Indications - MRI vs. CT
Download this| Clinical Problem: Brain | Preferred Study | Contrast | Comments |
|---|---|---|---|
| Headache, acute | CT | No | Bone windows replace skull series |
| Headache, chronic | MR | Yes | |
| CVA | MR/CT | No | CT if patient uncooperative |
| Acute Bleed | CT > MR | No | MR may show source such as AVM or aneurysm |
| Brain Tumor | MR | Yes | CT better for tumor calcification |
| Seizure | MR | Yes | |
| CNS infection, abscess, meningitis | MR | Yes | |
| AIDS | MR | Yes | |
| Dementia | MR > CT | No | MR superior evaluation of white matter changes |
| Neurodegenerative disorder | MR | No | Parkinson’s disease, etc. |
| Subdural hematoma | CT | No | MR detects smaller nonsurgical SDH |
| MS | MR | Yes | |
| Posteria fossa, brainstem lesion | MR | Yes | MR far superior in this region |
| Acoustic neuroma | MR | Yes | CT not sufficiently accurate |
| Pituitary tumor | MR | Yes | MR far superior in this region |
| Aneurysm | MR & MRA | No | |
| Sinus venous thrombosis | MR & MRV | No | |
| Trauma | CT | No |
| Clinical Problem: Neck, Skull Base, Orbit | Preferred Study | Contrast | Comments |
|---|---|---|---|
| Sinuses | CT | No | |
| Neck mass | CT >> MR | Yes | MR only in special situations |
| Skull base | CT | No | |
| Nasopharynx | CT | Yes | |
| Optic nerves/orbits | MR >> CT | Yes | CT – for calcification |
| Cavernous sinus | MR | Yes | |
| Cranial nerve dysfunction | MR | Yes | |
| Trauma | CT | No | Maxillofacial CT replaces plain films |
| Brachial Plexus | MR | Yes |
***above studies read by neuroradiologists
| Clinical Problem: Musculoskeletal | Preferred Study | Contrast | Comments |
|---|---|---|---|
| Avascular necrosis | MR | No | Bone scan if MRI contraindicated |
| Hip pain-negative x-rays | MR | No | Best to look for occult hip fracture if x-rays are negative |
| Metastasis/Myeloma | MR | Yes | |
| Osteomyelitis/Cellulitis | MR | Yes | |
| Knee: Meniscal tear/cysts; ligamentous injury; tendon injury; bone contusion; fracture; osteochrondritis dissecans; chrondromalacia | MR | No | |
| Shoulder: rotator cuff tear; tendinitis; labral abnormality; bone injury; contusion | MR | No | MR arthrogram if labral tear suspected |
| Soft tissue mass | MR | Yes | Specific for lipoma-Detects extent/neurovascular involvement of non-lipomatous masses |
| Bone tumor | MR | Yes | Evaluates extent/neurovascular involvement. CT can be good for evaluating matrix type. |
| Fracture |
MR or CT see comments |
No | MRI if radiographically occult fracture is suspected. CT if fracture is seen on x-ray and position or alignment is to be addressed. CT for avulsion or small cortical fracture. |
| Bone bruise | MR | No | |
| Loose bodies | MR or CT | No | Patient may need arthrography followed by CT or MRI. MRI can detect loose bodies in the presence of effusion. CT can detect ossified loose bodies. |
***above studies read by musculoskeletal fellowship trained radiologists
|
Clinical Problem: Spine |
Preferred Study | Contrast | Comments |
|---|---|---|---|
| Herniated disc, cervical or thoracic | MR | NO | Value of contrast not well known |
| Lumbar herniated disc | MR >> CT | Yes, if previous surgery | Contrast distinguishes between scar and disc after surgery |
| Stenosis | MR >>> CT | No | |
| Discitis | MR | Yes | |
| Metastasis, epidural tumor | MR | Yes | MR also superior to myelography |
|
Compression fracture, possible tumor |
MR | Yes | MR allows evaluation of bone marrow |
| Cord disease | MR | Yes | Demyelination – syrinx |
| Cord tumor | MR | Yes |
