CARDIAC AMYLOIDOSIS'

Overview

AmyloidAnalyzer is a web-based tool for the quantitative analysis of bone scintigraphy images in the workup of cardiac ATTR amyloidosis. It calculates the Heart-to-Contralateral Lung (H/CL) ratio, the Retention Index (RI), and supports the Perugini Visual Score, following ASNC Practice Points 2021 and Bokhari et al. (Circ Cardiovasc Imaging 2013).

Step-by-Step Instructions

1. Load Images

Click 📁 Load file in each panel header.

1-hour panel (left): load the early post-injection chest image
3-hour panel (right): load the delayed chest image
Accepted formats: DICOM (.dcm) — required for quantitative analysis — or JPG/PNG (Perugini Score only)

⚠ DICOM must be uncompressed Explicit or Implicit Little Endian. If your PACS exports JPEG Lossless or JPEG 2000, re-export as uncompressed or save a screenshot as JPG.

2. Adjust Window Level (DICOM only)

Under each image, use the W/L and W/W sliders to optimise image contrast for ROI placement. Click ↺ to reset to the original values.

3. Draw the Heart ROI (1h panel)

Select ❤ Heart tool (red)
On the 1-hour image, click on the centre of the left ventricle and drag outward to set the radius
The circle should cover the entire myocardium without including lung or sternum
Release the mouse to confirm

All subsequent ROIs (CL Lung on 1h, and both ROIs on 3h) will automatically inherit this radius — this enforces the ASNC equal-sized ROI constraint.

4. Place the Contralateral Lung ROI (1h panel)

The tool switches automatically to 🫁 Contralateral Lung (blue) after the heart ROI is drawn
Single click on the centre of the right lung (mirror position of the heart)
The radius is locked to match the heart ROI

5. Copy ROIs to 3h Panel

Click ⇒ Copy ROI 1h → 3h to transfer both ROIs to the 3-hour image with identical size. Then reposition them if needed:

Hover over a ROI — the cursor changes to a ✋ hand
Click and drag to move it to the correct anatomical position

6. Place ROIs on 3h Panel (if not copied)

Use the same tools as above. Both ROIs on the 3h panel have their radius locked to the 1h ROIs — just click to position them.

7. Assign the Perugini Visual Score

In the 3-hour panel, select the score that best matches what you see on the image:

ScoreDescriptionInterpretation

0No cardiac uptakeNegative

1Heart uptake < rib uptakeEquivocal

2Heart uptake = rib uptakePositive

3Heart uptake > rib uptakeStrong Positive

Compare myocardial intensity to adjacent ribs and sternum on the 3-hour image.

8. Review Quantitative Results

Once both panels have ROIs drawn, the results panel shows:

H/CL 1h — early ratio (informational)
H/CL 3h — diagnostic ratio: ≥1.5 Positive | 1.3–1.49 Grey Zone | <1.3 Negative
Retention Index (RI = H/CL 3h − H/CL 1h): >0 = ATTR uptake | <0 = blood pool washout
Mean counts per ROI (cts/pixel) and total image counts

9. Generate the Report

Click 📄 Generate Report (top right). A pre-formatted report text is generated with:

Methodology, ROI parameters, quantitative indices
Perugini score and interpretation
Automatic conclusion based on combined H/CL + Perugini result

Click 📋 Copy all to copy to clipboard, then paste into your reporting system.

Diagnostic Rules (ASNC 2021)

Score ≥2 + H/CL 3h ≥1.5 + absence of monoclonal gammopathy → ATTR diagnosis confirmed without endomyocardial biopsy (sensitivity 97%, specificity 100%)
Grey zone or discordant results → correlate with serum/urine electrophoresis, immunofixation, and free light chain assay; consider late imaging (4–5h) or SPECT/CT

Technical Notes

FormatH/CL & RIPerugini ScoreWindow adjust

DICOM uncompressed✅✅✅

JPG / PNG❌✅❌

DICOM compressed❌ (re-export)✅ (as JPG)❌