Brain MRI

What it does

Brain MRI reads the most frequently ordered MRI exam, from the overnight stroke scan to the anti-amyloid safety follow-up. The run first identifies every sequence from its acquisition parameters and image content, since series descriptions are free text, and then infers the indication from the order text or from the sequences present (contrast-enhanced T1 with FLAIR suggests tumour or MS, a TOF-MRA suggests an aneurysm question).

Every section the sequences support is computed in the same run: a critical-finding screen, acute infarct with DWI-ASPECTS, glioma and metastasis segmentation with RANO measurements, MS lesions by McDonald location, white matter disease, microbleeds and ARIA, volumetry with normative percentiles, focal cortical dysplasia and hippocampal sclerosis signs for epilepsy, and aneurysms on MRA. With a prior study, lesions are matched and change is reported per lesion.

Intended use

Decision support for physicians reading brain MRI: a structured second read for the resident on call who must not miss a 3 mm metastasis or a new MS lesion, and quantification that is slow by hand (lesion volumes, hippocampal percentiles, RANO products). Every detection comes with its mask and measurements.

Who it is for

Neuroradiologists, general radiologists and teleradiologists, with results going to neurologists, neuro-oncologists, neurosurgeons, stroke teams and memory clinics. Through the API, the same run feeds PACS worklists, radiosurgery planning and trial read workflows.

Accepted input

• DICOM: MR Image, Enhanced MR and Legacy Converted Enhanced MR objects, uploaded as a whole study (zip or DICOMweb STOW-RS). Secondary captures and screenshots are ignored.
• NIfTI on the API, with a BIDS-style JSON sidecar giving the sequence label, TR/TE/TI and b-values.
• One prior study in prior_files for RANO response, new MS lesions, ARIA, aneurysm growth and annualised atrophy.

Sequences per section

Section	Required	Optional
Acute stroke	DWI (b1000) and ADC	FLAIR, SWI
Brain tumour	T1, contrast-enhanced T1, T2, FLAIR	—
Brain metastases	Contrast-enhanced T1	T1, T2, FLAIR
MS lesions	3D FLAIR and 3D T1	Contrast-enhanced T1, prior
White matter hyperintensities	FLAIR (any resolution)	T1
Microbleeds	SWI or T2*-GRE	T1
ARIA monitoring	FLAIR and SWI or T2*-GRE, plus a baseline study	—
Epilepsy	3D T1 and FLAIR	—
Volumetry and brain age	3D T1	Other contrasts accepted
Aneurysms	3D TOF-MRA	Prior MRA

When a section's required sequence is missing, the result names it instead of guessing. Vendor, field strength and contrast status are recorded with every result, because microbleed counts depend on SWI versus T2*-GRE and on field strength.

Optional context

The order text or clinical question, age and sex (normative percentiles, brain-age gap) and treatment history (radiotherapy date, anti-amyloid therapy) go in clinical_context.

The result

Section	Content
Critical-finding triage	Flags for acute infarct, mass with mass effect, hydrocephalus or midline shift and blood on SWI
Acute stroke	Infarct mask and volume, vascular territory, DWI-ASPECTS, DWI–FLAIR mismatch, haemorrhagic transformation flag
Brain tumour	Glioma, meningioma or paediatric tumour: enhancing tumour, non-enhancing core, oedema and resection cavity masks, volumes, RANO 2.0 bidimensional measurements
Brain metastases	Each lesion segmented (enhancing, necrosis, oedema) with count, volume, longest diameter and location; RTSTRUCT for radiosurgery on request
Treatment response (RANO)	Lesion matching against baseline or nadir, volume and product change, RANO 2.0 or RANO-BM category
MS lesions	Lesion count and volume, periventricular, juxtacortical/cortical and infratentorial location, enhancing and new or enlarging lesions
White matter hyperintensities	Periventricular and deep volumes, Fazekas grade
Small vessel disease	Lacunes, enlarged perivascular spaces, microbleeds, WMH and total SVD score
Microbleeds	Count, lobar versus deep distribution, cortical superficial siderosis flag
ARIA monitoring	New ARIA-E and ARIA-H against baseline with radiographic severity
Brain volumetry	Structure volumes, hippocampal volume and asymmetry with age and sex percentiles, atrophy pattern, MTA/GCA equivalents; annualised atrophy with a prior
Epilepsy	Focal cortical dysplasia clusters with a confidence; hippocampal volume, asymmetry and FLAIR signal
Intracranial aneurysms	Location, size and volume, growth against prior, circle of Willis variants
Brain age	Predicted brain age and brain-age gap with uncertainty
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 every mask, SR TID 1500 with TID 1411 volumetric measurements and tracking identifiers so a lesion keeps its identity across visits, RTSTRUCT for radiosurgery targets, KOS key images and Encapsulated PDF.
• Oncology: RANO 2.0 (2023), RANO-BM (2015) and BT-RADS (2018).
• MS and vascular: McDonald 2017 with MAGNIMS-CMSC-NAIMS 2021, Fazekas, STRIVE-2 (2023), Boston criteria v2.0.
• Anti-amyloid therapy: ARIA-E/ARIA-H severity per the AJNR 2022 recommendations, with microbleed counts reported against the lecanemab (2023) and donanemab (2025) appropriate-use recommendations.
• Stroke, epilepsy and aneurysm: DWI-ASPECTS, DWI–FLAIR mismatch as in WAKE-UP, AHA/ASA 2019, ILAE 2022 FCD classification, PHASES inputs.

Volumetry percentiles sit in a normative block, and every tracked lesion keeps its tracking_uid across visits.