髋部疼痛常见病的磁共振表现

目的:探讨髋部疼痛病因的MRI影像学表现与鉴别诊断,为正确诊断髋部疼痛提供参考依据。方法:收集我院2005年8月～2009年7月期间,以髋部局部疼痛为主要临床症状的325例患者MRI资料。回顾性分析导致髋部局部疼痛的发病部位,病因及其MRI表现,探讨MRI对髋部疼痛的鉴别诊断价值。结果:引起髋部局部疼痛病因可来源于多个部位,包括骨盆、骶髂关节、腰椎等病变以及腹壁、泌尿生殖道、腹膜后间隙病变。其致病原因亦复杂多变,包括肌肉、肌腱软组织损伤,软骨损伤,关节脱位,骨折,梨状肌综合症,髋部弹响综合症,感染,关节游离体,骨性关节炎,股骨头无菌坏死,骨肿瘤,软组织肿瘤,泌尿系结石及椎间盘突出等多种疾病。结论:成人髋关节疼痛可由多种不同病因引起,可以直接与髋关节有关,也可以与髋关节周围结构有关,甚至与髋关节无关的结构如腰椎,腹膜后疾病。对于髋部疼痛,应根据临床表现选择适当影像学检查,综合考虑各种病因进行诊断。     

Contribution of fetal MR imaging in the evaluation of cerebral ischemic lesions

BACKGROUND AND PURPOSE: Little is known about the different patterns of fetal cerebral ischemic lesions at MR imaging. Our purpose was to evaluate the contribution of MR imaging in the evaluation of such lesions by correlating the results with ultrasonography (US) and neurofetopathologic (NFP) findings. METHODS: We examined 28 fetuses (mean, 28 weeks' gestation) with cerebral ischemic lesions on NFP examination. MR findings were correlated with US and NFP results with regard to the depiction of gyration and parenchymal abnormalities. RESULTS: MR imaging added to US findings in 24 cases by revealing lesions (gyration abnormalities, parenchymal lesions). These results were either overlooked during US (n = 16) or more extensive than expected with US (n = 8). MR findings were always confirmed by NFP. NFP yielded additional findings for 14 lesions that were overlooked during MR imaging (n = 4) or that were more extensive than expected with MR imaging (n = 10). T1-, T2-, and T2*-weighted MR patterns of different lesions (cavitations, gliosis, softening of the white matter, laminar necrosis, calcified leukomalacia, old hemorrhage) were identified. CONCLUSION: MR imaging is a valuable tool in the evaluation of fetal brain ischemia. The results of this study emphasize the role of the different sequences (T1-, T2-, T2*-weighted) required to detect fetal cerebral ischemic lesions. MR imaging is more accurate in the detection of small focal lesions than in the evaluation of diffuse white matter abnormalities.     

MR imaging of fetal brain

Magnetic resonance (MR) imaging was used to evaluate normal fetal intracranial anatomy in axial, coronal, and sagittal planes. The T1 and T2 weighted images (WI) of aborted fetuses of varying gestational ages were correlated with anatomic sections. In the premature fetus three distinct intensity zones were seen on MR that were not visualized on gross specimens. Unmyelinated white matter displays low intensity on T1 W1 and high intensity on T2 W1. Maturational changes of the brain were observed with advancing fetal age.     

MR imaging of fetal anomalies

MR imaging can be used to confirm the presence of most gross fetal anomalies detected by sonography in the second and third trimesters. The MR imaging findings in 25 cases of fetal anomalies first identified on sonography are illustrated.     

MR imaging appearance of frontal sinus barotrauma

We present the case of a flight passenger who experienced acute and severe headache during landing. MR imaging was performed because the patient had a history of vascular malformation and revealed an incidental venous angioma. A mass lesion in the frontal sinus, consistent with submucosal hematoma secondary to barotrauma, was thought to be the cause of the headache. To our knowledge, this is the first case of sinus barotrauma described in the radiologic literature and the first to describe the associated MR imaging findings.     

Lymphocytic vasculitis mimicking aggressive multifocal cerebral neoplasm: mr imaging and MR spectroscopic appearance

We present a case of multifocal enhancing lesions confined to the right cerebral hemisphere that mimicked diffuse neoplasm. MR spectroscopy revealed not only minimal elevation of the choline peak, but also marked elevation of the glutamate and glutamine peaks, findings that are more suggestive of an inflammatory process. Biopsy showed lymphocytic vasculitis, a rare variant of primary angiitis of the CNS. Following appropriate medical therapy, MR imaging demonstrated complete resolution of the lesions.     

Prosthetic testicle: appearance at MR imaging

The appearance of testicular prostheses on magnetic resonance (MR) images was studied in six patients with seven silicone implants: two with a fluid consistency and five that were solid. On T1-weighted images, both types of prosthesis demonstrated homogeneous low signal intensity; on T2-weighted images, the fluid implants had a uniformly low signal intensity, and the solid implants had a uniformly high signal intensity. Both prostheses created a chemical shift artifact on all imaging sequences owing to the difference in chemical composition of the prostheses and the surrounding tissue.     

Cranial postoperative site: MR imaging appearance

The ability to diagnose adverse postcraniotomy or postcraniectomy events is essential for proper postoperative care. The importance of identifying postoperative changes on CT has previously been shown. The purpose of this study is to assess the normal and abnormal MR changes that may be seen in the postcraniotomy/postcraniectomy period. The postoperative MR, CT, and medical records of 41 postcraniotomy patients and 26 postcraniectomy patients were reviewed. Reasons for choosing craniectomy over craniotomy included decompression, infected flap, bony involvement by tumor, and posttraumatic skull. In general, the postoperative normal anatomy was better seen with MR. Postoperative events included hemorrhage (two), infection (five), cyst formation (10), and recurrent tumor (five). In general, MR was found to be more useful than CT for the detection of hemorrhage and infection after craniotomy or craniectomy and for the proper localization of postoperative cysts. MR proved to be a useful method for following postoperative sites in the skull.     

Recurrent biliary cystadenoma: MR imaging appearance

The authors report the case of a 37-year-old woman with a biliary cystadenoma that mimicked a liver cyst. The magnetic resonance (MR) imaging features of this rare lesion were correlated with the pathologic findings, showing the potential of MR imaging for depicting and aiding in the diagnosis of biliary cystadenoma and its recurrence.     

Duodenal duplication cyst: MR imaging appearance

The MR imaging appearance of a duodenal duplication cyst is reported. MR imaging confirmed the diagnosis suggested by ultrasound and CT scans. Fat-suppressed MR imaging before and after oral administration of the positive contrast agent Gd-DTPA was able to define tissue planes between the lesion and adjacent structures, such as the head of the pancreas, providing useful information for an accurate surgical approach. To our knowledge this is the first reported case of a duodenal duplication cyst in an adult demonstrated by MR imaging. Received: 23 February 1998; Revision received: 22 July 1998; Accepted: 25 July 1998     

MR imaging of fetal abnormalities.

Our purpose was to evaluate the capability of ultrafast single-shot fast spin-echo MR imaging to assess normal fetal anatomy and abnormalities of different fetal organ systems. Fetal MR imaging was performed prospectively in consecutive 40 pregnant women because of abnormal findings or suspected fetal abnormalities on prenatal US. No statistically significant difference between US and MR imaging was found for the detection of abnormality in any organ system. MR imaging was slightly superior to US with regard to cerebral abnormalities only. In four (10%) of 40 fetuses, additional information provided by MR imaging altered counseling. However, MR imaging of the extremities-face and soft tissues was limited because of the lack of real-time information.     

MR imaging of cerebral hemiatrophy

Computed tomography has been the procedure of choice in evaluation of cerebral hemiatrophy, particularly in those instances where plain radiographic studies of the skull are nondiagnostic. Our experience suggests that magnetic resonance (MR) can easily accomplish the same task. Furthermore, by virtue of its exquisite soft tissue detail, MR can afford additional clarity and information with respect to relative gray-white matter loss, subarachnoid space size, gyral deformity, as well as highlighting asymmetry of the cerebral peduncles, internal capsules and the thalami.     

Generalized multiple-layer appearance of the cerebral cortex with 3D FLAIR 7.0-T MR imaging

To examine the multiple-layer appearance of the cerebral cortex with fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging at 7.0 T, whole-brain volumetric three-dimensional (3D) magnetization prepared FLAIR images were acquired in 12 volunteers (0.8 3 0.8 3 0.8-mm spatial resolution). Signal intensity profiles were evaluated for the anterior frontal (Brodmann area [BA] 10), posterior frontal (BA 6), parietal (BA 7), precentral (BA 4), postcentral (BA 3), occipital (BA 18), and calcarine (BA 17) regions. Variance of the normalized profile was used as the metric for the multiple-layer appearance. Wilcoxon signed-rank tests were performed to compare variances of the profiles between all areas. All cortical areas showed multiple-layered appearances, with a prominent hyperintense band at the external surface of the cortex, a hypointense band deeper in the cortex, and a hyperintense third band. The ranking from least- to most-pronounced layer appearance was as follows: postcentral (variance, 0.04), posterior frontal (variance, 0.05), calcarine (variance, 0.05), precentral (variance, 0.06), parietal (variance, 0.08), anterior frontal (variance, 0.10), and occipital (variance, 0.11). Each region was significantly different from at least one other region. In conclusion, a multiple-layer appearance of the cerebral cortex was found for all cortical regions with high-spatial-resolution 3D FLAIR MR imaging at 7.0 T.     

Human fetal anatomy: MR imaging

Twenty-four pregnant women carrying 26 fetuses (two sets of twins) were imaged with magnetic resonance (MR) imaging at 0.35 T following sonographic evaluation. Each study was retrospectively evaluated to determine which of 33 normal fetal structures were visible on the images and which imaging parameters were most useful for depicting fetal anatomy. Fetal motion degraded fetal images in all but two cases, both with oligohydramnios and in the third trimester of gestation. Nevertheless, many fetal structures were identifiable, particularly in the third trimester. Visualization of fetal anatomy improved with intravenous maternal sedation in five cases. Relatively T1-weighted images occasionally offered the advantage of less image degradation owing to fetal motion and improved contrast between different fetal structures. More T2 weighting was believed to be advantageous in one case for outlining the fetal head and in one case for delineation of the brain. In many cases, structures were similarly identifiable (though with different signal intensities) regardless of the parameters selected. The authors conclude that MR imaging of many fetal structures is currently unsatisfactory and is probably of limited value, particularly in the first and second trimesters. However, the relative frequency and detail with which the fetal head and liver can be depicted indicate that these may be areas for further investigation, and the potential utility of imaging fetal fat warrants further investigation.