Findings of magnetic resonance imaging of lumbosacral spine in chronic lower back pain Findings of magnetic resonance imaging of lumbosacral spine in chronic lower back pain

: *Background : Magnetic resonance imaging (MRI) of the lumbar spine is a safe and painless scan that uses a magnetic field and radio waves to produce detailed pictures of the lumbar spine (the bones, disks, and other structures in the lower back), MRI of the lumbar spine can be useful in evaluating symptoms such as lower back pain, leg pain, numbness, tingling or weakness or problems with bladder and bowel control. It can also help to diagnose tumors, bleeding, swelling, developmental or structural abnormalities and infections or inflammatory conditions in the vertebrae or surrounding tissues. Conclusion : 1.High incidence of abnormal MRI study in patients with chronic low back pain . 2.Highest percent of patients with chronic back pain had disc herniation follow by other pathology .


Findings of magnetic resonance imaging of lumbosacral spine in chronic lower back pain
‫الرنين‬ Findings of magnetic resonance imaging of lumbosacral spine in chronic lower back pain Abstract: *Background :Magnetic resonance imaging (MRI) of the lumbar spine is a safe and painless scan that uses a magnetic field and radio waves to produce detailed pictures of the lumbar spine (the bones, disks, and other structures in the lower back), MRI of the lumbar spine can be useful in evaluating symptoms such as lower back pain, leg pain, numbness, tingling or weakness or problems with bladder and bowel control. It can also help to diagnose tumors, bleeding, swelling, developmental or structural abnormalities and infections or inflammatory conditions in the vertebrae or surrounding tissues. Aim of study :To detect the cause of chronic lower back pain in patients referring from different departments in our hospital like Orthopaedics, Rheumatology , Surgery & neurology. *Patients & method : About 50 patients selected from February 2011 to December 2011 all of them are complaining from chronic lower back pain referring from different departments. Average age from 23 to 70 year, 31 were male &19 were female, the patients were classified according to their age, sex, occupation, past history of trauma, medical disease & previous surgery. *Results Twenty sex of patients (52%) were diagnosed as a PIVD (prolapsed intervertebral discs) at the level of L4-5 & L5-S1, ten(20%) of them diagnosed as degenerative disease of the discs, five patients (10%) diagnosed as Straitening of Spine ( Muscular Spasm), 2 (4%) of them diagnosed as secondary metastases in L1& 2 vertebral bodies, 3 (6%) of them diagnosed as infected disk with gibbus deformity in lower dorsal spines & 4 (8%) had normal lumbosacral spine .

Introduction:
Low back pain is one of the most common cause of physician visits in the world & frequently reported symptoms in the industrialized countries (1). In most cases the symptom is due to a benign non emergent condition involving some degree of spinal degeneration (2). Pain that continues for more than 7-12 weeks despite conservative management is described as chronic (3). The estimated prevalence of nonspecific chronic low back pain in adults is 15% but increases with increasing age to 44% at the age of 70 years (4,5). With conservative management if chronic low back pain does not improve, the cause must be identified before the most appropriate therapy can be determined. The sheer number of spinal structures that are potential sources of low back pain results in a broad differential diagnosis and represents a major challenge to identifying the cause of pain (6). A precise medical history and thorough physical examination, along with tailored laboratory testing and noninvasive imaging are important steps toward establishing a working diagnosis (7). These measures should suffice to identify or to rule out underlying disease processes (fracture, malignancy, visceral or metabolic abnormality, deformity, inflammation and infection) neurologic disorders requiring surgical intervention (cauda equina syndrome, myelopathy), and social or psychological distress that may amplify or prolong pain (8). However in most cases the initial clinical and imaging findings are nonspecific or insufficient for diagnosis (6). Chronic low back pain is described as nonspecific when the clinical and imaging findings have insufficient predictive values for the identification of symptomatic spinal structures (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). Among patients with chronic low back pain and without a demonstrated neurologic deficit or a disk herniation visible at imaging, a spinal cause was identifiable in only 15% (21). MRI of the lumbar spine considered by many to be the best imaging technique for the investigation of lower back pain displacing myelography and CT in recent years (22  As shown in table 3, in twenty sex patients the MRI finding was PIVD, the level of prolapsed was L4-5& L5-S1, Ten of them (38.6%) was posterolateral herniation more at left side, 11 of them (42.3%) was posterolateral prolapse more at right side, central posterior disk herniation found in 3 patients ( 11.5 % ) the remaining 2 patients (7.6%) had circumfrancial posterior disc bulge . As shown in table 4 the commonest site of prolapsed was at L4-L5 (53.8%) & at L5-S1 (42.4%), followed by other lumber levels. Table 4 The no. & percent of the patient correlate with the level of the prolapsed.

Discussion
: Back pain is pain felt in the back that usually originate from the structures in the spine, chronic backache is define as pain that lasting longer than three to six month . (24) There are several potential sources and causes of back pain, however the diagnosis of specific tissues of the spine as the cause of pain presents problems. This is because symptoms arising from different spinal tissues can feel very similar and is difficult to differentiate . (25) A systamatic review of the available literatures involving spinal MRI found MRI to be highly sensitive(89%-100%) imaging

Level of prolapse Patient
No.% L1-L2 0(0%) L2-L3 1(3.8%) L3-L4 0(0%) L4-L5 14(53.8%) L5-S1 11(42.4%) Total 26(100%) modalities for lumber spinal conditions & the quality of these images allows the diagnosis to make more details & accurate. (26) Many studies suggested that two conditions to which chronic backache is often attributed lumber disk herniation & degenerate end plates changes , degeneration of the intervertebral discs is common among patients with chronic back pain ( 27), our study inconsistence with those studies, in 52% the causes of chronic backache was disc prolapsed follow by 20% was degenerative changes at the end plates, also our findings go with De Palma et al (28) they confirm the disc prolapse (42%) as the most common etiology of chronic low back pain & go with findings of Jeroen et al , they confirm that more than half of patients with lower back pain undergo disc prolapse. (29 ) The commonest levels of prolapsed were L4-L5and L5-S1 which is go with Nada R. (30)who mention that the prevalence of bulge & protrusion was highest at L4-L5& L5-S1 also this finding go with Moore et al who found that majority of spinal herniation occur in lumber region (95%) in L4-L5or L5-S1 (31), this findings can be explain by the fact that nearly 75% of the lumbar flexionextension and of total spinal movement occurs at the lumbosacral junction, 20% of lumbar flexion-extension occurs at the L4/5 level and the remaining 5% is at the upper lumbar levels. Consequently, it is not surprising that 90% of lumbar disc prolepses occur at the lower two lumbar levels; the most frequently affected disc is at the L5/S1 & L4-L5 levels. (32) We found that common site of disk prolapsed was at posterolateral (Rt. posterolatral 42.3%, Lt. posterolateral 38.6%), which is inconsistence with Gerald et al (33)who found that disk tear are almost always postrerolateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal also go with Moore etal (31) who mention that herniations usually occur posterolaterally, where the annulus fibrosis is relatively thin and is not reinforced by the posterior or anterior longitudinal ligament (32).
Vertebral end plates play a key role in providing the nutrients to the intervertebral disk. As a result, it conceivable that changes in the end plates occur at the same time or even before disk degeneration(modic 34), in our study the MRI finding was degenerative changes modic type 1 at the vertebral end plates in 10(20%) patients our finding goes with the Kuisma et al (35) who reported significant association between Modic 1 changes and the frequency & intensity of lower backache but it not go with Mitra et al (36)who were not able to detect any statistically significant association between modic type 1 degenerative changes & patients symptoms. In five patients (10%) the MRI finding was straitening of spine with loss of normal lordoses most of them where male range of age 20-30 years old had previous history of lifting heavy weight, also there is many research support the possibility that low back pain can trigger spasm of paraspinal muscles such spasm thought to act as protective mechanism to spine injury(37,38&39) As MRI is the best approach for evaluation of spine metastases because its high soft tissue contrast results in excellent sensitivity, the sensitivity of MRI varies from 83%-100% and the estimated specify is 92%(40) , in 4 (8%)patients the MRI finding were 2ndary deposits in vertebral bodies due to primary tumor in male was malignant renal tumor metastases & in female was breast carcinoma . MRI is the method of choice for evaluation of spinal infection with sensitivity of 96% & specificity of 92%(41). In our study 3 (6%) patients the MRI findings were spondylitis representing as loss of normal signal intensity of vertebrae &discs with significant enhancement after contrast all of them were male & two of them had history of pulmonary T.B In this study we found high incidence of spine pathology(92%) in patients with chronic backaches & in four patients (8%) the MRI finding was quite normal inspited of back pain , this findings is in agreement with Bao-Gau who confirm that despite of inheret challenge in elucidating the specific etiology of chronic back pain diagnostic procedure can reveal its sources in 90% patients (42) *Conclusion: 1.High incidence of abnormal MRI study in patients with chronic low back pain . 2.Highest percent of patients with chronic back pain had disc herniation follow by other pathology .
Recommendation : Because of high incidence of abnormal spine in patient with chronic back pain & because of different pain causes, MRI is indicated to know the cause & to plane management . Beside disk prolapsed as cause of chronic backache other causes like infection & secondaries in spine should be excluded . Further study is suggested to follow up these patient by MRI after surgical or medical treatment correlate this findings with the patient pain.