A Diagnostic Biomarker for Cervical Myelopathy Based on Dynamic Magnetic Resonance Imaging

Jatta Berberat, PhD; Lukas Andereggen, MD; Philipp Gruber, MD; Oliver Hausmann, MD; Ali Reza Fathi, MD; Luca Remonda, MD

Disclosures

Spine. 2023;48(15):1041-1046.

Abstract and Introduction

Abstract

Study Design: Multicenter prospective observational study.

Objective: Diffusion tensor imaging in flexion extension improves the diagnosis of degenerative cervical myelopathy (DCM). We aimed to provide an imaging biomarker for the detection of DCM.

Summary of Background Data: DCM is the most common form of spinal cord dysfunction in adults; however, imaging surveillance for myelopathy remains poorly characterized.

Patients and Methods: Symptomatic DCM patients were examined in maximum neck flexion-extension and neutral positions in a 3T-magnetic resonance imaging scanner and allocated to 2 groups: (1) Patients with visible intramedullary hyperintensity (IHIS) on T2-weighted imaging (IHIS+, n = 10); and (2) Patients without IHIS (IHIS–, n = 11). Range of motion, space available for the spinal cord, apparent diffusion coefficient (ADC), axial diffusivity (AD), radial diffusivity, and fractional anisotropy were measured and compared between the neck positions and between the groups as well as between control (C2/3) and pathologic segments.

Results:Significant differences between the control level (C2/3) and pathologic segments were appreciated for the IHIS+ group at neutral neck position in AD; at flexion in ADC and AD; and at neck extension in ADC, AD, and fractional anisotropy values. For the IHIS– group, significant differences between the control level (C2/3) and pathologic segments were found only for ADC values in neck extension.

Table 1. Baseline Characteristics and Range of Motion
	IHIS+ (n = 10)	IHIS– (n = 11)
Age (yr), range	55.1 ± 11.2 (38–66)	58.7 ± 14.3 (37–81)
Sex (F); n, %	4 (40)	6 (55)
Weight (kg)	83.9 ± 14.9	79.2 ± 18.1
Height (cm)	169.6 ± 11.1	170.5 ± 10.8
BMI (kg/m²)	27.5± 5.3	27.4±5.1
Range of motion (°)	35.9 ± 5.9	37.8 ± 12.2
Angle normal position (°)	16.2 ± 4.2	14.8 ± 9.2
Angle flexion (°)	9.5 ± 3.5	10.1 ± 6.3
Angle extension (°)	25.3 ± 5.5	29.1 ± 7.3
mJOA score	15.5 ± 1.5	14.7±3.0
Muhle classification (0, 1, 2); n (%)*	0, 1 (43), 2 (57)	0 (27), 1 (55), 2 (18)

Values are presented as mean ± SD.
No statistically significant differences in the baseline characteristics were detected between the groups.
*Classification score: 0 = cord free; 1 = cord touched; 2 = cord compressed.
BMI indicates body mass index; IHIS, intramedullary hyperintensity; mJAO, modified Japanese Orthopedic Association.

Table 2. Diffusion Parameters of IHIS+ and IHIS– Patients
Neck Position	IHIS+ (n = 10)			IHIS– (n = 11)
Neck Position	Flexion	Neutral	Extension	Flexion	Neutral	Extension
AD (10^–6 mm²/s); C/23, control	1762 ± 195	2036 ± 211	1969 ± 372	1822 ± 310	2206 ± 547	1966 ± 376
AD (10^–6 mm²/s); pathologic level	2076 ± 418†	2433 ± 527*	2433 ± 712*	2004 ± 615	2427 ± 562	1996 ± 421
RD (10^–6 mm²/s); C/23, control	644 ± 136	727 ± 155§	782 ± 366	546 ± 167	542 ± 93§	642 ± 217
RD (10^–6 mm²/s); pathologic level	744 ± 143‡	714 ± 129‡	850 ± 176‡	607 ± 146‡	608 ± 100^‡	710 ± 147^‡
ADC (10^–6 mm²/s); C/23, control	1011 ± 139	1127 ± 80	124 ± 210	1054 ± 156	1090 ± 221	1066 ± 221
ADC (10^–6 mm²/s); pathologic level	1137 ± 195*	1303 ± 367	1353 ± 351*	1008 ± 316	1239 ± 306	1183 ± 129*
FA (10^–6 mm²/s); C/23, control	0.679 ± 0.101	0.596 ± 0.120	0.447 ± 0.052	0.682 ± 0.115	0.666 ± 0.085	0.707 ± 0.057
FA (10^–6 mm²/s); pathologic level	0.668 ± 0.095	0.648 ± 0.219	0.595 ± 0.073*	0.666 ± 0.113	0.661 ± 0.095	0.652 ± 0.089

*Statistically significant difference (P < 0.05) between affected and unaffected levels.
†Statistically significant difference (P < 0.01) between affected and unaffected levels.
‡Statistically significant difference (P < 0.05) between IHIS+ and IHIS– groups.
§Statistically significant difference (P < 0.01) between IHIS+ and IHIS– groups.
AD indicates axial diffusivity; ADC, apparent diffusion coefficient; FA, fractional anisotropy; IHIS, intramedullary hyperintensity; RD, radial diffusivity.