The correlation between magnetic resonance imaging and the operative and clinical findings after lumbar microdiscectomy

Fifty-four consecutive patients were studied prospectively with magnetic resonance imaging before microdiscectomy, and the findings correlated with clinical symptoms before and after operation. A sequestrated fragment was found in 59% of cases, a subligamentous disc sequestration in 25% and a disc protrusion in 16%. The levels operated on were L4/5 – 36%, L5/S1 – 62.5%, and one at L3/4; 71% were laterally placed, 10% lay intraforaminal and 10% medial. The diameter of the protrusion was 4 mm to 13 mm for the craniocaudal extension, and 5 mm to 18 mm for the anteroposterior extension. No correlation could be found between a neurological deficit and the size of the prolapse. A positive correlation was present between the increasing degree of canal obstruction and the degree of disc degeneration determined by imaging for extrusions, subligamentous disc sequestrations and free sequestrations. Nerve root inflammation and enlargement was seen in 36% of the images, corresponding to an operative finding of 32%. Magnetic resonance imaging is a helpful preoperative diagnostic investigation which shows structural changes in the disc and the correct localisation and size of the disc sequestration, but there was no correlation between the imaging findings and the clinical symptoms.

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Résumé. Dans une étude prospective 54 patients d’un age moyen de 41 ans ont été examinés avant une microdiscectomie au moyen d’un protocole IRM standardisé. Les résultats de l’IRM ont été mis en corrélation avec les symptomes cliniques avant et après chirurgie et les constatations operatoires. 59% des patients avaient un fragment libre, 25% un séquestre sous-ligamentaire du disque et 16% une protrusion du disque au niveau L4/5 (36%) ou L5/S1 (62%) et aussi une au niveau L3/4. 71% de celles ci étaient situées médiolatéralement, 10% latéralement ou intraforaminal et 10% seulement avaient une localisation médiale. Les diamètres de la protrusion discale variaient de 4 à 13 mm pour l’extension craniocaudale et de 5 à 18 mm pour l’extension antério-postérieure. Aucune corrélation entre un déficit neurologique et la taille du prolapse discal ont été trouvée. Une corrélation existe entre le degré d’augmentation de l’obstruction du canal et le degré de la dégénération du disque déterminéà l’aide du l’IRM pour les extrusions, les séquestres sous-ligamentaires et les séquestres libres. L’inflammation et l’agrandissement de la racine du nerf se montraient dans 36% des IRM correspondant à 32% intra-opèra- toires. Le IRM est une technique diagnostique importante préoperative pour permettre la localisation correcte, et pour une prévision de la grandeur de la séquestration disquaire. Il n’existe pas de corrélation entre le IRM et les symptomes cliniques.

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Accepted: 5 September 1997     

"Moustache" appearance in craniopharyngiomas: unique magnetic resonance imaging and computed tomographic findings of perifocal edema

This report describes two cases of craniopharyngioma with perifocal edema. In both patients, computed tomography and magnetic resonance imaging (MRI) revealed that the tumors occupied the suprasellar cistern, invaginated the floor of the 3rd ventricle and were tightly adherent to the ventricular walls. The intraventricular portions of the tumors were cystic, containing protein-rich fluid as suggested by MRI and confirmed by operative findings. There was perifocal edema in the hypothalamus adjacent to the intraventricular tumor, the optic tracts, and the posterior limbs of the internal capsules, resembling the shape of a moustache on axial computed tomographic and MRI scans. The perifocal edema subsided after treatment of the intraventricular tumor by surgical resection or radiation therapy. The "moustache" appearance seems a unique, characteristic feature of perifocal edema, which is observed infrequently with certain craniopharyngiomas.     

Polyorchidism: sonographic and magnetic resonance imaging findings

Polyorchidism is a rare anomaly and frequently associated with criptorchidism, inguinal hernia and testicular torsion. It is also reported as increased risk of testicular malignancy. We report a case of 23 year old man with left supernumerary testis in the left hemiscrotum. He presented with painless mass in his left hemiscrotum. Normal physical examination and laboratory tests including spermiogram were examined. Both ultrasound and MRI examinations revealed polyorchidism without malignancy or any other concomitant features. In most cases sonography alone is diagnostic. MRI may provide additional information in complicated cases of polyorchidism. Conservative treatment with sonographic follow-up is the choice of treatment in uncomplicated cases.Polyorchidism is an anomaly of the genitourinary tract, with almost 200 cases reported in the literature; it refers to the presence of more than two testes.¹ This congenital anomaly typically causes no impairments, but it is frequently associated with maldescended testis, inguinal hernia and testicular torsion. Reports slso show an increased risk of testicular malignancy in the presence of polyorchidism.² This paper presents a case of polyorchidism without any associated anomaly in a 23-year-old man.     

A correlation between magnetic resonance imaging and electrophysiological findings in cervical spondylotic myelopathy.

STUDY DESIGN: Correlation between compressed spinal cords on magnetic resonance imaging (MRI) and electrophysiological findings in cervical spondylotic myelopathy patients. OBJECTIVE: To clarify the correlation between spinal-cord-evoked potentials and MRI measurements of compressed spinal cords in patients with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: Compression of the spinal cord does not always cause clinical symptoms and it is difficult to infer the degree of dysfunction of the spinal cord from MRI findings. METHODS: Seventeen patients with cervical spondylotic myelopathy were examined with MRI and spinal-cord-evoked potentials before surgery. Using abnormality in spinal-cord-evoked potentials as indicators of spinal cord morphology, spinal-cord transverse area and compression ratios (central and 1/4-lateral) were measured on T1-weighted axial imaging. The correlations between these dimensions and electrophysiological findings were investigated. RESULTS: The mean preoperative transverse area of the spinal cord was 47.13 mm2.The mean preoperative central compression ratio of the spinal cord was 34.4%. The mean preoperative 1/4-lateral compression ratio of the spinal cord was 27.5%. A correlation (Spearman r=0.65, P < 0.01) was observed between the 1/4-lateral compression ratio of the spinal cord and the amplitude ratio of spinal-cord-evoked potentials after electric stimulation of the brain (Br(E)-SCEPs). CONCLUSIONS: The preoperative 1/4-lateral compression ratio of the spinal cord was found to reflect the degree of dysfunction of the corticospinal tracts.     

Comparison of magnetic resonance imaging with operative findings in acute traumatic dislocations of the adult knee

OBJECTIVES: To compare magnetic resonance imaging (MRI) with examination under anesthesia and with surgical findings in evaluating soft tissue injuries in acute traumatic knee dislocations in adults. DESIGN: Retrospective analysis. SETTING: Level I trauma center. PATIENTS: For a single surgeon, all patients who underwent MRI before surgical treatment for knee dislocations (ten individuals). INTERVENTION: Incompetent ligaments were repaired or reconstructed. MAIN OUTCOME MEASUREMENTS: MRI of knee dislocations was compared with clinical examination under anesthesia and with intraoperative findings at arthrotomy in ten cases. Pertinent positive and negative findings were recorded, and accuracy, sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: Two mid-grade sprains of the anterior cruciate ligament were erroneously read as complete tears. One rupture or avulsion of each the biceps tendon, the lateral collateral ligament, and the posterolateral and posteromedial corners were considered intact on MRI. The MRI studies erroneously identified tears of the lateral collateral ligament and medial meniscus in one case each. Otherwise, the study was highly accurate. CONCLUSIONS: MRI is useful for defining the presence of ligamentous injuries in knee dislocations; however, clinical examination under anesthesia is more accurate.     

Is there a role for diskography in the era of magnetic resonance imaging? Prospective correlation and quantitative analysis of computed tomography-diskography, magnetic resonance imaging, and surgical findings.

We herein report the results of a prospective study to define the role of diskography in the diagnosis of low back pain in an emerging era of magnetic resonance imaging (MRI). The study involved 32 patients (78 disks) with a clinical diagnosis of lumbar disk herniation; all were studied by computed tomography-diskography (CT-D), and 25 (51 disks) were also examined using MRI. The disks were graded on these studies according to a staging scheme modified from Modic. Ten of the patients (13 disks) having both CT-D and MRI underwent exploratory surgery, and the staging at surgery served as the standard against which the evaluative studies were judged. Surgical staging was compatible with the CT-D and MRI results in five disks, while in another five disks it was compatible only with the CT-D results. In the remaining three disks, both CT-D and MRI misidentified the stages. In six disks, CT-D more accurately defined the stage of disease than did MRI, whereas MRI was more precise than CT-D in only one disk. While having documented the value of CT-D as a source of information, particularly when surgery is contemplated, and as an effective means of staging disk herniation, we recommend MRI as the ideal screening test for lumbar radiculopathy and low back pain, reserving diskography for problematic cases.     

Central spinal cord injury: magnetic resonance imaging confirmation and operative considerations

A case of central cervical spinal cord injury, confirmed by magnetic resonance imaging (MRI) and treated by myelotomy, is presented. After recovering well from his central cord syndrome and walking with assistance, the patient developed a rapidly progressive myelopathy beginning 2 months after injury. His main injury localized clinically to the C8, T1 level; but central cord abnormalities were identified 3 months after injury at the C6 level by MRI: a high signal intensity on the proton density sequence and a low-signal intensity on the T1-weighted sequence. At operation 41/2 months after his injury and 1 month after complete paraplegia, a myelotomy at C6 failed to reveal any cavity (syrinx) but instead disclosed only intense gliosis inside a slightly atrophic spinal cord. Rapid clinical improvement ensued. Secondary syringomyelia may be an endstage condition after spinal cord insults that trigger a progressive, pathophysiological reaction leading to central cord necrosis. In selected cases, myelotomy may interrupt this MRI-identified, nosogenic process before cavitation has occurred.     

Primary localized amyloidosis of urethra: magnetic resonance imaging findings

Amyloidosis of the urogenital tract is relatively rare. We experienced a case of primary localized amyloidosis of the urethra and report its characteristics on magnetic resonance imaging. In our case, the lesion exhibited low signal intensity on T1-weighted and T2-weighted images and was well-enhanced on gadolinium-enhanced T1-weighted images. The gross appearance on cystoscopic examination suggested urethral malignancy but the low signal intensity is atypical for malignant tissue. Because magnetic resonance imaging clearly demonstrated the local extent and depth of the lesion, it was useful in making our decision to perform conservative resection.     

Reliability of gadolinium-enhanced magnetic resonance imaging findings and their correlation with clinical outcome in patients with sciatica

Background contextGadolinium-enhanced magnetic resonance imaging (Gd-MRI) is often performed in the evaluation of patients with persistent sciatica after lumbar disc surgery. However, correlation between enhancement and clinical findings is debated, and limited data are available regarding the reliability of enhancement findings.PurposeTo evaluate the reliability of Gd-MRI findings and their correlation with clinical findings in patients with sciatica.Study designProspective observational evaluation of patients who were enrolled in a randomized trial with 1-year follow-up.Patients samplePatients with 6- to 12-week sciatica, who participated in a multicentre randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. In total 204 patients underwent Gd-MRI at baseline and after 1 year.Outcome measuresPatients were assessed by means of the Roland Disability Questionnaire (RDQ) for sciatica, visual analog scale (VAS) for leg pain, and patient-reported perceived recovery at 1 year. Kappa coefficients were used to assess interobserver reliability.MethodsIn total, 204 patients underwent Gd-MRI at baseline and after 1 year. Magnetic resonance imaging findings were correlated to the outcome measures using the Mann-Whitney U test for continuous data and Fisher exact tests for categorical data.ResultsPoor-to-moderate agreement was observed regarding Gd enhancement of the herniated disc and compressed nerve root (kappa<0.41), which was in contrast with excellent interobserver agreement of the disc level of the herniated disc and compressed nerve root (kappa>0.95). Of the 59 patients with an enhancing herniated disc at 1 year, 86% reported recovery compared with 100% of the 12 patients with nonenhancing herniated discs (p=.34). Of the 12 patients with enhancement of the most affected nerve root at 1 year, 83% reported recovery compared with 85% of the 192 patients with no enhancement (p=.69). Patients with and without enhancing herniated discs or nerve roots at 1 year reported comparable outcomes on RDQ and VAS-leg pain.ConclusionsReliability of Gd-MRI findings was poor-to-moderate and no correlation was observed between enhancement and clinical findings at 1-year follow-up.     

Evaluation of the painful shoulder. A prospective comparison of magnetic resonance imaging, computerized tomographic arthrography, ultrasonography, and operative findings

Twenty-one patients who had had pain in the shoulder for more than three months were evaluated with ultrasonography and magnetic resonance imaging followed by computerized tomographic arthrography. The results of the imaging studies were then compared with the operative findings. Magnetic resonance imaging was found to be the most useful modality for establishment of the etiology of pain in the shoulder due to disease of the rotator cuff, instability associated with abnormality of the glenoid labrum, subacromial impingement, stenosis of the coracoacromial arch, and osteoarthrosis of either the glenohumeral or the acromioclavicular joint. The accuracy of magnetic resonance imaging was found to depend on both the operator and the technique and was decreased in extremely obese patients, due to difficulties in positioning, and in patients who had had a previous operation. Magnetic resonance imaging was more accurate than either computerized tomographic arthrography or ultrasonography in identifying partial-thickness tears (intrasubstance changes in the rotator cuff). Magnetic resonance imaging provided the same level of accuracy as computerized tomographic arthrography in the detection of abnormalities of the glenoid labrum.     

Neurobehavioral functioning and magnetic resonance imaging findings in young boxers

In a prospective investigation of neurobehavioral functioning in young boxers, 13 pugilists and 13 matched control subjects underwent tests of attention, information-processing rate, memory, and visuomotor coordination and speed. The results disclosed more proficient verbal learning in the control subjects, whereas delayed recall and other measurements of memory did not differ between the two groups. Reaction time was faster in the boxers than in the control subjects, but no other differences were significant. Ten subjects in each group were retested 6 months later and exhibited improvement in their neuropsychological performance as compared to baseline measurements. However, there were no differences in scores between the boxers and the control subjects at the follow-up examination or in the magnitude of improvement from baseline values. Magnetic resonance imaging, which was performed in nine of the boxers, disclosed normal findings.     

Radiologic assessment of tumor and the carotid artery: correlation of magnetic resonance imaging, ultrasound, and computed tomography with surgical findings

Carotid artery fixation is an extremely poor prognostic sign in squamous cell carcinoma of the head and neck. Methods more precise than physical exam are necessary to determine whether a neck dissection is sufficient, to exclude patients from surgery, or to plan a carotid artery resection. Thirty-three patients with a suspicion of carotid wall attachment by physical examination or computed tomography (CT) were further evaluated by magnetic resonance imaging (MRI) and ultrasound (US). The criterion for possible carotid involvement on CT was effacement of greater than 25% of the circumference of the artery. On MRI, the criterion that we proposed was any loss of the fascial plane around the internal or common carotid artery. This was considered effacement of the carotid artery wall. For US, the criterion we used was the loss of the echogeneity along the carotid wall. Histopathological correlation was available in 23 patients (24 necks) who either underwent surgery or necropsy (1 patient); 11 patients were felt not to be surgical candidates or declined surgery, though 1 of these 11 patients did undergo surgical resection after radiotherapy. MRI accurately predicted an uninvolved carotid artery in 13 of 15 cases; US accurately predicted an uninvolved carotid artery in 15 of 20 cases. Demonstration by either MRI or US that the carotid artery is free of tumor had a high degree of reliability. Both US and MRI appear superior to CT and physical examination in assessing the carotid wall in suspicious cases. Individually and in combination, MRI and US offer advantages in selecting patients for possible surgery when the issue of carotid artery fixation is raised.     

Diabetic fibrous mastopathy: dynamic contrast-enhanced magnetic resonance imaging findings

Diabetic fibrous mastopathy (DFM) is an uncommon lesion that may clinically mimic breast carcinoma. Routine mammographic and ultrasonographic features of this disease also mimic the those of malignant disease, making an accurate preoperative diagnosis difficult. Dynamic contrast-enhanced magnetic resonance imaging (MRI), however, reveals a homogeneous low-enhancement with a gradual and progressive course without a washout. A corresponding time intensity curve is related to benign lesions of low vascularity, and by being a potential criterion for making a differentiation between DFM and malignant processes, spares patients from excisional biopsy.     

Pituitary apoplexy: correlation between magnetic resonance imaging and histopathological results

OBJECT: The aim of this study was to correlate the magnetic resonance (MR) imaging findings in pituitary apoplexy with histopathological results and determine whether the histopathology influences clinical presentation and outcome. METHODS: The records of 36 patients with histologically confirmed pituitary apoplexy, who were treated surgically at the University of Virginia Health System between 1996 and 2006, were retrospectively reviewed. The MR images were divided into 3 groups: 1) infarction alone; 2) hemorrhage with or without infarction; and 3) tumor only with no evidence of apoplexy. The histological examination was divided into infarction alone or hemorrhagic infarction/hemorrhage. The MR imaging findings were then correlated with the histopathological results to assess how accurately the histopathology was predicted by the MR imaging. The clinical features and outcomes of the two histopathological groups were also compared. RESULTS: The MR imaging findings were able to predict the histopathology accurately in the majority of cases. The group of patients with infarction had less severe clinical features and a better outcome than those with hemorrhagic infarction/hemorrhage. CONCLUSIONS: Magnetic resonance imaging findings in the setting of pituitary apoplexy accurately predict the nature of the apoplectic process and help to guide the type and timing of therapy.