Complete resolution and remodeling of chronic recurrent multifocal osteomyelitis on MRI and radiographs.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare condition thought to be under-diagnosed, with a true prevalence of more than the 1 in 10,000 estimated. It is a condition that is classically described as polyostotic with a relapsing and remitting course, preferentially affecting the metaphyses of tubular bones in the pediatric population. Lesions have characteristic appearances of cortical hyperostosis and mixed lytic/sclerotic medullary appearances radiographically, with active osteitis and periostitis best seen with fluid-sensitive sequences on magnetic resonance imaging (MRI). There are reports of lesions resolving on follow-up radiographs and MRI scans, but no supporting images. In particular, although the marrow appearances and degree of osteitis have been shown to improve on MRI, complete resolution and remodeling back to normal has never been demonstrated. We present a case of a lesion that has completely healed and remodeled back to normal appearances on both radiographs and MRI, and consider this the standard for the often loosely used terms "normalization" and "resolution". We discuss the implications of this for our understanding of the natural history of CRMO, and how this adds weight to the condition being significantly under-diagnosed. It provides a "gold standard" to be aimed for when assessing treatments for CRMO, and the optimal outcomes that are possible. It also provides further insight into the potential of pediatric bone to recover and remodel when affected by inflammatory conditions.

Radiographic morphology of normal ring apophyses in the immature cervical spine.

BACKGROUND: The ring apophyses of the cervical spine have a variable appearance that changes with age. The times at which they appear and fuse at each level are not fixed. In this study, we aim to detail normal ranges of appearance of these ossification centers for each age group. MATERIALS AND METHODS: One hundred and eighty patients under the age of 21 attending the Royal Stoke University Hospital for cervical spine radiographs were retrospectively identified. The presence or absence of ring apophyses at each cervical level and whether these had undergone fusion was reported, as were the thickness, length, and craniocaudal and anteroposterior distance of the apophysis from the vertebral body. The angulation of the apophysis relative to the endplate was also noted. RESULTS: The youngest patient in which apophyses were seen was aged 3, but apophyses were otherwise rarely seen before the age of 6. All apophyses were present from age 14, and the superior apophyses fused by the age of 18, although unfused inferior apophyses were still seen in the 20-year age group. It was observed that apophyses were rarely separated from the vertebral body by greater than 1 mm in craniocaudal distance (1%) or 2.5 mm in anteroposterior distance (2.6%) and the anterior apophysis was angulated towards the endplate in only 1% of cases. CONCLUSIONS: We have detailed the range of normal appearances of the ring apophyses of the developing cervical spine. Cervical spine apophyseal injury is thought to be rare, but knowledge of normative morphological features should help in this diagnosis.

MRI of inflammatory spondyloarthropathy following traumatic cauda equina syndrome.

BACKGROUND CONTEXT: Spondyloarthropathy has been described radiographically in patients following paralysis from spinal cord trauma. Onset of these findings after cauda equina syndrome have not been reported previously. Furthermore, the magnetic resonance documentation of its early evolution has not been recorded. PURPOSE: We report a case of early-onset spondyloarthropathy shown by magnetic resonance imaging (MRI) in a patient with cauda equina syndrome due to bilateral sacral insufficiency fractures. STUDY DESIGN: Unique case study review, one case. METHODS: Review of the clinical case notes and imaging including initial and subsequent MR imaging. RESULTS: The initial MRI of the lumbosacral spine showed bilateral sacral insufficiency fractures with a kyphotic deformity. The vertebral bodies were normal on the initial computed tomography and MRI studies, which did not reveal pre-existing features of sacroiliitis. The second MRI performed 5 months later clearly showed spondylitis at multiple vertebral levels with partial resolution 18 months post injury. CONCLUSION: Spondyloarthropathy in patients with paralysis due to spinal cord injury is well documented in the English language literature, but until now this has not been demonstrated by MRI. It is a rare complication of traumatic cauda equina syndrome that commences soon after the traumatic event and can resolve spontaneously.

A new method for measurement of subcoracoid outlet and its relationship to rotator cuff pathology at MR arthrography.

OBJECTIVE: Orthopaedic surgical studies have shown that variations in the vertical distance between the tip of the coracoid process and the supra-glenoid tubercle alter the shape of the subcoracoid outlet. Our objective was to measure the vertical distance between the coracoid tip and the supra-glenoid tubercle (CTGT) on MR and to assess whether this showed better correlation with rotator cuff pathology compared with the axial coraco-humeral distance. MATERIALS AND METHODS: A retrospective review was performed of 100 consecutive shoulder MR arthrograms. Vertical distance between the coracoid tip and the supraglenoid tubercle was measured in the sagittal oblique plane. Separate assessment was then made of tendon pathology of the subscapularis, supraspinatus and long head of biceps tendons. Axial coraco-humeral distance was then measured. Correlation between tendon abnormalities and the two measurements was then made. RESULTS: Of the 100 cases, 42 had subscapularis tendon lesions, 21 had lesions of the long head of biceps and 53 had supraspinatus tendon lesions. Mean vertical distance from the coracoid tip to supraglenoid tubercle was greater in those with lesions of any of these tendons and was statistically significant for the supraspinatus group (P = 0.005). Reduced axial coraco-humeral distance was also seen in patients with tendinopathy, although with less statistically significant difference (p = 0.059). CONCLUSION: Our results support orthopaedic studies that have shown that the vertical distance between the coracoid tip and the supraglenoid tubercle increases the incidence and risk of rotator cuff disease by altering the shape of the subcoracoid outlet.

Adiposis dolorosa (Dercum's disease): MRI and ultrasound appearances.

AIM: To describe ultrasound and magnetic resonance imaging (MRI) features of adiposis dolorosa, Dercum's disease, and to evaluate the MRI features prospectively against a large number of MRI examinations. MATERIALS AND METHODS: Institutional review board approval for this study was obtained. The imaging features at MRI and ultrasound of 13 cases of adiposis dolorosa (nine female, four male; age range 32-72 years) were reviewed. MRI findings typical for adiposis dolorosa were proposed and prospectively evaluated on 6247 MRI examinations performed over a period of 8 months. RESULTS: Adiposis dolorosa demonstrates multiple, oblong, fatty lesions in the superficial subcutaneous fatty tissue. They are mostly <2 cm in long axis diameter. They demonstrate nodular ("blush-like") increased fluid signal at unenhanced MRI and are markedly hyperechoic at ultrasound. There is no contrast medium enhancement at MRI and no increased Doppler signal at ultrasound. Most lesions were clinically asymptomatic, some were painful/tender. There was no imaging evidence of oedema or inflammation. During prospective validation of these MRI features on 6247 MRI examinations, two cases with typical imaging features were encountered; both were diagnosed as adiposis dolorosa on clinical review. All cases of adiposis dolorosa showed these imaging findings. This results in a very low likelihood that a nodular, blush-like appearance of subcutaneous fat on MRI is not due to adiposis dolorosa. DISCUSSION: Adiposis dolorosa, Dercum's disease, should be suggested in the presence of multiple (many) small, oblong, fatty lesions in the subcutaneous fatty tissue in adult patients if they are hyperechoic on ultrasound imaging or blush-like at unenhanced MRI; typically a small number of these lesions are tender/painful. Imaging does not demonstrate inflammation or oedema in relation to these lesions. These MRI features should suggest the diagnosis and are likely to be pathognomonic. The radiologist is often the first to suggest the diagnosis based on the imaging features.

SAPHO: What radiologists should know.

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) is an umbrella acronym for inflammatory clinical conditions whose common denominator is aseptic osteoarticular involvement with characteristic skin lesions. It involves all ages, can involve any skeletal site, and has variable imaging appearances depending on the stage/age of the lesion and imaging method. It mimics important differentials including infection and neoplasia. Awareness of the imaging features, especially in the spine, facilitates early diagnosis, prevents repeated biopsies, and avoids unnecessary surgery, while initiating appropriate treatment.

Destructive discovertebral degenerative disease of the lumbar spine.

The uncommon variant of degenerative hip joint disease, termed rapidly progressive osteoarthritis, and highlighted by severe joint space loss and osteochondral disintegration, is well established. We present a similar unusual subset in the lumbar spine termed destructive discovertebral degenerative disease (DDDD) with radiological features of vertebral malalignment, severe disc resorption, and "bone sand" formation secondary to vertebral fragmentation. Co-existing metabolic bone disease is likely to promote the development of DDDD of the lumbar spine, which presents with back pain and sciatica due to nerve root compression by the "bone sand" in the epidural space. MRI and CT play a complimentary role in making the diagnosis.

Observations on the natural history of massive lumbar disc herniation.

We have treated 15 patients with massive lumbar disc herniations non-operatively. Repeat MR scanning after a mean 24 months (5 to 56) showed a dramatic resolution of the herniation in 14 patients. No patient developed a cauda equina syndrome. We suggest that this condition may be more benign than previously thought.

Successful treatment of refractory tibial nonunion using calcium sulphate and bone marrow stromal cell implantation.

Successful healing of a nine-year tibial nonunion resistant to six previous surgical procedures was achieved by tissue engineering. We used autologous bone marrow stromal cells (BMSCs) expanded to 5 x 10(6) cells after three weeks' tissue culture. Calcium sulphate (CaSO4) in pellet form was combined with these cells at operation. The nonunion was clinically and radiologically healed two months after implantation. This is the description of on healing of a long-standing tibial nonunion by tissue engineering. The successful combination of BMSCs and CaSO4 has not to our knowledge been reported in a clinical setting.

Subcutaneous and lung metastases from chondrosarcoma of the thumb.

We present a rare case of metacarpal chondrosarcoma with cutaneous metastases in the ipsilateral upper arm. Chondrosarcomas of the small bones of the hand rarely metastasise unlike chondrosarcomas elsewhere in the body. Excision/ray amputation rather than curettage may be preferable in the treatment of high-grade chondrosarcomas in the hand.

Demonstration of osteochondritis dissecans of the talus by coronal computed tomographic arthrography.

Ten cases of osteochondritis dissecans of the talus are reviewed. Coronal computed tomographic arthrography identified the precise location in each case and consistently revealed the extent of the lesion to be greater than that apparent on the plain radiographs. The talar cartilage over the lesion was shown to be thinned in four cases, deficient in two, and fissuring of the cartilage was demonstrated in four. Subarticular cysts were identified in all but two cases and contrast medium was shown to enter the cysts in two cases indicating a communication with the ankle joint. The aetiology and relevance of these findings to treatment are discussed.

The incidence and significance of fluid-fluid levels on computed tomography of osseous lesions.

The demonstration of a fluid-fluid level (FFL) within an osseous lesion on computed tomography (CT) has been reported as suggestive of an aneurysmal bone cyst (ABC) although FFLS have also been rarely found in association with other lesions. This study was conducted to determine the frequency of FFLS on CT in a group of ABCs and a series of patients presenting to a major tertiary referral centre for the treatment of bone tumours. An FFL was present on CT in 21 (84%) of the 25 ABCs and in 17 was multiple. FFLs are typical of the mid ("blow-out") or late phase of development of an ABC and not the incipient ("permeative") stage or where the internal architecture of the tumour has been disrupted by biopsy or previous surgery. In a 3-year period, 16 ABCs were found in 491 bone lesions referred to a bone tumour treatment centre. CT of the ABCs revealed FFLs in 14 (87.5%) cases. Within the same period, 728 CTs of these and other bone lesions were performed and FFLs were identified in two further cases: a massive telangiectatic osteosarcoma and a conventional osteosarcoma following chemotherapy. The diagnostic significance of an FFL on CT for ABC is: sensitivity = 87.5%, specificity = 99.7%, positive predictive value = 87.5%, negative predictive value = 99.7%, accuracy = 99.4%. An FFL within a bone lesion on CT remains strongly suggestive of an ABC although the radiologist should be wary of a rare telangiectatic osteosarcoma.

The patello-femoral joint--a critical appraisal of its geometric assessment utilizing conventional axial radiography and computed arthro-tomography.

In the quest for treatable causes of anterior knee pain, plain film skyline views of the patello-femoral joint are requested, often in 30 degrees, 60 degrees and 90 degrees of flexion, to assess the functional relationships of the joint. Patello-femoral malalignment predisposes to recurrent subluxation and dislocation, articular cartilage damage and premature degenerative change. The aim of this study is to evaluate critically, by comparative assessment, the information provided by skyline views and axial computed arthro-tomography (CTA). Measurements of the patello-femoral angle (assesses patellar tilt), the congruence angle (assesses patellar lateralization) and the trochlear depth were made on Merchant's skyline views and on axial CTA on each of 50 symptomatic knees. Results are presented in graphic form with visual examples indicating a poor correlation between the two imaging methods. We conclude that skyline views are inaccurate and unsuitable primarily because they cannot be obtained in less than 30 degrees of flexion. We suggest that skyline views have no role to play in screening for maltracking as even florid examples must be missed, and would strongly urge that no surgery be performed on their basis alone as this would result in inappropriate operations. Although computed tomography is the preferred mode of assessing patello-femoral geometry, difficulties are still encountered and the ways of circumventing them are discussed.

Short communication: a lateral will do?

Efforts to reduce the dose of diagnostic medical irradiation by applying selective criteria for radiographic examinations have been addressed by the Royal College of Radiologists in their Guidelines. Reduction of the number of views of an area has also been suggested by some authors. Deviating from one of the fundamentals of skeletal radiology which requires at least two views of any part of the skeleton may lead to misdiagnosis. This concept is considered in relation to the lumbar spine. Continued routine acquisition of at least two views for the radiographic examination of the lumbar spine is stressed.

Effect of Paget's disease of bone on areal lumbar spine bone mineral density measured by DXA, and density of cortical and trabecular bone measured by quantitative CT.

Although bone density may be increased in bone that is affected by Paget's disease, density changes in cortical and trabecular bone and the effect on bone that is apparently unaffected by Paget's disease are relatively unexplored. We have investigated 81 vertebrae (28 affected, 53 unaffected) in 27 patients with Paget's disease, by dual X-ray absorptiometry (DXA) and by quantitative CT (QCT) bone density measurements of trabecular and cortical bone. DXA bone density was high (mean z-score = 1.62, p < 0.001) in vertebrae affected by Paget's disease, but not significantly different from normal in unaffected vertebrae (mean z-score = 0.07, ns). Mean QCT z-score in Paget's vertebrae was 2.07 (p = 0.009) for cortical bone and 1.37 (p = 0.008) for trabecular bone. DXA correlated with QCT cortical values in affected and unaffected bone (r = 0.8 and 0.56, respectively), and with QCT trabecular values (r = 0.72 and 0.48, respectively). There was no significant difference in the slopes for the correlations in affected or unaffected bone. Cortical QCT values are underestimated in Paget's disease compared with physical measurements of density, owing to the computer algorithm used. High DXA values may alert to the possibility of Paget's disease, especially if the value deviates from the expected normal sequence in lumbar vertebrae. Osteoporotic vertebrae may be overlooked if the average value of bone mineral density is taken in the lumbar spine without reviewing each vertebra.

A comparison of a conventional non-ionic contrast medium (iohexol) alone and with adrenaline and an iso-osmolar non-ionic contrast medium (iotrolan) in computed tomographic arthrography of the shoulder.

The physico-chemical properties of the iso-osmolar dimeric contrast medium iotrolan offers potential advantages in computed tomographic arthrography (CTA). A trial was undertaken comparing iotrolan with iohexol to assess if these theoretical benefits produced an increase in the measured densities in a series of shoulder CTAs. The results showed that iotrolan did produce clinically useful increases in density when compared to a monomeric non-ionic contrast medium. The addition of adrenaline to the monomeric contrast medium produced a significant improvement in the computed tomography density which surpassed that offered by the dimeric contrast medium alone.

Spinal injury: optimising the imaging options.

There have been numerous documented attempts in formulating risk-based guidelines for the exclusion of spinal injury using conventional radiography. Although the advent of computed tomography (CT) (including spiral and multi-slice) and magnetic resonance imaging (MRI) confirmed the known limitations of conventional radiography, there is still a requirement to define optional use of these modalities in a trauma setting. This chapter addresses these issues by reviewing the literature and provides a synopsis of the current thinking in the appropriate sections (adult, paediatric, symptomatic, asymptomatic, etc.) in the quest of finding out the correct answers on how best to exclude/confirm spinal trauma.

MRI of the ageing and herniating intervertebral disc.

The role of diagnostic imaging from the patient's perspective is to provide answers to four basic questions:--what is wrong?, How bad is it?, Is it clinically relevant?, Can it be treated? In the assessment of spinal disorders, multiple modalities have evolved in an attempt to answer the questions poised. Without doubt, the advent of MRI has given this process significant benefits primarily because of the unparalleled way of depicting normal and abnormal tissues in a non-invasive manner. In particular, MRI is admirably suited to study the intervertebral disc and goes a long way in answering the first two questions, aiding in the accurate analysis of disc morphology, defining pathological states, and delineating the extent and effect of disease. This information however, needs to be equated with the clinical signs and symptoms before any decisions concerning treatment options can be made. At this point one needs to exercise some degree of prudence and remember that MRI as yet does not differentiate abnormal asymptomatic from symptomatic painful disc levels. Enhancement with gadolinium compounds may go some way in providing some answers by defining the tissue response at or around the damaged points within the disco-vertebral unit. Modern MRI scanners and techniques demonstrate exquisitely, the structural status of the disc but the functional impact of these structural alterations cannot as yet be fully determined by MRI--there lies the challenge for the future. This article reviews the current MRI knowledge concerning the ageing and herniating intervertebral disc in a clinical context, and critically appraises its present role in a practical fashion.

Provocation discography as a guide to planning operations on the spine.

In a prospective study we attempted to define the role of lumbar discography in the investigation of patients with low back pain with or without non-dermatomal pain in the lower limb. The records of 195 patients were studied at least two years after a technically successful operation. Of 137 patients in whom discography had revealed disc disease and provoked symptoms, 89% derived significant and sustained clinical benefit from operation. Of 25 patients whose discs showed morphological abnormality but had no provocation of symptoms on discography only 52% had clinical success. These findings support the continued use of lumbar discography for the investigation of this particular group of patients.

Intra-epiphyseal stress injury of the proximal tibial epiphysis: preliminary experience of magnetic resonance imaging findings.

Stress induced injuries affecting the physeal plate or cortical bone in children and adolescents, especially young athletes, have been well described. However, there are no reports in the current English language literature of stress injury affecting the incompletely ossified epiphyseal cartilage. We present four cases of stress related change to the proximal tibial epiphysis (PTE) along with their respective magnetic resonance imaging (MRI) appearances ranging from subtle oedema signal to a pseudo-tumour like appearance within the epiphyseal cartilage. The site and pattern of intra-epiphyseal injury is determined by the type of tissue that is affected, the maturity of the skeleton and the type of forces that are transmitted through the tissue. We demonstrate how an awareness of the morphological spectrum of MRI appearances in intra-epiphyseal stress injury and the ability to identify concomitant signs of stress in other nearby structures can help reduce misdiagnosis, avoid invasive diagnostic procedures like bone biopsy and reassure patients and their families.