Magnetic resonance imaging versus bone scintigraphy in suspected scaphoid fracture

Magnetic resonance imaging (MRI) has become increasingly useful in the evaluation of musculoskeletal problems, including those of the wrist. In patients with a wrist injury, MRI is used mainly to assess vascularity of scaphoid non-union. However, the use of MRI in patients in the acute phase following carpal injury is not common. Three-phase bone scintigraphy is routinely performed from at least 72 h after injury in patients with suspected scaphoid fracture and negative initial radiographs. We evaluated MRI in this patient group. The bone scan was used as the reference method. Nineteen patients were included. Bone scintigraphy was performed in all 19 patients, but MRI could be obtained in only 16 (in three patients, MRI was stopped owing to claustrophobia). In five patients, MRI confirmed a scintigraphically suspected scaphoid fracture. In one patient, a perilunar luxation, without a fracture, was seen on MRI, while bone scintigraphy showed a hot spot in the region of the lunate bone, suspected for fracture. This was confirmed by surgery. In two patients, a hot spot in the scaphoid region was suspected for scaphoid fracture, and immobilization and employed for a period of 12 weeks. MRI was negative in both cases; in one of them a scaphoid fracture was retrospectively proven on the initial X-ray series. In another two patients, a hot spot in the region of MCP I was found with a negative MRI. In both, the therapy was adjusted. In the remaining six patients, both modalities were negative. We conclude that in the diagnostic management of patients with suspected scaphoid fracture and negative initial radiographs, the use of MRI may be promising, but is not superior to three-phase bone scintigraphy.     

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。     

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     

A comparison of pulse sequences in the detection of post-traumatic bone marrow abnormalities at low field strength MRI

Objective and patients. One hundred and forty-one patients with recent joint trauma, aged 12–71 years, were imaged on a 0.2-T dedicated MRI system and evaluated for bone bruises. The most beneficial sequences were compared. Design. The diagnosis of post-traumatic bone marrow abnormalities was established in 20 of 141 patients on the basis of decreased signal intensity on T1-weighted SE and GRE sequences and increased signal intensity on T2-weighted TSE and fat-suppressed IRGE sequences. Signal changes within the bone marrow were evaluated and statistically correlated with normal bone. Results. The highest signal alteration was found on T1-weighted SE and GRE sequences, followed by IRGE, which detected smaller differences in signal intensity. T2-weighted TSE imaging showed the least contrast. The areas with bone marrow changes were approximately equal in size on T1-weighted SE and T2-weighted TSE sequences. The same areas depicted on IRGE and GRE sequences proved to be significantly larger (P<0.01). Conclusion. Using a 0.2-T dedicated system T1-weighted SE, T1-weighted GRE and IRGE sequences were most effective in detecting conspicuous bone marrow alteration, while the T2-weighted TSE sequence was inferior. GRE and IRGE imaging showed areas about 4 times larger depicting bone marrow changes. On suspicion of bone bruise, a protocol including GRE and IRGE pulse sequences could be most beneficial.     

The reliability of the 3-phase bone scan in suspected scaphoid fracture: an inter- and intraobserver variability analysis

In the diagnosis of scaphoid fracture, the dynamic phase of the radionuclide bone scan alone has been recommended as an early test. To evaluate the independent reliability of the dynamic and static phases of the 3-phase bone scan in this diagnosis, 3 examiners reviewed the 3-phase bone scans of a series of 60 patients with clinical signs of fracture of the carpal scaphoid and with negative or non-diagnostic initial radiographs. The interpretation was performed independently and without the benefit of additional data. The bone scans were reviewed after 1 year by the same observers. The results were analyzed using kappa statistics. The bone scan was suspicious of fracture of the scaphoid in 15 patients. Irrespective of training and experience, the kappa values of the dynamic bone scan between any 2 observers did not exceed 0.57. The kappa values increased significantly when the static phase of the bone scan was examined (> 0.81). The intraobserver variability showed a similar pattern. We conclude that in suspected scaphoid fracture, the dynamic phase of the radionuclide bone scan alone cannot be used as a reliable diagnostic approach because of the low inter- and intraobserver agreement in the interpretation, irrespective of the experience and training of the observer. Offprint requests to: M.M.C. Tiel-van Buul     

Desmoplastic fibroma of bone: MRI features

Desmoplastic fibroma of bone is a very rare benign tumor, which may be locally aggressive. In contrast to the well-documented radiological appearance, the literature on MR imaging features of this tumor is scarce. The MR imaging characteristics in our case are compared to those previously reported. Although there is a considerable overlap in the MR imaging features with other bone tumors, an interesting MR feature of desmoplastic fibroma is the presence of low to intermediate signal intensity foci on T2-weighted images, which radiographically does not correspond to calcifications. This feature may help narrow the differential diagnosis. Received: 24 May 1999 Revision requested: 30 June 1999 Revision received: 8 October 1999 Accepted: 14 October 1999     

MRI of bone marrow disorders

Four factors can be used in MR of bone marrow: fat–water distribution, artifacts induced by bone trabeculae, diffusion, and uptake of contrast media. Fat–water is imaged using T1-weighted spin-echo, short tau inversion recovery (STIR), and fast STIR, in- and out-of-phase gradient echo, and fat pre-saturation sequences; bone trabeculae by gradient echo with long TE; diffusion by single-shot spin-echo. The injection of contrast media is a more easy and efficient way to improve the specificity. The value and limitations of those sequences are discussed in marrow replacements (metastases, lymphoma, leukemia) and in myeloid hyperplasia or depletion.     

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.     

Sacral hydatidosis: value of MRI in the diagnosis

We present a case of primary hydatid disease of the sacrum. The diagnosis was made on MR imaging obtained to evaluate the spine for recurrent disc disease. The patient had previously undergone laminectomy elsewhere for L4–5 radiculopathy.Ultrasound-guided aspiration and visualisation of scolices confirmed the diagnosis. No other site of involvement was found.     

骨扫描与肿瘤标志物联检在骨转移诊断中的应用进展

骨骼是晚期恶性肿瘤最常见的扩散转移部位之一.由骨转移引发的骨相关事件可以明显影响晚期肿瘤病人的生活质量和临床转归.骨扫描目前仍然是诊断骨转移的首选检查方法.尽管骨扫描具有高度的敏感性,但其特异性仍较低,如与不同癌症的相关肿瘤标志物联检,可明显提高骨扫描的诊断特异性,还可不同程度地提高其诊断的敏感性和准确性.就骨扫描与肿瘤标志物联检在骨转移诊断中的应用及其潜在的临床价值予以综述.     

隐匿性骨折的MRI诊断

隐匿性骨折的诊断是当前临床骨外科诊疗过程中的难点之一,很容易造成漏诊、误诊,引起一些不必要的医疗纠纷。MRI检查由于具有高的软组织分辨率、多轴面、多序列成像及无辐射特点,在隐匿性骨折的诊断,尤其是早期诊断中占有很重要的价值。     

Bone scintigraphy and magnetic resonance imaging after transtrochanteric rotational osteotomy

Objective. To assess the ability of bone scintigraphy and magnetic resonance imaging (MRI) to predict the outcome of transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH). Design. This study was a prospective evaluation of imaging techniques. Patients and methods. MRI and bone scintigraphy were performed on 20 hips in 18 patients at 3 months after TRO. The radiographic findings at 3 months after TRO, and the MRI and bone scintigraphic findings, were compared with the radiographic findings at final follow-up (mean 39 months). Results and conclusions. On MRI a low-intensity area or a low-intensity band in the new weight-bearing area extending over the acetabular edge on T1-weighted images was related to the presence of collapse on the radiographs at final follow-up. In hips with an area of absent activity in the new weight-bearing surface on bone scintigraphy, collapse was seen more frequently on radiographs at final follow-up than in hips without this feature. Bone scintigraphy was no more specific than radiography in predicting the outcome after TRO. We consider MRI to be superior to bone scintigraphy in predicting the occurrence of collapse, which is one of the major short-term problems after TRO. Received: 22 July 1997 Revision requested: 2 January 1998, 12 October 1998 Revision received: 3 March 1998, 23 December 1998 Accepted: 18 January 1999     

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.     

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。     

Treated plasma cell lesions of bone with MRI signs of response to treatment: unexpected pathological findings

Two cases of treated plasma cell lesions of bone are reported for which contrast-enhanced MRI had suggested necrosis, based on lack of enhancement after gadolinium injection, and in which pathologic examinations revealed the presence of extensive viable neoplastic tissue. These cases highlight the need for cautious interpretation of contrast-enhanced MRI signs of response to treatment and inactivity of lesions in the setting of plasma cell neoplasms.     

MRI gadolinium enhancement of bone marrow: age-related changes in normals and in diffuse neoplastic infiltration

 Objective: To quantify gadolinium-related enhancement in the bone marrow of the spine in normals and in patients with homogeneous diffuse malignant bone marrow infiltration. Design and patients: The patients consisted of two groups: group 1 comprised 94 healthy adults (18–86 years) without bone marrow disease and group 2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n=20) or breast carcinoma (n=10). All patients received intravenous gadopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast signal intensity (SI) on T1-weighted spin-echo (SE) images (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI) and the percentage SI increase was calculated. The results were confirmed by bone marrow biopsy (n=20) and clinical parameters (n=10). Dynamic contrast-enhanced studies using a spoiled gradient-recalled-echo (GRE) sequence (TR/TE/α: 68 ms/6 ms 75°) were performed in 10 controls with normal bone marrow. Results and conclusion: Contrast material enhancement in healthy persons can vary greatly (range 3–59%, mean 21%, SD 11%). With increasing age there is a significant decrease in contrast enhancement (Pearson’s correlation, P<0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20–50 vol%) and high-grade (biopsy >50 vol%) diffuse malignant bone marrow infiltration was significantly higher than in normals (mean 67%, SD 34%, P<0.001). Low-grade (biopsy <20 vol%) diffuse malignant bone marrow infiltration can not be assessed by non-enhanced T1-weighted SE images or Gd-DTPA application. In conclusion, contrast material enhancement in healthy persons can vary greatly and is dependent on age, while intermediate-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed with SI measurements.     

MRI of degenerative bone marrow lesions in experimental osteoarthritis of canine knee joints

 Objective. The objective of this study was to determine the value of MRI in the detection of degenerative bone marrow abnormalities in an animal osteoarthritis model. Design. In 10 dogs with experimentally induced unilateral osteoarthritis of the knee, MRI was performed using two-dimensional spin-echo (2D-SE) and three-dimensional gradient-echo (3D-GE) imaging. Contrast enhanced T1-weighted 2D-SE sequences were also obtained after injection of gadolinium-DTPA. The results were compared with the gross and histopathologic findings and with radiography. Results. Histopathologic specimens revealed 21 osteosclerotic lesions and 5 intraosseous cysts. On 2D-SE images, 24 of 26 lesions were detected, while 21 of 26 lesions were identified on 2D-GE sequences. Radiography, including conventional tomography, demonstrated 9 of 26 lesions. Regardless of the sequence weighting, all osteosclerotic lesions appeared hypointense on MRI. Signal loss in bone sclerosis resulted primarily from the reduction of intact fat marrow, the increased bone density being of secondary importance. Quantitative signal analysis allowed approximate estimation of the grade of sclerosis. On postcontrast images, sclerotic bone remained hypointense, although significant but non-specific enhancement relative to the normal fat marrow was observed. The extent of contrast enhancement did not correlate with the grade of osteosclerosis. All five cysts were readily diagnosed by MRI. Cysts displayed either central or marginal contrast enhancement within their cavities. Conclusions. MRI provides a sensitive method for the diagnosis of osteoarthritic bone abnormalities, allowing their differentiation from most non-degenerative subarticular lesions.     

Pasteurized intercalary autogenous bone graft: radiographic and scintigraphic features

Objective. Pasteurized autogenous bone graft sterilized at a low temperature (60°C) is one option for reconstruction after resection of bone and soft tissue tumors. The purpose of this investigation was to assess the normal and abnormal radiographic and scintigraphic findings of pasteurized intercalary autogenous bone graft after resection of bone and soft tissue sarcomas. Design. This was a retrospective evaluation of the radiography and bone scintigraphy findings in patients after treatment of bone and soft tissue sarcomas using an intercalary pasteurized autogenous bone graft. Patients. Among 10 consecutive patients, eight had intercalary grafts, and they constitute the subjects of this study. All available radiography and bone scintigraphy findings were reviewed for the healing process and the possibility of complications. Results and conclusions. Healing and incorporation of the graft were observed in five patients during the follow-up, but the other three did not heal satisfactorily. Rapid incorporation of pasteurized autogenous bone graft can be demonstrated by means of radiography and bone scintigraphy. Received: 21 December 1999 Revision requested: 16 February 2000 Revision received: 9 March 2000 Accepted: 14 March 2000