Fast spin echo MRI and bone scintigraphy in the detection of skeletal metastases

Standard Spin Echo (SE) magnetic resonance imaging (MRI) is known to be a very sensitive method for the detection of bone metastases and in comparison to skeletal scintigraphy, MRI detects more lesions when field of view includes the area of suspicion. However, only with the introduction of new fast SE sequences, have MRI protocols, for the detection of metastases, become rapid enough to make it a potential screening procedure for metastatic disease. Twenty-one patients with a suspicion of carcinomatous bone metastases were evaluated with both conventional T1 weighted (T1w), T2 weighted (T2w) and fast T2w SE (FSE) sequences (thoraco-lumbar spine and pelvis) and whole body bone scintigraphy. Conventional and fast T2w SE sequences detected the same number of lesions while bone scintigraphy detected only 70% of the lesions seen on MRI. However, more importantly, in 11 of the 21 patients bone scintigraphy detected lesions outside the MR field of view, lying in the ribs, skull, scapulae and extremities and in 4 of them, MRI was negative. Our results suggest first that fast SE MRI can replace conventional SE MRI when looking for carcinomatous bone metastases in the axial skeleton, with the advantage of a four to six times reduced acquisition time for fast T2w sequences. However, the limited field of view still limits the usefulness of MRI and whole body bone scintigraphy remains the screening modality for bone metastases. Fast MRI plays an important complementary role. Correspondence to: G. K. von Schulthess     

How does iliac crest bone marrow biopsy compare with imaging in the detection of bone metastases in small cell lung cancer?

Iliac crest bone marrow biopsy (BMB) has often been used as the gold standard for the detection of bone marrow metastases in small cell lung cancer (SCLC). However, it is likely to lead to numerous false-negative results. For this reason, we compared the results of bone scintigraphy (BS), magnetic resonance imaging (MRI), and BMB in 48 sequential patients affected with pathologically confirmed SCLC (47 were evaluable; mean age, 58.4 years). The three procedures were carried out within 1 week, no treatment being performed during this period. Whole-body scans and spot views were obtained in the anterior and posterior projections. For MRI, only the thoracolumbar spine, the sternum and the pelvis were scanned, using spin-echo T1-weighted sequences, resulting in an acquisition time of less than 45 min. Only five BMBs were rated as positive. In these cases, both BS and MRI were also positive. The other 42 biopsies were negative. Among them, in ten cases both BS and MRI were positive. In 21 cases, both BS and MRI were negative. In five cases MRI was positive while BS was negative. Finally, in six cases MRI was negative whilst BS was positive. In most cases in which either BS or MRI was positive, follow-up scans confirmed the initial findings. This study suggests that BMB is more invasive and less sensitive than BS or MRI in detecting bone metastases. MRI seems to be more sensitive than BS in detecting small spinal or pelvic metastases. Whole-body bone scintigraphy is more sensitive in detecting skull, costal or peripheral metastases. BS and MRI should be used in combination and may replace BMB in the detection of bone metastases in SCLC. Correspondence to: I. Perrin-Resche     

Comparison of whole-body MRI with automatic moving table technique and bone scintigraphy for screening for bone metastases in patients with breast cancer

The aim of this study was presentation of a whole-body MRI technique with a moving table as a screening tool for bone metastases in patients with breast cancer. Twenty-two patients with breast carcinoma underwent both a planar whole-body bone scintigraphy and whole-body MRI at 1.5 T. The MRI images were acquired with a moving table at six different anatomical positions within a measurement time of 20 min. Coronal images were acquired using a short-tau inversion recovery sequence, accomplished by an axial T2-weighted turbo-spin-echo sequence through the head, and a T1-weighted opposed-phase sagittal 2D fast low-angle shot sequence covering the whole spine. The MRI findings indicating bone metastases were compared with findings from bone scintigraphy. Metastatic lesions were confirmed by follow-up examinations over 1 year. Twelve patients showed bone metastases. Whole-body MRI was superior to bone scintigraphy in predicting lesion origin with a sensitivity of 92% (bone scintigraphy 83%), a specificity of 90% (scintigraphy 80%) and an accuracy of 91% (scintigraphy 82%). The MRI showed additional findings such as metastases of the lung and liver. Whole-body MRI with moving table technique may be an effective method of total body screening for bone in selected patients with breast carcinoma and a high risk of distant metastases, although with the higher costs of MRI bone scintigraphy must still be considered as the first method for screening patients with breast cancer.     

The value of bone marrow scintigraphy using 99mTc monoclonal antigranulocyte antibodies in complement to bone scintigraphy in detecting bone metastases from primary breast cancer

This prospective study evaluates bone marrow scintigraphy (BMS) in detecting bone metastases from primary breast cancer when performed in complement to conventional bone scan (BS). Sixty women predominantly with low-stage disease underwent BS followed by BMS within 1-35 days using BW250/183 antigranulocyte antibodies. A receiver operating characteristic (ROC) analysis was performed to compare BS to BS+BMS on a patient-by-patient basis using a 'gold standard' composed of subsequent computed tomography, magnetic resonance imaging, X-ray or BS examinations and at least a 12 month follow-up. Metastases were present in eight out of 60 patients (13%). Specificity was improved by BS+BMS compared to BS alone (90%, 65%) as well as positive predictive value (62%, 27%), accuracy (87%, 72%), positive (10.4, 2.4) and negative (0.20, 0.00) likelihood ratios. Sensitivity (100%, 88%) and negative predictive value (100%, 97%) were similar for BMS+BS and BS alone. As a result of BMS, clinical management was modified in 15 patients (25%). In conclusion, BMS supplements BS by improving specificity, positive predictive value and accuracy in detecting breast cancer bone metastases. The ROC curves show improved specificity for BS+BMS at the same sensitivity compared to BS alone. Consequently, BMS may be useful in low-stage subjects with positive or equivocal BS for metastases.     

核素骨显像与MRI检测脊柱转移瘤的对比研究

目的：比较核素骨显像与MRI对脊柱转移瘤的诊断价值。方法；对76例经病理证实为恶性肿瘤的患者进行骨显像与MRI检查，比较骨显像与MRI对脊柱部位病变的检查情况。结果：骨显像、MRI对脊柱转移瘤的阳性病例及阳性病灶数的检出率拉近，阳性病例检出率为68／81和61／81，阳性病灶检出率为167／536和156／536。二者我椎转移为好发段，MRI对胸椎病灶的检出率优于骨显像，检出率分别为83／237和64／237；二者对腰椎的检出率无差别，骨显像对颈椎、骶椎的检出率优于MRI（颈椎分别为15／63和6／63，骶椎分别为23／78和10／78）。对多发病灶的检出MRI优于骨显像，检出率分别为143／237和116／237。结论：在显示脊柱肿瘤骨转移方面，总体的敏感性二者接近，在具体部位二者各有优势，在多发病灶上MRI优于骨，骨显像因其简单易行，仍为肿瘤患者病情初始评价的选择，在其对临床问题解释不够充分时，则应采用MRI作为补充。     

Comparative diagnostic value and therapeutic relevance of magnetic resonance imaging and bone marrow scintigraphy in patients with metastatic solid tumors of the axial skeleton

PURPOSE: To evaluate the comparative impact of magnetic resonance imaging (MRI) and bone marrow scintigraphy (BMS) in bone marrow metastases of solid tumors. METHODS: In 20 patients with solid tumors MRI of the axial skeleton and whole-body BMS were retrospectively reviewed. Detectability of metastases, extent of disease and therapeutic implications were assessed. RESULTS: In 15/20 (75%) patients MRI and BMS concordantly revealed bone marrow metastases of the axial skeleton. In nine of these 15 patients (60%) MRI showed more metastases. Local radiotherapy or surgery was performed in seven of these cases (78%). BMS detected additional metastases of the appendicular skeleton in 8/15 (53%) patients. In 4/20 cases (20%) the imaging findings were discordant. In three patients with degenerative changes (n=2) or lipoma (n=1) BMS was false positive. In another patient BMS failed to detect metastases proven by MRI and clinical follow-up resulting in subsequent radiation therapy. One patient had normal bone marrow. CONCLUSION: MRI appears to be more sensitive and specific in the detection of bone marrow metastases in the axial skeleton and is of clinical importance for subsequent local therapy.     

Whole-body MRI using a rolling table platform for the detection of bone metastases

The aim of this study was to compare the results of whole-body MRI using a recently developed rolling table platform with findings of nuclear scintigraphy in patients with bone metastases. Twenty-six patients with known or suspected bone metastases who had undergone radionuclide scintigraphy were examined by MRI. Patients were placed on a rolling table platform with integrated phased-array surface coils [BodySURF (system for unlimited field of view)] capable of pulling the patient through the isocenter of the magnet. Using a five-station approach three different image sets (T1-weighted gradient recalled echo, half-Fourier acquired single-shot turbo spin echo, and short tau inversion recovery) were collected in the coronal plane. In addition, the spine was imaged in the sagittal plane. The MRI findings were compared with the results obtained by scintigraphy. The whole-body MR examination lasting merely 40 min was feasible in all 26 patients. The MRI revealed excellent correlation with scintigraphy regarding metastatic lesions. A total of 60 regions with metastatic lesions were identified on bone scintigraphy. Fifty-three regions were detected on identical locations by MRI. The regions missed by MRI were located mainly in ribs and skull. The MRI could identify additional bone metastases in spine, pelvis, and femur. The MRI screening for bone metastases correlated well with bone scintigraphy. Use of the rolling table platform permits rapid imaging based on three different contrast mechanisms of the entire skeletal system.     

Screening for skeletal metastases of the spine and pelvis: gradient echo opposed-phase MRIcompared with bone scintigraphy

Opposed-phase gradient eho (GRE) MRI at 0.5 T was compared with T1-weighted GRE MRI and bone scintigraphy regarding the detection of malignant bone marrow infiltrates of the spine and pelvis. Seventeen control patients and 41 patients with suspected skeletal metastases were studied with plain and gadolinium-enhanced MRI. In the control group only a vertebral haemangiona showed contrast enhancement, while all metastases (confirmed histologically or by follw-up) were enhancing. Opposed-phase surface coil MRI showed a significantly higher contrast-to-noise ratio of 56 metastases than T1-weighted images. In 28 patients body coil opposed-phased MRI detectedmore metastatic foci of the spine and pelvis than did bone scintigraphy (84 vs 56). No scintigraphically visualised lesion was missed by MRI. In conclusion,body coil gadolinium-enhanced opposed-phase GRE MRI may be applied as a screning method for skeletal metastases of the spine and pelvis at intermediate field strengths. Correspondence to: K. Neumann     

Whole-body iodine-131 metaiodobenzylguanidine imaging for detection of bone metastases in patients with paraganglioma: comparison with bone scintigraphy

Iodine-131 metaiodobenzylguanidine (¹³¹I-MIBG) therapy is an effective treatment for patients with malignant paraganglioma for which surgical resection is not indicated. We performed high-dose ¹³¹I-MIBG therapy on two patients with malignant paraganglioma and multiple bone metastases. The bone metastases were diagnosed by magnetic resonance imaging (MRI). Metastatic bone lesions were evaluated by whole-body ¹³¹I-MIBG imaging and bone scintigraphy. Whole-body ¹³¹I-MIBG imaging showed extensive metastatic bone lesions, whereas conventional bone scintigraphy did not. There was a remarkable discrepancy between ¹³¹I-MIBG imaging and bone scintigraphy in the diagnosis of metastatic bone lesions of malignant paraganglioma in our two patients. High-dose ¹³¹I-MIBG imaging may detect early stages of bone metastases, compared with bone scintigraphy, in patients with malignant paraganglioma.     

The usefulnes of99mTc-HMPAO-labeled leukocyte scintigraphy in the diagnosis of skeletal metastases of cancers

The usefulness of bone marrow scintigraphy with 99mTc-HMPAO-labeled leukocytes (leukocyte bone marrow scintigraphy) in the diagnosis of skeletal metastases of cancers was investigated in 70 lesions in 27 patients with various types of cancer. The final diagnosis of skeletal metastases was based on one or more criteria consisting of histological confirmation, typical findings of metastases by bone radiograph, CT and MRI, or progressive swellings of the lesions with severe pain due to nerve compression. Of the 70 lesions, 55 were finally diagnosed as metastases, and 15 as benign lesions. Leukocyte bone marrow scintigraphy showed photopenic defects in 52 of the 55 metastatic lesions (sensitivity 95%), and the remaining 3 negative lesions were found positive for metastases by MRI. In contrast, MRI could evaluate only 39 of the 55 lesions because 16 lesions in the ribs, scapula and sternum were not visualized. Of these 39 lesions, MRI showed positive findings for metastases in 33 (sensitivity 85%), and negative findings in 6 with photopenic defects found by leukocyte bone marrow scintigraphy. Of the 15 benign lesions, 3 were false positive for metastases on leukocyte bone marrow scintigraphy (specificity 80%). We conclude that 99mTc-HMPAO-labeled leukocyte bone marrow scintigraphy may be useful in the diagnosis of skeletal metastases of cancers, particularly when MRI fails to evaluate the lesions.     

A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture

Objective. To determine the accuracy of MRI in the assessment of the radiographically occult scaphoid fracture. Design. This prospective study compared the sensitivity and specificity of MRI for detection of radiographically occult scaphoid fractures with bone scintigraphy (BS), the currently accepted imaging modality of choice. Consecutive patients with clinical signs of a scaphoid injury but no evidence of fracture on plain radiographs at presentation and after 7–10 days were evaluated by MRI and BS. All images were reported in masked fashion and the sensitivities and specificities of the imaging modalities determined. All patients with a scaphoid fracture demonstrated by MRI or BS were followed for at least a year after injury. Patients. Forty-three subjects (aged 12–74 years) had both MRI and BS carried out on average 19 days from the injury date. Results and conclusions. Six patients (14%) had scaphoid waist fractures. There were other bony injuries in a further six. In 40 patients there was agreement between the BS and MRI findings. In three cases there was discrepancy between the imaging modalities; in all three MRI was found to be the more sensitive and specific. MRI could become the investigation of choice for this injury.     

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.     

MRI与骨扫描诊断前列腺癌骨转移的比较

目的 通过比较MRI与核素骨扫描对前列腺癌骨转移的诊断,以选择最优的无创成像手段来明确前列腺癌的分期。材料与方法 回顾性分析2011年1月-2013年6月经病理证实为前列腺癌的病人252例。年龄57~88岁,平均年龄（73±7.98）岁,分别获取并比较MRI和骨扫描对前列腺癌骨转移诊断的敏感度、特异度、准确度、阳性预测值（PPV）、阴性预测值（ＮＰＶ）。结果 54例病人诊断为骨转移（成骨性骨转移48例,混合性骨转移6例）。80%（41/54）的前列腺癌骨转移病人的前列腺特异性抗原（PSA）>50 ng/mL,而92%（182/19８）的前列腺癌无骨转移病人的PSA<50 ng/mL。MRI诊断前列腺癌骨转移的敏感度、特异度、准确度、PPV、NPV分别为85.1%、100%、96.8%、100%、96.1%;全身骨扫描诊断前列腺癌骨转移的敏感度、特异度、准确度、PPV、NPV分别为92.5%、84.3%、86.1%、61.7%、97.6%。结论 MRI对前列腺癌骨转移的诊断特异度、准确度及PPV较高,骨扫描的敏感度较高。MRI与骨扫描可以实现优势互补,利于前列腺癌的准确临床分期。     

Omission of bone scanning according to staging guidelines leads to futile therapy in non-small cell lung cancer

The leading European and American professional societies recommend that bone scans (BS) should be performed in the staging of lung cancer only in those patients with bone pain. This prospective study investigated the sensitivity of conventional skeletal scintigraphy in detecting osseous metastases in patients with lung cancer and addressed the potential consequences of failure to use this method in the work-up of asymptomatic patients. Subsequent to initial diagnosis of non-small cell lung cancer, 100 patients were examined and questioned regarding skeletal complaints. Two specialists in internal medicine decided whether they would recommend a bone scan on the basis of the clinical evaluation. Skeletal scintigraphy was then performed blinded to the findings of history and physical examination. The combined results of magnetic resonance imaging (MRI) of the vertebral column, positron emission tomography (PET) of skeletal bone and the subsequent clinical course served as the gold standard for the identification of osseous metastases. Bone scintigraphy showed an 87% sensitivity in the detection of bone metastases. Failure to perform skeletal scintigraphy in asymptomatic patients reduced the sensitivity of the method, depending on the interpretation of the symptoms, to 19–39%. Without the findings of skeletal scintigraphy and the gold standard methods, 14–22% of patients would have undergone unnecessary surgery or neoadjuvant therapy. On this basis it is concluded that bone scans should not be omitted in asymptomatic patients.     

Whole-body magnetic resonance imaging for detecting bone metastases: comparison with bone scintigraphy

Purpose

The aim of the study was to assess the reliability of whole-body magnetic resonance imaging (WB-MRI) in detecting skeletal metastasis and to compare the results with those of bone scintigraphy (BS).

Materials and methods

Thirty-three patients (21 women, 12 men, median age 58 years, range 27–78) were enrolled. Histological proof of malignancy was obtained in all cases. The primary tumour was unknown in 1 patient. BS and WB-MRI were performed as staging procedures in 15 patients, during the follow-up in 6 and to investigate pain in 9 and neurological symptoms in 3. Bone metastases were recorded for 8 different skeletal segments (ribs, skull, cervicothoracic spine, lumbosacral spine, clavicle-scapula-sternum, pelvis, upper extremities and lower extremities) in all patients, for a total of 264 examined areas.

Results

Bone metastases were detected in 18 patients (55%). In 15/33 patients, WB-MRI and BS were concordantly negative. BS revealed focal metastatic uptake in 72%, whereas WB-MRI was positive in 89%. Results differed in seven patients. WB-MRI was positive but BS was negative in five cases. Two patients with negative WB-MRI had focal and intense uptake in the ribs on BS. Out of 264 examined areas, bone metastases were detected in 34 (13%). WB-MRI revealed tumour spread in 26/34 areas (76%) and BS in 21/34 areas only (62%).

Conclusions

WB-MRI is a reliable method for screening patients with suspected skeletal metastases, although BS still remains a useful tool. WB-MRI is also advantageous because it reveals extraskeletal and soft tissue metastases.     

全身MRI与核素骨扫描对骨转移瘤诊断价值的对照研究

目的 评价全身MRI对骨转移瘤的诊断价值.方法 对30例经病理证实的恶性肿瘤患者在2周内分别进行伞身MRI及核素骨显像(BS),采取临床资料同常规MRI、CT等多种影像资料结合分析,辅以必要的随访复查为"金标准",分别以30例患者和270个部位为单位进行分析.使用McNemar检验比较两者对骨转移瘤诊断的敏感度、特异度.结果 30例患者中,"金标准"诊断27例患者存在骨转移,全身MRI检出25例,2例假阴性,无假阳性患者;BS检出27例阳性患者,其中2例为假阳性.以病例为单位,两者的敏感度均为92.6%(25/27),特异度分别为100%(3/3)及33.3%(1/3).ROC曲线下面积分别为0.9630及0.6296,差异无统计学意义(P>0.05).以病灶部位为单位统计显示全身MRI的敏感度、特异度分别为90.8%(108/119)、98.0%(148/151),高于骨扫描的70.6%(84/119)、90.7%(137/151)(P值均<0.01).全身MRI的ROC曲线下面积为0.9438,大于BS的0.8066(P<0.01).全身MRI同时发现3例患者存在脑转移,4例患者存在肺转移,4例患者存在肝转移.结论 全身MRI对骨转移瘤的综合诊断能力较Bs好,具有一定的临床应用价值.

Abstract：

Objective The aim of the study was to evaluate the reliability of whole-body MRI(WBMRI)in detecting osseous metastases.Methods Thirty patients verified with malignant tumor by histology were enrolled.All the patients underwent WB-MRI and bone scintigraphy(BS)with a two week interval.Clinical information,conventional MRI and CT images,and follow-up data were collected as gold standard for the diagnosis of bone metastases.The data of 30 patients and 270 segments as study unit respectively were analyzed.The sensitivity and specificity between WB-MRI and BS were compared with McNemar test.Resuits Bone metastases were confirmed in 27 of 30 patients by gold standard.Twenty-five patients with bone metastases were detected by WB-MRI and no false-positive cases.Twenty-seven patients with bone metastases were Nund by BS but having two false-positive oases.With patients as study unit,the diagnostic sensitivity of WB-MRI and BS were both 92.6%(25/27)and the specificity were 100%(3/3)and 33.3%(1/3),respectively.The area under ROC curve of WB-MRI and BS were 0.9630 and 0.6296,respectively(P>0.05).With segments as study unit,119 bone metastases segments were confirmed.The diagnostic sensitivity of WB-MRI and BS were 90.8%(108/119)and 70.6%(84/119)(P<0.01),while the specificity were 98.0%(148/151)and 90.7%(137/151),respectively(P<0.01).The area under ROC curve of WB-MRI and BS were 0.9438 and 0.8066.The former was obviously higher than the latter(P<0.01).Meauwhile.by WB-MRI,3 cases coexisting with brain metastases,4 cases with lung metastases,and 4 cases with hepatic metastases were found.Conclusion WB-MRI was a good tool for screening osseous metastases.     

Diagnostic accuracy of bone metastases detection in cancer patients: Comparison between bone scintigraphy and whole-body FDG-PET

18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has become widely available and an important oncological technique. To evaluate the influence of PET on detection of bone metastasis, we compared the diagnostic accuracy of PET and conventional bone scintigraphy (BS) in a variety of cancer patients. METHODS: Consecutive ninety-five patients with various cancers, who received both PET and BS within one month, were retrospectively analyzed. A whole-body PET (from face to upper thigh) and a standard whole body BS were performed and these images were interpreted by two experienced nuclear medicine physicians with and without patient information using monitor diagnosis. Each image interpretation was performed according to 8 separate areas (skull, vertebra, upper limbs, sternum and clavicles, scapula, ribs, pelvis, and lower limbs) using a 5-point-scale (0: definitely negative, 1: probably negative, 2: equivocal, 3: probably positive, 4: definitely positive for bone metastasis). RESULTS: Twenty-one of 95 patients (22.1%) with 43 of 760 areas (5.7%) of bone metastases were finally confirmed. In untreated patients, 12 of 14 bone metastasis positive patients were detected by PET, while 9 of 14 were detected by BS. Three cases showed true positive in PET and false negative in BS due to osteolytic type bone metastases. In untreated cases, PET with and without clinical information showed better sensitivity than BS in patient-based diagnosis. For the purpose of treatment effect evaluation, PET showed better results because of its ability in the evaluation of rapid response of tumor cells to chemotherapy. Out of 10 cases of multiple-area metastases, 9 cases included vertebrae. There was only one solitary lesion located outside of FOV of PET scan in the femur, but with clinical information that was no problem for PET diagnosis. CONCLUSION: Diagnostic accuracy of bone metastasis was comparable in PET and BS in the present study. In a usual clinical condition, limited FOV (from face to upper thigh) of PET scan may not be a major drawback in the detection of bone metastases because of the relatively low risk of solitary bone metastasis in skull bone and lower limbs.     

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.     

Unusual metastatic chondrosarcoma detected with bone scintigraphy

A case is presented of a scapular chondrosarcoma which showed intense uptake of Tc99m MDP in the primary tumour and in pleural and osseous metastases. Additionally, there was intense visualization of the malignant pleural effusion. The bone scintigraphy correctly diagnosed the extent of the involvement. This finding is unusual because chondrosarcomas in such a disseminated state are relatively rare.     

MR detection of iliac bone marrow involvement by malignant lymphoma with various MR sequences including diffusion-weighted echo-planar imaging

OBJECTIVE: To assess the diagnostic accuracy of MR imaging for detecting bone marrow infiltration by malignant lymphoma. PATIENTS AND DESIGN: Fifty-three patients with malignant lymphoma underwent MR imaging and bone marrow biopsy. In 80 iliac crests of the 53 patients (13 positive specimens in 9 patients and 67 negative specimens in 44 patients), biopsy results and the signal intensity characteristics were compared. MR sequences included T1-weighted SE, T2-weighted FSE with fat suppression, FSE STIR, and diffusion-weighted EPI with fat suppression at 1.5 T. RESULTS AND CONCLUSIONS: To detect lymphoma infiltration, T1-weighted SE had the highest sensitivity (92%) and diffusion-weighted EPI with fat suppression and FSE STIR had the highest specificity (92.5% and 92%, respectively). A combination of T1-weighted SE and FSE STIR yielded the highest sensitivity and specificity (85% and 97%, respectively). A combination of T1-weighted SE and FSE STIR sequences seems to be the current choice of imaging protocol for detecting bone marrow infiltration by malignant lymphoma.