Identifying the optimal regional predictor of right ventricular global function: a high-resolution three-dimensional cardiac magnetic resonance study

Right ventricular (RV) function has prognostic value in acute, chronic and peri-operative disease, although the complex RV contractile pattern makes rapid assessment difficult. Several two-dimensional (2D) regional measures estimate RV function, however the optimal measure is not known. High-resolution three-dimensional (3D) cardiac magnetic resonance cine imaging was acquired in 300 healthy volunteers and a computational model of RV motion created. Points where regional function was significantly associated with global function were identified and a 2D, optimised single-point marker (SPM-O) of global function developed. This marker was prospectively compared with tricuspid annular plane systolic excursion (TAPSE), septum-freewall displacement (SFD) and their fractional change (TAPSE-F, SFD-F) in a test cohort of 300 patients in the prediction of RV ejection fraction. RV ejection fraction was significantly associated with systolic function in a contiguous 7.3 cm² patch of the basal RV freewall combining transverse (38%), longitudinal (35%) and circumferential (27%) contraction and coinciding with the four-chamber view. In the test cohort, all single-point surrogates correlated with RV ejection fraction (p < 0.010), but correlation (R) was higher for SPM-O (R = 0.44, p < 0.001) than TAPSE (R = 0.24, p < 0.001) and SFD (R = 0.22, p < 0.001), and non-significantly higher than TAPSE-F (R = 0.40, p < 0.001) and SFD-F (R = 0.43, p < 0.001). SPM-O explained more of the observed variance in RV ejection fraction (19%) and predicted it more accurately than any other 2D marker (median error 2.8 ml vs 3.6 ml, p < 0.001). We conclude that systolic motion of the basal RV freewall predicts global function more accurately than other 2D estimators. However, no markers summarise 3D contractile patterns, limiting their predictive accuracy.     

Left ventricular remodeling after pulmonary autograft aortic valve replacement: evaluation with color-Doppler echocardiography and magnetic resonance imaging

The superior hemodynamic performance of the pulmonary autograft in aortic position is expected to reflect complete regression of hypertrophy and improved ventricular function. We evaluated and compared early and midterm transthoracic color-Doppler echocardiography (TTE) and magnetic resonance imaging (MRI) assessment concerning left ventricular (LV) function, LV mass regression, and performance of the semilunar valves. A total of 42 consecutive patients, mean age 36 +/- 6 years (range 15 to 56 years), were studied. TTE and MRI were performed preoperatively, at discharge, and at 6 and 12 months postoperatively. Left ventricular diameters and function and LV wall thickness and mass were assessed. There was no early and one late postoperative death. Maximum and mean LV outflow gradients were significantly reduced (p = 0.0001 and p = 0.0001, respectively). There was a significant reduction in left ventricular mass to near normal for all patients (p = 0.001) seen after 6 months. This was paralleled by significant reductions in the interventricular septum and posterior wall thickness, but difference was slight during further follow-up. There was a strong correlation between the results obtained by TTE and MRI for LV mass and ejection fraction (r = 0.86 and 0. 87, respectively). The pulmonary autograft operation gives excellent results that are translated into greater, rapid, and near complete regression of LV hypertrophy. Magnetic resonance imaging is a sensitive and noninvasive methodology that provides reliable visualization and quantification of ventricular performance.     

B超、磁共振胆胰管成像、内镜逆行胰胆管造影术在诊断胆总管结石中的价值

目的 探讨B超、磁共振胆胰管成像(MRCP)、内镜逆行胰胆管造影术(ERCP)在胆总管结石诊断中的价值.方法 收集2005年8月至2007年10月怀疑为胆总管结石且同时行B超、MRCP、ERCP的患者384例,对3种检查方法 进行比较分析.结果 384例患者中,最后经ERCP确诊胆总管结石者370例;B超诊断胆总管结石者268例,其中8例为假阳性,诊断准确率为70.3%(260/370);MRCP诊断362例,其中6例为假阳性,诊断准确率96.2%(356/370).有7例患者MRCP发现有胆总管结石和胆总管扩张,ERCP造影仅发现胆总管扩张,但在用取石网篮和取石气囊清理胆道时取出小结石.结论 B超对于胆总管结石的诊断具有一定的准确率,可作为最基本的检查手段,MRCP和ERCP对于胆总管结石的诊断具有较高的一致性,MRCP可部分替代诊断性ERCP,联合应用MRCP和ERCP可提高胆管结石诊断准确率.     

Robot-assisted navigated endoscopic ventriculostomy: implementation of a new technology and first clinical results

Summary Background. Important landmarks in the evolution of advanced neurosurgical techniques during the past decades include microneurosurgery, neuro-endoscopy and its minimally invasive nature, as well as neuronavigation and advanced intra-operative imaging. With conventional neuroendoscopic techniques, e.g. free-hand endoscopy or the use of mechanical or pneumatic holding devices, a definitive and controlled movement of the endoscope within the brain does depend on the experience and manual skill of the individual neurosurgeon. Therefore, the development of robotic systems to assist surgeons in performing complex neurosurgical procedures is a growing field of interest. Method. With the precision robot Evolution 1 (U.R.S. Universal Robot Systems, Schwerin, Germany) a new neurosurgical tool has just become available for the precise steering of instruments within the cranium. After preclinical anatomical as well as precision studies the system was used for robot-assisted navigated endoscopic third ventriculostomies in six patients with hydrocephalus related to aqueductal stenosis. Findings. All robot-assisted navigated endoscopic procedures were successfully completed. The time for the registration procedure and setup of the robot decreased from 60min. for the first procedure down to 30min. The time for the surgical part of the neuro-endoscopic procedure itself ranged from 17 to 35min. During all procedures no system-related complications occured. Interpretation. The use of robotic technology for neuro-endoscopic third ventriculostomies is a major step towards the controlled movement of the neuro-endoscope within the cranium. The start up procedure and calibration of the robot is still time consuming, but the real operation time is comparable to free hand neuro-endoscopy. The steering of the endoscope is facilitated and the precision of the endoscopic movements is noteworthy.     

颈椎间盘突出症的MRI表现及意义

探讨了１１８例颈椎间盘突出症的ＭＲＩ表现及异临床意义。在ＭＲＩ上，本病可分为中央型和侧方型。前者颈椎间盘从其后方中央部位突出，压迫颈髓前方，受压颈椎弯曲、变扁及向后移位；后者可见椎间盘从后外侧呈块状或碎片状突出，压迫颈髓前外侧，神经根向后外侧移位或消失。本组结果表明，ＭＲＩ可直接显示颈椎间盘突出症的部位、类型及颈髓和神经根的受损程度，为颈椎盘间突出症的诊断、鉴别诊断、治疗方法选择和预后判断提供可靠的方法。     

Side-effects after inhalational anaesthesia for paediatric cerebral magnetic resonance imaging

BACKGROUND: The aim of this study was to evaluate the type, incidence and duration of postprocedure side-effects in 168 children within the first 72 h after inhalational anaesthesia for magnetic resonance imaging (MRI). METHODS: Premedication and induction followed standardized routines. Maintenance of anaesthesia was performed with inhalational anaesthetics solely: isoflurane (n=60 of 112; 53%), sevoflurane (n=32 of 112; 29%), desflurane (n=12 of 112; 11%) or halothane (n= 8 of 112; 7%) using a strapped on face mask (FiO2=0.4; flow 5 l.min-1). When indicated, gadolinium was administered (n=45; OF 112; 40%). RESULTS: One hundred and twelve of 168 parents (67%) responded to questionnaires. In these 112 children, pathological MR findings were found supratentorially (n=31; 28%), infratentorially (n=9; 8%), extracerebrally (n=12; 11%) or combined (n=9; 8%). In 56 of these 112 children (50%), 14 different side-effects were reported. One hour after anaesthesia, 55 children suffered between one and four side-effects. Neurological side-effects were associated with age > or = 5 years (P < 0.01) or infratentorial pathophysiology (P < 0.01) and abdominal side-effects (P < 0.02), especially nausea (P < 0.001) with age > or = 5 years. CONCLUSIONS: Our findings indicate the need to inform parents of the incidence and variability of side-effects after inhalational anaesthesia for minimally invasive, diagnostic procedures, such as MRI.     

Analysis of the anatomic changes in the thoracic cage after a lung resection using magnetic resonance imaging

The thoracic cage after a lung resection is filled by the remaining lobes, the elevated diaphragm, the diminished thoracic cage, and by mediastinal shifting. The changes in the thorax after a lung resection were quantified using magnetic resonance imaging. The study group consisted of 39 patients who had undergone a lobectomy, four who had undergone a pneumonectomy, and 14 controls. The left ventricular angle, ascending aortic angle, mediastinal shift, longitudinal length of the thoracic cage, the distance between the thoracic apex and the level of the aortic valve, and diaphragmatic elevation were all measured. After a right lower lobectomy, the mediastinum shifted more rightward than after a right upper lobectomy. The diaphragm became more greatly elevated after a right upper lobectomy than after a right lower lobectomy. When a chest wall resection was added to a right upper lobectomy, the mediastinal anatomical changes decreased. After a left upper lobectomy, the degree of mediastinal shifting was greater than after a left lower lobectomy. A left upper lobectomy shifted the mediastinum at the level of the right atrium. This method is easily reproducible and was found to be effective for quantifying the changes in the thorax after a lung resection. Received: January 12, 2000 / Accepted: May 30, 2000     

Complex hepatic surgery aided by a 1.5-tesla moveable magnetic resonance imaging system

BACKGROUND: Resection represents the best treatment for potentially curable liver tumors; radiofrequency ablation (RFA) is an alternative. The curative potential of RFA may be hampered because the extent of burn is difficult to estimate by ultrasound. We postulated that intraoperative MRI (iMRI) would enable a more accurate assessment of ablation completeness. METHODS: We performed open hepatic surgery in an operating room equipped with a unique, retractable 1.5-T magnet. Patients were selected because it was anticipated that RFA (with or instead of resection) was likelihood and that iMRI might be helpful in making intraoperative decisions. After baseline MRI, lesions were further assessed by ultrasound at the time of open surgery. Lesions were resected and/or ablated, and further imaging confirmed the margins of the procedure. RESULTS: Nine patients underwent the procedure: 1 with metastatic carcinoid, 4 with hepatocellular carcinoma, and 4 with colorectal liver metastases. In 4 patients, iMRI had an effect on decision-making. In 5 individuals, there were nonlocal recurrences, and 1 patient who was never disease-free had a local recurrence. COMMENTS: Intraoperative MRI could potentially impact operative decision-making when ablating extensive disease. Its ability to prevent local recurrences must be determined. Moreover, the role of this technology in the overall treatment armamentarium must be defined.     

核素淋巴造影和动态磁共振淋巴造影诊断肢体淋巴水肿的比较研究

目的 比较核素淋巴造影与磁共振淋巴造影对肢体淋巴水肿的诊断作用.方法 18例肢体淋巴水肿患者分别接受了99Tc-标记的右旋糖酐为造影剂的核素淋巴造影和钆贝葡胺为显影剂的核磁共振淋巴造影检查,从淋巴系统的形态和功能显像结果对2种方法进行了比较.结果 18例中磁共振淋巴造影清晰显示14例患肢的淋巴管,核素淋巴造影只显示1例.磁共振淋巴造影显示16例患肢的腹股沟淋巴结,核索淋巴造影只显示9例.磁共振淋巴造影通过对造影剂的实时追踪能够提供详尽的淋巴系统病变信息.结论 动态磁共振淋巴造影能够更精确和敏感地检测淋巴水肿肢体的淋巴管、淋巴结结构和功能的病变.

Abstract：

Objective To compare the role of radionuclide lymphoscintigraphy and dynamic magnetic resonance lymphangiography ( MRL) for the diagnosis of extremity lymphedema. Methods Sixteen patients with primary extremity lymphedema and two with Klippel-Trenaunay syndrome combined with lymphedema were examined by lymphoscintigraphy using the tracer 99Tc-labelled dextran, and also by MRL using gadobenate dimeglumine as contrast agent. The results of morphological abnormalities and functional state of the lymphatic system at affected limbs from the two imaging methods were compared. Results Lymphatic vessels were imaged in 14 of 18 limbs with lymphedema using MRL, compared with one of 18 using lymphscintigraphy. MRL detected the inguinal nodes in 16 of 17 patients, whereas lymphscintigraphy revealed inguinal nodes in only nine cases. MRL revealed more precise information about structural and functional abnormalities of lymph vessels and nodes than lymphoscintigraphy by real-time measurement of lymph flow in vessels and nodes. Conclusions Dynamic MRL is more sensitive and accurate than lymphoscintigraphy in the detection of anatomical and functional abnormalities in the lymphatic system in patients with extremity lymphedema.     

Computed tomography and magnetic resonance imaging of cerebral coenurosis

A case of Coenurus cerebralis involving both cerebral hemispheres and the interpeduncular cistern is presented to illustrate the computed tomography (CT) and magnetic resonance imaging (MRI) features. In CT scans viable cysts appear as lucent lesions surrounded by a contrast-enhanced peripheral rim. By using multiple echo sequences the cyst content is characterized in magnetic resonance images by a cerebrospinal fluid-like intensity pattern.     

Surgical ventricular restoration based on evaluation of myocardial viability with delayed-enhanced magnetic resonance imaging

OBJECTIVE: We examined whether the determination of myocardial viability by preoperative delayed-enhanced magnetic resonance imaging (DE-MRI) would be useful for planning surgical ventricular restoration (SVR). METHODS: Eight consecutive patients with poor cardiac function (ejection fraction < 30%) due to ischemic cardiomyopathy underwent surgical treatment based on findings of preoperative cine-MRI and DE-MRI. Our surgical strategy consisted of (1) complete revascularization on viable segments; (2) SVR in a patient with extensive nonviable segments; and (3) mitral valve plasty in a patient with a more than moderate degree of mitral regurgitation. Based on the MRI assessments, four of the patients (group A) underwent isolated coronary bypass surgery, and the other four (group B) underwent SVR and mitral valve plasty concomitantly with coronary bypass surgery. Perioperative changes in ventricular function were quantitatively assessed in each group. RESULTS: The mean end-diastolic volume index was reduced from 115 +/- 29 ml/m2 to 95 +/- 14ml/m2 in group A and from 163 +/- 35ml/m2 to 125 +/- 28ml/m2 in group B. The mean end-systolic volume index was reduced from 91 +/- 25ml/m2 to 68 +/- 16ml/m2 in group A and from 135 +/- 36ml/m2 to 98 +/- 28 ml/m2 in group B. The mean ejection fraction increased from 20% +/- 6% to 28% +/- 9% in group A and from 17% +/- 6% to 22% +/- 5% in group B. The mean New York Heart Association (NYHA) functional class was reduced from 3.0 +/- 0.8 to 1.8 +/- 0.6 in group A and from 3.5 +/- 0.5 to 2.2 +/- 0.2 in group B. CONCLUSION: DE-MRI was highly effective in helping to select which patients and which areas of the left ventricle are indicated for SVR, which contributed to excellent early clinical outcomes.     

磁共振扩散加权成像在胰腺癌诊断中的应用

目的 探讨磁共振扩散加权成像(DWl)及相应的表观扩散系数(ADC)在胰腺癌诊断中的应用价值.方法 回顾性分析2009年3月至2011年6月无锡市第二人民医院收治的36例胰腺癌患者和30例健康志愿者的临床资料.66例受试者接受MRI检查,进行DWI扫描.胰腺癌患者的肿瘤组织和癌周组织在T1WI、T2WI及DWI图像中的信号强度比(SIR)的比较采用单因素方差分析;肿瘤组织与癌周组织的ADC值比较采用配对t检验;肿瘤组织、癌周组织分别与健康志愿者胰腺组织的ADC值比较采用独立样本t检验.结果 胰腺癌患者术前MRI检查诊断的准确性达到92％.T2WT、T1WI及DWI图像中,胰腺癌患者的SIR分别为0.203±0.190、0.399±0.201及0.579±0.291,肿瘤组织和癌周组织的信号强度在3组图像间比较,差异有统计学意义(F=5.92,6.15,6.83,P＜0.05);患者在T1WI和DWI图像中的SIR均明显高于T2WI图像(P＜0.05),而T1WI与DWI图像SIR比较,差异无统计学意义(P＞0.05).测量患者肿瘤组织、癌周组织、健康志愿者胰腺组织的平均ADC值分别为(1.40 ±0.24)×10-3 mm2/s、(1.71±0.10) ×10-3 mm2/s、(1.73 ±0.30) ×10-3mm2/s,肿瘤组织与癌周组织、肿瘤组织与胰腺组织的ADC值比较,差异有统计学意义(t=10.54,12.08,P＜0.05).结论 DWI图像可以清晰地显示胰腺癌病灶,ADC值的测定有助于胰腺癌的诊断.     

磁共振血管造影和胰胆管造影在胰头癌外科中的价值

目的探讨磁共振成像（MRI）联合磁共振血管造影（MRA）和胰胆管造影（MRCP）对胰头癌诊断的价值。方法对42例胰头癌患者进行MRI、MRA和MRCP检查,并与术中探查结果及手术方式行对比分析。结果42例胰头癌患者中MRCP和MRA显示癌肿未侵犯邻近组织、血管者24例,癌肿压迫邻近门静脉、肠系膜上静脉者5例,侵犯或浸润邻近血管者10例,远处器官转移者3例。与术中探查结果相符者35例,准确率达89．7％（35／39）。行胰十二指肠切除术者28例,行内引流术者11例,3例行介入治疗,手术切除率为66．7％（28／42）。结论MRCP和MRA对胰头癌患者术前肿瘤转移和周围组织浸润,尤其是对肿瘤血管浸润可明确显示,其影像学结果对病变程度的估计及指导临床治疗决策有重要价值。     

Three-dimensional magnetic resonance imaging of Kommerell diverticulum in a child with recurrent dysphagia

We report a case of a 3-year-old girl with a history of recurrent dysphagia and feeding difficulties. After chest x-ray and esophagogram examination, magnetic resonance imaging revealed the presence of a right-sided aortic arch with an aberrant retroesophageal left subclavian artery arising from a Kommerell diverticulum.     

A comparison of magnetic resonance imaging with electrodiagnostic findings in the evaluation of clinical radiculopathy: a cross-sectional study

Purpose

The aim of this study was to evaluate the agreement of magnetic resonance imaging and electrodiagnostic studies by comparing their findings in patients with clinically suspected radiculopathy. The agreements between these two procedures and clinical findings were also examined.

Methods

In a 2-year cross-sectional study, a total of 114 patients with clinically suspected cervical or lumbosacral radiculopathy were included.

Results

The total agreements between clinical with MRI and EDX findings were 72 and 52 %, respectively while their agreements were similar in group definite (89 vs. 82 %). The agreement between EDX and MRI was 59.6 in total and 49 % with respect to clinical findings.

Conclusion

This study further supports that these two methods are complementary in general. It is reasonable to add EDX when there is discrepancy between MRI and clinical findings or when MRI neurologic findings are not visible.     

Out of hours magnetic resonance imaging for suspected cauda equina syndrome: lessons from a comparative study across two centres

BackgroundCauda equina syndrome, a rare but disabling spinal surgical emergency, requires prompt investigation, ideally using magnetic resonance imaging as patients may require decompressive surgery. Out of hours access to magnetic resonance imaging is only routinely available in major trauma centres and neurosurgical units. Patients in regional hospitals with suspected cauda equina syndrome may require transfer for diagnostic imaging. We retrospectively studied the proportion of patients referred with suspected cauda equina syndrome who required out of hours transfer for magnetic resonance imaging and decompressive surgery.Materials ands methodsRetrospective cohort study of patients referred using online referral platforms with suspected acute cauda equina syndrome and transferred out of hours between 6pm to 8am on weekdays and all day on weekends to two of the largest neurosurgical units in the UK in Birmingham and Cambridge.ResultsA total of 441 patients were referred across both sites with a suspicion of acute cauda equina syndrome; 339 patients were transferred for diagnostic scans and only 16 of them (4.7%) were positive for cauda equina compression, necessitating prompt decompressive surgery. Of the patients with negative magnetic resonance scans, 50% had their discharge or transfer back to referring hospitals delayed by more than 24 hours.ConclusionsOver 95% of patients who were transferred for imaging did not undergo emergency decompression. The authors propose a greater role for the provision of out of hours magnetic resonance imaging in all hospitals admitting emergency patients to streamline management.     

Cerebral vasculitis in Henoch-Schönlein purpura: a case report with sequential magnetic resonance imaging

Neurological complications are rare during the course of Henoch-Schönlein purpura (HSP). We report a 5-year-old girl with HSP who presented with seizures. Sequential magnetic resonance imaging and electroencephalography showed bilateral multifocal cerebral lesions initially, which gradually and completely resolved with clinical improvement. These lesions were compatible with the radiological pattern of the non-hemorrhagic vasculitic involvement of cerebral parenchyma.     

Congenital contracture of the quadriceps muscle: a case report with magnetic resonance imaging

Introduction Case report of a rare form of congenital contracture of the quadriceps muscle. Congenital contracture of the quadriceps muscle is encountered very rarely in daily orthopaedic practice. A few cases have been reported, but unfortunately these did not detail the MRI findings of congenital contracture.Materials and methods A 34-year-old woman presented with difficulty in sitting with full flexion of the bilateral knee joints. She had no history of intramuscular injection, and her brother had a similar abnormality. A physical and radiographical review of the case was conducted.Results A palpable corded induration was detected in the quadriceps muscle which prevented further flexion of the bilateral knee joints. Magnetic resonance imaging of both thighs demonstrated marked atrophy of the rectus femoris muscle and dark signal intensity of the muscle on both T1-weighted and T2-weighted images. It was suggested that the muscles had been replaced by fibrosis.Conclusion This appears to be the first report to include MRI findings of congenital contracture. Clinical awareness of congenital contracture with unique clinical symptoms and radiographic findings may aid the correct diagnosis.     

失神经靶肌肉的弥散张量成像与病理对比研究

目的探讨磁共振弥散张量成像（DTI）在评价兔失神经靶肌肉退变及再生的价值。方法将36只新西兰大白兔右后肢制作失神经支配骨骼肌退变及再生模型,分别于术前、术后1d、3d、1周、2周、3周、4周、6周、8周各时间点对靶肌肉进行DTI及病理检查,每时间点4只,观察失神经侧与对侧正常组腓肠肌及比目鱼肌的FA、ADC值,λ∥,λ⊥值及病理学变化特点。结果 36只兔全部造模成功,术后第1天,失神经侧靶肌肉λ∥值、λ⊥值及FA值均开始下降,以λ∥值最显著,与术前比较有统计学差异（P〈0.05）,病理上靶肌肉肌纤维间质出现水肿;3d～4周,λ∥值、λ⊥值及FA值均逐渐下降,2周时FA值下降至最低值,而λ∥值、λ⊥值分别在4周时下降至最低值,而病理上有血管扩张、充血淤血、渗出、肌纤维灶性萎缩、肌肉间隙增宽的出现;6～8周,三者均逐渐升高、缓慢恢复,相对应病理改变逐渐减轻。经LSD法进行组间对比：λ∥值、λ⊥值及FA值与正常组有统计学差异的分别为1d～6周,1～6周及1～6周（P〈0.05）,而ADC在各组观察期与损伤前均无明显变化。结论失神经靶肌肉的弥散参数λ∥值、λ⊥值及FA值与其病理变化的趋势相一致,DTI能早期、敏感、准确评价失神经靶肌肉退变及再生的情况。