X-ray and computed tomography scan-based morphometric analysis of skull baselines in Indian population

Abstract

Introduction:The study aims at providing an overview of morphometric measurements of the skull baselines in normal Indian population and compares these dimensions with those of other races and ethnicities. This study will help in defining “normal” baseline values for Indian population. It will also compare dimensions as measured on X-ray and computed tomography (CT) scan to assess the reliability of X-ray as a diagnostic modality for the assessment of the skull baselines in Indian population.Materials and Methods:Retrospective study with a sample size of 116 patients and duration of 30 months.Results:The mean value for distance between dens tip and Chamberlain line on CT was 0.498 mm and on X-ray was 0.528 mm and for the distance between dens tip and McGregor line on CT was 0.213 mm and on X-ray was 0.228 mm. The mean distance between the dens tip and McRae line was 4.67 1.69 mm on CT scan and 4.7 1.76 mm on X-ray.Conclusion:There was not a single patient in whom the dens tip crossed the McRae line. Any protrusion of the dens tip beyond the foramen magnum is abnormal. Hence, the McRae line is easiest to understand and remember. Furthermore, the Chamberlain and McGregor lines rely on identifying the hard palate, which may not be included in routine X-ray, CT, and magnetic resonance imaging studies depend on the field of view. Hence, we recommend the use of McRae line for screening purposes while evaluating pathologies of the craniovertebral junction. X-ray is a reliable diagnostic technique for assessing morphometry of the skull baselines in an emergency or rural setting if facility for CT scan is not available.

Analyzing variability of craniometric parameters using computed tomography scan in Indian population

“…18 Although male-female difference was found to be significant in the AADI and PADI parameters in the present study, seldom was any such difference recorded in the other studies. 5,13,[16][17][18][19]21,22 Similar to our study, Gupta et al, and Tanrisever et al, also found a significant difference between males and females when PADI was scrutinized (males had higher values). 18,19 Chen et al, found a statistical significance between males and females when AADI was examined (males had higher values).…”

“…21 Alike to the findings of Dash et al, and Marathe et al, our study also showed no differences between genders when examining dMR, dMG, dCL, and CCA. 16,17 After analyzing the data and comparing our results with that of the other races, we conclude that the data mentioned in the literature are not on par with what was observed in the present study. Although the values varied within the normal range, achieving nil statistical significance between the same and other populations may prove challenging.…”

“…16 Due to its superiority in speed, precision, quality, and ability to focus on bony structures, CT has become the predominant imaging modality as opposed to standard radiography and magnetic resonance imaging. 17 We hypothesize that different races will have different values and previously set standards cannot be applicable to all. Our 6 month -study yielded 240 CTs belonging to patients of Indian origin who had no CVJ abnormalities.…”

“…In previously performed studies using Indian patients, where sample sizes varied from 49 to 255, [16][17][18] several of the same parameters (which include dMR, dCL, dMG, AADI, PADI, and CCA) were measured. These studies have noted the dMR to be 4.67±1.69 17 with another study noting the same measurement to be 5.11±1.65. 16 We measured a value of 5.91±1.4.…”

“…Marathe et al, 17 also looked at dMG and dCL. When they analyzed dMG, they have found a mean of 0.213 with minimum and maximum values of -6.065 and 7.237, respectively.…”