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Am J Nucl Med Mol Imaging 2013;3(3):261-271

Original Article
Re-evaluating the potentials and limitations of 99mTc-aprotinin scintigraphy for
amyloid imaging

Ryogo Minamimoto, Kazuo Kubota, Kenji Ishii, Miyako Morooka, Momoko Okasaki, Yoko Miyata, Kazuhiko Nakajima, Takashi Sato,
Toru Igari, Risen Hirai, Osamu Okazaki

Division of Nuclear Medicine, Department of Radiology, National Center for Global Health and Medicine, Tokyo, Japan; Positron
Medical Cen-ter, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan; Division of Pathology, Department of Central Laboratory,
National Center for Global Health and Medicine, Tokyo, Japan; Division of Hematology, Internal Medicine, National Center for Global
Health and Medicine, Tokyo, Japan; Department of Cardiology, National Center for Global Health and Medicine, Tokyo, Japan

Received February 20, 2013; Accepted March 15, 2013; Epub April 9, 2013; Published April 15, 2013

Abstract: The definitive diagnosis of amyloidosis is made histologically with Congo red stain. Noninvasive imaging techniques for
amyloidosis are beneficial for early and definite diagnosis of amyloid deposition in the body. 99mTc-aprotinin has the benefit of
detecting amyloid deposits mainly in the heart, but it can also detect a wide range of lesions in other locations. The usefulness and
limitations of 99mTc-Aprotinin scintigraphy for amyloid imaging were re-evaluated based on results from 25 patients (15 men and 10
women; median age, 62.9 y; range, 34-83 y). In addition, other nuclear tracers for imaging amyloidosis are discussed. Of the 25
patients with suspected amyloidosis, 19 patients were proven to have amyloid deposits by histopathological diagnosis. Major
99mTc-aprotinin positive sites were confirmed in the myocardium, thyroid, large joints, vertebrae, colon, and lungs. If
99mTc-Aprotinin images showed positive findings, the sensitivity, specificity, positive predictive value (PPV), and negative predictive
value (NPV) of existing amyloid deposits were 94.7, 33.3, 81.8, and 66.7%, respectively. For analysis based on biopsy region, the
sensitivity, specificity, PPV, and NPV of existing amyloid deposition were 30.6, 82.6, 73.3, and 43.2%, respectively. 99mTc-Aprotinin
has a high potential for diagnosis of amyloid deposition in body; however, due to its physiological uptake, its potential is limited for
detection of amyloid deposits in the liver, kidney, and spleen.

Keywords: 99mTc-aprotinin, amyloidosis, SPECT/CT, SPECT, scintigraphy

Address correspondence to: Ryogo Minamimoto, Division of Nuclear Medicine, Department of Radiology, National Center for Global
Health and Medicine, 1-21-1, Toyama, Shinjyuku-ku, Tokyo, 162-8655, Japan. Phone: +81-3-3202-7181; Fax: +81-3-3207-1038;
E-mail: ryogominamimoto@yahoo.co.jp