New evaluation method using preoperative magnetic resonance imaging for cervical spondylotic myelopathy

A new method based on the score of preoperative magnetic resonance images (MRI) was devised to evaluate cervical spondylotic myelopathy and predict the results of cervical laminoplasty. On T1- and T2-weighted sagittal MRI, the intervertebral disc spaces at each level from the axis to the first thoracic spine were examined as to whether the anterior or posterior subarachnoid space would be maintained or not, and for the presence or absence of spinal cord deformity. The data were divided into six grades and rated, and the total score for all sites was regarded as the preoperative MRI cumulative score. In conclusion, our method was highly reliable and useful for a preoperative evaluation and prediction of results after cervical laminoplasty for cervical spondylotic myelopathy. Received: 18 December 2000     

Magnetic resonance imaging in the evaluation of a gunshot wound to the cervical spine

A patient in the second trimester of pregnancy sustained a gunshot wound of the upper cervical spine with a partial Brown-Séquard syndrome. The patient's condition was evaluated by conventional roentgenography, computed axial tomography (CT), and magnetic resonance imaging (MRI). The MRI alone clearly demonstrated the relationship of the bullet and the spinal cord, whereas the CT image was obliterated by metal artifacts. The bullet was removed from the spinal canal by a posterior approach with the patient in the sitting position and in skeletal cervical traction. The neurological status of the patient improved markedly after the surgery.     

Comparison of computed tomography myelography and magnetic resonance imaging in the evaluation of cervical spondylotic myelopathy and radiculopathy.

STUDY DESIGN: A cross-sectional retrospective radiologic study. OBJECTIVES: To establish concordance rates between interpretations of computed tomography myelography and magnetic resonance imaging in patients with degenerative cervical spine disease. SUMMARY OF BACKGROUND DATA: Observed discrepancies in interpretation of computed tomography myelography and magnetic resonance imaging question the reliability of comparisons between these two methods. METHODS: This study blindly and randomly evaluated cervical computed tomography myelography and magnetic resonance imaging in 20 patients referred for clinically diagnosed cervical spondylotic radiculopathy, myelopathy, or both. The discovertebral joints, facet joints, lateral recesses, cord size, spinal canal, and neural foramina also were evaluated with graded scales. All results were subjected to the kappa statistic for strength of agreement. RESULTS: Agreement for interpretation of the discovertebral junction occurred in 144 of 240 sites (60%), indicating only moderately good intermethod concordance (kappa = 0.44). Intermethod agreement on the characterization of facet joint disease was only moderately good (143 of 160 sites; 89.4%; kappa = 0.52), and on characterization of lateral recess disease was poor (125 of 160 sites; 78.1%; kappa = 0.20). On degree of spinal canal compromise, there was agreement within one grade in 199 of 240 sites (82.9%; kappa = 0.42). Intermethod agreement on neural foraminal encroachment and cord size was only moderately good (kappa = 0.42 and 0.46, respectively). Computed tomography myelography tended to upgrade the spinal canal narrowing and neural foraminal encroachment. CONCLUSIONS: For most parameters of interpretation, the degree of concordance between computed tomography myelography and magnetic resonance imaging is only moderately good, with discrepancies noted especially in the differentiation of disc and bony pathology. These methods should be viewed as complementary studies.     

Magnetic resonance imaging and cervical spondylotic myelopathy

Nineteen patients were examined for cervical spondylotic myelopathy with magnetic resonance imaging. Pre- and postoperative magnetic resonance scans were obtained in most cases. Surgical confirmation of the pathological condition was obtained for all 19 patients. On the T2-weighted scans, there was increased signal intensity within the spinal cord at the point of maximal compression. The exact cause of the increased signal intensity on the T2-weighted images is not known, but is suspected to represent edema, inflammation, vascular ischemia, myelomalacia, or gliosis. The increased signal intensity diminished postoperatively in the patients who improved clinically, and remained the same or increased in those whose conditions remained unchanged or worsened after decompression. The authors suggest that these T2-weighted images carry prognostic significance.     

Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms

Purpose: Contrast arteriography (CA) is a useful but invasive technique for the preoperative evaluation of patients with abdominal aortic aneurysms (AAA). To evaluate the use of magnetic resonance arteriography (MRA) as a preoperative study we prospectively studied 38 patients undergoing AAA repair.Methods: All patients underwent biplane CA and MRA with use of a gadolinium-enhanced technique. Radiographic studies were then independently evaluated by blinded radiologists for anatomic findings with CA used as the standard. Studies were then independently evaluated by blinded vascular surgeons, and a surgical plan was made.Results: With CA and intraoperative findings as the standards, MRA proved highly accurate in the determination of multiple key anatomic elements. The proximal extent of aneurysmal disease was correctly predicted in 87% (33/38) patients. Significant iliofemoral occlusive disease was identified with a sensitivity of 83% (5/6). Iliac or femoral aneurysms were detected with a sensitivity of 79% (22/28) and specificity of 86% (41/48). Significant renal artery stenosis was detected with a sensitivity of 71% (12/17) and a specificity of 99% (72/73). Accessory renal arteries were correctly identified in 71% (12/17). Surgeon evaluators correctly predicted the proximal cross-clamp site in 87% (33/38) of patients with use of MRA as compared with the actual operative conduct. Proximal anastomotic sites were correctly predicted in 95% (36/38) with MRA and 97% (37/38) with CA. Renal revascularization was predicted by MRA with a sensitivity of 91% (10/11) and specificity of 100% (65/65). The use of bifurcated aortic prostheses was correctly predicted by MRA in 75% (12/16), which was similar to that predicted by CA (81%, 13/16).Conclusions: MRA can provide preoperative anatomic information that is equivalent to CA for surgical planning. Because of favorable cost and patient safety considerations MRA will assume increasing importance in the preoperative evaluation of AAA. (J VASC SURG 1995;21:891-9.)     

Magnetic resonance imaging in the evaluation of infantile torticollis

This retrospective study assessed the use of magnetic resonance imaging (MRI) in 58 infants with infantile torticollis. Eighteen patients had nonmuscular causes of torticollis (group 1); MRI identified lesions in 16 patients. Of 40 patients with a diagnosis of congenital muscular torticollis (group 2), 28 had a normal MRI. Five patients had asymmetry of the sternocleidomastoid without noticeable signal changes. Seven patients showd evidence of fibromatosis colli. Asymmetry of the posterolateral skull consistent with plagiocephaly was common. Magnetic resonance imaging did not alter treatment of group 2. Findings of compartment syndrome of sternocleidomastoid were inconsistent. Magnetic resonance imaging is not recommended for asymptomatic patients with infantile torticollis.     

Magnetic resonance imaging in the evaluation of prostate cancer

Summary Advantages of magnetic resonance imaging (MRI) in the study of prostatic disease include a precise anatomical display in multiple planes, superb contrast resolution, and differential physicochemical characteristics that are obtained without known toxicity. In practice, however, MRI has not been shown to differentiate consistently between normal and abnormal prostatic tissue. Although normal prostatic and periprostatic anatomy is clearly defined in T₁-weighted images, controversy persists as to the precise differential characteristics of inflammatory and neoplastic disease within the prostate. Thus, MRI is not presently adequate for prostate cancer screening. MRI has been shown to be superior to computerized axial tomography (CAT) for pelvic staging of prostate cancer; however, comparative studies involving other modalities with precise histologic confirmation are limited and the improvement reported is modest. There is some evidence that MRI may be helpful in the detection of prostate cancer metastatic to bone, but, again, information is limited. Substantial advances in MRI techniques such as optimal pulse sequencing, surface coils, and, possibly, paramagnetic contrast agents will be required to secure a role for MRI in prostate cancer evaluation.     

A comparison of magnetic resonance imaging and neurophysiological studies in the assessment of cervical radiculopathy

Neurophysiological studies (NPS) are often used by both neurosurgeons and neurologists to supplement neuroimaging findings in the diagnosis of cervical radiculopathy and in operative decision-making. The aim of this study was to assess whether nerve conduction and electromyographic studies added significant information to that obtained from high resolution MRI to warrant routine use. Over the 10-year period (1991-2001), we identified 48 patients who underwent both preoperative NPS and MRI for cervical radiculopathy. Sensitivity of MRI and NPS for diagnosing cervical radiculopathy was 93 and 42%, respectively. Whilst the positive predictive values for MRI and NPS were similar (91% versus 86%), the former had a higher negative predictive value (25% versus 7%). In only one case was the decision to operate based on NPS despite a negative MRI. We therefore suggest that in patients with clinical and MRI evidence of cervical radiculopathy, NPS has limited additional diagnostic value.     

磁共振成像对膀胱肿瘤分期的评价

从１９９２年８月至１９９４年８月，采用ＭＲ、ＣＴ、经尿道腔内超志和经腹部超声对２７例膀胱肿瘤患者的３３个肿瘤进行了检查，并分别与术后病理分期结果进行比较。ＭＲ判断肿瘤分期的准确率为９２．５％，ＣＴ为７３．３％，经尿道腔内超声为８８．９％，经腹部超声为６０．０％。结果认为，经腹部超声可用于对膀胱肿瘤的筛选检查，判断肿瘤分期不可靠，经尿道腔内超声对限于膀胱壁以内的肿瘤分期是准确的，而ＣＴ对浸润到膀胱壁     

磁共振波谱成像(MRSI)应用于前列腺癌的评估

本文通过MRSI探讨前列腺病变组织中特定代谢产物的变化,评估对前列腺癌的诊断,定位和分期等方面的意义.     

Magnetic resonance imaging of upper cervical disorders in rheumatoid arthritis

Upper cervical spine was examined with magnetic resonance imaging (MRI) and conventional roentgenograms in 55 patients with rheumatoid arthritis. The MRI findings were compared with various values determined in roentgenograms: the atlanto-dental interval (ADI), the space available for the spinal cord (SAC), and the Ranawat and Redlund-Johnell values. In patients with vertical settling (VS), MRI showed medullary compression in all those with abnormal Redlund-Johnell values and Ranawat values of 7 mm or less. In patients with anterior atlanto-axial subluxation, compression of the upper cervical cord was observed in all patients with SAC of 13 mm or less and many of those with ADI of 8 mm or greater. This study indicated that medullary compression can be estimated by these values determined in roentgenograms of the cervical spine.     

Magnetic resonance imaging versus angiography in the preoperative assessment of abdominal aortic aneurysms

Magnetic resonance is a cost-effective imaging tool in the preoperative evaluation of abdominal aortic aneurysm, and yields more clinically relevant information than ultrasonography and computerized tomography. Magnetic resonance imaging has advantages over angiography in that is costs substantially less, is noninvasive, and reconstructs images in multiple planes. By utilizing multiplanar imaging, magnetic resonance imaging yields more information than angiography. The position of the left renal vein is imaged only by magnetic resonance, as is the origin of the superior mesenteric artery. Angiography remains important in patients with associated occlusive disease and claudication. The use of magnetic resonance in the emergent setting is limited at this time.     

Magnetic resonance angiography for preoperative evaluation of potential kidney donors

BACKGROUND: Careful evaluation of the renovascular anatomy for living kidney donors is essential to optimize donor and recipient outcomes. Arteriography has been the standard for delineating the renovascular anatomy. However, this procedure is invasive. Magnetic resonance angiography (MRA) is an attractive, noninvasive alternative. The aim of this study was to evaluate the accuracy of MRA in potential living kidney donors. METHODS: A retrospective comparison of the preoperative MRA results with the intraoperative anatomy was performed in 189 living kidney donors. RESULTS: MRA interpretations correctly identified the vascular anatomy of the donor kidneys in 173 donors (91.5%). In the remaining 16 patients (8.5%), the MRA interpretation was inaccurate. In 10 patients, the MRA reported fewer arteries than the number encountered during the donor operation, whereas in six patients MRA reported more arteries than what found during operation. In seven patients, MRA supplied additional important anatomical information, including kidney size disparity, the presence of nephrolithiasis, the presence of a renal cyst, and renal artery stenosis. All kidneys were successfully transplanted. The misinterpretation of the MRA did not adversely affect the recipient outcome. CONCLUSION: The noninvasive MRA evaluation of donor renovascular anatomy is an acceptable substitute for traditional angiography.     

Magnetic resonance imaging and preoperative evaluation of cancer of the kidney. The results apropos of 60 cases

Sixty renal carcinomas confirmed at surgery or autopsy were studied. Capsular effraction, present in 17 cases, was well assessed in 8 cases, under staged in 8 cases and over staged in 5 cases (sensitivity 47%, specificity 88%). Renal vein involvement was present in 11 cases. In 8 of these 11 cases, a thrombus was present in the inferior vena cava. MRI detected a thrombus in the renal veins in 10/11 cases and in 7/8 cases of caval invasion. The false negative case was due to a huge right upper pole tumor laminating the inferior vena cava. The false positive case was due to an enlarged lymph node compressing the inferior vena cava. Cranial extension of the thrombus was well assessed in 6 of the 7 cases. One thrombus in the right atrium was missed. Lymph node involvement was present in 10 cases and correctly diagnosed by MRI in 7 cases. Three false negative cases were noted, because of microscopic invasion in non enlarged lymph nodes. Adjacent organ invasion, present in 2 cases, was detected in 1 case of liver invasion. Initial results of MRI seem very promising and at present, the best indications of MRI in pre-operative evaluation of a renal carcinoma are assessment of caval extension and spread to adjacent organs in patients with large tumors.