CT in pyogenic osteomyelitis of the spine

Six patients with bacteriologically proven pyogenic osteomyelitis of the spine were followed serially with computed tomography (CT). Initial evaluation of the involved vertebral bodies and adjacent soft tissues showed a drop in CT numbers when compared to normal cancellous bone and soft tissues. A soft-tissue mass was seen in all cases. After appropriate antibiotic therapy, all six patients showed an increase in bone density and a diminution of the soft-tissue mass (p less than 0.05). Five of the six patients showed a further decrease in soft-tissue CT numbers.     

Computed tomography of osteogenic sarcoma of nasal cavity and paranasal sinuses

Computed tomography was performed in four patients with osteogenic sarcoma of the nasal cavity and paranasal sinuses. In all cases CT demonstrated an abnormal soft tissue mass with associated aggressive bony destruction. In only one case were areas of calcification and new bone formation identified, allowing a preoperative diagnosis. The CT appearance of these four patients plus an additional four cases previously reported in the literature are reviewed.     

MR imaging characteristics in primary lymphoma of bone with emphasis on non-aggressive appearance

Purpose To assess the heterogeneity of magnetic resonance (MR) imaging characteristics in primary lymphoma of bone (PLB), in particular the non-aggressive appearance. Subjects and methods In a retrospective study, MR imaging features were analyzed in 29 patients with histologically proven PLB. The following parameters were evaluated: tumor size, bone marrow and extension into soft tissues, signal characteristics of bone marrow and soft-tissue components, including enhancement, and involvement of cortical bone (complete disruption, focal destruction, permeative destruction and cortical thickening). Results PLB presented with extension into the soft tissue in 22 (76%) of 29 patients, was only subtle in three of these 22 patients, and was absent in seven patients. Signal intensity (SI) of the soft-tissue part was most frequently homogeneously isointense with muscle on T1-weighted images (90%) and high on T2-weighted images (91%). Enhancement was predominantly homogeneous and diffuse (82%). In 93% of patients cortical bone appeared abnormal: among those patients complete cortical disruption was seen in 28%, with extension into soft tissues in all but one patient; a permeative pattern of destruction was present in 52% of patients, 66% of these had an associated soft-tissue mass. Two patients with normal-appearing cortical bone had no extension into soft tissues. In two patients focal cortical destruction was noticed; in one patient cortical bone was homogeneously thickened, and in one patient PLB was selectively localized within the cortical bone. SI of the bone marrow tumor component was more frequently heterogeneous (in 54%), compared with the soft-tissue component, being high on T2-weighted images in 89%, intermediate in 7% and low in 4%. Similarly, enhancement was heterogeneous in 59%. Conclusion The MR imaging appearance of PLB is variable. In 31% of PLB patients, the tumor was intra-osseous, with linear cortical signal abnormalities or even normal-appearing or thickened cortical bone without soft-tissue mass, and, as such, PLB may not infrequently look non-aggressive on MR imaging.     

Static bone cavity of the mandible: Computed tomography findings with histopathologic correlation

PURPOSE: To review computed tomography (CT) findings of histopathologically examined static bone cavities in order to determine whether an additional pathogenesis may play a role in this disease. MATERIAL AND METHODS: Four patients with histopathologically examined static bone cavities were included in this retrospective study. Location, appearance of bone remodeling, tissue characteristics, and contrast enhancement of the cavity were assessed on CT images. CT findings were then compared with the histopathological findings. RESULTS: Static bone cavity was found in the lingual molar region in three patients and in the lingual cuspid region of the mandible in one patient. Both fatty and soft tissues were present in the cavities of all four patients. Attenuation of the soft tissue in the cavities was found to be different from that of the submandibular gland. The soft tissue showed enhancement with contrast-enhanced CT in three patients. For all patients, the histopathologic content of the static bone cavity included fat, soft tissue, and abnormal vasculature. The thickened vein wall in the abnormal vasculature was observed. Aberrant tissue of the submandibular gland was not found in any of the static bone cavities. CONCLUSION: Contrast enhancement of the soft tissue on the contrast-enhanced CT images suggests the presence of vasculature in the cavities. Histopathological examination confirmed the presence of fatty tissue and dilated abnormal vessels, and the absence of salivary gland tissue in the cavities. These findings show that vascular structures are prominent in tissues found in static bone cavities.     

神经性关节病X线征象的再探讨（附11例报告）

目的研究神经性关节病的X线征象。方法临床证实的11例神经性关节病（夏科关节）均经X线平片检查。结果研究证实，骨质吸收、骨膜反应、骨质增生、异位钙化或骨化、软组织肿胀、关节脱位等为本病的典型X线征象。结论骨膜的密度、形态及异位钙化或骨化的部位、形态均能在一定程度上反映本病的病理特征，是X线分型及临床分期的重要参考依据。     

MR imaging of tumor and tumorlike lesions of bone and soft tissue

This review examines the role of MR imaging in the diagnosis and staging of tumors and tumorlike lesions of bone and soft tissue. For tumors of bone, the plain radiograph is not only the least expensive diagnostic test but is the most reliable predictor of the histologic nature of a given lesion. Consequently, it should be the first procedure performed and serve as the basis for determining the next step in the patient's evaluation. MR imaging is the examination of choice for staging bone tumors. CT is preferred to MR imaging only when the characteristics of the lesion are inadequately defined on plain radiographs, as may occur in flat bones. Although MR imaging is of limited value in predicting the histology of bone tumors, it is a useful tool for distinguishing round-cell tumors and metastases from stress fractures and medullary infarcts in symptomatic patients with normal radiographs. For depiction of soft-tissue masses, MR imaging is unrivaled. The histologic nature of a soft-tissue mass may, in some instances, be predicted on the basis of its MR appearance and multicentricity. Biopsy of bone and soft-tissue tumors should follow and not precede MR imaging. MR imaging reliably shows change in tumor volume after radiation or chemotherapy. It is less reliable in predicting the amount of tumor necrosis.     

Imaging of chest wall disorders.

Pathologic processes that may involve the chest wall include congenital and developmental anomalies, inflammatory and infectious diseases, and soft-tissue and bone tumors. Many of these processes have characteristic radiologic appearances that allow definitive diagnosis. Sternal deformities can be visualized at radiography and their severity quantified with computed tomography (CT). In cervical rib, CT with multiplanar reconstruction may demonstrate relevant anatomic detail and the relationship between bone deformity and arterial compression. In Poland syndrome, radiography reveals an area of hyperlucency on the affected side, whereas CT demonstrates the absence of the greater pectoral muscle and clearly depicts associated musculoskeletal anomalies. Tuberculosis typically manifests at radiography and CT as osseous and cartilaginous destruction and soft-tissue masses with calcification and rim enhancement. Aspergillosis involving the chest wall manifests as pulmonary consolidations and permeative osteolytic changes of the rib and spine at CT and as an area of increased signal intensity at T2-weighted magnetic resonance (MR) imaging. Neurogenic tumors and hemangiomas also typically have high signal intensity at T2-weighted MR imaging. Apparent mass extension or unequivocal bone destruction seen at CT or MR imaging may indicate chest wall involvement by lymphoma. Radiologically, soft-tissue sarcomas typically appear as areas of soft-tissue density or attenuation, often associated with necrotic areas of low density or attenuation. At radiography, plasmacytoma typically manifests as well-defined, "punched-out" lytic lesions with associated extrapleural soft-tissue masses. Chondrosarcoma frequently appears as a large, lobulated excrescent mass arising from a rib with scattered flocculent calcifications characteristic of its cartilaginous mix. Familiarity with these radiologic features facilitates accurate diagnosis and optimal patient treatment.     

Elastofibroma: MR and CT appearance with radiologic-pathologic correlation.

OBJECTIVE. The purpose of our study was to determine the MR and CT appearances of elastofibroma and correlate the imaging features with the underlying pathologic findings. MATERIALS AND METHODS. We reviewed retrospectively the MR and CT findings in five cases of elastofibroma. All patients had a soft-tissue mass; one patient also complained of pain. The mean age of the patients was 71 years (range, 63-79 years). Four lesions occurred in the subscapular region, and one occurred in the thigh. In addition, we reviewed and compared the demographic data of 72 histologically proved cases for which we had archival data. RESULTS. Three of four lesions evaluated with spin-echo MR imaging were approximately isointense with skeletal muscle and contained areas with a signal intensity similar to that of fat; these corresponded to areas of dense collagen and interspersed fat, respectively. In the fourth case, the MR appearance was nonspecific. In one case, MR imaging with gadopentetate dimeglumine showed areas with and without enhancement. Three of four lesions evaluated with CT had variable margins, with tissue attenuation similar to that of the adjacent soft tissue as well as scattered areas of decreased attenuation, suggesting fat within the lesion. In one case, the lesion was well defined and relatively homogeneous with an attenuation less than that of skeletal muscle. CONCLUSION. The MR and CT features of elastofibroma are different from those of most other soft-tissue tumors, reflecting entrapped fat within a predominantly fibrous mass. Although these features are not pathognomonic, their presence in a subscapular lesion in an older patient suggests a presumptive diagnosis of elastofibroma.     

Computed tomography of malignant lymphoma involving the skull

The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.     

Periantral soft-tissue infiltration and its relevance to the early detection of invasive fungal sinusitis: CT and MR findings.

PURPOSEOur goal was to illustrate the relevance of periantral soft-tissue infiltration to the early diagnosis of invasive fungal sinusitis and to describe variations in the appearance of normal periantral soft tissues.METHODSWe reviewed two cases of pathologically proved invasive maxillary fungal sinusitis in which the sole imaging finding suggestive of invasive disease was periantral soft-tissue infiltration. Variations in the CT appearance of normal periantral soft tissues were studied in 112 patients by assessing the appearance of the fat planes along the anterior and posterior bony antral walls and by noting the presence of infraorbital and distal internal maxillary artery branch vessels within the anterior and posterior periantral fat planes, respectively.RESULTSNone of the 112 patients had findings that suggested, or that could mimic, soft-tissue infiltration in the anterior periantral soft tissues. In only one (1%) of the 112 patients was there a loss of visibility of the posterior periantral fat plane that was not clearly attributable to the otherwise normal-appearing posterior periantral soft tissues.CONCLUSIONInfiltration of the periantral fat planes may represent the earliest imaging evidence of invasive fungal disease. When encountered as the sole radiologic finding, periantral soft-tissue infiltration should suggest the possibility of invasive fungal sinusitis in the appropriate clinical setting.     

局限性骨化性肌炎的X线、CT表现

目的：探讨局限性骨化性肌炎的X线平片和CT表现,提高影像诊断水平。方法：回顾性分析19例经病理或随访证实局限性骨化性肌炎患者的X线、CT表现,其中19例均行X线平片检查,13例行CT检查。结果：X线表现为软组织内条片状或分层状骨化影;CT表现：早期（急性水肿期）局部肌肉水肿,无明确骨化成分,受累骨可出现轻微骨膜增生,中期（增殖肿块期）表现为分层状＂蛋壳＂样骨化,病灶中心呈软组织密度,晚期（骨化修复期）病灶局限,边界清楚,周围肌肉水肿消失,影像学表现为离心性分布的骨化团块。结论：局限性骨化性肌炎早期影像学表现缺乏特征性,容易误诊,中晚期分层状＂蛋壳＂样骨化对本病诊断有重要价值。     

艾滋病并发软组织骨骼感染的X线和CT表现

目的 探讨艾滋病(AIDS)并发软组织骨骼感染的X线和CT表现.方法 回顾性分析18例AIDS并发软组织骨骼感染的X线和CT表现.结果 18例AIDS并发软组织骨骼感染中,蜂窝织炎1例,CT表现为皮下斑片状密度增高影.软组织脓肿6例,CT表现为类圆形低密度灶,增强后呈环状强化.脓性肌炎1例,CT表现为不均匀低密度灶,增强后病灶边缘强化.脓毒性关节炎4例,其中膝关节病变3例,髋关节病变1例;X线平片示骨质破坏2例,正常2例;CT表现为骨质破坏3例,关节腔积液4例.骨髓炎9例,其中骨结核8例,包括椎体病变6例,X线和CT的主要表现为椎体骨质破坏,骨质增生,死骨形成,椎间隙变窄;肋骨病变3例,CT表现为膨胀性骨质破坏;髂骨、骶骼关节病变1例,X线和CT表现为骨质破坏,死骨形成,关节间隙增宽.股骨慢性化脓性骨髓炎1例,X线表现为骨质破坏,骨质增生硬化,骨膜反应.结论 软组织和骨骼感染是艾滋病常见并发症,影像检查对疾病的早期诊断和治疗具有重要意义.     

Use of MR imaging to assess results of chemotherapy for Ewing sarcoma

MR imaging was used to monitor the results of initial chemotherapy of primary Ewing sarcoma of bone. The signal intensities of the soft-tissue and marrow components of the tumor were evaluated on T2-weighted images obtained in 10 patients (nine with responsive tumors) at presentation and during and immediately after completion of two cycles of chemotherapy. MR evidence of marrow and soft-tissue involvement was seen in all tumors at presentation. After treatment, the bone-marrow component of the nine drug-sensitive tumors showed an increase in signal intensity that in eight cases became comparable to that of water. Changes in signal intensity of the soft-tissue component were variable, consisting of increases in two of the responsive lesions, no change in three, a decrease in two, and complete resolution of the soft-tissue mass in two. There was no increase in signal intensity of either the bone-marrow or the soft-tissue component of the single nonresponsive tumor. All of the responsive tumors showed advanced healing, and abundant bony sclerosis was apparent on CT. Bone-marrow examinations, performed in seven of the nine patients with responsive lesions, disclosed no evidence of tumor in four. Two patients had residual extramedullary tumor; the nonresponsive lesion contained sheets of tumor cells. The increase in marrow signal intensity on T2-weighted images was associated with replacement of marrow elements by a loose, hypocellular myxoid matrix containing modest amounts of collagen, consistent with response to chemotherapy and eradication of disease. Therefore, an increase in the T2-weighted signal intensity of the bone-marrow component of Ewing sarcoma of bone reflected a favorable response to chemotherapy. MR signal changes, however, were not predictive of resolution of malignant disease within adjacent soft tissue.     

CT窗口技术在诊断恶性骨肿瘤的应用

目的 研究不同窗宽窗位在恶性骨肿瘤诊断中的价值。材料与方法 分别在骨窗、软组织窗及中间窗下,对28例经手术病理证实的恶性骨肿瘤患者的CT表现进行回顾性统计学分析,比较不同窗口条件下CT对恶性骨肿瘤的诊断率。结果 骨窗能明确反映骨肿瘤骨密度异常的区域,而软组织窗及中间窗对显示肿瘤周围软组织和骨皮质受侵犯以及水肿等更敏感。结果 窗口技术对骨肿瘤的定性和分期具有重要的诊断价值。     

原发性与继发性动脉瘤样骨囊肿CT表现

目的评价CT对诊断与鉴别原发性与继发性动脉瘤样骨囊肿的价值。方法回顾性分析9例经手术病理证实原发性与继发性动脉瘤样骨囊肿的CT征象,并进行献复习。结果9例患中骨皮质缺损征象出现率(67％)高于“液一液平面”出现率(44％)。继发性动脉瘤样骨囊肿骨嵴明显粗大,可构成分房。9例病灶内呈不均匀软组织密度,增强后强化明显。结论CT检查有助于动脉瘤样骨囊肿早期定性诊断,并有助于鉴别原发性与继发性病灶。     

The diabetic foot: initial experience with 18F-FDG PET/CT.

Osteomyelitis complicates up to one third of diabetic foot infections, is often due to direct contamination from a soft-tissue lesion, and represents a clinical challenge. Early diagnosis is important since antibiotic therapy can be curative and may prevent amputation. The present study assessed the role of PET/CT using 18F-FDG for the diagnosis of diabetic foot osteomyelitis. METHODS: Fourteen diabetic patients (10 men and 4 women; age range, 29-70 y) with 18 clinically suspected sites of infection underwent PET/CT after the injection of 185-370 MBq of 18F-FDG for suspected osteomyelitis complicating diabetic foot disease. PET, CT, and hybrid images were independently evaluated for the diagnosis and localization of an infectious process. Additional data provided by PET/CT for localization of infection in the bone or soft tissues were recorded. The final diagnosis was based on histopathologic findings and bacteriologic assays obtained at surgery or at clinical and imaging follow-up. RESULTS: PET detected 14 foci of increased 18F-FDG uptake suspected as infection in 10 patients. PET/CT correctly localized 8 foci in 4 patients to bone, indicating osteomyelitis. PET/CT correctly excluded osteomyelitis in 5 foci in 5 patients, with the abnormal 18F-FDG uptake limited to infected soft tissues only. One site of mildly increased focal 18F-FDG uptake was localized by PET/CT to diabetic osteoarthropathy changes demonstrated on CT. Four patients showed no abnormally increased 18F-FDG uptake and no further evidence of an infectious process on clinical and imaging follow-up. CONCLUSION: 18F-FDG PET can be used for diagnosis of diabetes-related infection. The precise anatomic localization of increased 18F-FDG uptake provided by PET/CT enables accurate differentiation between osteomyelitis and soft-tissue infection.     

Primary malignant lymphoma of the maxillary sinus: CT and MRI

We reviewed the CT and MRI of seven patients with primary malignant lymphoma of the maxillary sinus to find if there are characteristic imaging findings suggestive of the disease. The images were analysed for appearance, size, signal, internal characteristics, extent of tumour, bone change and lymph node enlargement. In two patients, the tumour first presented with mucosal thickening. In the remaining five, the tumours were an expansile mass 4–6 cm in diameter at the time of detection. Although it was difficult to distinguish tumour from mucosa or obstructed fluid on CT, T2-weighted MRI enabled us to separate tumour from normal mucosa or fluid. In two patients, the tumours were heterogeneous. Calcification and haemorrhage were observed in one patient. Periantral soft-tissue infiltration was always present, even when tumour appeared as slight mucosal thickening. Posterior extension was seen in all patients. Permeative and lytic bone destruction accompanied most cases of periantral soft-tissue infiltration; mixed destruction and sclerosis was also observed. Mucosal thickening with periantral soft-tissue infiltration may suggest malignant lymphoma of the maxillary sinus in its early form. Various types of bone change may accompany the periantral soft-tissue infiltration. Received: 25 January 1999 Accepted: 21 July 1999     

Radiation-induced sarcoma of bone: CT findings in 19 cases

We reviewed the CT findings in 19 cases of radiation-induced sarcoma of bone. The latent period before development of the sarcoma ranged from 5 to 50 years (mean, 17 years). In all 19 lesions, a soft-tissue extraosseous component was seen on CT, and 18 of them had associated bone destruction. Expansion of the affected bone and tumor-matrix mineralization each were present in 10 patients, but occurred together in only five patients. Periosteal reaction was seen in five patients, one of whom had an associated fracture. Radiation osteitis could not be identified on CT scans in the affected bone of any of the patients when tumor was present, but it was present in contiguous bone in two patients and had been shown 6 years before tumor became apparent in the affected bone in one other patient. Radiation-induced sarcoma of bone should be considered when bone destruction and an associated soft-tissue mass are shown on CT, or when changes occur in the appearance of previously stable irradiated bone.     

Osteoid osteoma: MR imaging revisited

To assess and compare with computed tomography (CT) the performance of magnetic resonance (MR) imaging in the detection of osteoid osteoma, and determine the features of this lesion on MR imaging. The prospective MR imaging and CT diagnosis of osteoid osteoma was determined from original radiology reports. MR images were assessed retrospectively with regard to the location and signal intensity of the nidus and surrounding bone marrow and soft tissue edema. These findings were correlated with the age of the patient, duration of symptoms, and drug therapy. Ten patients with histologically proven osteoid osteoma who underwent MR imaging were reviewed. All 10 lesions were correctly diagnosed at the time of MR imaging. None of the lesions was intracortical. Nine lesions were intra-articular. Two out of five patients with extracortical lesions had false negative CT preceding the MR study. Signal intensity of the nidus, marrow, and soft tissue edema on MR imaging were variable. Perinidal edema was most pronounced in younger patients and had no apparent relation to drug therapy. MR imaging reliably demonstrates the nidus of an osteoid osteoma, which has a variable appearance related to its position relative to the cortex of the bone. A predominance of cancellous osteoid osteomas are encountered in patients referred for MR imaging. Marrow edema in the vicinity of the lesion improves the conspicuity of the nidus. CT may fail to diagnose osteoid osteoma when the nidus is in a cancellous location, due to the lack of perinidal density alteration.     

Angiosarcoma epitelioide óseo multifocal con metástasis pulmonares

Angiosarcoma is a rare mesenchymal neoplasm that may arise from vascular or lymphatic tissue. Bone primary angiosarcoma is extremely rare, representing less than 1% of all angiosarcomas. It́s a very aggressive neoplasm and patients have metastatic disease at initial diagnosis in a large percentage of cases. On radiographs, these lesions are usually aggressive osteolytic lesions, commonly with soft-tissue mass extension, and tumoral enhancement on CT or MR imaging. The appearance of the bone scan is variable, describing studies with tracer uptake or low uptake. These tumours are more often found in the long bones, but spinal involvement has been reported in 10% of patients.There are a few reports in the literature of bone angiosarcoma with lung metastases.We present a patient with multifocal epithelioid angiosarcoma (spine and ribs) and multiple lung metastasis, evidenced by CT and conventional bone scintigraphy, with a fast growth.