Section 2
EVALUATION OF THE INJURED ATHLETE
18 DIAGNOSTIC IMAGING
Leanne L Seeger, MD, FACR
Kambiz Motamedi, MDINTRODUCTION
- There are several modalities available for the imaging
evaluation of sports injuries. The strengths and weak-
nesses of each modality, along with their specific indi-
cations are discussed in this chapter. - The choice of the imaging modality depends on sev-
eral factors, including the chronicity of the symptoms,
the suspected pathology, and potential treatment alter-
natives.
IMAGING MODALITIES
- Imaging tools that are commonly available are plain
radiography (with or without applied stress), conven-
tional arthrography, magnetic resonance imaging
(MRI), which may be combined with arthrography
(referred to as MRA), computed tomography(CT),
which may be combined with arthrography, ultra-
sonography, and radionuclide bone scans.
MODALITY STRENGTHS AND
WEAKNESSES
- Plain radiographyis widely available, relatively inex-
pensive, and provides excellent detail of bony struc-
tures and soft tissue calcifications. Even though soft
tissue resolution has slightly improved with digital
radiography (at the cost of loosing some of fine bone
details), the ability of radiography to depict soft tissue
pathology remains inferior to cross sectional imaging
(MRI, CT, and ultrasound).- Stress radiography (e.g., varusor valgus) reveals
abnormal laxity of joints and can indirectly diagnose
soft tissue injury. Stress must be applied by the refer-
ring physician. Disadvantages include availability of
the physician, radiation exposure, and subjectivity of
the amount of stress needed. In some cases, it may
exacerbate underlying pathology. - Conventional arthrographydelineates the synovial
space and intra-articular structures by joint disten-
tion. Although invasive, there are few inherent risks.
Arthrography requires patient preparation and coop-
eration, informed consent and the availability of a
radiologist. When arthrography is combined with
MRI or CT, coordination is needed for scheduling
scanner time to immediately follow the procedure.
Arthrography may be contraindicated in patients with
coagulopathy. - MRIprovides unparalled soft tissue and bone marrow
contrast. With acute or subacute injuries, soft tissue or
marrow edema is seen. With chronic injuries, struc-
tural abnormalities may be seen. It is of limited value
for evaluating bone cortex and soft tissue calcifica-
tion. There are several relative and absolute con-
traindications to MRI, including claustrophobia,
cardiac pacemakers, and certain kinds of neurosurgi-
cal aneurismal clips, and inner ear implants. Because
of the popularity of MRI, there may be a prolonged
wait time for obtaining an examination. - CTis superior to other modalities for fine bone detail,
and is an important tool for depicting the anatomy of
complex fractures. Three-dimensional CT reforma-
tions are extremely useful in the management of
trauma patients. This is especially true with the newer
generation (multislice) scanners that significantly
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