Delivery Of Contrast Material Research Articles

CSF - injected contrast medium enhances post-traumatic spinal cord cysts. An experimental study in rats.

Spinal cord injury (SCI) is still one of the most challenging problems in neurosurgical practice. One of the major obstacles to neural regeneration following trauma is the formation of glial scarring and post-traumatic cysts which acts against proper growth of axons through the site of injury. Cerebrospinal fluid (CSF) delivery of bioactive agents into cystic cavities could represent a promising therapeutic strategy. In the present study, we investigated specifically the dynamics of intradural delivery of contrast medium and its relocation into post-traumatic cysts in an experimental model of spinal cord cryoinjury in rats. 32 male Sprague Dawley SPF rats were submitted to injury as previously described. Omnipaque-240 was injected either into the cisterna magna or at the level of the cauda equina. Subsequently, cerebral CT scan examinations were performed in order to check the CSF dynamics of the contrast medium. There was a steady accumulation of contrast medium into post-traumatic cysts as early as five minutes after injection. A dosage of 65 mg of iodine per kilogram ensured an adequate feeling of the cysts at an average of 30 minutes. Our data indicate that intraspinal injection of bioactive agents can easily reach the site of injury and fill post-traumatic cysts. This could represent an interesting potential therapeutic protocol for SCI.

CT pulmonary angiography: optimising acute thoracic imaging by fixed-timing contrast medium delivery with a modified breathing instruction

To compare the thoracic vascular opacification achieved using the standard bolus-tracking protocol (BTP) with a fixed-timing protocol (FTP) with a modified breathing instruction during computed tomography pulmonary angiography (CTPA) examinations. A single-centre review of CTPA examinations performed between July 2018 and January 2019 using the BTP or FTP and weight-based contrast dosing of 20 mg iodine/kg body weight/s for 20 seconds at 100 kV tube potential. Radiodensity (in Hounsfield units) was analysed in the right ventricle, main pulmonary artery (MPA), left atrium, left ventricle, and ascending and descending thoracic aorta (DTA). A p-value of <0.05 was considered significant. Of 782 examinations, 88 BTP and 90 FTP examinations were included. Mean attenuation of the MPA was similar in the FTP (396±106 HU) and BTP (362±119 HU; p=0.06); however, good-quality (≥250 HU) MPA opacification was achieved in more FTP examinations (87/90, 96.7%) compared to the BTP (73/88, 82.9%; p=0.002). Mean attenuation of the DTA was better in the FTP (325±72 HU) than the BTP (228±75 HU; p <0.0001), with good-quality opacification (≥250 HU) in 76/90 (84.4%) FTP examinations compared with 36/88 (40.9%) BTP examinations (p <0.001). The FTP achieves better opacification of the MPA and DTA compared to the BTP.

A Case and Brief Review of Bilious Ascites and Abdominal Compartment Syndrome from Pancreatitis-Induced Post-Roux-En-Y Gastric Remnant Leak

This is a case of a 55-year-old man with Roux-en-Y gastric bypass surgery 15 years prior who presented with acute pancreatitis and developed distributive shock, bacteremia, acute respiratory distress syndrome, anuric acute renal failure, and a distended abdomen with increasing ascitic fluid on imaging. An elevated bladder pressure, lactic acidosis, and anuria raised concern for abdominal compartment syndrome. Paracentesis was done and four liters of bilious ascitic fluid were drained. Intra-abdominal pressure was measured and improved from 27 cmH2O to 13 cmH2O with paracentesis. Mean arterial pressure and urine output also improved. The patient developed recurrent loculated intra-abdominal fluid collections, though ultrasound, CT scans with and without contrast, MRCP, ERCP, upper GI fluoroscopy, and small bowel enteroscopy failed to reveal a source of the bilious output. Ultimately, a gastrostomy tube was placed and delivery of contrast material through the tube revealed active extravasation from the remnant stomach. This case underscores the importance of considering post-surgical leak regardless of how remotely a Roux-en-Y surgery took place, confirms the importance of pursuing early gastrostomy tube placement and contrast administration when post-Roux-en-Y gastric remnant leaks are suspected, and demonstrates the role of paracentesis in critically ill patients with abdominal compartment syndrome.

Comparison of four contrast medium delivery protocols in low-iodine and low-radiation dose CT angiography of the aorta

To evaluate contrast medium delivery protocols for the optimal enhancement profile of the aorta with both a reduced dose of radiation and contrast medium, called double-low computed tomography (CT) angiography (DLCTA). DLCTA was performed with 70 kVp and 200 mg iodine/kg in 205 patients following four protocols, namely slow rate (n=52), short duration (n=52), low concentration (n=50), and combined method (n=51), in comparison with a conventional group (120 kVp, 400 mg iodine/kg, n=51). The quantitative measurement of aortic attenuation, homogeneity, and subjective scores were evaluated. Overall, in the four DLCTA groups, the radiation dose was reduced by 62%, and the iodine dose was reduced by 50%. Among the four DLCTA groups, the signal to noise ratio (SNR) and contrast to noise ratio (CNR) of the thoracic aorta were similar, but a significant difference was noted in the abdominal aorta. The short-duration group had the highest peak enhancement, least homogeneity, and worst subjective scores. Good contrast enhancement and good homogeneity were significantly more frequent in the slow-rate (86.6% and 90.4%, respectively) and low-concentration groups (78% and 96.0%, respectively). Subjective scores exhibited a trend of higher scores in the low-concentration group and lower scores in the slow-rate group (p=0.071). DLCTA with 70 kVp and 200 mg iodine/kg is feasible for whole-aortic CT angiography. The low-concentration protocol is recommended owing to its most consistent optimal aortic enhancement profile. Alternatively, the slow-rate protocol can be considered for patients with limited venous access.

Extra-abdominal dual-energy CT applications: a comprehensive overview

Unlike conventional computed tomography, dual-energy computed tomography is a relatively novel technique that exploits ionizing radiations at different energy levels. The separate radiation sets can be achieved through different technologies, such as dual source, dual layers or rapid switching voltage. Body tissue molecules vary for their specific atomic numbers and electron density, and the interaction with different sets of radiations results in different attenuations, allowing to their final distinction. In particular, iodine recognition and quantification have led to important information about intravenous contrast medium delivery within the body. Over the years, useful post-processing algorithms have also been validated for improving tissue characterization. For instance, contrast resolution improvement and metal artifact reduction can be obtained through virtual monoenergetic images, dose reduction by virtual non-contrast reconstructions and iodine distribution highlighting through iodine overlay maps. Beyond the evaluation of the abdominal organs, dual-energy computed tomography has also been successfully employed in other anatomical districts. Although lung perfusion is one of the most investigated, this evaluation has been extended to narrowly fields of application, such as musculoskeletal, head and neck, vascular and cardiac. The potential pool of information provided by dual-energy technology is already wide and not completely explored, yet. Therefore, its performance continues to raise increasing interest from both radiologists and clinicians.

Review of Clinical Applications for Virtual Monoenergetic Dual-Energy CT.

In this article, the authors discuss the technical background and summarize the current body of literature regarding virtual monoenergetic (VM) images derived from dual-energy CT data, which can be reconstructed between 40 and 200 keV. Substantially improved iodine attenuation at lower kiloelectron volt levels and reduced beam-hardening artifacts at higher kiloelectron volt levels have been demonstrated from all major manufacturers of dual-energy CT units. Improved contrast attenuation with VM imaging at lower kiloelectron volt levels enables better delineation and diagnostic accuracy in the detection of various vascular or oncologic abnormalities. Low-kiloelectron-volt VM imaging may be useful for salvaging CT studies with suboptimal contrast material delivery or providing additional information on the arterial vasculature obtained from venous phase acquisitions. For patients with renal impairment, substantial reductions in the use of iodinated contrast material can be achieved by using lower-energy VM imaging. The authors recommend routine reconstruction of VM images at 50 keV when using dual-energy CT to exploit the increased contrast properties. For reduction of beam-hardening artifacts, VM imaging at 120 keV is useful for the initial assessment.

Assessment of factors that could affect the success of US-guided contrast injection for hip MR arthrography

BackgroundTo retrospectively evaluate the association between possible influencing factors and failed first attempts to inject a contrast agent intra-articularly under ultrasound (US)-guidance for direct magnetic resonance (MR) arthrography of the hip joint. MethodsNinety consecutive patients (38 women and 52 men; mean age, 42 years) undergoing US-guided hip MR arthrography (3 bilaterally) were retrospectively included in this study. The potential influencing factors were sex, age, body mass index (BMI), side of injection, target site, trajectory of the needle, additional use of needle tip rotation, failed first-attempt, and capsule elongation at the site of needle insertion. ResultsFirst-attempt failure was significantly associated with reduced capsule elongation at the target site and no additional use of needle tip rotation (OR 10.708; 95% CI 1.847–62.059; OR 3.518; 95% CI 1.120–11.047). Capsule elongation (sufficient for needle bevel insertion) was significantly larger at the femoral head-neck junction (5.2 ± 1.5 mm) than at the femoral head (2.9 ± 1.3 mm) (p < 0.001). ConclusionLess capsular elongation of the femoral head and no additional use of needle tip rotation to reduce the difficulty in contrast material delivery can increase the first-attempt failure rate in patients undergoing US-guided hip arthrography.

Assessing the Risk of Contrast-Induced Nephropathy Using a Finger Stick Analysis in Recalls from Breast Screening: The CINFIBS Explorative Study.

Purpose To evaluate whether a handheld point-of-care (POC) device is able to predict and discriminate patients at potential risk of contrast-induced nephropathy (CIN) prior to iodine-based contrast media delivery. Methods and Materials Between December 2014 and June 2016, women undergoing contrast-enhanced spectral mammography (CESM) with an iodine-based contrast agent were asked to have their risk of CIN assessed by a dedicated POC device (StatSensor CREAT) and a risk factor questionnaire based on national guidelines. Prior to contrast injection, a venous blood sample was drawn to compare the results of POC with regular laboratory testing. Results A total of 351 patients were included; 344 were finally categorized as low risk patients by blood creatinine evaluation. Seven patients had a eGFR below 60 ml/min/1.73 m2, necessitating additional preparation prior to contrast delivery. The POC device failed to categorize six out of seven patients (86%), leading to (at that stage) unwanted contrast administration. Two patients subsequently developed CIN after 2–5 days, which was self-limiting after 30 days. Conclusion The POC device tested was not able to reliably assess impairment of renal function in our patient cohort undergoing CESM. Consequently, we still consider classic clinical laboratory testing preferable in patients at potential risk for developing CIN.

Influence of different reconstruction parameters in the visualization of intracranial stents using C-arm flat panel CT angiography: experience in an animal model.

C-arm flat panel computed tomography angiography (CA-CTA) is a relatively new imaging modality. Consequently, knowledge about postprocessing parameters and their influence on image quality is still limited, especially for the visualization of implanted microstents. To optimize reconstruction parameters by evaluating the influence of these different parameters for CA-CTA visualization of microstents in an animal model. Eleven microstents were implanted within the left common carotid artery of 11 New Zealand white rabbits. Both CA-CTA, using intra-venous delivery of contrast material, and conventional digital subtraction angiography (DSA) was performed. CA-CTA datasets were reconstructed using three different image characteristics (normal, sharp, smooth). Two experienced neuroradiologists evaluated the image quality and performed measurements of inner and outer stent diameters as well as measurements of the lumen area. Stent deployment was performed successfully in all animals. Inter-observer correlation coefficient for all measurements was high (r = 0.87-0.92). Lumen area and inner stent diameter were significantly smaller in image characteristic "smooth" (P < 0.01) than in "sharp" and "normal". Outer stent diameter was larger in "smooth" than in "sharp" and "normal" (P < 0.01). Stent strut size was significantly wider using image characteristic "smooth". "Sharp" and "normal" compared best to DSA, with "sharp" providing the closest match to DSA measurements, with the trade-off of significantly more noise than in the "normal" reconstructions. The use of different image characteristics in the postprocessing of CA-CTA datasets has an influence on the visualization of implanted stents. Image characteristic "sharp" and "normal" compared best to DSA.

A life cycle assessment of packaging options for contrast media delivery: comparing polymer bottle vs. glass bottle

This paper compares environmental impacts of two packaging options for contrast media offered by GE Healthcare: +PLUSPAK™ polymer bottle and traditional glass bottle. The study includes all relevant life cycle stages from manufacturing to use and final disposal of the bottles and includes evaluation of a variety of end-of-life disposal scenarios. The study was performed in accordance with the international standards ISO 14040/14044, and a third-party critical review was conducted. The functional unit is defined as the packaging of contrast media required to deliver one dose of 96 mL to a patient for an X-ray procedure. Primary data are from GE Healthcare and its suppliers; secondary data are from the ecoinvent database and the literature. A variety of end-of-life disposal scenarios are explored using both cutoff and market-based allocation. Impact assessment includes human health (midpoint) and ecosystems and resources (end point) categories from ReCiPe (H) and cumulative energy demand. Sensitivity analyses include (1) bottle size, (2) secondary packaging, (3) manufacturing electricity, (4) glass recycled content, (5) scrap rate, (6) distribution transport, (7) contrast media, and (8) choice of impact assessment method. Uncertainty analysis is performed to determine how data quality affects the study conclusions. This study indicates that the polymer bottle outperforms the glass bottle in every environmental impact category considered. Bottle components are the most significant contributors, and the vial body has the highest impacts among bottle components for both polymer and glass bottles. The polymer bottle exhibits lower impact in all impact categories considered regardless of the following: end-of-life treatment (using either cutoff or market-based allocation), bottle size, manufacturing electricity grid mix, glass recycled content, scrap rate, contrast media, distribution transport (air vs. ocean), and choice of impact assessment method. Secondary packaging can be a major contributor to impact. The polymer bottle has considerably lower impact compared to the glass bottle for all multi-pack configurations, but the comparison is less clear for single-pack configurations due to significantly higher packaging material used per functional dose, resulting in proportionally higher impacts in all impact categories. The lower impacts of the polymer bottle for this packaging application can be attributed to lower material and manufacturing impacts, lower distribution impacts, and lower end-of-life disposal impacts. The results of this study suggest that using polymer rather than glass bottles provides a means by which to lower environmental impact of contrast media packaging.

Nanodisco balls: control over surface versus core loading of diagnostically active nanocrystals into polymer nanoparticles.

Nanoparticles of complex architectures can have unique properties. Self-assembly of spherical nanocrystals is a high yielding route to such systems. In this study, we report the self-assembly of a polymer and nanocrystals into aggregates, where the location of the nanocrystals can be controlled to be either at the surface or in the core. These nanospheres, when surface decorated with nanocrystals, resemble disco balls, thus the term nanodisco balls. We studied the mechanism of this surface loading phenomenon and found it to be Ca2+ dependent. We also investigated whether excess phospholipids could prevent nanocrystal adherence. We found surface loading to occur with a variety of nanocrystal types including iron oxide nanoparticles, quantum dots, and nanophosphors, as well as sizes (10–30 nm) and shapes. Additionally, surface loading occurred over a range of polymer molecular weights (∼30–3000 kDa) and phospholipid carbon tail length. We also show that nanocrystals remain diagnostically active after loading onto the polymer nanospheres, i.e., providing contrast in the case of magnetic resonance imaging for iron oxide nanoparticles and fluorescence for quantum dots. Last, we demonstrated that a fluorescently labeled protein model drug can be delivered by surface loaded nanospheres. We present a platform for contrast media delivery, with the unusual feature that the payload can be controllably localized to the core or the surface.

Normal Breast Parenchyma: Contrast Enhancement Kinetics at Dynamic MR Mammography—Influence of Anthropometric Measures and Menopausal Status

To study T1 baseline signal intensity (SI) and contrast material enhancement kinetics of normal breast parenchyma by using dynamic contrast-enhanced (DCE) magnetic resonance (MR) mammography and to determine the influence of anthropometric measures and menopausal status on the variability of these features. Institutional review board approval and written informed consent were obtained. Between June 2008 and September 2011, 345 women (age range, 26-81 years; mean age, 51.3 years ± 11.6 [standard deviation]) underwent DCE MR mammography, with T1-weighted three-dimensional MR images (repetition time msec/echo time msec, 8.86/4.51; flip angle, 25°) acquired with a 1.5-T whole-body MR unit before and 1, 2, 3, 4, and 5 minutes after a gadobutrol bolus injection of 0.1 mmol per kilogram of body weight. Regions of interest were traced manually, and T1 SI of parenchyma was recorded. The influence of different predictors of T1 baseline SI and contrast enhancement was studied by using random-effects models. T1 baseline SI varied considerably between women, with a mean of 167.7 ± 49.2 (71.4-424.7 [range]) and 175.9 ± 48.9 (51.8-458.3) in the right and the left breast, respectively (P < .01). T1 baseline SI increased linearly with age (P < .0001) and body weight (P < .0001). After contrast material delivery, relative percentage of enhancement was 8.1%, 13.8%, 18.2%, 22.1%, and 24.6% at 1, 2, 3, 4, and 5 minutes, respectively, but varied considerably between women. Contrast enhancement was 9.3% in the lowest quintile and 47.4% in the highest. Contrast enhancement increased with body weight (P < .01) but decreased in postmenopausal women (P < .01). Women with higher baseline T1 SI tended to have a higher contrast enhancement slope. Anthropometric measures and menopausal status contribute to a large variability in contrast enhancement of normal breast parenchyma. This might influence the interpretation of contrast enhancement kinetics of breast lesions and current strategies for determining contrast medium dose for breast MR imaging.

Robotic-Assisted Angioplasty: Current Status and Future Possibilities

Percutaneous coronary intervention (PCI) has seen steady technological progress over the past 3 decades. Despite improved patient safety and efficacy, modern interventionalists continue to face significant occupational hazards, including radiation exposure, cataracts, and orthopedic injuries. Robotic remote navigation systems have been developed to address risks and procedural challenges associated with conventional PCI. The first in-human experience using a modern robotic system for PCI yielded excellent results, with an overall technical success rate of 97.9%. A larger multicenter prospective registry with this system is currently underway. Robotic PCI technology holds promise to reduce operator radiation exposure and musculoskeletal complaints. Postulated benefits to patients include more accurate lesion length calculations, precise stent placement, and reductions in radiation exposure and contrast-media delivery. The development of novel robotic remote control navigation systems represents the dawn of a new era of interventional cardiology.

Optimization of Contrast Material Delivery for Dual-Energy Computed Tomography Pulmonary Angiography in Patients With Suspected Pulmonary Embolism

To prospectively compare subjective and objective measures of image quality using 4 different contrast material injection protocols in dual-energy computed tomography pulmonary angiography (CTPA) studies of patients with suspected pulmonary embolism. A total of 100 consecutive patients referred for CTPA for the exclusion of pulmonary embolism were randomized into 1 of 4 contrast material injection protocols manipulating iodine concentration and iodine delivery rate (IDR, expressed as grams of iodine per second): Iomeprol 400 at 3 mL/s (IDR = 1.2 gI/s), iomeprol 400 at 4 mL/s (IDR = 1.6 gI/s), iomeprol 300 at 5.4 mL/s (IDR = 1.6 gI/s), or iomeprol 300 at 4 mL/s (IDR = 1.2 gI/s). Total iodine delivery was held constant. Dual-energy CTPA of the lungs were acquired and used to calculate virtual 120 kV CTPA images as well as iodine perfusion maps. Attenuation values in the thoracic vasculature and image quality of virtual 120 kV CTPAs were compared between groups. Iodine perfusion maps were also compared by identifying differences in the extent of beam-hardening artifacts and subjective image quality. Protocols with an IDR of 1.6 gI/s provided the best attenuation profiles. CTPA image quality was greatest in the high concentration, high IDR (1.6 gI/s) protocol (P < 0.05 for all group comparisons) with no differences between the other groups (all P ≥ 0.05). Extent of beam-hardening artifacts and perfusion map image quality was significantly better using the high concentration, high IDR protocol as compared with all groups (P < 0.05 for all comparisons) and significantly worse using the low concentration, low IDR protocol as compared with all groups (all P ≥ 0.05); no difference was found between the high concentration, low IDR protocol and the low concentration, high IDR protocol (P = 0.73 for comparison of beam-hardening artifacts; P = 0.50 for comparison of perfusion map image quality). High iodine concentration and high IDR contrast material delivery protocols provide the best image quality of both CTPA and perfusion map images of the lung through high attenuation in the pulmonary arteries and minimization of beam-hardening artifacts.

Use of expiratory CT pulmonary angiography to reduce inspiration and breath-hold associated artefact: Contrast dynamics and implications for scan protocol

To investigate the effects of scanning in expiration during computed tomography pulmonary angiography (CTPA). One hundred and eighty-one consecutive expiratory CTPA examinations were compared with 145 inspiratory CTPA examinations performed using a standardized protocol through assessment of attenuation seen in the cardiac chambers, pulmonary artery (PA), and ascending aorta. Expiratory scans showed greater attenuation at the pulmonary trunk, right PA, left PA, lobar and segmental PAs (p<0.05). Expiratory scans showed a lower incidence of transient contrast medium interruption (p<0.001) and generalized unsatisfactory PA opacification (p<0.05). Scans with generalized low PA attenuation had lower attenuation in the right ventricle, left heart, and ascending aorta (p<0.001) suggesting that contrast medium delivery or dilution prior to contrast medium entry into the PA is responsible. Expiratory scans showed lower quality scores (p<0.001) for depiction of lung parenchyma. Expiratory scanning could be used as an optimal protocol for dedicated PA imaging. However, it suffers from inferior parenchymal imaging and should probably be reserved for failed inspiratory breath-hold CTPA.

Body CT: Technical Advances for Improving Safety

In this review, we attempt to address many of the issues that are related to ensuring patient benefit in body CT, balancing the use of ionizing radiation and iodinated contrast media. We attempt to not only summarize the literature but also make recommendations relevant to CT protocols, including the technical parameters of both the scanner and the associated contrast media. Although CT is a powerful tool that has transformed the practice of medicine, the benefits are accompanied by important risks. Radiologists must understand these risks and the strategies available to minimize them as well as the risks associated with contrast medium delivery in abdominal CT.

Contrast and Cost Savings by Implementation of a Multidose Bulk IV Contrast Delivery System

In an effort to standardize clinical operations and reduce intravenous (IV) contrast costs, the authors' department switched from 100-mL single-use IV contrast vials to a multidose IV contrast delivery system using iopromide 370. The purpose of this study was to assess IV contrast use, waste, and cost savings resulting from the implementation of this multidose system. A review was conducted of consecutive pulmonary embolism (PE) CT angiography, head and neck (HN) CT angiography, and abdomen/pelvis (AP) CT examinations performed according to standard department protocol 2 weeks before and 2 weeks after the implementation of a multidose IV contrast delivery system. The amount of contrast loaded and injected for each examination was recorded, and total contrast used and wasted were calculated. Volumes of used and wasted contrast were compared before and after implementation using Wilcoxon's rank-sum test. Associated cost savings are reported. There were 32 PE, 27 HN, and 124 AP examinations performed using the 100-mL single-use vial technique and 27 PE, 25 HN, and 175 AP examinations using the multidose technique. Use of the multidose system resulted in average reductions in used contrast volume of 15.9, 35.1, and 11.4 mL, respectively, for PE, HN, and AP examinations (Wilcoxon's P < .0001). For PE and HN examinations, this was due to reduced contrast waste, as these protocols require less than the 100-mL contents of the single-use vial. For AP examinations, savings were due to reduction in contrast volume through the use of higher iodine concentration. Associated cost savings annualize to approximately $31,800 for these 3 examination types alone at the authors' institution. The implementation of a multidose bulk IV contrast material delivery system results in significant contrast and cost savings.

Cardiothoracic CT Angiography: Current Contrast Medium Delivery Strategies

Over the last decade, rapid technologic evolution in CT has resulted in improved spatial and temporal resolution and acquisition speed, enabling cardiothoracic CT angiography to become a viable and effective noninvasive alternative in the diagnostic algorithm. These new technologic advances have imposed new challenges for the optimization of contrast medium delivery and image acquisition strategies. Thorough understanding of contrast medium dynamics is essential for the design of effective acquisition and injection protocols. This article provides an overview of the fundamentals affecting contrast enhancement, emphasizing the modifications to contrast material delivery protocols required to optimize cardiothoracic CT angiography.

Current Contrast Media Delivery Strategies for Cardiac and Pulmonary Multidetector-row Computed Tomography Angiography

Recent advances in multidetector-row computed tomography (MDCT) have led to substantial improvements in coverage area, acquisition speed, and temporal/spatial resolution, which have strengthened the performance of thoracic and cardiac MDCT angiography but have also imposed new challenges for optimization of contrast medium enhancement and scan acquisition strategies. Understanding contrast media dynamics is fundamental for the design of scan acquisition and injection protocols. This article examines the fundamentals of the physiological and contrast delivery factors that determine the quality of contrast enhancement, emphasizing the modifications required in contrast delivery protocols for optimizing cardiothoracic MDCT angiography with modern-era MDCT scanners.

Imaging of the pulmonary arteries

For decades, classical pulmonary digital subtraction angiography (DSA) has served as the gold standard for the direct assessment of the pulmonary vasculature. During the past decade, substantial advances have been achieved in all cross-sectional imaging modalities in terms of spatial and temporal resolution. As a consequence of that, computed tomography angiography (CTA) and magnetic resonance imaging (MRI) are the modalities of choice for the morphological (CTA) and functional (MRI) assessment and will be presented in the context of the technical developments (CT: from single-slice scanners to modern multi-slice equipment, including latest innovations such as 320-slice CT and flash technology; MR: 1.5T vs. 3.0T, parallel imaging, time-resolved MR angiographic secquences, as well as perfusion MR imaging). Dedicated contrast media delivery protocols are a prerequisite for optimal results.