[Utility of the Method for Calculating the Heart to Contralateral Ratio for Cardiac Amyloidosis by Using Ray-summation Images in 99mTc-pyrophosphate Scintigraphy].

Abstract

PURPOSE:

The purpose of this study was to avoid the influence of background activity in the calculation of heart to contralateral ratio (H/CL) in 99mTc-pyrophosphate (PYP) scintigraphy for diagnosis of cardiac amyloidosis. Therefore, we investigated the utility of the H/CL calculation method using ray-summation (ray-sum) images created by multi-planar reconstruction and summing slices of the heart range from single-photon emission computed tomography (SPECT) images.

METHODS:

The subjects were 33 patients who underwent 99mTc-PYP planar and SPECT/CT at 3 hours after injection. Ray-summation axial (ray-sum axial) and ray-summation coronal (ray-sum coronal) images were created and H/CL was calculated. We compared the differences in sensitivity, specificity, accuracy, and area under the curve (AUC) between the conventional method and our method, and calculated the cutoff values.

RESULTS:

Comparison of the conventional method and our method showed no significant difference in sensitivity and AUC, while specificity was significantly improved to 97% (p=0.003) of ray-sum axial image and 90% (p=0.01) of ray-sum coronal image, and accuracy was significantly improved to 94% (p=0.02) of ray-sum axial image.

CONCLUSION:

The H/CL calculation method using ray-sum images had higher diagnostic performance than the conventional method, with optimal cutoff of ray-sum axial images 3.07 and ray-sum coronal images 2.77.

• Authors: Kei Takata, Naoki Shibutani, Hirokazu Horita
• Journal: Nihon Hoshasen Gijutsu Gakkai zasshi (Nihon Hoshasen Gijutsu Gakkai Zasshi) Vol. 78 Issue 12 Pg. 1399-1405 (Dec 20 2022) ISSN: 1881-4883 [Electronic] Japan
• PMID: 36288937 (Publication Type: English Abstract, Journal Article)

Chemical References

• diphosphoric acid
• Diphosphates
• Radiopharmaceuticals

Topics

• Humans
• Diphosphates
• Heart (diagnostic imaging)
• Radionuclide Imaging
• Amyloidosis (diagnostic imaging)
• Tomography, Emission-Computed, Single-Photon (methods)
• Radiopharmaceuticals