Imaging in Sports

Injury

By Dr. Rajal Sukhiyaji

CONTENTS IntroductionRole of imagingRisks of over imagingThe travelling athleteImaging ModalitiesSafety, Availability and

economic aspectsReferences

Imaging in Medical field Importance of imaging

technique Doubt about the Diagnosis Accurate assessment of injury Helpful to provide the athlete with visual

evidence that a significant injury is present

In cases where conservative management is indicated

Risks of over imaging

No direct relation between clinical symptoms and imaging findings. The diagnosis is already established and

imaging has already been carried out. Repeat studies often lead to confusion in the

mind of the athlete and coach.

Non-significant abnormalities.

Different reports

The Travelling athlete

• Their documentation may be incomplete.• Athlete may not know or remember, which type

of injury they had.

3 options :-• The athlete carries his/her own ‘medical

passport’.• The injuries are registered in an electronic

database.• The information is sent from the previous doctor

to the current doctor by internet or by fax.

Imaging Modalities

• Plain Radiography and Conventional Arthrography

• Ultrasound• Multidetector Spiral CT Scan

– Technique– CT Arthrography

• Magnetic Resonance Imaging– Technique– Direct and Indirect Arthrography

Choice Of Imaging Modalities

Plain Radiography and Conventional Arthrography

Radiographs - diagnostic images needed for the evaluation of sports injuries.

The presence of loose bodies or degenerative joint changes can easily be assessed with plain radiography.

Oblique views may be helpful Stress views may provide indirect

evidence of ligamentous injury.

To confirm the results after internal or external fixation with reduction of dislocations and alignment of displaced fracture fragments

For monitoring the progress of fracture healing with callus formation

Detection of soft tissue calcification after severe muscle trauma

The lack of soft tissue contrast-resolution When complications of the healing process

occur, such as infection or avascular necrosis, the role of plain radiography may be limited and other imaging techniques, such as bone scintigraphy and/or MRI, may be useful for confirming the diagnosis.

Conventional arthrography

The plain film shows

the fractured schaphoid

bone

• Ultrasound (US) plays a major role in sports traumatology, helping the clinician to decide whether the athlete should or should not return to training and competition.

• US keeps its leading edge when dealing with muscle pathology.

• High-frequency (13.5 MHz) probes are used to perform musculoskeletal US examinations.

• Transverse and longitudinal slices are mandatory.

• Dynamic US study may be very helpful.

• US palpation is a very valuable tool.• To avoid artefacts or pitfalls,

comparison with the contralateral side is necessary.

Low cost Availability at short notice Ease of examination Short examination times Lack of radiation exposure

The recent addition of color-power Doppler imaging to US has allowed for

the non-invasive study of blood flow and vascularity within anatomic structures

and lesions.

US provides image guidance for interventional procedures such

as,

Drainage of fluid collections

Drainage of Cysts

Sclerosis of neovascularity in painful chronic tendinosis

Limited depth of penetration and the small, static scan field

If the structure to be visualized is large (e.g., large intramuscular hematoma) or deeply localized (e.g., hip joint)o Extended field of view ultrasonography

(EFOVS) Other disadvantages of ultrasound include

o Operator dependencyo Less graphic imageso Selective and often incomprehensible

documentation and o The inability to penetrate osseous structures

Ultrasound image showing a rotator cuff tear. Afull thickness tear of the supraspinatus tendon

(between the cursors, thick arrow) is shown, where the

tendon traverses the humeral head (thin arrows).

Multidetector Spiral CT Scan

CT imaging, is a valuable imaging tool for the evaluation of all kinds of sports injuries.

Very fast image acquisition times of large volumes with submillimeter section thickness have become the norm.

It is an effective method of documenting injuries particularly in complex bony structures.

Slice thickness : 0.75mm – 1mm

Rotating X-ray tube Computer then processes the

data Technical advances

• All reconstruction methods offer a more effective display of complex anatomic and pathologic structures.

• It may be helpful for the assessment of comminuted fractures, improving visualization of the fracture’s extent and location, shape and position of the fracture fragments and the condition of articular surfaces.

CT Arthrography Intra-articular injection of iodinated contrast

material mixed with 1 ml of a 0.1% solution of epinephrine is performed under fluoroscopic observation.

The volume of contrast medium injected depends on which joint is studied:o Shoulder: 10–15 ml; o Wrist: 5 ml; o Hip: 10 ml; o Knee: 20 ml; o Ankle: 6–12 ml

After injection of contrast material, patients are asked to perform full-range mobilisation of the joint.

Anteroposterior, lateral and oblique views are routinely obtained to image the entire articular cavity.

Subsequently, multidetector CT is performed.

Advantages of CTA The major advantage of CTA for the

assessment of the cartilage is the excellent conspicuity of focal morphologic cartilage lesions.

Other potential advantages of spiral CTA,o The short examination time, o The availability at short notice (short

waiting list) o Limited degree of imaging artefacts

Its invasiveness,

Possible allergic

reaction, Use of ionizing

radiation Poor soft tissue

contrast resolution.

Another major

limitation of CTA

imaging of the cartilage

is its complete

insensitivity to

alterations of the deep

layers of the cartilage.

CT image shows in

3-dimensions the bony morphology

in a case of anterior hip

impingement.

Equipment and techniques for MRI vary widely, and although it is generally accepted that high

field strength magnets provide the highest quality images, there

has been considerable advancement in the technology of low field strength systems

over the past few years, greatly improving their image quality

A complete MR examination requires that images be obtained in the axial, coronal and sagittal planes.

Excessive rotation of a limb, inappropriate positioning of imaging planes may result in images which are difficult to interpret.

Spin echo(SE), gradient echo(GRE) and inversion recovery(IR) sequences

T1- weighted, T2- weighted, proton density and short T1 inversion recovery(STIR) sequences

Fat- suppressed and fat- saturated sequences

The musculoskeletal system, especially in the extremities, is not influenced by motion, and, as a consequence, motion artefacts are rare.

Contrast-enhanced MR studies lead to a prolonged examination time and high costs, and therefore, the use of intravenous contrast agents is not indicated when evaluating a sports lesion.

Recently,

Diffusion Tensor Imaging (DTI) T2-mapping, Spectroscopy, Blood-oxygenation- level-dependent

(BOLD) imaging, and Molecular imaging

These new techniques hold the promise for a more complete and functional

examination of the musculoskeletal system.

• It is not always being well accepted by patients, of being incompatible with dynamic manoeuvres and of not always being possible in emergency conditions.

• It provides the evaluation of an entire anatomical area – bone structures included – but is only good for the study of a limited part of the skeleton.

Direct and Indirect Arthrography

MR arthrography is a technique which is mainly used in the shoulder, wrist, ankle, knee and hip joint.

Two different techniques are described – oDirect MR arthrographyo Indirect MR arthrography

Coronal plane MRI image diagnoses a tear of the medial

meniscus (long arrow), with a

meniscal fragment displaced within the joint (dotted arrow).

Note the normal lateral meniscus

(short arrow).

Safety, Availability and Economic Aspects

Ionizing radiation is harmful and there is no safe lower threshold of radiation

Examinations on children

Therefore, when clinically appropriate, the alternative use of safer nonionizing techniques (such as ultrasound and MRI) or of low dose radiography/CT techniques must always be considered

MRI findings may have a significant impact on diagnosis and treatment planning.

Appropriate selection of patients will probably yield similar results in other anatomic locations.

The advancements in MRI technology may expand the range of usefulness of this modality, leading to even greater utilization of MR imaging in patients with sports injuries, and, eventually, to reduced costs and greater availability.

Neurological investigationo Electromyography oNerve conduction studies oNeuropsychological testing

Muscle assessmentoCompartment pressure testing

Cardiovascular investigationo Electrocardiographyo Stress electrocardiographyo Echocardiography

Respiratory investigation o Pulmonary function tests

Clinical Sports Medicine, Peter Brukner & Karim Khan

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

Sports Injuries : the Role of Imaging in Diagnosis and Treatment, Dr Paul Jenkins, MA MD FRCP, Medical Director

Diagnostic Imaging of Sports Injuries, Matthew D. Richardson, D.C., DACBR, Director of Clinical Radiology, Palmer Florida Campus.