  • Saab G, Thompson R.T. Marsh GD Multicomponent T2 relaxation of in vivo skeletal muscle.  Magn Reson Med. 1999; 42 150-157
  • Hennig J., Scheffler K., Schreiber A. Time resolved observation of BOLD effect in muscle during isometric exercise. Proc Intl Soc Mag Reson Med . 2000; 8 122
  • Meyer R., McCully K., Reid R.W., Prior B. BOLD MRI and NIRS detection of transient hyperemia after single skeletal muscle contractions. Proc Intl Soc Mag Reson Med. 2001; 9 135
  • Brock R.W., Tschakovsky M.E., Shoemaker J.K., Halliwill J.R., Joyner M.J., Hughson R.L. Effects of acetylcholine and nitric oxide on forearm blood flow at rest and after a single muscle contraction. J Appl Physio . 1998; 85 2249-2254
  • Meyer R.A., Prior B.M. Functional magnetic resonance imaging of muscle. Exerc Sport Sci Rev. 2000; 28 89-92

 

  • Molecular Imaging and MRS (MR Spectroscopy)

Molecular Imaging shows how the body is functioning, and how to measure its chemical and biological processes.

Most of the molecular imaging methods are currently done only with PET, SPECT and MRS imaging. MRS measures changes in proton/nuclei excitation or relaxation related with various metabolites, such as choline, pyruvate, lactate, lipids, and polyamines, among others. Several MRS techniques, including 1H, 19F, 31P, and 13C MRS, have been developed: clinical applications also include MSK diseases.

1H-MRS in sports medicine is mostly used for short-term muscle energy metabolism, 31PMRS for the observation of high energy phosphates and 13C MRS to investigate muscular glycogen. It is a field in full research.

A 1H-MRS method is used to quantify IMCL (intramyocellular lipids) non-invasively. Nowadays, little is known about the regulation of this lipid pool. During prolonged exercise of moderate intensity, non-plasma-derived fatty acids play an important role as an energy source; lipids located within the skeletal muscle are a major source for these fatty acids. Studies are done before and after exercising at different workloads and duration. For example, intra- and extramyocellular lipids can be quantified by 1H-MRS in the TA (tibialis anterior) and SOL (soleus) muscles prior to and after an exercise session.

IMCL can be mobilised after heavy exercise within hours and recovered within days. Recovery time depends on time constant, delay before regeneration and overshoot and individual recovery can be determined.

EMCL (extramyocellular lipids) can be found along muscles in fasciae and in subcutaneous fat layers. This fat is metabolically relatively inactive, but frequently capable of providing a large fraction of substrate during very low intensity exercise. IMCL are more accessible for mitochondrial aerobic metabolism and are well used at higher work intensities.

1H-MRS Protocol for muscles (1.5T)

A surface coil should be used that is adapted to the area. Imaging parameters for the MRI should be chosen to separate of muscles and fasciae and can be done by a GRE RF sequence flip angle 30°, TR 100, TE 6.8ms. Water presaturation and outer volume suppression can be used for single voxel MRS and optimised PRESS RF sequence, TE 20ms, TR 3000ms, 128 acquisitions and 16 phase rotation steps. Voxel dimensions 10x10x20mm3 can be used.

Courtesy: Xin Wang

The T2w MRI image shows voxel location used for MRS in one subject, and the corresponding water suppressed spectrum from that region. Signals assigned to unsaturated fats (-CH2=CH2-), water (H2O), trimethylamines (TMA), creatine (Cr – both CH3 and CH2 groups at 3.0 and 3.9 ppm, respectively), extra- and intra-myocellular lipids respectively (EMCL and IMCL)

 

Image 1:  axial PDw FS image of a footballer’s left calf muscle showing subtle oedema in the deep lateral soleus musculotendinous junction consistent with minor functional or very low grade structural injury

Image 2: axial PDw FS image of a footballer’s right thigh showing a localised structural defect at the biceps femoris musculotendinous junction with high signal extending from that into the myofascial space consistent with a moderate partial muscle tear (Munich Classification Type 3B)

Courtesy: Toshiba, nowadays Canon

MRS of soleus muscle to assess carnosine content as an indicator of type 2 “fast twitch” muscle fibre proportion

For the exact chemical shift of carnosine, spectra were frequency aligned and referenced to the residual water peak at 4.7 ppm.

Carnosine (β-alanyl-L-histidine) is a dipeptide present in the brain and skeletal muscle and plays a buffering role in the physiological pH range during skeletal muscle contraction. 1H MRS can be used to quantify the muscle carnosine content in a non-invasive way. Oral β-alanine supplements can be used to by e.g. sprinters to elevate the muscle carnosine.

Example of an MRS protocol on a 3T MR system:

Single voxel PRESS TR/TE 2000/30ms, VOI 12x30x40 mm3, 256 AC/NEX/NSA, 1024 datapoints, spectral width 1200 Hz (Radiology, Ghent University Hospital, Belgium)

 

Publications:

Ekstrand J., Hagglund M., Walden M. Epidemiology of muscle injuries in professional football (soccer). Am J Sports Med. 2011;39:1226–32.

Elliott M.C., Zarins B., Powell J.W., Kenyon C.D. Hamstring muscle strains in professional football players: a 10-year review. Am J Sports Med. 2011;39:843–50.

Ekstrand J., Healy J.C., Walden M., Lee J.C., English B., Hagglund M. Hamstring muscle injuries in professional football: the correlation of MRI findings with return to play. Br J Sports Med. 2012;46:112–7. Largest study evaluating the relationship between MRI findings of hamstring injuries and return to play in professional football.

Askling C.M., Tengvar M., Saartok T., Thorstensson A. Proximal hamstring strains of stretching type in different sports: injury situations, clinical and magnetic resonance imaging characteristics, and return to sport. Am J Sports Med. 2008;36:1799–804.

Cohen S.B., Towers J.D., Zoga A. et al. Hamstring injuries in professional football players: magnetic resonance imaging correlation with return to play. Sports Health. 2011;3:423–30.

Kerkhoffs G.M., van Es N., Wieldraaijer T., Sierevelt I.N., Ekstrand J., van Dijk C.N. Diagnosis and prognosis of acute hamstring injuries in athletes. Knee Surg Sports Traumatol Arthrosc. 2013;21:500–9. Important literature review for the identification of relevant diagnostic and prognostic features of acute hamstring injuries, including clinical and imaging assessments.

Koulouris G., Connell D.A., Brukner P., Schneider-Kolsky M. Magnetic resonance imaging parameters for assessing risk of recurrent hamstring injuries in elite athletes. Am J Sports Med. 2007;35:1500–6.

Lee J.C., Mitchell A.W., Healy J.C. Imaging of muscle injury in the elite athlete. Br J Radiol. 2012;85:1173–85.

Hayashi D., Hamilton B., Guermazi A., de Villiers R., Crema M.D., Roemer F.W. Traumatic injuries of thigh and calf muscles in athletes: role and clinical relevance of MR imaging and ultrasound. Insights Imag. 2012;3:591–601.

Comin J., Malliaras P., Baquie P., Barbour T., Connell D. Return to competitive play after hamstring injuries involving disruption of the central tendon. Am J Sports Med. 2013;41:111–5. First study demonstrating the relevance of central tendon involvement in muscle strain regarding the time of recovery of athletes.

Silder A., Sherry M.A., Sanfilippo J., Tuite M.J., Hetzel S.J., Heiderscheit B.C. Clinical and morphological changes following 2 rehabilitation programmes for acute hamstring strain injuries: a randomised clinical trial. J Orthop Sports Phys Ther. 2013;43:284–99. Relevant follow-up randomized clinical trial including athletes with hamstring injuries, including clinical and MRI assessments at baseline and follow-up.

Lodi R., Muntoni F., Taylor J. et al. Correlative MR imaging and 31P-MR spectroscopy study in sarcoglycan deficient limb girdle muscular dystrophy. Neuromuscul Disord. 1997;7:505–11.

Tawara N., Nitta O., Kuruma H., Niitsu M., Itoh A. T2 mapping of muscle activity using ultrafast imaging. Magn Reson Med Sci. 2011;10:85–91

Baffa A.P., Felicio L.R., Saad M.C., Nogueira-Barbosa M.H., Santos A.C., Bevilaqua-Grossi D. Quantitative MRI of vastus medialis, vastus lateralis and gluteus medius muscle workload after squat exercise: comparison between squatting with hip adduction and hip abduction. J Hum Kinet. 2012;33:5–14. Nice demonstration of the usefulness of quantitative T2 assessment of muscle recruitment after different exercises applied to the lower limbs.

 

 

10.03 Clinical applications, some examples

  • Sports hernias or athletic pubalgia;

Many athletes with a diagnosis of “sports hernia” or “athletic pubalgia” have a spectrum of related pathologic conditions resulting from musculotendinous injuries and subsequent instability of the pubic symphysis without any finding of inguinal hernia at physical examination.

Courtesy: OrthoInfo

A sports hernia is a painful, soft tissue injury that occurs in the groin area. It occurs most often during sports that require sudden changes of direction or intense twisting movements.

A sports hernia is a different injury to a traditional abdominal hernia but may lead to it. A sports hernia is a strain or tear of any soft tissue (muscle, tendon, ligament) in the lower abdomen or groin area.

Courtesy: Radsource

Image 1: T2w FS coronal, Image 2: PDw FS axial, and image 3: PDw FS sagittal images

Image 1 demonstrates mild hypertrophic bony and capsular changes at the symphysis pubis with diffuse bilateral marrow edema. Image 2. axial image demonstrates increased signal anterior to and within the anterosuperior pubic body, subjacent to the common adductor-rectus abdominis aponeurosis insertion, suggesting chronic tenoperiosteal avulsion. Image 3 is a sagittal image, obtained to the left of midline, confirms a small tenoperiosteal avulsion subjacent to the adductor longus and common adductor-rectus abdominis aponeurosis with subjacent resorptive bony changes

 

PyeongChang 2018

  • when intra-articular pathology is suspected, MR arthrography is the imaging study of choice;
  • labral tears and FAI (Femoro Acetbualar Impingement);
  • differential considerations in imaging with respect to groin pain include the relatively common partial or complete muscle tears;
  • a relatively newly described lesion is the Morel-Lavallée lesion;

The Morel-Lavallée lesion is a closed soft-tissue degloving injury commonly associated with high-energy trauma. The thigh, hip, and pelvic region are the most commonly affected locations. Timely identification and management of a Morel-Lavallée lesion is crucial because distracting injuries in the polytraumatised patient can result in a missed or delayed diagnosis. Bacterial colonisation of these closed soft-tissue injuries has resulted in their association with high rates of perioperative infection. Recently, MRI has been used to characterise and classify these lesions. Definitive management is dictated by the size, location, and age of the injury and ranges from percutaneous drainage to open débridement and irrigation. Chronic lesions may lead to the development of pseudocysts and contour deformities of the extremity. (Scolaro J.A.)

Courtesy: Radiopaedia
Coronal and axial T1w T(F)SE images and a coronal STIR RF sequence.
With a characteristic appearance in a classic location, little differential exists. In cases where the lesion is heterogeneous in morphology or fluid-fluid levels are present, the possibilities include haemangioma, sarcoma, fat necrosis or a subcutaneous haematoma

 

Courtesy: Emad Almusa

Morel-Lavallée lesion shown on coronal STIR (image 1), T1 FS (image 2) and T(F)SE T2w (image 3) image. Note that the anatomic position lateral to tensor fascia lata, and the complex signal characteristics, which often include fluid-fluid levels (arrow)

Additional applications

  • muscular and tendon lesions are easily seen on US (see below under Fusion MRI-US in sport-related MSK injuries);
  • groin pain (see below under Differential Considerations);
  • detect the subtle trabecular disruption.

10.04 Differential considerations and examples in hip, knee and shoulder joints

Differential considerations in imaging regarding groin pain include the partial or complete muscle tears with rectus femoris being particularly vulnerable as it crosses two joints. Kicking sports are commonly concerned. Less commonly, a bone injury or fracture, a hernia, or even kidney stones might cause groin pain. Although testicle pain and groin pain are different, a testicle condition can sometimes cause pain that spreads to the groin area. An avulsion fracture (ligament or tendon pulled from the bone) or Bursitis (joint inflammation) can be the cause.
The hip joint is a ball and socket joint. The principle function of the hip is to enable weight bearing for movement. Impingement can arise at extremes of movement. Abnormal morphologies of the hip or increased level of activities can worsen the situation, resulting in frequent and often symptomatic impingement in the hip joint.

Unexpected causes of hip pain that may originate from other nearby structures such as the sacroiliac joints, pubic bones, or even the lower lumbar spine can be detected using a larger FOV.

Courtesy: Andreas Serner

Anatomical images of the rectus femoris. Image 1 shows an anatomical dissection of a 46-year-old male of the left proximal rectus femoris insertions. The direct tendon (PDT) attaches to the anterior inferior iliac spine (short arrows), and the indirect tendon (PIT) to the acetabular rim (long arrows). Image 2 shows an anterior view of the complete rectus femoris muscle removed from its attachments in image 1. Note the long free PIT (arrowhead). The distal extent of the intramuscular PIT is indicated with longer arrows. Image 3 shows a posterior view of the complete rectus femoris muscle. Note also the proximal extent of the posterior superficial tendon aponeurosis of the distal tendon (DT). FH = Femoral Head

Courtesy: Kal Parmar

When imaging complex groin pain, an MRI scan of the pelvis is requested, it is key to ask for symphyseal views which take oblique sections through the symphysis and thus any symphyseal fluid, irregularity and cystic change can be seen together with the adductor origins and pubic rami

Courtesy: L. Pesquer

Secondary cleft sign. Fat-suppressed T2w coronal MR image. Secondary cleft sign reflecting a hyperintense tendon tear at the tendon-bone junction

 

Courtesy: Brandon Davila

Osteoid osteomas present in patients aged 10-30 years and are therefore not uncommon in athletes. Most lesions are cortically-based, and consist of a central, dense nidus surrounded by reactive sclerosis and bone marrow oedema. MRI can diagnose this abnormality with high sensitivity and specificity, while avoiding the radiation of CT or nuclear medicine bone scans.

Courtesy: Emad Almusa

Osteoid osteoma in a patient suspected of having a labral tear. CT  (image 1), MR arthrogram (image 2) and STIR (image 3) images demonstrate nidus (arrows) surrounded by bone marrow oedema in the STIR image

 

There are many other causes of groin pain in athletes and it is important that clinicians and radiologists review all aspects of images made, not just the hip itself. There are additional findings not uncommonly seen within the FOV especially with MR examinations, which, although not necessarily etiologic for the patient’s presentation of groin pain, may still be relevant to their overall well-being. Such gynaecological findings are particularly common in young female athletes.

 

Coronal MR arthrogram (T1w with FatSat) showing bright lesion in pelvic midline (arrow) in 26-year-old athlete presenting with query labral tear. Subsequent pelvic ultrasound (image 2) demonstrates an ovarian lesion with fine internal echoes and increased through transmission, typical of an endometrioma

MRI images can show stress fractures or even bone bruises that a plain x-ray will usually miss. It can also detect the early findings of arthritis, even when the x-rays are normal, because it can show changes in the  cartilage and underlying bone.

An MRI exam is a good tool for evaluating the many sources of pain caused by sports that may surround joints, especially at the hip joint. There are several tendons that insert around the hip which can become inflamed or degenerated. Bursitis, usually located at the outside (lateral) part of the hip, can be painful. In addition, when there is a recent injury due to excessive athletic activity, muscles can become injured (known as a “muscle strain”). Furthermore, do not forget the cartilage lesions (discussed in chapter 8 of the MSK e-module).

Courtesy: C. Pretchprapa

Suprafoveal cartilage delamination and defect in patient with cam deformity. Coronal and axial oblique HR PDwFS (TR/TE, 2200/25) shows the full-thickness femoral cartilage fissure and ulceration (white arrows) and cam deformity (white arrowhead in image 2)

Courtesy: Steph Curry

Courtesy: T. Piontek

MRI of a knee 5 years after a simultaneous arthroscopic reconstruction of the ACL and the PCL with hamstring tendons showing a proper localisation and structure of grafts without knee subluxation

 

MRI is the preferred advanced imaging modality for the evaluation of symptomatic ACL graft reconstructions.

Courtesy: P.S. Chatra

Normal Reconstructed ACL: T2w sagittal image showing quadruple thickness hamstring graft (arrows) in isometric position with normal SI

 

Courtesy: Bencardino J.

Endobutton used for hamstring graft fixation in ACL reconstruction. Sagittal (image 1) and coronal (b) PDw T(F)SE MR images show an endobutton (arrows) affixing the graft at the proximal opening of the femoral tunnel

Tibial Stress Reaction

Courtesy: M.C. O’Dell

Grade 4b stress fracture in a 14-year-old female distance runner with knee pain. Coronal FS T2w MR image shows marrow oedema in the proximal tibial metaphysis. The horizontal hypointense line (arrow) in the lateral aspect of the proximal tibial metaphysis is consistent with stress fracture

 

Strong T1w and homogeneous fat suppression provides depiction of bone damage

An example of an Iliotibial Band (ITB) Syndrome:

The ITB runs down the outside of the leg and is a thickening of the normal fascia that surrounds the thigh.

The fascia is a thin membrane that connects or attaches every structure, muscle andinternal organs.

ITB attaches to the TFL (Tensor Fasciae Latae) at the front of the hip and to part of the gluteus maximus at the back of the hip.

The TFL goes down to the outside edge of the tibia and to the head of the fibula (the two bones which form the shin). It also attaches to the patella (kneecap). If there is any tightness or any problem with the TFL, the knee will also be affected.

ITB syndrome is the second most common injury in runners. ITBS is usually felt as a localised pain on the outside of the knee when the leg is bent. It is usually worse going up and down stairs and running downhill.

Courtesy: Radiology Blog

Multilobulated cystic areas in the lateral recess deep to the iliotibial band along with focal discontinuity in the tract with communicating fluid space superficial to the band. The images show thickening of the tibial insertion of iliotibial band on the gerdy tubercle and there is reduced space between the distal iliotibial tract and lateral femoral condyle. These findings suggest iliotibial band friction syndrome with an associated bursal cyst and possible discontinuity in the band

Labral Tear/ SLAP Tear
A SLAP tear is an injury to the labrum of the shoulder, which is the ring of cartilage that surrounds the socket of the shoulder joint.

The common symptoms of a SLAP tear are similar to many other shoulder problems. They include:

  • a sensation of locking, popping, catching, or grinding;
  • pain with movement of the shoulder or when holding the shoulder in specific positions;
  • pain when lifting objects, especially overhead;
  • decrease in shoulder strength;
  • a feeling that the shoulder is going to “pop out of joint”;
  • decreased range of motion;
  • pitchers may notice a decrease in their throw velocity, or the feeling of having a “dead arm” after pitching.

Courtesy: Dr Jurek

 

Courtesy: H. Barazi

3T: image 1: the MRI image shows absence of the long head biceps tendon at the level of the bicipital groove with no evidence of tendon dislocation, which suggests a complete tear of the tendon with distal retraction. Image 2 shows absence of the long head biceps tendon at the level of the bicipital groove with no evidence of tendon dislocation, which suggests a complete tear of the tendon with distal retraction

10.05 MR Arthograms

In chapter 3 of this MSK/Orthopaedic e-module, arthrograms are widely discussed: direct and in-direct MRI arthrograms are also indicated for sports medicine.

Arthrograms can be done in all joints ̶ the wrist, elbow, shoulder, hip, knee and ankle. Of course, different lesions are particular to certain sports. For example, a swimmer often has rotator cuff, labral-slap-tears or shoulder blade (scapular muscle) injuries.

MR or CT arthrography?

Conventional arthrography, Ultrasound is primarily taken over by CT and MRI arthrography. For intra-articular pathology MR arthrography is the imaging method of choice.

Intra-articular structures can be characterised as:

  • labrum;
  • articular cartilage;
  • ligamentum teres;
  • osseous structures.

CTA (CT arthrography) allows assessment of the cartilage surface and thickness, and can be used when MR is not available or contraindicated.

Note that CTA:

  • cannot assess purely chondral lesions;
  • gives a poor evaluation of the soft tissues;
  • exposes the patient to radiation.

MR arthrography has proved:

  • to have accuracies as high as 90% in the diagnosis of labral tears;
  • better delineation of labral tears than CTA;
  • no statistically significant difference in demonstration of articular cartilage abnormalities.

When making an advanced arthogram in sports-medicine, an anaesthetic agent (such as ropivacaine) is often injected, in addition to the contrast material.

If the patient has relief of pain immediately after the procedure this leads  the physician to an intra-articular cause for the pain.

After the injection, the patient can be asked to perform the activities that typically produce pain, in order to determine whether there is relief in the symptoms.

The agents injected during a hip arthrography include a mix of gadolinium (1:200 dilution), non-ionic iodinated contrast-material, normal saline and an anaesthetic agent (ropivicaine – which is considered safer than other local agents).

3D thin sliced isotropic images should be produced.Image 1: the bony cam lesion flattening the femoral head-neck junction, with associated bone marrow oedema is identified. In image 2 (same patient), the typical associated anterior-superior labral tear is seen in the MR arthrogram

Courtesy: E. Almusa
Image 1: coronal CT arthrogram demonstrates cartilage loss along the weight-bearing portion of the joint. Image 2: coronal MRI arthrogram in the same patient shows the cartilage loss, as well as the labral tear (white arrow).
Image 2: MR arthrogram showing cartilage loss and the labral tear (white arrow).
Labral tears are often seen together with FAI (FemoroAcetabular Impingement) and commonly affects individuals of 20 to 50 years of age. Pain is usually worsened by sitting or athletic activity, and a positive impingement test should form part of the clinical assessment. Plain films may show signs of cam or pincer impingement. If surgical intervention is considered, an MR arthrogram is indicated to demonstrate chondral wear and labral pathology

Courtesy: E. Almusa

 24-year-old female runner with pain. Coronal fluid sensitive RF sequence shows stress fracture of the femoral neck with surrounding oedema

Courtesy: E. Almusa

Differential considerations in imaging with respect to groin pain include the relatively common partial or complete muscle tears with rectus femoris being susceptible as it crosses two joints. Kicking sports are implicated, and the reflected (indirect) head is more commonly injured than the direct head.

10.06 Injury Prevention

Increasingly, teams of high-ranking sports clubs (such as the Lotto-Belisol WorldTour team) undertake their check of measurements of core stability and muscle strengthen (in their case at the radiology department of the CHC Clinique St-Joseph in Liège, Belgium). The Standard Liège football club have their tests in the Académie Robert Louis-Dreyfus and the Centre Cardiologique Orban.

Besides core stability and muscle strengthening, injury prevention focuses, on the stability of the neck, back, knees, pelvis and abdomen and the correct posture, depending on the sport.

 In sports medicine, MRI is becoming a valuable tool.

The pressure on medical and science teams to maintain professional players in top condition increases commensurately with the physical demands and the financial investments in the industry. This is why developing functional MRI, RF sequences and improving the spatial resolution is necessary.

Courtesy: Visions Special Magazine Toshiba Medical / Canon / Sports Medicine / Medical Testing at Lotto Belisol. Original: text: Brokken Y., photo Cor Vos / Imo Keizer

 

10.07 Fusion MRI-US in sport-related MSK injuries

MSK US (Ultrasound) is relatively cheap, portable and can be used to facilitate targeted injections. US can be performed immediately on the field if needed,  if a haematoma shows in injured soft tissue. However, the FOV is rather limited and so fusing MR-US is an ideal combination. An experienced sonographer with specific skills in MSK imaging can perform the fusion technology without difficulty.

US clearly shows problems in the superficial layers, and sometimes even more distinctly than MRI. MRI is better in cases of lower grade muscular injuries and deep muscle injuries with significant oedema and haematomas, bone diease, cartilage damage and marrow abnormalities of trabecular fractures: but it lacks the dynamic capablities of US. The combination of assessing the same structure or injury with both imaging modalities simultaneously will result in better clinical decisions.

Courtesy: Manuel Wong-On

20-year-old athlete with necrosis muscle from exercise induced rhabdomyolysis after a 100 km training session by bicycle. MRI T2w-US fusion 1 week after the training session on his quadriceps, note the necrosisi focus at the vastus medialis (Vm) of his right thigh, seen as a hyper intensity on T2w and a hyper echogenicity on the US scan. RF rectus femoris

 

Courtesy: Courtesy: Purohit N.B. and King L.J.

(a) Longitudinal and transverse views of the left gastrocnemius muscle in a female runner showing 5.5 cm myofascial separation tear consistent with a grade II injury. Complexity and stranding within the hypoechoic area represent a blood clot. Intact muscle fibres are seen on the transverse view. (b) Longitudinal and transverse views of the hamstring muscle in a footballer demonstrating moderately extensive hyperechoic change representing haemorrhage and oedema (white arrow) suggestive of a grade II injury. Contemporaneous MRI images of the same injury show a small discrete haematoma and muscle fibre retraction. (c) A longitudinal view of the hamstrings in a water skier with a corresponding MRI image. The white arrow demonstrates the proximal end of the retracted muscle stump consistent with a grade III injury

 

Publications:

. Evaluation of MRI-US Fusion Technology in Sports-Related Musculoskeletal Injuries (article in Advances in Therapy June 2015)

. (PDF) Evaluation of MRI-US Fusion Technology in Sports-Related Musculoskeletal Injuries. Available from: https://www.researchgate.net/publication/278850836_Evaluation_of_MRI-US_Fusion_Technology_in_Sports-Related_Musculoskeletal_Injuries.

 

Courtesy: M. Wong-On

Normal knee. Image 1: anterolateral view of the knee where the iliotibial band (arrows) insertion at the Gerdy’s tuberde (asterisk) is used to fuse both images. Note the band section has a good quality image in both MRI and US. Image 2: medial knee side shows a zoomed-out image in which the medial collateral ligament (MCL) (star) is used to fuse both images. By zooming in the image the MCL could be assessed by US with good resolution but gives limited FOV restricted to the medial side of the knee as we cannot see past bony structures, but zooming out in the fused image allows navigation and visualises the meniscus of the US image. F: femur, T: tibia

 

18-year-old football player with a scar in his rectus femoris (RF) intramuscular aponeurosis (star), T2w-US fusion image showed an enlargement of the tendon, S Sartorius

 

Courtesy: Manuel Wong-On

A 22-year-old synchro swimmer with serious pain in her right anterior elbow after heavy training. MRI showed a hyper SI on the deep muscular fibres on T2w, characteristic of delayed onset muscle soreness (DOMS) injury (star) in her right brachialis muscle (Br). Fusion image: obtained 24 hours after MRI acquisition; US image shows a little increase in the echogenicity in the same zone. Arrows: biceps tendon, H: humerus

US will continue to be used for monitoring the healing process and controlling haematoma, fibrosis, architecture repair etc. It is cheaper but not the best “return-to-play marker” decision.

 

10.08 NIRS (Near InfraRed Spectroscopy)

Another non-invasive technique to study the human muscle energetics in sports medicine is NIRS. NIR light (700-1000 nm) penetrates skin, subcutaneous fat and underlying muscle, and is either absorbed (by oxy- and deoxy-haemoglobin) or scattered within the tissue. NIRS is a non-invasive and relatively low-cost optical technique that is becoming a widely used instrument for measuring muscle O2 saturation and changes in haemoglobin volume. Muscle O2 saturation represents a dynamic balance between O2 supply and O2 consumption in the small vessels such as the capillary, arteriolar and venular bed. NIRS offers the advantage of being less restrictive than 31P-magnetic resonance spectroscopy regarding muscle performance and more comfortable and suitable for the monitoring, with high temporal resolution (up to 10 Hz), of multiple muscle groups. NIRS can objectively evaluate muscle oxidative metabolism in athletes and its modifications following potential therapeutic strategies and specific training programmes.

Courtesy: Nutte Teraphongphom

Image 1: NIR (Near InfraRed) light has the best penetration depth through soft-tissue image 2:  Light when entering a medium can be reflected, scattered and absorbed by molecules within the tissue (chromophores) or excite endogenously or exogenously-administered molecules to emit light at a different wavelength

 

10.09 Module Review

Early diagnosis and treatment can have important implications for athletes, thus allowing a quick return to play for the professional or elite amateur athlete.

High field MRI is a great diagnostic modality for the assessment of groin and joint pathology. In the athlete with symptoms that are not specific, conventional unenhanced MRI can evaluate the hip and pelvis for fracture, muscle or tendon injury, osteitis pubis (bone marrow oedema), sacroiliac joint abnormality or possible tumour. If intra-articular pathology is suspected, an intra-articular arthrogram can be made. This shows e.g. in the hip, the acetabular labrum, ligamentum teres and cartilage. Spatial resolution should be high, which makes the detection of subtle labral and cartilage pathology possible.

There will be new indications focusing on areas such as:
• how fibrosis in previous injury has affected the recovery process, seen on T1w images;
• how elastography could help as a marker of flexibility;
• how we can see changes in the architecture remodeling using DTI;
• how the healing process by T2w mapping is changing in terms of recruitment of muscles.

The reference standard of imaging muscle injuries of e.g. in the hip and thigh is MRI using fluid sensitive and T1w RF sequences. Characteristic findings are oedema, haematoma, and partial or complete muscles tears. Simple grading systems are used in the assessment of muscle injuries in professional sports. Detailed imaging features such longitudinal length and volume of the muscle tear and involvement of the intramuscular component of the tendon have recently shown a significant impact on prognosis. These features should be precisely described, and a close collaboration with the team doctor is very helpful.

 

Fusion technology is an interesting tool in terms of MSK imaging. The use of 3D MRI RF sequences optimises US for ‘‘navigating’’ within the MRI and US at the same time; 3D MRI protocols should be applied for those who use the fusion technology.

Besides MRI, MRS and US, other powerful non-invasive methods are emerging for the study of human muscle energetics in sports medicine. NIRS (Near InfraRed Spectroscopy) is one of them. NIR light (700-1000 nm) penetrates the skin, subcutaneous fat and underlying muscle, and is either absorbed (by oxy- and deoxy-haemoglobin) or scattered within the tissue. NIRS is less limiting than 31P MRS regarding muscle performance, easier and more suitable for monitoring, with high temporal resolution (up to 10 Hz), of multiple muscle groups.

 

Athletes may not know or remember the type of injury they had. Especially for athletes who travel, their documentation can be incomplete or they may need a sporting medical certificate. A solution can be to establish an electronic database or the athlete carries his/her own “medical passport”.

Courtesy:  europataichi.faemc

 

More is coming and the future will probably include PET (Positron-Emission Tomography) to better distinguish functional and metabolic muscle changes and the relation to pre-and post-muscle injuries, including the recovery process.

 

Additionnel publications :

Guermazi A. et al. (2017) Imaging of muscle injuries in sports medicine: sports imaging series. Radiology 285(3): 1063.

Mueller-Wohlfahrt H.W. et al. (2013) Terminology and classification of muscle injuries in sport: The Munich consensus statement. Br J Sports Med 47(6): 342-50.

Pollock N. et al. (2014) British athletics muscle injury classification: a new grading system. Br J Sports Med 48(18): 1347-51.

Valle X. et al. (2017) Muscle injuries in sports: a new evidence-informed and expert consensus-based classification with clinical application. Sports Med 47(7): 1241-53.

Yamada A.F. et al. (2017) Diagnostic imaging of muscle injuries in sports medicine: new concepts and radiological approach. Curr Radiol Rep 5: 27.

Brukner P. & Khan K., Clinical Sports in Medicine.

Vanhoenacker F.M.,Maas M. &Gielen J.L., Imaging of Orthopaedic Sports Injuries.

Jenkins Dr P, Sport Injuries

 

 

LEARNING – EVALUATION MOMENT:      

After this introduction Sports medicine in MSK and at the end of the module you should be able:    

                       

  • To understand the acronyms and abbreviations in this part of the module.
  • To have an in depth knowledge of the behaviour, contrast and special effects of the different RF sequences and methods used in imaging sports medicine .
  • To understand the indicationand techniques used in Imaging, MR and MRS sports medicine.
  • To describe various applications for the use of imaging in sports medicine in MSK.

At the end of this module you should have the skills to design imaging protocols for MRI exams in sports medicine, choosing the best method and contrast  discussed in this part of the module.

 

BEFORE YOU GO TO THE NEXT PORTION: TAKE THE QUIZ

Answer the questions and choose a statement so you can jump to the LAST chapter!

 

All done? Let me know what you think or have any questions! wilma@emric.fr Thanks!