Whole-Body MRI — metastatic disease and cancer predisposition surveillance
Skull vertex to mid-thigh or to the feet, depending on the primary and the surveillance programme.
Typical, not policy
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Bone-dominant metastatic disease, particularly advanced prostate cancer, for staging and response assessment.
- Surveillance in cancer predisposition syndromes such as Li-Fraumeni, where cumulative radiation from repeated CT is unacceptable.
- Staging where bone marrow disease is suspected and radionuclide imaging is equivocal.
- Assessment of skeletal disease burden where a structured whole-body reporting system is used.
- Paediatric and young adult surveillance where radiation avoidance is the driver.
Technique
- Axial diffusion across all stations with paired low and high b values and ADC maps.
- T1 Dixon anatomical stations with fat and water images; sagittal spine sequences.
- Additional targeted sequences over an organ of interest where the primary demands it.
- Response assessment relies on reproducing station geometry and b values exactly between timepoints.
Where it goes wrong
- Protocol drift between timepoints, which is the dominant failure mode in serial whole-body imaging.
- Susceptibility artefact at metal implants and at air-tissue interfaces creating apparent diffusion lesions.
- Bowel and bladder signal on high b-value projections obscuring pelvic bone.
- Treatment-related marrow changes, including granulocyte colony-stimulating factor effect, producing diffuse marrow signal misread as progression.
- Coverage inadequate for the known distribution of the primary.
Clinical questions that reach this study
Contrast
None
- Unenhanced diffusion-based protocol. Contrast is added only where a specific soft-tissue question requires it.
Acquisition
- Breathing
- Free breathing for diffusion; breath-hold or navigator for thoracoabdominal anatomical stations.
- Reconstruction
- Composed whole-body coronal images, inverted high b-value projections and ADC maps.
- Preparation
- This is a long study, typically 45-60 minutes; assess tolerance, claustrophobia and analgesia needs at vetting rather than on the day. Supply the paraprotein or PSA trajectory and prior whole-body imaging so the same stations and b-values are matched for comparison. Intravenous contrast is not routinely part of the diffusion-based protocols and should not be assumed.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- MR safety screening for implants and foreign bodies· radiographer at scan