RESUMO
OBJECTIVE: To compare computer-based 3D-analysis for quantification of the femorotibial joint space width (JSW) using weight-bearing cone beam CT (WB-CT), non-weight-bearing multi-detector CT (NWB-CT), and weight-bearing conventional radiographs (WB-XR). DESIGN: Twenty-six participants prospectively underwent NWB-CT, WB-CT, and WB-XR of the knee. For WB-CT and NWB-CT, the average and minimal JSW was quantified by 3D-analysis of the minimal distance of any point of the subchondral tibial bone surface and the femur. Associations with mechanical leg axes and osteoarthritis were evaluated. Minimal JSW of WB-CT was further compared to WB-XR. Two-tailed p-values of <0.05 were considered significant. RESULTS: Significant differences existed of the average medial and lateral JSW between WB-CT and NWB-CT (medial: 4.7 vs 5.1 mm [P = 0.028], lateral: 6.3 vs 6.8 mm [P = 0.008]). The minimal JSW on WB-XR (medial:3.1 mm, lateral:5.8 mm) were significantly wider compared to WB-CT and NWB-CT (both medial:1.8 mm, lateral:2.9 mm, all p < 0.001), but not significantly different between WB-CT and NWB-CT (all p ≥ 0.869). Significant differences between WB-CT and NWB-CT existed in participants with varus knee alignment for the average and the minimal medial JSW (p = 0.004 and p = 0.011) and for participants with valgus alignment for the average lateral JSW (p = 0.013). On WB-CT, 25% of the femorotibial compartments showed bone-on-bone apposition, which was significantly higher when compared to NWB-CT (10%,P = 0.008) and WB-XR (8%,P = 0.012). CONCLUSION: Combining WB-CT with 3D-based assessment allows detailed quantification of the femorotibial joint space and the effect of knee alignment on JSW. WB-CT demonstrates significantly more bone-on-bone appositions, which are underestimated or even undetectable on NWB-CT and WB-XR.
Assuntos
Articulação do Joelho , Osteoartrite do Joelho , Tomografia Computadorizada de Feixe Cônico , Humanos , Joelho , Articulação do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/diagnóstico por imagem , Radiografia , Suporte de CargaRESUMO
Metal-induced artifacts impair image quality of computed tomography (CT) and magnetic resonance imaging (MRI) in patients with hip prostheses. Due to new developments in metal artifact reduction both methods can now be used for evaluation of a painful hip prosthesis. Iterative reconstruction algorithms and dual-energy scans are among the newer CT techniques for artifact reduction, while slice-encoding for metal artifact correction (SEMAC) and multi-acquisition variable-resonance image combination (MAVRIC) have introduced substantial improvements for MRI. Loosening of the hip prosthesis, osteolysis from small wear particles and pseudotumors in metal-on-metal prostheses are specific pathologies in patients with total hip arthroplasty. Other causes of painful hip prostheses are infections, fractures, tendinopathies, tendon ruptures, muscle and nerve alterations and heterotopic ossifications.
Assuntos
Algoritmos , Artroplastia de Quadril/métodos , Artefatos , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgia , Aumento da Imagem/métodos , Cirurgia Assistida por Computador/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoRESUMO
OBJECTIVES: Femoroacetabular impingement is proposed to cause early osteoarthritis (OA) in the non-dysplastic hip. We previously reported on the prevalence of femoral deformities in a young asymptomatic male population. The aim of this study was to determine the prevalence of both femoral and acetabular types of impingement in young females. METHODS: We conducted a population-based cross-sectional study of asymptomatic young females. All participants completed a set of questionnaires and underwent clinical examination of the hip. A random sample was subsequently invited to obtain magnetic resonance images (MRI) of the hip. All MRIs were read for cam-type deformities, increased acetabular depths, labral lesions, and impingement pits. Prevalence estimates of cam-type deformities and increased acetabular depths were estimated, and relationships between deformities and signs of joint damage were examined using logistic regression models. RESULTS: The study included 283 subjects, and 80 asymptomatic females with a mean age of 19.3 years attended MRI. Fifteen showed some evidence of cam-type deformities, but none were scored to be definite. The overall prevalence was therefore 0% [95% confidence interval (95% CI) 0-5%]. The prevalence of increased acetabular depth was 10% (95% CI 5-19). No association was found between increased acetabular depth and decreased internal rotation of the hip. Increased acetabular depth was not associated with signs of labral damage. CONCLUSIONS: Definite cam-type deformities in women are rare compared to men, whereas the prevalence of increased acetabular depth is higher, suggesting that femoroacetabular impingement has different gender-related biomechanical mechanisms.
Assuntos
Impacto Femoroacetabular/epidemiologia , Acetábulo/patologia , Adolescente , Estudos Transversais , Feminino , Impacto Femoroacetabular/diagnóstico , Impacto Femoroacetabular/patologia , Impacto Femoroacetabular/fisiopatologia , Articulação do Quadril/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Prevalência , Amplitude de Movimento Articular , Fatores Sexuais , Suíça/epidemiologia , Adulto JovemRESUMO
The objective of this study is to evaluate feasibility, accuracy and time requirements of MR/CT image fusion of the lumbar spine after spondylodesis. Sagittal MR and CT images derived from standard imaging protocols (sagittal T2-weighted MR/sagittal reformatted multi-planar-reformation of the CT) of the lumbar spine with correct (n = 5) and incorrect (n = 5) implant position were fused by two readers (R1, R2) using OsiriX in two sessions placing one (session 1) or two (session 2) reference point(s) on the dorsal tip(s) of the cranial and caudal endplates from the second lumbar to the first sacral vertebra. R1 was an experienced musculoskeletal radiologist; R2 a spine surgeon, both had received a short training on the software tool. Fusion times and fusion accuracy, defined as the largest deviation between MR and CT in the median sagittal plane on the ventral tip of the cranial end plate of the most cranial vertebra visible on the CT, were measured in both sessions. Correct or incorrect implant position was evaluated upon the fused images for all patients by an experienced senior staff musculoskeletal radiologist. Mean fusion time (session 1/session 2; in seconds) was 100.4/95 (R1) and 104.2/119.8 (R2). Mean fusion deviation (session 1/session 2; in mm) was 1.24/2.20 (R1) and 0.79/1.62 (R2). The correct/incorrect implant position was identified correctly in all cases. In conclusion, MR/CT image fusion of the spine with metallic implants is feasible, fast, accurate and easy to implement in daily routine work.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Fusão Vertebral/métodos , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia , Tomografia Computadorizada por Raios X/métodos , Estudos de Viabilidade , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Vértebras Lombares/cirurgia , Coluna Vertebral/patologiaRESUMO
BACKGROUND: Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. PURPOSE: To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. MATERIAL AND METHODS: Transverse T(1) maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T(1) maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. RESULTS: T(1) of unenhanced hyaline cartilage of the glenoid was 568+/-34 ms. T(1) of unenhanced fibrous cartilage of the labrum was 552+/-38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T(1)(Gd) values in fibrous cartilage. T(1) and triangle Delta R(1) values of hyaline and fibrous cartilage after 2.5 hours were 351+/-16 ms and 1.1+/-0.09 s(-1), and 332+/-31 ms and 1.2+/-0.1 s(-1), respectively. CONCLUSION: A significant decrease in T(1)(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium.
Assuntos
Cartilagem Articular/anatomia & histologia , Imageamento por Ressonância Magnética/métodos , Articulação do Ombro/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Meios de Contraste/administração & dosagem , Feminino , Gadolínio DTPA/administração & dosagem , Humanos , Injeções Intra-Articulares , Masculino , Estatísticas não ParamétricasRESUMO
BACKGROUND: The natural history of massive rotator cuff tears is not well known. The purpose of this study was to determine the clinical and structural mid-term outcomes in a series of nonoperatively managed massive rotator cuff tears. METHODS: Nineteen consecutive patients (twelve men and seven women; average age, sixty-four years) with a massive rotator cuff tear, documented by magnetic resonance imaging, were identified retrospectively. There were six complete tears of two rotator cuff tendons and thirteen complete tears of three rotator cuff tendons. All patients were managed exclusively with nonoperative means. Nonoperative management was chosen when a patient had low functional demands and relatively few symptoms and/or if he or she refused to have surgery. For the purpose of this study, patients were examined clinically and with standard radiographs and magnetic resonance imaging. RESULTS: After a mean duration of follow-up of forty-eight months, the mean relative Constant score was 83% and the mean subjective shoulder value was 68%. The score for pain averaged 11.5 points on a 0 to 15-point visual analogue scale in which 15 points represented no pain. The active range of motion did not change over time. Forward flexion and abduction averaged 136 degrees; external rotation, 39 degrees; and internal rotation, 66 degrees. Glenohumeral osteoarthritis progressed (p = 0.014), the acromiohumeral distance decreased (p = 0.005), the size of the tendon tear increased (p = 0.003), and fatty infiltration increased by approximately one stage in all three muscles (p = 0.001). Patients with a three-tendon tear showed more progression of osteoarthritis (p = 0.01) than did patients with a two-tendon tear. Four of the eight rotator cuff tears that were graded as reparable at the time of the diagnosis became irreparable at the time of final follow-up. CONCLUSIONS: Patients with a nonoperatively managed, moderately symptomatic massive rotator cuff tear can maintain satisfactory shoulder function for at least four years despite significant progression of degenerative structural joint changes. There is a risk of a reparable tear progressing to an irreparable tear within four years.
Assuntos
Lesões do Manguito Rotador , Acrômio/patologia , Tecido Adiposo/patologia , Idoso , Progressão da Doença , Feminino , Seguimentos , Humanos , Úmero/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Osteoartrite/fisiopatologia , Medição da Dor , Amplitude de Movimento Articular/fisiologia , Estudos Retrospectivos , Fatores de Risco , Rotação , Manguito Rotador/patologia , Manguito Rotador/fisiopatologia , Articulação do Ombro/fisiopatologia , Dor de Ombro/fisiopatologia , Resultado do TratamentoRESUMO
We released the infraspinatus tendons of six sheep, allowed retraction of the musculotendinous unit over a period of 40 weeks and then performed a repair. We studied retraction of the musculotendinous unit 35 weeks later using CT, MRI and macroscopic dissection. The tendon was retracted by a mean of 4.7 cm (3.8 to 5.1) 40 weeks after release and remained at a mean of 4.2 cm (3.3 to 4.7) 35 weeks after the repair. Retraction of the muscle was only a mean of 2.7 cm (2.0 to 3.3) and 1.7 cm (1.1 to 2.2) respectively at these two points. Thus, the musculotendinous junction had shifted distally by a mean of 2.5 cm (2.0 to 2.8) relative to the tendon. Sheep muscle showed an ability to compensate for approximately 60% of the tendon retraction in a hitherto unknown fashion. Such retraction may not be a quantitatively reliable indicator of retraction of the muscle and may overestimate the need for elongation of the musculotendinous unit during repair.
Assuntos
Lesões do Manguito Rotador , Animais , Fenômenos Biomecânicos , Feminino , Imageamento por Ressonância Magnética/métodos , Fibras Musculares Esqueléticas/patologia , Osteotomia/métodos , Manguito Rotador/patologia , Manguito Rotador/cirurgia , Ruptura/cirurgia , Ovinos , Traumatismos dos Tendões/diagnóstico por imagem , Traumatismos dos Tendões/patologia , Traumatismos dos Tendões/cirurgia , Fatores de Tempo , Tomografia Computadorizada por Raios X/métodosRESUMO
BACKGROUND: The clinical outcome for patients with documented rerupture after open repair of one or more rotator cuff tendons is not well known. The purpose of this study was to evaluate the clinical outcomes of a consecutive series of rotator cuff reruptures after repair and to provide information concerning the advisability of rotator cuff repair in situations in which there may be a high probability of rerupture. METHODS: During prospective follow-up after rotator cuff repairs, we detected, with magnetic resonance imaging, structural failure of the repair in twenty patients, who had a mean age of fifty-nine years at the time of the rotator cuff repair. All patients were clinically examined for the purpose of this report at a mean of thirty-eight months. RESULTS: The reruptures invariably involved the originally torn tendon but were smaller than the original tear in sixteen of the twenty patients. Fatty degeneration of the supraspinatus and infraspinatus muscles, atrophy of the supraspinatus muscle, and glenohumeral osteoarthritis progressed significantly from the preoperative state (p < 0.05). At the time of the most recent follow-up, the subjective shoulder value averaged 75 percent of the value for a normal shoulder. Eleven patients were very satisfied with the result, six were satisfied, two were disappointed, and one was dissatisfied. The mean relative score according to the system of Constant and Murley had increased from 49 percent of the score for a normal shoulder preoperatively to 83 percent postoperatively (p = 0.0001). Pain had decreased significantly, and the ranges of active, pain-free forward elevation and abduction as well as the abduction strength had improved significantly (p < 0.05). The clinical outcome was significantly correlated with the size of the postoperative tear, the stage of postoperative fatty muscle degeneration of the infraspinatus and subscapularis, the postoperative acromiohumeral distance, and the degree of postoperative glenohumeral osteoarthritis (p < 0.05). CONCLUSIONS: This study documents that an attempt at rotator cuff repair significantly decreases pain (p = 0.0026) and significantly improves function (p = 0.0005) and strength (p = 0.0137) even if magnetic resonance imaging documents that the repair has failed. This finding suggests that the potential for rerupture should not be considered a formal contraindication to an attempt at repair if optimal functional recovery is the goal of treatment.
Assuntos
Lesões do Manguito Rotador , Manguito Rotador/cirurgia , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recidiva , Manguito Rotador/patologia , Ruptura , Resultado do TratamentoRESUMO
STUDY DESIGN: A reliability study was conducted. OBJECTIVES: To develop a classification system for lumbar disc degeneration based on routine magnetic resonance imaging, to investigate the applicability of a simple algorithm, and to assess the reliability of this classification system. SUMMARY OF BACKGROUND DATA: A standardized nomenclature in the assessment of disc abnormalities is a prerequisite for a comparison of data from different investigations. The reliability of the assessment has a crucial influence on the validity of the data. Grading systems of disc degeneration based on state of the art magnetic resonance imaging and corresponding reproducibility studies currently are sparse. METHODS: A grading system for lumbar disc degeneration was developed on the basis of the literature. An algorithm to assess the grading was developed and optimized by reviewing lumbar magnetic resonance examinations. The reliability of the algorithm in depicting intervertebral disc alterations was tested on the magnetic resonance images of 300 lumbar intervertebral discs in 60 patients (33 men and 27 women) with a mean age of 40 years (range, 10-83 years). All scans were analyzed independently by three observers. Intra- and interobserver reliabilities were assessed by calculating kappa statistics. RESULTS: There were 14 Grade I, 82 Grade II, 72 Grade III, 68 Grade IV, and 64 Grade V discs. The kappa coefficients for intra- and interobserver agreement were substantial to excellent: intraobserver (kappa range, 0.84-0.90) and interobserver (kappa range, 0.69-0.81). Complete agreement was obtained, on the average, in 83.8% of all the discs. A difference of one grade occurred in 15.9% and a difference of two or more grades in 1.3% of all the cases. CONCLUSION: Disc degeneration can be graded reliably on routine T2-weighted magnetic resonance images using the grading system and algorithm presented in this investigation.
Assuntos
Deslocamento do Disco Intervertebral/diagnóstico , Vértebras Lombares/patologia , Imageamento por Ressonância Magnética , Algoritmos , Deslocamento do Disco Intervertebral/classificação , Variações Dependentes do Observador , Reprodutibilidade dos TestesRESUMO
Imaging of the hip abductors plays an increasing role for the evaluation of greater trochanteric pain in patients with and without total hip arthroplasty. This review article addresses the anatomy of the hip abductors and their intervening bursae. It highlights different possible imaging appearances such as tendinopathy or partial and full thickness tears of the gluteal tendons. Muscle atrophy or fatty degeneration of the gluteal muscles is an important reason for limping. Inflammatory diseases such as hydroxyapatite crystal deposition disease or spondylarthritis have to be considered. Knowledge of these different entities is important to achieve optimal treatment and outcomes.
Assuntos
Artralgia/diagnóstico , Articulação do Quadril/patologia , Imageamento por Ressonância Magnética/métodos , Músculo Esquelético/lesões , Músculo Esquelético/patologia , Traumatismos dos Tendões/diagnóstico , Artralgia/etiologia , Humanos , Traumatismos dos Tendões/complicações , TendõesRESUMO
The direct anterior approach in total hip replacement anatomically offers the chance to minimise soft-tissue trauma because an intermuscular and internervous plane is explored. This motivated us to abandon our previously used transgluteal approach and to adopt the direct anterior approach for total hip replacement. Using MRI, we performed a retrospective comparative study of the direct anterior approach with the transgluteal approach. There were 25 patients in each group. At one year post-operatively all the patients underwent MRI of their replaced hips. A radiologist graded the changes in the soft-tissue signals in the abductor muscles. The groups were similar in terms of age, gender, body mass index, complexity of the reconstruction and absence of symptoms. Detachment of the abductor insertion, partial tears and tendonitis of gluteus medius and minimus, the presence of peri-trochanteric bursal fluid and fatty atrophy of gluteus medius and minimus were significantly less pronounced and less frequent when the direct anterior approach was used. There was no significant difference in the findings regarding tensor fascia lata between the two approaches. We conclude that use of the direct anterior approach results in a better soft-tissue response as assessed by MRI after total hip replacement. However, the impact on outcome needs to be evaluated further.
Assuntos
Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Músculo Esquelético/lesões , Traumatismos dos Tendões/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Estudos Retrospectivos , Traumatismos dos Tendões/diagnóstico , Resultado do TratamentoRESUMO
The longitudinal relaxation time T(1) of native cartilage is frequently assumed to be constant. To redress this, the spatial variation of T(1) in unenhanced healthy human knee cartilage in different compartments and cartilage layers was investigated. Knees of 25 volunteers were examined on a 1.5 T MRI system. A three-dimensional gradient-echo sequence with a variable flip angle, in combination with parallel imaging, was used for rapid T(1) mapping of the whole knee. Regions of interest (ROIs) were defined in five different cartilage segments (medial and lateral femoral cartilage, medial and lateral tibial cartilage and patellar cartilage). Pooled histograms and averaged profiles across the cartilage thickness were generated. The mean values were compared for global variance using the Kruskal-Wallis test and pairwise using the Mann-Whitney U-test. Mean T(1) decreased from 900-1100 ms in superficial cartilage to 400-500 ms in deep cartilage. The averaged T(1) value of the medial femoral cartilage was 702+/-68 ms, of the lateral femoral cartilage 630+/-75 ms, of the medial tibial cartilage 700+/-87 ms, of the lateral tibial cartilage 594+/-74 ms and of the patellar cartilage 666+/-78 ms. There were significant differences between the medial and lateral compartment (p<0.01). In each cartilage segment, T(1) decreased considerably from superficial to deep cartilage. Only small variations of T(1) between different cartilage segments were found but with a significant difference between the medial and lateral compartments.
Assuntos
Cartilagem Articular/anatomia & histologia , Articulação do Joelho/anatomia & histologia , Adolescente , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Masculino , Estatísticas não Paramétricas , Adulto JovemRESUMO
Trochlear dysplasia is an important risk factor for patellar instability. Because of a decreased trochlear depth in combination with a low lateral femoral condyle, the patella cannot engage properly in the trochlea. Trochleoplasty is a surgical procedure, which strives to correct such bony abnormalities. The aim of this study was to describe morphological features of trochlear dysplasia and the corrective changes after trochleoplasty on CT scan. The study group consists of 17 knees with trochlear dysplasia having undergone trochleoplasty for recurrent patellofemoral dislocation at a mean age of 22.4 years. The evaluation consisted in pre- and postoperative measurements on the proximal and distal trochlea on transverse CT scans in order to determine the morphological features. We measured the transverse position and depth of the trochlear groove, the transverse position of the patella, the ratio between the posterior patellar edge and the trochlear groove, the lateral patellar inclination angle, the sulcus angle, and the lateral trochlear slope. The trochlear groove lateralised a mean of 6.1 mm in the proximal aspect and 2.5 mm in the distal aspect of the trochlea, while the patella medialised a mean of 5 mm. Preoperatively the patella was lateral in relation to the trochlear groove in 13 cases, neutral in two cases, and medial in two cases. Postoperatively it was lateral in four cases, in neutral position in seven cases, and medialised in six cases, referenced to the trochlear groove. The trochlear depth increased from 0 to 5.9 mm postoperatively in the proximal aspect of the trochlea, and from 5.5 to 8.3 mm postoperatively in the distal trochlea. The lateral patellar inclination angle decreased from a mean of 21.9 degrees to a mean of 7.8 degrees . The sulcus angle decreased from a mean of 172.1 degrees to a mean of 133 degrees in the proximal trochlea and from a mean of 141.9 degrees to a mean of 121.7 degrees in the distal trochlea. The lateral trochlear slope changed from 2.8 degrees to 22.7 degrees in the proximal and from 14.9 degrees to 26.9 degrees in the distal part of the trochlea. In the CT scan patients with trochlear dysplasia demonstrated a poor depth, or even a flat or convex trochlea with a greater sulcus and lateral trochlear slope angle, a lateralised patella to the trochlear groove with poor congruency, and a greater lateral patellar inclination angle. Trochleoplasty can correct the pathological features of trochlear dysplasia by surgically creating more normal anatomy. The goal of this surgical procedure is to steepen and lateralise the trochlear groove for a better engagement of the patella.
Assuntos
Doenças do Desenvolvimento Ósseo/diagnóstico por imagem , Doenças do Desenvolvimento Ósseo/cirurgia , Fêmur , Instabilidade Articular/diagnóstico por imagem , Instabilidade Articular/cirurgia , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteotomia , Adolescente , Adulto , Fêmur/diagnóstico por imagem , Fêmur/fisiopatologia , Fêmur/cirurgia , Humanos , Tomografia Computadorizada por Raios XRESUMO
Magnetic resonance (MR) imaging of the knee is a robust method for the evaluation of internal derangements. A knowledge of the well known technical and anatomical pitfalls avoids, in most cases, diagnostic errors. However, the differentiation between meniscocapsular separation and normal anatomy remains challenging. The high prevalence of abnormal MR findings, especially meniscal tears with up to 63% on the asymptomatic contralateral side, has to be considered in patient management.
Assuntos
Erros de Diagnóstico , Aumento da Imagem/métodos , Artropatias/diagnóstico , Traumatismos do Joelho/diagnóstico , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Humanos , Guias de Prática Clínica como Assunto , Padrões de Prática Médica , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Ultrasound and MR imaging are competitive imaging modalities for the diagnosis of pathologic conditions of the biceps tendon. MR imaging has substantial advantages over ultrasound because biceps tendon lesions are most commonly located in the proximal part where lesions are hidden under the acromion for ultrasound assessment. The value of MR arthrography is substantiated by the capability to assess associated diagnoses which are otherwise difficult to assess. Associated diagnoses include full- and partial thickness tears of supraspinatus and subscapularis tendons, pulley lesions, and adhesive capsulitis (frozen shoulder). Moreover, MR arthrography is the method of choice for the assessment of superior labral anterior posterior (SLAP) lesions.
Assuntos
Artrografia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Lesões do Ombro , Traumatismos dos Tendões/diagnóstico , Tenossinovite/diagnóstico , Diagnóstico Diferencial , Humanos , Aumento da Imagem , Manguito Rotador/patologia , Lesões do Manguito Rotador , Ruptura , Sensibilidade e Especificidade , Ombro/patologia , Dor de Ombro/etiologia , Tendões/patologia , UltrassonografiaRESUMO
PURPOSE: To investigate the frequency and characteristics of Schmorl nodes in an elderly population and to correlate these findings with degenerative spinal changes. MATERIALS AND METHODS: Cadaveric thoracic and lumbar spines were removed at autopsy (mean age at death, 68.2 years; range, 43-93 years). Parasagittal sections of approximately 5-mm thickness were obtained and radiographed. At each of 3,300 endplates from T1 to L5, the presence of Schmorl nodes was noted. Vertebral endplate contour was analyzed, and abnormalities of the discovertebral junction were noted. The height of each interspace was measured, and the presence or absence of vacuum phenomena and spondylosis was recorded. RESULTS: Schmorl nodes were found in 58 specimens and were multiple in 41. Of 3,300 vertebral endplates, 225 revealed Schmorl nodes: 88 cranial and 137 caudal. More than 182 were between T7 and L2. Schmorl nodes correlated with disk space loss (P <.001) but not with evidence of advanced disk degeneration: marked disk space loss (P =.53), vacuum phenomena (P =.82), or discogenic sclerosis or erosion (P =.35). Schmorl nodes were associated with claw (P <.001) but not traction (P =.72) osteophytes. Straight (P <.001) and fractured (P <.001) vertebral endplates were associated with Schmorl nodes. CONCLUSION: Schmorl nodes are common in the spines in an elderly population, with a frequency similar to that in a younger population. Schmorl nodes are associated with moderate but not advanced degenerative changes. Geometric observations regarding the vertebral endplates support the concept that Schmorl nodes are caused by an abnormality of the discovertebral junction.
Assuntos
Vértebras Lombares/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Técnicas In Vitro , Vértebras Lombares/patologia , Pessoa de Meia-Idade , Radiografia , Doenças da Coluna Vertebral/diagnóstico por imagem , Doenças da Coluna Vertebral/patologia , Vértebras Torácicas/patologiaRESUMO
PURPOSE: To establish quantitative and qualitative magnetic resonance (MR) criteria for the diagnosis of trochlear dysplasia. MATERIALS AND METHODS: MR images were analyzed in 16 consecutive patients with and 23 without trochlear dysplasia. The standard of reference was a true lateral radiograph of the knee. Quantitative and qualitative MR criteria were assessed. RESULTS: In patients with trochlear dysplasia, the trochlear groove was significantly less deep than that in control subjects. The most accurate measurement was 3 cm above the femorotibial joint space (P: <.001), where a trochlear depth of 3 mm or less had a sensitivity of 100% and a specificity of 96%. The ventral trochlear prominence between the supratrochlear femoral cortex and the most ventral point of the trochlear floor (midsagittal section) was always larger than 6.9 mm in dysplastic trochleae. A facet ratio of less than 2:5 (medial to lateral) 3 cm above joint space level had a sensitivity of 100% and a specificity of 96%. A nipplelike anterior prominence at the superior end of the femoral trochlea on midsagittal images was a specific (91%) qualitative criterion. CONCLUSION: Dysplasia of the femoral trochlea can be diagnosed reliably by using quantitative or qualitative criteria on midsagittal or transverse MR images obtained 3 cm above the femorotibial joint space.
Assuntos
Artralgia/diagnóstico , Doenças do Desenvolvimento Ósseo/diagnóstico , Fêmur/patologia , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Artralgia/etiologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Patela/patologia , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
The diagnostic assessment of low back pain should predominantly be based on history and clinical examination rather than on imaging studies. The problem of diagnostic imaging in low back pain is related to the high rate of asymptomatic morphological alterations in the lumbar spine. The diagnosis should therefore not be guided by findings in imaging. The imaging studies (standard radiographs and MRI) should verify the clinically suspected diagnosis and further lead to imaging guided injection studies (e.g. nerve root block, facet joint block, sacro-iliac joint block, provocative discography) to differentiate between symptomatic and asymptomatic morphological alterations. With longlasting local anaesthetics and steroids it is possible to achieve a diagnostic as well as a therapeutic effect.
Assuntos
Diagnóstico por Imagem , Dor Lombar/etiologia , Bloqueio Nervoso , Doenças da Coluna Vertebral/diagnóstico , Diagnóstico Diferencial , Humanos , Dor Lombar/terapia , Doenças da Coluna Vertebral/terapiaRESUMO
PURPOSE: To evaluate trochanteric anatomy with magnetic resonance (MR) imaging, bursography, MR bursography, and anatomic analysis. MATERIALS AND METHODS: T1-weighted and fat-saturated T2-weighted (transverse, sagittal, coronal, and coronal oblique planes) MR imaging of the greater trochanter was performed in 10 cadaveric hips and 12 hips of asymptomatic volunteers. Three bursae comprising the trochanteric bursa complex were injected, and conventional radiography and MR imaging were performed. The specimens were sectioned for anatomic analysis, corresponding to the MR imaging planes. Tendon attachments and bursal localization were related to the facets of the greater trochanter. RESULTS: The bony surface of the greater trochanter consists of four facets: anterior, lateral, posterior, and superoposterior. The gluteus medius muscle attaches to the superoposterior and lateral facets. The gluteus minimus muscle attaches to the anterior facet. The trochanteric bursa covered the posterior facet and the lateral insertion of the gluteus medius muscle. The subgluteus medius bursa was located in the superior part of the lateral facet, underneath the gluteus medius tendon. The subgluteus minimus bursa lies in the area of the anterior facet, underneath the gluteus minimus tendon, medial and cranial to its insertion, and extends medially covering the distal anterior part of the hip joint capsule. The trochanteric bursa is delineated with fat on both sides and can be seen on transverse nonenhanced T1-weighted images as a fine line curving around the posterior part of the trochanter. CONCLUSION: MR imaging and bursography provide detailed information about the anatomy of tendinous attachments of the abductor muscles and the bursal complex of the greater trochanter.
Assuntos
Bolsa Sinovial/anatomia & histologia , Fêmur/anatomia & histologia , Articulação do Quadril/anatomia & histologia , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de ReferênciaRESUMO
PURPOSE: Whiplash injuries are frequent in industrialized countries. The acute and chronic symptoms following such injuries are incompletely understood and objective clinical or imaging findings are rare. Several authors have suspected that rear end collisions occurring when the head is rotated may result in tears of the alar ligaments. There has been experimental proof that a torn alar ligament increases the rotation of the C0/C1 and C1/C2 segments to the contralateral side. Functional cross sectional imaging has therefore been proposed to diagnose injuries of the alar ligaments. So far, published data on normal ranges of rotation in an asymptomatic population have been sparse. The aim of this study was to determine by MR imaging the normal range of rotation in the first three cervical segments and their relation to the morphology of the alar ligaments and the occipito-atlantoaxial joints. MATERIAL AND METHODS: Functional MR imaging of the craniocervical junction in maximum active left and right head rotation was performed in 50 healthy volunteers with a mean age of 29.8 years (31 men, 19 women, range 19-47 years). Measurements were independently performed by two musculoskeletal radiologists to assess interobserver error. The results were correlated with gender and age, with morphological findings in the occipito-atlantoaxial joints (i.e. joint symmetry, joint effusions, dens position), and with the form, course and symmetry of the alar ligaments. RESULTS: The mean range of rotation for the C0/C1 joint was 2.7 degrees (standard deviation [SD] 3.3 degrees)/3.3 degrees (SD 3.6 degrees) (right/left) and at the C1/C2 level 38 degrees (SD 6.5 degrees)/37.8 degrees (SD 6.4 degrees). The mean differences in left/right rotation were: C0/C1 3.5 degrees (SD 2.8 degrees) and C1/C2 6.3 degrees (SD 4.4 degrees). No correlation was found between segmental rotation and morphological characteristics of the craniocervical joints or ligament structures. CONCLUSION: There is wide variation of segmental motion in the upper cervical spine. Differences in right-to-left rotation are frequently encountered in an asymptomatic population. Therefore, these measurements are unsuitable for indirect diagnosis of soft tissue lesions after whiplash injury and should not be used as a basis for treatment guidelines.