Quantitative DT-MRI analysis was performed in 22 patients aged 9–54 years (average 25 years, 13 males, 11 females) and in 8 healthy volunteers (control group) aged 22–57 years (average 33 years, 5 males, 3 females). All 22 patients were in coma (GCS of 4–8, average 6) on admission to the Burdenko Neurosurgery Institute, which lasted 3–20 days (average 12 days). CT revealed signs of DAI in all patients (categories I–IV according to Marshall et al. 1991). The outcomes in 3 months after injury in the analyzed group were as follows: good recovery in 3 patients, moderate disability in 7, severe disability in 9, and vegetative state in 3. MRI studies for these 22 patients were performed within 2–17 days of TBI, average of 10 days. The selection criteria for MRI studies were as follows: stabilization of patient’s condition, normalization of intracranial pressure and hemodynamics, adequate ventilation, and absence of metallic implants.

No statistically significant differences were found in ADC and FA between the right and left sides in the control group (Table 4.1). For this reason, all bilateral measurements in the control subjects were averaged.

At the same time, average FA values in the control group along the corticospinal tracts at the level of pons were significantly lower compared to cerebral peduncles and internal capsule (Fig. 4.1).

The results of comparisons of bilateral ADC and FA values in seven patients without paresis are presented in Table 4.2.

Table 4.2 shows that no statistically significant differences were noted for ADC and FA between the right and left sides along corticospinal tracts in patients without motor disturbances. Thus, they were also averaged. The average ADC and average FA values in this group were compared with those in the control group (Table 4.3).

There was a statistically significant FA value reduction along the corticospinal tracts in patients without hemiparesis compared with the control group, but no differences were observed for ADC values in any region (Table 4.3).

A statistically significant FA reduction was found at the cerebral peduncle level (p < 0.05) in the homolateral to hemiparesis CST in patients with hemiparesis (n = 11) compared to the control group (Table 4.4).

Statistically significant differences were observed for FA in the posterior limb of the internal capsule (PLIC) and peduncles and for ADC in PLIC on the contralateral to hemiparesis side of CST in patients with hemiparesis compared to the control group (Table 4.5).

A statistically significant difference in FA values was found in the cerebral peduncles and PLIC between homolateral and contralateral sides in patients with hemiparesis (Table 4.6, Fig. 4.2).

A statistically significant FA reduction was noted in all regions of interest along the CSTs when comparing 4 patients with tetraparesis to the control group (Table 4.7).

The study showed that FA values in the corpus callosum and along the corticospinal tracts as well as ADC values in the splenium of the corpus callosum significantly correlated (p < 0.01) with outcome in patients examined within 10–17 days after TBI (Table 4.8). However, there was no significant correlation between clinical outcome and diffusion parameters when patients were scanned 2–9 days following trauma.

Comparisons of average ADC and FA values for the genu and splenium of the corpus callosum were performed in all groups of patients with DAI: with no paresis (7), with unilateral paresis (11), with tetraparesis (4), and in control group (8) (Table 4.9).