Perfusion-weighted imaging in vestibular schwannoma: the influence that cystic status and tumor size have on perfusion profiles.

Objective: The perfusion profile of vestibular schwannomas (VSs) and the factors that influence it have yet to be determined. Materials and Methods: Twenty patients with sporadic VS were analyzed by calculating parameters related to the extravascular extracellular space (EES)-the volume transfer constant between a vessel and the EES (Ktrans); the EES volume per unit of tissue volume (Ve); and the rate transfer constant between EES and blood plasma (Kep)-as well as the relative cerebral blood volume (rCBV), and by correlating those parameters with the size of the tumor and its structure (solid, cystic, or heterogeneous). Results: Although Ktrans, Ve, and Kep were measurable in all tumors, rCBV was measurable only in large tumors. We detected a positive correlation between Ktrans and rCBV (r = 0.62, p = 0.031), a negative correlation between Ve and Kep (r = -0.51, p = 0.021), and a positive correlation between Ktrans and Ve only in solid VSs (r = 0.64, p = 0.048). Comparing the means for small and large VSs, we found that the former showed lower Ktrans (0.13 vs. 0.029, p < 0.001), higher Kep (0.68 vs. 0.46, p = 0.037), and lower Ve (0.45 vs. 0.83, p < 0.001). The mean Ktrans was lower in the cystic portions of cystic VSs than in their solid portions (0.14 vs. 0.32, p < 0.001), as was the mean Ve (0.37 vs. 0.78, p < 0.001). There were positive correlations between the solid and cystic portions for Ktrans (r = 0.71, p = 0.048) and Kep (r = 0.74, p = 0.037). Conclusion: In VS, tumor size appears to be consistently associated with perfusion values. In cystic VS, the cystic portions seem to have lower Ktrans and Ve than do the solid portions.

Objetivo: O perfil de perfusão do schwannoma vestibular (SV) não tem sido estudado, nem os fatores que o influenciam. Materiais e Métodos: Vinte pacientes com SV esporádico foram analisados usando Ktrans, Ve, Kep e rCBV e correlacionados com tamanho e estádio cístico. Resultados: Ktrans, Ve e Kep foram medidos em todos os casos. rCBV só foi possível em tumores grandes. Ktrans e rCBV estavam correlacionados positivamente (r = 0,62, p = 0, 0 31 ) . Ve e Kep estavam negativamente correlacionados (r = ­0,51, p = 0,021). Ktrans estava correlacionado positivamente com Ve em SVs sólidos (r = 0,64, p = 0,048). Em SVs pequenos, Ktrans foi menor (0,13 vs 0,029, p < 0,001), Kep foi maior (0,68 vs 0,46, p = 0,037) e Ve foi menor (0,45 vs 0,83, p < 0,001) que nos SVs grandes. Ktrans e Ve foram menores dentro dos cistos que nas porções solidas dos SVs císticos (0,14 vs 0,32, p < 0,001; 0,37 vs 0,78, p < 0.001, respectivamente). Foi encontrada correlação positiva em Ktrans (r = 0,71, p = 0,048) e Kep (r = 0,74, p = 0,037) entre as áreas sólidas e císticas. Conclusão: Nos SVs, o tamanho está consistentemente associado com os valores da perfusão. Nos SVs císticos, as porções císticas parecem ter valores menores de Ktrans e Ve do que nas porções sólidas.

Perfusion-weighted imaging in vestibular schwannoma: the influence that cystic status and tumor size have on perfusion profiles / Perfusão por ressonância magnética em schwannoma vestibular: influência do tamanho e estádio cístico no perfil da perfusão

Abstract Objective: The perfusion profile of vestibular schwannomas (VSs) and the factors that influence it have yet to be determined. Materials and Methods: Twenty patients with sporadic VS were analyzed by calculating parameters related to the extravascular extracellular space (EES)—the volume transfer constant between a vessel and the EES (Ktrans); the EES volume per unit of tissue volume (Ve); and the rate transfer constant between EES and blood plasma (Kep)—as well as the relative cerebral blood volume (rCBV), and by correlating those parameters with the size of the tumor and its structure (solid, cystic, or heterogeneous). Results: Although Ktrans, Ve, and Kep were measurable in all tumors, rCBV was measurable only in large tumors. We detected a positive correlation between Ktrans and rCBV (r = 0.62, p = 0.031), a negative correlation between Ve and Kep (r = -0.51, p = 0.021), and a positive correlation between Ktrans and Ve only in solid VSs (r = 0.64, p = 0.048). Comparing the means for small and large VSs, we found that the former showed lower Ktrans (0.13 vs. 0.029, p < 0.001), higher Kep (0.68 vs. 0.46, p = 0.037), and lower Ve (0.45 vs. 0.83, p < 0.001). The mean Ktrans was lower in the cystic portions of cystic VSs than in their solid portions (0.14 vs. 0.32, p < 0.001), as was the mean Ve (0.37 vs. 0.78, p < 0.001). There were positive correlations between the solid and cystic portions for Ktrans (r = 0.71, p = 0.048) and Kep (r = 0.74, p = 0.037). Conclusion: In VS, tumor size appears to be consistently associated with perfusion values. In cystic VS, the cystic portions seem to have lower Ktrans and Ve than do the solid portions.

Resumo Objetivo: O perfil de perfusão do schwannoma vestibular (SV) não tem sido estudado, nem os fatores que o influenciam. Materiais e Métodos: Vinte pacientes com SV esporádico foram analisados usando Ktrans, Ve, Kep e rCBV e correlacionados com tamanho e estádio cístico. Resultados: Ktrans, Ve e Kep foram medidos em todos os casos. rCBV só foi possível em tumores grandes. Ktrans e rCBV estavam correlacionados positivamente (r = 0,62, p = 0, 0 31 ) . Ve e Kep estavam negativamente correlacionados (r = -0,51, p = 0,021). Ktrans estava correlacionado positivamente com Ve em SVs sólidos (r = 0,64, p = 0,048). Em SVs pequenos, Ktrans foi menor (0,13 vs 0,029, p < 0,001), Kep foi maior (0,68 vs 0,46, p = 0,037) e Ve foi menor (0,45 vs 0,83, p < 0,001) que nos SVs grandes. Ktrans e Ve foram menores dentro dos cistos que nas porções solidas dos SVs císticos (0,14 vs 0,32, p < 0,001; 0,37 vs 0,78, p < 0.001, respectivamente). Foi encontrada correlação positiva em Ktrans (r = 0,71, p = 0,048) e Kep (r = 0,74, p = 0,037) entre as áreas sólidas e císticas. Conclusão: Nos SVs, o tamanho está consistentemente associado com os valores da perfusão. Nos SVs císticos, as porções císticas parecem ter valores menores de Ktrans e Ve do que nas porções sólidas.

Gadolinium-Based Contrast Agents: Updates and Answers to Typical Questions Regarding Gadolinium Use.

Gadolinium-based contrast agents have expanded the diagnostic usefulness and capability of magnetic resonance imaging. Despite their highly favorable safety profile, these agents have been associated with nephrogenic systemic fibrosis in a small number of patients who have advanced kidney disease. Recently, trace amounts of gadolinium deposition in the brain and other organs have been reported after contrast exposure, even in patients with normal renal function. In this review, we provide a brief overview of recent updates and discuss typical clinical situations related to the use of gadolinium-based contrast agents.

Serum iron and vitamin B 12 deficiency could indicate celiac disease by flexible spectral imaging color enhancement

SUMMARY INTRODUCTION Celiac disease (CeD) is an autoimmune disease that can be delayed in diagnosis due to the presence of atypical and asymptomatic cases in adulthood. Herein we aimed to study the frequency of CeD and evaluate whether magnified endoscopy and magnified/FICE (flexible spectral imaging color enhancement) techniques contribute to the diagnosis in patients with serum iron and vitamin B12 deficiency. METHODS We evaluated 50 adult patients (10 males and 40 females) who had serum iron and vitamin B12 deficiency, prospectively. All the patients had undergone upper gastrointestinal system endoscopy by the same endoscopist. The second part of the duodenum was evaluated with white light, magnified, and magnified/FICE endoscopy. Biopsy specimens were evaluated by the same pathologist. The specimens diagnosed as CeD were classified according to the Modified Marsh-Oberhuber criteria. RESULTS 10 of 50 patients (20%) were diagnosed as CeD. The average age was 41±11 years (20-67 years). Thirty percent of CeD diagnosed patients had typical CeD symptoms. Six of 10 patients (60%) who were diagnosed as CeD had typical endoscopic images under white lighted endoscopy. All of these 10 patients (100%) showed villous irregularity, partial villous atrophy, or total villous atrophy consistent with CeD with magnified and magnified/FICE endoscopy. CONCLUSION The practical use of magnified/FICE endoscopy allows us to differentiate mucosal abnormalities of the duodenum and minimize false-negative results that indicate normal mucosal findings with conventional endoscopy.

RESUMO INTRODUÇÃO A doença celíaca (DC) é uma doença autoimune que pode ter seu diagnóstico atrasado devido à presença de casos atípicos e assintomáticos na idade adulta. Neste trabalho, objetivamos estudar a frequência de DC e avaliar se as técnicas de endoscopia magnificada e magnificada/Fice (flexible spectral imaging color enhancement) contribuem para o diagnóstico em pacientes com deficiência sérica de ferro e vitamina B12. MÉTODO Foram avaliados prospectivamente 50 pacientes adultos (10 homens e 40 mulheres) com deficiência sérica de ferro e vitamina B12. Todos os pacientes foram submetidos a endoscopia digestiva alta pelo mesmo endoscopista. A segunda parte do duodeno foi avaliada com endoscopia com luz branca, magnificada e magnificada/Fice. As amostras de biópsia foram avaliadas pelo mesmo patologista. Os espécimes diagnosticados como DC foram classificados de acordo com os critérios de Marsh-Oberhuber modificado. RESULTADOS Dez dos 50 pacientes (% 20) foram diagnosticados como DC. A idade média foi de 41±11 anos (20-67 anos). Trinta por cento dos pacientes diagnosticados com DC apresentaram sintomas típicos de DC. Seis dos dez pacientes (60%) diagnosticados com DC tinham imagens endoscópicas típicas sob endoscopia de luz branca. Todos esses dez pacientes (% 100) apresentaram irregularidade das vilosidades, atrofia das vilosidades parciais ou atrofia das vilosidades totais consistentes com a DC com endoscopia magnificada e magnificada/Fice. CONCLUSÃO O uso prático da endoscopia magnificada/Fice permite diferenciar anormalidades mucosas do duodeno e minimizar os resultados falso-negativos que apresentam achados mucosais normais com a endoscopia convencional.

Endoscopic image enhancement with noise suppression.

Stereoscopic endoscopes have been used increasingly in minimally invasive surgery to visualise the organ surface and manipulate various surgical tools. However, insufficient and irregular light sources become major challenges for endoscopic surgery. Not only do these conditions hinder image processing algorithms, sometimes surgical tools are barely visible when operating within low-light regions. In addition, low-light regions have low signal-to-noise ratio and metrication artefacts due to quantisation errors. As a result, present image enhancement methods usually suffer from heavy noise amplification in low-light regions. In this Letter, the authors propose an effective method for endoscopic image enhancement by identifying different illumination regions and designing the enhancement design criteria for desired image quality. Compared with existing image enhancement methods, the proposed method is able to enhance the low-light region while preventing noise amplification during image enhancement process. The proposed method is tested with 200 images acquired by endoscopic surgeries. Computed results show that the proposed algorithm can outperform state-of-the-art algorithms for image enhancement, in terms of naturalness image quality evaluator and illumination index.

Detecting Acute Myocardial Infarction by Diffusion-Weighted versus T2-Weighted Imaging and Myocardial Necrosis Markers.

We used a porcine model of acute myocardial infarction to study the signal evolution of ischemic myocardium on diffusion-weighted magnetic resonance images (DWI). Eight Chinese miniature pigs underwent percutaneous left anterior descending or left circumflex coronary artery occlusion for 90 minutes followed by reperfusion, which induced acute myocardial infarction. We used DWI preprocedurally and hourly for 4 hours postprocedurally. We acquired turbo inversion recovery magnitude T2-weighted images (TIRM T2WI) and late gadolinium enhancement images from the DWI slices. We measured the serum myocardial necrosis markers myoglobin, creatine kinase-MB isoenzyme, and cardiac troponin I at the same time points as the magnetic resonance scanning. We used histochemical staining to confirm injury. All images were analyzed qualitatively. Contrast-to-noise ratio (the contrast between infarcted and healthy myocardium) and relative signal index were used in quantitative image analysis. We found that DWI identified myocardial signal abnormity early (<4 hr) after acute myocardial infarction and identified the infarct-related high signal more often than did TIRM T2WI: 7 of 8 pigs (87.5%) versus 3 of 8 (37.5%) (P=0.046). Quantitative image analysis yielded a significant difference in contrast-to-noise ratio and relative signal index between infarcted and normal myocardium on DWI. However, within 4 hours after infarction, the serologic myocardial injury markers were not significantly positive. We conclude that DWI can be used to detect myocardial signal abnormalities early after acute myocardial infarction-identifying the infarction earlier than TIRM T2WI and widely used clinical serologic biomarkers.

Prompt Recognition of Left Ventricular Free-Wall Rupture Aided by the Use of Contrast Echocardiography.

In the modern period of reperfusion, left ventricular free-wall rupture occurs in less than 1% of myocardial infarctions. Typically, acute left ventricular free-wall rupture leads to sudden death from immediate cardiac tamponade. We present the case of a 59-year-old woman who sustained a posterior-wall myocardial infarction and subsequent cardiac arrest with pulseless electrical activity. A bedside transthoracic echocardiogram showed pericardial effusion with cardiac tamponade. Emergency pericardiocentesis yielded 500 mL of blood, and spontaneous circulation returned. Contrast-enhanced echocardiograms revealed inferolateral akinesis and a new, small myocardial slit with systolic extrusion of contrast medium, consistent with left ventricular free-wall rupture. During immediate open-heart surgery, a small hole in an area of necrotic tissue was discovered and repaired. This case highlights the usefulness of bedside contrast-enhanced echocardiography in confirming acute left ventricular free-wall rupture and enabling rapid surgical treatment.

The Preoperative Evaluation of Infective Endocarditis via 3-Dimensional Transesophageal Echocardiography.

Transesophageal echocardiography continues to have a central role in the diagnosis of infective endocarditis and its sequelae. Recent technological advances offer the option of 3-dimensional imaging in the evaluation of patients with infective endocarditis. We present an illustrative case and review the literature regarding the potential advantages and limitations of 3-dimensional transesophageal echocardiography in the diagnosis of complicated infective endocarditis. A 51-year-old man, an intravenous drug user who had undergone bioprosthetic aortic valve replacement 5 months earlier, presented with prosthetic valve endocarditis. Preoperative transesophageal echocardiography with 3D rendition revealed a large abscess involving the mitral aortic intervalvular fibrosa, together with a mycotic aneurysm that had ruptured into the left atrium, resulting in a left ventricle-to-left atrium fistula. Three-dimensional transesophageal echocardiography enabled superior preoperative anatomic delineation and surgical planning. We conclude that 3-dimensional transesophageal echocardiography can be a useful adjunct to traditional 2-dimensional transesophageal echocardiography as a tool in the diagnosis of infective endocarditis.

Use of Tomosynthesis for Detection of Bone Erosions of the Foot in Patients With Established Rheumatoid Arthritis: Comparison With Radiography and CT.

OBJECTIVE: The purpose of this study was to compare tomosynthesis with radiography for the detection of bone erosions of the foot in patients with established rheumatoid arthritis (RA) using MDCT as a reference standard. SUBJECTS AND METHODS: Eighteen consecutive patients with established RA were included. Each patient underwent radiography, tomosynthesis, and CT examinations of the feet on the same day. Two radiologists independently determined the number of bone erosions and the Sharp-van der Heijde score with each of the three imaging modalities. RESULTS: On a total of 216 joints from 18 patients, 216 bone erosions were detected on CT, 215 on tomosynthesis, and 181 with radiography. The mean (± SD) Sharp-van der Heijde score was equivalent for tomosynthesis (18.8 ± 16.8) and CT (19.8 ± 18.5) but was statistically lower for radiography (16.4 ± 18.0) (p = 0.030). The respective overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for tomosynthesis were 80%, 75%, 78%, 76%, and 80%, whereas the respective corresponding values for radiography were 66%, 81%, 74%, 77%, and 71%. The radiation burden of tomosynthesis was almost equivalent to that of radiography. CONCLUSION: Tomosynthesis has a higher sensitivity than radiography to detect bone erosions of the foot in patients with established RA and imparts an almost equivalent radiation burden.

Application of contrast ultrasound in diagnosis of orbital neoplasms / 中华实验眼科杂志

Background Orbital tumor has complex histological types and it is difficult for clinical differential diagnosis.Therefore, it is badly in need of a new diagnostic technology to distinguish its benign and malignancy.Objective This study aimed to analyze and compare the characteristics of contrast ultrasound image between benign and malignant orbital neoplasms and evaluate the diagnostic value of contrast ultrasound to orbital tumor.Methods The clinical data of 24 patients with malignant orbital neoplasms and 51 patients with benign orbital neoplasms were retrospectively analyzed in Taihe Hospital of Hubei University of Medicine from September 2010 to September 2013.Contrast ultrasound examination was carried out on all the patients using MyLab Twice color ultrasonic device under the informed consent.SonoVue solution of 2.0 ml was intravenously injected and then the state and dynamic graphs of orbital tumors were collected.According to the classification of enhanced levels and patterns,the imaging features of orbital neoplasms were evaluated, and time-intensity curve (TIC) and dynamic vascular pattern (DVP) curve were obtained with SonoLiver software.The general ultrasonic signs and contrast ultrasonic characteristics between benign and malignant neoplasms were compared.Results Hyper-enhanced lesions were found in 62.5％ (15/24) and 27.5％ (14/51) ,and iso-intensity lesions were found in 20.8％ (5/24) and 49.0％(25/51) in the malignant orbital neoplasm patients and benign ones, respectively, with a significant difference in enhanced types between them (x2 =26.40,P＜0.01).Based on the enhanced mode, heterogeneity enhancement lesions were found in 75.0％ (18/24) and 25.5％ (13/51), and hemogeneity enhancement lesions were seen in 25.0％(6/24) and 47.1％ (24/51) in the malignant orbital neoplasm patients and benign ones, respectively, showing a significant differnee between them (x2 =30.40, P ＜ 0.01).The 58.3％ patients showed rapid rising and sharp descending TIC curves,and 75.0％ patients showed the biphasic wave DVP curves in the malignant lesions;while in the benign lesions,the TIC curves of 78.7％ patients were quick lift and slow dessend, and the DVP curves of 74.5 ％patients appeared to be positive phasic wave.These curve features were significantly different between the malignant lesions and benign ones (TIC:Z=-3.130,P=0.002;DVP:Z =-4.730,P =0.000).Conclusions Contrastultrasound examination shows that different tissue-derived orbital neoplasms have varied enhanced modes and types.Contrast-ultrasound examination is helpful for the differential diagnosis of orbital neoplasms.

Circumferential stent fracture: novel detection and treatment with the use of StentBoost.

Circumferential stent fracture is extremely uncommon, and in rare cases, it can cause stent thrombosis. Recognizing stent fracture can be difficult on conventional fluoroscopy because of poor stent radiopacity. We found that StentBoost image acquisition yields improved visibility of stent struts, enabling the identification of stent fracture and the precise positioning of new stents over previously stented segments.We report the case of a 50-year-old man who presented with acute myocardial infarction and subacute stent thrombosis a week after percutaneous transluminal coronary angioplasty and placement of a bare-metal stent. The new lesion was crossed with a guidewire, but multiple attempts to advance a balloon catheter were unsuccessful. Live StentBoost image acquisition revealed circumferential stent fracture into 2 separate sections, with abnormal angulation between the proximal and distal portions of the stent. With StentBoost guidance, the wire and balloon catheter were both easily manipulated to cross the lesion, and angioplasty and restenting were completed with good results.StentBoost can be a useful adjunctive tool for the cardiac interventionist during complex percutaneous transluminal coronary angioplasty, and it was invaluable in this challenging situation. We discuss stent fracture and the benefits of using StentBoost in such situations.

Accuracy of automated attenuation-based 3-dimensional segmentation: in the analysis of left ventricular function compared with magnetic resonance imaging.

We evaluated attenuation-based 3-dimensional segmentation for the analysis of left ventricular function, using as our standard of reference magnetic resonance imaging and dual-source computed tomography with traditional short-axis planimetry.Twenty patients with known or suspected coronary artery disease were examined prospectively. In all magnetic resonance and computed tomographic datasets, global functional values were determined by 2-dimensional planimetry. Computed tomographic scans were further evaluated by automated 3-dimensional segmentation, and the results were compared by Pearson correlation and Bland-Altman analysis.Agreement between magnetic resonance imaging and dual-source computed tomographic 2-dimensional planimetry was good for all values (end-diastolic volume, bias= -4.2, r=0.99; end-systolic volume, bias= -1.7, r=0.99, stroke-volume, bias= -2.4, r=0.98; ejection fraction, bias=0.26, r=0.94; and myocardial mass, bias= 2.5, r=0.90). By contrast, dual-source computed tomographic 3-dimensional segmentation overestimated end-diastolic volume (bias= -19.1, P <0.001), stroke-volume (bias= -16.9, P <0.001), and myocardial mass (bias= -34.4, P <0.001). Moreover, correlation with magnetic resonance imaging proved disappointing for ejection fraction (r=0.72). Results were similar in a direct comparison between dual-source computed tomographic 2-dimensional planimetry and 3-dimensional segmentation (end-diastolic volume, bias= -14.9, r=0.94; end-systolic volume, bias= -0.5, r=0.90; stroke volume, bias= -14.5, r=0.83; ejection fraction, bias= -2.8, r=0.74; and myocardial mass, bias= -36.8, r=0.79).Due to significant overestimation of volumes and poor correlation of ejection fraction with cine magnetic resonance imaging results, attenuation-based 3-dimensional segmentation compares unfavorably with traditional planimetry. Hence this method should be used with caution, and its time benefits should be weighed against its imprecision of functional analysis.

Metastatic carcinoid tumor obstructing left ventricular outflow.

Cardiac tumors are rare and usually indicate metastatic disease. Characterizing a tumor and reaching an exact diagnosis can be difficult. Diagnosis has been aided greatly by advances in imaging, such as cardiovascular magnetic resonance with the use of gadolinium-pentetic acid. Carcinoid tumors are neuroendocrine neoplasms that are found most often in the intestinal tract, although they can also develop in the lung, stomach, or heart. Herein, we report the case of a 72-year-old woman with a history of intestinal carcinoid disease and presenting symptoms of dizziness, fatigue, and chest pain. We used cardiovascular magnetic resonance with gadolinium enhancement to identify a large mass obstructing left ventricular outflow. The histopathologic results of an endomyocardial biopsy confirmed that the mass was a left-sided metastatic carcinoid cardiac tumor. To our knowledge, we are reporting the 1st combined use of clinical evaluation, cardiovascular magnetic resonance, and histopathologic studies to reach such a diagnosis.

Delayed gadolinium enhancement in the atrial wall: a novel finding in 3 patients with rheumatic heart disease.

Carditis is a well-recognized finding in rheumatic heart disease and is one of the major criteria in the diagnosis of rheumatic fever. Cardiovascular magnetic resonance with gadolinium enhancement has been used in the evaluation of several disease entities, most commonly in the imaging of myocardial infarctions. We retrospectively evaluated cardiovascular magnetic resonance studies within our institution to identify patients with rheumatic heart disease. Herein, we report the cases of 3 patients who had clinical and imaging findings of rheumatic heart disease, and in whom cardiovascular magnetic resonance revealed delayed gadolinium enhancement in the walls of 1 or both atria. In 1 patient, the delayed enhancement was also evident in both atrioventricular valves.To our knowledge, this is the 1st report of atrial-wall or atrioventricular-valve delayed gadolinium enhancement in the presence of rheumatic heart disease. Further studies may clarify whether atrial delayed gadolinium enhancement is seen in rheumatic heart disease more often than in other diseases that cause atrial fibrillation, and the diagnostic and prognostic significance of such a finding.