Tuberculosis of the patella

 A rare case of tuberculosis of the patella is presented. Diagnostic features include an osteolytic lesion in the patella with flaky sequestrum, associated with typical clinical features. Treatment should be urgent and should include a regimen of surgical debridement along with four antitubercular drugs. Once the joint is involved, the end results become less satisfactory.     

Tuberculosis of the sternum and clavicle: imaging findings in 15 patients

Objective. To describe the imaging findings in sterno-clavicular tubercular involvement. Design and patients. Fifteen patients with pathologically proven tuberculosis of the sternum and clavicle were retrospectively evaluated. Routine radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were used in some or all of the patients. Clinical information and imaging features were evaluated in each case. Results. Eight patients had sterno-clavicular joint (SCJ) involvement, five had isolated sternal involvement and two had isolated clavicular involvement. Seven patients were evaluated with only CT, six with only MRI and two with both. There were eight male and seven female patients, varying in age between 16 and 78 years. Fever, swelling and pain were common presenting symptoms. Two patients were HIV positive. Radiographs were positive in only eight patients. Destruction and signal intensity (SI) changes of the sternum and clavicle, destruction of the cartilage, soft tissue changes representing granulation tissue/abscess, displacement of the adjacent structures (vessels, trachea, etc.) and inflammatory changes in the adjacent structures in the form of cellulitis and myositis were common imaging features. Conclusions. All imaging methods can provide complementary information regarding sterno-clavicular tubercular involvement that is helpful for determination of the therapy. MRI is useful in determining the extent of the lesion, particularly marrow involvement and soft tissue extent. Received: 6 December 1999 Revision requested:18 January 2000 Revision received: 23 February 2000 Accepted: 14 March 2000     

Tuberculosis manifesting as multifocal lytic cortical lesions in the femur

Tuberculosis remains a major international health problem despite advances in radiological diagnosis and antituberculous therapy. Disseminated tuberculous infection affecting a single bone and manifested as multifocal lytic cortical lesions is rare and unusual. We report on a 50-year-old man with multifocal involvement of the femur by tuberculosis and demonstrate positive reaction using tuberculosis-polymerase chain reaction on formalin-fixed, paraffin-embedded histological specimens.     

MRI in chronic recurrent multifocal osteomyelitis

 Objective. To review our experience of chronic recurrent multifocal osteomyelitis (CRMO) and to assess the value of MRI in this rare disease, which mainly affects children and adolescents. Design and patients. Seventeen patients from our departments were reviewed. All underwent conventional radiography and MRI, and most had bone scintigraphy. All had undergone bone biopsy, with microbiological and histopathological examinations, to exclude infectious disease, tumours and tumour-like lesions. Results and conclusion. CRMO affects predominantly the tubular bones of the limbs, followed by the clavicle and the spine. Other locations are rare. Diagnosis is important in avoiding unnecessary diagnostic procedures and to initiate appropriate therapy, and is usually based on a characteristic course and the appearances on radiography. However, CRMO lesions of tubular bones and the spine exhibit quite characteristic MRI features which support the diagnosis, while the appearance of the early clavicular lesion is non-specific. At all sites of CRMO in the skeleton, MRI is valuable in assessing the extent and activity of the lesion. It may exclude pyogenic involvement of the bone and soft tissues and guide effective biopsy.     

Imaging in isolated sacral tuberculosis: a review of 15 cases

Objective. To review imaging studies of isolated involvement of the sacrum due to tuberculosis and determine the role of imaging in the diagnosis and management of these patients. Design and patients. A retrospective analysis of 15 cases of isolated sacral tuberculosis imaged with MR imaging was performed. The CT images were also reviewed where available, and the various lesion characteristics were identified. We also reviewed the medical records in an attempt to determine the impact of the imaging studies on the management of these patients. Results. Fifteen patients (5 male, 10 female) presented with symptoms of 3–15 months’ duration. Chronic localized backache with muscle spasm was the commonest presenting symptom; discharging sinuses with abscess formation was found in six patients, five of whom were children. MR imaging of the sacrum revealed a hypointense marrow signal on T1-weighted images and hyperintense signal on T2-weighted images in 14 of 15 patients, the S2 vertebra being always involved. CT revealed osteolytic changes in the sacrum in all the five patients in whom CT was performed. All patients showed marked clinical improvement within 1 year of anti-tuberculous chemotherapy. Conclusion. Isolated tuberculosis of the sacrum is uncommon but should be suspected in patients presenting with chronic low backache or children with discharging sinuses/abscesses and showing sacral destruction on CT or MR imaging. MR imaging can identify cases and enables early institution of anti- tuberculous chemotherapy. Received: 31 August 1999 Revision requested: 1 November 1999 Revision received: 27 March 2000 Accepted: 14 April 2000     

Sonographic detection, evaluation and aspiration of infected acromioclavicular joints

Objective. To describe the sonographic findings of septic arthritis of the acromioclavicular joint. Design and patients. A retrospective study of five male patients was carried out. Four of the patients were referred because of signs and symptoms suggestive of glenohumeral joint septic arthritis, one for signs and symptoms suggestive of septic arthritis of the acromioclavicular joint. All the acromioclavicular joints were evaluated with ultrasound, aspirated and the aspirate cultured. Results. All patients had normal ultrasound findings of their glenohumeral joints and distended acromioclavicular joints as determined by ultrasound. Ultrasound examination elicited focal tenderness over the acromioclavicular joint. Aspirates of each acromioclavicular joint grew pyogenic organisms. Conclusion. Infection in the acromio-clavicular joint is uncommon, but is seen in increased frequency in immune-compromised patients and intravenous drug users. A normal glenohumeral joint on ultrasound in a patient suspected of having a septic shoulder should prompt careful review of the acromioclavicular joint. Aspiration of the acromioclavicular joint is easily performed under ultrasound guidance. Received: 16 May 2000 Revision requested: 18 July 2000 Revision received: 10 October 2000 Accepted: 27 November 2000     

Tuberculous gluteal abscess without bone involvement

 A cold abscess secondary to tuberculous spondylitis or osteomyelitis is a well-recognized entity. However, a soft tissue tuberculous abscess without bone involvement is rare. We present such a case.     

Discrete synchronous multifocal osteoid osteoma of the humerus

 A 24-year-old patient is described who had a 4-year history of pain in the right upper arm, with distinct night pain, that responded to salicylates. From the findings on conventional radiography, bone scintigraphy and MRI a multifocal osteoid osteoma was suspected, with one focus in the cancellous region of the greater tuberosity and a second cortical focus at the proximal humeral diaphysis. The resection ’’en bloc’’ of both tumors and histological examination confirmed the diagnosis. The patient was painfree after the curative resection of the two osteoid osteomas. Osteoid osteoma is a frequently found benign bone tumor, accounting for approximately 11% of cases. In rare cases a multicentric occurrence has been described. A possible occurrence of more than one osteoid osteoma in a single bone, not verified histologically, has been reported only three times in the literature. In patients with scintigraphic and radiographic findings of two foci, discrete synchronous multifocal osteoid osteomas should be suspected.     

Magnetic resonance imaging of rheumatoid arthritis in metacarpophalangeal joints

Objective. To report the development of high-resolution targeted magnetic-resonance imaging (MRI) techniques (not using injections of contrast media) to investigate and monitor rheumatoid arthritis (RA) in the metacarpophalangeal (MCP) joints. Design and patients. A total of 25 RA patients (age range 30–68 years) with varying degrees of disease severity ranging from early onset through active disease to the burnt-out stage, were imaged. (One patient subsequently underwent surgery and histological data was obtained.) A series of 10 control subjects were also studied – two for each 10-year age range. All the RA subjects were assessed for disease activity using standard clinical criteria and radiography as part of normal procedures. MRI was carried out using a targeted system and novel radiofrequency coil. Images of the MCP were performed at very high resolution with 1.5 mm slice thickness and in-plane resolution 130 μm. Standard gradient-echo (GE) sequences were used for anatomical imaging, multiple-echo GE sequences used to produce effective spin-spin relaxation time (T2*) maps and optimised binomial-pulse presaturation used in conjunction with a GE sequence to generate magnetization-transfer (MT) ratio maps. Results. High-quality high-resolution images of the MCP joints were obtained which highlighted normal anatomy and key features characterising the disease state (e.g. pannus, bone erosions, vascularity). Accurate measurements of T2* and MT with variations of ±4% and ±2% respectively were achieved. In active disease, variations in T2* and MT could be determined throughout areas of pannus, clearly demonstrating the heterogeneity of this erosive tissue. Pannus in MCP joints with active destruction was found to have high values of T2* varying from 25 ms to 40 ms with pockets up to 100 ms, whereas pannus present in chronic destruction, or burnt-out disease, had T2* values ranging from 21 to 29 ms. MT-active tissue was uniformly distributed in burnt-out disease, which was confirmed histologically in one case, compared with a more heterogeneous distribution in active disease. Conclusion. The MRI sequences and targeted system developed allow high-resolution studies of RA disease progression and activity. The data confirm the variable pattern of the disease and, in particular, heterogeneity of pannus. Received: 21 July 1999 Revision requested: 29 September 1999 Revision received: 10 February 2000 Accepted: 14 March 2000     

Multifocal osteogenic sarcoma in Paget’s disease

The most serious complication of Paget’s disease is sarcomatous degeneration of pagetic bone. Multifocal sarcomatous degeneration occurs mainly in polyostotic Paget’s disease. Multifocal Paget’s sarcoma is uncommon and can arise in any site. We report two cases of synchronous multifocal sarcomatous degeneration. The two patients were elderly women (aged 77 and 86 years, respectively) who developed sarcomatous lesions concomitantly, in the first case report in left ilium, left tibia, and first lumbar vertebra and in the second case report in the skull, right ilium, and sacrum. Whether these cases are due to the simultaneous development of several primaries or to metastases from a single primary remains unclear. Received: 3 August 1998 Revision requested: 14 September 1998 Revision received: 6 March 2000 Accepted: 14 March 2000     

Radiation dose by spiral CT and conventional tomography of the sternoclavicular joints and the manubrium sterni

 Objective, design and patients. Conventional frontal tomography of the sternum has to some extent been replaced by spiral computed tomography (CT). The objective of this study was to analyse this change of procedure in terms of dosimetry by measurement of the radiation dose to individual organs using an anthropomorphic Rando Alderson phantom. Results. The total effective radiation dose in examination of the sternoclavicular joints and the manubrium sterni was found to be lower using spiral CT than conventional tomography, the values being 0.6 and 0.8 mSv, respectively. Conclusion. As spiral CT is diagnostically comparable and in some respects superior to tomography, its use is recommended for studies of the sternum.     

Locking of metacarpophalangeal joints in a patient with acromegaly

A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking. Received: 17 May 1999 Revision requested: 28 June 1999 Revision received: 19 July 1999 Accepted: 21 July 1999     

MRI of degenerative bone marrow lesions in experimental osteoarthritis of canine knee joints

 Objective. The objective of this study was to determine the value of MRI in the detection of degenerative bone marrow abnormalities in an animal osteoarthritis model. Design. In 10 dogs with experimentally induced unilateral osteoarthritis of the knee, MRI was performed using two-dimensional spin-echo (2D-SE) and three-dimensional gradient-echo (3D-GE) imaging. Contrast enhanced T1-weighted 2D-SE sequences were also obtained after injection of gadolinium-DTPA. The results were compared with the gross and histopathologic findings and with radiography. Results. Histopathologic specimens revealed 21 osteosclerotic lesions and 5 intraosseous cysts. On 2D-SE images, 24 of 26 lesions were detected, while 21 of 26 lesions were identified on 2D-GE sequences. Radiography, including conventional tomography, demonstrated 9 of 26 lesions. Regardless of the sequence weighting, all osteosclerotic lesions appeared hypointense on MRI. Signal loss in bone sclerosis resulted primarily from the reduction of intact fat marrow, the increased bone density being of secondary importance. Quantitative signal analysis allowed approximate estimation of the grade of sclerosis. On postcontrast images, sclerotic bone remained hypointense, although significant but non-specific enhancement relative to the normal fat marrow was observed. The extent of contrast enhancement did not correlate with the grade of osteosclerosis. All five cysts were readily diagnosed by MRI. Cysts displayed either central or marginal contrast enhancement within their cavities. Conclusions. MRI provides a sensitive method for the diagnosis of osteoarthritic bone abnormalities, allowing their differentiation from most non-degenerative subarticular lesions.     

Sarcoidosis of hands

 We present a case of sarcoidosis with soft tissue masses and associated phalangeal erosive changes. Sarcoidosis of the musculoskeletal system presenting as a soft tissue mass has been described previously but is rare. To our knowledge, the combination of soft tissue masses and phalangeal erosions has never been described.     

Vertebral arch or posterior spinal tuberculosis

 Posterior spinal tuberculosis or arch tuberculosis is a form of skeletal tuberculosis that selectively involves the vertebral arch. It may mimic skeletal neoplasm clinically and radiographically. Although posterior spinal tuberculosis has been reported in developing countries it has rarely been found in the United States. As a result, there is limited information about this entity in the US literature. We are presenting our experience in a patient born in the United States.     

MR imaging and CT in osteoarthritis of the lumbar facet joints

Objective. To test the agreement between MR imaging and CT in the assessment of osteoarthritis of the lumbar facet joints, and thus to provide data about the need for an additional CT scan in the presence of an MR examination. Design and patients. Using a four-point scale, two musculoskeletal radiologists independently graded the severity of osteoarthritis of 308 lumbar facet joints on axial T2-weighted and on sagittal T1- and T2-weighted turbo-spin-echo images and separately on the corresponding axial CT scans. Kappa statistics and percentage agreement were calculated. Results. The weighted kappa coefficients for MR imaging versus CT were 0.61 and 0.49 for readers 1 and 2, respectively. The weighted kappa coefficients for interobserver agreement were 0.41 for MR imaging and 0.60 for CT, respectively. There was agreement within one grade between MR and CT images in 95% of cases for reader 1, and in 97% of cases for reader 2. Conclusion. With regard to osteoarthritis of the lumbar facet joints there is moderate to good agreement between MR imaging and CT. When differences of one grade are disregarded agreement is even excellent. Therefore, in the presence of an MR examination CT is not required for the assessment of facet joint degeneration. Received: 12 June 1998 Revision requested: 20 October 1998 Revision received: 29 December 1998 Accepted: 14 January 1999     

Myxoma of the mandible

 Myxoma of the jaw bone is a peculiar and rare tumor. A case of myxoma of the mandible is described in a 38-year-old man. The plain X-ray showed multiple osteolytic destructive lesions in the molar root area. CT scans demonstrated osteolytic expansile lesions with mild enhancement of the solid portion of the mass. Histologically, the tumor is composed of plump stellate cells with abundant amorphous myxoid stroma.     

Extraskeletal mesenchymal chondrosarcoma of the rectus sheath

 Mesenchymal chondrosarcomas (MSCs) are a rare form of chondrosarcoma which usually arise in bone. Extraskeletal chondro-sarcomas constitute a minority (14–25%) of MSCs. We describe the imaging features of an extraskeletal mesenchymal chondrosarcoma that arose from the rectus abdominus muscle.     

活动性肺结核的CT诊断

进一步了解活动性肺结核的ＣＴ表现及其临床应用价值。材料和方法：回顾分析经病理和临床证实的３２例活动性肺结核ＣＴ表现,并与２０例非活动性肺结核作对照。结果：人２８例活动性肺结核发生在上叶尖后段、下叶背段;有２０例呈 不规则斑片状影,边界不清,密度不均;１４例可见病灶钙化,其中９例发生在狭窄或阻塞支气管的增厚管壁上;１１例在实变影中见多发性小空洞;病灶周围有支气管播散者１５例;８例见纵隔淋巴结肿大,其