Parathyroid subtraction

99mTc-MIBI − k · 99mTc-pertechnetate

1Images

99mTc-MIBI

Frame to use

99mTc-pertechnetate

Frame to use

You can drag the files straight onto the panels. DICOM files are read in the browser and are not sent anywhere.

2Thyroid ROI on the pertechnetate

Outline the thyroid freehand in the pertechnetate panel. The ROI stays attached to the pertechnetate during alignment and appears on MIBI, fusion and subtraction as an anatomical reference. You can draw several outlines, for example one per lobe.

3Pertechnetate alignment

MIBI is the reference image. Drag in the fusion or subtraction panel to move the pertechnetate; with Shift held down you rotate it.

Flip the pertechnetate horizontally

include rotation include size

Automatic alignment maximizes the correlation between the two images within the thyroid ROI (plus a margin) or, without a ROI, over the whole image.

Fusion

MIBI in magenta, pertechnetate in green: where they match the image looks gray.

Keyboard shortcuts

← → ↑ ↓: moves by 0.5 px (with Shift 2 px)
Q E: rotates by ∓0.5° (with Shift 2°)
+ −: size ±1%
M D V: move tool, draw ROI, move view
F: fit the view
Wheel: zoom all panels together
Right button: drags the view with any tool

4Equalization and display

Histogram equalization Color scale Apply the same settings to MIBI and pertechnetate

Filter and interpolation

Smoothing is applied to both images before subtraction and reduces Poisson noise.

Display with smooth interpolation

5Subtraction

Pertechnetate normalization

Set negative values to zero

Residual uptake

Highlight uptake above threshold

Search area

Anterior view: the left of the image is the patient's right

6Save the result

Include ROI and uptake in the PNG images

The DICOM is a Secondary Capture with the MIBI demographics and the processing parameters in the comments; it comes in a .zip archive together with a text file of the parameters.

ROI Uptake Crosshair

99mTc-MIBI

Drag the 99mTc‑MIBI DICOM file here

99mTc-pertechnetate

Drag the 99mTc‑pertechnetate DICOM file here

Fusion

The fusion appears when both images are loaded.

Subtraction

Load MIBI and pertechnetate to compute the subtraction.

Load the images to start. Processing support tool: it is not a certified medical device and does not replace the nuclear medicine physician's assessment.