Detection of Surgery-related Spinal Cerebrospinal Fluid Leakage Using Magnetic Resonance Myelography

Detection of cerebrospinal fluid leakage or exact localization of leakage site after spinal surgery is difficult on conventional imaging studies. We report two patients with surgery-related spinal CSF leakage detected on magnetic resonance (MR) myelography. They presented with severe headache after spinal surgeries, lumbar discectomy and excision of spinal meningioma, respectively. The sites of spinal CSF leakage in the patients were detected accurately on MR myelography, and the patients recovered from the postoperative CSF leakage after being treated with an epidural blood patch or reoperation. MR myelography may be effective in demonstrating the exact site of surgery-related spinal CSF leakage.

Comparative Study of Lumbar Magnetic Resonance Imaging and Myelography in Young Soldiers with Herniated Lumbar Disc

OBJECTIVE: This study was undertaken to compare the diagnostic performances of magnetic resonance imaging (MRI), MR myelography (MRM) and myelography in young soldiers with a herniated lumbar disc (HLD). METHODS: Sixty-five male soldiers with HLD comprised the study cohort. A visual analogue scale for low back pain (VAS-LBP), VAS for leg radiating pain (VAS-LP), and Oswestry disability index (ODI) were applied. Lumbar MR, MRM, and myelographic findings were checked and evaluated by four independent radiologists, respectively. Each radiologist was asked to score (1 to 5) the degree of disc protrusion and nerve root compression using modified grading systems devised by the North American Spine Society and Pfirrmann and the physical examination rules for conscription in the Republic of Korea. Correlated coefficients between clinical and radiological factors were calculated. Interpretational reproducibility between MRI and myelography by four bases were calculated and compared. RESULTS: Mean patient age was 20.5 +/- 1.1. Mean VAS-LBP and VAS-LP were 6.7 +/- 1.6 and 7.4 +/- 1.7, respectively. Mean ODI was 48.0 +/- 16.2%. Mean MRI, MRM, and myelography scores were 3.3 +/- 0.9, 3.5 +/- 1.0, and 3.9 +/- 1.1, respectively. All scores of diagnostic performances were significantly correlated (p < 0.05). However, none of these scores reflected the severity of patients' symptoms. There was no statistical difference of interpretational reproducibility between MRI and myelography. CONCLUSION: Although MRI and myelography are based on different principles, they produce similar interpretational reproducibility in young soldiers with a HLD. However, these modalities do not reflect the severity of symptoms.

Morphologic Changes of L5 Root at Coronal Source Images of MR Myelography in Cases of Foraminal or Extraforaminal Compression

OBJECTIVE: Two findings easily found at coronal source images of MR myelography (MRM) were evaluated : dorsal root ganglion (DRG) swelling and running course abnormality (RCA) of L5 exiting root at foramen or extraforamen. We tried to find the sensitivity of each finding when root was compressed. METHODS: From 2004 July to 2006, one hundred and ten patients underwent one side paraspinal decompression for their L5 root foraminal or extraforaminal compression at L5-S1 level. All kinds of conservative treatments failed to improve leg symptom for several months. Before surgery, MRI, CT and MRM were done. Retrospective radiologic analysis for their preoperative MRM coronal source images was done to specify root compression sites and L5 root morphologic changes. RESULTS: DRG swelling was found in 66 (60%) of 110 patients. DRG swelling has statistically valuable meaning in foraminal root compression (chi-square test, p < 0.0001). Seventy-two (66%) in 110 patients showed abnormal alteration of running course. Abnormal running course has statistically valuable meaning in foraminal or extraforaminal root compression (chi-square test, p < 0.0001). CONCLUSION: Three-dimensional MRM provides precise thin sliced coronal images which are most close to real operative views. DRG swelling and running course abnormality of L5 exiting root are two useful findings in diagnosing L5 root compression at L5-S1 foramen or extraforamen. MRM is thought to provide additional diagnostic accuracy expecially in L5-S1 foraminal and extraforaminal area.

Usefullness of Routine MR-Myelography at MRI for Multiple Lumbar Stenosis / 대한정형외과학회잡지

PURPOSE: To determine if MR myelography (MRM) improves the interpretation of the severity of stenosis in patients with a multi-level lumbar stenosis. MATERIALS AND METHODS: Among the patients referred for MRI with MRM prospectively, 100 patients over 50 years old with multiple lumbar stenosis were enrolled in this study. The most severe stenotic level and the degree of stenosis at that level according to the extent of the remaining subarachnoidal space (1: normal to 50%, 2: over 50% but not a total block, 3: total block) were evaluated in a blinded manner by two observers. Conventional MRI (class A), MRM (class B) and MRI+MRM (class C) was evaluated independently and the interobserver and intraobserver reliability were assessed. RESULTS: In the selection of the most severe level and degree of stenosis, both observers showed a higher level of consensus with classes B and C than classes A and C. The interobserver k average values for the selection of the most severe level in classes A, B and C were 0.649, 0.782 and 0.832, respectively. In terms of the degree of stenosis, the average in classes A, B and C were 0.727, 0.771 and 0.784, respectively. The intraobserver k values for the above two items were the highest in class (B), followed by (C) and (A) in all observers and within the range of "almost perfect" (0.81< or =k< or =1) except for the selection of the level of one observer in clause A. CONCLUSION: MRM when used in routine practice can help improve the observer reliability in assessing the severity of stenosis in multiple lumbar stenosis.

A comparison of MR myelography of brachial plexus injury with CT myelography and conventional myelography.

The purpose of study is to assess the accuracy of magnetic resonance myelography (MRM) of the cervical spine in patients with preganglionic Brachial Plexus Injury (BPI) by using CT myelography as the gold standard and comparing this with routine conventional myelography. Patients with a clinically diagnosis of Brachial plexus Injury were studied (9 males, 1 female, aged 16 - 42 years old) [mean age = 25.4 years old]). All patients had undergone clinical evaluation by an orthopedic surgeon and five patients had had additional somatosensory evoked potentials (SEP) performed. All patients were investigated by conventional myelography, computed tomography myelography (CTM) and magnetic resonance myelography (MRM). We used CT myelography as the gold standard and the accuracy of MRM and myelography were assessed in relative to this. The sensitivity in detecting a pseudomeningocele by MRM is 100% and the sensitivity in detecting nerve root abnormality is 90% at the level of the C5, C6 roots and 100% for the C7, C8, T1 roots. MR Myelography had many advantages over conventional and CT myelography which include the absence of radiation and the lack of need for intrathecal injection of contrast medium.