Lying Supine In the supine position, the neurological examination can be completed with regard to the assessment of: muscle strength [dorsiflexion of the foot (L4) and greater toe (L5)] muscle strength for inversion (L5) and eversion (S1) of the foot long tract signs (Babinski, Gordon, Oppenheimer, Rossolimo, see Chapter 11 ) abdominal reflexes (see Chapter 11 ) presence of any spasticity of the lower extremities (see Chapter 11 ) Lhermitte sign Straight leg raising test Radicular pain provocation is the key aspect of the Las`egue sign The Lhermitte sign is provoked by forceful flexion of the head. The test is positive if the patient has a sensation of electrical shocks in the body and lower extremi- ties. This sign is indicative of a severe spinal cord compression. There is a pleth- ora of descriptions of the Las`egue sign (test). We regard the test as positive in the presence of radicular leg pain. It is important to precisely ask the patient what they are experiencing while the straight leg is raised. We always note the elevation degree when radicular pain is experienced. Any other sensation than radicular pain is not regarded as a true Las`egue sign and can be described as a pseudolas`e- gue sign. The latter sign does not exclude the presence of a radiculopathy but is often caused by a severe muscle spasm. Most frequently,thepatient is just experi- encing tension in the popliteal fossa as a result of tight hamstrings. A cross-over sign is present when the patient experiences radicular pain in the affected leg while raising the contralateral leg and is highly predictive of a large median disc herniation [18]. Do not overlook a hip joint disorder While the patient is in the supine position, the hips should be examined so as not to overlook a hip pathology, which is frequent in elderly patients. The diag- nosis of an affection of the sacroiliac join t is very difficult clinically because this jointisnoteasilyaccessible.Itispossibletocompressordistractthesacroiliac joint and provoke pain in the case of an affection. However, we can also use the femur as a lever to move the sacroiliac joint. The so-called Patrick test is per- formed by flexing the ipsilateral hip and knee and placing the external malleolus of the ankle over the patella of the opposite leg. The examiner gently pushes the ipsilateral knee down until a hard resistance is felt. At this point, the examiner gives a short impulse on the ipsilateral knee, i.e. pushing it towards the examina- tion table. The test is positive if the patient feels the usual buttock pain ( Fig. 5 ). The examination in the supine position is completed by assessing the arterial pulses with regard to an important differential diagnosis of neurogenic claudica- tion. LyingonLeft/RightSide Hip abduction differentiates L5 radiculopathy and peroneal nerve palsy The patient is asked to lie on their left and right side, respectively. In this posi- tion, the hip ab duction is tested with the lower knee flexed and the upper knee extended. Normal hip abduction force (L5) in the presence of a foot drop is indic- ative of a paresis of the peroneal nerve ( Case Introduction). In this position, a further test for sacroiliac joint affection can be done (Men- nell test). The upper hip is extended and the knee flexed. The examiner places one hand on the ipsilateral hip and with the other hand extends the hips gently until a hard stop is felt. At this point the examiner gives a short impulse by pulling the leg in more extension. The test is positive if the patient feels the usual buttock pain. 220 Section Patient Assessment In the lateral position, the perianal sensitivity and sphincter tone can be tested to rule out a cauda equina syndrome. Lying Prone The reversed Las`egue sign is tested with the leg extended In this position, the reversed Las`egue sign or femoral stretch test can assess lum- bar disc herniations at higher levels (L2–4). The test is positive if extension of the straight leg is causing anterior thigh pain. It is important to perform the test with the leg straight, because flexion of the knee stretches the quadriceps muscle, which makes it difficult to separate neural and muscular pain. Palpation is rarely diagnosticFinally, the spinous processes, paraspinal muscles and the posterior superior iliac spine can be palpated. Although this examination seldom provides a clue for the underlying pathology, it is psychologically important as outlined above. Abnormal Illness Behavior Positive Waddell signs suggest non-organic causes of symptoms If there is some doubt regarding the severity or genuineness of the patient’s com- plaints, not only the patient’s pain drawing [26] will show frank exaggeration or non-anatomic pain patterns [38], but several tests might also be useful in this set- ting. Waddell [36, 39] described five signs to help reveal functional overlay in back pain patients. presence of widespread superficial tenderness pain on axial loading or simulated rotation postural differences in straight leg raising test regional non-anatomic sensory/motor disturbances overreaction (crying out, facial expression, sweating, collapsing) Vertical compression on the head in the standing position is not translated to the lumbar spine. When the patient is standing and presses their arms firmly against the greater trochanters, the first 30 degrees of rotation occur in the hip joints. Both tests therefore should not cause low-back pain unless psychological overlay is present. Large differences (<20 degrees) of the straight leg raising test between sitting and lying cannot be explained pathoanatomically and are indicative of abnormal illness behavior. Reproducibility The reproducibility of history and physical findings is limited It is important to note that findings during history taking and physical assess- ment are hampered by a poor or only modest reproducibility. This has to be borne in mind when using this data for outcome evaluation and scientific pro- jects [4, 20, 24, 28, 32, 33, 40]. The reproducibility of history of having ever expe- rienced back pain has been reported to be around 80% [4, 40]. The same has been found for pain drawings made by patients [19]. Retrospective data obtained by means of subjective patient statements should be handled with great caution. With regard to physical signs, only a few studies have addressed the issue of reproducibility [4, 20, 22, 24, 29]. McCombe found that reliable signs consisted of measurements of lordosis and flexion range, determination of pain on flexion and lateral bend, nearly all measurements associated with the straight leg raising test, determination of pain location in the thigh and legs, and determination of sensory changes in the leg [20]. History and Physical Examination Chapter 8 221 Differential Diagnosis of Spinal Pain Syndromes The differential diagnosis of spinal disorders in general and low-back pain par- ticularly is far reaching. The differential diagnosis of spinal pain syndromes includes neoplasia, infection, inflammatory disease, as well as pelvic organ disor- ders, and renal and gastrointestinal disorders. Jarvik and Deyo differentiate non- mechanical spinal conditions and visceral disease ( Table 8)frommechanical low-back pain in the differential diagnosis of low-back pain [8, 17]. Table 8. Differential diagnosis of low-back pain Non-mechanical spinal conditions (1%) Visceral disease (2%) Neoplasia (0.7%) multiple myeloma metastatic carcinoma lymphoma and leukemia spinal cord tumors retroperitoneal tumors primary vertebral tumors Infection (0.01%) osteomyelitis septic discitis paraspinous abscess epidural abscess Inflammatory arthritis (0.3%) ankylosing spondylitis psoriatic spondylitis Reiter syndrome inflammatory bowel disease Paget disease Pelvic organ involvement prostatitis endometriosis chronic inflammatory disease chronic pelvic inflammatory disease Renal involvement nephrolithiasis pyelonephritis perinephric abscess Gastrointestinal involvement pancreatitis cholecystitis penetrating ulcer Aortic aneurysm Figures in parenthesis indicate estimated percentage of patients with these conditions among all adult patients with signs and symptoms of low-back pain according to Jarvik and Deyo [17] Recapitulation History. The high rate of benign self-limiting low- back and neck pain can disguise serious underlying causes of spinal pain. The most important task of the clinical assessment is to rule out serious illness indicated by the so-called red flags, i.e., features of caudaequinasyndrome,severeworseningpain (especially at night or when lying down), significant trauma, fever, unexplained weight loss, history of cancer, patient over 50 years of age, and use of in- travenous drugs or steroids. Tumors and infections must be ruled out. Furthermore, a relevant paresis (motion of the extremity against gravity impossi- ble) must be detected early and treated. After red flags are ruled out, the clinical assessment focuses on the three major complaints which lead patients to seek medical help, i.e. pain, functional impair- ment, and spinal deformity. The most important differentiation of pain is the distribution between central (back/neck) and peripheral pain (leg/arm). Radicular pain must be distinguished from axial (central) pain. Radicular pain is usually attributable to a pathomorphological correlate. Pain intensity should be assessed with a visual analogue scale. The assessment of positional and activity modula- tors of spinal pain is very helpful for further differ- ential diagnosis of the pain syndrome. Physical im- pairment should be differentiated from disability and handicap. The history of patients with spinal deformity should include the assessment of spinal deformities requiring some specific additional in- formation from the patient (or parents). The pa- tients should be explored with respect to: family history, course of pregnancy and delivery, develop- mental milestones (onset of walking, speaking, 222 Section Patient Assessment etc.), fine motor skills, tendency to fall (clumsiness), onset of menses, and evidence of metabolic or neu- romuscular disorders. Examination. The physical examination is per- formed with the patient in different positions, i.e. walking, standing, sitting, lying supine, lying on the left/right side, lying prone. During walking the presence of a limp, ataxia, and muscle force (walk- ing on hips/tiptoes) is assessed. The most impor- tant aspect for the examination in the standing position is the assessment of the sagittal and coro- nal balance. The sagittal profile (lordosis/kyphosis) is largely variable. Finger floor distance is an assess- ment of the hip flexion and muscle stretch. Repeti- tive testing of a motion (tiptoe standing, stepping up on a stool) may disclose a subtle muscle weak- ness. In the seated position, the examination for sensory deficits, muscle weaknesses and tendon reflexes is facilitated. Similarly, the examination of the cervical spine is best performed with the patient in this position. Rotation in flexion exam- ines the upper cervical spine and rotation in exten- sion of the lower cervical spine. In the seated posi- tion radicular provocation tests (Spurling’s test, Valsalva maneuver, and shoulder depression test) can be performed to provoke typical radicular pain. In the supine position, the straight leg raising test (Las`egue sign) is performed. The most important read-out of this test is the provocation of radicular pain, which is pathologically independent of the degree of hip flexion. Elicited non-radicular pain can be classified as a pseudolas`egue sign. The assessment of hip and sacroiliac joint function as well as vascular status should not be forgotten. In the left/right side position, assessment of the hip abduction force is important for a differential diag- nosis of L5 radiculopathy and peroneal nerve palsy. In this position, the perianal sensitivity and sphinc- ter tonus are best assessed. In the prone position, the reversed Las`egue sign (for nerve root compro- mise, L2–4) can be tested. The palpation of the dor- sal and lumbar spine is hardly ever diagnostic but should not be discarded for psychological reasons. The assessment of abnormal illness behavior is mandatory. In general, the reproducibility of history taking and physical examination is limited. The dif- ferential diagnosis of spinal pain syndromes includes cancer, infection, inflammatory disease, as well as pelvic organ disorders, and renal and gastro- intestinal disorders. Key Articles Biering-Sorensen F, Hilden J (1984) Reproducibility of the history of lo w-back trouble. Spine 9:280– 6 This paper reports on the reproducibility of auto-anamnestic information concerning low back trouble. The authors found that within a year, only 84% of people recall ever having had back pain, which the authors explained by forgetfulness. They made the statement that data obtained by means of subjective statements should be handled with caution. Deyo RA, Rainville J, Kent DL (1992) What can the history and physical examination tell us about low back pain? JAMA 268:760 – 5 Excellent overview article on important findings during history taking and physical assessment. VroomenPC,deKromMC,WilminkJT,KesterAD,KnottnerusJA(2002)Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression. J Neurol Neurosurg Psychiatry 72:630 – 4 This paper deals with patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression. Various clinical findings were foundtobeassociatedwithnerverootcompressiononMRimaging,i.e.theteststended to have a lower sensitivity and specificity than previously reported. The straight leg raise test was not predictive. Most of the diagnostic information revealed by physical examina- tion findings had already been revealed by the history items. SprattKF,LehmannTR,WeinsteinJN,SayreHA(1990) A new approach to the low-back physical examination. Behavioral assessment of mechanical signs. Spine 15:96 – 102 This study systematically explores the test-retest reliability, a low-back physical examina- tion tool. Patients’ reports of pain location were quite stable across time but reports of History and Physical Examination Chapter 8 223 pain aggravation were generally less consistent across time than were later observed pain behaviors. Waddell G, McCulloch JA, Kummel E, Venner RM (1980)Nonorganicphysicalsignsin low-back pain. Spine 5:117 – 25 Landmark article on the clinical significance of non-organic signs in low-back pain. References 1. Anonymous (2004) New Zealand Acute Low Back Pain Guide. In: ACC Accident Compensa- tion Corporation, ed. Wellington, New Zealand 2. Badley EM (1995) The genesis of handicap: definition, models of disablement, and role of external factors. Disabil Rehabil 17:53–62 3. Bernhardt M, Bridwell KH (1989) Segmental analysis of the sagittal plane alignment of the normal thoracic and lumbar spines and thoracolumbar junction. Spine 14:717–21 4. Biering-Sorensen F, Hilden J (1984) Reproducibility of the history of low-back trouble. Spine 9:280 – 6 5. Cassidy JD, Carroll LJ, Cote P (1998) The Saskatchewan health and back pain survey. The prevalence of low back pain and related disability in Saskatchewan adults. Spine 23:1860–6; discussion 1867 6. Cote P, Cassidy JD, Carroll L (1998) The Saskatchewan Health and Back Pain Survey. The prevalence of neck pain and related disability in Saskatchewan adults. Spine 23:1689–98 7. D´ejerine (1914) S´emiologie du Syst`eme Nerveux. Paris: Masson 8. Deyo RA (1986) Early diagnostic evaluation of low back pain. J Gen Intern Med 1:328–38 9. Deyo RA, Rainville J, Kent DL (1992) What can the history and physical examination tell us about low back pain? JAMA 268:760–5 10. Deyo RA, Weinstein JN (2001) Low back pain. N Engl J Med 344:363 –70 11. Duus P, Bähr M, Frotscher M (2005) Topical diagnosis in neurology. Anatomy, physiology, signs, symptoms. Stuttgart: Thieme 12. Fairbank JC, Couper J, Davies JB, O’Brien JP (1980) The Oswestry Low Back Pain Disability Questionnaire. Physiotherapy 66:271–3 13. Fairbank JC, Hall H (1990) History taking and physical examination: Identification of syn- dromes of back pain. In: Weinstein JN, Wiesel SW, eds. The lumbar spine. Philadelphia: Saunders Company, 88–106 14. Grob D, Frauenfelder H, Mannion AF (2007) The association between cervical spine curva- ture and neck pain. Eur Spine J 16:669–678 15. Hart LG, Deyo RA, Cherkin DC (1995) Physician office visits for low back pain. Frequency, clinical evaluation, and treatment patterns from a U.S. national survey. Spine 20:11–9 16. IASP Task Force on Taxonomy (1994) Classification of chronic pain. In: Merskey H, Bogduk N, eds. Seattle: IASP Press, 209–214 17. Jarvik JG, Deyo RA (2002) Diagnostic evaluation of low back pain with emphasis on imag- ing. Ann Intern Med 137:586–97 18. Kosteljanetz M, BangF, Schmidt-Olsen S (1988) The clinical significance of straight-leg rais- ing (Lasegue’s sign) in the diagnosis of prolapsed lumbar disc. Interobserver variation and correlation with surgical finding. Spine 13:393–5 19. Margolis RB, Tait RC, Krause SJ (1986) A rating system for use with patient pain drawings. Pain 24:57–65 20. McCombe PF, Fairbank JC, Cockersole BC, Pynsent PB (1989) 1989 Volvo Award in clinical sciences. Reproducibility of physical signs in low-back pain. Spine 14:908–18 21. Melzack R (1987) The short-form McGill Pain Questionnaire. Pain 30:191–7 22. Million R, Hall W, Nilsen KH, Baker RD, Jayson MI (1982) Assessment of the progress of the back-pain patient 1981 Volvo Award in Clinical Science. Spine 7:204–12 23. Mooney V (1987) Impairment, disability, and handicap. Clin Orthop Relat Res:14–25 24. Nelson MA, Allen P, Clamp SE, de Dombal FT (1979) Reliability and reproducibility of clini- cal findings in low-back pain. Spine 4:97–101 25. Niemelainen R, Videman T, Battie MC (2006) Prevalence and characteristics of upper or mid-back pain in Finnish men. Spine 31:1846–9 26. Ransford A, Cairns D, Mooney V (1976) The pain drawing as an aid to the psychologic eval- uation of patients with low-back pain. Spine 1:127–134 27. Roland M, Morris R (1983) A study of the natural history of back pain. Part I: development of a reliable and sensitive measure of disability in low-back pain. Spine 8:141–4 28. Spratt KF, Lehmann TR, Weinstein JN, Sayre HA (1990) A new approach to the low-back physical examination. Behavioral assessment of mechanical signs. Spine 15:96–102 224 Section Patient Assessment 29. Strender LE, Sjoblom A, Sundell K, Ludwig R, Taube A (1997) Interexaminer reliability in physical examination of patients with low back pain. Spine 22:814–20 30. van Tulder M, Becker A, Bekkering T, Breen A, del Real MT, Hutchinson A, Koes B, Laerum E, Malmivaara A (2006) Chapter 3. European guidelines for the management of acute non- specific low back pain in primary care. Eur Spine J 15 Suppl 2:S169–91 31. Vaz G, Roussouly P, Berthonnaud E, Dimnet J (2002) Sagittal morphology and equilibrium of pelvis and spine. Eur Spine J 11:80–7 32. Viikari-Juntura E, Takala EP, Riihimaki H, Malmivaara A, Martikainen R, Jappinen P (1998) Standardized physical examination protocol for low back disorders: feasibility of use and validity of symptoms and signs. J Clin Epidemiol 51:245–55 33. Vroomen PC, de Krom MC, Wilmink JT, Kester AD, Knottnerus JA (2002) Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root com- pression. J Neurol Neurosurg Psychiatry 72:630–4 34. Waddell G (1987) Clinical assessment of lumbar impairment. Clin Orthop Relat Res:110–20 35. Waddell G, Allan DB,Newton M(1991) Clinical evaluation of disability inback pain. In: Fry- moyerJW,ed.Theadultspine:principlesandpractice.NewYork:RavenPress,155–168 36. Waddell G, Bircher M, Finlayson D, Main CJ (1984) Symptoms and signs: physical disease or illness behaviour? Br Med J (Clin Res Ed) 289:739–41 37. Waddell G, Main CJ (1984) Assessment of severity in low-back disorders. Spine 9:204–8 38. Waddell G, Main CJ, Morris EW, Di Paola M, Gray IC (1984) Chronic low-back pain, psycho- logic distress, and illness behavior. Spine 9:209–13 39. Waddell G, McCulloch JA, Kummel E, Venner RM (1980) Nonorganic physical signs in low- back pain. Spine 5:117–25 40. Walsh K, Coggon D (1991) Reproducibility of histories of low-back pain obtained by self- administered questionnaire. Spine 16:1075–7 History and Physical Examination Chapter 8 225 9 Imaging Studies Marius R. Schmid, Jürg Hodler Core Messages ✔ Standard radiographs obtained with the patient in the upright position represent the basis of imaging ✔ In standard radiography, the role of special views is decreasing because CT and MR imag- ing more easily provide relevant additional information ✔ MR imaging is the most commonly used advanced imaging method and is the method of choice in suspected disc abnormalities, tumors, infection, abnormalities of the spinal cord and other abnormalities ✔ MR imaging may occasionally be misleading because it demonstrates findings that are also found in asymptomatic individuals and – there- fore – may not be clinically relevant ✔ Intravenous contrast administration is useful in MR imaging of infection, systemic inflamma- tion, neoplasm, and vascular malformation and in postoperative imaging ✔ Advances can still be expected in MR imaging including fast whole-spine imaging, improved spatial resolution, spectroscopy, and functional imaging of the spinal cord ✔ CT retains an important role in assessment of trauma but may not reliably demonstrate disco- ligamentous injuries ✔ Ultrasonography has a limited role in imaging of the spine but may occasionally be indicated, such as for demonstration of paravertebral soft tissue abnormalities, vessels adjacent to the spine and for image guided interventions ✔ Bone scans are still useful for the assessment of bone abnormalities (activity of disease, staging for widespread disease, follow-up studies). The role of PET, PET-CT and SPECT-CT remains to be determined Imaging Methods Standard Radiographs Digital systems can reduce radiation dose and retakes Standard radiographs still represent the basis of spinal imaging. They can be obtained with a number of techniques: Conventional film/screen combination is an analogue technique which is still widely used in small hospitals and practi- tioners’ offices. Most radiology institutions, however, use digital systems, i.e., computed radiology (CR) systems or digital radiography (DR) systems CR systems are based on phosphor plates which are sensitive to X-ray beams. Theyareplacedincassetteswhicharesimilarindesignandsizetothecassettes used for the old film-screen systems. After exposure, the cassette is transferred to a digitizer which reads the latent information contained within the phosphor plate and provides a digital image in the widely used DICOM 3format(DICOM stands for Digital Imaging and Communications in Medicine). DICOM standard- izes the handling, storing and transmitting the information of medical images. Patient Assessment Section 227 DICOM images can be printed on hard copies or paper, or they can be distributed by a digital PACS (Picture Archiving and Communication System). Digital systems are becoming the new standard DR systems use flat panel detectors, which replace the cassettes used in film- screen and CR systems. They can be placed on existing classical radiographic tables, may be mounted on dedicated equipment or are available as portable devices. They directly acquire a digital image of high resolution after exposure. The image appears on a screen installed in the examination room and is visible within a few seconds while the patient is still available in the room for any repeat exposures. The images can then directly be sent to a PACS system,oralternatively they can be printed on film or paper. Because no cassettes have to be transferred, this system is much faster than film-screen or CR equipment. Similarly to CR, DR is less sensitive with regard to exposure errors than film-screen systems. Although the originally expected reduction in X-ray exposure has not been completely achieved, the digital systems allow some reduction of dose and reduce the number of repeat examinations. Patient positioning, beam angulation, film-focus and object-film distances are identical for all three methods. Lumbar Spine Standard radiographs (anteroposterior, lateral) remain the basic imaging studies Upright anteroposterior and lateral radiographs represent the basis of imaging of the lumbar spine. Film-focus distance typically is 115 cm for over-couch tubes with grid tables and 150 cm for vertical stands. The beam is centered 2 cm above the iliac crest. Additional radiographs are not routinely acquired because they have been replaced by magnetic resonance (MR) imaging or computed tomogra- phy (CT). The so-called Barsony projection has not been consistently described but typically consists of a radiograph centered at the sacrum (with a 15° to 20° caudocranial angulation of the beam (in order to be approximately perpendicu- lar to the sacrum and sacroiliac joints). Anteroposterior oblique radiographs with the entire patient rotated by 45° to both sides used to be employed for the demonstrationofspondylolysisbutareatleastinpartreplacedbyCT(“reversed angle” technique or sagittal reformatted images from thin sectioned axial source images). MR imaging may also be used for this purpose. Positional radiographs do not reliably demonstrate spinal instability Positional radiographs are typically obtained in the lateral projection with the spine in flexion and extension. For flexion radiographs, the patient is asked to bend forward with the pelvis in the center or slightly posterior to the center of the cassette. For extension radiographs, a back support is useful in order to allow the patient to lean backwards. The pelvis is located slightly anterior to the center of the film in extension radiographs. Lateral bending anteroposterior views are less commonly employed but may be useful for certain indications such as surgical planning in scoliosis. The role of positional radiographs in assessing instability has been debated due to a lack of consistent criteria for this diagnosis. Thoracic Spine In the thoracic spine, anteroposterior and lateral radiographs are most com- monly employed. They are centered at the middle of the thoracic spine with the superior border of the image at C7 level. Such radiographs are obtained with the patientintheuprightpositionifpossible.Deep inspiration during exposure of the lateral projection is recommended in order to render the density of the chest more even. Anteroposterior radiographs are exposed in expiration. If additional Imaging the thoracolumbar junction often requires a centered image imaging is required, radiographs centered at the thoracolumbar transition may be helpful. For the lateral view of the thoracolumbar transition, expiration is rec- ommended. 228 Section Patient Assessment Cervical Spine Specialized views can be diagnostic for cervical spine As for the other radiographs of the spine, anteroposterior and lateral images are typically employed. For lateral radiographs, weights (up to 10 kg on each side) may be placed in each hand of the patient in order to move the shoulders down- wards. Shoulder soft tissue overlap is most pronounced in heavy patients. The lateral swimmer’s view with the shoulders rotated out of the X-ray beam may The swimmer’s view demonstrates the cervicothoracic junction assist in the assessment of the cervicothoracic spine. This view is of importance in the evaluation of a traumatized patient in whom the cervicothoracic junction cannot be visualized by conventional views and in cases for which CT is not read- ily available. Anteroposterior oblique images better demonstrate the interverte- bral foramina and sometimes the facet joints. Anteroposterior transbuccal radiographs centered at the odontoid process are included in many standard imaging protocols at least after trauma and in patients with rheumatoid arthritis. Lateral positional radiographs are commonly obtained in flexion and extension in order to assess atlantodental instability. Whole Spine Radiographs Whole spine and lateral bending radiographs are associated with a relatively high radiation dose Whole spine radiographs are mainly employed for the diagnosis, follow-up and surgical planning of spinal deformity, particularly scoliosis. They are typically obtained with a film-focus distance of at least 2 m. This distance may be increased to up to 3 m. Radiation doses for this type of radiograph are relatively high with a mean effective dose of between 0.23 and 1.09 mSv per radiograph [16].Alowereffectivedosefortheanteroposteriorviewcomparedtothelateral view and a lower effective dose in male patients has been demonstrated [16]. The posteroanterior exposure supposedly results in a smaller dose to the sensitive breast tissue than an anteroposterior exposure. Lateral bending films are helpful in the assessment of scoliotic curve rigidity Lateral bending radiographs may be required for assessment of stiffness of the scoliotic spine. For comparison, mean effective doses for cervical spine radio- graphs are 0.18 mSv (anteroposterior) and 0.27 mSv (lateral); for thoracic spine radiographs they are 0.51 mSv (anteroposterior) and 0.80 mSv (lateral); and for lumbar spine radiographs they are 0.77 mSv (anteroposterior) and 1.7 mSv (lat- eral), respectively [43]. Magnetic Resonance Imaging MR Systems 3T scanners have several advantages including potentially superior image quality MR imaging is the second most commonly employed imaging method in assess- ing spinal disorders. In Europe and the United States, 1.5-Tesla scanners with tunnel-shaped, superconducting magnets are typically employed. Mid-field scanners with field strengths of 0.5 and 1.0 T are less commonly offered by the major manufacturers. On the other hand, high field scanners with 3.0 T or higher field strengths are increasingly being installed. A higher field strength has the advantage of a higher spatial resolution, a better signal-to-noise ratio and a shorter acquisition time. It is also advantageous in specialized imaging, includ- 3T scanners have the disadvantage of increased susceptibility and flow artifacts ing MR angiography, and functional imaging of the spinal cord. Disadvantages include increased susceptibility and flow artifacts. Susceptibility artifacts relate to local disturbances of the magnetic field and are more pronounced in high field scanners. They are most commonly encountered after surgery with metallic implants. Flow artifacts may be prominent in the vicinity of large vessels. Addi- tionally, patients in high field units are exposed to higher energy deposition (SAR: specific absorption rate). In order not to exceed acceptable SAR values, Imaging Studies Chapter 9 229 sequence parameters may have to be adapted, which may offset the physically possible shorter acquisition time [35]. Open MR systems allow claustrophobic patients to be imaged So-called open MR systems, usually based on permanent magnets, have rela- tively low field strength with typical values of 0.2–0.6 T, although lower and higher values are available. These magnets are open in the sense that the patients are not lying in a closed tunnel but rather between two horizontal plates which leave space on both sides of the patient as well as in the cranial and caudal direc- tion. The plate on top may be closer to the patient, however, than the top of the tunnel-like magnets. Permanent magnet systems are generally less expensive to purchase and operate than superconducting magnets but have disadvantages. Image quality and selection of specialized sequences tend to be inferior to those with mid to high field scanners. In addition, the magnet weight in such systems is higher than for superconducting systems, and open MR units are more suscep- tible to external sources influencing the magnetic field such as tramways and suburban trains. For adequate imaging, dedicated coils have to be employed for detection of MR signals For adequate imaging of the spine, dedicated coils have to be employed for detection of MR signals. A number of different designs are available which are placed underneath the body. With increasing distance from these surface coils, signal and image quality decrease. Therefore, these standard coils may not be sufficient for homogeneous images. Advanced designs which include both a dor- sal and a ventral element adapted to the body form are sometimes necessary and are routinely used for examinations of the cervical spine. MR Protocol for Spinal Imaging Various imaging protocols are used depending on the institution and the scanner type. No general recommendation can be given. However, the imaging parame- ters used at our center are given in Table 1. Table 1. MR imaging parameters Sequence Slice (mm) TR (ms) TE (ms) Flip angle Matrix FOV (mm) ETL NEX Time (min:s) Cervical spine T1 sagittal TSE 4 300– 600 <20 – 384×384 220–360 3 2 2:53 T2 sagittal TSE 2.5 3500–6 000 >100 – 512 × 512 220 – 360 23 2 3:41 T2* axial GE 2 9.3 4.7 70° 512×512 180 – 1 2:50 Ci3d Thoracic and l umbar spine T1 sagittal TSE 4 300– 600 <20 – 384×384 220–360 3 3 4:02 T2 sagittal TSE 4 3500–6000 >100 – 512 × 512 220 – 360 21 2 3:12 T2 axial TSE 4 3 500 –6000 >100 – 512×512 220 15 2 3:32 STIR sagittal TSE 4 3 800 TE 79 – 256×256 220–360 9 1 3:42 TI 170 Sacroiliac joint T1 coronal TSE 4 450 12 – 512 ×512 280 3 2 2:37 STIR coronal TSE 4 4950 69 – 256 ×256 280 9 1 4:23 T1 axial fs. Gd. TSE 5 570 10 – 384 × 384 250 3 2 3:44 STIR sagittal TSE 4 3 500 TR 70 - 384×384 360 9 1 3:14 TI 150 The above sequences are the routine spine MR protocols of Balgrist University Hospital, Zürich, Switzerland, acquired with a 1.5T MR unit (Avanto, Siemens, Medical Solutions, Erlangen, Germany) TSE = turbo spin-echo, GE = gradient-echo, Ci3d =3D CISS sequence, Me2d =2D MEDIC sequence, STIR =short tau inversion- recovery, TR =repetition time, TE =echo time, TI =inversion time, FOV =field of view, ETL =echo train length, NEX =number of excitations, fs. =fat saturated, Gd. =after i.v. injection of MR contrast agent (gadolinium) 230 Section Patient Assessment . thigh and legs, and determination of sensory changes in the leg [20]. History and Physical Examination Chapter 8 221 Differential Diagnosis of Spinal Pain Syndromes The differential diagnosis of spinal. eval- uation of patients with low-back pain. Spine 1:127–134 27. Roland M, Morris R (1983) A study of the natural history of back pain. Part I: development of a reliable and sensitive measure of disability. disor- ders, and renal and gastrointestinal disorders. Jarvik and Deyo differentiate non- mechanical spinal conditions and visceral disease ( Table 8)frommechanical low-back pain in the differential diagnosis