Harmonic imaging improves sensitivity at the expense of specificity in the detection of patent foramen ovale

Contrast echocardiography using agitated saline is widely employed to detect right to left shunt in patients with suspected patent foramen ovale (PFO). The sensitivity of fundamental transthoracic echocardiography (FTTE) is often limited by poor far-field resolution. The purpose of this study was to evaluate the test characteristics of harmonic imaging during transthoracic echocardiography (HTTE) for the detection of PFO. METHODS: Sixty-four patients referred for transesophageal echo (TEE) for clinical indications underwent FTTE and HTTE during saline contrast injections. RESULTS: TEE identified nine PFOs. For FTTE, the sensitivity was 78% and the specificity was 100%. For HTTE, the sensitivity was 100% and the specificity was 82%. All ten false positives with HTTE occurred after five cardiac cycles, suggesting transpulmonary transit of the bubbles. CONCLUSION: In the detection of PFO, HTTE improves sensitivity at the expense of specificity, particularly if the timing of contrast appearance in the left heart is ignored.     

Patent foramen ovale: standards for a preclinical model of prevalence, structure, and histopathologic comparability to human hearts.

BACKGROUND: This study evaluated and standardized a Patent Foramen Ovale (PFO) preclinical model in gross anatomic and histopathologic features. METHODS: We examined 150 necropsy-derived domestic porcine hearts, age 4-6 months for PFO prevalence, appearance, and size. Histopathologic preparations were standardized and processed identically to 24 post-mortem human hearts aged 16-62 years. A measurement scheme was developed for PFO atrial openings, tunnel length, and histopathologic features to compare porcine and patient hearts. RESULTS: PFO was found in 32 of the 150 porcine hearts (prevalence 21.3%). Twenty-five porcine PFO underwent standard characterization by tunnel length, and right, and left atrial orifice diameters. Logarithmic regression analysis between porcine PFO tunnel length and left atrial orifice area demonstrated a significant positive relationship (P = 0.0162, R(2) = 0.227). The porcine PFO tunnel length was significantly longer than in humans (12.0 +/- 4.0 mm vs. 7.1 +/- 3.1 mm respectively, P < 0.0001). Histopathologic comparison was made using serial sections perpendicular to the atrial septum and the tunnel long axis. Human and porcine PFO lesions demonstrated strong similarities in tissue cells, connective tissue, and matrix composition. CONCLUSIONS: PFO assessment was standardized in both macroscopically and histopathologically, with quantitative and qualitative comparisons feasible using a porcine preclinical model. PFO prevalence in domestic swine is identical to humans, and microscopic structures very similar to humans. The domestic swine PFO model appears useful to evaluate new interventional closure technologies due to comparability in microscopic features. Tunnel length should be carefully evaluated due to differences across pigs and patients.     

Interatrial defect sizing by intracardiac and transesophageal echocardiography compared with fluoroscopic measurements in patients undergoing percutaneous transcatheter closure.

The purpose of this study was to evaluate prospectively the feasibility and accuracy of using echocardiographic measurements by transesophageal and intracardiac echocardiography (TEE and ICE, respectively) for interatrial septal defect sizing during percutaneous transcatheter closure. Forty-two patients underwent balloon sizing of interatrial septal defects using TEE in 21 of them and ICE in the other half. These measurements were correlated with quantitative fluoroscopic analysis and evaluated for bias and agreement between methods using a Bland-Altman analysis. Echocardiographic measurements were obtained by ICE and TEE in all patients. An excellent correlation was found between TEE and quantitative fluoroscopy (r = 0.898; P < 0.001) and between ICE and quantitative fluoroscopy (r = 0.876; P < 0.001), with a significant agreement (P < 0.001) and minimal positive bias toward the echocardiographic measurements. Both TEE and ICE are excellent methods of interatrial defect sizing when compared with quantitative fluoroscopic measurements.     

Paradoxical Embolism

Paradoxical embolism is an important clinical entity among patients with venous thromboembolism in the presence of intracardiac or pulmonary shunts. The clinical presentation is diverse and potentially life-threatening. Although the serious nature and complications of paradoxical embolism are recognized, the disease entity is still rarely considered and remains under-reported. This paper provides an overview on the different clinical manifestations of paradoxical embolism, describes the diagnostic tools for the detection of intracardiac and pulmonary shunts, reviews therapeutic options, and summarizes guideline recommendations for the secondary prevention of paradoxical embolism.     

Patent foramen ovale, dialysis and microembolization

Background: Haemodialysis (HD) circuits are known to produce microemboli. Patent foramen ovale (PFO) may be important in HD patients by allowing right to left intracardiac shunting of microemboli (blood clots or microbubbles), which may pass into the cerebral circulation. Methods: We undertook bubble contrast transthoracic echocardiography to identify PFO in HD patients and in a control population of peritoneal dialysis patients. We interrogated draining arteriovenous fistulae to confirm that microemboli are created during HD. We then undertook transcranial Doppler scanning of the middle cerebral artery before and during dialysis, with and without Valsalva augmentation, to detect cerebral microemboli in HD patients and in the control group. Results: Eighty patients (age 60.4 ± 15.0 years) were recruited to the study. In 12 of 51 HD patients and five of 29 peritoneal dialysis patients a PFO was found (21.3%). Ultrasound scanning of draining arteriovenous fistulae showed a significant difference in the number of microemboli before (1.63 ± 3.47 hits per 5 min) and during (31.6 ± 28.9 hits per 5 min) HD (P = 0.012). However, there was no evidence of microembolization to the middle cerebral artery before or during HD in the study or control groups. Conclusions: Although microemboli are detectable in the draining arteriovenous fistulae of patients undergoing HD, there was no evidence of cerebral microembolization in the middle cerebral artery during HD in those with or without a PFO. The results contrast with previous reports demonstrating microemboli in the carotid circulation during HD.     

椎动脉起始位置与穿出颈椎横突孔高度关系的三维CT血管成像研究

目的通过三维CT血管成像(CTA)探讨椎动脉起始位置与穿出颈椎横突孔高度的关系。方法回顾性分析2017年3月至2019年3月河北医科大学第二医院神经外科行头颈上胸部CTA检查的480例患者的临床资料。将图像传输至图像后处理工作站进行骨质和血管重建,观察双侧椎动脉的起源、走行及穿出颈椎横突孔的高度。对于右侧椎动脉起源正常者,根据穿出颈椎横突孔的高度分为C₄、C₅、C₆组,每组随机选取10例分别测量右侧椎动脉起始位置至右侧颈总动脉起始的距离(L1)和右侧甲状颈干的距离(L₂),以L₁/(L₁+L₂)×100%计算椎动脉起始的相对位置。结果480例患者中,457例(95.2%)双侧椎动脉起源位置正常,均起源于锁骨下动脉,另23例(4.8%)起源异常,其中左侧椎动脉起源于主动脉弓19例、左侧颈外动脉1例;右侧椎动脉起源于右侧颈总动脉3例,且均合并迷走右锁骨下动脉。480例患者中,405例(84.4%)双侧椎动脉经C₆横突孔穿出;另75例(15.6%)穿出高度异常,其中左侧34例,经C₃、C₄、C₅、C₇横突孔穿出的分别有1、4、24、4例,直接入枕骨大孔1例;右侧41例,经C₃、C₄、C₅横突孔穿出的有1、14、26例。椎动脉起源异常的患者,左侧椎动脉起自主动脉弓的占比最高(19/20),且多数穿出颈椎横突孔的高度异常(18/19);右侧椎动脉均起自右侧颈总动脉合并迷走右锁骨下动脉(3/3),且穿出颈椎横突孔的高度均异常(3/3)。椎动脉起源正常的患者,96.7%(445/460)的左侧椎动脉穿出颈椎横突孔的高度正常,92.0%(439/477)的右侧椎动脉穿颈椎横突孔高度正常。3组右侧椎动脉起源正常的患者椎动脉起始的相对位置的差异有统计学意义[C₄组:(24.3±2.1)%、C₅组:(47.9±6.6)%、C₆组:(77.7±1.7)%,H=20.178,P<0.001]。结论椎动脉起始位置异常时,其穿出颈椎横突孔的高度多异常。右侧椎动脉的起始相对位置越靠近右侧颈总动脉时,穿出颈椎横突孔的高度越高;而越靠近右侧甲状颈干,穿出颈椎横突孔的高度越低。     

成人圆孔锥形束CT测量研究

目的:探讨成人正常圆孔的解剖形态,为临床提供指导。方法:通过锥形束CT(CBCT)对200个正常国人的圆孔解剖形态进行观测。结果:圆孔与蝶窦的关系分为窦旁型、窦内型、部分窦内型3类。矢状面上圆孔的走行分为3类:①斜向前下方走行;②前后向走行,平行于横断面走行;③斜向前上方走行。(斜)横断面或横断面上圆孔的走行分3类:①前外到后内方走行;②由前向后互相平行走行;③前内向后外方向走行。矢状面上圆孔前方开口的直径为(3.35±0.61)mm,后方开口的直径为(3.28±0.60)mm,长度为(6.91±1.51)mm;(斜)横断面上圆孔前方开口的直径为(3.50±0.76)mm,后方开口的直径为(3.25±0.45)mm,长度为(6.83±1.76)mm;腭大孔到圆孔前方开口的距离为(34.91±2.31)mm。结论:CBCT可以精确地观测到圆孔的解剖形态,为临床手术提供指导。     

The Validity of Cone-beam Computed Tomography in Measuring Root Canal Length Using a Gold Standard

Introduction

The distance between a coronal reference point and the major apical foramen is important for working length determination. The aim of this in vitro study was to determine the accuracy of root canal length measurements performed with cone-beam computed tomographic (CBCT) scans using a gold standard.

Methods

A total of 162 teeth (198 root canals) in 16 dry human dentulous mandibles were scanned using a 3DX-Accuitomo CBCT scanner (Morita 3DX; J Morita Mfg Corp, Kyoto, Japan). The root canal length was measured with CBCT data. All teeth were extracted atraumatically and endodontically accessed; the root canal length was measured blindly using a #10 K-file (Dentsply Maillefer, Ballaigues, Switzerland) and served as the gold standard.

Results

The mean absolute difference of the CBCT-based root canal length from the gold standard was 0.46 mm (95% confidence interval, 0.41–0.50 mm). Only in 9 of 198 (4.5%) roots did the difference between the CBCT-based root canal length and the gold standard exceed 1 mm.

Conclusions

CBCT-based root canal length measurements are accurate and reliable when compared with a gold standard.     

Transesophageal echocardiography in patients less than 60 years of age without obvious cardiac source of embolism

Abstract

Minor potential cardioembolic sources of stroke such as atrial septal aneurysms (ASA) or patent foramen ovale (PFO) are important risk factors for cryptogenic stroke. We aim to determine the prevalence of these abnormalities through an exhaustive etiological workup including transesophageal echocardiography and cervical arteries assessment in stroke patients younger than 60 years of age who had no evidence of a significant source of embolism. We classified 118 stroke patients into four groups according to transesophageal echocardiography (TEE) and cervical arteries assessment findings. Group A, consisted of 30 (25.4%) patients who had an arteriopathy likely related to stroke without any cardiac abnormality; Group B, 49 (41%) patients who had only a potential cardiac source; Group C, 9 (7.6%) patients who had an obvious arterial source of stroke and incidental cardiac abnormalities, and Group D, 30 (25.4%) patients who had neither cardiac nor arterial source. Data were analysed with X2 test for the comparison of risk factors between groups. Variance analysis was used to compare age between groups. Significance was assessed as p <0.05. ASA represented 56.8% of the cardiac abnormalities and was diagnosed in 35.4% of the 79 patients who had an unexplained stroke (B and D). A PFO was found in 34.1% of the patients who had a cryptogenic stroke (B and D). According to Fisher's exact test, ASA was significantly associated to PFO (p"0.001). According to this selection one fourth of the patients might have a truly cryptogenic stroke as the etiological workup failed to demonstrate any source of stroke. Comparison between groups showed that the patients in whom an arterial source was detected also had a potential cardioembolic source in 23% of the cases (G), versus 62% in patients who had no arterial source (B and D) (p = 0.0007). Our study confirmed the strong association between ASA, PFO and stroke. Although there was a lower incidence of minor potential cardioembolic sources in patients who had a cervical artery disease, we suggest a systematic TEE screening in all patients with stroke without major cardiac source, in order to ensure a better prevention. [Neurol Res 1995; 17: 368-372]