Keywords:
Neuroradiology brain, CNS, MR, MR-Diffusion/Perfusion, Diagnostic procedure, Comparative studies, Inflammation
Authors:
M. Kumar1, R. JAMWAL2, V. Krishnan3; 1New Delhi/IN, 2NEW DELHI, DELHI/IN, 3New Delhi, Tamil Nadu/IN
DOI:
10.26044/ecr2019/C-0888
Results
A total of 40 subjects were analyzed with a total of 241 lesions on imaging being analyzed overall.
The age and sex distribution of the subjects were analyzed.
Majority of the patients in our study were in the age group of 21 to 40 years (45%).
Majority of the patients were female (23),
accounting for 57.5% of the subjects (Figure 9).
Among the total 40 subjects involved in the study,
24 were cases of MS,
14 were cases of ADEM,
and 2 were cases of NMO.
The age distribution of the individual conditions were also analyzed and tabulated (Table 1).
The distribution of the lesions were also analyzed and tabulated.
Of the 241 FLAIR hyperintense lesions in inflammatory demyelinating diseases,
majority of lesions were documented in the periventicular white matter accounting for 39.74% of the lesions,
whereas least number of lesions were documented in the cortical gray matter of occipital lobe accounting for 0.18% of the lesions (Table 2).
Lesions were predominantly located in the periventricular regions in MS (Figure 10) and subcortical regions in ADEM (Figure 11).
The acquired sample size of NMO was inadequate for further assessment.
Among the 241 FLAIR hyperintense lesions,
73 were observed to fit the size criterion of >8 mm and were selected for the study.
Out of the 73 lesions,
50 (68.48%) were found to show enhancement on CE T1WI.
51 of the selected lesions were observed in patients of MS,
out of which 38 showed contrast enhancement.
The remaining 22 lesions were observed in ADEM,
out of which 12 showed contrast enhancement (Table 3).
A total of 65 (89.04%) out of the 73 selected lesions showed hyperintense signal on DWI.
Out of these,
hypointense signal on ADC (true diffusion restriction) was shown by 7 (9.59%) lesions.
All of the 50 enhancing lesions were hyperintense on DWI.
Among the 23 non-enhancing lesions,
15 were hyperintense on DWI and 8 were non-hyperintense on DWI (Table 4).
However,
none of the non-enhancing lesions showed true diffusion restriction (Table 5).
20.55% of the non-enhancing lesions showed hyperintense signal on DWI but all were non-hypointense on ADC (T2 shine through).
Contrast enhancement as well as hyperintense signal on DWI were absent in 10.96% of the selected lesions.
In ADEM only 2.74 % of the lesions showed true diffusion restriction whereas in MS 6.85% of the lesions showed true diffusion restriction.
Interrater agreement between DWI hyperintensity and contrast enhancement was 0.422 (moderate) while interrater agreement between true diffusion restriction and contrast enhancement was 0.090 (poor) (Table 6).
The p value in all cases was <0.05.
Limitations:
- The spatial resolution and signal-to-noise ratio of DWI were relatively suboptimal compared to SE/FSE imaging
- Spinal cord lesions were not included in the study because DWI is not routinely used to evaluate the spinal cord due to its limitations like magnetic field inhomogeneity around the spine,
the small cross-sectional size of the spinal cord,
and the increased motion in that area due to breathing,
swallowing,
and cerebrospinal fluid pulsation
- The interval between symptom onset and MRI studies varied among subjects and this may have influenced the results