RESUMO
Calcinosis is a typical feature of systemic sclerosis (SSc) and can be found in many different tissues including the superficial soft tissues, periarticular structures, muscles, and tendons. It can also provoke erosive changes on bones. Investigation is conducted most often with plain radiographs. However, when a more detailed assessment is necessary, multidetector computed tomography (MDCT) is helpful owing to its multiplanar reformat (MPR) ability. The purpose of this review is to provide an overview of the various appearances of calcinosis in SSc patients as visualized at MDCT.
Assuntos
Calcinose/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Escleroderma Sistêmico/diagnóstico por imagem , HumanosRESUMO
OBJECTIVE: To examine the outcomes of hand radiographic x-rays in patients with systemic sclerosis (SSc) and to identify risk factors for the progression of hand radiographic lesions in a prospective cohort. METHODS: Dual time-point x-rays were systematically performed after a median interval of 5 years (range 4-7 years) in 103 consecutively recruited patients with SSc. Univariate and multivariate Cox proportional hazards models evaluated predictors of progression of hand radiographic lesions. RESULTS: Radiographic progression of erosive arthritis, acro-osteolysis, calcinosis and flexion contracture occurred in 24, 22, 27 and 18 patients, respectively. Multivariate Cox regression analysis did not identify any predictor of the progression of erosive arthritis. Digital ulcers were shown independently to predict the progression of acro-osteolysis and calcinosis (HR 12.43, 95% CI 1.97 to 88.40 and 3.16, 95% CI 1.22% to 9.43%, respectively). The diffuse cutaneous subset was shown to be an independent predictor of the progression of flexion contracture (HR 7.52, 95% CI 1.21 to 43.93). CONCLUSION: The results highlight the striking level of hand radiographic lesions in SSc and suggest close monitoring of patients with the diffuse cutaneous subset for the occurrence or worsening of this complication. The results also show that severe peripheral vascular involvement predicts both acro-osteolysis and calcinosis, highlighting their vascular background.
Assuntos
Mãos/diagnóstico por imagem , Escleroderma Sistêmico/diagnóstico por imagem , Acro-Osteólise/diagnóstico por imagem , Acro-Osteólise/etiologia , Artrite/diagnóstico por imagem , Artrite/etiologia , Calcinose/diagnóstico por imagem , Calcinose/etiologia , Progressão da Doença , Métodos Epidemiológicos , Feminino , Ossos da Mão/diagnóstico por imagem , Articulação da Mão/diagnóstico por imagem , Humanos , Masculino , Radiografia , Escleroderma Sistêmico/complicaçõesRESUMO
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by progressive damage of synovial-lined joints and variable extra-articular manifestations. Synovitis is usually found in the wrist, metacarpophalangeal, proximal interphalangeal and metatarsophalangeal joints. For these reasons, we believe that ultrasound with power doppler can be used for the detection and monitoring of synovitis with a simplified "hands and feet" protocol. In this article, we will describe this protocol used daily in our institution for early diagnosis and therapeutic management of this disease.
Assuntos
Artrite Reumatoide/diagnóstico por imagem , Articulações do Pé/diagnóstico por imagem , Articulação da Mão/diagnóstico por imagem , Ultrassonografia Doppler em Cores/métodos , Artrite Reumatoide/classificação , Humanos , Sensibilidade e Especificidade , Membrana Sinovial/diagnóstico por imagem , Sinovite/classificação , Sinovite/diagnóstico por imagem , TransdutoresRESUMO
The new diagnostic criteria for spondyloarthropathy include MRI. MRI frequently allows early diagnosis of inflammatory lesions of the spine and sacroiliac joints in patients with normal plain films. Moreover, MRI is useful for the detection and quantification of inflammatory and structural lesions, and to assess disease activity.
Assuntos
Aumento da Imagem , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Articulação Sacroilíaca/patologia , Espondilite Anquilosante/diagnóstico , Adulto , Vértebras Cervicais/patologia , Discite/diagnóstico , Progressão da Doença , Feminino , Humanos , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Espondilite Anquilosante/classificação , Vértebras Torácicas/patologiaRESUMO
The new diagnostic criteria for ankylosing spondylitis include MRI. MRI frequently allows early diagnosis of inflammatory lesions in patients with normal plain films. In addition, MRI is useful for the detection and quantification of inflammatory and structural lesions, and to assess disease activity.
Assuntos
Aumento da Imagem , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Espondilite Anquilosante/diagnóstico , Adolescente , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Articulação Sacroilíaca/patologia , Sacro/patologia , Espondilite Anquilosante/etiologia , Vértebras Torácicas/patologia , Adulto JovemRESUMO
Dedifferentiated chondrosarcomas are highly malignant tumors characterized by conventional low-grade chondrosarcoma with abrupt transition to foci that have dedifferentiated into a higher-grade noncartilaginous more aggressive sarcoma. The dedifferentiated component, an osteosarcoma or fibrosarcoma, determines the prognosis. Its identification is key for management. A diagnosis of dedifferentiated chondrosarcoma should be suggested by the presence of "tumoral dimorphism" with cartilaginous component and aggressive lytic component invading adjacent soft tissues.
Assuntos
Neoplasias Ósseas/diagnóstico , Condrossarcoma/diagnóstico , Idoso , Medula Óssea/diagnóstico por imagem , Medula Óssea/patologia , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/patologia , Cartilagem/diagnóstico por imagem , Cartilagem/patologia , Desdiferenciação Celular , Condrossarcoma/diagnóstico por imagem , Condrossarcoma/patologia , Feminino , Fêmur/diagnóstico por imagem , Fêmur/patologia , Fibrossarcoma/diagnóstico , Fibrossarcoma/diagnóstico por imagem , Fibrossarcoma/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Osteólise/diagnóstico , Osteólise/diagnóstico por imagem , Osteólise/patologia , Osteossarcoma/diagnóstico , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/patologia , Prognóstico , Tíbia/diagnóstico por imagem , Tíbia/patologia , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVES: Painful osteoarthritis (OA) of the hand is common and a validated ultrasound (US) scoring system would be valuable for epidemiological and therapeutic outcome studies. US is increasingly used to assess peripheral joints, though most of the US focus in rheumatic diseases has been on rheumatoid arthritis. We aimed to develop a preliminary US hand OA scoring system, initially focusing on relevant pathological features with potentially high reliability. METHODS: A group of experts in the fields of OA, US and novel tool development agreed on domains and suggested scaling of the items to be used in US hand OA scoring systems. A multi-observer reliability exercise was then performed to evaluate the draft items. RESULTS: Synovitis (grey scale and Power Doppler) and osteophytes (representing activity and damage domains) were included and evaluated as the initial components of the scoring system. All three features were evaluated for their presence/absence and if present were scored using a 1-3 scale. The reliability exercise demonstrated intra-reader kappa values of 0.444-1.0, 0.211-1.0 and 0.087-1.0 for grey scale synovitis, power Doppler and osteophytes respectively. Inter-reader reliability kappa values were 0.398, 0.327 and 0.530 grey-scale synovitis, power Doppler and osteophytes respectively. Without extensive standardisation, both intra- and inter-reader reliability were moderately good. CONCLUSIONS: The draft scoring system demonstrated substantive to almost perfect percentage exact agreement on the presence/absence of the selected OA features and moderate to substantive percentage exact agreement on semi-quantitative grading. This preliminary process provides a good basis from which to further develop an US outcome tool for hand OA that has the potential to be utilised in multicentre clinical trials.
Assuntos
Articulação da Mão/diagnóstico por imagem , Indicadores Básicos de Saúde , Osteoartrite/diagnóstico por imagem , Articulação da Mão/fisiopatologia , Humanos , Variações Dependentes do Observador , Osteoartrite/fisiopatologia , Osteófito/diagnóstico por imagem , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Sinovite/diagnóstico por imagem , Sinovite/fisiopatologia , Ultrassonografia DopplerRESUMO
We report the first case of multifocal Scedosporium apiospermum spondylitis in a cystic fibrosis patient. The infection, which occurred during voriconazole prophylaxis, disseminated contiguously from the base of the left lung and pleura and spread to vertebrae via the epidural space. S. apiospermum osteoarticular infections are rare, and are difficult to diagnose and cure because of their resistance to anti-fungal drugs.
Assuntos
Antifúngicos/uso terapêutico , Fibrose Cística/complicações , Micetoma/tratamento farmacológico , Pleurisia/complicações , Scedosporium/patogenicidade , Espondilite/microbiologia , Vértebras Torácicas/microbiologia , Adulto , Caspofungina , Fibrose Cística/microbiologia , Quimioterapia Combinada , Equinocandinas/uso terapêutico , Humanos , Hospedeiro Imunocomprometido , Lipopeptídeos , Masculino , Pleurisia/microbiologia , Pirimidinas/uso terapêutico , Scedosporium/efeitos dos fármacos , Espondilite/complicações , Espondilite/tratamento farmacológico , Triazóis/uso terapêutico , VoriconazolRESUMO
Man, with his erect posture, evolves in a world subject to the laws of gravity. His spine reflects these constraints. The morphology and static of human spine and biomechanical relationships between spine and pelvis are in direct relation with bipedia. Owing to this position the pelvis widened and straightened, characteristic sagittal spinal curves appeared and the perispinal muscles were deeply reorganized. Each pelvis is characterized by an important anatomical landmark: the pelvic incidence that reflects the sagittal morphology of the pelvis. Based on this anatomical characteristic, a chain of reactions determines the more efficient equilibrium of the whole body in the sagittal plane in term of energy consumption. Incidence affects the sacral slope, which determines lumbar lordosis, which itself influences pelvic tilt, thoracic kyphosis, and even hip and knee position. All these landmarks can easily be studied on a sagittal radiograph. Knowledge of these functional relationships is essential to understand the origin of low back pain, sagittal imbalance and above all before surgical treatment of spine disorders especially when arthrodesis is considered.
Assuntos
Ossos Pélvicos/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Idoso , Artroplastia de Quadril , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/diagnóstico por imagem , Humanos , Articulação do Joelho/diagnóstico por imagem , Cifose/diagnóstico por imagem , Lordose/diagnóstico por imagem , Dor Lombar/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural/fisiologia , Postura/fisiologia , Radiografia , Sacro/diagnóstico por imagem , Curvaturas da Coluna Vertebral/diagnóstico por imagem , Doenças da Coluna Vertebral/diagnóstico por imagem , Fusão Vertebral , Espondilolistese/cirurgia , Vértebras Torácicas/diagnóstico por imagemRESUMO
Man is standing up and he moves himself in a world subject to the gravity's laws. His spine reflects these constraints. Each bivertebral unit that composes the long supple stem of the spine has an anatomic cohesion with some mobility. The mobility of the spine is the sum of the motilities of its elementary units. Despite the criticisms, all deserved, the dynamic radiographies in flexion (seating position) and in extension (standing position, lower limbs straight and buttocks wedged) give major informations with important clinical consequences. Some semiologic points of the radiographic study of the vertebra are perfectly explained by its specific architecture: a radiolucent lesion is difficult to see whereas a sclerotic one is much more easy to individualize; the sclerotic line of the vertebral endplate must be continuous and any interruption is pathologic; the corners of the vertebra must be sharp; the foramen's shape reflects the size of the spinal canal.
Assuntos
Coluna Vertebral/diagnóstico por imagem , Fenômenos Biomecânicos , Humanos , Disco Intervertebral/diagnóstico por imagem , Instabilidade Articular/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Osteólise/diagnóstico por imagem , Complicações Pós-Operatórias , Equilíbrio Postural/fisiologia , Postura/fisiologia , Intensificação de Imagem Radiográfica/métodos , Amplitude de Movimento Articular/fisiologia , Canal Medular/diagnóstico por imagem , Compressão da Medula Espinal/diagnóstico por imagem , Doenças da Coluna Vertebral/diagnóstico por imagem , Espondilolistese/diagnóstico por imagemRESUMO
The main views and indications in adult foot and ankle radiography are detailed. Among foot and ankle diseases, mechanical ones are most frequent, including usual podologic changes (commonly followed by peculiar involvement of certain bones, ligaments, joints, tendons and other soft tissues), synostoses, occult and stress fractures, sprains, and tendon changes. Although they are less frequently encountered in common clinical practice, the radiographic appearance of inflammatory, infectious, and tumoral diseases of foot and ankle are disclosed as well. The correlation existing between some subtle radiographic changes and their counterpart on US, CT, or MR examinations are also emphasized.
Assuntos
Articulação do Tornozelo/diagnóstico por imagem , Ossos do Pé/diagnóstico por imagem , Adulto , Traumatismos do Tornozelo/diagnóstico por imagem , Artrite/diagnóstico por imagem , Artrite Reumatoide/diagnóstico por imagem , Doenças Ósseas/diagnóstico por imagem , Complicações do Diabetes/diagnóstico por imagem , Ossos do Pé/lesões , Fraturas Ósseas/diagnóstico por imagem , Fraturas Fechadas/diagnóstico por imagem , Fraturas de Estresse/diagnóstico por imagem , Humanos , Artropatias/diagnóstico por imagem , Radiografia , Entorses e Distensões/diagnóstico por imagem , Sinostose/diagnóstico por imagem , Sinovite/diagnóstico por imagem , Tendinopatia/diagnóstico por imagem , Traumatismos dos Tendões/diagnóstico por imagem , Tendões/diagnóstico por imagemRESUMO
PURPOSE: For some, cleavage tears remain a pitfall of sonography (US). The purpose of this study is to demonstrate the visibility of intratendinous tears of the supraspinatus and infraspinatus tendons and describe their imaging features on tissue harmonic US. MATERIALS AND METHODS: Prospective study of 52 patients with suspected cuff pathology who underwent US prior to CT-arthrography, CT-bursography or MR arthrography. The US examinations were performed using 7-15 MHz transducers with tissue harmonic mode (pulse subtraction). An intratendinous tear was suggested by the presence of a hypoechoic intratendinous line, extending from a partial or full thickness tear. Results from US were correlated to contrast material enhanced CT or MR findings. RESULTS: Ten cases of cleavage tears were detected on US compared to 18 on arthrographic examinations. False negative results occurred in poor US candidates (n=4), excessively retracted tendons (n=2) or postsurgical cuffs (n=2). Sensitivity was 55% and specificity was 94%, with PPV of 83% and NPV of 80% for the detection of intratendinous tear. The accuracy of US was lower for intratendinous tear associated with full thickness tears (5/11) compared to intratendinous tears associated with partial thickness tears (5/6). CONCLUSION: We demonstrate that cleavage tears are now visible on US using high-frequency transducers and tissue harmonic mode. However, the sensitivity remains too low, especially in patients with full thickness tear, postsurgical patients and patients that are poor candidates to US.
Assuntos
Lesões do Manguito Rotador , Manguito Rotador/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Estudos Prospectivos , Tomografia Computadorizada por Raios X , Ultrassonografia , Ferimentos e Lesões/diagnósticoRESUMO
PURPOSE: To describe osseous, chondral and tendinous lesions associated with fissures of the posterior labrum. To better understand the pathological processes leading to fissure of the posterior labrum. Materials and methods. Retrospective study of 43 CT arthrograms performed in 43 patients that showed a fissure of the posterior labrum. The following associated lesions were noted: osseous and chondral remodeling of the humeral head and/or glenoid and articular surface fissures of the rotator cuff. Based on type of associated lesions, patients were separated into one of four pathological subgroups: posterior instability, posterosuperior or internal impingement, anterior instability and isolated fissure of the posterior labrum. RESULTS: Sixteen patients (37.2%) of patients showed posterior instability, 12 (27.9%) showed lesions of internal impingement, and 11 (25.6%) showed lesions of anterior instability. Only 4 patients (9.3%) had an isolated fissure of the posterior labrum. CONCLUSION: Posterior instability, internal impingement and anterior instability are the main pathologies leading to fissure of the posterior labrum, which seldom occurs in isolation. Evaluation of these associated lesions allows understanding of the underlying pathological processes leading to fissure of the posterior labrum.
Assuntos
Artrografia , Instabilidade Articular/diagnóstico por imagem , Escápula/lesões , Síndrome de Colisão do Ombro/diagnóstico por imagem , Articulação do Ombro/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Feminino , Humanos , Úmero/lesões , Instabilidade Articular/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Lesões do Manguito Rotador , Escápula/diagnóstico por imagem , Síndrome de Colisão do Ombro/etiologia , Lesões do Ombro , Dor de Ombro/etiologiaRESUMO
Peripheral nerve entrapment syndromes involve the compression of a short segment of a nerve at a specific site, as a result of the vulnerability of that nerve as it passes through a fibroosseous tunnel or an opening in fibrous or muscular tissue. Injury of the nerve may occur as a result of compression by the overlying structures. Another mechanism of injury is traction of the nerve, with or without friction of the nerve, as it travels and sharply changes direction around critical points. Imaging can be particularly helpful for the diagnosis of these uncommon injuries. Percutaneous decompression of a ganglion cyst or perineural injection for therapeutic purposes with the aid of fluoroscopy, CT, or ultrasound guidance can be performed in specific areas.
Assuntos
Traumatismos em Atletas/diagnóstico , Síndromes de Compressão Nervosa/diagnóstico , Adulto , Artrografia , Traumatismos em Atletas/diagnóstico por imagem , Síndrome do Túnel Carpal/diagnóstico , Síndrome do Túnel Carpal/diagnóstico por imagem , Criança , Síndrome do Túnel Ulnar/diagnóstico , Diagnóstico Diferencial , Fluoroscopia , Doenças do Pé/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Síndromes de Compressão Nervosa/diagnóstico por imagem , Neuroma/diagnóstico , Síndrome do Túnel do Tarso/diagnóstico , Tomografia Computadorizada por Raios X , Síndromes de Compressão do Nervo Ulnar/diagnóstico , Síndromes de Compressão do Nervo Ulnar/diagnóstico por imagem , UltrassonografiaRESUMO
Wrist imaging is currently used for diagnosis of sport injuries as part of a global strategy of rapid recovery. Standard x-rays are the first step in this procedure. Although arthrography is still the reference for the diagnosis of intrinsic ligament and cartilaginous lesions, MRI can sometimes be sufficient. Ultrasonography is a dynamic process and is accurate in detecting tendon injuries. Wrist sport injuries are frequent and often asymptomatic. Here we review the usual aspects of bone, ligament, and tendon lesions encountered in each sport, while providing advice on the most appropriate imaging for each clinical symptom.
Assuntos
Traumatismos em Atletas/diagnóstico , Fraturas Ósseas/diagnóstico , Traumatismos dos Tendões/diagnóstico , Traumatismos do Punho/diagnóstico , Adulto , Artrografia , Traumatismos em Atletas/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Fraturas Ósseas/diagnóstico por imagem , Golfe/lesões , Humanos , Ligamentos Articulares/lesões , Imageamento por Ressonância Magnética , Masculino , Osteonecrose/diagnóstico , Cisto Sinovial/diagnóstico , Cisto Sinovial/diagnóstico por imagem , Tendinopatia/diagnóstico , Tendinopatia/diagnóstico por imagem , Traumatismos dos Tendões/diagnóstico por imagem , Tênis/lesões , Tenossinovite/diagnóstico , Tenossinovite/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Ultrassonografia , Traumatismos do Punho/diagnóstico por imagemAssuntos
Neoplasias Femorais/diagnóstico , Hemangioma/diagnóstico , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Adulto , Biópsia , Diagnóstico Diferencial , Células Epitelioides/patologia , Feminino , Neoplasias Femorais/patologia , Neoplasias Femorais/cirurgia , Fêmur/patologia , Fêmur/cirurgia , Hemangioma/patologia , Hemangioma/cirurgia , Humanos , Neovascularização Patológica/diagnóstico , Neovascularização Patológica/patologiaRESUMO
PURPOSE: Tears involving the myotendinous junction (MTJ) of the infraspinatus (IS) have been recently described on MRI. These occur centrally in the muscle belly, and are not associated with full thickness tears of the distal infraspinatus tendon. They also induce a rapidly progressive fatty infiltration of the muscles and amyotrophy. The purpose of this study is to assess the accuracy of ultrasonography in diagnosing MTJ tears of the infraspinatus and to describe the usual ultrasonographic appearance compared with MRI. MATERIALS AND METHODS: Retrospective study of 2403 US examinations of the shoulder (over 5 years). Fifteen patients with a reported suspicion of infraspinatus MTJ tears were included. MRI examination was available in all cases, CT arthrography in 13 cases, and one patient underwent surgical confirmation. RESULTS: All patients were sent for an ultrasound for suspect lesion of the tendons of the rotator cuff, with posterior pain in the infraspinatus fossa. All cases seen on ultrasonography were confirmed on MRI. CT arthrography confirmed the absence of tear of the IS tendon in all cases and did not reveal the MTJ tears. Two signs appeared to us as being of special interest: the "tadpole sign" on longitudinal views, and the "black eye sign" on sagittal views. The proximal retraction of the tendon at the MTJ is the anatomical explanation of both signs. CONCLUSION: Tears at the myotendinous junction of the infraspinatus are rare but can be diagnosed on US examination, provided that the sonographer pays attention to the infraspinatus fossa especially in cases of normality of the distal tendinous cuff.
Assuntos
Lesões do Manguito Rotador , Manguito Rotador/diagnóstico por imagem , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Manguito Rotador/patologia , UltrassonografiaRESUMO
Ultrasound is a useful tool to investigate soft tissue masses in the wrist and hand. In most situations ultrasound helps distinguish between a cyst and a tissue mass. This article provides a simple clinical approach to the use of ultrasound imaging for the diagnosis and preoperative assessment of wrist and hand masses.
Assuntos
Mãos , Neoplasias/diagnóstico por imagem , Idoso , Contratura de Dupuytren/diagnóstico por imagem , Humanos , Masculino , Ultrassonografia , PunhoRESUMO
Periventricular enhancement in adults at MRI is a significant finding since it often indicates the presence of an underlying disease requiring prompt medical attention. From a review of patients with periventricular enhancement, the main imaging features based on the underlying infectious or tumoral etiology will be described. The presented differential diagnosis is based on the immune status of the patient, type of enhancement, and response to a trial therapy. In immunocompromised patients, the main considerations are lymphoma and viral ependymitis. The pattern of enhancement is important. The presence of thin linear enhancement suggests a viral etiology (cytomegalovirus or varicella-zoster virus) that can be confirmed at CSF evaluation whereas the presence of nodular enhancement suggests a diagnosis of primary CNS lymphoma that can be confirmed by the presence of lymphomatous cells in the CSF or, more frequently, at stereotactic surgical biopsy performed after failure of response to anti-toxoplasmosis treatment. The presence of band enhancement is less specific and can be seen with viral, lymphomatous and even tuberculous involvement. In immunocompetent patients, a clinical context of infection will suggest bacterial or tuberculous ventriculitis and the presence of cystic lesions will suggest cysticercosis; in the absence of constitutional symptoms, the presence of nodular enhancement will suggest a tumoral process (lymphoma, ependymoma, germ cell tumor, or metastases). Rarely, linear enhancement will be due to sarcoidosis or Whipple's disease.