Combined Diffusion Tensor Imaging and Apparent Transverse Relaxation Rate Differentiate Parkinson Disease and Atypical Parkinsonism

Article Figures & Data

Table 1:

Demographic and clinical data for control and patient groups^{^a}

	Control	PD	MSA-P	PSP	P Value
No. of subjects	36	35	16	19
Female/male	13:23	12:23	8:8	4:15	.356^{^b}
Age (yr)	70.0 ± 7.5	70.3 ± 7.9	68.0 ± 7.5	74.9 ± 8.7	.057^{^c}
Disease duration (yr)	–	3.4 ± 3.6	3.9 ± 3.3	3.2 ± 2.8	.812^{^c}
MoCA	25 ± 2.3	22.8 ± 4.5	23.9 ± 2.7	20.1 ± 4.9	.002,^{^d} .120^{^e}
UPDRS III	4.6 ± 3.6	36.6 ± 27.3	51.5 ± 20.0	46.6 ± 23.4	<.0001,^{^d} .145^{^e}

↵a Data are sums or mean ± SD.
↵b Group difference in sex was compared among all 4 groups using the χ² test.
↵c Group differences in age and disease duration were compared using 1-way ANOVA.
↵d Group differences in MoCA and UPDRS-III were compared among all 4 groups using ANCOVA with adjustments for age and sex.
↵e Group differences in MoCA and UPDRS-III were compared among the 3 patient groups, using ANCOVA with adjustments for age and sex.

Table 2:

Individual MRI measurements in PD, MSA-P, and PSP compared with controls in different structures

	PD			MSA-P			PSP
	FA	MD	R2*	FA	MD	R2*	FA	MD	R2*
Striatal and related structures
PUT					↑↑^{^a}			↑
CN
GP					↑↑↑^{^a}	↑	↑	↑
Midbrain structures
antSN				↓		↑		↑↑	↑
postSN	↓↓	↑	↑↑	↓		↑		↑↑↑↑^{^a}	↑↑
RN			↑↑^{^a}	↓	↑			↑	↑↑^{^a}
STN				↓↓^{^a}	↑	↑↑↑^{^a}			↑
Limbic structures
Hipp							↓	↑↑↑↑^{^a}	↓
AM				↓			↓	↑↑
Cerebellar structures
DN							↓	↑↑^{^a}
CB				↓↓	↑↑↑^{^a}		↓↓^{^a}	↑↑^{^a}
SCP							↓↓↓↓^{^a}	↑↑↑↑^{^a}
MCP				↓	↑↑↑^{^a}	↓↓↓^{^a}		↑↑^{^a}

Note:—antSN indicates anterior substantia nigra; postSN, posterior substantia nigra; Hipp, hippocampus; AM, amygdala; CB, cerebellum; DN, dentate nucleus; GP, globus pallidus; MCP, middle cerebellar peduncle; SCP, superior cerebellar peduncle.
↵a Statistical significance after Bonferroni correction (P < .0038, considering 13 independent tests). Upward arrows indicate increased MRI measures compared with controls, and downward arrows indicate decreased MRI measures compared with controls. ↑ represents P < .05, ↑↑ represents P < .01, ↑↑↑ represents P < .001, and ↑↑↑↑ represents P <0 .0001.

Table 3:

ROC analysis of individual and combined MRI modalities

	AUC	Sens	Spec	PPV	NPV	P Value^{^a}
C vs PD/MSA-P/PSP						.013
DTI+R2*	0.88	0.80	0.83	0.82	0.81
DTI^{^b}	0.80	0.81	0.71	0.60	0.87
R2*	0.75	0.69	0.69	0.55	0.81
C vs PD						.001
DTI+R2*	0.91	0.86	0.80	0.82	0.89
DTI	0.82	0.74	0.76	0.75	0.76
R2*	0.78	0.71	0.75	0.71	0.74
PD vs MSA-P/PSP						.038
DTI+R2*	0.94	0.86	0.87	0.88	0.84
DTI	0.89	0.83	0.80	0.82	0.81
R2*	0.87	0.87	0.77	0.87	0.77
PD vs MSA-P						.006
DTI+R2*	0.99	0.97	1.00	1.00	0.93
DTI	0.89	0.83	0.86	0.79	0.86
R2*	0.91	0.86	0.86	0.94	0.70
PD vs PSP						.156
DTI+R2*	0.99	0.97	1.00	1.00	0.94
DTI	0.97	0.94	0.94	0.97	0.89
R2*	0.87	0.80	0.83	0.82	0.81
MSA-P vs PSP						.435
DTI+R2*	0.98	0.94	1.00	1.00	0.93
DTI	0.96	0.94	0.92	0.94	0.92
R2*	0.89	0.86	0.80	0.82	0.81

Note:—Sens indicates sensitivity; Spec, specificity; PPV, positive predictive value; NPV, negative predictive value; AUC, area under the curve; C, controls.
↵a ROC curves were compared between the models, including all MRI measurements and that with DTI measurements only.
↵b Models for DTI measurements were generated by including both FA and MD features.