Can angled sagittal MRI of neural foramen combined with neurological findings determine the affected nerve root in cervical radiculopathy?

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1 Can angled sagittal MRI of neural foramen combined with neurological findings determine the affected nerve root in cervical radiculopathy? Masatoshi Morimoto, MD., Akihiro Nagamachi, MD. PhD., Kosuke Sugiura, MD. Department of Orthopedic Surgery Mitoyo General Hospital Kagawa, JAPAN

2 Angled Sagittal MRI A B A Angled Sagittal MRI B Sagittal MRI The cervical neural foramens are obliquely oriented relative to the axial plane. It is difficult to identify pathological changes of the cervical neural foramen using conventional sagittal MRI. Angled sagittal MRI perpendicular to the long axis of the cervical neural foramen provides anatomic details.

3 PURPOSE Angled sagittal MRI perpendicular to the long axis of the cervical neural foramen provides anatomic details, however, it is still difficult to determine the affected nerve root in patient with multiple foraminal lesions. In the same way, determination of the affected nerve root only from neurological findings is also difficult. The purpose of this study was to clarify whether angled sagittal MRI of neural foramen combined with neurological findings could determine the affected nerve root in cervical radiculopathy.

4 MATERIALS AND METHODS Thirty-six patients with cervical radiculopathy participated in this study. There were 17 males and 19 females and their mean age was 56 years. Cervical Disc Herniation 15 cases Cervical Spondylotic Radiculopathy 21 cases Neural foramens of the affected side from C2-3 to C7-Th1 were demonstrated. Angled sagittal MRI were evaluated independently by two spine surgeons blinded to neurological findings. A paucity of peripheral fat surrounding the nerve root and a foramen of diminished size on angled sagittal T2 weighted images were defined as foraminal stenosis. Normal Diminished Size Paucity of Peripheral Fat

5 METHODS One board-certificated spinal surgeon served as the neurological examiner. Two spinal surgeons tried to determine the affected nerve roots on the basis of angled sagittal MRI findings and neurological findings. Neurological Examination (estimation of the affected levels) Sensory: Light Touch Motor: Deep Tendon Reflex Scapulohumeral: C4, Deltoid: C5, Biceps: C5, C6, Brachioradialis: C6, C7, Triceps: C7 Motor: Manual Muscle Test Shoulder Elevation C4, Shoulder Abduction C5, Elbow Flexion C5, C6, Elbow Extension C7, Wrist Extension C6, C7, Wrist Flexion C8, Finger Extension C7, Finger Flexion C8, Finger Adduction Th1

6 RESULTS Number of Stenotic Foramen Observed on MRI Spinal Level Number of Stenotic Foramen Observer 1 Number of Stenotic Foramen Observer 2 Number of Agreed Stenotic Foramen Percent Agreement K Value Strength of Agreement C % C % 0.65 Substantial C % 0.65 Substantial C % 0.65 Substantial C % 0.59 Moderate C7-Th % 0.65 Substantial

7 Affected Nerve Roots Estimated From Neurological Examination Estimated Nerve Roots Number of Patients C3 0 C4 1 C5 3 C6 15 C7 9 C8 0 C5 or C6 2 C6 or C7 5 C5, C6 and C7 1 Total 36

8 Percentage of the Determined Nerve Roots by Both Angled Sagittal MRI and Neurological Examination NO. of Stenotic Foramen Observed on MRI NO. of Determined Affected Nerve roots Cervical Disc Herniation (n = 15) Single Level % Multiple Levels % Total % Cervical Spondylotic Radiculopathy (n = 21) Single Level % Multiple Levels % Total %

9 DISCUSSION AND CONCLUSION J. H. Shim et al. reported that sensitivity, specificity and accuracy of angled sagittal MRI in the diagnosis of foraminal herniated disc and stenosis. A total of 43 patients who had 50 level lesions. Seven cases included two levels lesions. There was no level documented by negative operation findings in these seven cases. Sensitivity, specificity and accuracy of foraminal herniated disc and stenosis were 96.7%, 95.0%, 96.0% and 96.3%, 95.7%, 96.0%, respectively. On the other hand, radiculopathy often arises from single lesion despite multiple foraminal herniated disc and stenosis exist. It is important to determine the affected nerve root that has responsibility for symptom to achieve good clinical outcome.

10 DISCUSSION AND CONCLUSION Angled sagittal MRI of neural foramen is more accurate imaging modality. However, we could determine the affected nerve root at 87% in cervical disc herniation and at 62% in cervical spondylotic radiculopathy even with detailed neurological examination in this study. Another modality, such as root block, should be considered to determine the affected nerve root in patients with multiple foraminal lesions.

11 Department of Orthopedic Surgery, Mitoyo General Hospital 708 Himehama, Toyohama, Kanonji, Kagawa, JAPAN TEL FAX M.Morimoto A. Nagamachi K. Sugiura

12 DISCLOSURE None of the authors has any potential conflict of interest.