Percutaneous discectomy on lumbar radiculopathy related to disk herniation: Why under CT guidance? An open study of 100 consecutive patients

The primary objective of this study conducted on 100 patients is to demonstrate that performing CT-guided percutaneous discectomy for herniated disks results in a significant improvement in pain symptoms at several times (D1, D2, D7, 1 month, 3 months, 6 months). This objective assesses the effectiveness and feasibility of this technique under CT guidance in patients presenting documented lower back pain related to disk herniation that has not improved with appropriate medical treatment. The impact of various factors on the effectiveness of discectomy will also be evaluated. At 1 week, we notes a decrease in average VAS respectively of 71% and 67% in patients treated for posterolateral and foraminal herniated disks; the result for posteromedian herniated disks is only 45% in average decrease. At 6 months post op, 79% of lateralized herniated disks have a satisfactory result (≥ 70% decrease in pain as compared to initial pain), whereas post median herniated disks had a satisfactory result in only 50% of cases. Percutaneous fine needle discectomy probe under combined CT and fluoroscopic guidance is a minimally invasive spine surgery which should be considered as an alternative to surgery. This technique presents several advantages: the small diameter of the probe used (maximum 16 G or 1.5mm) allows a cutaneous incision of only a few millimeters, and a trans-canal approach can be possible; it also decreases the risk of ligamentary lesion and does not cause an osseous lesion of the posterior arc or of the adjacent muscular structures.     

Preoperative Evaluation of Cervical Radiculopathy and Myelopathy by Surface-Coil MR Imaging

During a 2-year period, 256 patients were screened for cervical radiculopathy and myelopathy with surface-coil MR images and plain films. Selected patients had follow-up examinations including CT, myelography, and CT myelography. Thirty-four of these patients underwent cervical spine surgery after MR imaging, which disclosed a total of 50 abnormalities in three major categories: herniated disks, bony canal stenoses, and intradural lesions. MR correctly predicted 88% of all surgically proved lesions compared with 81% for CT myelography, 58% for myelography, and 50% for CT. Missed herniated disks on either MR or CT myelography usually were the result of technically suboptimal studies caused by motion artifacts on MR and beam-hardening artifacts on CT myelography. Small osteophytes adjoining herniated disks sometimes were not predicted on MR, although such osteophytes invariably were seen on plain films and were palpable during standard anterior cervical diskectomy procedures. Herniated disks in the lateral root canals found in two patients appeared to be detected more readily by CT myelography than by MR. All proved lesions were detected by either screening MR images and plain films or by follow-up CT myelograms. MR replaced invasive evaluations by myelography and CT myelography in 32% of preoperative patients.We conclude that MR images, combined with plain films, offer an accurate, noninvasive test for the preoperative evaluation of cervical radiculopathy and myelopathy, while CT myelography is the preferred follow-up examination.     

Preoperative evaluation of cervical radiculopathy and myelopathy by surface-coil MR imaging

During a 2-year period, 256 patients were screened for cervical radiculopathy and myelopathy with surface-coil MR images and plain films. Selected patients had follow-up examinations including CT, myelography, and CT myelography. Thirty-four of these patients underwent cervical spine surgery after MR imaging, which disclosed a total of 50 abnormalities in three major categories: herniated disks, bony canal stenoses, and intradural lesions. MR correctly predicted 88% of all surgically proved lesions compared with 81% for CT myelography, 58% for myelography, and 50% for CT. Missed herniated disks on either MR or CT myelography usually were the result of technically suboptimal studies caused by motion artifacts on MR and beam-hardening artifacts on CT myelography. Small osteophytes adjoining herniated disks sometimes were not predicted on MR, although such osteophytes invariably were seen on plain films and were palpable during standard anterior cervical diskectomy procedures. Herniated disks in the lateral root canals found in two patients appeared to be detected more readily by CT myelography than by MR. All proved lesions were detected by either screening MR images and plain films or by follow-up CT myelograms. MR replaced invasive evaluations by myelography and CT myelography in 32% of preoperative patients. We conclude that MR images, combined with plain films, offer an accurate, noninvasive test for the preoperative evaluation of cervical radiculopathy and myelopathy, while CT myelography is the preferred follow-up examination.     

The nuclear trial sign in thoracic herniated disks.

PURPOSE AND METHODS: Postmyelography CT studies of 84 patients with 114 thoracic herniated disks were reviewed for endplate irregularity, sclerosis, and/or disk-space calcification that could suggest a migratory path of the herniated fragment. RESULTS: Abnormal straight or curvilinear densities (the "nuclear trial sign") were present at the level of the disk or endplate in 46% of the cases. MR studies of 35 thoracic herniated disks were also examined. Similar changes were likewise present in 44%. CONCLUSION: The frequent occurrence of this finding in the mid and lower thoracic spine renders it a useful secondary sign for thoracic herniated disks, although false positives do occur.     

High-dose i.v. contrast in CT scanning of the postoperative lumbar spine

Evaluation of the postoperative lumbar spine is sometimes difficult because of obliteration of epidural fat by hypertrophic scarring. We examined 70 patients using a high-dose intravenous contrast technique in an attempt to distinguish hypertrophic scarring from herniated disk. The CT interpretation was confirmed in all 17 patients who had follow-up operations. Thirteen had herniated disk material associated with scar and four had hypertrophic scarring only. The latter four patients underwent reoperation because of concomitant foraminal or spinal canal stenosis seen on CT. Twelve of the herniated disks had the expected appearance of a nonenhancing mass surrounded by a rim of enhancing scar tissue. In the 13th patient, homogeneous enhancement of the herniated disk was seen. It is thought that chronically herniated disks, such as this one, may incite enough surrounding scar to give the CT appearance of an enhancing disk. Finally, marginal enhancement in the anulus fibrosus region was seen in over 90% of disk spaces examined. Although an anatomical explanation cannot be given at present, this phenomenon is thought to represent a normal finding.     

Late contrast enhancement in the CT diagnosis of herniated lumbar disk

Summary Twenty-five patients clinically suspected of herniated lumbar disk have undergone a CT examination before and 40 min after contrast enhancement. In every case, 13 of which were surgically verified, significant contrast enhancement of herniated disks was seen; there was only one false positive case. The authors conclude that late contrast enhancement really improves the CT diagnosis of herniated lumbar disk, particularly in cases with a doubtful or negative precontrast scan. The mechanism of the late contrast enhancement is discussed.     

Asymptomatic calcified herniated thoracic disks: CT recognition

Among 270 CT scans of the thorax obtained over a 7-month period, four patients (1.5%) with calcified herniated thoracic disks were identified. Each of these patients presented with abnormal chest radiographs and had a CT examination for evaluation of suspected malignancy. None showed any signs or symptoms of thoracic spinal cord compression. The clinical significance of incidental thoracic disk protrusions is unknown. It may be that these patients are at risk for the later development of symptomatic disk disease.     

Magnetic resonance imaging of the lumbar spine with CT correlation

The results of magnetic resonance (MR) imaging and computed tomography (CT) in 18 patients with known degenerative disk disease of the lumbar spine were compared. In 60 intervertebral disk levels studied, there were 17 disks with degeneration and disk bulge, and 15 herniated disks. Final diagnoses were based on several factors, with surgical confirmation in five patients. There was good correlation between the two methods at 51 of the 60 levels studied. However, there were major discrepancies in interpretation at nine intervertebral disk levels. These included three false-positive MR imaging interpretations of a herniated disk and one false-negative herniated disk on MR imaging. MR imaging detected one case of disk herniation that was missed prospectively on CT. There were also four presumed degenerated disks seen on MR scans that appeared normal on CT. The conus medullaris was imaged in 16 of 18 patients. The sagittal view proved best for demonstrating both disk abnormality and the conus medullaris. The transaxial view was sometimes helpful in localizing a disk herniation, but partial-volume averaging in the 7-mm slice thickness limited its usefulness. There were five disk herniations that could not be accurately localized on the MR scan. MR imaging proved more sensitive than CT in detecting early disk disease, which appeared as decreased signal intensity within the disk. In three postoperative cases, MR imaging was better able to distinguish between recurrent disk herniation and postoperative scar formation. CT, on the other hand, was more specific in distinguishing herniated disk from disk bulge and proved far superior to MR imaging in localizing disk herniation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Computed tomography in sciatica

Lumber facet arthropathy and a herniated disk are two major causes of low back pain and sciatica. The authors evaluated the importance of computed tomography (CT) in 243 patients with low back pain and/or sciatica. Lumbar facet abnormalities were found in 139 patients (57%), and a herniated disk was found in 48 patients (20%). CT findings correlated precisely with surgical observations in cases involving a herniated disk and correlated well with the results of an intra-articular facet block in a small series of patients. CT can effectively diagnose and differentiate between lumbar facet arthropathy and a herniated disk.     

CT或C臂导引下双点经皮激光椎间盘减压术治疗椎间盘突出症

目的：评价CT或C臂导引下采用双点（突出椎间盘中后部及患侧1/3处）经皮激光椎间盘减压术（PLDD）治疗椎间盘突出症的临床疗效、优越性及安全性。方法：160例椎间盘突出症患者中颈椎间盘突出12例,腰椎间盘突出148例,单间盘突出者150例,双间盘突（和/或膨）出者10例,所有病例均行双点PLDD术治疗。结果：穿刺成功率97.5%,无严重并发症发生,疗效评价优良率为91.1%。3个月后随访31.9%（51/160）患者突出物不同程度缩小、回纳。结论：双点法能进一步加强PLDD的疗效、操作简便、创伤小、恢复快且CT导引更准确、安全。     

Value of high-resolution computed tomography in evaluating cervical herniated disks

Previous difficulties in the diagnosis of cervical disk hernia were related to lack of non-invasive imaging techniques, but the gap has now been filled by CT scan imaging. A total of 442 patients with pains in neck, shoulder or arm were referred for a CT scan to exclude a cervical disk hernia. Of the group studied, 2% were found to have a herniated disk, 16% a lateral hernia and 9% combined lateral hernia-narrow cervical canal due to concomitant arthrotic changes. Assessment of correlation between CT scan images and myelographic and surgical findings indicated that CT scan imaging is a very precise, non-invasive method for investigation of cervical disk hernia.     

Periganglionic foraminal steroid injections performed under CT control.

PURPOSEThe purpose of our study was to evaluate the efficacy of direct intraforaminal steroid injections into the periganglionic space in the treatment of radicular pain.METHODSPeriganglionic infiltrations were performed in 41 patients with acute or chronic radicular pain. Neuroradiologic imaging in all patients showed foraminal stenosis due to degenerative disorders or herniated disk. All injections were performed under CT control.RESULTSSeventy percent of patients had significant pain reduction, with the greatest success (90% of patients) in those whose foraminal stenosis was due to degenerative disorders; 45% of patients with foraminal herniated disks had pain relief.CONCLUSIONIntraforaminal steroid injection is useful in the treatment of radicular pain, particularly in cases of foraminal degenerative stenosis.     

Computed tomography and myelography of the postoperative lumbar spine

Postoperative myelographic changes in the thecal sac, epidural tissues, and bony canal, as well as nerve roots, may be difficult to interpret. A series of 32 postoperative patients, all of whom had a metrizamide myelogram and subsequent lumbar computed tomogram, was reviewed to examine the ability of computed tomography to recognize abnormalities when the myelogram is equivocal or uninterpretable. Criteria to distinguish recurrent herniated disk from postoperative changes are presented, including the demonstration of mass densities similar to and in continuity with the intervertebral disk. In 12 reoperated cases, five recurrent herniated disks and two new herniated disks were diagnosed and confirmed. In 20 nonreoperated cases, no recurrent herniated disks were identified, although two new herniated disks were found at levels not believed clinically significant. Computed tomography after metrizamide myelography appears to be a reliable technique for distinguishing abnormalities in the postoperative spine.     

Multidetector CT in patients suspected of having lumbar disk herniation: comparison of standard-dose and simulated low-dose techniques

PURPOSE: To compare standard-dose and simulated low-dose multidetector computed tomography (CT) in patients suspected of having lumbar disk herniation. MATERIALS AND METHODS: The institutional review board approved the research protocol with a waiver of patient informed consent. Sixty consecutive patients underwent multidetector CT with four detector rows at 1 mm collimation at 140 kVp, with tube current-time product adapted to body mass index (BMI): 200 (BMI< 22 kg/m(2)), 300 (BMI > or =22 to <30 kg/m(2)), and 400 effective mAs (BMI > or =30 kg/m(2)). Simulated doses at 65%, 50%, 35%, and 20% of the dose were used for acquisition. During two separate sessions, three independent radiologists coded each of three caudal disks as normal, bulging, or herniated and graded canal and foramen compromise. Median numbers of discrepancies between the standard and reduced doses were compared with Friedman and Wilcoxon tests. Agreements within and between readers were evaluated through kappa statistics. RESULTS: Dose reduction had no effect on a reader's ability to identify bulging disks (P = .128) and left and right foramen compromises (P = .413 and .665, respectively). However, for normal disks (P = .002), herniated disks (P = .004), and canal compromise (P = .002), dose reduction did have a significant effect. For normal disks and canal compromise, a reduction dose effect was not detected at 65% (P = .121 and .250, respectively) but appeared at 50% (P = .004 and .008, respectively). For herniation, a dose reduction effect was detected at 35% (P = .031). Agreements within and between readers ranged from poor to excellent and tended to decrease with dose reduction. CONCLUSION: For patients suspected of having lumbar disk herniation, tube charge settings could be reduced to 65% of the standard dose adapted to the BMI.     

Percutaneous laser disk decompression under CT and fluoroscopic guidance: indications, technique, and clinical experience.

The aim of percutaneous laser disk decompression (PLDD) is to vaporize a small portion of the nucleus pulposus of an intervertebral disk, thereby reducing the volume and pressure of a diseased disk. This minimally invasive technique can be performed in patients who need surgical intervention for disk herniation with leg pain. PLDD is usually performed under fluoroscopic guidance with or without diskoscopy. However, it can also be performed under dual computed tomographic (CT) and fluoroscopic guidance as an outpatient procedure. CT and fluoroscopic guidance increases the safety and accuracy of PLDD, with high precision of instrument guidance, direct visualization of nucleus pulposus vaporization, and reduced risk of complications. Of 119 patients with lumbar disk herniation treated with PLDD under CT and fluoroscopic guidance, 91 (76.5%) had a good or fair response. PLDD performed with CT and fluoroscopic guidance appears to be a safe and effective treatment for herniated intervertebral disks.     

Lumbar herniated disk disease and canal stenosis: prospective evaluation by surface coil MR, CT, and myelography

Sixty patients with suspected lumbar herniated disk and/or canal stenosis were studied prospectively with surface coil MRI, CT, and/or myelography, and the results were compared with the surgically confirmed abnormality. Forty-eight patients had lumbar surgery at 62 levels. There were no negative explorations. Thirty-nine patients had a myelogram and CT. Thirty of the CTs were performed following the injection of metrizamide for myelography. Nine patients had a CT without intrathecal contrast material 1 to several days before the myelogram. Six patients had myelography only, and three patients had CT only. All studies were evaluated for the location and type of disease in a forced choice fashion. Independent of the surgically correlated levels, there was 86.8% agreement between the MR and CT studies in all patients at 151 levels and 87.2% agreement between MR and myelography at 218 levels. At the operative levels, there was 82.6% agreement between MR and surgical findings for both type and location of disease; 83% agreement between CT and surgical findings; and 71.8% agreement between myelography and surgical findings. There was 92.5% agreement when MR and CT were used jointly, and 89.4% agreement when CT and myelography were used jointly. The results of this study indicate that a technically adequate MR examination was equivalent to CT and myelography in the diagnosis of lumbar canal stenosis and herniated disk disease. CT and MR can be complementary studies, and surface coil MR can be viewed as an alternative to myelography.     

Recognition of cervical soft disk herniation by contrast-enhanced CT

A large number of patients with suspected cervical disk herniation were examined by high-resolution computed tomography (CT) with intravenous contrast enhancement. Thirteen herniated disks have been diagnosed by this technique. The disk protrusion causes displacement and a resultant filling defect in the epidural plexus, which is visualized after contrast enhancement. In some cases not clearly diagnosable by this method or by conventional myelography, the combination of intrathecal metrizamide and CT was most valuable.     

Can MRI signal characteristics of lumbar disk herniations predict disk regression?

PURPOSE: To assess whether or not MRI signal characteristics of lumbar disk herniations can predict subsequent disk regression. MATERIALS AND METHODS: Medical and radiology records from 1999-2003 were reviewed, and 123 patients who had more than one lumbar MRI during the study interval were identified. Of these, 42 patients had a disk herniation (protrusion, extrusion, or free fragment) identified on their first examination. Six of the 42 patients were not included because of prior lumbar surgery, or inadequate examinations. The remaining 36 patients had a total of 77 examinations to evaluate 44 disk herniations. The herniated disks were evaluated by two CAQ neuroradiologists for size, morphology and a qualitative assessment of the T2 signal. RESULTS: Between the first and last examination, 25 of 44 (57%) herniated disks decreased, 17 (39%) were unchanged, and two increased in size. 9 of 11 (82%) of disk extrusions improved. The mean size of the disks that regressed was significantly larger than those that were unchanged (8.6 mm vs. 6 mm, p=.001). On average, the disks decreased 3.2 mm (37%). Of the disks that decreased in size, 15 (63%) had an area of increased signal on T2-weighted images (T2WI) compared to the parent disk on the initial study. Of the disks that were unchanged, 6 (35%) had increased signal on the T2WI's. CONCLUSION: 57% of herniated disks in this study group decreased in size over time. Larger herniations and extrusions were more likely to regress than smaller herniations. Disks that regressed were more likely to have high signal on T2WI's than those that were stable.     

A sign of lumbar disk herniation recognizable on lateral CT generated digital radiograms

Computed tomography is a very sensitive and fairly specific imaging mode for diagnosing herniated disks in patients with low back pain and radiculopathy. We describe a new CT sign associated with posterior disk herniation that consists of a bony defect on the lower posterior angle of the proximal vertebral body and endplate shown on CT generated digital radiograms. This finding, by no means constant, is encountered frequently enough to be described as a sign of posterior disk protrusion. It often occurs concomitantly with posterior avulsion of a bone fragment probably related to avascular bone necrosis of the posterior inferior angle of the endplate.