Musculoskeletal Imaging What to order? Brian Cole, MD

my background: 1994 University of Illinois 1998 MD University of Illinois College of Medicine 1999-2003 Diagnostic Radiology Mayo Clinic 2004 Fellowship Musculoskeletal Radiology, Mayo Clinic 2005-present

What is the best imaging test? Plain film radiographs MRI CT US Bone Scan MR Arthrography CT Arthrography

What is the cause of musculoskeletal pain?

Clinical Evaluation Primary Care Orthopedics

Shoulder Pain: Patient Information Form

Tailored to individual joint Tailored to individual patient

Today s Objectives Keep it simple Musculoskeletal MRI basics Utility, terminology A few rules of thumb for what imaging study to order interesting cases

You have many imaging options for evaluation of bone/joint complaints.

What about radiography (X-rays)?

1901 Nobel Prize in Medicine German physicist Wilhelm Roentgen

What about radiography (X-rays)?

Imaging should be tailored to the joint. In general, plain film evaluation should precede CT, MR, arthrography, and nuclear medicine studies

Acute post-traumatic shoulder pain: plain films for fracture or dislocation

Acute post-traumatic shoulder pain: CT for further evaluation of known fracture

Acute post-traumatic shoulder pain & negative plain films: consider MRI.

Acute post-traumatic shoulder pain & negative plain films: fracture.

Acute post-traumatic shoulder pain & negative plain films: consider MRI.

Acute post-traumatic shoulder pain & negative plain films: rotator cuff tear.

Chronic shoulder pain & negative plain films: consider MRI (+/- arthrogram): labral tear.

28 year old with shoulder pain

28 year old with shoulder pain Labral tear

In general radiographs prior to MRI. 58 y/o woman with pain following a fall.

Get radiographs prior to MRI.

radiographs prior to MRI. Fibular fracture.

radiographs prior to MRI.

radiographs prior to MRI. Cuboid (bone) contusion.

Radiographs prior to MRI. Then

MRI

This is all I know about MR physics. Slide 1 of 2.

This is all I know about MR physics. Slide 2 of 2.

MRI sequences T1 (short TR, short TE) T2 (long TR, long TE) Proton Density (long TR, short TE) STIR (Inversion Recovery)

MRI sequences T1 Fundamental sequence Evaluate fat Soft tissue planes Bone marrow Fat is bright Fluid is dark T2 Fat saturation all fat is saturated out (made dark) Evaluate fluid Soft tissue edema Fluid is bright Everything else is dark

MRI sequences Proton Density Intermediate sequence Short TE Fluid sensitive like T2 STIR (inversion recovery IR) Fluid sensitive like turbocharged T2 But less resolution Not susceptible to field inhomogeneity - - pure fat saturation throughout

imaging planes axial coronal sagittal

T1 sagittal Bone marrow Tissue planes

Abnormal marrow

64 y/o woman with lung cancer

39 y/o man with hip pain

Case: 38 y/o left knee blunt injury pain medial and lateral

MRI Coronal T1 normal Lateral tibial injury

Tibial fracture Cor T2 fat sat Cor T1

MRI Axial T2 fat sat

38 y/o male injured playing softball, sliding into 2 nd base

Chronic persistent pain after injury repeat films? CT? MRI? Bone Scan?

Chronic persistent pain after injury repeat films? CT? MRI Bone Scan?

Talar Fracture

What about computed tomography (CT)?

CT - characterize complex fractures

CT is great for assessing complex fractures. 12 y/o girl with a trampoline injury.

CT is great for assessing complex fractures. Tri-plane injury.

Acute post-traumatic knee pain: plain films and CT for fracture.

Acute post-traumatic knee pain: plain films and CT for complex fracture.

CT - characterize complex fractures - evaluate fracture healing

Scaphoid fracture healing

CT scaphoid fractures -Memarsadeghi M, Breitenseher MJ, Schaefer-prokop C et-al. Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience. Radiology. 2006;240 (1): 169-76. -

Scaphoid fractures CT High sensitivity/specificity Less for trabecular inj Staging Additional carpal injuries Bone union MRI Can detect completely undisplaced fractures Soft tissues/ligaments AVN

CT Arthrogram

CT Arthrography WRIST Intrinsic ligaments Extrinsic ligaments Capsule/synovium Cartilage Bone TFCC

CT Arthrography technique Fluoroscopic guided injection Radiocarpal compartment 1:2 solution omni/saline 4-6 ml contrast CT bone algorithm multireformatted

Fracture healing cartilage ligaments TFCC

CT Arthrogram

- characterize complex fractures - evaluate fracture healing - negative films with high clinical suspicion for fracture* -scaphoid -midfoot -elbow

CT is not good for all fractures. 80 year old with hip pain and inability to walk.

CT is not good for all fractures. Isolated greater trochanter fracture.

MRI for occult hip fx - Frihagen F, Nordsletten L, Tariq R, et al. MRI diagnosis of occult hip fractures. Acta Orthop. 2005;76:524-530. - Verbeeten KM, Hermann KL, Hasselqvist M, et al. The advantages of MRI in the detection of occult hip fractures. Eur Radiol. 2005;15:165-169.

MR is better for some fractures.

MR is better for some fractures. Intertrochanteric fracture.

MR is better than CT for soft tissue injuries. Intertrochanteric fracture.

Acute post-traumatic hip pain and negative plain films: CT or MR?

Acute post-traumatic hip pain and negative plain films: fracture.

Acute post-traumatic hip pain and negative plain films: muscle tear.

CT for known complex fractures, MRI for injury with normal plain films

What about ultrasound (US)?

US offers a less costly method of soft tissue evaluation. ~ technologist experience

What about ultrasound (US)? Definite potential for some soft tissue injuries, particularly in the shoulder.

The End