Whole-body MRI

What it does

Whole-body MRI reads skeleton-wide studies acquired in several stations with T1 Dixon, STIR or T2 and diffusion-weighted imaging. These are long specialist reads: hundreds of slices per sequence, diffuse and focal disease side by side, and response judged region by region against a previous study.

The run reads the bone marrow in two disease frames. For multiple myeloma it separates focal lesions from diffuse marrow infiltration, counts the focal lesions and, with a prior, assigns a response category. For metastatic prostate cancer it maps the bone metastasis burden region by region and, with a prior, classifies the response of each region. Dixon fat and water images and the ADC map are read together, since fat fraction and diffusion each show a different side of marrow disease.

Intended use

Decision support for physicians reporting whole-body MRI in haematology and oncology pathways: a structured, region-based read that follows the reporting system of each disease and keeps lesion counts and response categories consistent between visits. Every finding comes with its location and evidence.

Who it is for

Oncological and musculoskeletal radiologists who report WB-MRI, haematologists managing myeloma and smouldering myeloma, and uro-oncologists following metastatic prostate cancer. Researchers use the structured burden and response data in clinical trials.

Accepted input

• DICOM whole-body MR study (MR Image, Enhanced MR or Legacy Converted Enhanced MR), with its multiple stations, as a zip or by DICOMweb STOW-RS. NIfTI with a BIDS-style sidecar on the API.
• Prior whole-body MRI in prior_files for response assessment.
• Each station and sequence is recognised from acquisition tags, including b-values and Dixon water, fat, in-phase and opposed-phase images.

Requirements

Requirement	Why
T1 Dixon (fat and water images)	Marrow fat replacement and fat fraction
DWI with ADC	Cellular marrow lesions and diffuse infiltration
STIR or T2	Marrow oedema and lesion conspicuity
Prior study of the same protocol	Response categories in both sections

A study missing DWI or Dixon is reported with the missing sequence named rather than read on partial information.

Optional context

The diagnosis (myeloma, smouldering myeloma, prostate cancer), treatment dates and the date of the previous study go in clinical_context; they decide which reporting frame the result emphasises.

The result

Section	Content
Myeloma	Focal and diffuse marrow infiltration, focal lesion count, response category against the prior
Bone metastases	Bone metastasis burden by region, response against the prior
Draft report	Opt-in (options.report): an English narrative that interprets the result for the reader (findings, impression, limitations); every number is checked against the findings

Standards

• DICOM: SEG for marrow lesions, SR TID 1500 for counts and measurements with tracking identifiers across visits, ADC and fat fraction as Parametric Maps, KOS key images and Encapsulated PDF.
• Myeloma: MY-RADS (2019) for acquisition, reporting and response assessment categories.
• Prostate cancer: MET-RADS-P for regional bone metastasis burden and response.
• Measurements: ADC in physical units, never intensity-normalised, so values can be followed between visits on the same protocol.

Reading the response

WB-MRI is often repeated to assess response. Both sections match lesions and regions to the prior and report change per region, which is where mixed response (some regions improving, others progressing) becomes visible.