Stefan Tigges

Emory University | EU · Department of Radiology and Imaging Sciences

Objective: The purpose was to evaluate reader variability between experienced and in-training radiologists of COVID-19 pneumonia severity on CXR, and to create a multi reader database suitable for AI development. Methods: In this study, CXRs from PCR positive COVID-19 patients were reviewed. Six experienced cardiothoracic radiologists and two re...

The adage "a picture is worth a thousand words" holds true in medicine, especially so in radiology. Although the images radiologists interpret are highly detailed, there often is no substitute for a concise diagrammatic illustration. Medical illustrations can help to clarify anatomy, pathology, and procedures-relaying complex information in a simpl...

Purpose: Proper selection of imaging examinations and basic image interpretation skills are essential for all physicians, yet only approximately 25% of US medical schools require clerkships in radiology. Although there is limited time in most medical school curricula to allow the addition of a required radiology clerkship, the authors developed on...

Purpose: Simulation has been used as an educational and assessment tool in several fields, generally involving training of physical skills. To date, simulation has found limited application in teaching and assessment of skills related to image perception and interpretation. The goal of this pilot study was to evaluate the feasibility of simulation...

The variability in medical imaging evaluation across US medical schools inspired leading radiology student educators to develop the Alliance of Medical Student Educators in Radiology (AMSER) Standardized Exam (SE). This examination tests the understanding of essential material and concepts which are endorsed by the AMSER National Medical Student Cu...

Abstract Introduction The study of evidence-based medicine involves complex statistical concepts. One of the most challenging aspects for students is the transition from simplified explanatory examples of such topics to analysis of their application in clinical research. This module bridges that gap and guides the progression from following step-by...

Abstract Introduction The study of evidence-based medicine involves complex statistical concepts. One of the most challenging aspects for students is the transition from simplified explanatory examples of such topics to analysis of their application in clinical research. This module serves to bridge that gap and guides the progression from followin...

PURPOSE/AIM Purpose/Aim: To present essential features of sensitivity, specificity, ROC curves, positive and negative predictive value in an easy to understand way using a visual approach. CONTENT ORGANIZATION Our exhibit is a general education review. An understanding of diagnostic test metrics like sensitivity, specificity, positive/negative pr...

Accurate coronary artery calcium scoring improves risk stratification in some strata of the population. We evaluated individual and combined effects of reader experience, heart rate, vessel displacement, and trajectory on computed tomography (CT) Agatston score, calcium volume, and calcium mass in a cardiac phantom model. A cardiac motion phantom w...

To evaluate relative detection of pulmonary embolism (PE) with standard bolus-triggered contrast-enhanced breath-hold magnetic resonance (MR) pulmonary angiography, contrast-enhanced recirculation-phase breath-hold low-flip angle three-dimensional (3D) gradient-echo (GRE), and nonenhanced free-induction cardiac- and respiratory-triggered true fast...

Sind gegenwärtige dramatisch geprägte Theaterformen ein ästhetisches Auslaufmodell oder lässt sich vielmehr von einer »Renaissance des dramatischen Dramas« (Haas 2007, 177) sprechen, was auch auf erste Ermüdungserscheinungen postdramatisch-performativer Schreib- und Spielformen hinweisen könnte? Ist es aufgrund der Disparatheit heutiger transversal...

PURPOSE We evaluated individual and combined effects of heart rate (HR), coronary artery displacement, vessel trajectory and reader experience on computed tomography (CT) Calcium score (CS). METHOD AND MATERIALS Eight explanted coronary arteries (CA) were secured to a cardiac phantom that simulated characteristic motion of the CA. The phantom was...

Stent placement is commonly used for the treatment of obstructive coronary artery disease. Initially, bare-metal stents were deployed to maintain vessel patency, but 21–36% of these stents developed in-stent re-stenosis (ISR) due to neointimal hyperplasia [1,2]. Neointimal hyperplasia is a normal reparative process that occurs after stent deploymen...

To evaluate effect of different kVp, reconstruction kernels and contrast concentrations on stent luminal diameter measurements and luminal contrast attenuation values. Two metallic coronary stents (2.75 mm and 3.0 mm) were deployed in silicone tubes and tubes were filled with diluted iodinated contrast (1:20 dilution of Iohexol 350 mg% to achieve a...

PURPOSE/AIM 1.To describe various image post-processing techniques for MDCT coronary angiography 2.To show the strengths, pitfalls and limitations of each post-processing technique CONTENT ORGANIZATION •Highlight several post-processing techniques for MDCT coronary angiography, such as multiplanar reconstructions (MPR), curved planar reconstructio...

Cardiac computed tomography (CT) scans can produce enormous datasets (>3,000 images), making traditional axial image interpretation un-workable. Previously existing and new techniques including multiplanar reformats, volume rendering, maximum intensity projections, curved multiplanar reformats, and "4D" (time-resolved) methods have all been used to...

The postprocessing of multidetector row computed tomography (MDCT) data sets is best termed "volume interrogation." Most techniques are best applied as problem-solving tools rather than as preset protocols, and radiologist involvement is essential. The ability to interact with an isotropic or nearly isotropic data set in near real-time is a tremend...

To determine the frequency, diagnostic yield, outcomes, cost, and rate of false-positive results of routine chest radiography performed in asymptomatic patients in the primary care setting. Radiography reports on all patients who underwent routine or screening posteroanterior and lateral chest radiography at a university-affiliated primary care cli...

PURPOSE Purpose: Thoracic radiography is one of the most commonly performed diagnostic tests, with over 112 million chest x-rays obtained in 2000. The diagnostic yield and cost of �routine� or screening chest radiography in asymptomatic primary care patients is unknown. The purpose of our study was to determine the frequency, yield, outcome, and di...

The purpose of this study was to assess the need for conventional radiographs of the thoracic spine for routine clearance of trauma patients in whom chest CT has revealed no spinal trauma. The study was in the form of a retrospective review of trauma patients over the previous five years who underwent conventional radiographs of the thoracic spine...

Our purpose was to assess the incremental effect of maximum-intensity-projection (MIP) image processing on the ability of various observers to detect small (<1 cm in diameter) central and peripheral lung nodules revealed by multidetector CT. We retrospectively identified 25 patients with metastatic disease, each having from two to nine nodules that...

We sought to characterize demographics and injury patterns among patients undergoing emergency department cervical spine radiography for blunt traumatic injury. All patients with blunt trauma undergoing cervical spine radiography at 21 centers were enrolled in this prospective, observational study. Patients' date of birth, age, sex, and ethnicity w...

Previous studies of cervical spine injury involve individual institutions or special populations. There is currently little reliable information regarding natural cervical spine injury patterns after blunt trauma. This substudy of the National Emergency X-Radiography Utilization Study project was designed to accurately assess the prevalence, spectr...

Purpose: To determine whether adoption of the Ottawa knee rule will decrease the cost of evaluating adult patients with acute blunt knee trauma compared with not using the rule. Materials and methods: A decision tree was constructed with two arms, one that included explicit use of the Ottawa knee rule and another that did not include adoption of th...

The objective of this study was to determine the proportion of radiologists in three different radiology organizations who report using the American College of Radiology (ACR) musculoskeletal appropriateness criteria. Radiologists from the Society of Skeletal Radiology, Georgia Radiological Society, and Utah Radiological Society were surveyed regar...

Injuries to the knee and tibial/fibular shafts are extremely common, with knee injuries alone accounting for over 1.3 million emergency department visits yearly in the United States. Many of these injuries will present with straightforward radiographic findings, but others will have a subtle or complex appearance. This article reviews injuries of t...

We evaluated the Ottawa knee rules in a high-volume teaching hospital in the United States to determine whether the rules could be safely used to decide whether patients with acute blunt knee trauma should undergo radiography. During a 13-month period, 378 patients with acute blunt knee trauma were prospectively examined using the Ottawa knee rules...

This report describes a case in which significant cervical spine injuries were demonstrated only on the upright lateral view. On occasion, unstable or potentially unstable cervical spine injuries may only be seen on an upright lateral view.

Suspected cruciate ligament injury is a common indication for obtaining knee radiographs and MRI examinations. Radiologists should be familiar with plain film signs as well as direct and indirect MRI findings of injury. In addition, radiologists should recognize the normal and abnormal appearance of cruciate ligament grafts, especially ACL repairs,...

To evaluate the accuracy of direct magnetic resonance imaging (MRI) signs of tears of the anterior cruciate ligament. Over the period April 1991 to February 1994, 92 consecutive MRI studies of the knee were obtained for which arthroscopic data were also available. The MRI studies were retrospectively evaluated for course, continuity, signal intensi...

Although magnetic resonance imaging is the most accurate imaging method of evaluating the anterior cruciate ligament, several plain radiographic signs suggestive of anterior cruciate ligament injury have been described. Plain radiographs also play an important role in evaluating anterior cruciate ligament reconstruction.

Many severe knee injuries may have only subtle plain radiographic findings. Their detection is more easily accomplished if attention is paid to a few key anatomic sites.

Evaluation of plain radiographs of the knee in the trauma setting is facilitated by knowing certain features of normal bony and soft-tissue anatomy. Subtle abnormalities are most easily recognized when normal features and variants of normal anatomy are well understood. In addition, several inconspicuous but important signs of injury can be recogniz...

Our purpose was to determine the discovery method and stage of newly discovered breast cancers at two different medical centers. To do this, we conducted a retrospective chart review at our urban and suburban teaching hospitals during 1991 through 1992 and 1992, respectively. Only 29 (26%) of 112 cancers at our urban hospital were discovered mammog...

To report cases of osteonecrosis in patients who were HIV positive but had no apparent risk factors for osteonecrosis. A computer search of records from two university-affiliated teaching hospitals yielded eight cases of osteonecrosis in HIV-positive patients and patients with AIDS. The patients' charts and radiographic records were reviewed to det...

Musculoskeletal complications in patients with chronic renal failure are common and may be related to the disease itself or to treatment. The altered metabolism in patients with chronic renal failure leads to renal osteodystrophy, which consists of osteomalacia and secondary hyperparathyroidism [1]. Erosive changes attributable to secondary hyperpa...

To determine whether findings on plain radiographs alter clinical care in outpatient management after hip arthroplasty. From June 1, 1993, through February 28, 1994, one arthroplasty surgeon saw 148 outpatients (age range, 15-86 years) after hip arthroplasty (163 prostheses). The surgeon made decisions about clinical management before he reviewed t...

Aggressive granulomatosis is a potentially devastating complication of joint-replacement surgery. This condition likely represents a foreign body reaction to particulate metal, methylmethacrylate or polyethylene. The authors describe a 51-year-old woman in whom aggressive granulomatosis developed after total knee arthroplasty. Plain radiographs ove...

The purpose of this study was to evaluate the spectrum of plain radiographic findings in patients with septic hip prostheses. Radiographs of 20 confirmed infected hip prostheses were examined for the presence or absence of lucency, type of lucency (focal or nonfocal), rapidity of radiographic change, periostitis, subsidence, and cement fracture. Fi...

The technique of hip arthroplasty is at least 30 years old and currently is performed 120,000 times per year in the United States [1]. Changes in materials and surgical techniques have markedly decreased the prevalence of infection and aseptic loosening. At the same time, other complications such as stress shielding and aggressive granulomatosis ha...

The accuracy of fluoroscopy-guided hip aspiration in the diagnosis of infection in hip prostheses was evaluated. Results from 147 preoperative aspiration cultures were compared with results of operative cultures. The relative costs of aspiration and nuclear medicine studies were also compared. With the operative culture results as the standard, sen...

We present a case of spontaneous resolution of a nuchal cystic hygroma in a fetus with a normal karyotype. This unusual case is important in the counseling of patients with affected fetuses, since the transitory nature of the disease is not well known.

PURPOSE/AIM 1) Review cardiac electrical and mechanical sequences, the twisting motion of the heart and normal coronary anatomy/motion. 2) Understand the relationship between cardiac and coronary motion. 3) Show how knowledge of cardiac and vessel motion is used to anticipate and minimize motion artifact to improve coronary CTA accuracy. CONTENT O...

PURPOSE/AIM 1.To describe radiation dose associated with MDCT coronary angiography and catheter angiography 2.To illustrate clinical strategies and technological innovations for reducing the radiation dose associated with MDCT coronary angiography CONTENT ORGANIZATION •Provide a perspective on radiation dose associated with coronary imaging with s...

PURPOSE/AIM 1.To discuss the anatomy of coronary arteries and veins on MDCT and to illustrate the appearance of cardiac chambers, valves 2.To show the significance of various views necessary for evaluation of coronary anatomy by MDCT CONTENT ORGANIZATION •To illustrate coronary vascular anatomy with state-of-the-art MDCT coronary angiography with...

PURPOSE/AIM 1.To discuss artifacts produced by coronary stents on MDCT 2.To describe trouble shooting options to improve stent visualization by MDCT CONTENT ORGANIZATION •Illustrate stent related artifacts and limitations in coronary MDCT angiography with help of suitable clinical examples and phantom studies •Options to reduce coronary stent rela...

PURPOSE/AIM 1.To describe imaging techniques for evaluation of coronary artery anomalies 2.To describe the various types and imaging features of coronary artery anomalies on multi-detector row CT angiography CONTENT ORGANIZATION •This educational exhibit will describe several types of coronary anomalies •We will illustrate the MDCT angiographic fe...

1 Eher interessiert mich die Abwesenheit von dramatischen Äußerungen. (Jürgen Gosch) Warum soll im Kontext von gegenwärtigen Schreib-und Aufführungsstra-tegien von dramatischen Transformationen die Rede sein, wenn sich doch längst – nicht nur in terminologischer Hinsicht – für Text und Bühne die von Hans-Thies Lehmann entwickelte flexible Arbeitsfo...