Rainer Rienmueller

Rainer Rienmueller
Medical University of Graz · Abteilung für allgemeine radiologische Diagnostik

About

142
Publications
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Introduction

Publications

Publications (142)
Article
Full-text available
Registration of dynamic CT image sequences is a crucial preprocessing step for clinical evaluation of multiple physiological determinants in the heart such as global and regional myocardial perfusion. In this work, we present a deformable deep learning-based image registration method for quantitative myocardial perfusion CT examinations, which in c...
Article
Full-text available
The success rate of percutaneous coronary artery intervention (PCI) of chronic total occlusion (CTO) lesions have increased in the recent years. However, improvement of function is only possible when significant myocardial viability is present. One of the most important factors of maintaining myocardial viability is the opening and development of c...
Conference Paper
Multislice CT is considered an upcoming technology for the non-invasive quantification of myocardial blood flow in patients with Coronary Artery Disease (CAD). For this purpose, the heart of the patient is imaged in 3D for several heart beats after contrast agent administration. This approach requires to define a specific workflow taking into accou...
Conference Paper
Full-text available
Multislice CT is considered an upcoming technology for the non-invasive quantification of myocardial blood flow in patients with Coronary Artery Disease (CAD). For this purpose, the heart of the patient is imaged in 3D for several heart beats after contrast agent administration. This approach requires to define a specific workflow taking into accou...
Poster
Full-text available
The purpose of this study is to evaluate the range of possible reduction of Iodine concentration in animal experiments for quantitative evaluation of myocardial perfusion. In clinical settings, quantitative estimation of myocardial perfusion is important not only in the evaluation of regional and global changes of perfusion caused by solitary or mu...
Poster
Full-text available
In the daily clinical settings, there is increasing awareness for the need to know the individual myocardial perfusion quantitatively in ml/100g/min. This is not only important in the evaluation of perfusion defects of solitary or multiple coronary stenosis lesions but also for the understanding of myocardial perfusion changes related to general at...
Article
Full-text available
Computed tomography (CT) is considered an upcoming technology for the quantitative estimation of myocardial perfusion (MPF). Based on previous results that affirm the feasibility of estimating global MPF using a CT scanner in an animal model, this work evaluates the computation of MPF in patients by comparing two different mathematical approaches b...
Article
In accidents resulting in severe injuries, a clinical forensic examination is generally abandoned in the initial phase due to high-priority clinical needs. However, in many cases, data from clinical computed tomography (CT) examinations are available. The goals of this prospective study were (a) to evaluate clinical CT data as a basis for forensic...
Article
Background: X-linked myopathy with postural muscle atrophy is a novel X-linked myopathy caused by mutations in the four-and-a-half LIM domain 1 gene (FHL1). Cardiac involvement was suspected in initial publications. We now systematically analyzed the association of the FHL1 genotype with the cardiac phenotype to establish a potential cardiac invol...
Article
Introduction: Constrictive pericarditis is a rare cause for heart failure. Symptoms resemble those of other causes, but patients do not respond accordingly to administered medication. The diagnosis is complicated and often those patients aquire diseases secondary to their heart failure. Case report: We report a patient with recurrent pericardial an...
Article
Formation of chambers in the bovine uterus during early pregnancy A comparison between morphological, ultrasonic and nuclear magnetic resonance findings In the bovine, the uterus shows prominent circular folds during early pregnancy. These folds protrude into the lumen nearly at right angles to the uterine wall and, reaching a height of about 2–3 c...
Article
Pulmonary artery intimal sarcoma is a rare tumor of the cardiovascular system. Intimal sarcoma of the pulmonary valve itself has not been described. Embolization into pulmonary arteries originating from the pulmonary valve intimal sarcoma can mimic chronic thromboembolic pulmonary hypertension and mislead the diagnosis. We present and discuss a pat...
Article
The aims of this study were to measure the size of Lister's Tubercle, the extent of the extensor pollicis longus (EPL) groove and the dihedral angle of the distal dorsal radius. Computer tomography scans of 30 forearms were performed by using a 64-slice Siemens SOMATOM Sensation CT system (Resolution 0.6 mm). DICOM raw data were calculated to 3D by...
Presentation
Full-text available
Abstracts of platform presentations of 2009 EACA meeting.
Article
To assess morphologically a transmeatal approach to the lateral and superior ampullary nerves performable under local anesthesia and simultaneously with the existing approach to the singular nerve developed by Gacek during the same operation. Eighty halves of human heads preserved with the Thiel method were operated on by an otologist. Two surgical...
Article
This study evaluated arterial wall stiffness independent of variant background blood pressure. A new technique-arterial wall stiffness index (AWSI)-was developed and its use verified. Intraluminal pressure and luminal volume were measured on eight swine descending aortas. AWSI was formulated to evaluate absolute arterial wall stiffness independent...
Article
Pulmonary hypertension is a disease characterized by an elevation in pulmonary arterial pressure that is diagnosed invasively via right heart catheterization. Such pathological altered pressures in the pulmonary vascular system should lead to changes in blood flow patterns in the main pulmonary artery. Forty-eight subjects (22 with manifest pulmona...
Article
Pulmonary hypertension is a life-threatening chronic disorder of the pulmonary circulation. Elevated pressure and resistance in the pulmonary vessels lead to progressive right heart failure which results in functional limitations and ultimately the death of most patients. Thus, the monitoring of right ventricular (RV) function is of great importanc...
Article
Full-text available
To evaluate aortic wall stiffness without influence of different background blood pressure, a new technique was developed and verified. At eight swine descending aortae, volume-pressure measurement was performed using custom-made system. Based on averaged pressure-volume curve, aortic distensibility index was formulated to evaluate aortic wall stif...
Article
Orientation-related monoleaflet mechanical valve flow and velocity studies in the downstream are limited in mitral valve replacement studies. In five sheep, ventricular blood flow was visualized prior to the implantation of a Medtronic Hall tilting valve model. In six sheep, the implant orientation was either anatomical (disc aligned with the anter...
Article
Full-text available
Results of short- and midterm follow-up studies of the patency rate of the Symmetry aortic connector systems (St Jude Medical, Inc, Minneapolis, Minn) are controversial. Long-term follow-up studies are still lacking (so far, the longest mean follow-up period was 19 months). The aim of our study was (1) to evaluate the patency rate of this device ov...
Article
Introduction: Orientation-related mechanical valve flow and velocity studies in the downstream area are limited in mitral valve replacement studies. Objective: In five sheep, ventricular blood flow was visualized prior to implantation of mitral Edwards Bileaflet Mechanical Valve and a Medtronic Hall tilting valve prosthesis. Implant orientation was...
Article
The clinical role of magnetic resonance in diseases of the heart and great vessels is rapidly evolving. Cardiovascular magnetic resonance (CMR) has become an established non-invasive imaging modality for the assessment of various cardiac disorders, such as congenital heart disease, cardiac masses, cardiomyopathies, aortic and pericardial diseases....
Article
Methodological comparison of ellipsoid model-based approaches and Simpson method to evaluate left ventricular volumetric parameters by magnetic resonance (MR) and electron beam tomography (EBT) and analysis of the origin of possible discrepancies. 100 subjects (87 patients, 13 healthy volunteers) were studied in MR in various cardiac views and EBT...
Article
An easy applicable method for pre-operative port position planning for totally endoscopic coronary artery bypass (TECAB) grafting based on magnetic resonance (MR) coronary angiography and image post-processing is introduced and analyzed. For this, combined left main (LM) and left anterior descending (LAD) coronary arteries of 21 subjects (14 patien...
Article
The diagnosis and therapy of pericardial diseases are still a physician's challenge. Advanced CT and MR imaging technologies can display the complete morphology of the heart and the pericardium and of the adjacent thoracic structures with a spatial and contrast resolution below 1 mm. All the macromorphologic determinants of pericardial constriction...
Article
Guidelines and Expert Consensus documents aim to present all the relevant evidence on a particular issue in order to help physicians to weigh the benefits and risks of a particular diagnostic or therapeutic procedure. They should be helpful in everyday clinical decision-making. A great number of Guidelines and Expert Consensus Documents have been...
Article
Genetic variants of the angiotensin-converting enzyme (ACE) cascade may influence left ventricular myocardial mass (LVMM) regression after aortic valve surgery. Postoperative long-term changes in LV indices were investigated in patients with asymptomatic aortic regurgitation (AR) and symptomatic aortic stenosis (AS) and related to alleles of ACE po...
Article
The identification of the ideal anastomosis site and the proper port placement are critical for the success of closed-chest robotic surgery. We investigated a new systematic procedure for precise port placement for TECABs. We used trigonometry and a human thoracic model to determine the optimal working angles between anastomotic plane, instruments,...
Article
Purpose: A brief summary of past, present, and future of cardiac CT is given. PAST: As long as the CT exposure time was in a range between 1 and 5 s, it was only possible to image cardiac morphology. At that time, we have learned the diagnostic criteria of transverse cardiac imaging especially in the field of pericardial diseases. Diagnostic crite...
Article
Stenosis or obstruction of the sinus node artery (SNA) of the heart can cause cardiac arrhythmia and even sudden death. The purpose of this study was to evaluate the detectability of the SNA using electron beam computed tomography (EBCT). Eighty patients (mean age: 61 +/- 10 years, range: 31-80 years) were examined with ECG-triggered EBCT (exposure...
Chapter
Based on more than 2000 cardiac EBT studies using the above mentioned protocol it is possible like in an “One-Stop-Shop” to assess the extent of coronary atherosclerosis as Coronary Calcium Score (first part of the definition of coronary heart disease) to evaluate the degree, location and number of stenotic lesions in the proximal 5–6cm of the coro...
Article
Electron-beam computed tomography-derived coronary calcium score correlates with the morphologic severity of coronary artery disease, reflecting both global atherosclerotic plaque formation and coronary artery luminal narrowing. The current study examines the impact of coronary atherosclerotic plaque burden, measured by coronary calcium score, on t...
Article
A cubital intravenous iodine contrast agent enhancement is used to visualize coronary arteries using EBT. The quality of the coronary artery visualization however is limited by the nearly simultaneous approximation of CT values in coronary arteries and myocardial tissue. The objective of the study was to evaluate if "under real clinical circumstanc...
Article
Left ventricular hypertrophy in patients with critical aortic stenosis (AS) is an adaptive process that compensates for high intracavitary pressure and reduces systolic wall stress followed by an increase in myocardial masses. In the present prospective clinical trial, we investigated long-term compensatory changes in left ventricular geometry and...
Article
Pulmonary vascular resistance is of special interest in many diseases. Usually it is determined invasively by catheterization, but cardiac output and pulmonary transit time can be ascertained by several noninvasive methods. Fourteen heart recipients (age 34-71 years) were examined by electron-beam CT of the heart. Cine and flow studies were perform...
Chapter
The introduction and the continuous improvement of digital imaging techniques as digital radiography, computed tomography, magnetic resonance and ultrasound with permanent shortening of the image exposure time enable not only qualitative morphological statements but also functional analysis as quantification of function, bloodflow and perfusion bas...
Article
A humanoid thorax phantom containing six compartments was scanned with two different computed tomography (CT) scanners using various image acquisition and reconstruction parameters. The differences of CT numbers were statistically significant between the two CT scanners for each compartment (p<0.001) except for the "air" compartment. The variabilit...
Article
This study describes the appearance of the coronary sinus and its tributary veins as visualized on ECG-triggered electron-beam computed tomography (CT) and investigates their spatial relationship to other cardiac structures. Thirty-two patients were examined with ECG-triggered electron-beam CT (exposure time: 100 ms, slice thickness: 1.5 mm) after...
Article
Full-text available
To evaluate the appearance of the pericardial sinuses and recesses at electrocardiographically triggered electron-beam computed tomography (CT). Findings in 100 patients without known pericardial disease were reviewed. The patients underwent electron-beam CT of the heart because of suspected coronary arterial disease. Incremental electrocardiograph...
Article
The purpose of this study was to evaluate the pharmacokinetics of abdominal time-attenuation curves obtained at electron-beam tomography. Computed tomographic enhancement data of the aorta, portal vein, vena cava, liver, spleen, and pancreas were obtained in 25 patients after injection of 50 mL of contrast medium. These data were used to calculate...
Chapter
The aim of the study was to compare the findings of EBCT with those of Tl-201-scintigraphy. 12 patients with CAD were investigated. The 14 fixed Tl-defects were associated with coronary artery stenosis of more than 50% in 5 cases, with atherosclerotic plaques in 2 cases. The 7 non-persisting defects were associated with coronary artery stenosis of...
Article
Venous air embolism has been reported as a complication of invasive diagnostic and therapeutic procedures or accidental trauma. Little is known about the incidence of air embolism after minimal intravenous manipulations, such as the insertion of a peripheral intravenous cannula. Small air emboli in the central veins, central arteries, and cardiac c...
Article
Using electron-beam computed tomography (EBCT) with short exposure times of 100 or 50 ms and the capability of acquiring up to 2 x 17 images/s it is possible to study most of the important morphological and functional determinants of the heart. Various examples of studies in acute and chronic cardiac diseases are shown to demonstrate the use of EBC...
Article
Myocardial perfusion is one of the most important functional parameters of the heart. Presently various indirect methods are used to determine coronary blood flow or myocardial perfusion as inertgas-, thermodilution-, Doppler catheter- and radiopharmacological techniques. Electron-beam-computed-tomographical technology is able to perform CT data ac...
Article
Myocardial perfusion is one of the most important functional parameters of the heart. Presently various indirect methods are used to determine coronary blood flow or myocardial perfusion as inertgas-, thermodilution-, Doppler catheter- and radiopharmacological techniques. Electron-beam-computed-tomographical technology is able to perform CT data ac...
Article
To determine the frequency and location of venous air emboli that occur with the use of electron-beam computed tomographic (CT) studies of the chest. Findings from 677 patients who underwent chest electron-beam CT with intravenous administration of contrast material were reviewed. Unenhanced CT studies were performed in 127 (18.8%) of these patient...
Article
Using electron-beam computed tomography (EBCT) with short exposure times of 100 or 50 ms and the capability of acquiring up to 2 x 17 images/s it is possible to study most of the important morphological and functional determinants of the heart. Various examples of studies in acute and chronic cardiac diseases are shown to demonstrate the use of EBC...
Article
Functional evaluation of swallowing disorders requires rapid imaging modalities. Videofluorography and cinematography are the gold standard, but they have their limitations: no transverse plane imaging is achieved and structural resolution for exact topographic analysis is limited. Three cases preselected by videofluorography were studied to evalua...
Article
Videofluorographie und Kinematographie gelten derzeit als Goldstandard für die Abklärung von Schluckstörungen. Methodisch bedingt ist jedoch keine überlagerungsfreie Darstellung der anatomisch wichtigen Strukturen des Pharynx möglich, so daß bei manchen Störungen nicht unterschieden werden kann, ob diese pathoanatomisch oder funktionell-neurogen be...
Article
Full-text available
Eight patients with known focal nodular hyperplasia (FNH) were studied by electron beam tomography (EBT) in a multisection flow mode at defined time intervals after intravenous contrast agent injection. Various regions of interest (ROIs) were defined in the areas of FNH, normal liver parenchyma, aorta and portal vein. In each ROI density changes we...
Article
Assessment of lung attenuation by CT reflects changes in the air-to-tissue ratio of the lung. We have analyzed the interdependence of intrathoracic gas volume, lung morphology, and functional disorder by high resolution CT (HRCT) to assess quantitative disease threshold in obstructive and restrictive diffuse lung disease. Pulmonary HRCT was perform...
Article
To determine the value of digital storage-phosphor radiography (SR) on the detection and identification of subtle lung nodules, postero-anterior (PA) and lateral (LAT) film-screen (FR) chest radiographs were compared with isodose SR images of 45 patients with metastatic malignancies. The SR postprocessing was done with a particular mode previously...
Article
Bronchoalveolar lavage (BAL) has gained widespread use as a tool for investigating human lung diseases. In certain cases, it can be useful to obtain BAL material in a serial manner. There is convincing evidence from experimental and clinical studies that BAL can cause influx of neutrophils into the bronchoalveolar space. However, conflicting data h...
Chapter
Noninvasive in vivo assessment of lung density and structure by quantitative computed tomography (QCT) has a long tradition in the scientific literature. Early efforts were limited, however, as reproducibility was insufficient due to a lack of respiratory control during scanning and appropriate evaluation software was missing (e.g. Goddard et al. 1...
Article
Eighty patients with pericardial constriction confirmed by catheter data were studied by CT (n = 79), MR imaging (n = 24), or both. To determine the validity of these imaging methods for subsequent treatment, 30 patients' studies were evaluated retrospectively (1980-1984) and 50 (1985-1991) prospectively. Twenty patients from the first group and 30...
Article
Eighty patients with pericardial constriction confirmed by catheter data were studied by CT (n = 79), MR imaging (n = 24), or both. To determine the validity of these imaging methods for subsequent treatment, 30 patients' studies were evaluated retrospectively (1980-1984) and 50 (1985-1991) prospectively. Twenty patients from the first group and 30...
Article
Atrial fibrillation occurred in a 27-year-old patient with a history of globular cardiac enlargement since childhood. Because of the probable causal relationship between the preexisting heart disease-which was supposed to be an enlargement of the left atrium-and the rhythm disturbance, we recommended a surgical intervention. Cardiac surgery reveale...
Chapter
In diffuse pulmonary diseases it has been shown [1] that histogram analysis of frequencies of values determined by spirometrically standardized high resolution computed tomography (HRCT) provides objective quantitative data that reflect changes of pulmonary structures corresponding to lung function impairments.
Chapter
In a preliminary experimental study to characterize the influence of air pollution on the behaviour of the airways and lung parenchyma, high resolution computed tomography (CT) studies of the lungs of beagle dogs were performed. The purpose of this study was to establish the exact relationship between CT values of the lungs at different levels of r...
Article
The spectrum of diagnostic procedures in cardiology has been decisively extended by magnetic resonance (and also by ultrafast computed tomography) because of its superior visualization of morphological (myocardium, pericardium) and functional (LVMM/EDV) parameters. The continuous development of faster echo sequences makes it possible to perform hea...
Article
Twenty-seven patients with diffuse fibrosing alveolitis (DFA), 27 patients with granulomatous lung disease (GLD), 3 patients with homozygous alpha 1-proteinase inhibitor deficiency (alpha 1-PID), and 6 healthy volunteers (C) were studied using thin section high resolution CT (HRCT) at 50% of actual vital capacity (VC), determined and controlled spi...
Article
Although echocardiography is mostly applied for the diagnosis of heart tumors there are restrictions concerning the representation of the mediastinal and cardial topography in spite of the usage of transoesophageal echocardiography. Computed tomography (CT) and magnetic resonance imaging (MR) are able to give a full representation of the heart and...