Stable patients with suspected myocardial ischemia: comparison of machine-learning computed tomography-based fractional flow reserve and stress perfusion cardiovascular magnetic resonance imaging to detect myocardial ischemia.

BACKGROUND: Machine-Learning Computed Tomography-Based Fractional Flow Reserve (CT-FFRML) is a novel tool for the assessment of hemodynamic relevance of coronary artery stenoses. We examined the diagnostic performance of CT-FFRML compared to stress perfusion cardiovascular magnetic resonance (CMR) and tested if there is an additional value of CT-FFRML over coronary computed tomography angiography (cCTA). METHODS: Our retrospective analysis included 269 vessels in 141 patients (mean age 67 ± 9 years, 78% males) who underwent clinically indicated cCTA and subsequent stress perfusion CMR within a period of 2 months. CT-FFRML values were calculated from standard cCTA. RESULTS: CT-FFRML revealed no hemodynamic significance in 79% of the patients having ≥ 50% stenosis in cCTA. Chi2 values for the statistical relationship between CT-FFRML and stress perfusion CMR was significant (p < 0.0001). CT-FFRML and cCTA (≥ 70% stenosis) provided a per patient sensitivity of 88% (95%CI 64-99%) and 59% (95%CI 33-82%); specificity of 90% (95%CI 84-95%) and 85% (95%CI 78-91%); positive predictive value of 56% (95%CI 42-69%) and 36% (95%CI 24-50%); negative predictive value of 98% (95%CI 94-100%) and 94% (95%CI 90-96%); accuracy of 90% (95%CI 84-94%) and 82% (95%CI 75-88%) when compared to stress perfusion CMR. The accuracy of cCTA (≥ 50% stenosis) was 19% (95%CI 13-27%). The AUCs were 0.89 for CT-FFRML and 0.74 for cCTA (≥ 70% stenosis) and therefore significantly different (p < 0.05). CONCLUSION: CT-FFRML compared to stress perfusion CMR as the reference standard shows high diagnostic power in the identification of patients with hemodynamically significant coronary artery stenosis. This could support the role of cCTA as gatekeeper for further downstream testing and may reduce the number of patients undergoing unnecessary invasive workup.

The role of radiology in provenance research - experiences from the collaboration between radiology and anatomy at the University of Rostock and future perspectives.

Worldwide, the study and examination of human remains and the circumstances of their acquisition for anatomical collection have received great interest. As part of provenance research projects, a large number of collections are being investigated to determine whether the human remains have been acquired in a correct or unlawful way because the people could have been killed in order to be used as "anthropological objects" for research purposes and to become so-called "specimens". These topics have also been addressed by the Institute of Anatomy at the University Medical Center Rostock. The role of radiology in this interdisciplinary project will be presented using selected examples.The anatomical collection at the University of Rostock includes 40 human skulls, 14 plaster casts, 6 Egyptian mummy heads, and 1 full-body mummy. In addition to the examination by a historian, an anthropologist, and forensic pathologists, additional computed tomography was carried out on nine skulls and the full-body mummy. Micro-computed tomography was also carried out on seven skulls in order to enable a look behind the mummification material and tissue remains.(Micro-)computed tomography was able to close diagnostic gaps and the results presented some rather unexpected findings.Due to interdisciplinary collaboration, individual fates could be determined, which provided information about the individual's life and death circumstances. None of the examined individuals showed evidence of colonial-era injustice or the use of violence that would have led to their inclusion in the collection. (Micro-)computed tomography was a valuable addition to this provenance research project. · Computed tomography enhances interdisciplinary provenance research projects.. · Computed tomography enables a non-destructive examination of human remains.. · The future of research and presentation of human remains will increasingly be virtual.. · Steinhagen I, Brinker U, Kolbe V et al. The role of radiology in provenance research - experiences from the collaboration between radiology and anatomy at the University of Rostock and future perspectives. Fortschr Röntgenstr 2024; DOI 10.1055/a-2303-0312.

Simultaneous assessment of heart and lungs with gated high-pitch ultra-low dose chest CT using artificial intelligence-based calcium scoring.

Purpose: The combined testing for coronary artery and pulmonary diseases is of clinical interest as risk factors are shared. In this study, a novel ECG-gated tin-filtered ultra-low dose chest CT protocol (GCCT) for integrated heart and lung acquisition and the applicability of artificial intelligence (AI)-based coronary artery calcium scoring were assessed. Methods: In a clinical registry of 10481 patients undergoing heart and lung CT, GCCT was applied in 44 patients on a dual-source CT. Coronary calcium scans (CCS) with 120 kVp, 100 kVp, and tin-filtered 100 kVp (Sn100) of controls, matched with regard to age, sex, and body-mass index, were retrieved from the registry (ntotal=176, 66.5 (59.4-74.0) years, 52 men). Automatic tube current modulation was used in all scans. In 20 patients undergoing GCCT and Sn100 CCS, Agatston scores were measured both semi-automatically by experts and by AI, and classified into six groups (0, <10, <100, <400, <1000, ≥1000). Results: Effective dose decreased significantly from 120 kVp CCS (0.50 (0.41-0.61) mSv) to 100 kVp CCS (0.34 (0.26-0.37) mSv) to Sn100 CCS (0.14 (0.11-0.17) mSv). GCCT showed higher values (0.28 (0.21-0.32) mSv) than Sn100 CCS but lower than 120 kVp and 100 kVp CCS (all p < 0.05) despite greater scan length. Agatston scores correlated strongly between GCCT and Sn100 CCS in semi-automatic and AI-based measurements (both ρ = 0.98, p < 0.001) resulting in high agreement in Agatston score classification (κ = 0.97, 95% CI 0.92-1.00; κ = 0.89, 95% CI 0.79-0.99). Regarding chest findings, further diagnostic steps were recommended in 28 patients. Conclusions: GCCT allows for reliable coronary artery disease and lung cancer screening with ultra-low radiation exposure. GCCT-derived Agatston score shows excellent agreement with standard CCS, resulting in equivalent risk stratification.

Factors influencing the safety of outpatient coronary CT angiography: a clinical registry study.

OBJECTIVES: Since the safety of coronary CT angiography (CTA) is of great importance, especially with regard to widening indications and increasing morbidity, the aim of this study was to assess influencing factors. METHODS: Patients undergoing coronary CTA in a third-generation dual-source CT in a radiological centre were included in a clinical registry. Up to 20 mg metoprolol was administered intravenously to attain a heart rate ≤65/min. Glyceryl trinitrate (GTN) was administered in doses of 0.8 mg and 0.4 mg. Blood pressure was measured before the administration and after the CTA. RESULTS: Out of 5500 consecutive patients (3194 men, 62.3 (54.9-70.0) years), adverse events occurred in 68 patients (1.2%) with mild anaphylactoid reactions (0.4%), vasovagal symptoms (0.3%) and extravasation (0.3%) being most frequent. Anti-allergic drugs were given in 17 patients, atropine in 3 patients and volume in 1 patient. Drug administration resulted in a significant mean arterial pressure decline (96.0 (88.3-106.0) vs 108.7 (99.7-117.3) mmHg; p<0.001). Patients who suffered systolic blood pressure drops >20 mmHg or >40 mmHg were older (66.5 (58.6-73.3) vs 60.5 (53.6-68.3) years; 70.2 (63.3-76.5) vs 62.1 (54.7-69.6) years), more often male (65.1% vs 54.4%; 68.9% vs 57.3%) and had higher Agatston score equivalents (83.0 (2.0-432.0) vs 15.0 (0.0-172.0); 163.0 (16.3-830.8) vs 25.0 (0.0-220.0); all p<0.001). GTN dose reduction lowered the fraction of patients suffering from blood pressure drops >20 mmHg or >40 mmHg from 34.5% to 27.4% and from 6.1% to 3.5% (both p<0.001), respectively. The proportion of coronary segments with impaired image quality did not differ significantly. CONCLUSIONS: Coronary CTA with intravenous beta-blocker administration is a safe procedure in an outpatient setting as adverse events are rare and mostly mild. Reduced GTN doses can further improve safety by lowering the rate of significant blood pressure drops, which occurred especially in elderly men with increased plaque burden. TRIAL REGISTRATION NUMBER: NCT03815123.

Extended reality visualization of medical museum specimens: Online presentation of conjoined twins curated by Dr. Jacob Henle between 1844-1852.

Background: The purpose of this study is to characterize a full-term conjoined twins' cadaver curated by Dr. Jacob Henle sometime between 1844 and 1852 and demonstrate digital distribution of an old and rare medical museum specimen using an extended reality (XR) model workflow. Methods: The cadaver (Preparation 296) is in the Department of Anatomy and Cell Biology at the University of Heidelberg. An XR display workflow comprises image capture, segmentation, and visualization using CT/MR scans derived from the cadaver. Online radiology presentation to medical students focuses on diagnostic characteristics of anatomical systems depicted with XR models. Results: Developmental defects in Preparation 296 include duplicated supradiaphragmatic structures and abnormal osteological features. Subdiaphragmatically, the gut is continuous on the right, but terminates at the distal esophagus on the left. One large liver occupies the abdomen with one spleen located on the left side. Observations suggest duplication of the primitive streak and separate notochords rostrally. Duplication occurs near the yolk sac and involves midgut formation while secondary midline fusion of the upper extremities and ribs likely results from the proximity of the embryos during development. Medical students access the model with device agnostic software during the curricular topic "Human Body Plan" that includes embryology concepts covering mechanisms of twinning. Conclusions: The workflow enables ease-of-access XR visualizations of an old and rare museum specimen. This study also demonstrates digital distribution and utilization of XR models applicable to embryology education.

Unique paleopathology in a pre-Columbian mummy remnant from Southern Peru--severe cervical rotation trauma with subluxation of the axis as cause of death.

We describe the multidisciplinary findings in a pre-Columbian mummy head from Southern Peru (Cahuachi, Nazca civilisation, radiocarbon dating between 120 and 750 AD) of a mature male individual (40-60 years) with the first two vertebrae attached in pathological position. Accordingly, the atlanto-axial transition (C1/C2) was significantly rotated and dislocated at 38° angle associated with a bulging brownish mass that considerably reduced the spinal canal by circa 60%. Using surface microscopy, endoscopy, high-resolution multi-slice computer tomography, paleohistology and immunohistochemistry, we identified an extensive epidural hematoma of the upper cervical spinal canal-extending into the skull cavity-obviously due to a rupture of the left vertebral artery at its transition between atlas and skull base. There were no signs of fractures of the skull or vertebrae. Histological and immunohistochemical examinations clearly identified dura, brain residues and densely packed corpuscular elements that proved to represent fresh epidural hematoma. Subsequent biochemical analysis provided no evidence for pre-mortal cocaine consumption. Stable isotope analysis, however, revealed significant and repeated changes in the nutrition during his last 9 months, suggesting high mobility. Finally, the significant narrowing of the rotational atlanto-axial dislocation and the epidural hematoma probably caused compression of the spinal cord and the medulla oblongata with subsequent respiratory arrest. In conclusion, we suggest that the man died within a short period of time (probably few minutes) in an upright position with the head rotated rapidly to the right side. In paleopathologic literature, trauma to the upper cervical spine has as yet only very rarely been described, and dislocation of the vertebral bodies has not been presented.

Short-Time Changes in Coronary Artery Plaques Assessed by Follow-Up Coronary CT Angiography-Characteristics and Impact on Patient Management.

Background: Coronary artery disease (CAD) shows a chronic but heterogeneous clinical course. Coronary CT angiography (CTA) allows for the visualization of the entire coronary tree and the detection of early stages of CAD. The aim of this study was to assess short-time changes in non-calcified and mixed plaques and their clinical impact using coronary CTA in a real-world setting. Methods: Between 11/2014 and 07/2019, 6,701 patients had a coronary CTA with a third-generation dual-source CT, of whom 77 patients (57 males, 63.8 ± 10.8 years) with a chronic CAD received clinically indicated follow-up CTA. Non-calcified and mixed plaques were analyzed in 1,211 coronary segments. Patients were divided into groups: stable, progressive, or regressive plaques. Results: Within the follow-up period of 22.3 ± 10.4 months, 44 patients (58%) showed stable plaques, 27 (36%) showed progression, 5 (7%) showed regression. One patient was excluded due to an undetermined CAD course showing both, progressive and regressive plaques. Age did not differ significantly between groups. Patients with plaque regression were predominantly female (80 vs. 20%), whereas patients showing progression were mainly male (85 vs. 15%; p < 0.01 for both). Regression was only observed in patients with mild CAD or one-vessel disease. The follow-up CTA led to changes in patient management in the majority of subjects (n = 50; 66%). Conclusions: Changes in coronary artery plaques can be observed within a short period resulting in an adjustment of the clinical management in the majority of CAD patients. Follow-up coronary CTA renders the non-invasive assessment of plaque development possible and allows for an individualized diagnostics and therapy optimization.

Limits of the possible: diagnostic image quality in coronary angiography with third-generation dual-source CT.

BACKGROUND: The usage of coronary CT angiography (CTA) is appropriate in patients with acute or chronic chest pain; however the diagnostic accuracy may be challenged with increased Agatston score (AS), increased heart rate, arrhythmia and severe obesity. Thus, we aim to determine the potential of the recently introduced third-generation dual-source CT (DSCT) for CTA in a 'real-life' clinical setting. METHODS: Two hundred and sixty-eight consecutive patients (age: 67 ± 10 years; BMI: 27 ± 5 kg/m²; 61% male) undergoing clinically indicated CTA with DSCT were included in the retrospective single-center analysis. A contrast-enhanced volume dataset was acquired in sequential (SSM) (n = 151) or helical scan mode (HSM) (n = 117). Coronary segments were classified in diagnostic or non-diagnostic image quality. A subset underwent invasive angiography to determine the diagnostic accuracy of CTA. RESULTS: SSM (96.8 ± 6%) and HSM (97.5 ± 8%) provided no significant differences in the overall diagnostic image quality. However, AS had significant influence on diagnostic image quality exclusively in SSM (B = 0.003; p = 0.0001), but not in HSM. Diagnostic image quality significantly decreased in SSM in patients with AS ≥2,000 (p = 0.03). SSM (sensitivity: 93.9%; specificity: 96.7%; PPV: 88.6%; NPV: 98.3%) and HSM (sensitivity: 97.4%; specificity: 94.3%; PPV: 86.0%; NPV: 99.0%) provided comparable diagnostic accuracy (p = n.s.). SSM yielded significantly lower radiation doses as compared to HSM (2.1 ± 2.0 vs. 5.1 ± 3.3 mSv; p = 0.0001) in age and BMI-matched cohorts. CONCLUSION: SSM in third-generation DSCT enables significant dose savings and provides robust diagnostic image quality in patients with AS ≤2000 independent of heart rate, heart rhythm or obesity.

Early depictions of the human anterior nasal septum.

In the literature, remarks on the depiction of the anterior nasal septum in prehistoric times cannot be found. Studying works of art from some archaeological sites of Asia, Asia Minor, Near East, Egypt, and Southeastern Europe the anatomical depiction of the columella and the nostrils in human figures are shown. These figures or heads, partly appearing as masks, were made of ivory, stone, marble, terracotta, steatite, reeds and clay, or of burned limestone. Faces and figures sculpted in the time between the Upper Palaeolithic (30,000 - 25,000 BC) and the Early Bronze Age (3,300 - 2,400 BC) are presented as examples of our ancestors' outstanding skill to create works of art with an astonishing ability to observe anatomical details. The tendency to create a human nose in a natural manner can already be recognized in the figurines of the Upper Palaeolithic.

Cribra orbitalia visualized in computed tomography.

Cribra orbitalia are sieve-like lesions of the orbital roof. While common in historic skulls, they have long been absent in those examined in the last decades. Only recently we found low-grade cribra orbitalia in some contemporary cases. Though of unknown origin, this lesion is often attributed to anemia and deficiency diseases. It is theoretically possible to visualize cribra orbitalia in living subjects by computed tomography and thus study their etiology. The aim of our study was to investigate the possibilities of computed tomography for visualizing cribra orbitalia. We used multislice computed tomography (MSCT) in the spiral and sequential mode to image medium-grade cribra orbitalia of moderate severity in a human skull. Virtual endoscopic and 3-D images were produced by post-processing. The best results were obtained by the sequential mode and 3-D reconstruction. Given a thin slice thickness and a wide slice angle between slice plane and the orbital roof, the threshold level seems to be the most important factor influencing realistic reproduction and should be finely adjusted according to bone density. Clinical research may now begin by examining relevant patients undergoing CT.

[Value of spiral CT and MRI (1.5 T) in preoperative diagnosis of tumors of the head of the pancreas]. / Wertigkeit von Spiral-CT und MRT (1,5T) zur präoperativen Diagnostik von Pankreaskopftumoren.

OBJECTIVE: Prospective comparison study of helical computed tomography (HCT) and magnetic resonance imaging (MRI, 1.5-tesla field strength) with regard to their role in planning surgical therapy in a defined, homogeneous patient collective with tumors of the pancreatic head. PATIENTS AND METHODS: Sixty-one patients with clinical/ultrasound evidence of tumor were examined by HCT and MRI. Findings were compared with surgical anatomy and histology using a data documentation sheet. Factors evaluated included the malignancy of the tumors and the probability of correct diagnosis in relation to tumor size, as well as the occurrence of lymph node and distant metastases, arterial and portal-venous infiltration, extrapancreatic infiltration, determination of resectability and tumor staging (TNM classification). These factors were compared on the basis of their respective sensitivity, specificity, negative and positive predictive value and accuracy. RESULTS: Malignancy was correctly diagnosed by HCT and MRI in 82% and 77%, respectively, with a corresponding sensitivity for malignancy of 86% and 68%. Tumors with diameters > 2 cm were detected in 100% of cases by HCT and in 88% by MRI, while tumors with diameters < 2 cm were correctly diagnosed by HCT and MRI in 60% and 40% of cases. Respective rates of correct diagnosis by HCT and MRI were 80% and 66% for extrapancreatic infiltration; 76% and 79% for pancreatic cysts; 87% and 87% for calcifications; and 77% and 92% for atrophy. The diagnostic accuracy for vascular infiltration by HCT and MRI stood at 59% and 77% with sensitivities of 88% and 75%, respectively. Local resectability was correctly determined by HCT in 71%, by MRI in 62% of cases. Lymph node metastases were correctly identified by HCT and MRI with an accuracy of 76% and 72%, while distant metastases were correctly diagnosed by HCT and MRI with an accuracy of 93% and 93%. Correct T stage was identified by HCT in 66%, by MRI in 60%. HCT tended to assign patients to a higher T stage than later determined by surgery and/or histology. CONCLUSION: Our data do not indicate a clear superiority for either HCT or MRI in the diagnosis of pancreatic malignancies.