Occult epiphyseal bone abscess: Lessons for the unwary

Two male children presented with increasing pain in the right knee and constitutional symptoms. Biochemical markers of inflammation were elevated. Plain radiography was reported as normal and bone scintigraphy was consistent with synovitis of the right knee in the first case. The second child underwent aspiration of the knee with drainage of turbid fluid 1 week after antibiotics. Slow response to therapy led to MRI and CT scanning in the second child, revealing an epiphyseal abscess. Review of the scintigraphic studies in the first child raised the possibility of osteomyelitis of the distal right femur. Further imaging was undertaken with MRI and CT scanning confirming an epiphyseal bone abscess. Failure of diagnosis of an epiphyseal bone abscess by combined plain radiography and scintigraphy has not previously been reported and provides a number of valuable lessons.     

Detection of malignant bone marrow involvement with dynamic contrast-enhanced magnetic resonance imaging.

BACKGROUND: The purpose of this study was to evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (dMRI) in detecting bone marrow involvement in cancer patients. PATIENTS AND METHODS: We studied 50 consecutive patients with histologically confirmed malignant dissemination to the bone marrow, using dMRI of the lumbosacral spine. Time-signal intensity curves were generated from regions of interest (ROIs) obtained from areas of obvious bone marrow disease (group B). In 16 patients from group B with focal disease, ROIs were also placed on areas with apparently normal bone marrow on static magnetic resonance images (group C). Twenty-two patients with no history of malignancy were used as a control group (group A). Wash-in (WIN) and wash-out (WOUT) rates, time to peak (TTPK), time to maximum slope (TMSP) values and WIN/TMSP ratios were calculated for each patient. Mean values for the three groups were compared statistically. Six patients from group B had follow-up dMRI after chemotherapy: four patients achieved a clinical partial response and two had resistant disease. RESULTS: A significant difference was found between groups A and B for all values. Between groups A and C, in spite of the similar static MRI appearance, all values were significantly different. Between groups B and C, a significant difference was found for WIN, WOUT rates and WIN/TMSP ratio. Follow-up dMRI data analysis correlated well with clinical staging. CONCLUSIONS: dMRI can distinguish normal from malignant bone marrow. It may identify malignant bone marrow infiltration in patients with negative static MRI and serve as both a diagnostic and prognostic tool for patients with bone marrow malignancies.     

Aneurysmal bone cyst of the temporal bone

Aneurysmal bone cyst (ABC) of the temporal bone is rare. The nature of the underlying disorder that converted into the ABC might, however, be difficult to ascertain on imaging as well as on histopathology. The unusual CT and MRI findings in a case of ABC of the temporal bone are presented. This had transdural intracerebral spread with a large component of solid enhancing matrix but no peripheral calcific rim. The patient was an adult of 45 years with a history of headache for more than 1 year.     

Imaging of tarsal navicular stress injury with a focus on MRI: A pictorial essay

Predominantly diagnosed in athletes, stress fracture of the tarsal navicular is becoming increasingly recognised by clinicians as a cause of midfoot pain. Delayed diagnosis can increase the significant morbidity associated with this condition. Consequently the role of MRI is increasing, given the potential to identify a stress reaction in the navicular prior to the development of a discrete stress fracture. It is necessary for radiologists to be familiar with the typical and atypical appearances of this important condition.     

Subperiosteal aneurysmal bone cyst with associated bone marrow oedema: An unusual appearance

A case of a subperiosteal aneurysmal bone cyst with adjacent bone marrow oedema is presented. Aneurysmal bone cysts have been well documented in the published literature; however, relatively few have been observed in a subperiosteal location, and associated bone marrow oedema in the absence of a demonstrable pathological fracture is a rare finding. Aneursymal bone cyst should be considered in the differential diagnosis of subperiosteal bone lesions and may be associated with bone marrow oedema.     

Magnetic resonance imaging of bone marrow versus bone marrow biopsy in malignant lymphoma

Bone marrow involvement is a frequent finding in malignant lymphoma. Bone marrow biopsy of the posterior iliac crest is routinely performed for staging. Abnormal magnetic resonance imaging (MRI) signals of bone marrow was also reported to be indicative of bone marrow involvement. This study included 60 patients with malignant lymphoma. Unilateral bone marrow biopsy of the posterior iliac crest was performed. MRI of lumbar spine was studied within 24 hours of bone marrow biopsy. 22 healthy controls were used for the detection of MRI objectivity during visual evaluation. In 83% of patients (50/60), biopsy and MRI results agreed completely. In two patients, histologic sections failed to show any evidence of bone marrow involvement despite abnormal MRI signals suggestive of involvement. In three patients, MRI was completely normal despite biopsy proven bone marrow infiltration. False negativity (3/60) and false positivity (2/60) rates were very low. Negative biopsy findings with positive or equivocal MRI results should not exclude bone marrow involvement and needs further evaluation with bilateral or guided biopsy. Thus, we conclude that MRI of bone marrow is a fairly sensitive, noninvasive modality and might be of potential value in detecting bone marrow infiltration in malignant lymphoid neoplasms which can be utilized as a useful adjunct to standard staging procedures.     

Fluid-fluid levels in a simple bone cyst on magnetic resonance imaging

An unusual case is presented here of simple bone cyst (SBC) with fluid-fluid levels on MR and cementum-like substance on microscopy in an atypical location in the distal femur. Fluid-fluid levels are commonly described in the literature within aneurysmal bone cysts, giant cell tumour, chondroblastomas and telangiectatic osteosarcomas, but a literature review revealed only one reported case with multiple fluid levels occurring in a simple bone cyst on MRI. A cementum-like matrix is diagnostic of SBC and is seen in ± 10% of cases.     

骨肿瘤的MR灌注和弥散加权成像研究

Objective:MR-PWI and MR-DWI were supplementary functional methods to differentiate benign from malignant bone tumors.The aim of this study was to assess the diagnostic potential of MR-PWI conjunction with MR-DWI in differentiating benign from malignant bone tumors.Methods:MR-PWI and MR-DWI were performed on 39 patients by using a 1.5 T MR imager.Perfusion imaging was started with GRE-EPI sequence as soon as che bolus administration commenced.With b value as 300 s/mm2,diffusion imaging was performed with SE-EPI sequence.mype of TIC,peak enhancement,steepest slope,signal difference between 2 baselines and ADC were compared between benign and malignant bone tumors.The data were analyzed with soft-ware(SPSS,version 13.0).Subjective overall pefrormance of two techniques was evaluated with Receiver Operating Characteristic(ROC)analysis.Resuits:1.MR-PWI:(1)The Patterns of TIC of most benign bone tumors(17/21)were type Ⅰ and Ⅱ,and all malignant bone tumors were type Ⅲ and Ⅳ.(2)There were significant differences in peak enhancemenl(17.52±2.37 vs.52.42±5.74)%,steepest slope(4.69±2.84 vs.9.63±4.05)%/S and signal difference between 2 baselines(6.87±3.34 vs.31.75±11.0g)% between benign and malignant groups.And their diagnosis accuracy was 82.1%,79.5% and 87.2%,respectively.(3).4 highly vascularized benign bone tumors were mistaken in diagnosis as malignant ones according to their perfusion characteristics.2.MR-DWI:There was significant difference between ADC of benign and malignant groups[(1.86±0.38)vs.(1.44±0.26)] ×10-3 mm2/s when b value was 300 s/mm2.The diagnosis accuracy was 79.5% when ADC value less than 1.63×10-3 mm2/s was considered as malignant ones.3.The diagnosis accuracy of MR-PWI and MR-DWI were 89.7% and 79.5%.respectively.Conclusion:MR-PWI is lhe better valuable technique than MR-DWI in differentiation benign from malignant bone tumors.To suspicious highly vascularized bone tumors.MR-PWI combining with MR-DWI lead to higher diagnosis accuracy.     

Bone changes in tuberous sclerosis mimicking metastases

Sclerotic and lytic bone changes of tuberous sclerosis (TS) can mimic bone metastases. We report a case of bone metastases from bronchogenic carcinoma in a patient with TS bone changes. Bone scintigraphy and magnetic resonance imaging are useful in distinguishing the TS bone lesions from bone metastases.     

Magnetic Resonance Imaging in Patients with Bone Marrow Disorders

Magnetic resonance imaging (MRI) provides a non-invasive means to evaluate a large fraction of marrow in less than one hour. Marrow disorders produce non-specific changes in marrow signal intensities which primarily reflect changes in proportions of fat and cellular elements. The pattern of these signal changes narrows the differential diagnosis, and the combination of these features with the clinical context allows interpretations which are clinically useful in many ways. These include: I) the diagnosis of avascular necrosis (and its distinction from other causes of joint pain), 2) detection of osteomyelitis, 3) differential diagnosis of hypo-plastic disorders, 4) staging of lymphomas and myeloma, 5) selection of patients for autolo-gous bone marrow transplant, 6) objective measures of marrow response to therapy, 7) detection of leukemic transformation, and 8) improved detection of marrow disease (primary or secondary) in patients with otherwise unexplained bone pain.     

SPECT核素骨显像联合MRI增强成像鉴别诊断骨转移瘤100例临床观察

目的评估SPECT核素骨显像（以下简称ECT）联合磁共振（MRI）增强成像检查鉴别及确诊骨转移瘤的价值,并探讨两者检查的优劣势,以便优势互补,提高诊断率。方法选择100例先行骨显像后行MRI增强检查的患者,分别阅读各自发现的病灶,再两者对比阅读发现的病灶,甚至随访直到确诊。验证两者结合检查对提高诊断率的可行性。结果ECT核素骨显像的准确性93％,MRI的准确性为99％,两者比较,差异有统计学意义（P〈0．05）。结论联合应用ECT及MRI增强成像检查,可以提高骨转移瘤的早期诊断率及鉴别诊断。     

大脑胶质瘤病的MRI及MRS研究(英文)

目的回顾性分析大脑胶质瘤病磁共振成像(MRI)及磁共振波谱(MRS)特点,以探讨其对本病诊断的临床价值。方法综合7例患者的临床表现、影像学特点及病理诊断,均符合大脑胶质瘤病诊断标准。常规行 SE 序列平扫及增强。其中3例行 MRS 研究,二维多体素、点分辨法(PRESS)、TE 144ms。结果所有病例均侵犯2个脑叶或以上。病变区呈长 T_2、稍长 T_1异常信号,受累区脑组织肿胀,占位效应轻。增强扫描3例见小结节或片状强化,4例无明显强化。3例 MRS 表现均有不同程度 NAA 降低,Cho 上升,Cho/Cr 和 Cho/NAA 的比值上升。结论 MRI 是目前诊断大脑胶质瘤病的首选影像学方法,MRS 对于鉴别诊断有较大价值。     

大脑胶质瘤病的MRI及MRS研究

目的回顾性分析大脑胶质瘤病磁共振成像(MRI)及磁共振波谱(MRS)特点,以探讨其对本病诊断的临床价值。方法综合7例患者的临床表现、影像学特点及病理诊断,均符合大脑胶质瘤病诊断标准。常规行SE序列平扫及增强。其中3例行MRS研究,二维多体素、点分辨法(PRESS)、TE144ms。结果所有病例均侵犯2个脑叶或以上。病变区呈长T2、稍长T1异常信号,受累区脑组织肿胀,占位效应轻。增强扫描3例见小结节或片状强化,4例无明显强化。3例MRS表现均有不同程度NAA降低,Cho上升,Cho/Cr和Cho/NAA的比值上升。结论MRI是目前诊断大脑胶质瘤病的首选影像学方法,MRS对于鉴别诊断有较大价值。     

Transient bone marrow oedema: A variant pattern of sacral insufficiency fractures

A 71-year-old woman presenting with severe low back pain was found to have a large oval area of increased sacral uptake on Tc-99m MDP scan, with corresponding T1-hypointense and T2-hyperintense areas on magnetic resonance (MR) images, highly suggestive of malignancy. Open biopsies showed only callus formation. The patient responded clinically to conservative measures, with twice-repeated follow-up Tc-99m MDP and MR scans documenting resolution of transient bone marrow oedema. We suggest that this form of marrow oedema represents a variant pattern of sacral insufficiency fractures.     

Giant myxoinflammatory fibroblastic sarcoma with bone invasion:a very rare clinical entity and literature review

Myxoinflammatory fibroblastic sarcoma （MIFS） is a rare low-grade, malignant soft tissue tumor that is usually observed in the extremities of adult patients. Magnetic resonance imaging findings for this tumor type have rarely been reported. We report a case involving the distal left femur of a middle-aged man and tumoral invasion of the bone, which, to our knowledge, has been previously described only once. He was treated with distal femoral tumor resection and reconstruction with a modular prosthesis. Histopathologic diagnosis confirmed MIFS. We reviewed literature of the diagnostic imaging and bone invasion findings associated with this tumor type.     

MRI: Imaging of stomach

The study is to determine the optimal MRI bowel preparation regime for visualization of the stomach anatomy. Eight healthy volunteers were asked to take water, 75% barium and blueberry juice. The image quality and tolerance of different stomach distension regime were evaluated. Blueberry juice gave the best distension, but the signal intensity was not very homogeneous. Taking into account the image quality, tolerability and adverse effects, it is concluded that water is the most desirable oral contrast for MR stomach imaging.