Susceptibility-Weighted Imaging Improves the Diagnostic Accuracy of 3T Brain MRI in the Work-Up of Parkinsonism

Article Figures & Data

Download figure
Open in new tab
Download powerpoint
Fig 1.
A–D, SWI with a circular region of interest in the left dorsal putamen. A, Grade 0 hypointensity (SI > 200) in a patient diagnosed with PD. B, Grade 1 hypointensity (SI > 150 but <200) in a patient diagnosed with PD. C, Grade 2 hypointensity (SI > 75 but <150) in a patient diagnosed with DLB. D, Grade 3 hypointensity (SI < 75) in a patient diagnosed with MSA-P. E, T2 TSE image of the patient diagnosed with MSA-P shown in D. Hypointensity of the putamen is less pronounced, though atrophy of the putamen is seen.
Download figure
Open in new tab
Download powerpoint
Fig 2.
ROC curves to evaluate diagnostic accuracy. Point 1 indicates the brain MR imaging “MSA” score to identify MSA-P, threshold 2 abnormalities (left figure), and the MR imaging “Sum” score to identify AP as a group, threshold 4 abnormalities (right figure). Point 2 is the grade 3 SWI hypointensity of the dorsal putamen. Point 3 indicates points 1 and 2 combined. SWI increases sensitivity with preservation of high specificity.

Table 1:

MRI scanning protocol

Sequence	TR (ms)	TE (ms)	Flip Angle	Voxel Size (mm)	No. and Direction of Sections	iPAT Factor	Acquisition Time (min:sec)
T2 TSE	5830	120	120°	0.6 × 0.6 × 3	48 Axial	–	3:43
T1 MPRAGE	2300	4.71	12°	1 × 1 × 1	192 Sagittal	2	5:47
T2 FLAIR	9000	86	150°	0.7 × 0.6 × 5	28 Axial	2	2:44
Proton-attenuation	2000	20	90°	0.9 × 0.9 × 3	48 Axial	–	7:16
DWI-EPI (b=0 and b=1000)	3900	89	90°	1.3 × 1.3 × 5	48 Axial	2	2:10
SWI gradient-echo	29	20	15°	0.6 × 0.6 × 3	48 Axial	2	4:42

Table 2:

Patient characteristics^{^a}

	PD (n = 38)	AP (n = 18)	MSA-P (n = 12)	PSP (n = 3)	DLB (n = 3)	HC (n = 13)
Age (yr)	61 (9)	65 (8)	63 (9)	67 (5)	69 (3)	67 (7)
Sex (M/F)	23:15	9:9	6:6	1:2	2:1	9:4
Disease duration (mo)	19.1 (14)	15.2 (12)	15.5 (11)	23.0 (20)	6.7 (7)	–
UPDRS-III	32.1 (12)	45.2 (11)	45.5 (12)	47.5 (13)	42.7 (11)	–
H&Y	1.7 (0.7)	2.6 (0.9)	2.6 (1.0)	3.0 (0)	2.3 (0.6)	–
MMSE	28.5 (1.6)	28.1 (1.6)	28.4 (1.4)	28.7 (0.6)	26.0 (1.0)	–

Note:—UPDRS-III indicates Unified Parkinson's Disease Rating Scale–III; H&Y, Hoehn and Yahr Staging Scale; MMSE, Mini-Mental State Examination.
↵a Data are mean or number (SD).

Table 3:

Frequency (%) of positive results^{^a}

	PD (n = 38)	MSA-P (n = 12)	PSP (n = 3)	DLB (n = 3)	Sensitivity/Specificity	κ (Interrater)
“MSA” score, threshold 1	11 (29)	10 (83)	1 (33)	3 (100)	83%/66% for MSA	0.64
“MSA” score, threshold 2	2 (5)	3 (25)	0 (0)	1 (33)	25%/93% for MSA	0.59
“PSP” score, threshold 1	0 (0)	1 (8)	3 (100)	0 (0)	100%/98% for PSP	0.88
“Atrophy” score, threshold 2	7 (18)	4 (33)	3 (100)	2 (67)	67%/74% for DLB	0.86
“Sum” score, threshold 2	9 (24)	8 (67)	3 (100)	3 (100)	78%/76% for AP	0.75
“Sum” score, threshold 3	8 (21)	5 (42)	3 (100)	2 (67)	56%/79% for AP	0.80
“Sum” score, threshold 4	4 (11)	4 (33)	3 (100)	2 (67)	50%/89% for AP	0.64