Epithelioid hemangioma of bone

Although no specific radiographic appearance has emerged to date for the epithelioid subtype of hemangioma, these lesions most typically exhibit well-defined osteolysis. Other relatively common features include surrounding sclerosis, cortical expansion and cortical destruction. We present a case of epithelioid hemangioma of the spine with an unusual radiological appearance which to our knowledge has not previously been reported: diffuse sclerosis of the involved vertebral body. The diffuse sclerosis seen in this case resembles the osteosclerotic process seen not only in benign entities such as subacute and chronic osteomyelitis, but also in malignant lesions such as osteoblastic metastatic disease and lymphoma. Received: 28 July 2000 Revision requested: 8 September 2000 Revision received: 5 December 2000 Accepted: 6 December 2000     

Case report: Malignant fibrous histiocytoma complicating chronic osteomyelitis

Sarcomas occurring in relation to draining sinuses and foci of chronic osteomyelitis are rare. We report a case of malignant fibrous histiocytoma (MFH) as a complication of chronic osteomyelitis. This highly malignant sarcoma has not previously been reported in this condition.     

Osteogenic sarcoma (report of 18 cases)

Eighteen cases of osteogenic sarcoma of the long bones in the extremities were analyzed in this paper. The pathological basis of the X-ray signs was explained. It was suggested that solitary calcific shadow appearing near the knee joint in young individuals should alert the radiologist to the possibility of osteogenic sarcoma. The X-ray findings of osteogenic sarcoma were characterized by dissociation of osteolysis from ossification. Simultaneous bony destruction both inside and outside the cortex was one of the patterns of erosive bone destruction in osteogenic sarcoma. The distinction between benign and malignant bony spicules, the differences in the relationship between soft tissue mass and subcutaneous fat layer and that between osteomyelitis and the subcutaneous fat layer were discussed.     

肋骨肿瘤和肿瘤样病变

本文报告经手术和病理证实的肋骨肿瘤和肿瘤样病变７２例，其中良性病变５１例，恶性２１例、良性病变以骨纤维异常增殖症和软骨源性肿瘤多见，恶性肿瘤以转移瘤和骨髓瘤多见。本文提出了良恶性肿瘤鉴别要点和有助于某些肿瘤诊断的Ｘ线表现的特点，还报告了几例少见表现为中度膨胀性破坏的转移瘤。少数肋骨慢性骨髓炎易与肿瘤混淆。     

Exclusion of chronic osteomyelitis with F-18 fluorodeoxyglucose positron emission tomographic imaging

PURPOSE: Excluding the diagnosis of chronic osteomyelitis is often difficult with noninvasive techniques, especially when bone anatomy and structure have been altered by trauma, surgery, or soft-tissue infection. It has been reported that fluorodeoxyglucose (FDG) positron emission tomography (PET) has excellent potential to diagnose osteomyelitis. In this study, the accuracy of FDG PET in the diagnosis of chronic osteomyelitis was determined. METHOD: Twenty-two patients with possible osteomyelitis (5 in the tibia, 5 in the spine, 4 in the proximal femur, 4 in the pelvis, 2 in the maxilla, and 2 in the feet) who underwent FDG PET imaging and on whom operative or clinical follow-up data were available were included in this analysis. The final diagnosis was made by surgical exploration or clinical follow-up during a 1-year period. RESULTS: FDG PET correctly diagnosed the presence or absence of chronic osteomyelitis in 20 of 22 patients. Six had chronic osteomyelitis and 16 proved to be free of osteomyelitis. FDG PET correctly identified all six patients with chronic osteomyelitis but produced two false-positive results. This study had a sensitivity rate of 100%, a specificity rate of 87.5%, and an accuracy rate of 90.9%. CONCLUSION: FDG PET is a highly effective imaging method to exclude osteomyelitis when a negative scan result is obtained. However, positive results can be caused not only by true osteomyelitis but also by inflammation in the bone or surrounding soft tissues as a result of other causes. Overall, FDG PET may prove to be the preferred study in the management of patients with possible chronic osteomyelitis.     

慢性难治性骨髓炎动物模型制备与鉴定

目的探讨慢性难治性骨髓炎动物模型制备与鉴定的实验方法。方法根据文献方法制备兔的慢性骨髓炎模型,模型确定后,给予尽可能彻底的清创及敏感抗生素治疗2 w,再观察临床表现、大体观、X线表现以及行骨髓组织细菌培养、组织学观察,最后以组织学观察为基础,确定慢性难治性骨髓炎模型的建立。结果 10只局部出现软组织肿块,20只动物X线片提示局部软组织肿胀影、骨质增生、低密度空洞影;25只骨髓组织细菌培养阳性,21只组织学观察呈慢性炎症改变。结论 21只实验动物慢性难治性骨髓炎模型制备成功,证实此法可成功制备慢性难治性骨髓炎动物模型,成功率为56.8%。     

Severe metallosis following total knee arthroplasty: a case report and review of radiographic signs

Metallosis is an uncommon complication following total knee arthroplasty that leads to osteolysis and implant loosening due to chronic inflammatory reaction. Abrasion between the metallic surfaces of the implant releases metallic debris that interacts with the periprosthetic soft tissues and causes chronic synovitis. Here we present a case of a 65-year-old man who had undergone total knee arthroplasty 10 years ago and developed implant loosening associated with severe metallosis and varus instability. Radiographs show the three typical signs of metallosis: metal-line sign, bubble sign, and cloud sign. This patient was subjected to revision surgery consisting of debridement and primary implant replacement by a hinged endoprosthesis. Knowledge of the typical radiographic and clinical findings of metallosis is important to rapidly diagnose this complication and avoid progressive joint destruction.     

Pseudo-sarcomatous osteomyilitis in the child (author's transl)]

The authors report three unusual cases of paediatric osteomyelitis resembling a lytic or mixed osteosarcoma. The severity of the radiological lesions is such that only a diagnostic approach is possible before surgical biopsy. Under the effects of treatment, osteolysis resolved in two cases by bone eburnation in two cases and pandiaphyseal sequestration in one case. These three cases were collected in less than a year. Thus osteomyelitis is currently adding new diagnostic traps in bone pathology in children.     

Applications of fluorodeoxyglucose-PET imaging in the detection of infection and inflammation and other benign disorders

FDG-PET has great potential in the evaluation of a variety of inflammatory and infectious disorders and possibly other benign disorders. FDG-PET is very helpful in the evaluation of chronic osteomyelitis, sarcoidosis, FUO, and differentiating toxoplasmosis from lymphoma in the central nervous system in HIV-positive patients. The assessment of efficacy of FDG-PET in the evaluation of arthroplasty-associated infection, large-vessel vasculitis, and other inflammatory and infectious disorders is ongoing but seems quite promising at this time.     

Imaging of the diabetic foot

Destruction in diabetic feet is secondary to neuropathy (peripheral and autonomic nervous system) in association with microangiopathy. The loss of sensation to pain and the static trouble lead to increase the pressure in some areas and predispose to pedal skin ulceration, the precursor of osteomyelitis. Plain radiography should be the first step in the evaluation for diagnosis and follow-up. The initial patterns are nonspecific but very rapid evolution associating osteolysis, osteosclerosis and fragmentation lead to the Charcot foot. When osteomyelitis is suspected, scintigraphy with labelled white blood cells and MRI are necessary to differentiate infection from neuropathy.     

Fluorine-18 fluorodeoxyglucose PET in infectious bone diseases: results of histologically confirmed cases

The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake.     

Osteomyelitis originating in and around bone infarcts: giant sequestrum phenomena

OBJECTIVE: We describe four cases of osteomyelitis that occurred in and around foci of preexisting osteonecrosis in the medullary cavity. Although sequestration is a well-known complication of osteomyelitis, there is little information known about infection occurring in proximity to large regions of already necrotic bone. CONCLUSION: Osteomyelitis and bone infarction can be seen in the same patient population. Medullary infarcts may function as sequestra, predisposing patients to osteomyelitis and soft-tissue infection.     

Chronische Infektionen des Skelettsystems Bildgebende Diagnostik

The diagnosis of chronic osteomyelitis is made on the basis of clinical, radiologic and histologic findings. The role of imaging in patients with known chronic osteomyelitis is to detect and to delineate areas of active infection. To correctly interpret the imaging findings, it is essential to take both the individual clinical findings and previous imaging studies into account. Reliable signs of active infection are bone marrow abscess, sequestra and sinus tract formation. Only the combined evaluation of bony changes together with alterations of the adjacent soft tissues provides good diagnostic accuracy. Projection radiography gives an overview of the condition of the bone, which provides the basis for follow-up and the selection of further imaging modalities. Computed tomography can be used to evaluate even discrete or complex bony alterations and to guide percutaneous biopsy or drainage. Magnetic resonance imaging achieves the best diagnostic sensitivity and specificity and provides superior contrast as well as anatomical resolution in both bone marrow and soft tissues. In this paper the features and clinical relevance of imaging in primary chronic osteomyelitis, posttraumatic osteomyelitis, tuberculous spondylitis and osteomyelitis of the diabetic foot are reviewed, with particular respect to MRI.     

CT appearance of nidus in osteoid osteoma versus sequestration in osteomyelitis

Osteoid osteoma is a benign osteoblastic tumor usually diagnosed by conventional radiography. Computed tomography can be used preoperatively to localize the nidus and avoid unnecessary or misdirected resection. In this report CT appearance of the nidus in osteoid osteoma versus sequestration in osteomyelitis is presented.     

Fluorine-18 fluorodeoxyglucose positron emission tomography in infectious bone diseases: results of histologically confirmed cases

The aim of this study was to evaluate the clinical use of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in acute and chronic osteomyelitis and inflammatory spondylitis. The study population comprised 21 patients suspected of having acute or chronic osteomyelitis or inflammatory spondylitis. Fifteen of these patients subsequently underwent surgery. FDG-PET results were correlated with histopathological findings. The remaining six patients, who underwent conservative therapy, were excluded from any further evaluation due to the lack of histopathological data. The histopathological findings revealed osteomyelitis or inflammatory spondylitis in all 15 patients: seven patients had acute osteomyelitis and eight patients had chronic osteomyelitis or inflammatory spondylitis. FDG-PET yielded 15 true-positive results. The tracer uptake correlated with the histopathological findings in each case. Bone scintigraphy performed in 11 patients yielded ten true-positive results and one false-negative result. Follow-up carried out on two patients revealed normal or clearly reduced tracer uptake, which correlated with a normalisation of clinical data. In early postoperative follow-up it was impossible to differentiate between postsurgical reactive changes and further infection using FDG-PET. It is concluded that acute and chronic osteomyelitis of the peripheral as well as the central skeleton can be detected using FDG-PET. Osteomyelitis can be differentiated from soft tissue infection surrounding the bone. Unlike computed tomography and magnetic resonance imaging, FDG-PET is not affected by metal implants used for fixing fractures. FDG-PET demonstrated promising initial results with respect to treatment monitoring. Nevertheless, in the early postoperative phase FDG-PET seems to be of limited value owing to unspecific tracer uptake. Received 4 November 1999 and in revised form 20 January 2000     

Central skull base osteomyelitis as a complication of necrotizing otitis externa: Imaging findings, complications, and challenges of diagnosis

Central skull base osteomyelitis is a rare, life-threatening complication of necrotizing or "malignant" otitis externa (NOE), which results in destruction of the skull base. The imaging appearances can be misinterpreted as malignancy but consideration of this diagnosis, both radiologically and clinically, is imperative to avoid the need for biopsy. The aim of this review is to highlight the pertinent imaging findings on computed tomography and magnetic resonance imaging as well as the potential complications of this condition.     

Acute osteomyelitis as a complication of varicella

Varicella is a common viral infection in childhood, and acute osteomyelitis is one of the rare but serious complications. We report two cases of osteomyelitis as a complication of varicella. The possibilities and limitations of the different imaging modalities are discussed, as well as imaging findings during the course of this condition.     

Osteomyelitis of the sacrum

In the axial skeleton, osteomyelitis of the os sacrum is rare, although it occurs more frequently than tuberculosis of the sacrum. Secondary osteomyelitis as a complication of tumours, metastases or inflammatory processes of the adjacent areas is seen more often than primary sacral osteomyelitis.     

Multifocal osteomyelitis in childhood. Review by radionuclide bone scan.

Multifocal osteomyelitis is considered an uncommon complication of acute osteomyelitis. Over a 3-year period, 136 infants and children who had a final diagnosis of acute osteomyelitis were reviewed, and multifocal osteomyelitis was detected in 27 (19%) patients. The major age peak of acute osteomyelitis was between 6 weeks and 3 years (46%). Two age peaks were found for multifocal disease-less than 6 weeks (38%), and 9 to 12 years (44%). Three patients with multifocal disease had septicemia and photon-deficient areas on bone scans. Another adolescent group had nonspecific bone and joint pain that in some cases persisted for more than 3 months and were finally diagnosed as multifocal osteomyelitis. Organisms were isolated in 15/27 (56%). Multifocal osteomyelitis is well recognized in the neonatel age group. However, it occurs more commonly than previously described in older patients. This higher incidence can most likely be attributed to the higher use of the radionuclide bone scan early in the disease and the high sensitivity of the scan for the detection of osteomyelitis.     

Skeletal photopenic lesions in In-111 WBC imaging

Four cases of skeletal photon-deficient areas in In-111 white blood cell (In-111 WBC) images are reported. These were found in patients with lymphoma, vertebral osteomyelitis, and following radiotherapy and extensive surgical procedures. We emphasize that these photopenic lesions, although uncommon, may represent tumor involvement or benign processes, including osteomyelitis. Possible mechanisms to explain this phenomenon are discussed.