Deep white matter ischemia (DWMI) is bilateral patchy or diffuse pattern of ischemia and demyelination in the deep white matter region of the brain. WM lesions (WMLs) increase in frequency with age and are associated with lower cognitive performance. Reported prevalence ranges from 5% to 90%, depending on study design, study population, and rating scales. Although the main pathophysiology is still under investigation, they are attributed to degenerative changes of long penetrating arteries and it has been postulated that chronic vascular diseases of the arteries and arterioles supplying these regions can play a role in the process. Deep white matter ischemia is imaged by using T2 weighted (T2W) sequences in addition to FLAIR sequences. Coronal section is used to enable precise sampling of WMLs
To assess 3T MRI vs. 1.5 MRI in evaluating the extent of DWMI.
PATIENTS AND METHODS:
A cross sectional study was conducted at the MRI unit of the Department of Radiology in Al-Imamain Al-Kadhimain Medical City in Baghdad. Data collection was obtained during the period starting on October 2015– June 2016. The study included 87 patients with the diagnosis of DWMI based on previous MRI data. Patients with initial MRI findings that show no evidence of DWMI as well as patients presented with trauma, migraine, epilepsy, tumor, TB and cerebral venous thrombosis were excluded. Each patient was examined by using 3T MRI, followed by a 1.5 T MRI two days later. The patient images were evaluated for 1.number of lesions, 2.size, 3.volume and 4.intensity of a selected prominent lesion.
Of the 87 patients, 51 were male and 36 female. Their mean age was 59.48 ± 10.83 years. In all lobes there is a statistical significance (P < 0.0001) between 3T and 1.5T i.e. 3T platform was able to show a greater number of lesions in comparison with the 1.5T platform. It was seen with high statistic significance (P <0.0001) that one the 3T images, mean intensities, sizes, and volumes were higher across the board. The average additional number of lesions shown by 3T over 1.5T was 9.52 lesions with a standard deviation of 6.50.
Three tesla MRI is significantly superior than1.5 tesla MRI in the number of detected lesions, determining size of a lesion, detecting lesion volume and intensity