Back to the list
Congress: ECR25
Poster Number: C-19056
Type: Poster: EPOS Radiologist (scientific)
Authorblock: R. Kapoor, V. Rangankar; Pune/IN
Disclosures:
Reetika Kapoor: Nothing to disclose
Varsha Rangankar: Nothing to disclose
Keywords: Musculoskeletal spine, MR, MR-Diffusion/Perfusion, Computer Applications-Detection, diagnosis, Imaging sequences, Tissue characterisation
Results

A total of 300 discs were evaluated in 100 adult subjects (mean age: 42.2±15.0 and female: male ratio of 1:1.3). Most of the patients were in overweight (47%) and normal (45%) BMI categories. Out of 300, 68 (22.7%) were normal (grade I) discs and 232 (77.4%) were DDs (grade II–VIII) with majority (263) in MPG I to V category.

The highest mean ADC and T2* values in normal discs were recorded at L3-L4 level and declined consistently from L3-L4 to L5-S1 (Fig. 4 A and B). ADC and T2* values in normal discs differed statistically significantly at corresponding ROIs at different lumbar disc levels and combined mean ADC and T2* values of NP were more than AF at all disc levels. Mean ADC and T2* values were highest at mid NP at each normal disc and declined to lowest at posterior NP and AF (Fig. 4 A and B). Mean ADC and T2* values in anterior AF and NP were higher than posterior AF and NP. No significant correlation between T2* and ADC values with age was noted for the normal disc.

Statistically significant negative correlation was noted between age and T2* and ADC values for the central region of DDs with respective Spearman correlation coefficient (r) of −0.62/−0.66 at L3-L4, −0.64/−0.7 at L4/L5 and −0.38/−0.34 at L5/S1 level.  ADC and T2* values in NP, AF and entire disc were significantly lower in DD from normal discs (P-value <0.001). From Grade I to Grade VIII, mean ADC value ranged from 2831.1±64.9 to 211.1±161.8 x 10-6 mm2/s and 2812.9±75.4 to 236.7±172.1 x 10-6 mm2/s, in NP and AF respectively. Similarly, from Grade I to Grade VIII, the mean T2* value ranged from 187.3±16.7 to 15.3±3.6 ms and 174.7±19.1 to 22.8±9.8 ms in NP and AF, respectively.  Mean ADC and T2* values of NP decrease significantly as compared to AF with increasing subsequent grades (Grade II to Grade VIII) with drastic reduction in values of advanced degeneration grades VI, VII, and VIII (Fig. 5 A and B).  Mean ADC (Fig. 6A) and T2* (Fig. 6B) values were inversely proportional to increasing grades with strong negative correlation (P-value <0.001) with MPG irrespective of disc levels.

The cut-off values of ADC (Table 2) and T2* (Table 3) in the central region for Grades I to V were significant (P-value of <0.001). Area under the curve (AUC) was within the moderate to high accuracy range (0.8 to >0.9) for ADC and high accuracy range (>0.9) for T2* values in MPG Grades I to V(Fig.7). The sensitivity of T2* value increased from Grade I to Grade V.  Statistically significant marginally stronger negative correlation of T2* values (r = 0.96 for central and peripheral) and strong negative correlation of ADC values (r = 0.95 for central and peripheral) with MPG was noted (Table 4).  Overall, AUC for both ADC and T2* values were in the high accuracy range (0.98), irrespective of different grades (Fig. 8).

The primary limitation of our study was the lack of inter-observer variability and repeatability as a single reader defined the ROIs and obtained ADC and T2* values. Manual demarcation of the ROI to cover the interior portion of IVD might have introduced subjectivity and bias. No histological correlation of ADC and T2* values was obtained with various disc degenerative grades. The study did not consider disc loading conditions, potential diurnal variations, and other influencing elements, including exercise, mechanical stress, obesity, smoking, and hereditary factors for LDDD.
GALLERY