Run-Off Computed Tomography Angiography (CTA) for Discriminating the Underlying Causes of Intermittent Claudication

Aim To evaluate run-off computed tomography angiography (CTA) of abdominal aorta and lower extremities for detecting musculoskeletal pathologies and clinically relevant extravascular incidental findings in patients with intermittent claudication (IC) and suspected peripheral arterial disease (PAD). Does run-off CTA allow image-based therapeutic decision making by discriminating the causes of intermittent claudication in patients with suspected peripheral arterial disease PAD? Material and Methods Retrospective re-evaluation of CTAs performed in patients with acute or chronic intermittent claudication (i.e., Fontaine stages I to IIB) between January 2005 and October 2013. Allocation to one of three categories of underlying causes of IC symptoms: vascular, musculoskeletal (MSK) or both. Clinically relevant extravascular incidental findings were evaluated. Medical records were reviewed to verify specific therapies as well as main and incidental findings. Results While focused on vascular imaging, CTA image quality was sufficient for evaluation of the MSK system in all cases. The underlying cause of IC was diagnosed in run-off CTA as vascular, MSK and a combination in n = 138 (65%), n = 10 (4%), and n = 66 (31%) cases, respectively. Specific vascular or MSK therapy was recorded in n = 123 and n = 9 cases. In n = 82, no follow-up was possible. Clinically relevant extravascular incidental findings were detected in n = 65 patients (30%) with neoplasia, ascites and pleural effusion being the most common findings. Discussion Run-off CTA allows identification of vascular, MSK, and combined causes of IC in patients with suspected PAD and can guide specific therapy. CTA also allowed confident detection of crEVIF although detection did not necessarily trigger workup or treatment

Diagnostic Confidence of Run-Off CT-Angiography as the Primary Diagnostic Imaging Modality in Patients Presenting with Acute or Chronic Peripheral Arterial Disease

Objectives To investigate the reliability of CT-angiography of the lower extremities (run-off CTA) to derive a treatment decision in patients with acute and chronic peripheral artery disease (PAD). Materials and Methods 314 patients referred for run-off CTA were includ-ed in this retrospective study. First, diagnostic confidence of run-off CTA to derive a treat-ment decision was assessed in an interdisciplinary vascular conference using a 2 point scale (sufficient or not sufficient diagnostic confidence) and compared with the image quality eval-uated by two readers in consensus in four different levels (abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment decision was verified in all patients undergoing re-vascularization therapy. Results Diagnostic confidence of run-off CTA to derive a treatment deci-sion was sufficient in all patients with acute and in 97% of patients (215/221) with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image quality was considerably higher in the calf and foot level (acute vs. chronic; calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was superior for patients with chronic (123/133 = 92%) than for patients with acute PAD (64/78 = 82%, P = 0.02). Conclusion Run-off CTA is a reliable imaging modality for primary diag-nostic work-up of patients with acute and chronic PAD

Dual-Energy CT angiography of peripheral arteries in patients with peripheral arterial occlusive disease

In dieser Arbeit werden die Anwendungsmöglichkeiten der Dual-Energy (DE) Computertomographie (CT) für die angiografische Darstellung der Becken- und Beinstrombahn (BB-CTA) bei Patienten mit einer peripheren arteriellen Verschlusskrankheit (PAVK) untersucht. Material und Methoden: In zwei klinischen und einer experimentellen Studie wurde erstens der Zusammenhang zwischen dem Vorliegen von kardiovaskulären Risikofaktoren und der Wahrscheinlichkeit für das Auftreten von die Diagnose einschränkenden starken Gefäßverkalkungen bei PAVK-Patienten untersucht. Zweitens wurde die Effizienz der DE-basierten Nachbearbeitung für die Befundung und Demonstration im Vergleich zu bisherigen manuellen, teils semiautomatischen Nachbearbeitungsmethoden der BB-CTA experimentell und klinisch ermittelt. Ergebnisse: Die BB-CTA zeigt im Vergleich zum Goldstandard der Digitalen Subtraktionsangiographie (DSA) eine vergleichbar gute Gefäßbildgebung der Becken- und Beinarterien bei PAVK-Patienten. Diabetes mellitus und Dialyse sind die stärksten Prädiktoren für das Vorliegen von kompromittierenden Gefäßverkalkungen. Die DE-basierte Nachbearbeitung beschleunigt die Erstellung von DSA-ähnlichen Luminogrammen deutlich, wobei die erstmals mögliche Plaquesubtraktion bisher nur bei guter Kontrastierung in der Becken- und Oberschenkeletage funktioniert. Schlussfolgerung: Die BB-CTA ist eine sehr gute Bildgebungsmodalität der Becken- und Beinstrombahn. Da ihre Aussagekraft bei starken Gefäßverkalkungen insbesondere am Unterschenkel noch eingeschränkt ist, sollten Patienten mit einer hohen Wahrscheinlichkeit für das Vorliegen von kompromittierenden Gefäßverkalkungen, z.B. Diabetiker und Dialysepatienten, andere Bildgebungen erhalten. Die relativ neue Technik der Dual-Energy-BB-CTA zeigt, dass die zusätzliche spektrale Information die Bildrekonstruktion bereits deutlich verbessert aber im Bereich der Plaquesubtraktion noch limitiert ist.This work aims to evaluate the application of Dual-Energy (DE) computed tomography in the angiographic assessment of lower-extremity arteries (Run-off CTA) for patients with peripheral arterial disease (PAOD). Firstly, in a retrospective clinical study Run-off CTA and digital subtraction angiography (DSA), which served as a goldstandard, were compared to assess the relation between cardiovascular risk factors and the probability of severe vessel calcifications which impair the diagnostic image quality. In a second project comprising an experimental and a retrospective clinical study the reliability of the recently developed automatic DE-based postprocessing algorithm for the creation of luminograms from CTA, that are comparable to DSA was investigated and compared to current manual and semi-automatic algorithms Results: Compared to DSA the Run-off CTA is an equivalent imaging modality for the lower- extremity arteries of patients with PAOD as long as no severe vessel calcifications occur. Among the cardiovascular risk factors, diabetes and dialysis are the strongest predictors for the occurrence of severe vessel calcifications. The DE-based postprocessing improves the image quality significantly and reduces the time for the creation of luminograms. However, the further developed automatic DE-based plaque subtraction technique is still limited to high luminal contrast in pelvic and thigh arteries. Conclusion: Run-off CTA is a highly reliable imaging modality for the diagnosis of peripheral arterial disease. Because of still existing limitations in the diagnostic image quality, in particular for the calf arteries with severe vessel calcifications, patients with diabetes or dialysis who are likely to show critical vessel calcifications should be diagnosed using different imaging modalities. The Dual-Energy Run-off CTA as a relatively new method already significantly improves the image reconstruction due to additional spectral information. However, until now, the automatic DE-based plaque subtraction is still limited to the larger vessels with high luminal enhancement

Phantom study for comparison between computed tomography- and C-Arm computed tomography-guided puncture applied by residents in radiology

PURPOSE Comparison of puncture deviation and puncture duration between computed tomography (CT)- and C-arm CT (CACT)-guided puncture performed by residents in training (RiT). METHODS In a cohort of 25 RiTs enrolled in a research training program either CT- or CACT-guided puncture was performed on a phantom. Prior to the experiments, the RiT's level of training, experience playing a musical instrument, video games, and ball sports, and self-assessed manual skills and spatial skills were recorded. Each RiT performed two punctures. The first puncture was performed with a transaxial or single angulated needle path and the second with a single or double angulated needle path. Puncture deviation and puncture duration were compared between the procedures and were correlated with the self-assessments. RESULTS RiTs in both the CT guidance and CACT guidance groups did not differ with respect to radiologic experience (p = 1), angiographic experience (p = 0.415), and number of ultrasound-guided puncture procedures (p = 0.483), CT-guided puncture procedures (p = 0.934), and CACT-guided puncture procedures (p = 0.466). The puncture duration was significantly longer with CT guidance (without navigation tool) than with CACT guidance with navigation software (p < 0.001). There was no significant difference in the puncture duration between the first and second puncture using CT guidance (p = 0.719). However, in the case of CACT, the second puncture was significantly faster (p = 0.006). Puncture deviations were not different between CT-guided and CACT-guided puncture (p = 0.337) and between the first and second puncture of CT-guided and CACT-guided puncture (CT: p = 0.130; CACT: p = 0.391). The self-assessment of manual skills did not correlate with puncture deviation (p = 0.059) and puncture duration (p = 0.158). The self-assessed spatial skills correlated positively with puncture deviation (p = 0.011) but not with puncture duration (p = 0.541). CONCLUSION The RiTs achieved a puncture deviation that was clinically adequate with respect to their level of training and did not differ between CT-guided and CACT-guided puncture. The puncture duration was shorter when using CACT. CACT guidance with navigation software support has a potentially steeper learning curve. Spatial skills might accelerate the learning of image-guided puncture. KEY POINTS · The CT-guided and CACT-guided puncture experience of the RiTs selected as part of the program "Researchers for the Future" of the German Roentgen Society was adequate with respect to the level of training.. · Despite the lower collective experience of the RiTs with CACT-guided puncture with navigation software assistance, the learning curve regarding CACT-guided puncture may be faster compared to the CT-guided puncture technique.. · If the needle path is complex, CACT guidance with navigation software assistance might have an advantage over CT guidance.. CITATION FORMAT · Meine TC, Hinrichs JB, Werncke T et al. Phantom study for comparison between computed tomography- and C-Arm computed tomography-guided puncture applied by residents in radiology. Fortschr Röntgenstr 2022; 194: 272 - 280

Pie chart for distribution of origin of intermittent claudication assessed with run-off CTA.

<p>The chart presents the distribution and incidence of vascular (VASC), musculoskeletal (MSK), and combined (COMB) causes of intermittent claudication. Additionally, the percentage of patients with clinically relevant extravascular incidental findings (crEVIFs) is displayed for each group (+crEVIFs, shaded area). In the vast majority of cases IC is due to vascular pathology (96%). In 31% of the cases coexisting musculoskeletal findings might also explain intermittent claudication. In only 4% of cases was MSK pathology identified as the only underlying cause.</p

Example of a patient with known chronic PAD.

<p>The MIP (30° LAO) on the left shows the patient’s complex vascular situation with iliacofemoral crossover bypass and chronic SFA occlusions. The right side shows the lumbar spine with herniated vertebral disk between the fourth and fifth lumbar vertebrae and consecutive lumbar spinal stenosis (arrow).</p

Distribution of crEVIFs.

<p>Distribution of crEVIFs.</p