Detection of Leukocortical Lesions in Multiple Sclerosis and Their Association with Physical and Cognitive Impairment: A Comparison of Conventional and Synthetic Phase-Sensitive Inversion Recovery MRI

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Fig 1.
Leukocortical lesion count and volume on conventional and synthetic PSIR.
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Fig 2.
Comparison between conventional and synthetic phase-sensitive inversion recovery. A comparison between conventional (B and D) and synthetic phase-sensitive inversion recovery (A and C) illustrates 2 leukocortical MS lesions in a 40-year-old female patient with MS. Lower row illustrates the manual segmentation of the lesions by a neuroradiologist.

Table 1:

Demography of the study population^c

	Patients with MS
Female/male	14:7
Age (yr)	44.5 ± 12
Disease duration (yr)	14.5 ± 9.7
MS subtype (RR/SP/PP) (No.)	13/7/1
Disease-modifying therapy (No.) (%)	14 (67%)
EDSS score (median) (interquartile range)	2.0 (2.0)
Symbol Digit Modalities Test, z scores (median) (interquartile range)	−0.48 (1.46)
Verbal Fluency Test z scores	−0.37 ± 1.37
Fatigue Severity Scale score	4.53 ± 1.79

Note:—RR indicates relapsing-remitting; SP, secondary-progressive; PP, primary-progressive.
a Values reported as mean ± SD unless otherwise specified.

Table 2:

Image-acquisition parameters

Sequence Type	Synthetic PSIR	Conventional PSIR	MPRAGE	FLAIR
Acquisition plane	2D axial	2D axial	3D sagittal	3D sagittal
Matrix	256 × 204	256 × 204	256 × 256	256 × 256
In-plane resolution (mm)	0.9 × 0.9	0.9 × 0.9	1.0 × 1.0	1.0 × 1.0
Slices (No.)	34	34	176	160
Slice thickness (mm)	3.0	3.0	1.0	1.0
Distance factor	0.5	0.5	–	–
Flip angle	120°	120°	9°	120°, T2 variable
TR (ms)	4820^{^a} (6000^{^b})	6000	2300	6000
TE (ms)	22/100^{^a} (10^{^b})	10	2.98	388
TI (ms)	150/580/2000/4130^{^a} (500^{^b})	500	900	2100
Acquisition time (min:sec)	7:47	3:32	5:15	7:02

Note:—TR indicates repetition time; TE, echo time; TI, inversion time.
↵a Synthetic MRI is based on a single quantitative acquisition that is then used to generate synthetic images post hoc.
↵b Settings for the generation of synthetic PSIR are in parentheses.

Table 3:

Comparison of leukocortical lesion counts and volumes on conventional and synthetic PSIR^{^a}

	Conventional PSIR	Synthetic PSIR	P Value Conventional vs Synthetic PSIR^{^b}	Consensus Rating	P Value Conventional/Synthetic PSIR vs Consensus Rating^{^b}
Leukocortical lesion count, Rater 1 (No.)	7 ± 17	5 ± 26	.47	5 ± 30	.14/.06
Leukocortical lesion count, Rater 2 (No.)	7 ± 34	7 ± 29	.08	5 ± 30	.008/.96
Leukocortical lesion volume (mL)	0.53 ± 2.46	0.32 ± 2.89	.17