Shoulder Imaging
What shoulder imaging do I need before seeing Dr Herald?
Where possible, it’s always a good idea to bring recent imaging with you before you come to your first consultation with Dr Herald – which means treatment can commence sooner rather than needing a second consultation for him to review the imaging. Here are the different types of imaging and situations when they may be used.
X-RAY
PROS
– X-rays are good for shoulder arthritis as they show bone on bone. They will also show a small burn spur, loose bony bodies and detect fractures.
– They can be done standing upright, showing the effect of gravity on your joint.
CONS
– X-rays do not show the soft tissues of your shoulder like the rotator cuff, so a plain X-ray will show the shoulder as normal even when there may be an issue with the soft tissue.
DETECTION
– X-rays can be useful to detect many fractures (but not the more subtle ones such as the glenoid rim).
– They can also detect bone-on-bone arthritis and bone spurs, dislocation, separation, bursitis, and impingement syndrome and fractures.
CT SCAN
PROS
– Scans are like 3 dimensional X Rays so they are good for fracture orientation.
– The upside of a CT scan is that it is quiet, unlike an MRI which is not ideal for people who may be claustrophobic, highly anxious or don’t like the loud noise of the MRI scanner.
– CT scanning is generally faster than MRI as well and less expensive.
– Generally speaking, a CT scan may be good for a rapid “general” picture, say a head scan after an accident.
– An MRI tends to provide a more “detailed” picture and is ideal for intricate soft tissue injury pictures.
CONS
– The downside of a CT scan is that there is some radiation and the view of soft tissues is not as detailed as an MRI which uses radio waves and magnets to view the body.
DETECTION
– CT scans can be useful to detect bone alignment and fracture alignment, soft tissue injuries such as rotator care, trauma injuries, fractures and dislocation, and post-surgically where metallic hardware has been used.
– They can also pick up bleeding issues or blood clots.
– CT scan is the second choice for soft tissue shoulder injuries when an MRI is contraindicated (when the patient has a pacemaker for instance, metallic implants or MR incompatible prosthetic heart valves, claustrophobia or severe obesity).
ULTRASOUND
PROS
– An ultrasound has the advantage that it can assess the shoulder as it moves.
– This may be useful in situations such as mechanical subacromial impingement which happens when the patient lifts their hands above the head.
– Other situations where ultrasound has advantages over MRI include evaluation of soft tissue foreign bodies, soft tissues near hardware, abnormalities that necessitate a specific extremity dynamic manoeuvre or position to provide the diagnosis, and for guided procedures.
CONS
– An ultrasound is generally less superior to the MRI for labrum, bone marrow and deep soft tissues e.g. a suspicion of a labral tear would make MRI the first choice, as would a suspicion of cancer or cartilage loss.
DETECTION
– Ultrasound can be used to detect rotator cuff tear when MRI scans cannot be used due to hardware or if the patient has claustrophobia.
– The experience of the operator also makes a difference here.
– It can also detect bursitis, evaluate hardware performance after a shoulder implant, and be useful for conditions where movement is required for a diagnosis such as biceps long head instability.
MRI
PROS
– The upside of the MRI is that there is no radiation, and this form of imaging provides the most detailed view of the inside of the body.
CONS
– The downside of the MRI is that it is more expensive, and occasionally patients complain of feeling hot during the procedure.
– Some patients also feel extremely claustrophobic and cannot go through with the MRI once the loud noise starts, so these patients may want to ask their GP or Dr Herald about sedatives before their MRI shoulder scan.
DETECTION
– MRI is generally considered the “gold standard” of shoulder imaging.
– MRI can be used to detect stress fractures up to two weeks earlier than an X-ray can.
– An MRI can also help evaluate joint abnormalities caused by torn repetitive injuries such as torn cartilage, ligaments or a rotator cuff tear. The sensitivity for detecting a rotator cuff tear is about 90% for an MRI in the non-arthritic shoulder.
– MRI can also pick up disk abnormalities in the spine and neck (often shoulder pain is referred neck pain).
– An MRI may also pick up bone infections, and tumours of both the bones and the soft tissues.
– It is also the imaging test of choice for articular cartilage, bone marrow and most ligament abnormalities.
BONE SCAN
– Occasionally Dr Herald may also order a bone scan, which can be a useful adjunct in some types of shoulder arthritis and to establish a diagnosis of Complex Regional Pain Syndrome (CRPS), which typically affects an arm or leg and develops after an injury, surgery, stroke or heart attack. With this condition the severity of pain is out of proportion to the initial injury. It usually occurs in the shoulder and hand (but can also occur in the leg and foot).
PROS
– Recent research shows that bone scans are particularly effective (about 87% effective) in diagnosing Complex Regional Pain Syndrome*
CONS
– Despite the effectiveness of bone scans, there is currently no one definitive test to diagnose CRPS, which is based on an exam and medical history, as well as a bone scan, and often other imaging such as X-ray or MRI.
DETECTION
– Outside of CRPS, bone scans can also be used to detect other shoulder conditions such as arthritis, bone tumors, Paget’s Disease (a bone disorder in older people) and avascular necrosis (death of bone tissue due to loss of blood supply in the bones.
– A bone scan is different to a bone density test (DEXA) which evaluates thinning of the bones and bone strength.
Source: Triple Phase Bone Scan sensitivity of 87%; Journal of Nuclear Medicine 2017
CRPS: A review of diagnostic tools.