Patent-PendingVendor-NeutralPhysicist-ValidatedSub-mm Accuracy
Sub-Millimeter Geometric Truth for Stereotactic MRI

MR Geometricalâ„¢ maps, separates, and corrects MRI geometric distortion at the voxel level. Designed for stereotactic radiosurgery, MR-guided radiotherapy, surgical navigation, and MRI-only treatment planning.

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Built for TG-284 · TG-132 · DICOM-Native · Vendor-Neutral · Physicist-Reviewed

≤1 mm
SRS Targeting Margin

Gamma Knife and LINAC SRS require sub-millimeter geometric accuracy

1–2 mm
Peripheral Distortion

Typical uncorrected MRI distortion at imaging periphery

3
Distortion Components

Total · B₀-induced · Machine-specific — separated and quantified

The Problem
MRI Introduces Geometric Uncertainty

MRI geometric distortion has two independent, physically distinct sources. Vendor correction addresses only one.

Machine-Specific Distortion

Primarily driven by gradient nonlinearity and scanner-dependent field imperfections. Stable per scanner and sequence. Vendor correction partially addresses this component, but without independent quantitative verification.

Patient-Specific Distortion

Tissue susceptibility and chemical shift — varies per patient and sequence. Left uncorrected in every clinical scan.

Geometric Miss in SRS

SRS margins are often ≤1 mm. Peripheral MRI distortion routinely exceeds 1–2 mm.

Degraded MRgRT Adaptation

Uncorrected distortion propagates into daily dose accumulation and adaptive plan quality.

Unverified MRI-Only Planning

Without full distortion correction, synthetic CT generation and dose calculation are compromised.

How It Works
Three Steps from Phantom Scan to Corrected DICOM
Phantom Acquisition

The Gheadâ„¢ anthropomorphic 3D QA phantom is scanned on the clinical sequence. Its patient-realistic geometry and embedded marker lattice provide the ground-truth reference for full-volume distortion mapping.

Distortion Decomposition

A physics-grounded computational engine, augmented by AI-assisted modeling where appropriate, computes a voxel-level 3D displacement field across the full imaging volume. The engine separates machine-specific distortion (gradient nonlinearity, B₀ inhomogeneity) from patient-specific distortion (susceptibility, chemical shift) — independently, without relying solely on vendor-supplied correction models.

Corrected Output

Geometrically corrected DICOM is delivered at sub-millimeter accuracy, TPS-ready. A quantitative distortion report — signed by a board-certified medical physicist — documents all three distortion components for commissioning, QA, and regulatory records.

The Gheadâ„¢ anthropomorphic head phantom: a patient-realistic 3D reference geometry with an embedded marker lattice, scanned on your clinical sequences.

Validation
Built on a Rigorous Validation Framework

Every MR Geometrical™ output is grounded in a multi-layer validation methodology — from phantom-based ground truth to longitudinal scanner drift tracking.

Phantom-Based Geometric Ground Truth

The Gheadâ„¢ anthropomorphic phantom provides a patient-realistic 3D reference geometry. CT-to-MRI landmark registration establishes the ground-truth displacement field across the full imaging volume.

CT-to-MRI Landmark Verification

Independent CT scan of the phantom serves as the geometric reference standard. Landmark-based registration quantifies total distortion without relying on vendor-supplied correction data.

Longitudinal Scanner Drift Tracking

Repeated phantom acquisitions over time track machine-specific distortion drift. Automated trending against SRS/SBRT thresholds and TG-284 compliance benchmarks.

Physicist-Signed Commissioning Reports

Every commissioning and QA report is reviewed and signed by a board-certified medical physicist. Structured for regulatory documentation, accreditation, and institutional QA programs.

Multi-Site Validation Partnerships

Early-access centers contribute scanner data across GE, Siemens, and Philips platforms. Multi-site validation informs platform robustness and supports peer-reviewed publication.

Ghead™ — patient-realistic anthropomorphic head phantom with embedded 2 mm marker lattice.

Patent-Pending Platform & Hardware
Gheadâ„¢ Anthropomorphic Head Phantom

Purpose-built to replicate real human anatomy — including air cavities — and characterize both machine-specific and patient-specific MRI distortion.

Anthropomorphic Geometry

Scalp, cranial volume, and facial contour matched to real human head anatomy.

Realistic Air Cavities

Sinuses, nasal passages, and ear canals — the primary driver of patient-specific susceptibility distortion.

2 mm Marker Grid

Isotropic 3D lattice enabling sub-millimeter displacement detection across the full imaging volume.

Patent-Pending

Gheadâ„¢ and the MR Geometricalâ„¢ correction workflow are protected by filed U.S. patent applications.

MRI-Only PlanningPatent-Pending
Geometrically Accurate MRI-Only Radiotherapy Planning

MR Geometrical™ provides the geometric foundation for safe MRI-only simulation — enabling centers to generate geometrically corrected MRI and synthetic CT images, exported directly to your treatment planning system to support MRI-first workflows and synthetic CT generation where clinically appropriate.

Geometric Characterization

Ghead™ phantom scan on your clinical sequence. Full-volume 3D distortion map computed — machine-specific and patient-specific components separated.

Geometrically Corrected MRI

Patient MRI corrected to sub-millimeter geometric accuracy. Voxel-level displacement field applied. DICOM output verified by a board-certified physicist.

Synthetic CT Generation

AI-generated synthetic CT from the geometrically corrected MRI. Electron density maps for accurate dose calculation — no CT scanner required.

Direct TPS Export

Designed for DICOM export/import into commercial treatment planning systems including Eclipse, RayStation, Monaco, and Pinnacle.

Eliminate CT Simulation

Reduce dependence on CT simulation and support MRI-first planning workflows where clinically appropriate.

Sub-mm Geometric Accuracy

Geometric accuracy verified at the voxel level — not assumed. Every output includes a quantitative accuracy report.

Physicist-Signed at Every Step

A board-certified medical physicist reviews and signs every correction, synthetic CT, and accuracy report.

Deliverables
What You Get

Every MR Geometrical™ analysis delivers a complete, physicist-signed geometric accuracy package — from raw distortion maps to TPS-ready corrected DICOM.

Full-Volume 3D Distortion Maps

Per scanner, per sequence — with machine-specific and B₀-induced components separated. Exportable for independent review.

Geometrically Corrected MRI

DICOM output at sub-millimeter accuracy, compatible with Gamma Knife, LINAC, and MR-LINAC treatment planning systems.

Sub-mm Accuracy Verification Report

Quantitative distortion report signed by a board-certified medical physicist. Supports TG-284 compliance documentation.

MRSim Clinicalâ„¢ Pathway

Corrected MRI and field maps serve as the foundation for synthetic CT generation and MRI-only planning via MRSim Clinicalâ„¢.

Product Tour
Inside the Platform

A physics-grounded web application designed for secure clinical deployment — structured inputs, explainable outputs, physicist-signed reports.

One platform, three distortion components: total (CT vs MRI ground truth), B₀-induced, and machine-specific — separated, quantified, exportable.

Guided phantom workflow: load phantom MRI + CT + Bâ‚€ field map, set acquisition parameters, run three-component analysis, export machine-specific field.

Three correction modes — total phantom field, patient B₀ + machine field, or full CT-based — plus synthetic CT and anatomical CT↔MRI analysis. Export corrected DICOM to TPS.

Longitudinal geometric QA per scanner: machine-distortion and Bâ‚€-drift trending, isocenter vs peripheral tracking, SRS/SBRT thresholds, and TG-284 compliance history.

Per-session phantom QA log with machine-distortion metrics, B₀ drift values, and SRS threshold compliance — exportable to CSV.

Applications
Built for High-Stakes MRI Geometry

MR Geometrical™ is designed for clinical programs where geometric accuracy is not optional — where a millimeter matters.

Gamma Knife SRS

Stereotactic radiosurgery demands sub-millimeter isocenter accuracy. MR Geometricalâ„¢ provides independently verified geometric correction for Gamma Knife treatment planning MRI.

LINAC SRS / SBRT

Frame-based and frameless SRS on LINAC platforms. Full-volume distortion correction for single-fraction and hypofractionated stereotactic treatments.

MR-LINAC & Adaptive MRgRT

Daily adaptive MR-guided radiotherapy requires geometric fidelity on every fraction. MR Geometricalâ„¢ characterizes and corrects distortion for MR-LINAC platforms including Elekta Unity and ViewRay MRIdian.

Cranial Stereotactic & Functional Neurosurgery

Deep brain stimulation, focused ultrasound, and stereotactic biopsy planning require MRI geometry accurate to the sub-millimeter. MR Geometricalâ„¢ provides the verified geometric foundation.

MRI-Only Simulation

Eliminating CT from the radiotherapy simulation workflow requires MRI geometric accuracy equivalent to CT. MR Geometricalâ„¢ provides a foundational geometric QA layer for MRI-only planning and synthetic CT generation.

Deployment
Flexible Deployment for Clinical Programs

MR Geometrical™ is designed to integrate into existing clinical physics workflows — from initial site commissioning through ongoing longitudinal QA and patient-specific correction.

Site Commissioning

Full-volume phantom-based geometric characterization of your scanner(s). Physicist-signed commissioning report for institutional QA records and accreditation.

Longitudinal Scanner QA Subscription

Scheduled phantom re-acquisitions with automated drift trending. Continuous TG-284 compliance monitoring and threshold alerting per scanner.

Patient-Specific Correction Workflows

Per-patient Bâ‚€ field map integration for susceptibility-driven distortion correction. Applied at the sequence level for each clinical MRI acquisition.

MRI-Only Planning Integration

Geometrically corrected MRI and synthetic CT generation, exported to your TPS. Supports MRI-first simulation workflows where clinically appropriate.

Physicist Consulting via SpinTecx LLC

Direct access to board-certified medical physics expertise for commissioning support, QA program design, and clinical implementation guidance.

Early-Access Program
Partner With Us — Shape the Standard

MR Geometrical™ is in active development. We are opening early-access partnerships with Gamma Knife, SRS, and MRgRT centers who want to define the geometric accuracy standard — and have their clinical data inform the platform.

Priority Access

First access to the full platform — phantom workflow, patient correction, longitudinal QA, and physicist-signed reports — before general release.

Clinical Validation Partnership

Your scanner data and clinical sequences inform platform validation. Co-authorship opportunities on peer-reviewed publications.

Founding Partner Pricing

Early-access partners receive preferred pricing and direct input into the product roadmap.

MR Geometricalâ„¢ by PrecisionMRI.ai

Developed by SpinTecx LLC

precisionmri.ai
LinkedIn — Ali Fatemi

MR Geometrical™ is in development and not yet cleared for clinical use. Decision-support software for qualified medical physics professionals. MR Geometrical™ is a patent-pending software + hardware platform, including the Ghead™ phantom, distortion decomposition algorithms, and correction workflows. © 2026 PrecisionMRI.ai / SpinTecx LLC. All rights reserved.