Neck neoplasms: MR imaging. Part I. Initial evaluation

Untreated neoplasms of the neck (tumors of the oropharynx, supraglottic area, carotid body, and thyroid, in addition to malignant lymphadenopathy) were evaluated in 23 patients with magnetic resonance (MR) imaging. The results were compared with computed tomographic (CT) scans in 20 patients. Contrast between tumor and fat was best on relatively T1-weighted images (500/30-35 [TR msec/TE msec]), whereas separation of tumor and muscle was best with relatively T2-weighted pulse sequences (1,500/90). Balanced images (1,500/30-35) provided best overall image quality and best demonstrated vascular anatomy. MR imaging was usually superior to CT in showing the relationship of tumor mass to muscle. MR imaging and contrast material-enhanced CT were equivalent in most patients in defining vascular anatomy, but MR imaging was superior when intravenous contrast material was not administered. However, CT was more helpful in showing bone and cartilage anatomy, and in some patients CT also was better in showing airway abnormalities. Despite these limitations, MR imaging is a promising imaging technique for studying neoplasms of the neck.     

Advanced imaging of melorheostosis with emphasis on MRI

Objective: To describe the CT and MR imaging appearance of both osseous and extraosseous manifestations of melorheostosis. Design and patients: We retrospectively reviewed the CT (n=7) and/or MR imaging findings (n=12) of 17 patients with characteristic radiographic findings of melorheostosis (undulating cortical hyperostosis with marked uptake on radionuclide bone scintigraphy). Results: CT and MR imaging revealed cortical hyperostosis as high attenuation and low signal intensity on all MR pulse sequences, respectively. Encroachment on the marrow space was seen in all cases resulting from endosteal involvement. Thirteen patients demonstrated 14 soft tissue masses with infiltrative margins in 80% of cases and seven showed extensive mineralization on CT or MR imaging (low intensity on all pulse sequences). Seven soft tissue masses were predominantly nonmineralized with intermediate signal intensity on T1-weighted and intermediate to high signal on T2-weighted MR images corresponding to vascularized fibrous tissue with variable collagen content pathologically. Enhancement after intravenous gadolinium was seen in all patients imaged with soft tissue masses (n=2). Two patients demonstrated muscle atrophy resulting from nerve involvement. Conclusions: The osseous abnormalities in melorheostosis are identical on advanced imaging and radiographs. Mineralized or nonmineralized soft tissue masses should be recognized as another manifestation of this disease as opposed to a more ominous finding, making biopsy unwarrranted. Received: 16 January 2001 Accepted: 21 February 2001     

CT and MR of neurofibromatosis of the bladder.

Neurofibromatosis of the genitourinary system is rare. We present the CT and MR findings of neurofibromas of the bladder in three patients with von Recklinghausen disease (neurofibromatosis, Type 1). In one case, genitourinary involvement was the primary presentation of the disease. Both CT and MR imaging revealed diffuse and nodular bladder wall involvement, along with pelvic sidewall and adjacent soft tissue abnormalities. The CT attenuation coefficients measured near soft tissue density. On T1-weighted spin echo MR images the tumors revealed signal intensity slightly greater than that of skeletal muscle. Neurofibromas showed markedly increased signal intensity on T2-weighted images relative to the surrounding soft tissues, with marked enhancement in two cases imaged following Gd-DTPA administration. Obstructive hydronephrosis was present in all cases, presumably due to neurofibromas involving the trigonal region. Pelvic sidewall tumors were visualized as rounded, nodular masses extending into the obturator foramina. In the evaluation of patients with von Recklinghausen disease, MR imaging, compared with CT, more clearly defined tumor extent within the bladder, pelvic sidewalls, and surrounding soft tissues.     

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.     

Gadolinium-DTPA-Enhanced MR Imaging of Spinal Neoplasms: Preliminary Investigation and Comparison with Unenhanced Spin-Echo and STIR Sequences

Unenhanced T1- and T2-weighted spin-echo, short inversion time inversion recovery (STIR), and gadolinium-DTPA (Gd-DTPA)-enhanced spin-echo and STIR imaging techniques were used in 20 patients as part of a multicenter study to assess the safety and efficacy of Gd-DTPA in spinal imaging. Five patients had normal MR scans. Of those with lesions, both Gd-DTPA-enhanced T1-weighted spin-echo and unenhanced STIR scans improved detection and evaluation of spinal tumors over conventional spin-echo methods, particularly T2-weighted spin echo, by providing higher tissue contrast in shorter imaging times. The Gd-DTPA-enhanced T1-weighted spin-echo scans were most helpful in evaluating intradural tumors, whereas STIR sequences were most effective for extradural tumors and bone metastases. In most cases, Gd-DTPA-enhanced T1-weighted spin-echo scans best delineated tumor margins, and the enhancement was helpful in suggesting a cellular or active nature of the lesions. In some cases, the enhancement resulted in a more homogeneous and thus less abnormal-appearing marrow in vertebrae involved by tumor; therefore, a precontrast T1-weighted spin-echo scan is necessary in all patients who are to be studied with Gd-DTPA.A combined approach that uses T1-weighted spin-echo, Gd-DTPA-enhanced T1-weighted spin-echo, and STIR images currently appears optimal for MR imaging of spinal neoplasms. T2-weighted spin-echo images add information only in occasional cases.     

MR imaging of primary bone and soft tissue tumors

MR imaging of 131 cases with pathologically confirmed primary bone and soft tissue tumors were studied. They included 44 bone tumors (25 benign tumors, 19 malignant tumors) and 87 soft tissue tumors (55 benign tumors, 32 malignant tumors). MR imaging was performed on 0.5T, superconductive magnet system. All tumors were evaluated with T1-weighted, T2-weighted and STIR images. In some cases, contrast enhanced MR imaging with Gd-DTPA was applied. MR imaging was proving to be a valuable technique in the evaluation of patients with primary bone and soft tissue tumors. MR imaging was superior to the other modalities in delineating the extent of the tumor and their relation to surrounding structures in all cases. However, plain radiography and CT were more useful for evaluation of calcification, ossification, cortical destruction and endosteal/periosteal reaction than MR imaging. Direct sagittal and coronal images from MR imaging added accurate assessment for the relation between the tumor and their adjacent structures. MR imaging was of limited value in distinguishing benign from malignant tumors with the demonstration of tumor structures only, especially soft tissue tumors. But in bone and soft tissue tumors which have specific morphologic features and intensity patterns, MR imaging was very useful for diagnosis.     

Gadolinium-DTPA-enhanced MR imaging of spinal neoplasms: preliminary investigation and comparison with unenhanced spin-echo and STIR sequences

Unenhanced T1- and T2-weighted spin-echo, short inversion time inversion recovery (STIR), and gadolinium-DTPA (Gd-DTPA)-enhanced spin-echo and STIR imaging techniques were used in 20 patients as part of a multicenter study to assess the safety and efficacy of Gd-DTPA in spinal imaging. Five patients had normal MR scans. Of those with lesions, both Gd-DTPA-enhanced T1-weighted spin-echo and unenhanced STIR scans improved detection and evaluation of spinal tumors over conventional spin-echo methods, particularly T2-weighted spin echo, by providing higher tissue contrast in shorter imaging times. The Gd-DTPA-enhanced T1-weighted spin-echo scans were most helpful in evaluating intradural tumors, whereas STIR sequences were most effective for extradural tumors and bone metastases. In most cases, Gd-DTPA-enhanced T1-weighted spin-echo scans best delineated tumor margins, and the enhancement was helpful in suggesting a cellular or active nature of the lesions. In some cases, the enhancement resulted in a more homogeneous and thus less abnormal-appearing marrow in vertebrae involved by tumor; therefore, a precontrast T1-weighted spin-echo scan is necessary in all patients who are to be studied with Gd-DTPA. A combined approach that uses T1-weighted spin-echo, Gd-DTPA-enhanced T1-weighted spin-echo, and STIR images currently appears optimal for MR imaging of spinal neoplasms. T2-weighted spin-echo images add information only in occasional cases.     

Longitudinal stress fractures of the tibia: diagnosis by magnetic resonance imaging

 Objective. Previous works describe magnetic resonance (MR) imaging characteristics of stress fractures. Diagnosis of the atypical, longitudinal type of stress fracture has been reported using computed tomography (CT). This report focuses on MR imaging of longitudinal stress fractures of the tibia. Materials and methods. Six cases are presented in which a longitudinal linear abnormal marrow signal was detected in the middle and distal parts of the tibial shaft. Five patients were imaged using a 1.5 Tesla MR unit. Axial, sagittal and coronal T1 and T2-weighted or fat suppressed proton density fast spin echo images were obtained in all but one patient. One patient was imaged using a 0.5 Tesla MR unit with axial and coronal T1- and T2-weighted sequences. Initial conventional radiographs seen at clinical presentation were interpreted as normal in all cases. Two patients underwent radionuclide bone scan, and one patient was imaged with CT prior to MR imaging. Results. In each instance, MR imaging demonstrated linear marrow signal abnormalities orientated along the long axis of the tibial shaft. Endosteal and periosteal callus was identified on axial images. In all cases, MR imaging clearly demonstrated a fracture extending through one cortex with abnormal signal in both the marrow cavity as well as adjacent soft tissues indicating edema. Conclusion. MR imaging was shown to be excellent for demonstration of fracture lines, callus, and marrow and soft tissue abnormalities seen in association with longitudinal stress fractures.     

Bone tumors: magnetic resonance imaging versus computed tomography

The magnetic resonance (MR) imaging characteristics of bone tumors are described and the clinical utility of MR imaging in patient evaluation is reported. Fifty-two patients with skeletal lesions were examined with a Picker MR imager (0.15-T resistive magnet). Twenty-five patients had primary malignancies, seven had benign bone neoplasms, 15 had skeletal metastases, and five had neoplasm simulators. Forty-five patients had CT scans available for comparison. For demonstrating the extent of tumor in marrow, MR was superior to CT in 33% of cases, about equal to CT in 64%, and inferior to CT in 2%. For delineating the extent of tumor in soft tissue, MR was superior to CT in 38% of cases and about equal to CT in 62%. CT was superior in all cases for demonstrating calcific deposits and pathologic fractures. In four patients with metal prostheses or surgical clips, MR was superior to CT in documenting recurrent tumor because of artifactual degradation of the CT image. Direct sagittal and coronal images from MR permit accurate assessment of the relationship of tumor to adjacent normal structures, including the physis, joints, and neurovascular structures. MR is useful in the evaluation of bone tumors: it is of greatest value in evaluations of the peripheral skeleton, the medullary canal, soft tissues, and postoperative tumor recurrence. With a 0.15-T magnet, MR is less useful in the evaluation of the axial skeleton and cortical bone.     

Osteosarcoma. A new diagnostic approach in presurgical loco-regional staging

The value of Magnetic Resonance (MR) imaging was examined in the anatomical staging of bone osteosarcomas. Eleven patients were studied--8 central and 3 parosteal osteosarcomas. The accuracy of MR imaging was compared to that of plain film, scintigraphy, CT, and angiography. MR imaging was superior to both CT and radionuclide scanning in defining intramedullary extension and in showing skip metastases. Cortical erosion in central osteosarcomas was demonstrated by MR imaging, CT, and plain film; in 1 case of parosteal osteosarcoma MR imaging was superior to CT in showing cortical penetration. In two cases MR imaging did not accurately demonstrate the relationship of the tumor to the major vessels; only angiography showed vascular involvement. MR imaging was useful in delineating extraosseous extension. The importance is stressed of a correct use of MR imaging towards an accurate diagnosis. In fact, intramedullary extension and skip metastases were better demonstrated on T1-weighted images with large fields, while T2-weighted images and small fields were needed for the best overall evaluation of extraosseous involvement. In conclusion, MR imaging should be used for preoperative staging of osteosarcomas in those cases where diagnosis was made on the basis of clinical, radiographic, and bioptic findings.     

Mycetoma: comparison of MR imaging with CT

Magnetic resonance (MR) images obtained in 18 patients with pathologically confirmed mycetoma in the body (n = 4) or lower extremity (n = 14) were retrospectively reviewed and compared with computed tomographic (CT) scans in 15 patients and surgical findings in 10. T1-weighted images showed an infiltrating mass (same signal intensity as muscle) involving skin, subcutaneous fat, muscles, tendons, and other tissues. On T2-weighted images, the mass and affected structures showed moderately increased signal intensity. Bone marrow involvement was detected in seven patients and was best visualized on T1-weighted images. CT showed moderate enhancement of the infiltrative process in all patients. Bone changes, seen in nine, included coarse trabeculation, periosteal reaction, endosteal proliferation, and patchy destruction. MR imaging and CT were comparable and correlated well with surgery in showing the extent of soft-tissue involvement. Early bone changes (important for therapy planning for pedal mycetoma) were seen only at CT. The study showed that MR imaging is sensitive for assessing the extent of mycetoma in the soft tissues. CT should be the method of choice for staging pedal lesions because it can be used to detect early bone involvement.     

Primary lung cancer staging: prospective comparative study of MR imaging with CT

Forty-four patients with bronchogenic carcinoma were studied prospectively by both computed tomography (CT) and magnetic resonance (MR) imaging of the thorax during the week preceding thoracotomy. Transaxial MR imaging sequences included T1- and T2-weighted sequences. Coronal and sagittal T1-weighted sequences were added according to tumor location. CT and MR studies were reviewed separately, and the results were compared with surgical and pathologic findings on the basis of TNM classification. No statistically significant differences were found between the two imaging methods for the evaluation of tumor extent or node involvement. T2-weighted sequences did not yield further information on tumor extent or node involvement. Additional imaging planes (coronal or sagittal) appeared useful to study chest wall invasion. Analysis of concordances and discordances did not indicate whether one modality could be substituted for the other, or which diagnostic strategy might be more useful.     

Cross-sectional imaging of primary osseous hemangiopericytoma

The aim of this study was to assess cross-sectional imaging features and the value of CT and MRI in primary hemangiopericytoma of bone. In five patients with histologically proven primary osseous hemangiopericytoma CT and MR scans were evaluated retrospectively. Both CT and MRI were available in four patients each. In three patients both imaging techniques were available. On CT primary hemangiopericytoma of bone presents as an expansive lytic lesion with bone destruction and inhomogeneous contrast enhancement. Magnetic resonance imaging depicts osseous hemangiopericytoma as hyperintense lesion on T2-weighted images with intermediate signal intensity on T1-weighted images. Curvilinear tubular structures of signal void in the tumor matrix on T1-weighted images and corresponding hyperintense structures on T2-weighted and on fat-suppressed short tau inversion recovery images were present in three patients. Although cross-sectional imaging findings are non-specific, they add to the diagnosis and provide valuable information about the extent of bone destruction and local tumor spread in patients with primary osseous hemangiopericytoma. While CT demonstrates the extent of bone destruction best, MRI better visualizes medullary and soft tissue extension of the tumor. Curvilinear signal abnormalities support the diagnosis of hemangiopericytoma of bone. This imaging pattern is best visualized on fat-suppressed or contrast enhanced T1-weighted MR images.     

眶壁转移瘤的CT和MRI诊断

目的分析研究眶壁转移瘤的CT和MRI特点,提高诊断准确率.方法回顾性分析23例经手术病理证实的眶壁转移瘤的CT和MRI表现,成人组16例,儿童组7例.所有病例均行CT平扫与MR平扫和增强扫描.结果16例成年患者CT表现均为溶骨性骨质破坏和眼眶不规则肿块,9例骨质破坏区邻近的颅内可见扁平不规则肿块;16例MRI表现为骨质破坏区邻近的眼眶和颅内均可见略长T1、略长T2信号的不规则软组织影,增强后呈明显强化.7例儿童患者CT表现均为溶骨性骨质破坏和眼眶不规则肿块,其中2例可见垂直针状高密度影,3例骨质破坏区邻近的颅内可见扁平不规则软组织肿块;MRI显示7例骨质破坏区邻近的眼眶内和6例颅内可见略长T1、略长T2信号不规则的软组织影,其中1例为双侧,增强后呈明显强化;7例双侧眶骨、4例斜坡和双侧岩尖及1例双侧颞骨鳞部骨髓腔呈略长T1、略长T2信号影,增强后呈明显强化.结论眶壁转移瘤的CT和MRI表现有一些特点,有助于诊断和鉴别诊断.     

Trans-sphenoidal spread of rhinopharyngeal neoplasms. Correlations between computerized tomography and magnetic resonance

In 1957 Teoh observed, in an autopsic series of 31 patients with nasopharyngeal carcinoma, 3 cases of neoplastic spread through the marrow spaces of the base of the skull, without macroscopic bone alterations. In order to demonstrate in vivo this kind of neoplastic spread, CT and MR examinations of 35 patients with nasopharyngeal carcinoma were reviewed. In 3/26 cases the invasion of the marrow spaces of the clivus was demonstrated. In these cases CT showed only minimal alterations in spongiosa and cortices of the clivus, associated with intracranial soft-tissue tumoral components. MR imaging demonstrated, with great accuracy, the replacement of bone marrow in the clivus by neoplastic tissue of intermediate signal intensity on T1-weighted images. Tumor tissue was characterized by high signal intensity on T2-weighted images. The authors stress the greater utility of MR imaging in evaluating the permeative involvement of the base of the skull.     

MR imaging of edema accompanying benign and malignant bone tumors

To evaluate the incidence, quantity, and presentation of intra- and extraosseous edema accompanying benign and malignant primary bone lesions, the magnetic resonance (MR) studies of 63 consecutive patients with histologically proven primary bone tumors were reviewed. MR scans were assessed for the presence and quantity of marrow and soft tissue edema and correlated with peroperative findings, resected specimens and follow-up data. The signal intensity and enhancement of tumor and edema prior to and after intravenous administration (if any) of gadolinium-labled diethylene triamine pentaacetate (Gd-DTPA) was analyzed. Marrow edema was encountered adjacent to 8 of 39 malignant tumors and 14 of 24 benign lesions. Soft tissue edema was found accompanying 28 of 39 malignancies and 10 of 24 benign disorders. On unenhanced T1-weighted MR images tumor and edema were difficult to differentiate. Tumor inhomogeneity made this differentiation easier on T2-weighted sequences. In 36 patients the contrast medium Gd-DTPA was used. Edema was present in 27 of these patients and the respective enhancement of tumor and edema could be compared. Edema always enhanced homogeneously, and in most cases it enhanced to a similar degree as or more than tumor. Marrow and, more specifically, soft tissue edema is a frequent finding adjacent to primary bone tumors. The mere presence and quantity of marrow and soft tissue edema are unreliable indicators of the biologic potential of a lesion. Unenhanced MR scans cannot always differentiate between tumor and edema, but the administration of Gd-DTPA is of assistance in differentiating tumor from edema. Awareness of marrow and/or soft tissue edema adjacent to bone lesions is of importance because edema can be a pitfall in the diagnostic work-up and staging prior to biopsy or surgery.     

Value of dynamic MR imaging in assessing endometrial carcinoma involvement of the cervix

OBJECTIVE: The purpose of this study was to evaluate endometrial carcinoma involvement of the cervix using dynamic MR imaging compared with T2-weighted and contrast-enhanced T1-weighted MR imaging. SUBJECTS AND METHODS: In 42 patients with endometrial carcinoma, T2-weighted MR imaging using rapid acquisition with relaxation enhancement, dynamic MR imaging using gradient-echo sequences, and contrast-enhanced T1-weighted MR imaging using spin-echo sequences were performed before treatment. We evaluated patterns of enhancement in the cervix and tumor. In 39 of the 42 patients who underwent surgical treatment, we compared MR imaging findings with histologic results concerning cervical involvement. RESULTS: Enhancement of the cervical epithelium was greater than that of the tumor and cervical stroma on dynamic MR imaging in most patients. In assessing cervical involvement, the accuracy of T2-weighted, dynamic, and contrast-enhanced T1-weighted MR imaging was 85%, 95%, and 90%, respectively; no statistically significant difference was observed. False-positive cases on T2-weighted MR imaging were correctly identified as having no cervical involvement on dynamic MR imaging using the finding of continuous enhancement of the cervical epithelium. We found this finding to be reliable in assessing tumor involvement of the cervix. CONCLUSION: We believe that, in combination with T2-weighted MR imaging sequences, dynamic MR imaging is useful in assessing endometrial carcinoma involvement of the cervix.     

Osteomyelitis in children: gadolinium-enhanced MR imaging.

Fifteen pediatric patients with biopsy- or culture-proved nonspinal osteomyelitis were studied with magnetic resonance (MR) imaging. Osteomyelitis was acute in seven patients, subacute in three, and chronic in five. Four patients had subperiosteal abscesses, one had a large associated soft-tissue abscess, and one had an intraosseous (Brodie) abscess. Areas of active inflammation had decreased marrow signal intensity on T1-weighted images, increased signal intensity on T2-weighted images, and enhancement on T1-weighted images obtained after gadopentetate dimeglumine administration (n = 10). Abscesses were rim enhancing (n = 3) or not (n = 2) with gadolinium-enhanced MR imaging. Nonenhancing areas presumably represented necrotic material. Gadolinium-enhanced MR imaging assisted in definition of the presence and extent of nonvascularized fluid collections within the bone and/or adjacent soft tissues and the extent of bone involvement in patients with chronic osteomyelitis. It also helped guide surgical debridement of intraosseous disease (n = 7) and open or percutaneous drainage of subperiosteal or soft-tissue fluid collections (n = 5).     

Intracranial solitary fibrous tumors: imaging findings in 6 consecutive patients

BACKGROUND AND PURPOSE: Intracranial solitary fibrous tumors (ISFTs) are rare mesenchymal neoplasms originating in the meninges. The aim of this study was to describe the CT, MR imaging, and angiographic features of the solitary fibrous tumor and to identify imaging characteristics. MATERIALS AND METHODS: We retrospectively reviewed CT, MR, and angiographic findings in 6 cases of ISFT. We evaluated the size, shape, and location of the tumor; the internal content and margin of the lesion; the pattern of enhancement; and the change of the adjacent structures. Density on noncontrast CT scans, signal intensity on MR images, and angiographic features were also documented. RESULTS: Each lesion appeared as a discrete extra-axial mass (size, 3-7 cm; mean, 5 cm). Five lesions were entirely solid, and 1 had peritumoral cyst. All 5 of the noncontrast CT scans showed hyperattenuated masses, and the tumors exhibited marked heterogeneous enhancement. No lesion contained calcification, and 2 cases showed bone invasions. On the MR images, 4 lesions showed mixed signal intensity on T2-weighted imaging. All of the lesions revealed marked heterogeneous enhancement. All of the tumors had thickening of the meninges adjacent to the tumor. Angiography showed delayed tumor blushing in all, and 3 of them had dysplastic dilation of the tumor vessels. CONCLUSION: Although there are no pathognomonic imaging findings, some imaging features, such as the "black-and-white mixed" pattern on T2-weighted images and marked heterogeneous enhancement, might be helpful in the diagnosis of intracranial solitary fibrous tumor.     

Cross-sectional imaging patterns of desmoplastic fibroma

The aim of this study was to work out the cross-sectional imaging characteristics of desmoplastic fibroma (DF). In 3 patients with histologically proven DF, the imaging characteristics obtained with cross-sectional techniques were reviewed retrospectively. Radiographs and CT scans were available in all patients, and plain and contrast-enhanced MR examinations in 2 patients. Compared with conventional radiographs, CT allowed more accurate assessment of the extent of bone destruction including cortical breakthrough and articular invasion. Intramedullary tumor growth and soft tissue extension was best detected with MRI. Apart from heterogeneity on MR images, DF displayed nonspecific low signal intensity on unenhanced T1-weighted images and an intermediate to high signal intensity including areas of low intensity on T2-weighted images. Desmoplastic fibroma showed a distinct, inhomogeneous gadolinium enhancement. Although cross-sectional imaging features of DF are nonspecific, some MR characteristics, such as inhomogeneous contrast enhancement and the presence of low-intensity regions on T2-weighted images, are helpful in determining the differential diagnosis. Cross-sectional imaging of DF is useful for local staging of the tumor because it provides valuable information about the extent of bone destruction as well as medullary and extraosseous spread.