Whole-Body MRI

What It Shows

• Bone marrow infiltration — diffuse or focal disease in myeloma, lymphoma, leukaemia
• Skeletal metastases — earlier detection than bone scan, superior to CT for marrow disease
• Soft-tissue metastases, lymph nodes, and peritoneal disease
• Whole-body DWI map — highlights all sites of cellular tumour activity simultaneously
• Oligometastatic cancer staging — identifies number and location of all metastatic sites
• Spinal cord compression — full spinal assessment in one study
• Response to systemic therapy — marrow reconversion after myeloma treatment

How It Works

The patient lies supine on an MRI table. Multiple overlapping body 'stations' are acquired sequentially (skull base, neck/chest, abdomen, pelvis, thighs, legs) using standardised sequences: T1-weighted (anatomy), STIR/T2-fat-suppressed (oedema and lesions), and DWI (cellular density). The table moves between stations. Total acquisition time is 45–90 minutes. Images from all stations are automatically stitched together to form a single head-to-toe composite. A radiologist reviews the coronal T1, STIR, and DWI maps together.

• Myeloma staging and response assessment (IMWG criteria)
• Prostate cancer oligometastatic staging for metastasis-directed therapy planning
• Lymphoma bone marrow assessment (replacing trephine biopsy in some guidelines)
• Paediatric cancer staging where radiation minimisation is paramount
• Any staging scenario where radiation-free whole-body assessment is preferred

WB-MRI evidence is strongest in myeloma. The MYELOMA-XI trial demonstrated WB-MRI superior to skeletal survey for detecting bone disease. NICE (NG35, 2016) recommended WB-MRI as the preferred imaging for myeloma staging — replacing skeletal surveys. A 2020 meta-analysis showed WB-MRI sensitivity 91%, specificity 92% for myeloma bone lesions vs 57%, 97% for skeletal survey. In oligometastatic prostate cancer, WB-MRI detects 24% more lesions than CT + bone scan (STOMP trial pre-imaging data). Evidence for WB-MRI in other cancer types is growing but not yet at guideline-level in most indications. Main limitation is scan duration (45–90 min) and availability.

Preparation & What to Expect

Remove all metal objects. Declare implants and metallic devices. No fasting required for standard WB-MRI without contrast. Wear comfortable clothing. Be prepared for 60–90 minutes inside the scanner — some centres offer headphones and music. Patients must be able to lie still — sedation rarely needed.

• Long scan duration — 45–90 min is uncomfortable for patients with pain or poor mobility
• Standard MRI contraindications apply (pacemakers, certain implants, severe claustrophobia)
• Limited availability outside specialist cancer centres
• Not optimal for lung parenchyma — CT remains superior for pulmonary metastases
• DWI can show false positives from inflammatory nodes, bowel, and physiological marrow activity

• No radiation — safe for repeated use, appropriate for young patients and those requiring long-term monitoring
• Standard MRI safety contraindications apply — metal screening mandatory
• Requires specialist reporting — WB-MRI DWI interpretation requires specific training