Comparison of 3T and 7T susceptibility-weighted angiography of the substantia nigra in diagnosing Parkinson disease.
OBJECTIVE
Standard neuroimaging fails in defining the anatomy of the substantia nigra and has a marginal role in the diagnosis of Parkinson disease. Recently 7T MR target imaging of the substantia nigra has been useful in diagnosing Parkinson disease. We performed a comparative study to evaluate whether susceptibility-weighted angiography can diagnose Parkinson disease with a 3T scanner.


METHODS
Fourteen patients with Parkinson disease and 13 healthy subjects underwent MR imaging examination at 3T and 7T by using susceptibility-weighted angiography. Two expert blinded observers and 1 neuroradiology fellow evaluated the 3T and 7T images of the sample to identify substantia nigra abnormalities indicative of Parkinson disease. Diagnostic accuracy and intra- and interobserver agreement were calculated separately for 3T and 7T acquisitions.


RESULTS
Susceptibility-weighted angiography 7T MR imaging can diagnose Parkinson disease with a mean sensitivity of 93%, specificity of 100%, and diagnostic accuracy of 96%. 3T MR imaging diagnosed Parkinson disease with a mean sensitivity of 79%, specificity of 94%, and diagnostic accuracy of 86%. Intraobserver and interobserver agreement was excellent at 7T. At 3T, intraobserver agreement was excellent for experts, and interobserver agreement ranged between good and excellent. The less expert reader obtained a diagnostic accuracy of 89% at 3T.


CONCLUSIONS
Susceptibility-weighted angiography images obtained at 3T and 7T differentiate controls from patients with Parkinson disease with a higher diagnostic accuracy at 7T. The capability of 3T in diagnosing Parkinson disease might encourage its use in clinical practice. The use of the more accurate 7T should be supported by a dedicated cost-effectiveness study.
From the IMAGO7 Foundation (M. Cosottini, M. Costagli), Pisa, Italy Department of Translational Research and New Technologies in Medicine and Surgery (M. Cosottini, G.D.) mircocosottini@libero.it.
M
M
Cosottini
Neurology Unit (D.F., R.C., U.B.), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
D
D
Frosini
Neuroradiology Unit (I.P., P.C.), Department of Diagnostic and Interventional Radiology, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy.
I
I
Pesaresi
Department of Translational Research and New Technologies in Medicine and Surgery (M. Cosottini, G.D.).
G
G
Donatelli
Neuroradiology Unit (I.P., P.C.), Department of Diagnostic and Interventional Radiology, Azienda Ospedaliero Universitaria Pisana, Pisa, Italy.
P
P
Cecchi
From the IMAGO7 Foundation (M. Cosottini, M. Costagli), Pisa, Italy.
M
M
Costagli
Stella Maris Scientific Institute (L.B., M.T.), Pisa, Italy.
L
L
Biagi
Neurology Unit (D.F., R.C., U.B.), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
R
R
Ceravolo
Neurology Unit (D.F., R.C., U.B.), Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
U
U
Bonuccelli
Stella Maris Scientific Institute (L.B., M.T.), Pisa, Italy.
M
M
Tosetti
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010300:Parkinson Disease / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013378:Substantia Nigra / Q000000981:diagnostic imaging*