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MPR and 3D

MPR and 3D volume rendering on iPhone and iPad

Ossidex rebuilds a CT, CBCT or MRI series into a volume and shows it as axial, sagittal and coronal planes with linked crosshairs, oblique planes and adjustable slab thickness (MIP), plus a 3D volume rendering you can rotate and clip — on iPhone and iPad, without a workstation.

By the Ossidex team · How we write and check these pages · Updated

Download on the App StoreFree to download · iPhone & iPad · iOS 17+
Axial, sagittal and coronal MPR of a head CT with linked reference lines in Ossidex on iPad

Multi-planar reconstruction

  • Three orthogonal planes with colour-coded reference lines; drag a line to move the other planes.
  • Tilt planes for oblique views, and set slab thickness for maximum-intensity projection in the same gesture.
  • Window/level presets for bone, soft tissue and sinuses, synced across planes.
  • Drag a view to any panel to build the layout you want.

3D volume rendering

The 3D view renders the whole volume on the GPU. Rotate and zoom with your fingers, switch presets (bones is the default; teeth and airway are available) and move a clipping plane to look inside. It is useful for orientation, patient explanation and seeing the overall anatomy of a fracture, an impacted tooth or the airway.

3D rendering of a skull from CBCT with a clipping plane in Ossidex on iPhone

Linked series for MRI

Open several MRI series side by side; scrolling one moves the reference lines in the others, so you can follow a structure across sequences.

Requirements

MPR and 3D need a volumetric series — CT, CBCT or 3D MRI with enough slices. Single X-ray images and 2D MRI series with large gaps open in the 2D viewer. MPR and 3D are Pro features on your own studies and free to try on the sample CBCT.

Tips for better reformats

  • Thin slices give better MPR. A 0.2–0.4 mm CBCT reformats cleanly in every plane; a CT reconstructed at 5 mm looks blocky in sagittal and coronal views.
  • Pick the right series. Many CT studies include both a thick “review” series and a thin reconstruction — open the thin one for MPR and 3D.
  • Window before you judge. Bone, soft tissue and sinus presets change what is visible far more than zoom does.
  • Use slab sparingly. A thin slab follows a curved root; a thick slab hides small details behind brighter structures.

Using MPR on an iPad

  1. Open a volumetric series. CT, CBCT or 3D MRI with thin, contiguous slices.
  2. Switch to MPR. The screen splits into axial, sagittal and coronal views with colour-coded lines.
  3. Navigate. Drag a reference line to move the other planes, or scroll inside a view to step through slices.
  4. Tilt and thicken. Rotate a line for an oblique plane; increase slab thickness for a maximum-intensity projection that shows vessels or a curved root in one image.
  5. Arrange. Drag views into the panels you prefer and adjust window/level once for all planes.

Which mode for which question

QuestionBest view
Where exactly is a structure in 3D space?MPR with linked crosshairs
Follow a curved root or canalOblique MPR with a thin slab
See vessels or dense structures in one imageThick slab MIP
Overall shape of a fracture, impacted tooth or airway3D volume with clipping
Dental arch overviewPanoramic arch

Performance

Volumes are built once and cached on the device, so reopening a large CBCT is quick. Rendering runs on the GPU with Apple’s Metal; on recent iPhones and iPads MPR and 3D stay interactive while you drag. Very large multi-series studies are most comfortable on iPads with more memory.

Frequently asked questions

Can I do MPR on an MRI?

Yes, when the series is volumetric (thin, contiguous slices). For typical 2D MRI sequences with thick slices, reformatting is limited by the data itself.

Is 3D rendering slow on an iPhone?

Rendering runs on the GPU and is interactive on recent iPhones and iPads. Very large studies are smoother on iPads with more memory.

Can I export the 3D view?

Yes, as an image. Pro removes the export limit.

Can I try MPR and 3D for free?

Yes, on the built-in sample CBCT, which has every tool unlocked. On your own studies MPR and 3D are part of Pro.

Does 3D work for MRI?

For volumetric MRI series, yes; presets are tuned for CT and CBCT, so adjust window/level for MRI.

Related pages

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