RESUMO
The introduction of new ultrashort and zero echo time (ZTE) sequences is revolutionizing magnetic resonance imaging (MRI) and optimizing patient management. These sequences acquire signals in tissues with very short T2: mineralized bone, cortical bone, and calcium deposits. They can be added to a classic MRI protocol. ZTE MRI provides computed tomography-like contrast for bone.
Assuntos
Osso e Ossos , Imageamento por Ressonância Magnética , Humanos , Osso e Ossos/diagnóstico por imagem , Osso Cortical , Tomografia Computadorizada por Raios X , Espectroscopia de Ressonância MagnéticaRESUMO
OBJECTIVE: The purpose of this study is to evaluate stereoradiographic measurements of femoral torsion with different femoral positions, in comparison with CT measurements, with use of the current standard axial-slice technique. We hypothesize that CT measurements vary with femoral spatial positioning because of the resulting projection onto the CT plane, whereas stereoradiographic measurements, which are derived from a 3D reconstruction of the femur, remain constant. MATERIALS AND METHODS: Both in vitro and in vivo studies were conducted. CT and stereoradiographic examinations were performed using 30 dry femurs in the following six femoral positions: neutral position (with the femoral mechanical axis aligned with the longitudinal axis of the CT scanner or stereoradiography system), 10° of abduction, 10° of adduction, 5° of flexion, 10° of flexion, and 5° of extension. The impact of femoral position on torsion measurement was assessed using paired t tests. In addition, 18 patients (mean [± SD] age, 42.3 ± 19.9 years) who underwent both CT and stereoradiography examinations were retrospectively assessed. The correlation between femoral positioning and torsion measurement was determined using the Pearson correlation coefficient. RESULTS: Flexion and extension statistically significantly affected CT measurement of femoral torsion (p < 0.01) but not stereoradiography measurement (p > 0.21). A strong correlation existed between hip flexion and the difference between femoral torsion measured by CT and stereoradiography (r = -0.80). CONCLUSION: The accuracy of femoral torsion determined by axial CT depends on the position of the femur. Hip flexion significantly reduced the femoral torsion angle measured by CT. Conversely, the accuracy of stereoradiography was independent of femur positioning. Thus, stereoradiography is preferable to CT for accurate measurement of femoral torsion, while it also substantially reduces the radiation dose.
Assuntos
Fêmur/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Anormalidade Torcional/diagnóstico por imagem , Adolescente , Adulto , Idoso , Cadáver , Feminino , Fêmur/fisiopatologia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/fisiopatologia , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Posicionamento do Paciente , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Amplitude de Movimento Articular , Estudos Retrospectivos , Software , Anormalidade Torcional/fisiopatologia , Torção MecânicaRESUMO
Dixon techniques are part of the methods used to suppress the signal of fat in MRI. They present many advantages compared with other fat suppression techniques including (1) the robustness of fat signal suppression, (2) the possibility to combine these techniques with all types of sequences (gradient echo, spin echo) and different weightings (T1-, T2-, proton density-, intermediate-weighted sequences), and (3) the availability of images both with and without fat suppression from one single acquisition. These advantages have opened many applications in musculoskeletal imaging. We first review the technical aspects of Dixon techniques including their advantages and disadvantages. We then illustrate their applications for the imaging of different body parts, as well as for tumors, neuromuscular disorders, and the imaging of metallic hardware.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Doenças Musculoesqueléticas/patologia , HumanosRESUMO
PURPOSE: To establish a new imaging technique using dynamic MRI three-dimensional (3D) volumetric acquisition in real-time, on six normal shoulders for the analysis of the 3D shoulder kinematics during continuous motion. MATERIALS AND METHODS: At first, a standard static acquisition was performed. Then, fast images were obtained with a multi-slice 3D balanced gradient echo sequence to get a real time series during the initial phase of shoulder abduction. Subsequently, the images were reconstructed; registered and the translational patterns of the humeral head relative to the glenoid and the size of the subacromial space were calculated. Additionally, the intraobserver reproducibility was tested. RESULTS: The maximal abduction was on average 43° (30° to 60°) and the mean width of the subacromial space was 7.7 mm (SD: ±1.2 mm). Difference between extreme values and average values was low, respectively 2.5 mm on X-axis, 2 mm on Y-axis, 1.4 mm for the width of the subacromial space and 1.2° for the measure of the glenohumeral abduction. CONCLUSION: This study reported a dynamic MRI protocol for the monitoring of shoulder 3D kinematics during continuous movement. The results suggest that there is no superior shift of the humeral head during the first phase of abduction.
Assuntos
Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Amplitude de Movimento Articular/fisiologia , Articulação do Ombro/anatomia & histologia , Fenômenos Biomecânicos , Voluntários Saudáveis , Humanos , Projetos Piloto , Estudos Prospectivos , Articulação do Ombro/fisiologiaRESUMO
INTRODUCTION: Ulnar nerve lesions at the wrist (UNLW) are always difficult to localize clinically and sometimes electrophysiologically. Finding conduction block when studying ulnar motor nerve conduction (CB) across the wrist is sometimes the only way to demonstrate that the ulnar deep motor branch (UDMB) is entrapped. METHODS: An elderly woman who had bilateral carpal tunnel syndrome (CTS) and thumb osteoarthritis for many years experienced worsening of left hand impairment recently. RESULTS: Electrodiagnostic and ultrasound examinations revealed an acute and severe UDMB lesion related to pisotriquetral joint effusion. The patient received a local injection of a corticosteroid that provided rapid recovery. CONCLUSIONS: The diagnosis of UDMB lesion is especially difficult when CTS coexists, but CTS may allow for early diagnosis, if CB at the wrist is not overlooked. Chondrocalcinosis was responsible for the systemic inflammation, the CTS, the pisotriquetral joint effusion, and the UDBM compression, which has not been reported previously.
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Condrocalcinose/complicações , Síndromes de Compressão do Nervo Ulnar/diagnóstico , Idoso de 80 Anos ou mais , Articulações do Carpo , Síndrome do Túnel Carpal/etiologia , Eletromiografia , Feminino , Humanos , Condução Nervosa , Pisciforme , Piramidal , Síndromes de Compressão do Nervo Ulnar/etiologia , Síndromes de Compressão do Nervo Ulnar/fisiopatologiaRESUMO
Nowadays, conventional or digitalized teleradiography remains the most commonly used tool for the study of the sagittal balance, sometimes with secondary digitalization. The irradiation given by this technique is important and the photographic results are often poor. Some radiographic tables allow the realization of digitalized spinal radiographs by simultaneous translation of X-ray tube and receptor. EOS system is a new, very low dose system which gives good quality images, permits a simultaneous acquisition of upright frontal and sagittal views, is able to cover in the same time the spine and the lower limbs and study the axial plane on 3D envelope reconstructions. In the future, this low dose system should take a great place in the study of the pelvispinal balance. On the lateral view, several pelvic (incidence, pelvic tilt, sacral slope) and spinal (lumbar lordosis, thoracic kyphosis, Th9 sagittal offset, C7 plumb line) parameters are drawn to define the pelvispinal balance. All are interdependent. Pelvic incidence is an individual anatomic characteristic that corresponds to the "thickness" of the pelvis and governs the spinal balance. Pelvis and spine, in a harmonious whole, can be compared to an accordion, more or less compressed or stretched.
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Imageamento Tridimensional/métodos , Pelve/diagnóstico por imagem , Equilíbrio Postural/fisiologia , Coluna Vertebral/diagnóstico por imagem , Telerradiologia/métodos , Relação Dose-Resposta à Radiação , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/normas , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/normas , Pelve/fisiologia , Pelve/fisiopatologia , Radiografia , Coluna Vertebral/fisiologia , Coluna Vertebral/fisiopatologia , Telerradiologia/instrumentação , Telerradiologia/normasRESUMO
More than 222 000 hip and knee prostheses are implanted each year in France and this number is growing. Simple radiography is generally used to examine these prostheses in situ but this method has several limitations, including superimposition, the inability to visualize some parts of the prosthesis and to study them in the axial plane, and poor visualization of intra- and peri-articular soft tissues. This article describes the advantages offered by computed tomography and ultrasonography in this setting
Assuntos
Articulação do Quadril/diagnóstico por imagem , Prótese de Quadril , Articulação do Joelho/diagnóstico por imagem , Prótese do Joelho , Humanos , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
PURPOSE: The purpose of this study was to assess and compare the prevalence of meniscal, ligament and cartilage lesions on knee MRI in a series of age- and sex-matched patients with and without medial meniscal ossicle. MATERIALS AND METHODS: Forty-two knee MRI examinations obtained in 42 patients (36 men, 6 women; mean age, 42.5±22.2 [SD] years; range: 19-65years) on which a medial meniscal ossicle was present were compared to 42 knee MRI examinations obtained in 42 age- and sex-matched patients (36 men, 6 women; mean age, 41.8±20.6 [SD] years; range: 19-65years) on which no medial meniscal ossicles were present. Two radiologists (R1, R2) blinded to the presence of meniscal ossicle by reading only the fat-saturated intermediate-weighted MR images separately assessed the presence of meniscal, ligament and cartilage lesions on these 84 knee MRI examinations. Prevalence of meniscal and ligament lesions and degree of cartilage degradation at MRI were compared between knees with and those without medial meniscal ossicle. RESULTS: In knees with medial meniscal ossicle, R1 and R2 detected 33 (79%) and 38 (90%) medial meniscal lesions, respectively that involved the posterior root (n=25/32 for R1/R2), the posterior horn (n=19/14 for R1/R2) or the body (n=8/10 for R1/R2). The prevalence of posterior root tear (60% [25/42]/76% [32/42] for R1/R2) and that of anterior cruciate ligament (ACL) lesions (48% [20/42]/57% [24/42] for R1/R2) as well as the medial cartilage degradation score (3.35±0.87 [SD] for R1 and 3.92±0.78 [SD] for R2) were significantly greater in knees with than in knees without medial meniscal ossicle (root lesions: P<0.01 for both readers; ACL lesions and medial cartilage score: P<0.01 for both readers). CONCLUSION: On MRI examination, knees with a medial meniscal ossicle demonstrate a greater frequency of medial posterior root tear and of ACL lesions and a greater degree of medial femoro-tibial cartilage degradation by comparison with knees without medial ossicle.
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Lesões do Ligamento Cruzado Anterior , Lesões do Menisco Tibial , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Articulação do Joelho , Imageamento por Ressonância Magnética , Masculino , Meniscos Tibiais/diagnóstico por imagem , Pessoa de Meia-Idade , Adulto JovemRESUMO
Foot and ankle problems are frequent, daily pathologies. Nowadays, imaging is able to put in evidence the most part of these affections, in a simple, non traumatic way. A good clinical examination is of highest importance to guide the imaging technique. Well done simple X-rays in a standing position is the first mandatory step. Ultrasonography has revolutionized the study of the smooth parts of the foot: tendons, sprains, pathologies of plantar aponeurosis, hind-foot problems....It is therefore the first exam to ask for. Ultrasonography is enough to resolve a very important part of the superficial soft tissues pathologies. When this technique fails, whatever the reason, RMI is the best way to study soft tissues and bone marrow (stress fractures, small intraosseous lesions, osteonecrosis...). CTscan remains the best tool to study the hard part of the skeleton. Neither CTscan nor RMI can directly put in evidence the joint's cartilage with a high degree of precision. So, an arthrography remains mandatory to have a good study of the cartilage of the ankle.
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Diagnóstico por Imagem , Doenças do Pé/diagnóstico , Pé/patologia , HumanosRESUMO
BACKGROUND: The global range of motion of the arm is the result of a coordinated motion of the shoulder complex including glenohumeral (GH), scapulothoracic, sternoclavicular and acromioclavicular joints. METHODS: This study is a non-systematic review of kinematic patterns in degenerated shoulders. It is a based on our own research on the kinematics of the shoulder complex and clinical experience. RESULTS: For patients with subacromial impingement syndrome without rotator-cuff tears, most kinematic studies showed a small superior humeral translation relative to the glenoid and decreased scapular lateral rotation and posterior tilt. These scapular kinematic modifications could decrease the subacromial space and favor rotator-cuff tendon injury. For patients with shoulder pain and restricted mobility, the studies showed a significant increase in scapular lateral rotation generally seen as a compensation mechanism of GH decreased range of motion. For patients with multidirectional GH instability, the studies found an antero-inferior decentering of the humeral head, decreased scapular lateral rotation and increased scapular internal rotation. CONCLUSION: The clinical or instrumented assessment of the shoulder complex with a degenerative pathology must include the analysis of scapula-clavicle and trunk movements complementing the GH assessment. Depending on the individual clinical case, scapular dyskinesis could be the cause or the consequence of the shoulder degenerative pathology. For most degenerative shoulder pathologies, the rehabilitation program should take into account the whole shoulder complex and include first a scapular and trunk postural-correcting strategy, then scapulothoracic muscle rehabilitation (especially serratus anterior and trapezius inferior and medium parts) and finally neuromotor techniques to recover appropriate upper-limb kinematic schemas for daily and/or sports activities.
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Amplitude de Movimento Articular , Rotação , Escápula/fisiologia , Dor de Ombro/fisiopatologia , Fenômenos Biomecânicos , Humanos , Escápula/fisiopatologia , Ombro/fisiologia , Ombro/fisiopatologia , Síndrome de Colisão do OmbroRESUMO
BACKGROUND: MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases. METHODS: Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI. RESULTS: The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear) and without tears (tendinopathy) (p = 0.012). The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm) than in normals (3.4mm) (p = 0.02). The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm) and supraspinatus tear (9.3 mm) shoulders compared to normals (3.5mm) and tendinopathy (4.8mm) shoulders (p = 0.05). CONCLUSION: The Dynamic MRI enabled a novel measure; 'Looseness', i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.
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Cabeça do Úmero/diagnóstico por imagem , Lesões do Manguito Rotador/diagnóstico por imagem , Manguito Rotador/diagnóstico por imagem , Escápula/diagnóstico por imagem , Articulação do Ombro/diagnóstico por imagem , Tendinopatia/diagnóstico por imagem , Adulto , Idoso , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Cabeça do Úmero/patologia , Cabeça do Úmero/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Movimento , Estudos Prospectivos , Amplitude de Movimento Articular , Manguito Rotador/patologia , Manguito Rotador/fisiopatologia , Lesões do Manguito Rotador/patologia , Lesões do Manguito Rotador/fisiopatologia , Escápula/patologia , Escápula/fisiopatologia , Articulação do Ombro/patologia , Articulação do Ombro/fisiopatologia , Tendinopatia/patologia , Tendinopatia/fisiopatologiaRESUMO
Dyskinesia of the scapula is a clinical diagnosis and includes all disorders affecting scapula positioning and movement whatever its etiology. Scapular winging is a subtype of scapular dyskinesia due to a dynamic prominence of the medial border of the scapula (DSW) secondary to neuromuscular imbalance in the scapulothoracic stabilizer muscles. The two most common causes of DSW are microtraumatic or idiopathic lesions of the long thoracic nerve (that innerves the serratus anterior) or the accessory nerve (that innerves the trapezius). Diagnosis of DSW is clinical and electromyographic. Use of magnetic resonance imaging (MRI) could be of interest to distinguish lesion secondary to a long thoracic nerve from accessory nerve and to rule out scapular dyskinesia related to other shoulder disorders. Causal neuromuscular lesion diagnosis in DSW is challenging. Clinical examinations, combined with scapular MRI, could help to their specific diagnosis, determining their stage, ruling out differential diagnosis and thus give raise to more targeted treatment.
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Discinesias/diagnóstico , Discinesias/fisiopatologia , Eletromiografia , Imageamento por Ressonância Magnética , Escápula/inervação , Músculos Superficiais do Dorso/inervação , Diagnóstico Diferencial , Humanos , Nervos Torácicos/fisiopatologiaAssuntos
Imageamento Tridimensional/métodos , Ombro/diagnóstico por imagem , Articulação Acromioclavicular/diagnóstico por imagem , Articulação Acromioclavicular/fisiologia , Adulto , Fenômenos Biomecânicos , Clavícula/diagnóstico por imagem , Clavícula/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Úmero/diagnóstico por imagem , Úmero/fisiologia , Masculino , Amplitude de Movimento Articular , Escápula/diagnóstico por imagem , Escápula/fisiologia , Ombro/fisiologia , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/fisiologia , Articulação Esternoclavicular/diagnóstico por imagem , Articulação Esternoclavicular/fisiologiaRESUMO
OBJECTIVES: (1) To compare MRI and surgical findings in patients with refractory greater trochanter pain syndrome and (2) to assess surgical outcomes. METHODS: All consecutive patients seen between 2002 and 2006 by a single clinician were selected for surgical treatment according to the following criteria: (1) tendinopathy confirmed by physical tests; (2) painful disability persisting for at least 6 months despite treatment; (3) on MRI: area of high signal intensity on T2-weighted images, in the area of gluteus medius and/or minimus tendon; and (4) absence of marked muscle atrophy or fatty degeneration. Two musculoskeletal radiologists interpreted images by consensus. A single surgeon operated on all patients. RESULTS: Eight patients met the criteria for surgery. All were women, aged 71.1 (SD: 9.4). Mean symptoms duration before surgery: 14.3 months (11.8). Surgery confirmed the presence of a tear of the lateral part of the gluteus medius tendon in all eight patients, with an associated tear of its main tendon in one patient, all tears revealed on MRI. An associated tear of the gluteus minimus tendon was present at surgery in five patients, of which three were not seen on MRI (false negative). Bursitis was confirmed in all eight patients. Steady complete remission of spontaneous and provoked (physical examination) pain was observed in seven patients and partial remission in one (mean follow-up: 22.4 months (SD: 16.3)). Six MRIs performed after 20+/-12 months showed good reinsertion of the sutured tendon. CONCLUSION: The eight MR images of tear of the lateral part of the gluteus medius tendon were all confirmed at surgery. Three of five associated tendon tears (gluteus minimus only) were not seen on MRI. Surgical treatment was very effective in all patients but one.