Usefulness of 67Ga SPECT and integrated low-dose CT scanning (SPECT/CT) in the diagnosis of cardiac sarcoidosis.
OBJECTIVE
We performed 67Gallium (Ga) single-photon emission computed tomography (SPECT) with integrated low-dose computed tomography (CT) for the interpretation of myocardial outline to investigate the value of co-registered fusion imaging using a hybrid system (SPECT/CT) in patients with cardiac sarcoidosis.


METHODS
SPECT/CT of the region in question was performed with VG Hawkeye. The subjects in this study were 37 patients [mean (+/-SD) age 61.0+/-13.0 years; 12 men and 25 women], 13 of whom had a clinical diagnosis of cardiac sarcoidosis and 24 a negative diagnosis. An intravenous injection of Ga (dosage 111 MBq) was performed on patients 48 h or 72 h before obtaining static planar images of the whole-body and the SPECT/CT scan.


RESULTS
Abnormal Ga uptake in the myocardium was observed in 10 of the 13 subjects with true sarcoidosis, and in 11 of 24 with negative sarcoidosis without CT fusion. The sensitivity without CT fusion was 77%, the specificity 54%, and the accuracy 62%. Use of SPECT/CT changed the diagnosis only in a patient with true sarcoidosis, and changed the diagnosis in eight patients with negative sarcoidosis. The sensitivity with CT fusion was 69%, the specificity 79%, and the accuracy 76%. The difference in diagnostic accuracy was statistically significant (McNemar's test, P=0.039).


CONCLUSIONS
SPECT scanning using Ga and integrated low-dose CT is a very useful diagnostic imaging technique because it improves the diagnostic specificity of Ga SPECT to allow the highly specific diagnosis of cardiac sarcoidosis.
Momose
Mitsuhiro
M
Department of Radiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan. m-momose@hsp.md.shinshu-u.ac.jp
Kadoya
Masumi
M
Koshikawa
Megumi
M
Matsushita
Tsuyoshi
T
Yamada
Akira
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D009202:Cardiomyopathies / Q000175:diagnosis*; D002951:Citrates; D005260:Female; D005708:Gallium; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012507:Sarcoidosis / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D018511:Systems Integration; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
D002951:Citrates; D019275:Radiopharmaceuticals; D005708:Gallium; C103850:gallium citrate