Factors influencing visualization of vertebral metastases on MR imaging versus bone scintigraphy

OBJECTIVE: The purpose of this study was to investigate whether the location and size of vertebral body metastases influence the difference in detection rates between MR imaging and bone scintigraphy. MATERIALS AND METHODS: We retrospectively evaluated the vertebral body lesions detected on MR imaging in 74 patients with known widely disseminated metastatic disease. Three radiologists independently reviewed the MR images and bone scintigraphs. MR imaging findings included lesion size and its spatial relationship to the bony cortex (intramedullary, subcortical, and transcortical) and results were correlated with those of planar technetium 99m bone scintigraphy. RESULTS: Findings on bone scans were negative for all intramedullary lesions without cortical involvement shown on MR imaging, regardless of their size. Findings on bone scans (71.3% for transcortical and 33.8% for subcortical) were frequently positive for lesions with cortical involvement (trans- or subcortical), and the probability of positive findings on bone scans was also influenced by the lesion size. Statistical analysis showed a positive correlation among cortical involvement, lesion size, and positive findings on bone scintigraphy (p < 0.0001). CONCLUSION: Location (the presence of cortical bone involvement on MR imaging) and size of the vertebral body metastases appear to be important contributing factors to the difference in detection rates between MR imaging and bone scintigraphy. Cortical involvement is likely the cause of positive findings on bone scans. Early vertebral metastases tend to be small and located in the medullary cavity without cortical involvement, and therefore, findings may be positive on MR images but negative on bone scans.     

MR imaging of bone metastasis]

One hundred and three patients with known malignancy and suspected bone metastasis underwent magnetic resonance imaging. In 93%, the metastatic lesions, detected both on plain films and radionuclide bone scans, showed decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted images. All lesions, except one lesion showing much blastic change on plain films, showed contrast enhancement with Gd-DTPA administration. Although further investigation is needed, a correlation between the type of primary malignancy and the signal intensity of the metastatic lesion is suggested. Among 312 metastatic lesions detected by MR imaging, 272 lesions (87%) and 134 lesions (40%) were also detected by radionuclide bone scans and plain films, respectively. In five cases, MR imaging clearly revealed the lesion compressing the spinal cord, which helped us formulate a therapeutic plan. We conclude that MR imaging is the most sensitive examination for detecting bone metastasis and is necessary for planning treatment.     

Whole-body MR imaging for detection of bone metastases in children and young adults: comparison with skeletal scintigraphy and FDG PET.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of whole-body MR imaging, skeletal scintigraphy, and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for the detection of bone metastases in children. SUBJECTS AND METHODS: Thirty-nine children and young adults who were 2--19 years old and who had Ewing's sarcoma, osteosarcoma, lymphoma, rhabdomyosarcoma, melanoma, and Langerhans' cell histiocytosis underwent whole-body spin-echo MR imaging, skeletal scintigraphy, and FDG PET for the initial staging of bone marrow metastases. The number and location of bone and bone marrow lesions diagnosed with each imaging modality were correlated with biopsy and clinical follow-up as the standard of reference. RESULTS: Twenty-one patients exhibited 51 bone metastases. Sensitivities for the detection of bone metastases were 90% for FDG PET, 82% for whole-body MR imaging, and 71% for skeletal scintigraphy; these data were significantly different (p < 0.05). False-negative lesions were different for the three imaging modalities, mainly depending on lesion location. Most false-positive lesions were diagnosed using FDG PET. CONCLUSION: Whole-body MR imaging has a higher sensitivity than skeletal scintigraphy for the detection of bone marrow metastases but a lower sensitivity than FDG PET.     

Intramedullary osteosclerosis: imaging features in nine patients.

PURPOSE: To determine the conventional radiographic, computed tomographic (CT), magnetic resonance (MR) imaging, scintigraphic, and histologic features of intramedullary osteosclerosis and to review the clinical features. MATERIALS AND METHODS: Nine female patients with leg pain and imaging features indicative of intramedullary sclerosis were seen during a 25-year period. None of the patients had a history of trauma or infection, familial bone disease, or related abnormal laboratory findings. Imaging studies included radiography (n = 9), CT (n = 4), MR imaging (n = 5), and skeletal scintigraphy (n = 5). Histologic correlation was available in five patients. RESULTS: Sixteen bone lesions (midtibia, n = 14; distal fibula, n = 1; and proximal femur, n = 1) were evident. Both lower extremities were involved in seven patients, and a single extremity was involved in two. Intramedullary sclerosis was present, as was cortical thickening, mainly in the diaphysis of the long bones, without extensive periosteal reaction or soft-tissue involvement. Findings at bone scintigraphy were positive in all lesions. Histologic analysis showed nonspecific changes of markedly sclerotic bone with a variable degree of mineralization and maturity. CONCLUSION: Intramedullary osteosclerosis is a distinct disorder that typically affects the diaphysis of one or both tibiae in women. Characteristic imaging findings, when coupled with clinical information, allow precise diagnosis.     

骨母细胞瘤的影像学诊断

目的 :评价影像学检查对骨母细胞瘤的诊断价值。方法 :对 18例经手术病理证实骨母细胞瘤的影像学表现进行回顾性分析。 18例均摄了平片 ,6 / 18例均行CT平扫和增强、10 / 18例均行MR平扫和增强。结果 :脊柱 6例 ,颅骨 4例 ,胫骨 2例 ,股骨 2例 ,肱骨、骨盆、距骨、软组织各 1例。骨母细胞瘤以脊柱及长管状骨好发。平片和CT多表现、膨胀性囊状骨破坏 ,病灶内常有钙化、骨化 ,边缘常有轻度硬化缘 ;MRI检查多呈不均匀性长T1、T2 囊状膨胀性骨质破坏 ,增强扫描多呈不均匀性强化 ,部分见液平和软组织肿块 ;一般无骨反应。结论 :CT、MRI对骨母细胞瘤诊断较平片有优势 ,综合影像学检查能提高诊断符合率。     

探讨双b值对比法在肝脏局灶性病变诊断中的作用

目的：探讨双b值对比法在肝脏局灶性病变诊断中的价值.方法：回顾性分析108例行肝脏MRI平扫及动态增强扫描患者的病例（肝癌44例.转移瘤4例,血管瘤40例,囊肿18例,局灶性结节增生2例）,分为良恶性两组（恶性组48例,A组;良性组60例,B组）.均行b值为500和800 s/mm2的DWI扫描,测量肝脏病变的信号强度值,计算相对信号比R500、R800（R=病灶信号/背景信号）,观察不同b值时病变的信号变化情况△R（△R=R800-R500）.采用X2检验分析采用△R值诊断良恶性病变与病理结果的一致性.结果：△R≥0.25有42例（PA组）,△R〈0.25（PB组）有66例,其中PA中有4个为良性病变（均为血管瘤）,PB中有10个为恶性病变（2个转移瘤,8个肝癌）,差异无统计学意义（X2=1.786,P〉0.05）.结论：双b值对比法在肝脏局灶性病变的定性诊断中具有可行性.     

Magnetic resonance imaging versus radionuclide scintigraphy in screening for bone metastases.

AIM: To determine the frequency of isolated, asymptomatic metastases of the peripheral skeleton in patients with breast and prostate cancer. METHODS: A retrospective review was performed of staging skeletal scintigrams. Patients with hot spots in the peripheral skeleton in the absence of convincing evidence of metastatic disease in the axial skeleton were followed-up to determine the nature of the peripheral lesion(s) based on other imaging modalities, serial imaging or biopsy, and to determine if the lesion(s) had been symptomatic at the time of the scintigram. SUBJECTS: 200 patients with histologically proven carcinomas of the breast or prostate. RESULTS: Four patients (2%) had isolated metastatic involvement of the peripheral skeleton, and would, therefore, have been wrongly staged by a magnetic resonance 'marrow screen' of the axial skeleton. However, in three of these patients the lesions were painful, prompting diagnostic plain radiographs independent of the scintigraphic findings. Twelve patients (6%) had isolated scintigraphic abnormalities of the peripheral skeleton suggestive of metastatic disease but which on further investigation were shown to be benign lesions. CONCLUSION: A limited magnetic resonance (MR) 'marrow screen' confined to the axial skeleton would not result in any significant loss of accuracy in staging patients with breast and prostate carcinoma compared with skeletal scintigraphy. Given the proven increased sensitivity of MR over skeletal scintigraphy in the detection of bone metastases, and the additional information MR provides, it is likely to provide a more accurate basis for management.     

MR imaging of thoracic and abdominal wall infections: comparison with other imaging procedures

Infections of the chest and abdominal wall are rare but potentially fatal disorders that can occur spontaneously or in association with diabetes mellitus, immunosuppression, or trauma. The condition (either in the form of necrotizing fasciitis and/or pyomyositis) is difficult to diagnose clinically because of poor localizing signs. Prognosis depends on early recognition, extent of disease, and type of causative organism. Pathologically, the infections can manifest as cellulitis, abscess, and/or granulation tissue formation. To determine the value of MR imaging in the assessment of these infections, we compared the findings of MR with those of CT, sonography, scintigraphy, and plain radiography in 13 patients with proved thoracic and/or abdominal wall infection. The imaging findings were correlated with microbiological, pathologic, and/or surgical data. The isolated pathogens were Staphylococcus aureus (n = 6), Klebsiella pneumoniae (n = 1), Mycobacterium tuberculosis (n = 4), and Streptomyces somaliensis (n = 2). In 10 of 13 patients, MR imaging and CT were comparable and proved accurate in detecting the nature and extent of the inflammatory process. In seven of the patients, CT also was useful in guiding percutaneous biopsy and/or partial drainage procedures. Coronal and sagittal MR images were helpful for planning surgery. Rib osteomyelitis was missed with both techniques in one patient; in two other patients who did not have CT, MR imaging missed osteomyelitis of the ribs, the spinous process of a vertebral body, and the iliac bone. Sonography underestimated the extent of the disease in all 13 patients, but detected fluid collections in six. Findings on scintigraphy and plain radiography were the least contributory to the diagnosis and treatment of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Telangiectatic osteosarcoma: radiologic-pathologic comparison

PURPOSE: To describe the imaging characteristics of a large series of telangiectatic osteosarcomas with pathologic findings for comparison. MATERIALS AND METHODS: The authors retrospectively reviewed 40 pathologically confirmed telangiectatic osteosarcomas. Patient demographics and images from radiography (n = 36), bone scintigraphy (n = 17), angiography (n = 4), computed tomography (CT) (n = 25), and magnetic resonance (MR) imaging (n = 27) were evaluated by three authors in consensus for lesion location, size, and intrinsic characteristics. There were 27 men (68%) and 13 women (32%) in the study, with an age range of 4-83 years (mean age, 24 years). RESULTS: Lesions frequently affected the femur, tibia, and humerus. Radiographs showed geographic bone lysis, a wide zone of transition, and matrix mineralization. CT demonstrated low attenuation, MR demonstrated high signal intensity on T2-weighted images, and both demonstrated hemorrhage, which simulated the appearance of aneurysmal bone cyst. Viable sarcomatous tissue surrounding hemorrhagic and/or necrotic regions was best seen at contrast material-enhanced CT and MR imaging, with thick peripheral, septal, and nodular enhancement in all cases. Subtle matrix mineralization in this viable tissue was best seen at CT. An associated soft-tissue mass was also seen in 19 of 25 cases (76%) at CT and in 24 of 27 cases (89%) at MR imaging. CONCLUSION: CT and MR imaging findings of telangiectatic osteosarcoma often include thick nodular tissue (and matrix mineralization at CT) in a largely hemorrhagic and/or necrotic osseous lesion with an associated soft-tissue mass, which allows distinction from aneurysmal bone cyst.     

MR imaging of skeletal metastases from medulloblastoma

The findings of MR imaging in 3 patients with bone metastases from medulloblastoma are reported. The first patient showed focal lesions of low signal intensity on T1-weighted spin echo images at a time when bone scintigraphy was negative for metastases. This patient later developed extensive osteosclerotic lesions visible on plain films. The bone marrow of the second patient showed diffuse low signal intensity on T1-weighted images. After chemotherapy the signal intensity of the bone marrow increased which correlated with a return of normal hematopoietic tissue. A response to chemotherapy was also found on MR imaging and repeat bone marrow biopsies in a third patient. A consistent finding was a low signal intensity on pre-gadolinium images, but the pattern (focal or diffuse abnormal signal intensity) was different in each patient. To our knowledge, this is the first report on MR imaging findings in bone metastases from medulloblastoma.     

Carpal avascular necrosis: MR imaging

The authors evaluated the use of magnetic resonance (MR) imaging in diagnosis of avascular necrosis (AVN) of carpal bones by examining 21 patients with wrist pain and two healthy volunteers. MR images were compared with conventional radiographs in every case and with bone scintigrams in 18 cases. MR imaging was slightly less sensitive than bone scintigraphy in depicting AVN, but in patients who were imaged with long repetition time (TR)/long echo time (TE) sequences in addition to short TR/short TE sequences, MR imaging was found to be more specific. While the authors believe that bone scintigraphy remains the screening test of choice for patients with wrist pain and normal plain radiographs, MR imaging promises to add significant diagnostic information in cases in which bone scans are abnormal.     

Primary musculoskeletal tumors: examination with MR imaging compared with conventional modalities

In 176 cases of primary musculo-skeletal tumors, the informative value of magnetic resonance (MR) imaging was compared with that of plain radiographic examination, angiography, scintigraphy, and computed tomography (CT). In all patients the surgical and histopathologic results were known. For bone tumors confined to the bone, MR imaging was excellent for evaluation of intraosseous extent, but it could not be proved significantly better than CT or scintigraphy. MR imaging was inferior to plain radiography and CT for evaluation of calcification, ossification, cortical destruction, and endosteal/periosteal reaction. For soft-tissue tumors and bone tumors with soft-tissue extension, MR imaging was significantly better than the other modalities in all variables examined: delineation between tumor and muscle, tumor and vessel, tumor and fat, tumor and joint, and tumor and bone, as well as depicting intralesional necrosis and bleeding.     

High-resolution sonography of the rib: can fracture and metastasis be differentiated?

OBJECTIVE: Our aim was to evaluate whether high-resolution sonography can provide additional information concerning rib lesions compared with radiography or bone scintigraphy. MATERIALS AND METHODS: Fifty-eight patients with high-uptake rib lesions seen on bone scintigraphy were selected. Radiography and rib high-resolution sonography were performed on these patients. High-resolution sonography was performed using a linear 5-12 MHz transducer. By means of clinical history, histopathologic examination, and follow-up observation, these patients were classified into rib fracture (n = 37), rib metastasis (n = 18), or unknown (n = 3) groups. High-resolution sonography images of the 55 proven cases were reviewed for the presence of five representative findings: cortical disruption, callus formation, cortical deformity, mass, or bone destruction. The frequencies of these findings were compared between the groups with fracture and metastasis. RESULTS: Rib lesions were matched by bone scintigraphy and high-resolution sonography in 53 (96%) of 55 patients and by bone scintigraphy and plain radiography in 23 (42%) of 55 patients. High-resolution sonography revealed 17 (94%) of 18 patients with metastasis and 36 (97%) of 37 patients with rib fractures. Metastatic lesions were seen as mass formation (n = 13) and irregular bone destruction (n = 7) on high-resolution sonography. Fracture was seen as cortical disruption with or without hematoma (n = 17), callus formation (n = 9), or cortical deformity, such as angling or stepping (n = 12). CONCLUSION: High-resolution sonography of the ribs is a useful method of characterizing rib lesions in patients who have hot-uptake lesions on bone scintigraphy.     

MR and other imaging methods in the investigation of mycetomas

Purpose: To report features of mycetomas (actino- and eumycetoma infection), which belong to the so-called rare bone infections, as evaluated by MR and other imaging methods and to assess chemotherapy treatment.Material and Methods: Twenty patients (average age 57 years) were diagnosed by different modalities. Analyses of 57 plain films, 31 three-phase bone scans, 28 CT and 35 MR examinations were performed. The MR protocol included T1-weighting without and with contrast, T2-weighted, proton density and fat suppressing sequences.Results: Signs of chronic osteomyelitis were seen in plain films of 10 patients (50%), but the healing process was difficult to assess. Bone scintigraphy was positive in 12 patients (60%). In 14 patients (70%), CT could demonstrate bone lesions, but the healing process was difficult to estimate in 4 patients. MR imaging provided accurate diagnostic information in 15 cases (75%). In 16 patients (80%), small lesions could be identified due to grains, which seemed to differentiate mycetoma from other infections and tumorous lesions. MR examination gave definitive answer about the healing process in 18 cases (90%).Conclusion: MR investigation was superior to the other imaging techniques in the evaluation of mycetoma and the assessment of therapy.     

Solid variant of aneurysmal bone cysts in long tubular bones: giant cell reparative granuloma

OBJECTIVE: The purpose of this study was to determine the age distribution, location, and imaging features of histologically proven solid variants of aneurysmal bone cysts in long tubular bones. MATERIALS AND METHODS: We performed a retrospective review of imaging studies of histologically proven solid aneurysmal bone cysts in long bones between 1961 and 2001. There were 30 cases comprising 29 radiographic, six CT, and eight MR imaging examinations. The lesions were evaluated for bone involved, location within a long bone, matrix, size, soft-tissue mass, and MR imaging characteristics. The imaging findings were correlated with the histologic findings. RESULTS: The patients were 17 females and 13 males ranging in age from 2 to 58 years (mean, 18 years). The bones involved were the femur (n = 10), the ulna (n = 7), the tibia (n = 7), the humerus (n = 2), the radius (n = 2), and the fibula (n = 2). The lesions were five juxtaarticular, 13 metaphyseal, one diametaphyseal, and 11 diaphyseal. The location was eccentric in 20 cases, of which two were intracortical and two periosteal, and central in 10. Lesion size varied between 1 and 7 cm. Thirty-three percent of lesions were nonaneurysmal. Four lesions were mineralized. A soft-tissue mass was present in four cases. Four lesions showed a permeative-lytic pattern simulating a malignant process. Unusual findings included periosteal reaction and development of a solid aneurysmal bone cyst in a preexisting fracture. MR imaging showed solid elements in all cases and pronounced edema in 50% of cases. CONCLUSION: Solid aneurysmal bone cyst is a reactive nonneoplastic bone lesion with varied imaging characteristics; one third of lesions are nonaneurysmal.     

Imaging of soft-tissue myxoma with emphasis on CT and MR and comparison of radiologic and pathologic findings

PURPOSE: To determine the imaging characteristics of soft-tissue myxoma, with emphasis on computed tomographic (CT) and magnetic resonance (MR) imaging findings and pathologic comparison. MATERIALS AND METHODS: Records of 45 pathologically confirmed soft-tissue myxomas in 44 patients were retrospectively reviewed. Patient demographics and radiographs (n = 20), bone scintigrams (n = 2), angiograms (n = 3), and ultrasonographic (US) (n = 6), CT (n = 14), and MR images (n = 33) were evaluated by two musculoskeletal radiologists with agreement by consensus for lesion location, lesion size, and intrinsic characteristics. RESULTS: Soft-tissue myxoma more commonly affected women (59%; average age 52 years) and manifested as a slowly enlarging (64%) painful (51%) mass. Lesions were most frequently intramuscular (82%) and involved the thigh (51%). An appearance similar to that of a cyst was seen at CT (at which the lesions demonstrated low attenuation) and at MR imaging (at which the lesions demonstrated markedly high signal intensity on T2-weighted images) in all cases because of the high water content of mucin that was seen histologically. The true solid architecture of these lesions was best depicted in all cases at US (at which the lesions were hypoechoic, not anechoic) and on MR images obtained with contrast material (at which the lesions demonstrated internal enhancement). A small amount of tissue similar to fat surrounding these intramuscular myxomas (71% at MR imaging) corresponded histologically (70%) to atrophy of surrounding muscle. CONCLUSION: Soft-tissue myxoma often demonstrates characteristic US, CT, and MR imaging findings, including intramuscular location, intrinsic high water content, and a surrounding rim of fat.     

地塞米松介入延迟骨显像鉴别良恶性骨病变

目的探讨地塞米松介入24h延迟骨显像鉴别良、恶性骨病变的临床价值.方法20例恶性骨病变患者(共242个病灶)、21例良性骨病变患者(共102个病灶)随机分成非介入组和介入组进行对照研究.非介入组于注药后3、24h分别进行骨显像,介入组于3h显像后分次口服醋酸地塞米松片共6.75mg,于24h行骨显像.勾划ROI,计算24h/3h放射性摄取比值(RUR).结果非介入组与介入组良性病变间的RUR值差异无显著性(q=0.94,P>0.05);非介入组与介入组的恶性病变之间、非介入组的良性病变与恶性病变之间、介入组的良性病变与恶性病变之间RUR值的差异均有显著性(q分别为20.10,1.81,16.39,P分别<0.01,<0.05,<0.01).非介入组RUR值判别恶性骨病变的灵敏度、特异性、准确性分别为75.5%、86.2%、65.8%,介入组分别为81.5%、87.5%、83.1%.结论口服地塞米松介入24h延迟骨显像可明显提高骨显像的诊断效能,方法简便易行,具有临床应用价值.     

Hill-Sachs lesion: comparison of detection with MR imaging, radiography, and arthroscopy.

Magnetic resonance (MR) imaging has proved to be a valuable method for documenting Hill-Sachs lesions. The authors retrospectively analyzed the diagnostic interpretations at plain film radiography, arthroscopy, and MR imaging in 76 patients. The analysis revealed that neither radiography nor arthroscopy displayed the lesion with sufficient accuracy to represent a true standard of reference for the evaluation of MR imaging in the diagnosis of the Hill-Sachs lesion. The data from the diagnostic interpretations were analyzed in three ways, each of which revealed that findings at MR imaging were more helpful than findings at radiography and/or arthroscopy in the diagnosis of the Hill-Sachs lesion. When the agreement of findings in two or three methods was used to assign a final diagnosis, MR imaging resulted in sensitivity of 97%, specificity of 91%, and accuracy of 94% in the detection of Hill-Sachs lesions.     

颅骨动脉瘤样骨囊肿的影像学表现

目的：探讨颅骨动脉瘤样骨囊肿的影像学表现，提高对颅骨动脉瘤样骨囊肿的认识。资料与方法：搜集经手术病理证实的4例颅骨动脉瘤样骨囊肿，全部病例均作了CT平扫与MRI检查，其中1例摄有颅骨平片，1例MR／增强扫描，1例DSA检查。结果：4例颅骨动脉瘤样骨囊肿中，1例位于左蝶骨嵴和左眶骨处，2例位于左颞骨。1例位于右额骨。CT上均表现为不同程度的膨胀性吹气球样溶骨破坏区，密度不均匀；MRI示有出血、囊变及液面，T1WI和R2WI上呈混杂信号，1例增强后示肿瘤实质和邻近脑膜强化；血管造影示血管有推移改变。结论：颅骨动脉瘤样骨囊肿的影像学表现有一定的特征性，CT与MRI相结合能提示诊断，并有助于评价周围结构。