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.     

SAPHO syndrome: MR appearance of vertebral involvement

PURPOSE: To retrospectively evaluate the magnetic resonance (MR) imaging findings of vertebral involvement in patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. MATERIALS AND METHODS: Ethics committee approval and informed patient consent were not required for this retrospective study. MR images obtained in 12 patients (seven female, five male; mean age, 42 years; range, 16-65 years) with SAPHO syndrome involving the spine were reviewed. One vertebral lesion separated by one or more normal vertebrae was analyzed as a distinct lesion. For each lesion, the number of associated vertebrae with abnormal signal intensity (SI) (ie, single vertebra, two adjacent vertebrae, or more than two adjacent vertebrae) was noted. The following MR imaging findings were evaluated: cortical bone erosion, abnormal vertebral body SI compared with normal vertebral body SI, increased anteroposterior diameter of the vertebral body, soft-tissue involvement, vertebral body height loss of more than 30%, and abnormal SI of the adjacent intervertebral disk compared with the SI of the other disks. RESULTS: Of 24 vertebral lesions found, 17 involved a single vertebra, four involved two adjacent vertebrae, and three involved three or four adjacent vertebrae. Vertebral corner cortical erosion was present in all lesions, and 23 (96%) lesions had anterior vertebral corner involvement. The erosion was confined to a vertebral corner in five (21%) lesions and included the adjacent endplate and/or the anterior cortex of the vertebral body in the remaining 19 (79%) lesions. In four (17%) lesions, involvement of two adjacent vertebral corners on either side of an intervertebral disk mimicked to some extent early disk space infection. An adjacent disk space was narrowed in six (25%) lesions and exhibited abnormal SI in two (8%). Prevertebral tissue thickening was observed in eight (33%) lesions. CONCLUSION: Erosion of a vertebral body corner is consistently seen on MR images of SAPHO vertebral lesions and may support the diagnosis of SAPHO syndrome in the appropriate clinical context.     

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.     

Intertrabecular vertebral metastases: metastases only detectable on MR imaging

Metastatic intertrabecular vertebral tumors that infiltrate the marrow space without trabecular bone alteration are not visible on radiographs or bone scans. To understand the clinical importance of intertrabecular metastases, their histological and radiological aspects were reviewed based on an examination using 69 cadavers. Metastatic tumors were found in 940 of 1653 vertebral bodies. Radiography of the specimen demonstrated lesions in 485 of 940 vertebral bodies (51.6%). Bone scintigraphy showed lesions in 109 of 415 vertebral bodies (26.3%) with tumors examined within 3 months before autopsy, whereas magnetic resonance (MR) images detected 132 of 146 (90.4%) lesions. The intertrabecular metastases were found in 36.9% of the metastatic lesions and was difficult to see on radiography (5.8%) and bone scans (3.3%) whereas MR images detected most of them (94.6%). The intertrabecular metastasis is the most common type of skeletal metastases and is only detectable on MR images.     

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.     

Scintigraphically negative skip metastasis in osteosarcoma

The accurate pre-operative evaluation of the intramedullary extent of osteosarcoma is essential, as it determines the level of bone resection. Radiographs, isotope bone and MR imaging scans have been considered as reliable in detecting skeletal metastasis and skip lesions. We report a case of osteosarcoma of the distal femur with a large skip lesion proximally which was not visualized by either routine radiography or bone scintigraphy, and was not included within the scan field on the initial MR imaging scan. The implications on patient management and possible reasons for failure of imaging to reveal the skip metastasis are discussed. Received 7 October 1996; Revision received 9 January 1997; Accepted 7 February 1997     

Whole-body bone marrow MRI in patients with metastatic disease to the skeletal system

PURPOSE: The purpose of this study was to evaluate the diagnostic potential of a whole-body bone marrow MR protocol in the detection of bone metastases. METHOD: Whole-body bone marrow MRI was performed in 18 patients with known malignant tumors and suspected bone metastases. The imaging protocol consisted of fast T1-weighted and STIR sequences applied in different anatomical positions covering the whole skeleton. MRI findings indicating bone metastases were compared with findings from bone scintigraphy. Metastatic lesions were confirmed by follow-up MR examinations, bone scintigraphy, radiography, or CT. RESULTS: A total number of 216 lesions were detected with MRI in comparison with 159 lesions detected with bone scintigraphy. Follow-up examinations confirmed 105 lesions. MRI detected 96 (91.4%) of the confirmed lesions, whereas bone scintigraphy detected 89 (84.8%). The entire examination, including patient positioning and changing of imaging coils, required 45 min of room time. CONCLUSION: Whole-body bone marrow MRI as used in this study is an effective method for evaluating the entire skeletal system in patients with suspected metastatic disease.     

False negative bone scans in neuroblastoma metastatic to the ends of long bones.

Studies of 12 children with neuroblastoma were performed to assess the comparative sensitivity of skeletal radiography and 99mTc pyrophosphate bone scintigraphy in the detection of metastases to the ends of long bones. A total of 18 lesions were detected in six patients. Fourteen were demonstrated only by radiography, whereas four were positive by both methods. In no case was a lesion detected by scintigraphy alone. Small lesion size, lytic radiographic appearance, metaphyseal location, and technical difficulties in imaging the knee all contribute to the high incidenmce of false negative scans. Lesions in two of the nine patients with metastatic disease to bone would have been missed on the basis of bone scans alone. Accordingly, the radiographic skeletal survey seems to remain a necessary part of the neuroblastoma workup.     

Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma

PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC.     

Staging of spinal metastasis using special techniques of magnetic resonance imaging

The diagnosis of spine metastasis is a problem of great interest which leaves many questions unanswered. In this field MR imaging plays a fundamental role, as the only technique able to directly demonstrate the changes in bone marrow tissue, bound to tumoral activity. The introduction of gradient-echo (GE) sequences has helped reduce examination time. Moreover, with the accurate choice of pulse-sequence parameters (TR, TE, flip angle) additional information is acquired which is not yielded by conventional spin-echo (SE) sequences. Our study was aimed at evaluating MR sensitivity in the different stages of bone metastatic evolution. The comparative adequacy was evaluated of combined bone scintigraphy and conventional radiology versus MR imaging in 62 patients with vertebral metastases. Time interval between bone scan and/or radiological study and MR exam ranged from 10 days to 8 months. SE and GE T1-weighted images, and SE and GE T2-weighted images on the sagittal plane were employed, and axial images; coronal images were rarely acquired. Metastases were demonstrated by MR imaging at 122 vertebral levels, versus 88 true positives of combined scintigraphy and conventional radiology. Scintigraphic false-positives were observed at 15 vertebral levels, versus 9 with radiography. GE sequences were superior to SE ones in detecting vertebral morphologic lesions and bone marrow involvement thanks to their improved resolution and sensitivity. Moreover, GE sequences demonstrated tumoral bone marrow spread and persistent tumoral activity in the follow-up of spine metastases. Our results point to GE sequences as those of choice because of their higher resolution and sensitivity, which also allow response to treatment to be evaluated.     

^99mTc（V）—DMSA骨显像诊断骨转移瘤的临床价值

目的：评价99mTc（V）－DMSA显像在骨转移瘤诊断中的意义。材料和方法：对91例疑骨转移瘤患者行99mTc（V）DMSA全身显像，并与99mTc-MDP全身骨显像及其它检查对比。结果：74例证实存在骨转移瘤者，99mTc．MDP骨显像均显示异常放射性浓聚，99mTc（V）-DMSA显像72例显示了与99mTc-MDP显像某些相同部位的放射性浓聚，2例99mTc（V）DMSA显像阴性。17例骨良性病变，99mTc－MDP骨显像显示轻度异常放射性浓聚，而99mTc（V）-DMSA显像却未见异常的放射性浓聚。结论：99mTc（V）－DMSA诊断骨转移瘤的特异性比99mTc-MDP骨显像高，在骨良恶性肿瘤鉴别诊断中具有重要的临床价值。     

Magnetic resonance-guided transcortical biopsy of bone marrow lesions using a magnetic resonance imaging-compatible piezoelectric power drill: preliminary experience

RATIONALE AND OBJECTIVES: To test utility and specific properties of a commercially available MRI compatible power drill for MR guided transcortical bone biopsy. METHODS: In 17 patients MR-guided bone biopsy was performed in an open low-field scanner (0.2 T), using a piezoelectrically powered drilling machine. Target lesions were osteoblastic in four and nonsclerosed intramedullary in 13 cases. Titanium drills sized 3 to 4 mm and an outer cannula were coaxially used for power assisted cortical trephination. For intramedullary lesion sampling, spring loaded biopsy guns and sharpened cannulas were additionally applied in seven and fluid aspiration in two patients, respectively. RESULTS: The piezoelectric device proved to be fully MR compatible. Trephination and subsequent biopsy was successful in all patients without major complications. The drilling procedure could entirely be performed inside the magnet in case of a lateral approach (n = 11). The net drilling time averaged 7.8 minutes for trephination of nonimpaired diaphyseal bone, but was up to 50 minutes in case of thickened femoral bone. Procedures were complicated by frequent drill loosening, drill obstruction by cortical bone (n = 4) and impaired periosteal grip (n = 5) with damage to the outer cannula (n = 3). CONCLUSIONS: The piezoelectric power drill can be applied safely in a low-field MRI environment and is a valuable tool to facilitate transcortical bone biopsy.     

Role of whole-body diffusion-weighted MRI in detecting bone metastasis

Purpose

The aim of this study was to compare the results of whole-body diffusion-weighted magnetic resonance (DW-MR) imaging with staging based on computed tomography (CT) and nuclear scintigraphy using Tc99m results as the standard of reference.

Methods and materials

Seventeen patients with known malignant tumours were included in the study. The thorax and the abdomen were imaged using breath-hold diffusion-weighted imaging and T1-weighted imaging sequences in the coronal plane. Location and size of osseous metastases were documented by two experienced radiologists. Whole-body DW-MR imaging findings were compared with results obtained at skeletal scintigraphy and CT bone survey.

Results

The mean examination time for whole-body DW-MR imaging was 25.5 min. All bone metastases regardless of the size were identified with whole-body DW-MR imaging; MR imaging depicted more bone metastases than CT. Skeletal scintigraphy depicted osseous metastases in 13 patients (with greater sensitivity to the lower limb), whereas whole-body DW-MR imaging revealed osseous metastases in 13 patients (with greater sensitivity to the spine). DW-MR did not show good results for detection of rib cage metastases. The additional osseous metastases seen with MR imaging were confirmed at follow-up examinations and some had a change in therapy. MR identified 22 % more metastatic lesions when compared to bone scintigraphy and 119 % when compared to CT. Bone scintigraphy identified 80 % more metastatic lesions when compared to CT. On a per-patient basis, whole-body DW-MR imaging revealed sensitivity and specificity values of 100 %.

Conclusion

Whole-body DW-MR imaging was more sensitive in the detection of osseous metastases than were skeletal scintigraphy and CT bone survey.     

The benefit of SPECT when added to planar scintigraphy in patients with bone metastases in the spine.

PURPOSE: This study compared the efficiency of SPECT with planar bone scans in differentiating malignant from benign lesions and in detecting metastases to the spine. METHODS: Planar scintigraphy and SPECT were performed in 37 patients with low back pain without known malignancy and in 38 patients with confirmed malignancy. The type, location, and intensity of tracer accumulation were compared on the planar and SPECT scans. The malignant or benign nature of lesions was proved by radiologic methods, histologic findings, 6 month follow-up, or all of these. RESULTS: More metastases were detected by SPECT (SPECT, 58 of 64; planar, 42 of 64; P < 0.01). In three of seven patients with known malignancy who had a normal result of planar scan, only SPECT detected metastases. Fifty-nine metastases were radiologically mainly osteolytic, one was osteoblastic and four were mixed. Most lesions showed increased radioactivity (40 of 42 on planar scans vs. 45 of 58 on SPECT) and 2 of 42 (5%) vs. 12 of 58 (21%) were cold with marginally increased uptake. One of 58 metastases was a cold lesion seen on SPECT only. Lesions were more often malignant than benign when seen on SPECT in a pedicle (n = 5; malignant = 3, benign = 2), in the body and pedicle (n = 22; malignant = 14, benign = 8), within the vertebral body (n = 5; malignant = 4, benign = 1) and in the whole vertebra (n = 6; malignant = 4, benign = 2). The lesion to background ratio was higher on SPECT than on planar scans (SPECT, 2.26; planar scans, 1.86; P < 0.05 in malignant lesions). CONCLUSIONS: SPECT of the spine improved the diagnostic accuracy of bone scans when added to a planar scan in patients with known malignancy and clinical suspicion of spinal metastases when the planar scan was borderline abnormal. It helps in differentiating between benign and malignant lesions of the spine.     

Comparison of bone single-photon emission tomography and planar imaging in the detection of vertebral metastases in patients with back pain

Bone scan has long been considered to be an important diagnostic test in searching for bone metastases. However, considerable difficulty is encountered in the vertebral region due to the complexity of structures and the fact that other benign lesions, especially degenerative changes, are very common there. Single-photon emission tomography (SPET) has been reported to be useful in the differentiation of benign from malignant conditions. Here we report our experience with bone SPET in the diagnosis of vertebral metastases. This is a retrospective study of technetium-99m methylene diphosphonate (MDP) bone scans in 174 consecutive patients who were referred for the investigation of back pain in our department. MDP planar and SPET images were obtained. Of teh 174 patients, 98 had a known history of malignant tumours. The diagnosis of vertebral metastasis was made on the basis of the patients’ clinical histories and the findings with other imaging techniques such as magnetic resonance imaging, computed tomography or follow-up bone scan. We found that the presence of pedicle involvement as seen on SPET was an accurate diagnostic criterion of vertebral metastasis. SPET had a sensitivity of 87%, a specificity of 91%, a positive predictive value of 82%, a negative predictive value of 94% and an accuracy of 90%. On the other hand, planar study had a sensitivity of 74%, a specificity of 81%, a positive predictive value of 64%, a negative predictive value of 88% and an accuracy of 79% in diagnosing vertebral metastasis. Except with regard to the negative predictive value, SPET performed statistically better than planar imaging. Only 9/147 (6.4%) lesions involving the vertebral body alone and 3/49 (6.1%) lesions involving facet joints alone were subsequently found to be metastases. We conclude that bone SPET is an accurate diagnostic test for the detection of vertebral metastases and is superior to planar imaging in this respect. Received 20 December 1997 and in revised form 16 March 1998     

Osteochondritis dissecans: analysis of mechanical stability with radiography, scintigraphy, and MR imaging

Twenty-one joints with stable (n = 9) or loose (n = 12) osteochondritis dissecans (OCD) lesions were examined in 15 subjects with plain radiography, three-phase bone scintigraphy, and magnetic resonance (MR) imaging. The lesion size and the thickness of the sclerotic margin as measured on plain radiographs were good parameters for predicting loosening. However, bone scintigraphy was more sensitive and specific in determining the mechanical stability of OCD lesions. MR imaging permitted direct visualization of loosening and fragment displacement; the latter permits differentiation of in situ loosening from a grossly unstable lesion. The noninvasive nature of bone scintigraphy and MR imaging makes them potentially preferable diagnostic modalities to arthrography for evaluating the mechanical status of OCD lesions.     

Diagnostic evaluation of cancer patients with pelvic pain: comparison of scintigraphy, CT, and MR imaging

Pelvic pain in cancer patients can result from several causes. The most appropriate choice of imaging techniques for evaluating such patients has not been established. We evaluated 27 cancer patients with pelvic pain by using radionuclide bone scintigraphy (24 patients), abdominal CT (27 patients), and pelvic MR imaging (27 patients) and used the correlation between symptoms and imaging findings to compare these imaging methods. The study population included 11 patients with Ewing sarcoma, six with other sarcomas, five with colorectal cancers, and five with other tumors. All patients had pelvic pain, and eight had pain radiating to a leg. Twenty-three patients had soft-tissue masses, and 19 had bone metastases; 16 had both. Findings on bone scans explained the symptoms in 17 (71%) of 24 patients, findings on CT in 23 (85%) of 27 patients, and findings on MR imaging in 25 (93%) of 27 patients. The difference between bone scanning and CT or MR was statistically significant (p less than .05); however, the difference between CT and MR imaging was not significant (p greater than .05). MR imaging detected 41 (98%) of 42 relevant lesions, whereas CT detected 31 (74%) of 42, and bone scanning 17 (44%) of 39. We conclude that MR is superior to either bone scanning or CT in the initial evaluation of pelvic pain in cancer patients. Such information can be important in directing the treatment of these patients.     

Bone scintigraphy and somatostatin receptor scintigraphy in pediatric patients with bone involvement in Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a granulomatous disease which can involve multiples sites of the body. Diagnostic imaging is of utmost importance in the management of these patients. Up to now radiographic skeletal survey and bone scintigraphy (BS) have been used to assess bone involvement (both with low specificity). Magnetic resonance imaging (MRI) and CT have been used to assess visceral involvement but with the limitation that they cannot give information about the functional status. Recently somatostatin receptor scintigraphy (SSRS) has been proposed to detect active lesions and to monitor response to treatment. The aim of this study is to assess bone and somatostatin receptor scintigraphy in the detection of bone involvement in LCH in children. Twenty scintigraphies (12 SSRS and 8 BS) were performed in seven patients (3 girls and 4 boys) aged at diagnosis: 18 month-12 years (mean age 6 years). The findings obtained in the scintigraphies were compared with clinical evolution and other imaging techniques. Bone scintigraphy detected all the LCH bone lesions, and discovered one unknown lesion. SSRS scintigraphy visualised the active lesions in 3 patients (clinical and other imaging techniques were also positive). SSRS was negative in one patient classified as disease free and another in clinical remission. SSRS detected 2 new unknown bone lesions, but could not detect LCH bone lesions confirmed in other imaging techniques in 2 patients. Somatostatin receptor and Bone scintigraphy can be used to detect active LCH bone lesions in children and can help to monitor response to treatment. Further studies with more patients are needed to confirm the diagnostic usefulness of these techniques.     

良恶性多椎体压缩性骨折的MRI诊断

目的:探讨良、恶性多椎体压缩性骨折的MR影像学特征。方法:回顾220例(良性104例,恶性116例)460个压缩椎体,比较病变椎体排列特性及MRI征象。结果:恶性多椎体压缩骨折,椎体跳跃式侵犯多见,66%的病灶集中在椎体后2/3髓质,T1WI呈穿凿样、片状低信号,并椎弓根、椎板表现膨胀性骨质破坏,椎间盘形态正常;良性多椎体压缩性骨折,椎体连续性病变多见,终板表现带状异常信号,常伴椎间盘撕裂、椎间隙狭窄或增宽,椎体碎裂,但无软组织肿块。结论:MR的特征性改变能准确鉴别良、恶性压缩骨折。