Diffuse vertebral marrow changes at MRI: Multiple myeloma or normal?

Five MRI patterns of marrow involvement (diffuse, focal, combined diffuse and focal, variegated, and normal) are observed in patients with a marrow proliferative disorder including MM. The wide range of marrow involvement patterns in monoclonal plasma cell proliferative disorders mirrors that of their natural histories that can vary from indolent to rapidly lethal. MRI of the axial bone marrow contributes to stage these disorders, but it should not be obtained for disease detection and characterization because of its limited specificity and sensitivity. At MRI, diffuse benign hematopoietic marrow hyperplasia and marrow heterogeneities in elderly patients mimic the diffuse and variegated patterns observed in MM patients. Careful analysis of fat- and fluid-sensitive MR images and quantitative marrow assessment by using MRI and FDG-PET can contribute in differentiating these changes from those associated with neoplastic marrow infiltration, with some residual overlapping findings.

Aneurysmal bone cystic lesions: value of genomic studies.

Aneurysmal bone cystic (ABC) lesions can be primary or secondary (to a trauma or a pre-existing benign or malignant tumour). Specific translocations of the USP6 gene are reported in about 70% of primary but never in secondary ABC lesions. We report two cases of ABC lesions in which imbalanced genomic aberrations were detected at initial presentation and showed complex clonal evolution. These demonstrative observations strengthen the guidelines regarding the diagnostic approach when an ABC is suggested by imaging. Biopsy is mandatory including genomic analysis. When a primary ABC is not clearly proven by the initial biopsy, an extensive curettage should be performed, with pathological examination of all removed tissue in order to exclude a secondary ABC. It also illustrates the added value of genomic analyses in the setting of an ABC lesion: complex clonal aberrations argues for a lesion secondary to a malignant proliferation whereas USP6 rearrangement allows the diagnosis of primary ABC.

Unusual case of tetraparesis in a patient with systemic lupus erythematosus.

We describe the case of a 67-year-old Asian female patient suffering from severe systemic lupus erythematosus (SLE), including biopsy-proven glomerulonephritis, since the age of 40 who was admitted for tetraparesis. Neurological examination confirmed proximal muscular weakness, hypoesthesia and diminished tendon reflexes. The patient suffered from extremely severe Jaccoud's arthropathy. Magnetic resonance imaging (MRI) demonstrated severe narrowing of the upper spinal canal due to a soft tissue mass surrounding the odontoid process, assumed to be a synovial pannus, causing myelopathy. The patient was treated with three intravenous pulses of methylprednisolone with prompt and full clinical recovery. Follow-up MRI confirmed considerable regression of the pannus. Inflammatory transverse myelopathy is the most common explanation for para/tetraparesis in SLE. However, in this case, the symptoms were caused by atlantoaxial synovitis, which is more typical for rheumatoid arthritis.

Vertebral sarcoidosis: long-term follow-up with MRI.

Vertebral involvement in sarcoidosis is rare and its clinical and imaging features are non-specific. Indeed, because the lesions are hard to differentiate from metastatic disease based on imaging alone, a histological confirmation is advised. Fatty replacement is a well-known finding indicating stabilization and healing in both benign and malignant conditions. It can be used as an indicator of a favorable disease course and response to treatment. We report the case of a 43-year-old woman with multifocal vertebral sarcoidosis lesions and long-term follow-up showing progressive and gradual fatty involution on magnetic resonance imaging (MRI) during 4 years of steroid treatment with a final favorable outcome.

MRI for response assessment in metastatic bone disease.

BACKGROUND: Beyond lesion detection and characterisation, and disease staging, the quantification of the tumour load and assessment of response to treatment are daily expectations in oncology. METHODS: Bone lesions have been considered "non-measurable" for years as opposed to lesions involving soft tissues and "solid" organs like the lungs or liver, for which response evaluation criteria are used in every day practice. This is due to the lack of sensitivity, specificity and measurement capabilities of imaging techniques available for bone assessment, i.e. skeletal scintigraphy (SS), radiographs and computed tomography (CT). RESULTS: This paper reviews the possibilities and limitations of these techniques and highlights the possibilities of positron emission tomography (PET), but mainly concentrates on magnetic resonance imaging (MRI). CONCLUSION: Practical morphological and quantitative approaches are proposed to evaluate the treatment response of bone marrow lesions using "anatomical" MRI. Recent developments of MRI, i.e. dynamic contrast-enhanced (DCE) imaging and diffusion-weighted imaging (DWI), are also covered. KEY POINTS: • MRI offers improved evaluation of skeletal metastases and their response to treatment. • This new indication for MRI has wide potential impact on radiological practice. • MRI helps meet the expectations of the oncological community. • We emphasise the practical aspects, with didactic cases and illustrations.

[Comparison of lumbar spinal canal measurements on MRI and CT]. / Comparaison des mesures du canal lombaire en IRM et TDM.

PURPOSE: To compare AP diameter measurements of spinal canal and thecal sac on MRI and CT. MATERIALS AND METHODS: The AP diameter of the spinal canal at L4 and thecal sac at L4-5 were measured on both MRI and CT performed on patients at less than one month interval. Measurements were obtained from axial CT images of the abdomen on CT and sagittal T1W (n = 98) and T2W (n = 78) MR images of the spine. The examinations were reviewed at more than 24 hours interval. Radiologists were blinded. Inter-observer agreement evaluation was performed prior to this study. Measurements were compared using a t test for paired variables. RESULTS: For the spinal canal, mean measurements were 0.4 +/- 1.5mm inferior on CT compared to MRI. For the thecal sac, mean measurements were 0.1 +/- 1.4mm inferior on CT compared to MRI. CONCLUSION: Measurements on CT and MRI for lumbar spinal canal and thecal sac are fairly comparable, with mean measurement differences inferior to the degree of precision of the measurement technique itself.

MRI detection of radiographically occult fractures of the hip and pelvis in the elderly: Comparison of T2-weighted Dixon sequence with T1-weighted and STIR sequences.

PURPOSE: To compare the diagnostic performance of T2-weighted Dixon, T1-weighted and Short-Tau Inversion Recovery (STIR) MR images for the detection of radiographically occult fractures (ROF) of the hip and pelvis in elderly patients after low-energy trauma. MATERIALS AND METHODS: A total of 22 patients older than 50 years with suspected ROF after low-energy trauma was prospectively included. There were 9 men and 13 women, with a mean age of 80.9 years±12.5 (SD) (range: 52-100 years). T2-weighted Dixon, T1-weighted and STIR MR images were analyzed by 3 independent radiologists blinded to the clinical data and the results of other imaging examinations. Readers separately assessed each series of images for the presence of fractures on a per bone analysis. Diagnostic performance of each reader was compared for Dixon and non-Dixon sequences using contingency tables and McNemar test. Interobserver agreement was evaluated according to the Fleiss-Cuzick's kappa statistics. RESULTS: The sensitivity of the Dixon sequence in the detection of ROF ranged from 90.9% (20/22; 95% CI: 70.8-98.9%) to 100% (22/22; 95% CI: 84.6-100%). The sensitivities of the non-Dixon sequences in the detection of ROF ranged from 95.5% (21/22; 95% CI: 77.2-99.9%) to 100% (22/22; 95% CI: 84.6-100%). For each reader, there were no statistical differences between combined Dixon and combined non-Dixon images for the detection of ROF (P=0.12, 0.99 and 0.99). Interobserver agreement with T2-weighted Dixon water-only images was significantly lower than that with the STIR sequence (0.70-0.79 vs. 0.87-0.93). CONCLUSION: T2-weighted Dixon may be a second-rate alternative to T1-weighted and STIR sequences for the detection of ROF of the hip and pelvis in elderly patients.

[Plain radiography of the knee: the articular surfaces]. / Relecture des radiographies standard du genou: les surfaces articulaires.

Lateral knee radiographs allow recognition of both medial and lateral femoral and tibial surfaces, groove and anterior borders of the trochlea and lateral facet and ridge of the patella. Analysis of these lines allows detection of focal contour abnormalities, femoral trochlear dysplasia and patellar tilt. Qualitative radiological analysis of the osseous surfaces detects the particular aspect of abraded subchondral bone ("drawn with chalk"), preventing the trap of false joint spaces on non weight-bearing views. Occasionally, very subtle bone abnormalities can be recognized in cases of cartilaginous, subchondral or even meniscal lesions. However, these focal abnormalities are not constant, and their visualization is somewhat anecdotal.

Magnetic resonance imaging (MRI) of the knee: Identification of difficult-to-diagnose meniscal lesions.

This article characterizes common meniscal pathologies, reviews magnetic resonance imaging (MRI) diagnostic criteria for meniscal tears, and identifies difficult-to-detect tears and fragments and the best MRI sequences and practices for recognizing these lesions. These difficult-to-diagnose meniscal lesions that radiologists should consider include tears, meniscocapsular separation lesions, and displaced meniscal fragments. Meniscus tears are either vertical, which are generally associated with traumatic injury, horizontal, which are associated with degenerative injury, or combinations of both. MRI has a high sensitivity for tears but not for fragments; MRI performance is also better for medial than lateral meniscal lesions. Fragment detection can be improved by recognizing signs secondary to migration, especially signs of epiphyseal irritation and mechanical impingement. Radial and peripheral tears, as well as those close to the posterior horn insertion, have been traditionally difficult to detect, but improvements in arthroscopic knowledge, identification of common lesion patterns, and selection of the proper MRI sequence and plane for each lesion type mean that, when properly used, MRI is an invaluable tool in detecting all types of meniscal tears.

Imaging ACL reconstructions and their complications.

Examination of ligament reconstructions, particularly of the anterior cruciate ligament (ACL), are common situations in everyday knee imaging practice. Knowledge of normal appearances, the expected changes over time and the potential complications of these plasties are essential. MRI is the imaging method of choice. This article illustrates the main complications specific to this procedure: suboptimal positioning of the femoral or tibial tunnels, impingement between the graft and bony contours, rupture (partial or complete) of the plasty due to friction or injury, arthrofibrosis and particularly the "Cyclops" syndrome, fragmentation or migration of the fixation materials and a granulomatous reaction to biomaterials.

Eosinophilic fasciitis: typical abnormalities, variants and differential diagnosis of fasciae abnormalities using MR imaging.

Eosinophilic fasciitis is a rare condition. It is generally limited to the distal parts of the arms and legs. MRI is the ideal imaging modality for diagnosing and monitoring this condition. MRI findings typically evidence only fascial involvement but on a less regular basis signal abnormalities may be observed in neighboring muscle tissue and hypodermic fat. Differential diagnosis of eosinophilic fasciitis by MRI requires the exclusion of several other superficial and deep soft tissue disorders.

Diffusion-weighted MR imaging in musculoskeletal diseases: current concepts.

MR imaging is currently regarded as a pivotal technique for the assessment of a variety of musculoskeletal conditions. Diffusion-weighted MR imaging (DWI) is a relatively recent sequence that provides information on the degree of cellularity of lesions. Apparent diffusion coefficient (ADC) value provides information on the movement of water molecules outside the cells. The literature contains many studies that have evaluated the role of DWI in musculoskeletal diseases. However, to date they yielded conflicting results on the use and the diagnostic capabilities of DWI in the area of musculoskeletal diseases. However, many of them have showed that DWI is a useful technique for the evaluation of the extent of the disease in a subset of musculoskeletal cancers. In terms of tissue characterization, DWI may be an adjunct to the more conventional MR imaging techniques but should be interpreted along with the signal of the lesion as observed on conventional sequences, especially in musculoskeletal cancers. Regarding the monitoring of response to therapy in cancer or inflammatory disease, the use of ADC value may represent a more reliable additional tool but must be compared to the initial ADC value of the lesions along with the knowledge of the actual therapy.

Treatment of the vertebral crush fracture syndrome with enteric-coated sodium fluoride tablets and calcium supplements.

A cohort of 101 patients were treated with enteric-coated sodium fluoride tablets and calcium supplements. Vitamin D was also given in supra-physiologic doses in 70% of the cases. Lumbar bone mineral density (BMD), as measured by dual-photon absorptiometry, increased in a linear fashion up to four years, irrespective of the value of initial BMD and of the underlying condition, be it involutional osteoporosis (the vast majority), glucocorticoid osteoporosis, or even osteogenesis imperfecta. Estrogen replacement therapy (ERT) seemed to promote the fluoride-induced increase in lumbar BMD, as did the vitamin D supplements. Of these patients, 17% proved "resistant" to the therapy. There was no way of predicting who would be in this category. Compared with an age- and sex-matched control group, women showed significantly different behavior of their bone mass. In the control group, the losses were highly significant at the lumbar spine and at all three scanning sites of the forearm, as measured by single-photon absorptiometry. In contrast, the fluoride group had a significant gain of BMD at the lumbar spine and changes of BMC at the forearm were not significant. Fluoride thus preserved bone mass at the appendicular skeleton, while increasing it at the axial skeleton. When comparing the patients who received vitamin D supplements and those who did not, there was a significant difference in the appendicular skeleton. The distal forearm in the vitamin D-supplemented group tended to gain, whereas the midforearm lost significant bone mass. The trend was reversed in the group without vitamin D-supplementation, a more favorable pattern. Therefore, vitamin D supplements should not, as a rule, be provided to such patients. The biochemical hallmark of the fluoride-induced changes is a slight rise of the alkaline phosphatase within the normal range. Alkaline phosphatase levels that exceed the upper limit of normal signal a warning that too much fluoride and/or too little calcium supplements are being administered, or that a fluoride-related complication is impending or has occurred (e.g., a stress fracture). Osteosclerosis was achieved in 69% of the cases who had a radiological followup of at least four years (average period of appearance: 1.8 years). Stress fractures in the lower limbs occurred in 17 patients, almost exclusively in females, and appeared on average 2.2 years after initiation of therapy. In this group of stress fractures there was significant cortical bone loss at midforearm.(ABSTRACT TRUNCATED AT 400 WORDS)

Biological and radiological responses to oral etidronate and tiludronate in Paget's disease of bone.

Paget's disease of bone is characterized by a high bone turnover. Therefore, antiresorbing agents such as bisphosphonates are clearly indicated. However, as they accumulate in the pagetic lesions, they could produce some focal defects of bone mineralization. In a double-blind study, we have had the opportunity to compare the effects of tiludronate and of etidronate (both at a fixed dose of 400 mg/day orally) on the radiological changes of 12 patients suffering from Paget's disease of bone. After breaking the code, good agreement was observed between the radiological evaluations and the applied therapy: All positive bone balances were observed in the tiludronate group, except for three questionable densifications in the etidronate group, and the negative bone balances in the etidronate group. This confirms our previous experience with etidronate in Paget's disease when X-ray films of the lesions are followed sequentially during therapy.

Ultrasonography of joint capsules and tendons in dialysis-related amyloidosis.

Beta-2-microglobulin (beta 2m) amyloid infiltrates joint synovia, tendons and capsules. We report a cross-sectional ultrasonographic (US) evaluation of supraspinatus tendons' (SST) and femoral neck capsules' (FNC) thickness in 49 patients on long-term hemodialysis. Normal values for SST and FNC were defined in control subjects. Among the 49 patients, aged 21 to 86 (median 59) years at the time of US, dialyzed for 1 to 228 (median 97) months, 33 had at least one abnormal joint. The prevalence of patients with at least one or at least two abnormal joints, the number of abnormal joints per patient and the thickness of SST and FNC increased significantly with dialysis duration (P < 0.001 for all parameters considered). All (N = 11) patients with radiological and/or histological evidence of dialysis-related amyloidosis (DRA) had thickened SST and/or FNC. Twenty-two other patients without similar evidence of DRA also had thickened FNC and/or SST. Three died; post-mortem examination demonstrated that US abnormalities were due to beta 2m amyloid infiltration. We suggest that SST and FNC thickness, measured by US, is a useful, non-invasive tool for the diagnosis of DRA.

Gout in the cervical spine: MR pattern mimicking diskovertebral infection.

We report the MR features of a surgically proved cervical spine involved with gouty tophi in a patient with a long history of hyperuricemia. Tophi appeared as sharply delineated areas of low signal intensity on T1 and T2 MR images and showed intense and homogeneous signal enhancement on post-contrast images.

The lumbar vertebral body and diskovertebral junction. Radio MR imaging anatomic correlations.

Radiographs and MR images of spine specimens provide superb tomographic views of changes that involve the mineralized network and the medullary content of vertebral bodies. By illustrating changes in the balance between bone resorption and formation and between fat and nonfat marrow cells, these frozen images of the reality help us to understand normal variants and lesions that develop in osseous and articular diseases of the lumbar spine.

Pustulotic arthro-osteitis in children and adults. A report of 13 cases.

Thirteen cases of pustulotic arthro-osteitis are reported: 3 children and 10 adults. The clinical and radiological aspects of this rare entity are discussed as well as the classification of this disease in the context of seronegative spondyloarthropathies.

Effect of renal transplantation on the radiological signs of dialysis amyloid osteoarthropathy.

We have assessed the fate of amyloid bone cysts after a successful renal transplantation in 5 patients who had been on dialysis for 7 to 15 years. The size of 34 cysts, typical of amyloid osteoarthropathy, was monitored on annual X-rays for 29 to 75 (mean 47) months after TP. In sharp contrast to their progression during dialysis, cysts did not increase in size and no new cysts appeared during follow-up. However, despite a successful graft, none of the 34 cysts regressed significantly. The stability of the bone cysts may reflect either the poor solubility of the beta 2-m amyloid deposits or the limited accessibility of bone deposits to lytic factors. A longer follow-up will perhaps be necessary to document a significant regression of the cysts. Strikingly, transplantation resulted within a few days in an almost complete relief of articular complaints; in the absence of evidence of amyloid regression, this probably reflects the anti-inflammatory effect of steroids.

Transient cyst-like cortical defects following fractures in children. Medullary fat within the subperiosteal haematoma.

Asymptomatic cyst-like cortical defects appearing after fractures in children have been occasionally reported. Typically, these defects appear during fracture consolidation, within the newly formed subperiosteal bone, proximal to the fracture line, do not enlarge, and progressively disappear. We have previously shown a fatty density on CT scan within the early cortical defect. We now present two additional cases in which early CT scans appeared to confirm that these transient cortical defects may consist of fat, and probably result from the inclusion of medullary fat within the subperiosteal haematoma.