Magnetic resonance in trigeminal neuralgia]

One of the possible causes of the so-called "essential" trigeminal neuralgia is a neurovascular compression of the fifth cranial nerve root at the pons. The demonstration of this hypothesis could orientate the surgical treatment to microvascular decompression. In order to evaluate the role of MRI in the diagnosis of trigeminal neuralgia due to neurovascular compression, the authors present the results of a prospective evaluation of the cranial MR studies of 18 neuralgic patients in comparison with a retrospective evaluation of the cranial MR studies of 50 healthy control subjects. The results show that neurovascular compression can be demonstrated in 83.3% of the neurological patients. In all cases a good correlation between the clinical symptoms, the side of positive MR findings and the surgical findings, when available, was demonstrated. On the other hand, neurovascular compression was demonstrated in 28% of the healthy control subjects. The authors conclude that neurovascular compression can be demonstrated in a high percentage of patients with the so-called "essential" trigeminal neuralgia. Compared with the other imaging modalities (angiography, Computed Tomography) MRI is the best technique in the diagnosis of this disease. In fact, MRI is not only able to differentiate the symptomatic from the essential type of neuralgia, but is also very sensitive in the identification of trigeminal neuralgia due to neurovascular compression. This diagnosis could direct the surgical treatment to microvascular decompression.     

磁共振断层血管成像对原发性三叉神经痛的诊断价值

目的：探讨磁共振断层血管成像(MRTA)对原发性三叉神经痛(ITN)患者神经血管关系的诊断价值及可靠性。方法回顾性分析280例 ITN 患者的临床及 MR 资料,并与手术结果进行盲法对照。结果280例 ITN 患侧神经血管接触、可疑接触或压迫共267例(阳性率95.3%),健侧有66例(假阳性率23.6%);120例手术者,术中发现神经血管接触或压迫118例。患侧与健侧神经血管接触或压迫比较差异有统计学意义(P <0.05)。以手术结果为金标准,MRTA 诊断神经血管接触或压迫的特异度、灵敏度、诊断符合率分别为100%,96.6%,96.7%。结论MRTA 能可靠地显示 ITN 神经血管的关系,其诊断灵敏度和准确率高,对ITN 病因诊断和手术治疗提供客观的依据。     

Magnetic resonance tomographic angiography: diagnostic value in trigeminal neuralgia

A combination of MRI, MR angiography and MR tomographic angiography (MRTA) was used to study the relationship to the root exit zone of the trigeminal nerve to surrounding vascular structures in seven patients with trigeminal neuralgia (TN) and ten patients with no evidence at a lesion in this region. MRTA is the technique for showing the relationship between vessels, cranial nerves and brain stem. MRTA clearly demonstrated the presence of a vessel at the root exit zone of the trigeminal nerve in all patients with TN. In the ten other patients, examination of 20 trigeminal nerves revealed that only one nerve (5%) was in contact with a vessel at the root exit zone. This study supports vascular compression of trigeminal nerves as a cause of TN, and demonstrates the value of MRTA as noninvasive technique for demonstrating compression.     

Angiographic observations in idiopathic trigeminal neuralgia

Twenty-four patients with idiopathic trigeminal neuralgia were treated by neurovascular decompression surgery. All patients underwent preoperative vertebral angiography. After surgery, the vertebral angiograms of these patients were retrospectively reviewed. In 23 of the 24 patients, the superior cerebellar artery (SCA) and/or the anterior inferior cerebellar artery (AICA) compressed the trigeminal nerve. In the remaining case, no such compression by vessels was observed. On review of the angiograms, most of the compressing arteries, and the sites and numbers of compression points could be identified. Most of the caudal points of the SCAs which did not compress the trigeminal nerve were located higher than the compression points of the SCAs. It was therefore concluded that vertebral angiography is useful in the preoperative evaluation of compressing arteries. Since superimposition of arteries could be avoided, the straight AP projection was the most valuable of the three projections employed.     

原发性三叉神经痛的多模态MRI研究进展

原发性三叉神经痛(TN)是最常见的颅神经疾病之一,以三叉神经感觉支分布区反复发作的触电样剧烈疼痛为临床特征,病因不明。多模态MRI技术能够全面评估三叉神经脑池段与邻近血管的毗邻关系、三叉神经形态学改变、三叉神经纤维束的完整性以及相关脑区的结构与功能改变,可以为深入理解TN的发病机制、指导治疗方案的制定以及预后评估提供大量有价值信息。现就多模态MRI技术在TN研究中的技术进展和发展现状予以综述。     

Magnetic resonance imaging features of subacute idiopathic brachial neuritis

A 60-year-old man presented with sudden onset of left shoulder pain followed 2 weeks later by the development of left shoulder girdle weakness. A clinical and electrophysiological diagnosis of subacute idiopathic brachial neuritis was made. The MRI features of subacute muscular denervation in this patient are discussed and the relevant literature reviewed.     

磁共振3D-FIESTA在原发性三叉神经痛诊断中的应用

目的 研究MR三维稳态进动快速成像(3D-FIESTA)序列对原发性三叉神经痛的诊断价值.方法 对23例三叉神经痛患者行3D-FIESTA序列成像并多平面重建,分析患侧组与健侧组三叉神经与邻近血管关系.结果 患侧组与健侧组神经血管接触阳性比例分别为20/23与11/23,神经受压推移比例分别为6/23与0/23,经统计学分析,2组间的差异均有统计学意义(P<0.05).结论 MR 3D-FIESTA序列可以清晰显示三叉神经与邻近血管的关系,对原发性三叉神经痛的诊断具有重要价值.     

高危原发性三叉神经痛的介入治疗

目的 评价经皮穿刺微球囊压迫三叉神经节(PMC)治疗高危原发性三叉神经痛方法的临床效果.方法 回顾性分析从2001年1月至2007年12月采用Mullan方法治疗3053例原发性三叉神经痛患者中804例高危患者采用PMC技术治疗的临床资料.结果 对804例患者行833次手术.术后即刻成功率为97.3%.平均随访36个月,疼痛复发率为6.8%.感觉异常的发生率为3.8%,无角膜溃疡,咀嚼肌无力约占2/3,复视占0.2%.结论 PMC方法是高危原发性三叉神经痛的首选且十分有效的治疗方法之一,尤其对于疼痛累及第一支且高危的患者更有优势.     

Magnetic resonance imaging of shoulders with idiopathic adhesive capsulitis: reliability of measures

The magnetic resonance imaging (MRI) findings in idiopathic adhesive capsulitis (AC) were compared with those of contralateral healthy shoulders and the reliability of measures assessed. Twenty-six consecutive patients (26 AC and 14 healthy shoulders) were prospectively assessed. The main measurements were thickness of the joint capsule and synovial membrane in the axillary recess and rotator interval in T1-weighted spin-echo sequence enhanced with intravenous (IV) gadolinium chelate (Gd-chelate). Reliability was studied by use of the intraclass correlation coefficient (ICC). The mean thickness of the axillary recess on the coronal plane was 9.0±2.2 mm in AC shoulders and 0.4±0.7 mm in healthy shoulders. The mean thickness of the rotator interval on the sagittal plane was 8.4±2.8 in AC shoulders and 0.6±0.8 mm in healthy shoulders. Interobserver reliability was good for the axillary recess, with ICC values of 0.84 for the coronal plane, and good for the rotator interval, with ICC values of 0.80 for the sagittal plane. MRI with IV Gd-chelate injection can show, with acceptable reliability, signal and thickness abnormalities of the shoulder joint capsule and synovial membrane in AC.     

Magnetic resonance imaging of the intratemporal facial nerve in idiopathic peripheral facial palsy

The aim of this study was to investigate the prevalence of facial nerve involvement with gadolinium-enhanced magnetic resonance imaging (Gd-MRI) in patients with idiopathic peripheral facial palsy (IPFP), and to discuss the localization and the pattern of enhancement. A total of 13 patients (9 female, 4 male) with IFPF were included in this study. Topographic tests and electromyography (EMG) were performed, and MRI was taken. Ten subjects whose cranial MRIs were taken for nonorganic pathology served as the control group. Twelve of 13 paralytic facial nerves had enhancement on postcontrast images. Two facial nerves of the control group demonstrated enhancement. We found a correlation between the enhancement of the facial nerve and the time for recovery. The average time from the onset of facial palsy to the recovery in patients with enhancement was 14 weeks, whereas it was 6 weeks in patient with no enhancement. Finally, all patients had complete recovery of the facial nerve function. We concluded that contrast enhancement of the paralytic facial nerve can be a radiological sign of a neural inflammation and may indicate a prolonged recovery.     

Magnetic resonance imaging methodology

Introduction  

Magnetic resonance (MR) methods are non-invasive techniques to provide detailed, multi-parametric information on human anatomy, function and metabolism. Sensitivity, specificity, spatial and temporal resolution may, however, vary depending on hardware (e.g., field strength, gradient strength and speed) and software (optimised measurement protocols and parameters for the various techniques). Furthermore, multi-modality imaging may enhance specificity to better characterise complex disease patterns.     

磁共振pH成像的研究

<正>1概述磁共振成像(MRI)技术的重要优势在于其无放射损伤及组织结构的高分辨力,可无创实时地检测组织结构及代谢物。众所周知,人体正常机能活动有赖于正常的细胞内外环境,包括正常的酸碱度     

磁共振pH成像的研究

1概述 磁共振成像（MRI）技术的重要优势在于其无放射损伤及组织结构的高分辨力,可无创实时地检测组织结构及代谢物。众所周知,人体正常机能活动有赖于正常的细胞内外环境,     

Magnetic resonance imaging in idiopathic retroperitoneal fibrosis: measurement of T1 relaxation time

Magnetic resonance imaging at 0.08 Tesla was performed in nine patients with proven idiopathic retroperitoneal fibrosis. A total of 11 scans was performed. Three patients were scanned before diagnosis; one of these also had two follow-up scans. A further six patients were scanned a variable time after diagnosis and treatment. On each scan, a periaortic soft-tissue mass was readily identified, the distribution corresponding to that seen on computed tomography. There was no difference in the mean T1 relaxation time of the mass between patients scanned before diagnosis and those scanned after treatment. However, the patient followed with serial scans showed a progressive reduction in the T1 value of the mass with time. Comparison with results obtained in patients with lymphoma suggests that the T1 values in retroperitoneal fibrosis are lower than in lymphoma, particularly non-Hodgkin's lymphoma.     

Magnetic resonance imaging of atherosclerosis

Abundant data now link composition of the vascular wall, rather than the degree of luminal narrowing, with the risk for acute ischemic syndromes in the coronary, central nervous system, and peripheral arterial beds. Over the past few years, magnetic resonance angiography has evolved as a well-established method to determine the location and severity of advanced, lumen-encroaching atherosclerotic lesions. In addition, more recent studies have shown that high spatial resolution, multisequence MRI is also a promising tool for noninvasive, serial imaging of the aortic and carotid vessel wall, which potentially can be applied in the clinical setting. Because of the limited spatial resolution of current MRI techniques, characterization of coronary vessel wall atherosclerosis, however, is not yet possible and remains the holy grail of plaque imaging. Recent technical developments in MRI technology such as dedicated surface coils, the introduction of 3.0-T high-field systems and parallel imaging, as well as developments in the field of molecular imaging such as contrast agents targeted to specific plaque constituents, are likely to lead to the necessary improvements in signal to noise ratio, imaging speed, and specificity. These improvements will ultimately lead to more widespread application of this technology in clinical practice. In the present review, the current status and future role of MRI for plaque detection and characterization are summarized.     

Magnetic resonance imaging of pyomyositis

Pyomyositis is a relatively rare entity in temperate climates. Because of its rarity and its nonspecific clinical and radiographic findings, pyomyositis may be misdiagnosed and may cause severe morbidity and mortality. We present magnetic resonance imaging findings in two cases of pyomyositis. Magnetic resonance imaging was helpful in differentiating other pathological processes from pyomyositis, outlining the extent of involvement, and localizing the fluid collection.     

Magnetic resonance imaging of pilomatricoma

Two patients (a 16-month-old boy and a 53-year-old man) were referred for MR imaging of a small, subcutaneous nodule at the forearm. Plain films were available in one patient and showed a non-specific well-circumscribed lesion. Upon ultrasonography (1 patient), a nodular, well-circumscribed, hyperechoic lesion was seen. In both cases spin-echo (SE) T1-weighted images (T1W1) showed homogeneous, intermediate signal intensity (SI). On gadolinium-enhanced T1W1 (1 patient), no enhancement was observed. Both lesions showed predominant low-to-intermediate SI on T2WI. At histological examination characteristic findings of pilomatricoma were observed.     

Magnetic resonance imaging of mesenrhombencephalitis

Mesenrhombencephalitis is a rare inflammatory process involving the midbrain, pons, and medulla. The diagnosis is difficult as clinical and laboratory findings may be nonspecific. Magnetic resonance (MR) imaging demonstrates abnormal T2 signal in the brainstem, which can suggest the diagnosis. The clinical, laboratory and MR imaging findings are described in five patients with this serious, life-threatening disease. MR imaging can be of value in the early diagnosis of this rare disorder.     

Magnetic resonance imaging of hemorrhage

The magnetic resonance imaging (MRI) characteristics of evolving hemorrhage are discussed and compared with those of computed tomography (CT). Studies of 15 hematomas were undertaken in four mongrel dogs. The hematomas were created by the injection of autologous blood into the subcutaneous tissues of the thigh. The hematomas were studied serially with both MRI and CT. Pulse sequences included spin-echo (2100 msec TR, 40 and 80 msec TE) and inversion-recovery (2100 msec TR, 400 msec TI, 40 msec TE). Relaxation times (T1 and T2) were calculated in each case. CT values (H) were also obtained. In addition, 24 single and 14 serial scans of hemorrhage were obtained from 24 patients. MRI was performed on a 0.15-T resistive magnet scanner. T1 and T2 relaxation times and CT values decreased as the hematomas resolved. T1 and T2 relaxation times of intraparenchymal hemorrhage tended to remain elevated with time. MRI seems to be more sensitive than CT for the detection of hemorrhage, primarily because of superior contrast resolution.