Optimizing Identification of Power Injectable Ports on the Scout Images for Multidetector Computed Tomography Procedures.

OBJECTIVE: The objective of this study was to assess the impact of tube voltage and image display on the identification of power ports features on anterior-posterior scout images to inform optimal workflow for multidetector computed tomography (MDCT) examinations. MATERIALS AND METHODS: Four ports, representing variable material composition (titanium/silicone), shapes, and computed tomography (CT) markings, were imaged on an adult anthropomorphic chest phantom using a dual-source MDCT at variable peak tube voltages (80, 100, 120, 150, and Sn150 kVp). Images were reviewed at variable image display setting by 5 blinded readers to assess port features of material composition, shape, and text markings as well as overall preferred image quality. RESULTS: Material composition was correctly identified for all ports by all readers across all kilovoltage-peak settings. The identification by shape was more reliable than CT markers for all but one of the ports. CT marker identification was up to 80% for titanium ports at window level settings optimized for metal (window width, 200; window center, -150) and at a soft tissue setting (window width, 400; window center, 40) for silicone ports. Interreader agreement for best image quality per kilovoltage-peak setting was moderate to substantial for 3 ports (k = 0.5-0.62) but only fair for 1 port (k = 0.27). The highest overall rank for image quality was given unanimously to Sn150 kVp for imaging titanium ports and 100 kVp for silicone ports. CONCLUSIONS: Power port identification on MDCT scout images can be optimized with modification of MDCT scout acquisition and display settings based on the main port material.

Container CT scanner: a solution for modular emergency radiology department during the COVID-19 pandemic.

During the coronavirus disease 2019 (COVID-19) pandemic period, container computed tomography (CT) scanners were developed and used for the first time in China to perform CT examinations for patients with clinically mild to moderate COVID-19 who did not need to be hospitalized for comprehensive treatment, but needed to be isolated in Fangcang shelter hospitals (also known as makeshift hospitals) to receive some supportive treatment. The container CT is a multidetector CT scanner installed within a radiation-protected stand-alone container (a detachable lead shielding room) that is deployed outside the makeshift hospital buildings. The container CT approach provided various medical institutions with the solution not only for rapid CT installation and high adaptability to site environments, but also for significantly minimizing the risk of cross-infection between radiological personnel and patients during CT examination in the pandemic. In this article, we described the typical setup of a container CT and how it worked for chest CT examinations in Wuhan city, the epicenter of COVID-19 outbreak.

CT Fluoroscopy for Image-Guided Procedures: Physician Radiation Dose During Full-Rotation and Partial-Angle CT Scanning.

PURPOSE: To determine physician radiation exposure when using partial-angle computed tomography (CT) fluoroscopy (PACT) vs conventional full-rotation CT and whether there is an optimal tube/detector position at which physician dose is minimized. MATERIALS AND METHODS: Physician radiation dose (entrance air kerma) was measured for full-rotation CT (360°) and PACT (240°) at all tube/detector positions using a human-mimicking phantom placed in a 64-channel multidetector CT. Parameters included 120 kV, 20- and 40-mm collimation, and 100 mA. The mean, standard deviation, and increase/decrease in physician dose compared with a full-rotation scan were reported. RESULTS: Physician radiation exposure during CT fluoroscopy with PACT was highly dependent on the position of the tube/detector during scanning. The lowest PACT physician dose was when the physician was on the detector side (center view angle 116°; -35% decreased dose vs full-angle CT). The highest PACT physician dose was with the physician on the tube side (center view angle 298°; +34% increased dose vs full-angle CT), all doses P <.05 vs full-rotation CT. CONCLUSIONS: Partial-angle CT has the potential to both significantly increase or decrease physician radiation dose during CT fluoroscopy-guided procedures. The detector/tube position has a profound effect on physician dose. The lowest dose during PACT was achieved when the physician was located on the detector side (ie, distant from the tube). This data could be used to optimize CT fluoroscopy parameters to reduce physician radiation exposure for PACT-capable scanners.

A comparative assessment of the performance of a state-of-the art small footprint dedicated cardiovascular CT scanner.

INTRODUCTION: With increasing adoption of CT coronary angiography (CTA) there is increasing demand for cost-effective, small footprint, dedicated cardiac scanners. We compared a state-of-the-art, small footprint dedicated cardiac scanner (DCCT) to a standard multidetector scanner (MDCT). METHODS: The study was a retrospective unblinded single centre study. A total of 800 patients were included, with 400 undergoing a DCCT and MDCT coronary CTA scanning, respectively. Image quality was assessed using a 4-point grading score. Image noise and artifact, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and acceptance rate for CT-derived fractional flow reserve (FFRct) were recorded. RESULTS: Overall image quality was higher in the DCCT group (3.8 ± 0.55 vs 3.6 ± 0.69; p = 0.042). There was no difference in overall image noise (p = 0.131) or artifact (p = 0.295). SNR was superior in the DCCT group (14.2 ± 6.85 vs 11.4 ± 3.32; p < 0.005) as was CNR (12.7 ± 6.77 vs 11.9 ± 3.29; p < 0.005). The heart rate was lower in the DCCT group (56 ± 9.1 vs 59 ± 8.1; p < 0.005). No difference in the dose length product (DLP median 244.53 (IQR 105.6) vs 237.63 (IQR 160.1); p = 0.313) or FFRCT acceptance rate (100 vs 97.7%; p > 0.05) was noted. Independent predictors of excellent quality regardless of scanner type were age (p = 0.011), heart rate <65 bpm (p < 0.005), and body mass index < 35 (p < 0.005). CONCLUSION: A DCCT scanner is capable of image quality similar to modern current generation general purpose CT technology. Such technology appears to be a viable option to serve the increasing demand for CTCA imaging.

Implementation of a new Single-Pass Whole-Body Computed Tomography Protocol: Is it safe, effective and efficient in patients with severe trauma?

PURPOSE: The objective of this study was to evaluate the implementation of a new single-pass whole-body computed tomography Protocol in the management of patients with severe trauma. METHODS: This was a descriptive evaluation of polytrauma patients who underwent whole-body computed tomography. Patients were divided into three groups: 1. Blunt trauma hemodynamically stable 2. Blunt trauma hemodynamically unstable and 3. Penetrating trauma. Demographics, whole-body computed tomography parameters and outcome variables were evaluated. RESULTS: Were included 263 patients. Median injury severity score was 22 (IQR: 16-22). Time between arrival to the emergency department and completing the whole-body computed tomography was under 30 minutes in most patients [Group 1: 28 minutes (IQR: 14-55), Group 2: 29 minutes (IQR: 16-57), and Group 3: 31 minutes (IQR: 13-50; p= 0.96)]. 172 patients (65.4%) underwent non-operative management. The calculated and the real survival rates did not vary among the groups either [Group 1: TRISS 86.4% vs. real survival rate 85% (p= 0.69); Group 2: TRISS 69% vs. real survival rate 74% (p= 0.25); Group 3: TRISS 93% vs. real survival rate 87% (p= 0.07)]. CONCLUSION: This new single-pass whole-body computed tomography protocol was safe, effective and efficient to decide whether the patient with severe trauma requires a surgical intervention independently of the mechanism of injury or the hemodynamic stability of the patient. Its use could also potentially reduce the rate of unnecessary surgical interventions of patients with severe trauma including those with penetrating trauma.

INTRODUCCIÓN: El objetivo de este estudio fue evaluar la implementación de un nuevo protocolo de tomografía computarizada corporal total para el manejo de pacientes con trauma severo. MÉTODOS: Este estudio es una evaluación descriptiva de pacientes que recibieron tomografía computarizada corporal total. Los pacientes fueron divididos en 3 grupos: 1. Trauma cerrado hemodinámicamente estables, 2. Trauma cerrado hemodinámicamente inestables y 3. Trauma penetrante. Se evaluaron las características demográficas, parámetros relacionados con la técnica y los desenlaces de los pacientes. RESULTADOS: Se incluyeron 263 pacientes. La mediana del puntaje de severidad de la lesión fue 22 (RIQ: 16-22). El tiempo entre el ingreso a urgencias y completar la tomografía corporal total fue menor a 30 minutos en la mayoría de pacientes [Grupo 1: 28 minutos (RIQ: 14-55), Grupo 2: 29 minutos (RIQ: 16-57), y Grupo 3: 31 minutos (RIQ: 13-50; p= 0.96). 172 pacientes (65.4%) recibieron manejo no operatorio. Las tasas de supervivencia calculadas y reales no difirieron entre ninguno de los grupos [Grupo 1: TRISS 86.4% vs. Tasa real de supervivencia 85% (p= 0.69); Grupo 2: TRISS 69% vs. Tasa real de supervivencia 74% (p= 0.25); Grupo 3: TRISS 93% vs. Tasa real de supervivencia 87% (p= 0.07)]. CONCLUSIÓN: Este nuevo protocolo de tomografía corporal total de un solo pase fue seguro, efectivo y eficiente para definir si los pacientes con trauma severo requieren o no una intervención quirúrgica. Su uso podría reducir la tasa de intervenciones quirúrgicas innecesarias en estos pacientes incluyendo los que se presentan con trauma penetrante.

Rationale and design of the EPLURIBUS Study (Evidence for a comPrehensive evaLUation of left ventRicle dysfnctIon By a whole-heart coverage cardiac compUted tomography Scanner).

BACKGROUND: Cardiac magnetic resonance (CMR) is the standard of reference for myocardial fibrosis detection by late gadolinium enhancement. Cardiac computed tomography (CCT) is emerging as a promising alternative. The Evidence for a comPrehensive evaLUation of left ventRicle dysfnctIon By a whole-heart coverage cardiac compUted tomography Scanner study will assess the feasibility and diagnostic accuracy of a comprehensive functional and anatomical cardiac evaluation with CCT as compared with CMR and invasive coronary angiography as standard of reference. METHODS: Consecutive patients with a newly diagnosed left ventricle (LV) dysfunction (left ventricular ejection fraction <50%) and a clinical indication to CMR will be screened. Exclusion criteria will be contraindications to contrast agents and impaired renal function. CCT will be performed per protocol within 10 days from CMR. A total of 100 patients will be enrolled within 24 months. We will evaluate with CCT volume and ejection fraction of the LV and right ventricle, presence, extent and pattern of delayed enhancement and cardiac venous system. Moreover, presence and degree of coronary stenoses will be evaluated among patients undergoing invasive coronary angiography in the 6 months following CCT. RESULTS: The primary study endpoints will be: first, to assess the diagnostic performance of CCT vs. CMR to detect the delayed enhancement in a territory-based and patient-based analysis; second, to assess the agreement between CCT and CMR in the discrimination between ischemic vs. nonischemic delayed enhancement patters in a territory-based analysis; third, to assess the correlation between CCT and CMR for LV and right ventricle end-diastolic and end-systolic volumes and ejection fraction measurements. CONCLUSION: The Evidence for a comPrehensive evaLUation of left ventRicle dysfnctIon By a whole-heart coverage cardiac compUted tomography Scanner study will assess the diagnostic performance of CCT using the latest scanner generation for a comprehensive evaluation of patients with new-onset LV dysfunction.

Usefulness of Mobile Computed Tomography in Patients with Coronavirus Disease 2019 Pneumonia: A Case Series.

The coronavirus disease (COVID-19) outbreak has reached global pandemic status as announced by the World Health Organization, which currently recommends reverse transcription polymerase chain reaction (RT-PCR) as the standard diagnostic tool. However, although the RT-PCR test results may be found negative, there are cases that are found positive for COVID-19 pneumonia on computed tomography (CT) scan. CT is also useful in assessing the severity of COVID-19 pneumonia. When clinicians desire a CT scan of a patient with COVID-19 to monitor treatment response, a safe method for patient transport is necessary. To address the engagement of medical resources necessary to transport a patient with COVID-19, our institution has implemented the use of mobile CT. Therefore, we report two cases of COVID-19 pneumonia evaluated by using mobile cone-beam CT. Although mobile cone-beam CT had some limitations regarding its image quality such as scatter noise, motion and streak artifacts, and limited field of view compared with conventional multi-detector CT, both cases had acceptable image quality to establish the diagnosis of COVID-19 pneumonia. We report the usefulness of mobile cone-beam CT in patients with COVID-19 pneumonia.

Improved image quality of temporal bone CT with an ultrahigh-resolution CT scanner: clinical pilot studies.

PURPOSE: Ultrahigh-resolution CT (UHRCT) with slice collimation of 0.25 mm × 160 and matrix size of 1024 × 1024 has become clinically available. We compared the image quality of temporal bone CT (TBCT) between UHRCT and conventional multidetector CT (MDCT). MATERIALS AND METHODS: We retrospectively enrolled 20 patients who underwent TBCT by MDCT (matrix size, 512 × 512) and subsequently by UHRCT (matrix size, 1024 × 1024). Two independent reviewers subjectively graded delineation of normal stapes, oval window, facial nerve canal, incudostapedial joint, and tympanic tegmen. We also quantified image noise in the cerebellar hemisphere. Between MDCT and UHRCT, we compared mean subjective grades using the Wilcoxon signed-rank test and the image noise using paired t test. RESULTS: Grades were significantly higher with UHRCT than with MDCT for all the anatomies (P < 0.001), whereas noise was significantly higher with UHRCT than with MDCT (P = 0.002). CONCLUSION: For TBCT, UHRCT shows better delineation of the fine anatomical structures compared with MDCT.

Implementation of a new Single-Pass Whole-Body Computed Tomography Protocol: Is it safe, effective and efficient in patients with severe trauma? / Implementación de un nuevo protocolo de Tomografía Computarizada Corporal Total de un solo pase: ¿Es seguro, efectivo y eficiente en pacientes con trauma severo?

Abstract Purpose: The objective of this study was to evaluate the implementation of a new single-pass whole-body computed tomography Protocol in the management of patients with severe trauma. Methods: This was a descriptive evaluation of polytrauma patients who underwent whole-body computed tomography. Patients were divided into three groups: 1. Blunt trauma hemodynamically stable 2. Blunt trauma hemodynamically unstable and 3. Penetrating trauma. Demographics, whole-body computed tomography parameters and outcome variables were evaluated. Results: Were included 263 patients. Median injury severity score was 22 (IQR: 16-22). Time between arrival to the emergency department and completing the whole-body computed tomography was under 30 minutes in most patients [Group 1: 28 minutes (IQR: 14-55), Group 2: 29 minutes (IQR: 16-57), and Group 3: 31 minutes (IQR: 13-50; p= 0.96)]. 172 patients (65.4%) underwent non-operative management. The calculated and the real survival rates did not vary among the groups either [Group 1: TRISS 86.4% vs. real survival rate 85% (p= 0.69); Group 2: TRISS 69% vs. real survival rate 74% (p= 0.25); Group 3: TRISS 93% vs. real survival rate 87% (p= 0.07)]. Conclusion: This new single-pass whole-body computed tomography protocol was safe, effective and efficient to decide whether the patient with severe trauma requires a surgical intervention independently of the mechanism of injury or the hemodynamic stability of the patient. Its use could also potentially reduce the rate of unnecessary surgical interventions of patients with severe trauma including those with penetrating trauma.

Resumen Introducción: El objetivo de este estudio fue evaluar la implementación de un nuevo protocolo de tomografía computarizada corporal total para el manejo de pacientes con trauma severo. Métodos: Este estudio es una evaluación descriptiva de pacientes que recibieron tomografía computarizada corporal total. Los pacientes fueron divididos en 3 grupos: 1. Trauma cerrado hemodinámicamente estables, 2. Trauma cerrado hemodinámicamente inestables y 3. Trauma penetrante. Se evaluaron las características demográficas, parámetros relacionados con la técnica y los desenlaces de los pacientes. Resultados: Se incluyeron 263 pacientes. La mediana del puntaje de severidad de la lesión fue 22 (RIQ: 16-22). El tiempo entre el ingreso a urgencias y completar la tomografía corporal total fue menor a 30 minutos en la mayoría de pacientes [Grupo 1: 28 minutos (RIQ: 14-55), Grupo 2: 29 minutos (RIQ: 16-57), y Grupo 3: 31 minutos (RIQ: 13-50; p= 0.96). 172 pacientes (65.4%) recibieron manejo no operatorio. Las tasas de supervivencia calculadas y reales no difirieron entre ninguno de los grupos [Grupo 1: TRISS 86.4% vs. Tasa real de supervivencia 85% (p= 0.69); Grupo 2: TRISS 69% vs. Tasa real de supervivencia 74% (p= 0.25); Grupo 3: TRISS 93% vs. Tasa real de supervivencia 87% (p= 0.07)]. Conclusión: Este nuevo protocolo de tomografía corporal total de un solo pase fue seguro, efectivo y eficiente para definir si los pacientes con trauma severo requieren o no una intervención quirúrgica. Su uso podría reducir la tasa de intervenciones quirúrgicas innecesarias en estos pacientes incluyendo los que se presentan con trauma penetrante.

Interpretability of coronary CT angiography performed with a novel whole-heart coverage high-definition CT scanner in 300 consecutive patients with coronary artery bypass grafts.

AIMS: Coronary CT angiography (CCTA) is an accurate non-invasive tool for the evaluation of coronary artery bypass graft (CABG). However, inability to sustain a long breath-hold, high heart rate (HR) and atrial fibrillation may affect image quality. Moreover, radiation exposure is still a matter of some concern. A scanner combining 0.23-mm spatial resolution, new iterative reconstruction and fast gantry rotation time has been recently introduced in the clinical field. The aims of our study were to evaluate interpretability, radiation exposure and diagnostic accuracy of CCTA performed with the latest generation of cardiac-CT scanners compared to invasive coronary angiography (ICA) in the assessment of bypass grafts, and non-grafted and post-anastomotic native coronary arteries. METHODS AND RESULTS: We prospectively enrolled 300 patients undergoing clinically indicated CCTA with a 16-cm z-axis coverage, 256-detector rows, and 0.28-sec gantry rotation time scanner. Coronary artery and graft interpretability, image quality and effective dose (ED) were assessed in all patients and diagnostic accuracy was evaluated in a subgroup of 100 patients who underwent ICA. Mean HR during the scan was 69.6 ±â€¯10.8. Sinus rhythm was present in 118 patients with HR < 75 bpm and in 112 patients with HR ≥ 75 bpm, while 70 patients had atrial fibrillation. CABG interpretability was 100%. Compared to ICA, CCTA was able to correctly detecting occlusions or significant stenoses of all CABG segments. Overall interpretability of native coronary segments was 95.6%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of coronary arteries were 98.3%, 97.4%, 93.1%, 99.3% and 96.5%, respectively. The diagnostic accuracy in a patient based analysis was 95.2%. Mean ED was 3.14 ±â€¯1.7 mSv. CONCLUSIONS: The novel whole-heart coverage CT scanner allows to evaluating CABG and native coronary arteries with excellent interpretability and low radiation exposure even in the presence of unfavorable heart rhythm.

Accuracy of Pulmonary Nodule Volumetry at Different Exposure Parameters in Low-Dose Computed Tomography: A Phantom Study.

OBJECTIVE: To explore the exposure parameters with minimized radiation dose for accurate pulmonary nodule volumetry using low-dose computed tomography (LDCT). METHODS: An anthropomorphic chest phantom with 11 pulmonary nodules (6 solid nodules and 5 ground-glass opacities) was scanned using 256-slice multidetector computed tomography scanner at various tube voltage and current (combinations of 80, 100 and 120 kV with 10 to 30 mAs). Raw data sets were reconstructed using the hybrid iterative reconstruction method and nodule volume was calculated by a semiautomatic software. The absolute percentage error (APE) of nodule volume relating to the reference acquisition and contrast-to-noise ratio was measured. RESULTS: Nodule characteristic and tube voltage (P < 0.0001) as well as the interaction between nodule characteristic and tube voltage (P = 0.0026) contributed significantly to the mean difference of APE, while tube current did not (P = 0.21). Post hoc analysis revealed no significant difference was found between the APE at 100 kV and 120 kV in both solid nodules (2.3 ± 0.4% vs 1.8 ± 0.6%, P = 0.14) and ground-glass opacities (6.0 ± 0.5% vs 4.9 ± 0.6%, P = 0.11). Exploratory analyses further showed that the APE at 100 kV with 10 mAs did not differ from that at 120 kV with 30 mAs in both solid nodules (2.5 ± 0.5% vs 1.7 ± 0.3%, P = 0.025, corrected P = 0.20) and ground-glass opacities (6.4 ± 0.4% vs 4.8 ± 1.0%, P = 0.0084, corrected P = 0.068). CONCLUSIONS: In our study, the exposure parameters with minimized radiation dose for accurate pulmonary nodule volumetry were found at 100 kV with 10 mAs, and the estimated effect radiation dose was as low as 0.2 mSv, suggesting the feasibility of further reducing radiation dose by decreasing tube voltage and current in LDCT lung screening.

Radiation exposure related to cardiovascular CT examination: comparison between conventional 64-MDCT and third-generation dual-source MDCT.

PURPOSE: To compare radiation exposure associated with daily practice cardiovascular (CV) examinations performed on two different multidetector computed tomography (MDCT) scanners, a conventional 64-MDCT and a third-generation dual-source (DS) MDCT. MATERIALS AND METHODS: In this retrospective study, 1458 patients who underwent CV examinations between January 2017 and August 2018 were enrolled. A single-source 64-MDCT (Lightspeed VCT, GE) scan was performed in 705 patients from January to August 2017 (207 coronary examinations and 498 vascular examinations) and 753 patients underwent third-generation 192 × 2-DSCT (Somatom FORCE, Siemens) scan from January to August 2018 (302 coronary examinations and 451 vascular examinations). Volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), tube voltage (TV) and exposure time (ET), pitch factor (PF) were registered for each patient. Student's t test was used to compare mean values between each corresponding group of MDCT and DSCT. RESULTS: In coronary examinations with DSCT, CTDIvol was 24.4% lower (23.1 mGy vs 30.6 mGy, p < 0.0001) and DLP and ED reductions were 35.6% than with MDCT (465.0 mGy * cm vs 732.3 mGy * cm and 6.5 mSv and 10.3 mSv; vs p < 0.0001). Concerning scan parameters, kVp and ET reductions were 12.7% and 69.4%, respectively (p < 0.0001); PF increase was 73.8% (p < 0.0001). In all vascular studies, DSCT, compared with MDCT, permitted to reduce CTDIvol from 43.5 to 70.6%; DLP and ED reductions were from 50.3 to 73.1%; kVp and ET decreases were from 10.7 to 32.5% and from 26.3 to 68.7%. PF increase was from 16.7 to 58.1% (all differences with p < 0.0001). CONCLUSIONS: In daily practice, CV examinations CTDI, DLP, ED, ET and TV were lower and PF was higher with 192 × 2-DSCT compared to 64-MDCT.

Trends in radiation dose and image quality for pediatric patients with a multidetector CT and a third-generation dual-source dual-energy CT.

AIM: To provide an overview on dose reduction and image quality after the installation of a third-generation dual-source CT (dsCT) in a Pediatric Radiology Department. MATERIALS AND METHODS: We included pediatric patients (< 20 years old) undergoing CT for oncological staging (neck, chest and abdomen) or low-dose chest CT for lung diseases. Each of these two groups were further divided in two age groups (≤ or > 10 years old) including patients scanned in the same period of two consecutive years, in 2017 with a 16-row LightSpeed CT (GE Healthcare) or in 2018 with a Somatom Force dsCT (Siemens Healthineers). Technical parameters such as kVp, mAs, slice thickness, exposure times and dose indicators were retrieved and compared. Image quality was evaluated in consensus by two radiologists on a five-point semiquantitative scale. Nonparametric tests were used. RESULTS: In oncological patients, significantly lower kVp and tube current with better image quality were achieved with the dsCT. Radiation dose (total DLP) was 5-6 times lower with dsCT, thanks also to virtual non-contrast images. In low-dose chest CT, the frequent use of tin filter required higher tube current; a total DLP 3 times lower was achieved with dsCT in patients ≤ 10 years old. The image quality was better with the dsCT in low-dose chest CT protocols. CONCLUSION: The third-generation dsCT provides high-quality images with reduced motion artifacts at lower dose.

Vieussens' arterial ring: a rare coronary variant anatomy.

PURPOSE: We aimed to evaluate Vieussens' arterial ring (VAR) variants by consecutive coronary computed tomography (CT) angiography examinations. METHODS: We retrospectively evaluated the presence of VAR in a total of 3443 consecutive coronary CT angiography examinations performed between November 2010 and January 2015. CT examinations were performed with a 64-row multidetector computed tomography (MDCT) scanner. All CT angiography images were evaluated for the presence and morphologic features of VAR subtypes. VAR variants were classified into four subgroups. RESULTS: Eleven VAR variations (3.19‰) were identified. Type 1A was the most common VAR type (n=8), followed by Type 2 (n=2) and Type 3 (n=1). Type 1B was not detected. CONCLUSION: Although VAR variation is less frequently detected with coronary CT angiography than in previously reported anatomic series, coronary CT angiography is quite effective to reveal VAR subtypes and other relevant cardiocoronary anomalies.

In vitro optimization and comparison of CT angiography versus radial cardiovascular magnetic resonance for the quantification of cross-sectional areas and coronary endothelial function.

BACKGROUND: Our objectives were first to determine the optimal coronary computed tomography angiography (CTA) protocol for the quantification and detection of simulated coronary artery cross-sectional area (CSA) differences in vitro, and secondly to quantitatively compare the performance of the optimized CTA protocol with a previously validated radial coronary cardiovascular magnetic resonance (CMR) technique. METHODS: 256-multidetector CTA and radial coronary CMR were used to obtain images of a custom in vitro resolution phantom simulating a range of physiological responses of coronary arteries to stress. CSAs were automatically quantified and compared with known nominal values to determine the accuracy, precision, signal-to-noise ratio (SNR), and circularity of CSA measurements, as well as the limit of detection (LOD) of CSA differences. Various iodine concentrations, radiation dose levels, tube potentials, and iterative image reconstruction algorithms (ASiR-V) were investigated to determine the optimal CTA protocol. The performance of the optimized CTA protocol was then compared with a radial coronary CMR method previously developed for endothelial function assessment under both static and moving conditions. RESULTS: The iodine concentration, dose level, tube potential, and reconstruction algorithm all had significant effects (all p <  0.001) on the accuracy, precision, LOD, SNR, and circularity of CSA measurements with CTA. The best precision, LOD, SNR, and circularity with CTA were achieved with 6% iodine, 20 mGy, 100 kVp, and 90% ASiR-V. Compared with the optimized CTA protocol under static conditions, radial coronary CMR was less accurate (- 0.91 ± 0.13 mm2 vs. -0.35 ± 0.04 mm2, p <  0.001), but more precise (0.08 ± 0.02 mm2 vs. 0.21 ± 0.02 mm2, p <  0.001), and enabled the detection of significantly smaller CSA differences (0.16 ± 0.06 mm2 vs. 0.52 ± 0.04 mm2; p <  0.001; corresponding to CSA percentage differences of 2.3 ± 0.8% vs. 7.4 ± 0.6% for a 3-mm baseline diameter). The same results held true under moving conditions as CSA measurements with CMR were less affected by motion. CONCLUSIONS: Radial coronary CMR was more precise and outperformed CTA for the specific task of detecting small CSA differences in vitro, and was able to reliably identify CSA changes an order of magnitude smaller than those reported for healthy physiological vasomotor responses of proximal coronary arteries. However, CTA yielded more accurate CSA measurements, which may prove useful in other clinical scenarios, such as coronary artery stenosis assessment.

[Acute abdominal trauma]. / Traumatisches akutes Abdomen.

BACKGROUND: In patients with multiple trauma, abdominal involvement is a particularly relevant injury pattern. Depending on the intensity and manner of injury, heterogeneous but often typical organ manifestations result. Knowledge of these injury patterns is essential for targeted diagnostics and treatment. OBJECTIVE: This review provides a presentation of typical forms of abdominal injury with appropriate radiological techniques and where applicable treatment. MATERIAL AND METHODS: Experiences and case examples from a supraregional trauma center are presented and discussed with the results of a Medline literature search and relevant parts of the german S3 guidelines on polytrauma. RESULTS: Traumatic abdominal injuries are subdivided into blunt and penetrating injuries. Among these groups, blunt trauma with splenic injury being most frequent followed by liver and kidney involvement. In penetrating abdominal injuries hollow visceral organs are most frequently affected. For diagnosis, ultrasound and with escalating injury severity, multidetector computed tomography (MDCT) are the most important methods. For years there has been an ongoing trend towards conservative management and interventional hemorrhage control. This is driven by improvements in imaging that enable a more precise classification and indications for subsequent treatment. CONCLUSION: Progress in radiology has led to an increasingly more important role for radiology in the management of traumatic abdominal injury. Therefore, it is crucial for the radiologist to gain interdisciplinary knowledge of the relevant trauma mechanisms and injury patterns of the severely injured patient in order to provide a treatment process that provides the optimal outcome.

Submillisievert CT angiography for carotid arteries using wide array CT scanner and latest iterative reconstruction algorithm in comparison with previous generations technologies: Feasibility and diagnostic accuracy.

OBJECTIVES: To assess evaluability and diagnostic accuracy of a low dose CT angiography (CTA) protocol for carotid arteries using latest Iterative Reconstruction (IR) algorithm in comparison with standard 100 kVp protocol using previous generation CT and IR. MATERIALS AND METHODS: 105 patients, referred for CTA of the carotid arteries were prospectively enrolled in our study and underwent CTA with 80 kVp and latest IR algorithm (group 1). Data were retrospectively compared with 100 consecutive patients with similar examination indications that had previously undergone CTA of carotid arteries with a standard 100 kVp protocol and a first generation IR algorithm (group 2). Image quality was evaluated with a 4-point Likert-scale. For each exam CT number, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) at level of common carotid artery (CCA), internal carotid artery (ICA) and at level of Circle of Willis and Effective Dose (ED) were evaluated. 62 Group 1 patients underwent a clinically indicated DSA and results were compared with CTA. RESULTS: No exams reported as not diagnostic. The overall mean CT number value of all arterial segments was above 450 HU in both groups. Significant lower noise, and higher SNR and CNR values were found in group 1 in comparison with group 2 despite the use of 80 kVp. In 62-group 1 patients studied by DSA, CTA showed in a segment-based analysis a sensitivity, negative predictive value and accuracy of 100%, 100% and 99% respectively. Mean ED in group 1 was 0.54 ±â€¯0.1 mSv with a dose reduction up to 86%. CONCLUSIONS: CTA for carotid arteries using latest IR algorithm allows to perform exams with submillisievert radiation exposure maintaining good image quality, overall evaluability and diagnostic accuracy.

Comparison of patient dose from routine multi-phase and dynamic liver perfusion CT studies taking into account the effect of iodinated contrast administration.

OBJECTIVES: To accurately determine and compare patient radiation burden from routine multi-phase CT (MPCT) and dynamic CT liver perfusion (CTLP) studies taking into account the effect of iodine uptake of exposed tissues/organs. MATERIALS AND METHODS: 40 consecutive MPCT of upper abdomen and 40 consecutive CTLP studies performed on a modern CT scanner were retrospectively studied. Iodine uptake of radiosensitive tissues at the time of acquisition was calculated through the difference of tissues' CT numbers between NECT and CECT images. Monte Carlo simulation and mathematical anthropomorphic phantoms were employed to derive patient-size-specific organ dose data from each scan involved taking into account the effect of iodinated contrast uptake on absorbed dose. Effective dose estimates were derived for routine multiphase CT and CTLP by summing up the contribution of NECT and CECT scans involved. RESULTS: The mean underestimation error in organ doses from CECT exposures if iodine uptake is not encountered was found to be 2.2%-38.9%. The effective dose to an average-size patient from routine 3-phase CT, 4-phase CT and CTLP studies was found to be 20.6, 27.7 and 25.8 mSv, respectively. Effective dose from CTLP was found lower than 4-phase CT of upper abdomen irrespective of patient body size. Compared to 3-phase CT, the radiation burden from CTLP was found to be higher for average size-patients but again lower for overweight patients. CONCLUSIONS: Modern CT technology allows CTLP studies at comparable or even lower patient radiation burden compared to routine multi-phase liver CT imaging.

The Utility of Virtual Bronchoscopy Using a Computed Tomography Workstation for Conducting Conventional Bronchoscopy: A Retrospective Analysis of Clinical Practice.

BACKGROUND: Recent clinical trials demonstrated the benefits of several guided-bronchoscopy technologies for the diagnosis of peripheral pulmonary lesions (PPLs). However, introduction of these technologies is expensive. Therefore, in clinical practice, these are unavailable in many hospitals. In contrast, virtual bronchoscopy (VB) using the computed tomography (CT) workstation can be made available immediately without additional cost as many hospitals already have the CT scan facility. However, the effectiveness of VB alone remains to be shown. OBJECTIVES: The aim of this study was to investigate the effect of VB using the CT workstation in hospitals performing conventional bronchoscopy. METHODS: Results from consecutive patients who underwent bronchoscopy for small PPLs (major diameter ≤30 mm) were retrospectively reviewed. Sixty-nine patients who underwent bronchoscopy without VB from April 2014 to March 2015 and 56 patients who underwent bronchoscopy with VB from April 2015 to December 2015 were assigned to non-VB and VB groups, respectively. We compared the two groups and analyzed the factors affecting the diagnostic yield. RESULTS: The VB group had a significantly higher diagnostic yield than the non-VB group (57.1 vs. 33.3%; p = 0.008). In the multivariate analysis, VB was identified as a significant factor affecting the diagnostic yield (odds ratio: 3.30, p = 0.011). CONCLUSIONS: In the conventional bronchoscopy settings, VB using the CT workstation is efficient for the diagnosis of PPLs when other guided-bronchoscopy techniques are unavailable.