Increase in cerebral blood flow indicated by increased cerebral arterial area and pixel intensity on brain magnetic resonance angiogram following correction of cervical lordosis

Abstract

Context: Loss of cervical lordosis is associated with decreased vertebral artery hemodynamics.

Aim: The aim of this study is to evaluate cerebral blood flow changes on brain magnetic resonance angiogram (MRA) in patients with loss of cervical lordosis before and following correction of cervical lordosis.

Settings and design: This study is a retrospective consecutive case series of patients in a private practice.

Materials and methods: Cervical lordosis of seven patients (five females and two males, 28-58 years) was measured on lateral cervical radiographs ranging from -13.1° to 19.0° (ideal is -42.0°). Brain MRAs were analyzed for pixel intensities representing blood flow. Pixel intensity of the cerebral vasculature was quantified, and percentage change was determined.

Statistical analysis used: A Student's t-test established significance of the percentage change in cerebral blood flow between pre- and postcervical lordosis adjustment images. Regression analysis was performed. An a priori analysis determined correlation between cervical lordosis and change in MRA pixel intensity. The statistician was blinded to the cervical lordosis.

Results: Pixel intensity increased 23.0%-225.9%, and a Student's t-test determined that the increase was significant (P < 0.001). Regression analysis of the change in pixel intensity versus the cervical lordosis showed that as the deviation from a normal cervical lordosis increases, percentage change in pixel intensity on MRA decreases.

Conclusion: These results indicate that correction of cervical lordosis may be associated with an immediate increase in cerebral blood flow. Further studies are needed to confirm these findings and understand clinical implications.

Keywords: Brain magnetic resonance angiogram; Cervical Denneroll™; cerebral artery; cerebral blood flow; cervical lordosis.

Figure 1

Precervical lordosis adjustment radiograph. Lateral cervical images were analyzed using PostureRay® EMR software. Preradiographs show patients without the Cervical Denneroll™ Spinal Orthotic. Each image was analyzed for cervical lordosis measurements using the Harrison posterior tangent method. Red indicates the posterior aspect of the cervical vertebrae from C2 to C7. Green indicates ideal cervical lordosis from C2 to C7

Figure 2

Postcervical lordosis adjustment radiograph. Lateral cervical images were analyzed using PostureRay® EMR software. Postradiographs show the patients with the Cervical Denneroll™ Spinal Orthotic applied as a fulcrum to the cervical spine yielding an increase in cervical lordosis. Each image was analyzed for cervical lordosis measurements using the Harrison posterior tangent method. Red indicates the posterior aspect of the cervical vertebrae from C2 to C7. Green indicates ideal cervical lordosis from C2 to C7

Figure 3

Precervical lordosis adjustment magnetic resonance angiogram. Brain magnetic resonance angiogram images were analyzed using FIJI/ImageJ. Each image set was converted to an 8-bit TIF format and appropriate pixel thresholds were set for each image pair using the threshold tool. White indicates blood in cerebral vasculature

Figure 4

Precervical lordosis adjustment magnetic resonance angiogram pixel intensity analysis using FIJI/ImageJ. Pixel intensity of the cerebral vasculature was quantified by selecting the region of interest and quantifying pixel intensity. The threshold for the images was set so that the pixels indicating blood flow were compared. The quantity of red in the precervical lordosis adjustment magnetic resonance angiogram serves as a baseline for this patient. Red indicates pixels above threshold quantifying blood in cerebral vasculature. Yellow indicates the region of interest selected using the oval tool

Figure 5

Postcervical lordosis adjustment magnetic resonance angiogram. Brain magnetic resonance angiogram images were analyzed using FIJI/ImageJ. Each image set was converted to an 8-bit TIF format, and appropriate pixel thresholds were set for each image pair using the threshold tool. White indicates blood in cerebral vasculature

Figure 6

Postcervical lordosis adjustment magnetic resonance angiogram pixel intensity analysis using FIJI/ImageJ. Pixel intensity of the cerebral vasculature was quantified by selecting the region of interest and quantifying pixel intensity. The threshold for the images was set so that the pixels indicating blood flow were compared. The increased quantity of red in the postcervical lordosis adjustment magnetic resonance angiogram indicates increased blood volume after correction of cervical lordosis. Red indicates pixels above threshold quantifying blood in cerebral vasculature. Yellow indicates the region of interest selected using the oval tool

Figure 7

Change in pixel intensity versus absolute rotational angle (cervical lordosis) from C2 to C7 vertebrae. This linear regression analysis shows that as a deviation from a normal ARA increases, the percentage change in pixel intensity observed by magnetic resonance angiogram decreases. The R-squared value for this interaction is 0.3382, indicating that 33.8% of the possible change in observed pixel intensity can be attributed to the initial measured cervical lordosis. ARA C2–C7 is the absolute rotational angle measurement of cervical lordosis from C2 to C7 vertebrae (normal is 34° and ideal is 42°)