Best Practice & Research Clinical Rheumatology
Volume 17, Issue 1 , Pages 17-32, February 2003

Imaging modalities for identifying the origin of regional musculoskeletal pain

  • Walter Grassi, md (Full Professor)

      Affiliations

    • Corresponding Author InformationCorresponding author. Tel.: +39-0-731-534-133; Fax: +39-0-731-534-124. E-mail address: walter.grassi@unian.it(W. Grassi)

Clinica Reumatologica, Università degli Studi di Ancona, Ospedale ‘A. Murri’, Via dei Colli, 52. 60035 Jesi (Ancona), Italy

Istituto di Radiologia, Università degli Studi di Ancona, Ospedale Regionale Torrette, Via Tronto, 60100 Ancona, Italy

Clinica Reumatologica, Università degli Studi di Ancona, Ospedale ‘A. Murri’, Via dei Colli, 52. 60035 Jesi (Ancona), Italy

Received 1 September 2002; accepted 1 September 2002.

Article Outline

Abstract 

Regional musculoskeletal pain is one of the most common complaints in daily rheumatological practice. Conventional radiology remains the cornerstone of diagnostic imaging in these patients despite the advent of new, fascinating imaging techniques. Ultrasonography may have a relevant impact on final diagnosis or therapeutic choices. It is highly sensitive to the identification of fine, soft-tissue changes and it should be considered as an integral part of the clinical examination in most patients. Scintigraphy is indicated when multifocal processes have to be excluded and when high sensitivity is required. Computed tomography is an excellent tool for the assessment of osseous based abnormalities. Magnetic resonance has several characteristics of the ideal diagnostic tool. However, its appropriateness in the evaluation of many regional musculoskeletal conditions is a matter for discussion. An appropriate diagnostic programme for patients with regional musculoskeletal pain has to be focused on the strengths and weaknesses of various imaging techniques.

Keywords:  regional musculoskeletal pain, conventional X-ray, ultrasonography, computer tomography, magnetic resonance, scintigraphy, thermography

 

Regional musculoskeletal pain is a leading cause of rheumatological consultations. The precise cause of pain may remain obscure in some patients and in some circumstances a firm diagnosis may not be achieved. However, an anatomical diagnosis should always be done in these patients because knowing the source of pain may be an essential component in determining the most appropriate treatment plan.

Over the last two decades, advances in imaging modalities have allowed an earlier detection of fine anatomical changes and a more accurate quantification of the extent of various diseases.1., 2.

We now have a wide range of imaging modalities, making possible an ever earlier diagnosis. These modalities include conventional X-ray, digital radiology, ultrasonography (US), conventional scintigraphy, computed tomography (CT), magnetic resonance imaging (MRI), and some specific applications of the main techniques, such as colour Doppler US, power Doppler US, triphasic scintigraphy, single-photon emission computed tomography (SPECT), CT arthrography and MR arthrography. It is clearly evident that the choice between all of these imaging methods in the evaluation of regional musculoskeletal pain may be puzzling. As a general rule, it should be stressed that this choice is never absolute and usually depends on several factors, including the suspected abnormality, the availability of the techniques locally, the skills and experience of those performing the examination, the waiting list, specific contraindications, and the patient's age.

A combination of several imaging methods may be needed for accurate assessment of some specific targets, and this can make the definition of a standardized approach to specific clinical problems still more complex.

Before planning an imaging modality we should have a clear understanding of what to do with the information that is supplied rather than a failure to provide that information.3 A very accurate history taking, a clear definition of diagnostic targets, and a deep knowledge of the strengths and weaknesses of each imaging modality form the basis for cost-effective use of the various imaging methods. The prompt and correct use of the most appropriate imaging technique may mean that other examinations can be avoided. The best strategy may ultimately be a multifaceted and flexible approach that should be based on recommendations and guidelines.

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1. Conventional X-ray 

Conventional radiology remains the cornerstone of diagnostic imaging despite the advent of new, fascinating imaging techniques. It should be regarded as the first-line imaging modality in the evaluation of regional musculoskeletal pain. Plain films still have the greatest influence on clinical decision making, patient treatment, and outcome.4., 5., 6. Ready availability, relatively low cost, and the absence of a need for specialized equipment or diagnosticians are the main advantages of conventional radiology.

Conventional radiology may give us an immediate cheap solution to the diagnostic dilemma of regional muscoloskeletal pain by providing imaging findings highly suggestive for diagnosis. Key diagnostic findings on conventional X-ray include aggregates of calcium pyrophosphate crystals in patients with acute monoarticular arthritis, periostosis in patients with bone burning pain (Figure 1), heterogeneous demineralization in patients with algodystrophy, Looser zones (pseudofractures) in osteomalacia. A basic concept to keep in mind is that one or more abnormalities clearly evident in a plain radiograph may not be necessarily related to the main clinical findings. Degenerative changes typical of osteoarthritis are the main deceptive findings.

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  • Figure 1. 

    Forearm radiograph showing a typical periostosis in a patient with bone burning pain. Final diagnosis: hypertrophic osteoarthropathy associated with lung cancer.

The use of a conventional X-ray which is the major source of radiation, appears to occur too early and too frequently in several clinical conditions. During the acute back pain episode, 46% of patients had radiography.7 Much of this routine roentgenography is used inappropriately and a more conservative approach to the diagnostic evaluation of acute back pain, as well as other regional pain conditions, is advisable. Box 1

Box 1. Practice points

•there are few exceptions to the rule that plain film radiographs should be assessed before planning other imaging modalities

•a plain radiograph is not a necessary part of the initial diagnostic approach to patients with regional musculoskeletal pain

•comparative assessment of the unaffected side should always be performed

•the risk of radiation must never be underestimated, especially in younger patients

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2. Ultrasonography 

Ultrasonography (US) has evolved rapidly over the last few years and there has been substantial growth in its applications to differential diagnosis of regional musculoskeletal pain.8., 9., 10., 11. It is a highly sensitive tool for the identification of fine, soft-tissue changes and is especially useful in the context of a confusing clinical and radiographic setting. US has proved to be of value in the diagnosis of several rheumatic conditions such as early rheumatoid arthritis, psoriatic arthritis, crystal deposition diseases, osteoarthritis, rotator cuff tear, bursitis, tendinitis and tenosynovitis, carpal tunnel syndrome, amyloidosis, Tietze's syndrome, rib fractures and Morton neuroma.12., 13., 14., 15.

The correct place of US in the diagnostic procedures of patients with regional pain may be widely variable depending on whether the examination is carried out by the rheumatologist, by the radiologist (as in most cases in Europe), or by technicians who perform the entire study without supervision and make a hard-copy record or videotape of their findings for a physician to report later (as happens in North America).16 The information provided by US differs from that obtained with other imaging modalities because it is the most operator-dependent technique. Thus, the interpretation of sonographic pictures is dependent on the technical conditions of the examination and the abilities of the examiner.

Where the rheumatologist personally performs US examination, the source of pain may be much more easily identified because of the comprehensive analysis of anamnestic data, objective clinical findings and morphostructural evaluation of the anatomical area involved. The main practical advantages arising from the combined clinical and sonographic assessment include making a definitive diagnosis at the moment of the first clinical approach possible (e.g. Achilles tendonitis with partial tendon tear instead of the generic definition of Achilles tendinopathy, or subdeltoid bursitis instead of shoulder periarthritis) and the possible avoidance of further diagnostic procedures.

Although the impact of US on final diagnosis or therapy monitoring has not yet been defined, over the last few years an increasing number of rheumatologists have started to utilize ultrasound in their daily clinical practice and there is now considerable evidence that the role of US imaging in diagnosing and monitoring musculoskeletal diseases is growing year by year and that US routinely performed by rheumatologists should be encouraged. However, many issues must be addressed to allow further development of this field within our speciality, including the establishment of adequate training programmes.17

The main advantages of US, with respect to other imaging techniques, include absence of radiation, good visualization of the joint cavity, low running costs, multiplanar imaging capability, quantification of soft-tissue abnormalities. Moreover, US is rapidly performed and readily accepted by patients.

US may also be used to assist needle positioning within the selected target area and to facilitate arthrocentesis. It should precede and guide local injection therapy whenever possible, especially in anatomical areas at risk of potential damage by the sharp point of the needle.18., 19., 20.

High-quality musculoskeletal US requires high-quality sonographic systems. Optimal ultrasound equipment for musculoskeletal investigations should be equipped with standard 7.5–10MHz transducers for conventional examination. Higher frequency transducers (13–28MHz) are necessary to depict fine details of superficial tissues. Power Doppler adds substantial advantages to standard US assessment by allowing the evaluation of soft-tissue hyperaemia and is of practical value in distinguishing inflammatory and infectious musculoskeletal fluid collections from those that are non-inflammatory. It would seem to be a very promising tool for monitoring disease activity.

Operator dependency, limited field of view of some anatomical areas due to the lack of adequate ‘acoustic windows’, and the long learning curve are the main shortcomings of US.

High-resolution US clearly depicts fine anatomical details. This means that some abnormalities (i.e. minimal synovial fluid collections, tendon microcalcifications, and irregularities of bone profile) can be seen in asymptomatic subjects. Interpretations of these changes require skill and strict criteria. All sonographic findings should be carefully evaluated on the basis of the clinical examination.

2.1. Ultrasonography and tendon pain 

Several patterns of tendon involvement can be detected by US in patients with localized pain. They include tendon sheath widening, loss of the normal fibrillar echotexture (interruption, fragmentation and disappearance), irregularity of the tendon margin (irregular and/or blurred contour of the tendon), peritendinous oedema, diffuse or focal hypoechoic areas inside the tendon, diffuse or focal tendon thickening, and discontinuity of the tendon (partial or complete tendon tear) (Figure 2). Focal or diffuse hypoechoic areas inside the tendon always reflect a pathological process causing tendon degeneration and/or intratendinous tear. Focal or confluent hypoechoic regions may contain synovial fluid, fat, blood, or proteinaceous material.21

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  • Figure 2. 

    (A) Achilles tendon. Partial tendon rupture in a patient treated with ciprofloxacin. (B) Partial Achilles tendon rupture and retrocalcaneal bursitis (rb) in a marathoner. (C) De Quervain's disease. Exudative tenosynovitis of the first compartment of the extensor tendons. (D) Periarthritis of the shoulder. Subdeltoid bursitis and biceps tenosynovitis. ∗, synovial fluid; arrowheads, bicipital groove.

Soft-tissue surrounding tendons may show a hypoechoic pattern, indicating peritendinous inflammation (Figure 3). It is often associated with a homogeneous, clearly evident, and full-thickness widening of extra-articular and peritendinous soft tissues.

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  • Figure 3. 

    Seronegative spondyloarthopathy. Calcaneal bone (cb). Longitudinal (A) and transverse (B and C) dorsal scans at the insertion of the Achilles tendon show a retrocalcaneal bursitis (*) and bone erosions (solid white circle).

The search for features of tendon pathology is particularly important in patients with shoulder pain. US may be the most cost-effective test for the approach to these patients.22., 23. The underlying anatomical lesions that can be sonographically detected include: biceps tenosynovitis, dislocation of the biceps tendon, tendonitis of the supraspinatus tendon, subdeltoid bursitis, calcific tendonitis and rotator cuff. US of the rotator cuff requires an experienced ultrasonographer.

Acute or chronic Achilles tendon pain is a specific indication for US that can reveal a wide variety of abnormalities typical of tendonitis and/or tendinosis. The typical sonographic appearance of Achilles tendinosis is characterized by areas of altered echogenicity. Contour defects (blurring of the tendon margins), loss of the normal fibrillar echotexture, and intratendinous calcifications are frequent findings in patients with chronic tendinitis, post-traumatic tendinopathy, and degenerative tendon changes occurring in association with metabolic disorders (i.e. diabetes mellitus and heterozygous familial hypercholesterolaemia). Detection of intratendinous alteration ranging from a focal appearance of fibrillar interruption to a diffuse blurring of the tendon texture may be an important diagnostic clue to the presence of a low mechanical resistance.

2.2. Ultrasonography and joint pain 

Sonographic assessment of joint space is an exciting experience for clinical rheumatologists. US can detect several anatomical abnormalities, including joint space widening, fluid collection, synovial hypertrophy, cartilage defects, bone erosions and calcifications (Figure 4).24 Joint space widening is the most characteristic feature of synovitis. Joint effusion and synovial proliferation can easily be distinguished. Proliferative synovitis is characterized by clusters of soft echoes (bushy and villous appearance) and/or homogeneous synovial thickening.

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  • Figure 4. 

    (A) Psoriatic arthritis. Sausage finger. Longitudinal volar scan showing exudative synovitis of the proximal interphalangeal joint. (B) Reactive arthritis. Hip joint synovitis. (C) Septic arthritis of a metacarpophalangeal joint. The solid white circle indicates a wide area of bone resorption. (D) Gout. Longitudinal dorsal scan of the first metatarsophalangeal joint. ∗, synovial fluid; mp, middle phalanx; pp, proximal phalanx; a, acetabular bone; f, femur; mc, metacarpal head; mt, metatarsal head.

The hyaline articular cartilage appears as a sharply defined hypo-anechoic layer. Several cartilage abnormalities can be observed in various rheumatic disorders. These include loss of cartilage transparency, loss of the sharpness of the cartilage-soft tissues interface, cartilage erosions and cartilage thinning. Various combinations of these changes are clearly detectable in osteoarthritis.

Of interest is that small bone erosions can be detected by US even in patients without evident bone changes on conventional X-rays.

Isolated knee pain of recent onset is a frequent clinical problem in an outpatient rheumatology setting. US can provide some relevant diagnostic information by identifying several possible anatomical sources of the pain, including joint cavity widening, bursitis, meniscal cysts, tendon pathology and ligament lesions.

US, in particular, may provide useful information for the rheumatologist in patients with anterior knee pain by depicting the underlying anatomical status of patellar tendon and surrounding soft tissues. Several sonographic abnormalities of patellar tendon echotexture can be depicted: anechoic interruption of the typical fibrillar pattern, hypoechoic areas inside the tendon, hyperechoic dots without acoustic shadow, and hyperechoic bands generating acoustic shadow. Bursal involvement may range from a thin anechoic widening to a large fluid collection, with or without synovial proliferation. Sports requiring repetitive violent contraction of quadriceps muscles expose athletes to a higher risk for developing ‘jumper's knee’ or patellar tendon tendinosis. In these cases, US may be helpful in detecting relatively asymptomatic pathological changes of the patellar tendon, which may lead to severe patellar tendinopathy.

In patients with hip pain, US allows a quick assessment of the joint features. Synovitis in the hip joint is difficult to evaluate clinically. An increased distance between the hip joint capsule and the femur is the sonographic hallmark of synovitis. In healthy subjects, sonographic distance between the iliofemoral ligament and femoral neck ranges between 4 and 9mm. A distance of more than 9mm or a difference of more than 1mm between the two sides supports a diagnosis of synovitis.25 US also allows the recognition of other sources of hip pain such as ileopsoas bursitis, haematomas and hamstrings tendonitis.

2.3. Ultrasonography and carpal tunnel syndrome 

US allows a detailed examination of the median nerve and flexor tendons inside the carpal tunnel. In patients with symptoms suggestive for a carpal tunnel syndrome, US is able to detect several abnormalities of the nerve (enlargement of the cross-sectional area, oedema contour deformity) and tendon (tendon sheath widening).26 It has recently been demonstrated that carpal tunnel syndrome can be identified by US less sensitively but more specifically than by nerve conduction study.27

2.4. Ultrasonography and bursitis 

Bursitis, Baker's cyst and other synovial cysts are easily detected by US because of the increase of the synovial fluid that usually appears as a sharply defined anechoic area.

The echogenicity of the fluid collection is related to the underlying disease and to the disease duration (Figure 5).

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  • Figure 5. 

    (A) Polymyalgia rheumatica. Exudative subdeltoid bursitis. (B) Calcium pyrophosphate dihydrate deposition disease. Subdeltoid bursitis. (C) Rheumatoid arthritis. Popliteal cyst. (D) Septic subdeltoid bursitis. ∗, synovial fluid; arrowhead, synovial hypertrophy.

Septic synovitis, haematic collection and chronic synovitis are characterized by a relevant variability of the echostructural pattern ranging from the diffuse soft echogenicity of septic synovitis to the coexistence of echoic synovial thickening and anechoic areas in patients with chronic arthritis.

Even small and clinically unsuspected fluid collections can be detected by sonographic examination. US can be helpful in differentiating Baker's cysts from other masses in the popliteal space, such as popliteal artery aneurysms and soft-tissue tumours (i.e. lymphoma, liposarcoma, neurofibrosarcoma).Box 2Box 3

Box 2. Practice points

•US is an extension of the clinical examination to otherwise inaccessible anatomical structures

•by combining multiplanar imaging capabilities, the impressive spatial resolution of very-high-frequency probes (<0.04mm), and power Doppler, it is possible to depict very early morpho-functional changes of the painful areas

•US may be a cheaper and more effective alternative to MRI in several clinical conditions

•great care should be taken to avoid misinterpretation of subtle sonographic changes in asymptomatic subjects

Box 3. Research agenda

•a better standardization of indications for musculoskeletal imaging is a major task for researchers

•education and training on musculoskeletal US have to be planned by defining the minimal requirements for a specific core curriculum

•three-dimensional technology and sonographic contrast media may open new exciting areas of application of US in early diagnosis and therapy monitoring

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3. Thermography 

Thermography is a very interesting and probably underused and underevaluated imaging method. It allows us to depict the temperature differences and subtle temperature gradients in the explored areas by recording infrared radiation emitted by the body. It is regarded as a very sensitive test (90% accuracy) in the diagnosis of reflex sympathetic dystrophy. Thermography may provide useful information in the assessment of enthesitis (hot spots at the insertional areas).

The relatively high cost of good-quality equipment, the lack of specificity of thermographic maps and the lack of an adequate number of clinical studies are the main limitations of the method, which has a limited diffusion.

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4. Scintigraphy 

When a bone abnormality is suspected or multifocal processes have to be excluded, scintigraphy may be considered as a first-line imaging test. It can also play a relevant role in clarifying the significance of radiographic findings.

Scintigraphy is an objective and very sensitive tool for detecting inflammation and judging its activity, especially in structures that are not readily accessible to physical examination. Negative joint scan accurately excludes active arthritis in patients with persistent arthralgia.28

The influence of scintigraphy on clinical decision making may be relevant in patients with either acute or chronic low back pain.

Bone scintigraphy has also proved to be an excellent tool in the depiction of very early stages of avascular necrosis. These stages appear as a cold spot due to diminished blood supply. As the disease progresses, and bone remodelling begins, increasing uptake occurs in the affected area and the cold spot becomes a hot spot. It has to be kept in mind that there is a period of time between these two phases (the cross-over point) when scintigraphy can produce a false-negative result.28

The use of SPECT has resulted in increased sensitivity and specificity compared with planar bone scintigraphy. Compared with standard scintigraphy, SPECT allows more accurate anatomical localization of increased uptake. Tomographic reconstructions provide a more precise display of tracer accumulation, which helps to differentiate structures that would otherwise overlap on planar images.29 This specific aspect of the method may play a key role in identifying conditions such as facet joint syndrome.

The wide spectrum of conditions that can be identified with the remarkable support of scintigraphy also includes primary bone tumours, metastases, osteoma osteoid, osteomyelitis, reflex sympathetic dystrophy, Tietze's syndrome, Paget's disease, periostitis and hypertrophic osteoarthropathy (Figure 6).

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  • Figure 6. 

    Scintigraphic patterns in different conditions clinically characterized by regional pain. (A) Increased uptake on the sternoclavear joint in a patient with early psoriatic arthritis. (B) Paget's disease of the tibial bone. (C) Periostosis associated with hypertrophic osteoarthropathy.

Scintigraphy exposes patients to ionizing radiation, is expensive, and is time consuming for the patient. The need for special facilities, relatively poor resolution and lack of specificity are the other main disadvantages of this otherwise very useful imaging method. Box 4

Box 4. Practice points

•bone scan is indicated when a comprehensive approach to a regional pain requires an assessment of the whole skeleton

•scintigraphy may detect some bone lesions not seen by MRI (e.g. avascular necrosis, bone infarcts)

•scintigraphy should be regarded as a key diagnostic step in early detection of stress fractures

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5. Computed tomography 

Computed tomography (CT) is an excellent tool for assessment of osseous based abnormalities. Multiplanar and three-dimensional reconstructions provide exquisite anatomical detail. Musculoskeletal imaging has significantly improved with multislice CT–which allows extended anatomical coverage with thin slices. It also facilitates scanning of obese patients as well as patients with metal hardware. A volumetric image set with isotropic properties can be obtained in a single acquisition with a 0.5mm slice width.30 CT is a useful tool for evaluating axial structures and complex joints (e.g. spine, subtalar joints, sacroiliac joints).

The decision whether to use CT or MR imaging for evaluation of trauma may be problematic.

CT is the method of choice for showing bone abnormalities such as bone destruction due to malignancy, infection or spinal canal stenosis. Other indications for CT include the detection of loose bodies and disc pathology. A suspected failed back surgery is another specific indication for CT because of its ability to differentiate scar from recurrent disc herniation. In patients with suspected osteoid osteoma, CT may provide highly specific imaging findings (Figure 7).

In the assessment of trauma, the role of CT is to allow accurate definition of the extent of fractures and to depict intra-articular fragments that are not visualized at conventional radiography.

CT is substantially overused in patients with acute low back pain. Due to the relatively high radiation exposure it should be performed in the assessment of regional musculoskeletal pain only when it is expected to add valuable information to clinical history, physical examination and other safer diagnostic procedures. Box 5

Box 5. Practice points

•CT may be superior to MRI in some conditions, such as sternoclavicular arthritis and sacroiliitis

•CT is associated with significant X-ray exposure. In terms of radiation dosage (mSv) a conventional CT of the lumbar spine corresponds to >200 chest X-rays

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6. Magnetic resonance imaging 

Magnetic resonance imaging (MRI) has, at the moment, several characteristics of the ideal imaging technique for the evaluation of most regional musculoskeletal disorders. The magnets are now stronger, and scanners have become more sensitive and better able to detect even minimal anatomical and functional changes. High sensitivity in detecting numerous radiographically occult abnormalities, lack of ionizing radiation, anatomical detail, and functional information are only some aspects of the remarkable strength of MRI. It can give us detailed information concerning the source of pain and the nature and severity of the tissue abnormalities. Because the clinical diagnosis of regional musculoskeletal pain may be equivocal, MRI has proved to be the modality of choice, following plain radiography, for imaging a number of disease processes such as osteonecrosis, many musculoskeletal tumours, marrow replacement processes, osteomyelitis, and bone trauma. MRI can detect bone erosions and active synovitis long before the changes are visible on conventional radiographs.31 Thus, it can be of great value for differentiating cases of early rheumatoid arthritis from those of other diseases with joint manifestations.

The accuracy of MRI is dependent on technical factors, such as magnet field strength, surface coils, and sequence selection.

Timing of examination is another relevant aspect for a precise diagnosis because MRI findings are dependent on the stage of the disease.

A specific advantage of MR in the assessment of patients with low back pain and/or lumbar radiculopathy is its ability to show the whole lumbar spine and thoracolumbar junction, including the lower cord, thereby ensuring that unsuspected proximal lesions are not overlooked.32., 33., 34., 35.

MRI is the most sensitive technique for detecting osteonecrosis of the femoral head.36 In patients with isolated knee pain, MRI may play a key role in differentiating inflammatory, traumatic and degenerative conditions. It enables accurate assessment of meniscal and ligamentous lesions, and is particularly useful in the initial assessment of patients with suspected internal derangement of the knee. Other suspected knee disorders that can be accurately depicted by MRI include chondromalacia patellae and osteochondritis dissecans, plica syndrome.37 Moreover, MRI provides a careful evaluation of the numerous bursae surrounding the knee and an easy diagnosis of bursitis that can mimic intra-articular pathology.

Shoulder pain is another key target of MRI. It provides an extremely accurate map of the extent of anatomical lesions in patients with persistent shoulder pain and may play a key role in detecting the exact site of impingement, thus allowing accurate pre-operative planning for possible surgery patients. Tendonitis and partial tear within the supraspinatus can be accurately detected, as can glenoid labral tears. Loss of tendon integrity may be revealed by abnormal high signal intensity, abnormal shape (thin, thick, irregular), and discontinuity.

MRI is also an effective procedure for assessing patients with chronic wrist pain. It is particularly indicated in the evaluation of triangular fibrocartilage and the intrinsic and extrinsic ligaments.

MR arthrography can be extremely useful for detecting overlooked abnormalities such as meniscal tears in patients with knee pain and labral tears in patients with shoulder or hip pain.

Future applications of MRI include the assessment of response to treatment.

Although MRI is a dream tool to solve some otherwise very complex problems, its appropriateness in the evaluation of many regional musculoskeletal conditions is a matter for discussion. In certain instances, we have an information overload–raising questions about the clinical significance of some abnormalities and the direct relationship with the symptoms. Focal bone marrow oedema, for example, can be detected in several conditions, including osteoarthritis and seronegative spondyloarthritis (Figure 8). These changes are generated by inflammatory infiltration and fibrosis. It is not clear whether these areas have to be considered as sources of pain or are predictive of disease progression.2 It has to kept in mind that about one patient in five who is booked for an MRI examination will, for reasons of non-attendance, fear, pain, pacemaker, intra-ocular metal fragment, deformity, or sheer bloody-mindedness, not end up with a wholly diagnostic scan.3Box 6

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  • Figure 8. 

    MRI appearance of early peripheral involvement in a patient with seronegative spondyloarthropathy. An extensive and clearly evident oedema of the calcaneal bone is an otherwise undetectable finding in a patient with suspected enthesitis.

Box 6. Practice points

•MRI should be performed when regional pain may be a suspected harbinger of potentially severe anatomical damage and other imaging modalities are not an acceptable alternative

•MRI has an impressive diagnostic potential in most regional musculoskeletal disorders but its use is often precluded in clinical practice because of several limitations such as high cost, waiting list, and lack of adequate expertise

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7. Summary 

An appropriate diagnostic programme for patients with regional musculoskeletal pain has to be focused on the strengths and weaknesses of various imaging techniques concerning the specific clinical hypothesis.

US is increasingly used in rheumatological practice as a part of the clinical examination in patients with regional pain. The reliability of US imaging depends on equipment, technique, and the experience of the examiner.

Over the last 10 years, a dramatic improvement in early and accurate documentation of the anatomical bases of musculoskeletal has taken place. However, habit, plain ignorance and legal threats are at the basis of the too frequent inappropriate use of diagnostic imaging in the evaluation of regional musculoskeletal pain. Although ideally comprehensive guidelines cannot be prepared on such a wide and controversial matter, a major effort should be dedicated to a better standardization of indications for musculoskeletal imaging, the choice of procedures, and, equally importantly, the limitations.

In an era of cost containment it is mandatory to have a working knowledge of indications of the different imaging techniques in order to avoid inappropriate use. This is particularly true for expensive and/or invasive techniques that are not justifiable if they are not expected to add a relevant improvement to the sensitivity and specificity of clinical assessment and/or of first-line imaging modalities (X-ray, US). Precise cost–benefit ratios related to the use of high-technology imaging are hard to find.

Avoiding equivocal or inappropriate use of the various imaging modalities is a major task for rheumatologists and radiologists.

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References 

  1. Peterfy CG. Imaging techniques. In:  Klippel JH,  Dieppe PA editor. Rheumatology. 2nd ed.. London: Mosby; 1998;p. 2.14.1–2.14.18
  2. Peterfy CG, Genant HK. Magnetic resonance imaging in arthritis. In:  Koopman WJ editors. Arthritis and Allied Conditions. 14th ed.. Philadelphia: Lippincott, Williams and Wilkins; 2001;p. 118–154
  3. Butt WP. MRI of the appendicular skeleton. British Journal of Rheumatology. 1993;32:945–946
  4. Bohndorf K, Schalm J. Diagnostic radiography in rheumatoid arthritis: benefits and limitations. Baillière's Clinical Rheumatology. 1996;10:399–407
  5. Kransdorf MJ, Murphey MD. Radiologic evaluation of soft-tissue masses. A current perspective. American Journal of Roentgenology. 2000;175:575–587
  6. Vignon E, Conrozier T, Piperno M, et al.  Radiographic assessment of hip and knee osteoarthritis. Recommendations: recommended guidelines. Osteoarthritis and Cartilage. 1999;7:434–436
  7. The North Carolina Back Pain Project Carey TS, Garrett J. Patterns of ordering diagnostic tests for patients with acute low back pain. Annals of Internal Medicine. 1996;125:807–814
  8. Grassi W, Cervini C. Ultrasonography in rheumatology: an evolving technique. Annals of the Rheumatic Diseases. 1998;57:268–271
  9. Balint P, Sturrock RD. Musculoskeletal ultrasound imaging: a new diagnostic tool for the rheumatologist?. British Journal of Rheumatology. 1997;36:1141–1142
  10. Manger B, Kalden JR. Joint and connective tissue ultrasonography–a rheumatologic bedside procedure? A German experience. Arthritis and Rheumatism. 1995;38:736–742
  11. Backhaus M, Burmester G-R, Gerber T, et al.  Guidelines for musculoskeletal ultrasound in rheumatology. Annals of the Rheumatic Diseases. 2001;82:641–649
  12. Gibbon WW. Musculoskeletal ultrasound. Baillière's Clinical Rheumatology. 1996;10:561–588
  13. Wakefield RJ, Gibbon WW, Emery P. The current status of ultrasonography in rheumatology. Rheumatology. 1999;38:195–201
  14. Iagnocco A, Coari G, Palombi G, Valesini G. Sonography in the study of metatarsalgia. Journal of Rheumatology. 2001;28:1338–1340
  15. Mariacher-Gehler S, Michel BA. Sonography: a simple way to visualize rib fractures. American Journal of Roentgenology. 1994;163:1268
  16. Chan V, Hanbidge A, Wilson S, et al.  Case for active physician involvement in US practice. Radiology. 1996;199:555–560
  17. Speed CA, Bearcroft PW. Training in musculoskeletal sonography: report from the first BSR course. Rheumatology. 2002;41:241–242
  18. Grassi W, Farina A, Filippucci E, Cervini C. Intralesional therapy in carpal tunnel syndrome: a sonographic-guided approach. Clinical and Experimental Rheumatology. 2002;20:73–76
  19. Grassi W, Farina A, Filippucci E, Cervini C. Sonographically guided procedures in rheumatology. Seminars in Arthritis and Rheumatism. 2001;30:347–353
  20. Koski JM. Ultrasound guided injections in rheumatology. Journal of Rheumatology. 2000;27:2131–2138
  21. Grassi W, Filippucci E, Farina A, Cervini C. Sonographic imaging of tendons. Arthritis and Rheumatism. 2000;43:969–976
  22. Naredo E, Aguado P, De Miguel E, et al.  Painful shoulder: comparison of physical examination and ultrasonographic findings. Annals of the Rheumatic Diseases. 2002;61:132–136
  23. Bruyn GA, Rijnks J, den Hollander H, et al.  Comparison of sonography and arthroscopy in patients with shoulder complaints (abstract). Arthritis and Rheumatism. 1999;42(9):S270
  24. Grassi W, Filippucci E, Farina A, Cervini C. Sonographic imaging of the distal phalanx. Seminars in Arthritis and Rheumatism. 2000;29:379–384
  25. Sada PN, Rajan P, Jeyaseelan L, Washburn MC. Standards for ultrasonographic measurements of the hip joint in Indian adults. Skeletal Radiology. 1994;23:111–112
  26. Lee D, van Holsbeeck MT, Janevski PK, et al.  Diagnosis of carpal tunnel syndrome. Ultrasound versus electromyography. Radiology Clinics of North America. 1999;37:859–872
  27. Swen WA, Jacobs JW, Bussemaker FE, et al.  Carpal tunnel sonography by the rheumatologist versus nerve conduction study by the neurologist. Journal of Rheumatology. 2001;28:62–69
  28. Ryan PJ, Fogelman I. Isotope imaging. Baillière's Clinical Rheumatology. 1996;10:589–613
  29. De Maeseneer M, Lenchik L, Everaert H, et al.  Evaluation of lower back pain with bone scintigraphy and SPECT. Radiographics. 1999;19:901–912
  30. Buckwalter KA, Rydberg J, Kopecky KK, et al.  Musculoskeletal imaging with multislice CT. American Journal of Roentgenology. 2001;176:979–986
  31. Sugimoto H, Takeda A, Hyodoh K. Early-stage rheumatoid arthritis: prospective study of the effectiveness of MR imaging for diagnosis. Radiology. 2000;216:569–575
  32. Ackerman SJ, Steinberg EP, Bryan RN, et al.  Trends in diagnostic imaging for low back pain: has MR imaging been a substitute or add-on?. Radiology. 1997;203:533–538
  33. Brant-Zawadzki MN, Dennis SC, Gade GF, Weinstein MP. Low Back Pain. Radiology. 2000;217:321–330
  34. Oostveen JC, van de Laar MA. Magnetic resonance imaging in rheumatic disorders of the spine and sacroiliac joints. Seminars in Arthritis and Rheumatism. 2000;30:52–69
  35. Heron CW. Magnetic resonance imaging in rheumatology. Annals of the Rheumatic Diseases. 1991;51:1287–1291
  36. Conway WF, Totty WG, McEnery KW. CT and MR imaging of the hip. Radiology. 1996;198:297–307
  37. Tavernier T, Dejour D. Knee imaging: what is the best modality. Journal of Radiology. 2001;82:387–405

PII: S1521-6942(02)00099-2

doi:10.1016/S1521-6942(02)00099-2

Best Practice & Research Clinical Rheumatology
Volume 17, Issue 1 , Pages 17-32, February 2003

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