Diagnostic accuracy of lumbar CT and MRI in the evaluation of chronic low back pain without red flag symptoms.

BACKGROUND: Low back pain (LBP) is one of the most frequent reasons for medical consultation. Most of the patients will have nonspecific LBP, which usually are self-limited episodes. It is unclear which of the diagnostic imaging pathways is most effective and costeffective and how the imaging impacts on patient treatment. Imaging techniques are usually indicated if symptoms remain after 6 weeks. Magnetic resonance imaging (MRI) is the diagnostic imaging examination of choice in lumbar spine evaluation of low back pain; however, availability of MRI is limited. OBJECTIVES: To evaluate the diagnostic accuracy of computed tomography (CT) with MRI (as standard of reference) in the evaluation of chronic low back pain (LBP) without red flags symptoms. To compare the results obtained by two radiologists with different grades of experience. MATERIALS AND METHODS: Patients with chronic low back pain without red flags symptoms were retrospectively reviewed by two observers with different level of experience. Patients included had undergone a lumbar or abdominal CT and an MRI within a year. Once the radiological information was collected, it was then statistically reviewed. The aim of the statistical analysis is to identify the equivalence between both diagnostic techniques. To this end, sensitivity, specificity and validity index were calculated. In addition, intra and inter-observer reliability were measured by Cohen's kappa values and also using the McNemar test. RESULTS: 340 lumbar levels were evaluated from 68 adult patients with chronic low back pain or sciatica. 63.2% of them were women, with an average age of 60.3 years (SD 14.7). CT shows high values of sensitivity and specificity (>80%) in most of the items evaluated, but sensitivity was low for the evaluation of density of the disc (40%) and for the detection of disc herniation (55%). Moreover, agreement between MRI and CT in most of these items was substantial or almost perfect (Cohen's kappa-coefficient > 0'8), excluding Modic changes (kappa = 0.497), degenerative changes (kappa0.688), signal of the disc (kappa = 0.327) and disc herniation (kappa = 0.639). Finally, agreement between both observers is mostly high (kappa > 0.8). Foraminal stenosis, canal stenosis and the grade of the canal stenosis were overdiagnosed by the inexperienced observer in the evaluation of CT images. CONCLUSIONS AND SIGNIFICANCE: CT is as sensitive as lumbar MRI in the evaluation of most of the items analysed, excluding Modic changes, degenerative changes, signal of the disc and disc herniation. In addition, these results are obtained regardless the experience of the radiologist. The rising use of diagnostic medical imaging and the improvement of image quality brings the opportunity of making a second look of abdominal CT in search of causes of LBP. Thereby, inappropriate medical imaging could be avoided (2). In addition, it would allow to reduce MRI waiting list and prioritize other patients with more severe pathology than LBP.

Percutaneous management of bone metastases: State of the art.

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty/vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600 Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900 MHz-2450 MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65 °C-85 °C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

Morel-Lavallée lesion: diagnosis and treatment with imaging techniques. / Lesión de Morel-Lavallée: diagnóstico y tratamiento con técnicas de imagen.

OBJECTIVES: We aim to review the characteristics of Morel-Lavallée lesions and to evaluate their treatment. MATERIAL AND METHODS: We retrospectively reviewed 17 patients (11 men and 6 women; mean age, 56.1 years, range 25-81 years) diagnosed with Morel-Lavallée lesions in two different departments. All patients underwent ultrasonography, 5 underwent computed tomography, and 9 underwent magnetic resonance imaging. Percutaneous treatment with fine-needle aspiration and/or drainage with a 6F-8F catheter was performed in 13 patients. Two patients required percutaneous sclerosis with doxycycline. RESULTS: All patients responded adequately to percutaneous treatment, although it was necessary to repeat the procedure in 4 patients. CONCLUSIONS: Radiologists need to be familiar with this lesion that can be treated percutaneously in the ultrasonography suite when it is not associated with other entities.

Musculoskeletal interventional radiology: ultrasound and CT. / Intervencionismo en musculoesquelético. Ecografía y tac.

We aim to describe imaging-guided (ultrasound and CT) interventional techniques in the musculoskeletal system that can be performed by general radiologists, whether in hospitals, primary care clinics, private offices, or other settings. The first requirement for doing these procedures is adequate knowledge of the anatomy of the musculoskeletal system. The second requirement is to inform the patient thoroughly about the technique, the risks involved, and the alternatives available in order to obtain written informed consent. The third requirement is to ensure that the procedure is performed in accordance with the principles of asepsis in relation to the puncture zone and to all the material employed throughout the procedure. The main procedures that can be done under ultrasound guidance are the following: fine needle aspiration cytology (FNAC), core needle biopsy (CNB), diagnostic and/or therapeutic arthrocentesis, drainage of juxta-articular fluid collections, drainage of abscesses, drainage of hematomas, treatment of Baker's cyst, treatment of ganglia, treatment of bursitis, infiltrations and treatment of plantar fasciitis, plantar fibrosis, epicondylitis, Achilles tendinopathy, and Morton's neuroma, puncture and lavage of calcifications in calcifying tendinopathy. We also review the following CT-guided procedures: diagnosis of spondylodiscitis, FNAC of metastases, arthrography, drainages. Finally, we also mention more complex procedures that can only be done in appropriate settings: bone biopsies, treatment of facet joint pain, radiofrequency treatment.

Guidelines for magnetic resonance imaging in axial spondyloarthritis: A Delphi study.

OBJECTIVE: The term axial spondyloarthritis refers to a group of chronic inflammatory rheumatic diseases with a common genetic basis that course with axial and peripheral involvement and enthesitis. Recently, the Assessment of SpondyloArthritis international Society (ASAS) established some diagnostic criteria, including for the first time magnetic resonance imaging (MRI) findings. Given the difficulties of obtaining MRI in some environments and the lack of experience with axial spondyloarthritis, a group of radiologists and rheumatologists sought to establish some practical guidelines to ensure the correct use of MRI in this disease. MATERIAL AND METHODS: Using the Delphi method, we used a questionnaire with 49 items stratified into 4 blocks to survey 46 experts in the MRI diagnosis of axial spondyloarthritis. RESULTS: The experts agreed on 82% of the items. The degree of agreement was 100% in the block "Importance of early diagnosis of axial spondyloarthritis", 69% in the block "Optimization of the use of MRI in the diagnosis of axial spondyloarthritis", 93% in the block "Use of MRI in axial spondyloarthritis: Technical aspects", and 57% in the block "Usefulness of MRI in the prognosis, follow-up, and evaluation of the response to treatment in axial spondyloarthritis". CONCLUSIONS: Despite the importance of MRI in the early diagnosis of axial spondyloarthritis, this study shows the need for standardization and points to relative disagreement about how to use MRI in the follow-up of the disease and evaluation of the response to treatment. The results of this study can help improve the use of MRI in axial spondyloarthritis.

Accuracy of magnetic resonance imaging in differentiating between benign and malignant vertebral lesions: role of diffusion-weighted imaging, in-phase/opposed-phase imaging and apparent diffusion coefficient.

OBJECTIVE: To determine the ability of MRI to distinguish between benign and malignant vertebral lesions. MATERIAL AND METHODS: We included 85 patients and studied a total of 213 vertebrae (both pathologic and normal). For each vertebra, we determined whether the lesion was hypointense in T1-weighted sequences and whether it was hyperintense in STIR and in diffusion-weighted sequences. We calculated the in-phase/out-of-phase quotient and the apparent diffusion coefficient for each vertebra. We combined parameters from T1-weighted, diffusion-weighted, and STIR sequences to devise a formula to distinguish benign from malignant lesions. RESULTS: The group comprised 60 (70.6%) women and 25 (29.4%) men with a mean age of 67±13.5 years (range, 33-90 y). Of the 85 patients, 26 (30.6%) had a known primary tumor. When the lesion was hypointense on T1-weighted sequences, hyperintense on STIR and diffusion-weighted sequences, and had a signal intensity quotient greater than 0.8, the sensitivity was 97.2%, the specificity was 90%, and the diagnostic accuracy was 91.2%. If the patient had a known primary tumor, these values increased to 97.2%, 99.4%, and 99%, respectively. CONCLUSION: Benign lesions can be distinguished from malignant lesions if we combine the information from T1-weighted, STIR, and diffusion-weighted sequences together with the in-phase/out-of-phase quotient of the lesion detected in the vertebral body on MRI.

[Imaging-guided percutaneous biopsy of tumors of the locomotor apparatus]. / Biopsia percutánea guiada por técnicas de imagen en patología tumoral del aparato locomotor.

The prognosis of musculoskeletal sarcomas is related to appropriate management by specifically trained multidisciplinary teams. Musculoskeletal radiologists are responsible for the image-guided percutaneous biopsy of these tumors, which has a diagnostic accuracy of at least 80%. It is essential for radiologists to know: a) the limitations of percutaneous biopsy with respect to surgical biopsy; b) what should and should not be biopsied; c) how to appropriately plan percutaneous biopsy, with special attention to the route of approach, taking into account the compartmental anatomy and the route of approach after surgical treatment; and d) technical aspects of the procedure, like the area of the tumor to biopsy, the caliber of the needle, the number and length of the specimens to obtain to ensure optimal pathological diagnosis, and techniques in function of the imaging modality and bone penetration.

[Percutaneous radiofrequency ablation of benign bone tumors: osteoid osteoma, osteoblastoma, and chondroblastoma]. / Tratamiento mediante radiofrecuencia percutánea de los tumores óseos benignos: osteoma osteoide, osteoblastoma y condroblastoma.

We report our experience in the computed tomography (CT)-guided percutaneous radiofrequency ablation of more than 100 benign bone tumors in the last eight years. We affirm that this should be the technique of choice in the vast majority of osteoid osteomas; it can also be applied as a definitive treatment in many cases of osteoblastomas or chondroblastomas as well as in less common benign bone tumors. CT-guided percutaneous radiofrequency ablation has proven highly efficacious and has resulted in very few complications; thus, patients tend to recover very quickly.

[Carpal tunnel syndrome in childhood.]. / Síndrome del túnel carpiano en la infancia.

Introduction. Carpal tunnel syndrome (CTS) has usually a different clinical presentation in children compared to adults. On top of this, its rarity in childhood makes it difficult to diagnose. It has also different etiologies at this age, the majority of cases occur in children with lysosomal storage diseases (mucopolysaccharidosis and mucolipidosis) which may be the first manifestation of this disease in some cases. Clinical case. In this article we describe 3 cases of children aged between 4 and 10 years, 2 with idiopathic CTS and 1 with primary familial origin. The symptoms of the former were intermittent paresthesias and handling difficulty, while the familial case presented with a more typical paresthesias and pain. The neurophysiological study confirmed the diagnosis. Concerning the patient with a history of CTS in the family, MRI showed a compression of the nerve due to the thickening of the flexor retinaculum. In all cases, lysosomal storage disease was ruled out and a conservative treatment was initiated. Evolution was favorable in the idiopathic cases, one of them with an almost complete remission of symptoms, while the patient with a familial CTS follows a progressive course and is waiting for the surgical assessment. Discussion. The CTS in pediatric age presents milder and more unspecific symptoms than in adults, and the results of the exploration and provocation tests are often unclear. Surgical treatment is almost always necessary, although some idiopathic cases, particularly if they are not associated to the thickening of the flexor retinaculum, may improve with a conservative treatment.

[Radiological characteristics of malignant fibrous histiocytoma of bone]. / Características radiológicas del fibrohistiocitoma maligno del hueso.

Malignant fibrous histiocytoma (MFH) was only recognized as a primary bone tumor a few years ago. Although it is much rarer than malignant fibrous histiocytoma of soft tissues, it is not extremely uncommon. It predominantly affects long bones; however, it has been reported to occur in many different sites and at any age. MFH are aggressive tumors that can appear in association with other bone lesions, and they have a poor prognosis. We present our experience with 13 cases of MFH and review the literature to describe the main characteristics of this tumor.