Observation of herniated cervical intervertebral disc volume based on quantitative volume measurement “monitoring” based on PACS software / 中国组织工程研究

BACKGROUND: Herniated cervical intervertebral disc volume measurement is an important parameter for quantitative evaluation of cervical disc degeneration, but it faces a lot of problems such as different measurement standards and the undefined measurement error range. OBJECTIVE: To investigate the accuracy of PACS software in measuring cervical disc volume, provide reliable measurement methods and accurate data support for clinical observation and research on cervical disc volume change and degeneration. METHODS: The error rate was obtained by repeated measurements of the normal saline with a known volume of 5.0 mL by means of PACS software. With reference to this error rate, volume changes of cervical disc herniation before and after cervical microendoscopic laminoplasty were “monitored” and analyzed in 30 cases. This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (approval No. 2019-KY-274) on September 26, 2019. RESULTS AND CONCLUSION: (1) For the measurement of normal saline with known volume, it was found that the error rate of measurement by PACS software was ±5%, suggesting that the measurement of cervical disc volume by PACS software is a simple and accurate method. (2) After cervical microendoscopic laminoplasty, there were 70 patients with reduced cervical disc volume reduction absorption rate of 5%-100%, and the absorption ratio was 76.1% (70/92). The volume increased by 11, but the increase was not more than 5% in the patients with cervical disc herniation after treatment. (3) The spontaneous disappearance or reduction of the herniated cervical disc after cervical microendoscopic laminoplasty was as early as 7 days, and the longest was 76 months. (4) The effects were excellent in 11 cases, good in 15 cases, and fair in 4 cases. The excellent and good rate was 86.7%.

Delayed-Onset Leg Weakness Caused by Posterior Migration of a Herniated Disc to the Thecal Sac Mimicking Epidural Hematoma in a Flexion-Distraction Injury of the Lumbar Spine: A Case Report

STUDY DESIGN: Case report. OBJECTIVES: To document the first known case of posterior migration of a herniated disc in a lumbar flexion-distraction injury. SUMMARY OF LITERATURE REVIEW: Lumbar disc herniation is sometimes confused with epidural hematoma, especially when the disc migrates posterior to the thecal sac. There has been no report of posterior migration of a herniated disc after a lumbar flexion-distraction injury. MATERIALS AND METHODS: A 47-year-old woman with no pertinent medical history was diagnosed with a flexion-distraction injury of the L2–L3 vertebrae after a motor vehicle accident. The patient had no neurological deficit initially. Magnetic resonance imaging (MRI) showed a space-occupying lesion with T2 hyperintensity and T1 isointensity on the dorsal side of the thecal sac at L2–L3. After posterior lumbar fixation and fusion, progressive leg weakness occurred 1 week postoperatively. RESULTS: A second operation revealed no evidence of epidural hematoma, but a sequestrated disc. Decompression and sequestrectomy were performed, and the patient's neurological status had recovered fully at 4 months postoperatively. CONCLUSIONS: This case highlights the potential for posterior migration of a herniated disc with flexion-distraction injuries of the thoracolumbar spine. Discontinuity of the posterior annulus fibrosus on MRI may aid the distinction of posterior migration of a herniated disc from epidural hematoma. Because posterior migration of a herniated disc is associated with progressive neurological deficits, surgeons must consider decompression surgery when such herniation is suspected, even in the absence of neurological symptoms.

Variations in Matrix Metalloproteinase Expression by Disc Location in Patients with Sequestrated Lumbar Disc Herniation

STUDY DESIGN: In vivo study OBJECTIVES: To evaluate variations in matrix metalloproteinase (MMP) expression levels according to the disc location in patients with sequestrated lumbar disc herniation. SUMMARY OF LITERATURE REVIEW: MMPs are considered to be the major catabolic enzymes in the intervertebral disc. MMPs have been known to be the primary mediators of extracellular matrix (ECM) degradation, to play major roles in disc degeneration by changing the collagens and the extracellular matrix, and to be involved in the processes of apoptosis and autoresorption of herniated disc materials by inducing inflammatory cytokines. MATERIALS AND METHODS: The sequestered and contained disc materials were removed from seven patients with sequestered lumbar disc herniations. The materials from the contained discs were classified into group 1 and those of the sequestered discs into group 2. Immunochemistry tests were conducted for the tissues of both groups. The expression levels of MMP-1, 3, and 13 were checked using a fluorescence microscope. The amount of expression of each MMP was calculated using the percentage of expressed cells and analyzed statistically. RESULTS: In the histological study, increased expression of MMP-1, 3, and 13 was found in group 2. In the statistical analysis after the quantification of MMP expression, the expression of all MMPs was found to have increased significantly in group 2 (p<0.05). CONCLUSIONS: The increased expression of MMP-1, 3, and 13 indicated that the inflammation and degeneration processes, and the spontaneous resorption by the surrounding tissues were more active in the sequestered disc group than in the contained disc group.

Expression of Growth Factors and Cytokines in Patients withDegenerated Disc Disease and Herniated Nucleus Pulposus

OBJECTIVE: To investigate the expression of cytokines and growth factors in disc specimens obtained from small numbers of patients with herniated nucleus pulposus (HNP) and degenerated disc disease (DDD). METHOD: A total of ten human intervertebral disc samples consisted of five painful degenerative discs and five herniated intervertebal discs were obtained from surgery. MRI and Western blot analyses on these disc samples were performed to determine the levels of disc degeneration and the expression levels of cytokines and growth factors. RESULTS: The levels of IL-6 were significantly greater in the DDD patients than in the HNP patients, but no statistical differences were observed in the expression of IL-1beta, IL-8 and TNF-alpha between the HNP and DDD patients. In addition, the expression of TGF beta was significantly higher in the DDD patients than in the HNP patients. CONCLUSION: The higher levels of cytokine and growth factor expression in the DDD than in the HNP show why discogenic patients usually have more severe back pain than patients with herniated discs.

Transforaminal Selective Nerve Root Blocks for Treating Single Lumbosacral Radiculopathy: The Short-term Outcome and Efficiency / 대한정형외과학회잡지

PURPOSE: We wanted to determine the clinic usefulness of selective nerve root block for treating lumbosacral radiculopathy that's due to a herniated nucleus pulposus (HNP) or foraminal stenosis (FS) by analyzing the short-term results after the selective nerve root block (SNRB) procedure. MATERIALS AND METHODS: Sixty-five patients were investigated in our research. Sixty-five patients were divided into two groups: thirty-seven patients of group one were the HNP patients and twenty-eight patients of group two were the FS patients. The effect of SNRB treatment was assessed by the degree of radiating pain in lower legs with using the visual analogue scale (VAS) and patients' subjective satisfaction. The average overall follow-up period was eleven months: that of the first group was 13.5 months and that of the group was 7.6 months. RESULTS: For the 65 patients, the average VAS was 7.8 before a SNRB procedure and this decreased to 2.9 and 3.4 after one to three SNRB procedures, respectively. For group one, the VAS was 7.4 before the procedure and it decreased to 3.3 at one month and 3.7 at three months after the procedure. For group two, the VAS was 8.3 before the SNRB procedure and this favorably changed to 2.3 at one month and 3.0 at three months after the procedure. An operation was carried out due to no response for 8 patients (12%) and due to aggravation for 4 patients (6%) after the SNRB procedures. Three patients (8%) of group one and two patients (11%) of group two obtained pain relief at one month and aggravation at three months, respectively. On comparing the two groups, a better treatment effect was observed for the FS group after one month (p=0.002) and three months (p=0.01). Complications related to the SNRB procedure haaves not been observed in both groups. CONCLUSION: The SNRB procedure is a very effective and safe procedure, after the appearance of symptoms, as a non-operative treatment for single lumbosacral radiculopathy due to a herniated nucleus pulposus or foraminal stenosis. This treatment appears to be more effective for the FS group than for the HNP group and it should be considered before carrying out an operative treatment.

The Effective Steroid Dose of Caudal Epidural Injection with Unilateral Epidural Catheter Position in Patients with Symptomatic Herniated Nucleus Purposus / 대한마취과학회지

BACKGROUND: The epidural steroid injection is commonly used in the management of chronic low back pain and radiating pain. We compared the efficacy of 40, 60, and 80 mg of methylprednisolone acetate in patients with lumbar herniated disc disease treated with caudal epidural block. METHODS: Seventy-two patients with lumbar herniated nucleus purposes on magnetic resonance imaging were included.All patients received fluoroscopically guided caudal epidural injections, with the guidewire-reinforced epidural catheter introduced through a Tuohy needle.After confirming the catheter tip position at the affected nerve root, contrasts were injected until patients felt discomfort in their site of pain.24 patients in each group received 40 mg, 60 mg, 80 mg of methylprednisolone acetate, respectively.We evaluated the improvements by pain relief scale (0-100%) after 2 weeks. RESULTS: There are no significant differences in the pain improvement between three groups (P = 0.537 ). CONCLUSIONS: Sixty and 80 mg methylprednisolone acetate injection during caudal epidural block showed no further benefit compared to 40 mg injection.

Lumbar Discectomy Using Tubular Retractor and Microendoscopy / 대한척추외과학회지

STUDY DESIGN: Retrospective study OBJECTIVES: To compare the surgical results of microendoscopic discectomy using a tubular retractor with those of a conventional discectomy for lumbar herniated nucleus pulposus. SUMMARY OF LITERATURE REVIEW: Minimally invasive approaches to the lumbar spine have been attempted with success over the past 25 years. MATERIALS AND METHODS: This study examined 36 cases who underwent lumbar discectomy using a tubular retractor and microendoscopy (Group A) and 30 cases who underwent a conventional discectomy (Group B). The operating time, intraoperative blood loss, postoperative hospital stay were recorded. The clinical results were assessed using the Korea Version Oswestry Disability Index (KODI), and the radiological results were evaluated from changes in disc height. RESULTS: The patients in Group A had a longer operation time(mean, 95.56+/-23.57 minutes vs 81.17+/-35.30 minutes, p=0.062), less intraoperative blood loss (mean, 58.61+/-97.08 cc vs 161.00+/-88.64 cc, p=0.001) and a shorter hospitalization stay (mean, 8.22 +/-4.99 days vs 17.33+/-10.98 days, p=0.001) than group B. There was significant improvement in the mean KODI score for Group A; 6.36+/-7.18 and Group B; 5.97+/-5.14. However, there was no significant difference in the pain improvement (mean, 1.14 +/-1.15 vs 1.30+/-1.06, p=0.559) and walking index (mean, 0.25+/-0.44 vs 0.30+/-0.47, p=0.656). In terms of social life, Group A had better results (mean, 0.20+/-0.48 vs 0.67+/-1.01, p=0.018). The disc height according to radiography decreased from 8.44+/-1.98 mm to 7.40+/-1.59 mm in Group A and 9.07+/-1.93 mm to 7.67+/-1.90 mm in Group B, but there were no statistical differences in the changes in disc height between the two groups (p=0.143). CONCLUSION: Microendoscopic discectomy is an effective procedure with good outcomes in treating lumbar disc herniation that allows less tissue trauma, compared with conventional open discectomy.

Nerve Ingrowth into Intervertebral Disc in Internal Disc Disruption / 대한척추외과학회지

STUDY DESIGN: The ingrowth of the nociceptive nerve ending into intervertebral disc was examined using immunohistochemistry and quantified using western blotting. OBJECTIVES: To determine if the nociceptive nerve innervates into the intervertebral discs of internal disc disruption (IDD). SUMMARY AND LITERATURE REVIEW: Nociceptive nerve ending and vessel ingrowth into intervertebral disc is associated with IDD and HNP. Substance P is a neurotransmitter that is found in the nociceptive nerve endings. Immunohistochemistry has confirmed the presence, and western blot has isolated the target. The localization of novel nociceptive innervation, and a quantitative comparison was made according to the original pathology is of interest. MATERIALS AND METHODS: 10 specimens of intervertebral disc were collected from IDD during total disc replacement surgery , and another 10 specimens of intervertebral disc from HNP were collected during discectomy. The control samples of intervertebral disc were obtained from 3 adolescent patients with idiopathic scoliosis, and 2 patients with a lumbar bursting fracture. Standard immunohistochemical techniques were used to test for the nociceptive neurotransmitter (substance P), which is a protein expressed during axonogenesis (growth-associated protein 43, GAP43), and a general nerve marker (protein gene produce 9.5, PGP9.5). The expression of substance P protein was quantified using western blot for its polyclonal antibody. RESULTS: In IDD (n=10), substance P was expressed in 6 cases of outer annulus fibrosus (AF), 5 cases of inner AF, and 3 cases of nucleus pulposus (NP). In HNP (n=10), substance P was expressed in 4 cases of outer AF, 3 cases of inner AF, and 2 cases of NP. In the control group, only 2 cases expressed substance P in outer AF. GAP43 was only positive in outer AF as follows: IDD 3 cases, HNP 1 case, and control 1 case. None of the specimens showed localized PGP 9.5. Substance P was localized significantly in larger quantities in IDD than in the control group (p=0.002). In HNP, the expression level was larger than the control and lower than the IDD group but this was not statistically significant (p=0.158, p=0.108). CONCLUSIONS: Innervation of nociceptive nerve endings was identified at the degenerative intervertebral disc of IDD, which may contribute to back pain.

Caudal Epidural Injection with a Guidewire-Reinforced Epidural Catheter in Patients with Herniated Nucleosus Pulpose / 대한통증학회지

BACKGROUND: The epidural injection technique is a commonly used intervention in the management of chronic spinal pain, which has the advantage of delivering various drugs, such as local anesthetics or steroids, in higher concentrations to the inflamed nerve root. A guidewire-reinforced epidural catheter was introduced through a Tuohy needle during the caudal epidural procedure, with a catheter threaded into the affected nerve roots and the spread-pattern of contrast agents observed under fluoroscopy. METHODS: Sixty-seven patients with low back pain, who showed evidence of a herniated nucleus pulposus on magnetic resonance imaging, were included. All patients received fluoroscopically guided caudal epidural injections, with the guidewire-reinforced epidural catheter introduced through a Tuohy needle and threaded either to the right or left side toward the target nerve roots. After confirming the catheter tip position at the affected nerve root, 2 ml increments of contrast agents (up to 6 ml) were injected, and their corresponding AP fluoroscopic views were obtained. Three radiologists reviewed all the radiographic findings and measured the proportion of the area of contrast spread at the side of target nerve roots. RESULTS: Greater proportion of the area of contrast spread was observed at the side of the target nerve roots (P < 0.0001). At each level of contrast injection (2- , 4- and 6 ml), more than 70% of the spread of contrast dye was observed at the side of the target nerve roots in 85%, 70%, and 55% of cases, respectively. CONCLUSIONS: The combination of a caudal epidural injection and use of a guidewire-reinforced epidural catheter significantly enhances the target specificity, as revealed by the selective spread of contrast dye at the side of target nerves.

Herniated Nucleus Pulposus during Pregnancy / 대한주산의학회잡지

A herniated nucleus pulposus (HNP) during pregnancy has been a rare occurrence with a reported incidence of 1:10,000 case. It is hard to diagnose because of the potentially hazardous effect of ionizing radiation to the fetus when complaining back pain during pregnancy. In this case, magnetic resonance imaging (MRI) provide safe and useful modality and in general, back pain usually respond readily to conservative treatment. Cauda equina syndrome or severe and/or progressive neurologic deficit is a medical emergency that necessitates prompt surgery during pregnancy. She admitted at 31 weeks gestation for sudden development of right leg paresthesia and ankle motor weakness, an MRI showing compression on right nerve root at the level of L5~S1. After 4 weeks treated with bed rest and analgesics, we delivered by cesarean section and laminectomy at the same time. We have experienced a pregnancy with HNP, so report of this case with brief review of literature.

Intraoperative Straight Leg Raising Test During Arthroscopic Microdiscectomy / 대한척추외과학회지

STUDY DESIGN: A prospective study. PURPOSE: To assess the effectiveness of the straight leg raising test during an arthroscopic microdiscectomy. MATERIALS AND METHODS: 52 patients, 38 men and 14 women, took part in this experiment. The mean followed up and age were 21, ranging from 13 to 41 months, and 26.4, ranging from 13 to 42 years old. There were 19, 28 and 9 cases between the 3rd- 4th lumbar vertebrae, between the 4-5th lumbar vertebrae between the 5th lumbar vertebra and the 1st sacral vertebra, respectively. 41 patients were able to perform the SLRT (straight leg raising test) procedure, and were called group I, and 11 patients could not perform the test, and were classed as group II. In order to perform the intraoperative SLRT, a lateral decubitus position was adopted. After the disc removal, the SLRT was carried out. When the test result gave an angle of 70 degrees or greater, the surgery was carried out on a pertinent domain. The success of the surgery was graded by the JOA score. RESULTS: In group I, after removal of the disc, the first 31 patients were checked over a 4 week period to assess their recoveries. A year after the surgery, their follow up results were better than Good. In 9 patients, there were little improvements from the first SLRT, so they were re-tested after a 2nd discectomy, which resulted in improvements., with better than good results. 1 patient, whose test result was fair after four weeks and one year, was diagnosed with spinal stenosis, so underwent an operation. In group II, the SLRT during surgery was untestable, due to overweight and uncooperative patients. The results in 3 patients were fair, and in another 8 they better than good. Overall, 97.6% of the patients in group I showed a rapid recovery, but in the group II, only 72.2% showed a rapid recovery. CONCLUSION: From the short term follow up, the use of a SLRT during surgery is very effective. Further research is required to give more precise results.

Assessment of Job Related Factors as Determinants of Incidence of Herniated Lumbar Disc / 대한산업의학회지

OBJECTIVES: A case-control study was conducted on 2,323 male soldiers(771 herniated nucleus pulposus patients and 1542 controls) to identify risk factors for cumulative trauma disorders especially lower back. METHODS: The collecting data included individual physical, psychological, and work environmental factors. Korea Military Personality Inventory(KMPI) was used to examine the assess trait that have been associated with clinically with herniated nucleus pulposus. A measurement of the workplace support system was obtained by using of the modified work APGAR, a brief, seven-item workplace function questionnaire. RESULTS: The herniated nucleus pulposus patients were more common among Artillerymen and Engineer than among infantrymen. In logistic regression analysis of military occupational specialties, Artillerymen, Engineer, radio operator, driver were higher risk of herniated nucleus pulposus than infantrymen. Multivariate analysis of KMPI scales found hypochondriasis scale, hysteria scale, hypomania scale, social introversion scale to have strong relationship to incidence of herniated nucleus pulposus. And 'can communicate with peers' and 'enjoy job task' item of modified work APGAR to have strong relationship to incidence of herniate nucleus pulposus CONCLUSIONS: Study of the relative contributions of many physical and non physical variable shows that evaluations of back problems in workplace that exclude these highly significant work perception and psychosocial variables are of limited value. Simple, unidimensional approaches that ignore the effect of work perceptions and psychological factors on back problems reporting oversimplify a multifaceted problem. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaint in workplace.

Anterior interbody fusion in the treatment of the lumbar herniated nucleus pulposus

One hundred and fourteen cases of lumbar herniated nucleus pulposus were studied retrospectively. I reviewed the clinical records and radiographs of patients treated with diskectomy and anterior interbody fusion. I followed the patients from 2 years up to 15 years, for an average of 2.9 years. The results were calculated statistically by Fisher exact test and Chi-square test. Among 114 patients, 69 patients (60.5%) were male and 45 patients (39.5%) were female. The most common age group was in its twenties (28.1%), while the whole study group ranged from 19 to 65 years. The most commonly involved level was L4-5 (73 cases, 60.4%). In clinical results, 83.3% of cases were excellent or good. The rate of solid fusion was 87.8%. The most common type of fusing pattern was type 1. The satisfying clinical result had statistical correlation with the solid union of grafted bone and the fusion state of maintained intervertebral disk height, respectively, by Fisher exact test (p < 0.001). The affecting factors in clinical results were the solid fusion and fusion with the state of maintenance of intervertebral disk height (fusing pattern type I and II). I concluded that anterior diskectomy and interbody fusion is a recommendable method of treatment for lumbar herniated nucleus pulposus.

Anterior Interbody Fusion for Lower Lumbar Spinal Diseases / 대한정형외과학회잡지

There are several modalities of surgical treatment in lumbar herniated nucleus pulposus (HNP), derangement of lumbar intervertebral disk (DLID), spondylolysis, spondylolisthesis and degenerative spinal stenosis with scoliosis, such as laminectomy, laminectomy and diskectomy, laminectomy with diskectomy and posterolateral fusion, laminectomy with diskectomy and posterior lumbar intebody fusion, anterior diskectomy and interbody fusion, modification with cage instrumentation and decompression with instrumentation and posterolateral fusion. Low back pain due to the instability resulting from the removal of the nucleus pulposus was not infrequent in clinical practice. The purpose of the study was to determine the factors affecting clinical results by evaluating fusion rate, fusing pattern, measurement of spinal canal, correction of deformity. Five hundred and twenty eight cases of lower lumbar spinal diseases including 2S6 cases of lumbar HNP and DLID, 189 cases of spondylolysis and spondylolisthesis and 53 cases of spinal stenosis with scoliosis were studied respectively. The cases were admitted to Severance Hospital department of Orthopaedic Srugery from January 1970 through December 1994, and followed the patients from two years up to 15 years with an average of 2.9 years. It was reviewed clinical records and radiographs. The radiological study included plain x-ray, dynamogram, tomogram, myelography, computed axial tomography and/or MRI. It was evaluated the fusion rate, fusing pattern, area of spinal canal, correction of deformity and clinical results. The rate of solid fusion was 89.5% in lumbar HNP and DLID, 77.3% in spondylolysis and spondy-lolisthesis, and 86.7% in spinal stenosis with scoliosis. The most common type of the fusing pattern was type I in lower lumbar diseases. The satisfying clinical result was 82.6% in lumbar HNP and DLID, 76.7% in spondylolysis and spondylolisthesis and 58.5% in spinal stenosis with scoliosis. Spinal canal measurement was done in 23 cases and the increase of A-P diameter of spinal canal was 0.50+/-0.29mm and it was correlated with satisfying clinical result. Correction of the deformity was evaluated in 53 cases of spinal stenosis with scoliosis and of them 67.9% was corrected and it was correlated with satisfying clinical result. In conclusion the factors affecting the satisfying clinical results in the lower lumbar spinal diseases treated by diskectomy and anterior interbody fusion are solid union, restoration of disk height, correction of the deformity and increment of area of dural sac. Anterior diskectomy and interbody fusion have shown to be a good method of treatment for lower lumbar spinal diseases.

A Spinal Cord Tumor Found in the Patient with Herniated Nucleus Pulposus / 대한마취과학회지

A 35 years old female patient was admitted to our neuro-pain clinic with symptoms of low back pain(L4, L5 level) radiated to both lower(L3, L4, L5 level) extremities that developed 6 years prior to admission. Upon initial physical examination, motor weakness or sensory deficit was absent. But on straight leg raising test, it was restricted to 60 degree in both lower extremities. Low back pain and radiating pain improved significantly after we performed epidural steroid injection. However on the next day of procedure the patient complaints more pain and started to experience severe pain during overnight for 3 days. On computer tomography(CT, L3-S1 level), we find suspicious lesion of herniated nucleus pulposus at L5-S1. Otherwise were within normal limits. Based on these symptoms, to find the other lesions, subsequently magnetic resonance imaging(MRI) was performed. Spinal tumor was seen at L2-3 level(2 2 4 cm). Neurosurgical surgery was recommended, and operation was performed. The patient was diagnosed to ependymoma after excision and cytologic studies. Even if one lesion was diagnosed, it must be put off until any other diseases or underlying cancer are ruled out. We report a patient with spinal cord tumor missed on CT, but revealed on MRI in the evaluation and management of herniated nucleus pulposus related(L5-S1) low back pain.

Ligamentoplasty in Lumbosacral Vertebrae using BOP

BOP is made of N-Vinyl pyrrolidone-Methylmethacrylate monomer, polyamide fibres, and calcium glusconate. BOP is biocompatible, biodegradable, and osteoconductive matrix, easy to use and quite safe. Authors have operated 14 patients who has bilateral hernaiated nucleus pulposus, multiple herniated nucleus pulposus, or herniated nucleus pulposus accompanied with spinal stenosis, spondylolysis or spondylolisthesis in lumbosacral portion from September, 1989 till August, 1990. The results were satisfactory. We analysed this patients and report the method of ligamentoplasty with the discussions about spinal fusion and spinal instability.

Measure-set computed tomography in the diagnosis of herniated nucleus pulposus

The present study has been carried out to enhance the specificity of computed tomography (CT) in diagnosing herniated nucleus pulposus (HNP) of the lumbar spine by the application of measure-set (MS) technic. MSCT scans of 20 patients with proven diagnosis of HNP were reviewed prospectively to sort out features of diagnostic value. Eleven were men and 9 were women with the mean age being 40 years. MSCT scan revealed dislocation of the center of the nucleus pulposus (NP) in direction of herniation in 75%, "permeation" of the annulus fibrosus (AF) by HNP material and a clear disruption of the outermost layer of AF in all patients. The site and grade of the protrusion of HNP beyond the normal saliancy of AF could be easily evaluated in 90%. The present study saliancy of AF could be easily evaluated in 90%. The present study revealed that MSCT can demonstrate four characteristic findings of HNP enabling one to directly and semiquantitatively assess the pathologic changes of NP.