Diagnostic performance of combined cardiac MRI for detection of coronary artery disease

Objective

To evaluate the diagnostic performance of stress perfusion cardiac MR (CMR) for detecting significant CAD (≥70% narrowing) in comparison with invasive coronary angiography (ICA) as a reference standard.

Methods

Examinations of 54 patients who underwent both stress perfusion CMR and ICA for investigation of CAD between 2007 and 2009 were evaluated. The CMR protocol included dipyridamole stress and rest perfusion, stress and rest cine MRI for assessment of ventricular function and delayed gadolinium enhancement for assessment of myocardial viability and detection of infarction. CMR interpretation was performed by 2 observers blinded to the results of ICA and the clinical history.

Results

From a total of 54 patients, 37 (68.5%) showed significant CAD in 71 coronary territories. A perfusion defect was detected in 35 patients and in 69 coronary territories. Individual stress perfusion CMR evaluation showed the highest accuracy (83%) of the CMR techniques. The combined analysis using all sequences increased the overall accuracy of CMR to 87%.

Conclusion

Combination of perfusion and cine-MR during stress/rest, associated to delayed enhancement in the same protocol improves CMRI diagnostic accuracy and sensitivity for patients with significant coronary stenosis, and may therefore be helpful for risk stratification and defining treatment strategies.     

磁共振成像对肛瘘分级的价值

目的探讨磁共振成像（MRI）对肛瘘分级价值。方法经手术证实的肛瘘患者26例,全部行MRI检查,检查序列主要包括轴面T1WI、T2WI和轴面、冠状面抑脂T2WI序列。结果 26例肛瘘中,Ⅰ级10例,Ⅱ级6例,Ⅲ级5例,Ⅳ级3例,Ⅴ级2例。MRI诊断26例肛瘘中共有28个瘘管,26个内口,31个外口,14个脓肿,敏感度分别达93%、93%、97%、100%。结论 MRI可以对肛瘘准确分级,对正确的手术治疗非常重要。     

MRI in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) affects ≈1.4 million people in North America and, because of its typical early age of onset and episodic disease course, IBD patients often undergo numerous imaging studies over the course of their lifetimes. Computed tomography (CT) has become the standard imaging modality for assessment of IBD patients because of its widespread availability, rapid image acquisition, and ability to evaluate intraluminal and extraluminal disease. However, repetitive CT imaging has been associated with a significant ionizing radiation risk to patients, making MRI an appealing alternative IBD imaging modality. Pelvic MRI is currently the imaging gold standard for detecting perianal disease, while recent studies indicate that MRI bowel-directed techniques (enteroclysis, enterography, colonography) can accurately evaluate bowel inflammation in IBD. With recent technical innovations leading to faster and higher resolution body MRI, the role of MRI in IBD evaluation is likely to continue to expand. Future applications include surveillance imaging, detection of mural fibrosis, and early assessment of therapy response.     

MRI of dural carotid-cavernous fistulas comparisons with postcontrast CT

Ten patients with dural carotid-cavernous fistulas (CCFs) who presented with ophthalmic manifestations were studied using postcontrast computed tomography (CT), magnetic resonance imaging (MRI), and selective cerebral arteriography. The lesions of two patients were bilateral. An enlarged cavernous sinus (CS) was diagnosed in 6 of the 12 involved sides using postcontrast CT. An abnormal flow void in the CS was detectable in 11 of the 12 using MRI. A dilated superior ophthalmic vein (SOV) was demonstrated in all of the involved sides by postcontrast CT, and in 9 of the 12 by axial MRI. Thus, both postcontrast CT and MRI are relatively useful and complementary in the diagnosis of dural CCFs. Patients should be followed with selective cerebral arteriography for definitive diagnoses and for therapeutic planning.     

PET-CT enteroclysis: a new technique for evaluation of inflammatory diseases of the intestine

Purpose While CT/MR enteroclysis provides excellent anatomical details, it fails to provide information on metabolic activity of the inflammatory lesions of the intestine. We conceptualized a fusion of metabolic imaging techniques such as PET and an anatomical imaging modality such as CT enteroclysis to derive information both on morphological details and functional activity of lesions at the same time. Patients and methods In a prospective study, we included 17 adult patients with newly diagnosed inflammatory diseases of the intestine. Low dose whole body PET-CT scan was obtained first, which began at approximately 60 min after injection of 10 mCi of ¹⁸fluoro-deoxyglucose (FDG). Subsequently, PET-CT enteroclysis of the abdomen was performed after infusion of 2 l of 0.5% methylcellulose through a naso-jejunal catheter. Results Fourteen patients had abnormal and three had normal PET-CT enteroclysis studies. Twenty-three segments of small intestine and 27 segments of large intestine showed increased FDG uptake. The detection rate of PET-CT enteroclysis was significantly higher (total =50 segments, 23 segments of small intestine and 27 segments of large intestine) as compared with barium studies (16 segments of small intestine) and colonoscopy (17 segments of large intestine) combined together (total =33 segments). In addition PET-CT enteroclysis showed extra-luminal FDG uptake (lymph nodes in two, sacroilitis in two, and mesenteric fat proliferation in five). Conclusions As a single investigation, PET-CT enteroclysis detects a significantly higher number of lesions both in the small and large intestine in comparison to that detected by conventional barium and colonoscopy combined together. This technique is non-invasive, feasible and very promising. Financial disclosure: All the authors of this study declare no conflict of interest and financial obligation.     

Multidetector CT enteroclysis versus barium enteroclysis with methylcellulose in patients with suspected small bowel disease

The purpose of this study was to evaluate the diagnostic accuracy of multidetector-CT enteroclysis (MDCT-E) versus barium enteroclysis with methylcellulose (BE) in clinically selected patients with suspected small bowel disease. We prospectively studied 52 patients who underwent unenhanced and contrast-enhanced multidetector CT (16 rows) after administration of 2–2.5 l of methylcellulose by naso-jejunal tube. BE was performed after administration of barium 60% w/v (200–250 ml) and methylcellulose (1–2 l). Patients with radiological signs of Crohn’s disease were classified into the following subtypes: active, fibrostenotic, fistulising/perforating, reparative or regenerative subtypes. Twenty-eight patients also underwent endoscopy. The radiological prevalent subtype was the active subtype. The sensitivity, specificity and diagnostic accuracy of MDCT-E versus BE was 83%, 100% and 89%, respectively. BE showed five false negative CT cases due to early Crohn’s disease; endoscopy confirmed positive cases of the CT and the BE, but showed one false negative case of the BE. Together, MDCT enteroclysis and BE permitted the diagnosis of Crohn’s disease in 30 patients, adhesions in one patient, lymphoma in two patients and carcinoid tumours in two patients. In conclusion, MDCT-E permits good representation of pathological patterns. Early stages of Crohn’s disease are better evaluated by BE.     

Magnetic resonance imaging for evaluation of disease activity in Crohn’s disease: a systematic review

To systematically review the evidence on the accuracy of MRI for grading disease activity in Crohn’s disease (CD). The MEDLINE, EMBASE, CINAHL and Cochrane databases were searched for studies on the accuracy of MRI in grading CD compared to a predefined reference standard. Two independent observers scored all relevant data. Three disease stages were defined: remission, mild and frank disease. The accuracy rates of MRI per disease stage were calculated by means of a random-effects model. Seven studies were included from a search resulting in 253 articles. In total 140 patients (16 patients in remission, 29 with mild disease and 95 with frank disease) were used for data analysis. MRI correctly graded 91% (95% CI: 84–96%) of patients with frank disease, 62% (95% CI: 44–79) of patients with mild disease and 62% (95% CI: 38–84) of patients in remission. MRI more often overstaged than understaged disease activity; MRI overstaged disease activity in 38% of patients in remission, mostly as mild disease. Overstaging of mild disease was observed in 21%, understaging in 17%. MRI correctly grades disease activity in a large proportion of patients with frank disease. For patients in remission or with mild disease, MRI correctly stages disease activity in many patients (62%).     

MRI scoring system including dynamic motility evaluation in assessing the activity of Crohn's disease of the terminal ileum

RATIONALE AND OBJECTIVES: We sought to investigate the value of a MRI scoring system including dynamic motility evaluation in the assessment of small bowel Crohn's disease activity. MATERIALS AND METHODS: From March 2005 to December 2006, 52 patients with suspected Crohn's disease onset or relapse underwent MRI on a 1.5-T magnet. Bowel distention was achieved orally assuming a mean of 1.6 L of a polyethyleneglycol (PEG) preparation. Per-patient assessment of disease activity was based on a scoring system including evaluation of morphology and motility of the small bowel and perivisceral structures (true-FISP, cine-true-FISP, and HASTE T2W sequences) and dynamic assessment of parietal contrast enhancement (FLASH T1W sequence). Patients were included in three categories, using endoscopic biopsy as the standard reference: no activity/quiescent disease, mild activity, or moderate-to-severe activity. Patients without terminal ileum involvement were excluded from data analysis. RESULTS: MRI allowed a detailed and panoramic evaluation of the small bowel in all subjects examined. MRI properly assessed 14 of 16 (87.5%) cases of no activity/quiescent disease, 12 of 14 (85.7%) cases of mild activity, and 15 of 15 (100%) cases of severe activity. Overall, activity score led to a per-patient misdiagnosis of disease activity in a nonsignificant proportion of subjects (4 of 45; 8.8%) (P > .05), determining two false-positive and two false-negative results of mild disease activity. Sensitivity, specificity, PPV, NPV, and overall accuracy in assessing disease activity were 93.1%, 87.5%, 93.1%, 87.5%, and 91.1%, respectively. CONCLUSION: Accurate assessment of Crohn's disease activity is achieved by using an activity score providing an overall interpretation of MRI findings.     

MRI对肠梗阻的诊断价值

目的：探讨MRI在诊断肠梗阻中的应用价值。方法回顾性分析45例MRI诊断为肠梗阻患者的影像表现。将MRI诊断结果与手术、病理结果或临床诊断对照。结果恶性病变14例：肠腔内恶性梗阻11例,腹腔内其他器官恶性肿瘤伴多发腹膜转移粘连者3例。良性病变26例：结肠息肉2例,乙状结肠扭转、巨结肠、肠套叠、闭孔疝、膈疝及腹膜后淋巴组织反应性增生患者各1例,粘连性肠梗阻18例。另外5例为肠郁张。本组病例MRI对梗阻有无的明确率达88．9％,定位准确率达82．5％,定性准确率达75％。结论 MRI在判断肠梗阻的部位、性质、程度方面具有较高的准确性,可为临床制定治疗方案提供重要信息。     

肛瘘的高分辨MRI表现

目的探讨体外相位阵列线圈高分辨MRI对肛瘘检查的准确性及其价值。方法经手术证实的肛瘘患者20例，全部行体外相位阵列线圈高分辨MRI检查，检查序列主要包括高分辨轴面、矢状面和冠状面T2 WI和轴面抑脂T2 WI序列。结果20例肛瘘共27个原发瘘管、24个内口，28个外口，10个肛周脓肿。高分辨MRI对原发瘘管、肛周脓肿、内口显示的敏感度分别为92．6％（25／27）、100．0％（10／10）和91．7％（22／24），特异度分别为92．3％（12／13）、96．3％（26／27）和85．7％（12／14）。结论体外相位阵列线圈高分辨MRI可较准确地判断肛瘘的分型、瘘管走行及有无脓肿形成，对正确的手术治疗非常必要。     

T1 WI SPIR增强MRI在肛瘘中的应用价值

目的通过T1WI频谱预饱和反转恢复序列(SPIR)钆增强MRI与其他常规MRI序列比较,评估增强T1WI SPIR MRI在使用肛肠水囊肛瘘患者中的临床应用价值。资料与方法16例经手术证实的肛瘘患者术前均行MRI检查,序列包括横断位T1WI、T2WI频谱选择性衰减反转恢复序列(SPAIR)和钆增强T1WI SPIR。检查前,均向患者肛管直肠内置入肛肠水囊以撑开肛管和直肠。评估和比较MRI各序列显示的瘘管、内口、瘘管分支及脓腔。结果MRI显示复杂性肛瘘11例,其中高位复杂性肛瘘6例,单纯性5例。对比增强T1WI SPIR MRI发现瘘管(100.0%)、内口(81.3%)、分支(81.3%)和脓腔(100.0%)的准确率较T1WI及T2WI SPAIR MRI为高。Kruskal-Wallis检验显示上述各序列对内口显示的差异有显著统计学意义(χ2=15.9,P=0.003)。对比增强T1WISPIR MRI显示内口最多。结论横断位钆增强T1WI SPIR序列在使用肛肠水囊后能提供患者瘘管更丰富的细节,提高肛瘘诊断的准确率。     

Diagnostic use of isotropic diffusion-weighted MRI in patients with ischaemic stroke: detection of the lesion responsible for the clinical deficit

We examined the diagnostic use of isotropic diffusion-weighted (DW) MRI in 140 consecutive patients suspected of or diagnosed as having an ischaemic stroke. Isotropic DW imaging could demonstrate the lesion responsible for the clinical deficit in patients with multiple cerebral infarts at an early stage, even small lesions without a perifocal oedema or mass effect. Accurate diagnosis by DW images may, however, be difficult about 2 weeks after the onset of stroke. Received: 15 November 1998 Accepted: 12 February 1999     

MRI联合MRCP对肝门部胆管癌的诊断价值

目的探讨MRI与MRCP对肝门胆管癌（HCC）的诊断价值。方法30例手术病理证实的（HCC）患者均经增强前MRI及MRCP，20例还经动态增强MRI。获自上述3种方法的影像表现进行了对比性分析。结果MRCP对肝门部胆管梗阻水平定位准确率达93．3％（28／30），增强前与增强后MRI对病变的定性准确率为83．3％（25，30）。增强前后MRI联合MRCP对病变可切除性的术前评估准确率为80％（24／30）。MRCP显示了所有病例中肝内胆管不同程度扩张，肝门区胆管狭窄、中断或腔内充盈缺损。增强前MRI显示了30例中20例肝门区有稍长T1、稍长T2信号的肿块影。经动态增强MRI20例中17例其肿块表现为延迟期缓慢持续强化，而10例无肿块者表现为管壁增厚、强化，管腔狭窄。结论增强前后MRI可以显示HCC的特征性改变，如联合应用MRCP则有助于提高其定位、定性诊断准确率。     

炎症性肠病的MRI进展

炎症性肠病（IBD）是一组病因不明的慢性炎症性肠病,包括克罗恩病（CD）和溃疡性结肠炎（UC）,常导致肠腔狭窄或穿透性肠损伤,其病程发展过程中需要经常评估疾病的活动性和并发症,以便制定正确的治疗方案。MRI软组织分辨力高,可以获得肠壁的动态信息,已应用于对IBD的检出、评估病变活动性、判断病变纤维化程度及鉴别CD与UC等。就MR小肠成像、扩散加权成像、动态增强MRI及磁化传递成像等在IBD中的应用进展予以综述。     

颅脑MRI在老年急性眩晕患者诊断中的应用价值

目的：探讨颅脑MRI检查在老年急性眩晕患者中的诊断价值。方法：回顾性分析我科眩晕门诊就诊的老年急性眩晕患者共136例,年龄60-85岁,平均年龄72．5岁。所有患者均以眩晕为首发症状,在眩晕发作后的1-7天内行MRI检查。对阳性发现进行统计分析。结果：老年急性眩晕患者共136例,MRI检查异常发现共33例,占24．3％。其中包括腔隙性脑梗死19例,脑干梗死5例,小脑梗死4例,脑萎缩2例,听神经瘤2例,小脑出血1例。在以单纯眩晕为表现的28例患者中,5例（17．9％）患者MR／可发现异常,包括小脑梗死1例,脑干梗死1例,多发腔隙性脑梗死3例。结论：老年急性眩晕患者颅脑MRI约1／4患者可发现异常。MRI能够提高老年眩晕患者中枢性眩晕的识别率,尤其对以单纯眩晕发作为临床表现的患者,有利于早期诊断,避免漏诊、误诊。     

MRI在肠梗阻诊断中的进展

肠梗阻是常见的疾病,占急腹症的20%,有起病急、进展快、病死率高的特点,故早期诊断肠梗阻对愈后至关重要。常规MRI作为一种简便又无创的检查方法,多种成像技术,如MRI水成像(MRH)、MR胆胰管成像(MRCP)、MR肠道成像(MRE)、MR电影成像(Cine MRI)对肠梗阻的定位及病因诊断均较CT准确,而功能MRI的多种成像序列通过各自成像参数的特点能够反映不同的微观病变,对肠梗阻早期诊断有较高的价值。就MRI应用于诊断肠梗阻的技术及其进展予以综述。     

小肠磁共振成像的研究进展

影像学检查是诊断小肠疾病的主要检查方法,近年来随着磁共振技术的迅猛发展,磁共振小肠成像临床应用越来越广泛,本文拟从比较影像学、标本及动物实验研究、临床研究等几个方面对小肠的磁共振成像研究状况进行综述,以期对小肠的磁共振检查技术有一个整体的认识。     

Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease

Objectives

To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease.

Methods

Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon + coecum, transverse colon, descending colon + sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann–Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables.

Results

Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r = 0.485 and r = 0.206) and ME per patient correlated moderately with CDEIS (r = 0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p < 0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r = 0.492), not with CDAI and CRP.

Conclusions

DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.     

复杂性肛瘘的中医证型与临床资料及MRI特征的相关性研究

目的:分析复杂性肛瘘的中医证型与临床资料及MRI特征的相关性,为该病的中医辨证分型提供客观依据.方法:收集58例复杂性肛瘘的临床资料及MRI表现,包括性别、年龄、身高、体质量、体质量指数(BMI)、既往脓肿史等,记录患者中医证候及分型.MRI观察主瘘管的信号强度、内口位置、长度、深度及支管信号强度等影像学参数.结果:5...