Tuberculous arthritis of the appendicular skeleton: MR imaging appearances

Tuberculosis [TB] of the appendicular skeleton is an uncommon infection caused by the tuberculous bacilli and constitutes only 1-3% of all tuberculosis infections. MR imaging features of tuberculous arthritis include bone marrow oedema, cortical erosions, synovitis, joint effusion, tenosynovitis, soft tissue collections, and myositis. These imaging features are at times non-specific, but in the correct clinical context help in diagnosis of tuberculosis. We present the various pathological manifestations of TB arthritis involving the different joints of appendicular skeleton and discuss their MR imaging appearances.     

MRI of musculoskeletal extraspinal tuberculosis

PURPOSE: The aim of this study was to describe the MR findings in extraspinal musculoskeletal tuberculosis (EMT). METHOD: A retrospective review was conducted of the MR findings of 18 patients with microbiologically and/or pathologically proven EMT. All MR studies were performed using T1-and T2-weighted spin echo sequences. T1-weighted spin echo sequences after Gd-DTPA injection were obtained for 12 patients. The MR images were evaluated for abnormalities in joints, bones, and soft tissues, and the results were grouped by anatomic localization, frequency distribution of structures affected, and morphologic patterns of involvement. RESULTS: Isolated soft tissue tuberculosis was found in 10 (55.5%) patients and involvement of more than one structure in 8 (44.4%). Pyomyositis (n = 6) and arthritis with involvement of adjacent soft tissues (n = 7) were the most common forms of presentation. One patient presented with isolated fascial superficial tissue involvement in one leg. Isolated pyomyositis involving one (n = 3) or two (n = 3) muscles was homogeneous in six cases and showed intermediate (n = 6), low (n = 2), or high (n = 1) signal intensity on T1-weighted images and a high and very hyperintense signal on T2-weighted images. The tenosynovitis synovial fluid was homogeneous (n = 1) or heterogeneous with multiple tiny hypointense nodules (n = 1) on T2-weighted images. The subdeltoid bursitis fluid was characterized by homogeneous low signal intensity with a hyperintense rim (n = 2) on T1-weighted images and homogeneous (n = 1) or heterogeneous hyperintense signals with areas of low signal intensity (n = 1) on T2-weighted images. In tuberculous arthritis, the synovial joint fluid (n = 7) showed heterogeneous (n = 4) or homogeneous (n = 3) low signal intensity on T1-weighted images and high or very high signal intensity on T2-weighted images. Where involved, the adjacent muscle(s) (n = 8) were usually hypointense on T1-weighted images and very hyperintense on T2-weighted images. Associated cellulitis was found in arthritis with involvement of neighboring soft tissues (n = 5), pyomyositis (n = 2), and tenosynovitis (n = 1). The images obtained after Gd-DTPA showed peripheral (n = 10) or heterogeneous (n = 1) enhancement or no enhancement (n = 1). CONCLUSION: The MR findings for EMT are variable. Although diagnosis is dependent largely on prior presumption and clinical context, MRI provides valuable guidelines in defining the extent of the lesions to select the appropriate treatment and for follow-up of abnormalities.     

Imaging findings of complications affecting the upper extremity in intravenous drug users: featured cases

Infections generally occur in intravenous drug abuse (IVDA) patients, most commonly affecting the spine and proximal joints. Numerous serious musculoskeletal complications of IVDA may involve the upper extremity, however. Soft-tissue complications in the upper extremity of IVDA patients include cellulitis, ulceration, abscess, pyomyositis, septic bursitis, tenosynovitis, and necrotizing fasciitis. Foreign bodies in soft tissue due to needle fragments are common findings. Primary bone and joint IVDA complications include osteomyelitis (acute and chronic) and septic arthritis. Other IVDA complications in the upper extremity affecting blood vessels and lymphatics include hematoma, arterial aneurysm and pseudoaneurysm, thrombosis, thrombophlebitis, "puffy hand" syndrome, and lymphadenopathy. These complications usually present as urgent issues requiring prompt and accurate evaluation in the acute setting. Diagnostic imaging not only aids in making the correct diagnosis but also permits precise definition of the location and extent of these abnormalities. We review the imaging findings and illustrate a wide range of disabling and even life-threatening complications affecting the upper extremity of IVDA patients that require early diagnosis for optimal outcome.     

Imaging features of musculoskeletal tuberculosis

The purpose of this article is to review the imaging characteristics of musculoskeletal tuberculosis. Skeletal tuberculosis represents one-third of all cases of tuberculosis occurring in extrapulmonary sites. Hematogenous spread from a distant focus elsewhere in the body is the cornerstone in the understanding of imaging features of musculoskeletal tuberculosis. The most common presentations are tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue involvement. The diagnostic value of the different imaging techniques, which include conventional radiography, CT, and MR imaging, are emphasized. Whereas conventional radiography is the mainstay in the diagnosis of tuberculous arthritis and osteomyelitis, MR imaging may detect associated bone marrow and soft tissue abnormalities. MR imaging is generally accepted as the imaging modality of choice for diagnosis, demonstration of the extent of the disease of tuberculous spondylitis, and soft tissue tuberculosis. Moreover, it may be very helpful in the differential diagnosis with pyogenic spondylodiscitis, as it may easily demonstrate anterior corner destruction, the relative preservation of the intervertebral disk, multilevel involvement with or without skip lesions, and a large soft tissue abscess, as these are all arguments in favor of a tuberculous spondylitis. On the other hand, CT is still superior in the demonstration of calcifications, which are found in chronic tuberculous abscesses.     

Primary multifocal tuberculous osteomyelitis with involvement of the ribs

Two cases of primary multifocal tuberculous osteomyelitis with involvement of the rib cage are presented. The lungs were normal and the appearance of the skeletal lesions did not suggest tuberculosis. These lesions were predominantly lytic, with minimal soft tissue involvement. Tuberculosis should be high in the differential diagnosis of multiple destructive bone lesions, especially in patients from regions where tuberculosis is endemic.     

Distinguishing stress fractures from pathologic fractures: a multimodality approach

Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount.     

MRI of tuberculous pyomyositis.

PURPOSE: The purpose of this article is to describe the findings of MRI in tuberculous pyomyositis (PM). METHOD: The MR images of four proven cases of tuberculous PM were retrospectively reviewed and analyzed with clinical and laboratory findings. The location, signal intensity on T1- and T2-weighted spin echo images, presence of abscess, signal intensity of peripheral rim, patterns of contrast enhancement, and associated findings were evaluated. RESULTS: On MR images, all cases demonstrated low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in a single muscle. Abscess was seen in all cases. Peripheral rim showed subtle hyperintensity on T1-weighted images and hypointensity on T2-weighted images. After gadolinium infusion, peripheral rim enhancement was observed in all cases. Cellulitis was associated in one case. The patients clinically presented with a palpable mass of long duration. CONCLUSION: Tuberculous PM shows characteristic findings of a well demarcated abscess with rim enhancement at MRI and can be distinguished from other soft tissue masses.     

Magnetic resonance imaging of bone and soft tissue tumors: Early experience in 31 patients compared with computed tomography

In 31 patients with 21 soft tissue and 10 bone tumors, magnetic resonance imaging (MRI) and computed tomography (CT) were equally effective in delineating the margins of most soft tissue tumors, and the margins of bone tumors from fat and adjacent normal bone. However, MRI was superior to CT in delineating bone tumors from adjacent muscle, and in showing the relationships to bone of the deep margins of some soft tissue tumors. This was true because the quality of CT images around thick cortical bone often was severely degraded by streak artifact, which does not occur in MRI.Excellent anatomic detail was achieved on MRI by spin echo pulse sequences with short repetition times. Bone tumors were delineated best by spin echo 1000/30 images, and soft tissue tumors by spin echo 1000/30 or inversion recovery images.     

Imaging of tuberculous disease involving breast

The aim of our study was to evaluate radiologic findings of the tuberculosis involving breast. We evaluated the radiologic features of 17 patients (18 lesions) with tuberculous disease involving the breast. The radiologic examinations, including mammography (16 patients), ultrasonography (12 patients), and Gd-DTPA-enhanced dynamic MRI (6 patients), were analyzed. Mammographic findings included mass (12 of 17 lesions), calcification (3 of 17 lesions), asymmetric density with spiculated margin (5 of 17 lesions), and axillary lymph node enlargement (8 of 17 lesions). On ultrasonography, a smooth bordered mass (7 of 13 lesions) with thin boundary (7 of 13 lesions) and heterogeneous, intermediate internal echoes (9 of 13 lesions) were most commonly demonstrated. On Gd-DTPA-enhanced dynamic MRI, 3 lesions showed significant enhancement at the first minute after injection (3 of 7 lesions). The maximun enhancing amount was greater than 500 normalized units, and the enhancing pattern was smooth or irregular ring appearance. Breast involvement with tuberculosis is rare but should be considered in the differential diagnosis of a woman living in an endemic area or when extramammary foci of tuberculosis are present. A multimodality imaging approach with clinical evaluation will help to establish the diagnosis of tuberculosis involving breast. Received 26 May 1997: Revision received 4 September 1997; Accepted 19 January 1998     

Tuberculous tenosynovitis of the wrist: MRI findings in three patients

 We report recent MRI findings in patients with tuberculous tenosynovitis of the wrist. Marked synovial thickening around the flexor tendons and fluid in the tendon sheath were clearly shown on MRI. Post-contrast study was useful in distinguishing the thick tenosynovium from the surrounding structures and fluid in the tendon sheath. The well-enhanced tenosynovium was also seen in the carpal tunnel in all cases. On the basis of these findings, we could easily distinguish tenosynovitis from other soft-tissue-mass lesions, such as tumors or infected ganglia. Tuberculous tenosynovitis is often not diagnosed early, and its differentiation from soft tissue tumors may be clinically difficult. MRI, particularly post-contrast study, is useful for early diagnosis of, and planning treatment for, tuberculous tenosynovitis.     

恶性纤维组织细胞瘤的影像学诊断

目的探讨原发性恶性纤维组织细胞瘤影像学特征。材料和方法回顾性分析5例原发性恶性纤维组织细胞瘤的X线、CT或MRI影像表现特点。结果5例均经病理证实,分别发生于小腿软组织、胫骨干及腰椎各1例,髂骨2例。原发于骨者影像学主要表现为骨质破坏、软组织肿胀或巨大肿块、患骨膨胀,骨膜反应少见,病损部位可见钙化。发生于软组织者表现为非特异性肿块,邻近骨正常或受累。结论原发性恶性纤维组织细胞瘤的X线、CT或MRI均有特征性表现,CT或MRI在确定肿瘤侵犯范围与软组织肿块方面明显优于X线。     

Tuberculous bicipitoradial bursitis: A case report

An 76-year-old man with an indolent soft tissue mass on the volar aspect of the left elbow was referred to our institution with a diagnosis of a soft tissue tumor. He had a history of lung tuberculosis since the age of 30. The mass was adjacent to the biceps brachi tendon. It demonstrated homogeneous low-signal intensity on T1-weighted magnetic resonance (MR) images and heterogeneous relatively high signal intensity with scattered low and high signal intensity areas on T2-weighted MR images. An excision was performed after needle biopsy with presumptive diagnosis of bicipitoradial bursitis. The histological specimen revealed an epithelioid cell granuloma with central necrosis. While the occurrence of tuberculous bicipitoradial bursitis has never been reported, this case demonstrates that it can be considered to be among the causes of a cystic lesion around the elbow joint.     

成软骨细胞瘤的MRI表现特点

目的 分析成软骨细胞瘤的MRI表现特点.方法 对经病理证实的20例成软骨细胞瘤的MRI信号特点、病灶形态和生长方式,以及周围骨髓和软组织有无水肿、有无骨膜反应、相邻关节有无积液等征象进行分析.结果 20例病灶在T1WI和T2WI上表现为不均质的混杂信号,病灶形态为分叶状;16例病灶呈膨胀性生长;18例病灶周围出现骨髓水肿;14例病灶周围软组织水肿;6例病灶周围有骨膜反廊;7例病灶突破骨皮质向周围突出;6例棚邻的关节有关节积液.结论 成软骨细胞瘤在MRI上多表现为分叶状和膨胀性生长,病变呈不均质混杂信号,病灶周围有明显的骨髓水肿和邻近软组织水肿.     

化脓性脊椎炎与结核性脊椎炎的MRI鉴别

目的:提高化脓性脊椎炎(PS)与结核性脊椎炎(TBS)的MRI鉴别诊断水平。方法:收集经手术/局部病灶穿刺活检病理证实或临床随访证实的20例化脓性脊椎炎和30例结核性脊椎炎,比较其MRI表现,用χ2检验进行统计学分析。结果:以下MRI表现PS与TBS之间具有显著性差异(P<0.05):胸椎受累(PS为14.3%,TBS为56.9%);腰椎受累(68.6%,33.8%);病变椎体破坏变形(0,56.7%);椎旁软组织受累(30%,70%);椎旁脓肿形成(0,70%);韧带下蔓延(20%,63.3%);T2WI高信号(35%,70%)。结论:MRI检查能够为PS与TBS的鉴别提供可靠信息。     

The Morel-Lavallée lesion: pathophysiology,clinical presentation,imaging features,and treatment options

Morel-Lavallée lesions are posttraumatic hemolymphatic collections related to shearing injury and disruption of interfascial planes between subcutaneous soft tissue and muscle. We review the pathophysiology of Morel-Lavallée lesions, clinical presentation, and potential sites of involvement. Magnetic resonance imaging (MRI) is the modality of choice for characterization. We present the MRI classification and highlight the key imaging features that distinguish the different types, focusing on the three most common: seroma, subacute hematoma, and chronic organizing hematoma. Potential mimics of Morel-Lavallée lesions, such as soft tissue sarcoma and hemorrhagic prepatellar bursitis, are compared and contrasted. Treatment options and a management algorithm are also briefly discussed.     

MR imaging features of foot involvement in patients with psoriasis

OBJECTIVE: To determine alterations of the soft tissues, tendons, cartilage, joint spaces, and bones of the foot using magnetic resonance (MR) imaging in patients with psoriasis. MATERIALS AND METHODS: Clinical and MR examination of the foot was performed in 26 consecutive patients (52ft) with psoriasis. As a control group, 10 healthy volunteers (20ft) were also studied. Joint effusion/synovitis, retrocalcaneal bursitis, retroachilles bursitis, Achilles tendonitis, soft-tissue edema, para-articular enthesophytes, bone marrow edema, sinus tarsi syndrome, enthesopathy at the Achilles attachment and at the plantar fascia attachment, plantar fasciitis, tenosynovitis, subchondral cysts, and bone erosions, joint space narrowing, subchondral signal changes, osteolysis, luxation, and sub-luxation were examined. RESULTS: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in none of the patients while frequency of involvement was 92% (24/26) by MR imaging. The most common MR imaging findings were Achilles tendonitis (acute and peritendinitis) (57%), retrocalcaneal bursitis (50%), joint effusion/synovitis (46%), soft-tissue edema (46%), and para-articular enthesophytes (38%). The most commonly involved anatomical region was the hindfoot (73%). CONCLUSION: Our data showed that the incidence of foot involvement was very high in asymptomatic patients with psoriasis on MR imaging. Further MR studies are needed to confirm these data. We conclude that MR imaging may be of importance especially in early diagnosis and treatment of inflammatory changes in the foot.     

MR imaging of tuberculous vertebral osteomyelitis: pictorial review

Vertebral osteomyelitis is one of the most common manifestations of tuberculosis. Magnetic resonance imaging is considered the main imaging modality for the diagnosis, the demonstration of the extent of the disease, and follow-up studies. Vertebral destruction involving two consecutive levels with sparing of the intervertebral disc, disc herniation into the vertebral body, epidural involvement, and paraspinal abscess are the most common MRI findings suggestive of tuberculous vertebral osteomyelitis. Received: 28 April 2000 Revised: 17 July 2000 Accepted: 19 July 2000     

椎间盘炎与脊椎结核的MRI鉴别诊断

目的:探讨椎间盘炎与脊柱结核在MRI上的不同点,从而达到鉴别的目的。方法:20例为经手术后或椎间盘穿刺术后临床证实的椎间盘炎,20例为临床证实的脊柱结核。结果:椎间盘炎与脊柱结核在MRI上的不同点表现在:①临床表现上:椎间盘炎疼痛症状明显,而椎体结核早期可无任何临床症状;②椎间盘改变上:早期椎间盘炎以T2WI加权像髓核内低信号裂隙征消失为明显,椎间盘变狭为后期表现,而椎体结核中后期椎间盘才会有改变;③相邻椎体骨质改变上:椎间盘炎表现为相邻的上、下两个椎体的部分或全部对称性炎性改变,少有椎体骨折,而椎体结核椎体骨质多呈虫蚀样破坏,常侵蚀多个椎体,常合并病理性骨折;④椎旁软组织改变上:椎体结核远比椎间盘炎明显,椎体结核常侵犯到腰大肌、椎管内硬膜外间隙及一侧椎间孔,常使椎管狭窄,而椎间盘炎仅表现为椎间盘旁软组织的轻度肿胀。结论:椎间盘炎与脊柱结核各有其特点,仔细观察椎间盘、椎体以及椎旁软组织上的改变,结合临床已不难鉴别。     

MR features of tuberculous osteomyelitis

OBJECTIVE: To describe the MR imaging features of tuberculous osteomyelitis. DESIGN AND PATIENTS: MR imaging features of 11 patients (14-65 years) with proven extra-spinal tuberculous osteomyelitis were reviewed. Osseous and adjacent soft-tissue changes were analyzed. RESULTS: On the basis of the signal intensity characteristics compared with the normal marrow fat, two kinds of lesions were observed: (a) predominantly intermediate to low signal intensity lesions on T2-weighted images with low signal intensity on T1-weighted images, and (b) lesions which had a discrete peripheral zone of marginally higher signal intensity than the center on T1-weighted images and surrounding edema and lower signal intensity than the fatty bone marrow with variable signal intensity on T2-weighted images. Soft-tissue abscesses and marrow edema were each noted in eight cases. Soft-tissue edema was noted in most cases. CONCLUSION: An osseous lesion with intermediate to low signal intensity on T2-weighted images and associated soft-tissue abscess may be suggestive of tuberculous osteomyelitis. Lesions with a rim of mildly increased signal intensity on T1-weighted images, a non-specific indicator of an infective process, may also be seen.