Computed tomography derived anatomical predictors of vascular access complications following transfemoral transcatheter aortic valve implantation: A systematic review.

BACKGROUND: Vascular complications after percutaneous transfemoral transcatheter aortic valve implantation (TAVI) are associated with adverse clinical outcomes and remain a significant challenge. AIMS: The purpose of this review is to synthesize the existing evidence regarding the iliofemoral artery features predictive of vascular complications after TAVI on pre-procedural contrast-enhanced multidetector computed tomography (MDCT). METHODS: A systematic search was performed in Embase and Medline (Pubmed) databases. Studies of patients undergoing transfemoral TAVI with MDCT were included. Studies with only valve-in-valve TAVI, planned surgical intervention and those using fluoroscopic assessment were excluded. Data on study cohort, procedural characteristics and significant predictors of vascular complications were extracted. RESULTS: We identified 23 original studies involving 8697 patients who underwent TAVI between 2006 and 2020. Of all patients, 8514 (97.9%) underwent percutaneous transfemoral-TAVI, of which 8068 (94.8%) had contrast-enhanced MDCT. The incidence of major vascular complications was 6.7 ± 4.1% and minor vascular complications 26.1 ± 7.8%. Significant independent predictors of major and minor complications related to vessel dimensions were common femoral artery depth (>54 mm), sheath-to-iliofemoral artery diameter ratio (>0.91-1.19), sheath-to-femoral artery diameter ratio (>1.03-1.45) and sheath-to-femoral artery area ratio (>1.35). Substantial iliofemoral vessel tortuosity predicted 2-5-fold higher vascular risk. Significant iliofemoral calcification predicted 2-5-fold higher risk. The iliac morphology score was the only hybrid scoring system with predictive value. CONCLUSIONS: Independent iliofemoral predictors of access-site complications in TAVI were related to vessel size, depth, calcification and tortuosity. These should be considered when planning transfemoral TAVI and in the design of future risk prediction models.

Evaluation of pancreatic iodine uptake and related influential factors in multiphase dual-energy CT.

OBJECTIVES: To establish normative values and identify potential factors influencing pancreatic iodine uptake using dual-energy CT (DECT). MATERIALS AND METHODS: This retrospective study included participants without pancreatic diseases undergoing DECT at two institutions with different platforms. Their protocols both included arterial phase (AP), portal venous phase (PP), and equilibrium phase (EP), defined as 35 s-40 s, 60 s-70 s, and 150 s-180 s after injection of contrast agent, respectively. Both iodine concentration (IC) and normalised IC (NIC) were measured. Demographic features, local measurements of the pancreas and visceral fat area (VFA) were considered as potential factors influencing iodine uptake using multivariate linear regression analyses. RESULTS: A total of 562 participants (median age 58 years [interquartile range: 47-67], with 282 men) were evaluated. The mean IC differed significantly between two institutions (all p < 0.001) across three contrast-enhanced phases, while the mean NIC showed no significant differences (all p > 0.05). The mean values of NIC were 0.22 at AP, 0.43 at PP and 0.45 at EP. NICAP was independently affected by VFA (ß = 0.362, p < 0.001), smoking (ß = -0.240, p = 0.001), and type-II diabetes (ß = -0.449, p < 0.001); NICPP by VFA (ß = -0.301, p = 0.017) and smoking (ß = -0.291, p < 0.001); and NICEP by smoking (ß = -0.154, p = 0.10) and alcohol consumption (ß = -0.350, p < 0.001) with statistical power values over 0.81. CONCLUSION: NIC values were consistent across institutions. Abdominal obesity, smoking, alcohol consumption, and diabetes are independent factors influencing pancreatic iodine uptake. CLINICAL RELEVANCE STATEMENT: This study has provided reference normative values, influential factors and effective normalisation methods of pancreatic iodine uptake in multiphase dual-energy CT for future studies in this area as a new biological marker. KEY POINTS: Evaluation of pancreatic iodine uptake measured by dual-energy CT is a promising method for future studies. Abdominal obesity, smoking, alcohol consumption, diabetes, and sex are independent factors influencing pancreatic iodine uptake. Utility of normalised iodine concentration is necessary to ensure the consistency across different institutions.

MDCT evaluation of Dorsal Pancreatic Artery and Intrapancreatic arcade anatomy.

OBJECTIVE: The purpose of the study was to analyze the anatomy and variations in the origin of the dorsal pancreatic artery, greater pancreatic artery and to study the various types of arterial arcades supplying the pancreas on multidetector CT (MDCT). METHODS: A retrospective analysis of 747 MDCT scans was performed in patients who underwent triple phase or dual phase CT abdomen between December 2020 and October 2022. Variations in origin of Dorsal pancreatic artery (DPA), greater pancreatic artery (GPA), uncinate process branch were studied. Intrapancreatic arcade anatomy was classified according to Roman Ramos et al. into 4 types-small arcades (type I), small and large arcades (type II), large arcades (type III) and straight branches (type IV). RESULTS: The DPA was visualized in 65.3% (n = 488) of cases. The most common origin was from the splenic artery in 58.2% (n = 284) cases. The mean calibre of DPA was 2.05 mm (1.0-4.8 mm). The uncinate branch was seen in 21.7% (n = 106) with an average diameter of 1.3 mm. The greater pancreatic artery was seen in 57.3% (n = 428) predominantly seen arising from the splenic artery. The most common arcade anatomy was of Type II in 52.1% (n = 63) cases. CONCLUSION: Pancreatic arterial variations are not very uncommon in daily practice. Knowledge of these variations before pancreatic surgery and endovascular intervention procedure is important for surgeons and interventional radiologist.

Efficacy of larger valve sizing with underfilling in balloon-expandable transcatheter aortic valve replacement.

OBJECTIVES: To investigate the efficacy and safety of larger valve sizing beyond the commercially recommended annular range in transcatheter aortic valve replacement (TAVR) with balloon-expandable transcatheter heart valve (THVs). BACKGROUND: The clinical implications of larger balloon-expandable THV implantation with underfilling are poorly evaluated. METHODS: This retrospective study included 692 consecutive patients who underwent TAVR with SAPIEN3. A total of 271 patients who underwent SAPIEN 3 implantation were analyzed based on three border zones (Zone 1: 300-345 mm2 , 23 vs. 20 mm; Zone 2: 400-430 mm2 , 26 vs. 23 mm; Zone 3: 500-546 mm2 , 29 vs. 26 mm). The primary endpoint was the effective orifice area (EOA) assessed by echocardiography at 1 year, and secondary endpoints were a 30-day mortality rate, procedural complications during TAVR, and a composite of death from any cause and heart failure requiring rehospitalization at 1 year. RESULTS: At 1-year follow-up, the EOA in the larger valve groups was greater than that in the recommended valve group in each zone (Zone 1: 1.45 ± 0.03 vs. 1.06 ± 0.06 cm2 , p < 0.001; Zone 2: 1.83 ± 0.05 vs. 1.41 ± 0.05 cm2 , p < 0.001; Zone 3: 1.93 ± 0.07 vs. 1.69 ± 0.07 cm2 , p = 0.02). No significant difference in the secondary endpoint was observed in any of the zones. CONCLUSIONS: Implantation of the out-of-range larger SAPIEN 3 THVs with underfilling was associated with greater EOA at the 1-year follow-up and feasible in the selected patients.

Management of vertebral compression fractures: the role of dual-energy CT in clinical practice.

PURPOSE: To evaluate the role of dual-energy computed tomography (DECT) in the management of vertebral compression fractures in clinical practice. MATERIALS AND METHODS: This retrospective IRB-approved study included 497 consecutive patients with suspected acute vertebral fractures, imaged either by DECT (group 1) or MRI (group 2) before vertebroplasty. The site, number and type of fractures at imaging findings, and clinical outcome based on any change in pain (DELTA-VAS), before (VAS-pre) and after treatment (VAS-post), were determined and compared. Two radiologists evaluated DECT and MRI images (15 and 5 years of experience, respectively), and inter-observer and intra-observer agreement were calculated using k statistics. RESULTS: Both in the control group (n = 124) and in the group of patients treated by vertebroplasty (n = 373), the clinical outcome was not influenced by the imaging approach adopted, with a DELTA-VAS of 5.45 and 6.42 in the DECT group and 5.12 and 6.65 in the MRI group (p = 0.326; p = 0.44). In the group of treated patients, sex, age, lumbar fractures, multiple fractures, previous fractures, Genant grade, involvement of anterior apex or superior endplates, and increased spinal curvatures were similar (p = ns); however, dorsal fractures were more prevalent in group 1 (p = 0.0197). Before treatment, the mean VAS-pre was 8.74 in group 1 (DECT) and 8.65 in group 2 (MRI) (p = 0.301), whereas after treatment, the mean VAS-post value was 2.32 in group 1 (p = 0.0001), and 2.00 in group 2 (p = 0.0001). The DELTA-VAS was 6.42 in the group of patients imaged using DECT and 6.65 in the group imaged using MRI (p = 0.326). Inter-observer and intra-observer agreement were 0.85 and 0.89 for DECT, and 0.88 and 0.91 for MRI, respectively. CONCLUSION: The outcome of vertebral compression fracture management was no different between the two groups of patients studied.

Partial anomalous pulmonary venous connection: state-of-the-art review with assessment using a multidetector computed tomography angiography.

Pulmonary venous anomalies occur as a result of failure in normal embryological development. These anomalies may present as a spectrum ranging from normal variation to partial anomalous pulmonary venous connection (PAPVC) and total anomalous pulmonary venous connection (TAPVC). Though not rare, PAPVC is an uncommon anomaly in which some of the pulmonary veins abnormally connect and drain into the vascular compartments other than the left atrium (LA); however, the others drain normally into the LA. The clinical presentation and severity of affected patients depend on the morphological heterogeneity of the disease. PAPVC associated with other complex conge-nital cardiac diseases present early and are more severe than isolated PAPVC-associated atrial septal defect only. This radiological review gives a detailed description of PAPVC in terms of morphological variability and associated anomalies along with a discussion of the role of multidetector dual-source computed tomography scan in the diagnostic assessment.

Spontaneous thrombosis of a transcatheter aortic valve replacement-induced aortic root pseudoaneurysm.

Aortic annulus rupture or aortic root perforation is a rare complication of transcatheter aortic valve replacement (TAVR), requiring emergent cardiac surgery and carrying a high intraoperative mortality. Few cases can be managed conservatively, provided a strict clinical follow-up. This study describes the case of a 78-year-old patient with a degenerated bicuspid aortic valve stenosis who presented with a late aortic root perforation following TAVR, which was successfully managed applying a "watchful waiting" approach. Cardiac computed tomography imaging played a pivotal role in the diagnosis and subsequent decision on treatment and clinical follow-up.

Computer-assisted valve in valve in a deteriorated Mosaic valve using a library of bioprostheses.

Valve-in-valve (ViV) procedures have emerged from an off-label procedure to a safe and efficient alternative to redo aortic valve replacement in the treatment of symptomatic structural valve deterioration (SVD). During ViV procedures, optimal placement of the transcatheter heart valve (THV) inside the degenerated bioprosthesis is of paramount importance regarding complications such as device embolization, coronary obstruction, periprosthetic regurgitation, residual gradients, and mitral valve injury, but also for the attainment of optimal hemodynamics. In the case of the Mosaic (Medtronic, Minneapolis, MN) valve, the limited radiopaque landmarks represent a challenge to a reproducible, optimal implantation. Such implantation may require multiple contrast injections and transesophageal echocardiogram (TEE) guidance. We herein describe a computer-assisted ViV procedure inside a deteriorated Mosaic valve, achieving reproducible optimal placement using a preacquired library of bioprostheses 3D models. Our approach suggests an evolving paradigm in ViV procedures, from safe and efficient toward optimal therapy for symptomatic SVD.

Adding Delayed Phase Images to Dual-Phase Contrast-Enhanced CT Increases Sensitivity for Small Pancreatic Ductal Adenocarcinoma.

BACKGROUND. Contrast-enhanced CT performed for pancreatic ductal adeno-carcinoma (PDAC) detection traditionally uses a dual-phase (pancreatic and portal venous) protocol. However, PDAC may exhibit isoattenuation in these phases, hindering detection. OBJECTIVE. The purpose of this study was to assess the impact on diagnostic performance in detection of small PDAC when a delayed phase is added to dual-phase contrast-enhanced CT. METHODS. A database of 571 patients who underwent triple-phase (pancreatic, portal venous, and delayed) contrast-enhanced MDCT between January 2017 and March 2020 for suspected pancreatic tumor was retrospectively reviewed. A total of 97 patients had pathologically confirmed small PDAC (mean size, 22 mm; range, 7-30 mm). Twenty control patients had no pancreatic tumor suspected on CT, on initial MRI and follow-up CT, or on MRI after 12 months or longer. Three radiologists independently reviewed dual-phase and triple-phase images. Two additional radiologists assessed tumors' visual attenuation on each phase, reaching consensus for differences. Performance of dual- and triple-phase images were compared using ROC analysis, McNemar test, and Fisher exact test. RESULTS. AUC was higher (p < .05) for triple-phase than dual-phase images for all observers (observer 1, 0.97 vs 0.94; observer 2, 0.97 vs 0.94; observer 3, 0.97 vs 0.95). Sensitivity was higher (p < .001) for triple-phase than dual-phase images for all observers (observer 1, 74.2% [72/97] vs 59.8% [58/97]; observer 2, 88.7% [86/97] vs 71.1% [69/97]; observer 3, 86.6% [84/97] vs 72.2% [70/97]). Specificity, PPV, and NPV did not differ between image sets for any reader (p ≥ .05). Seventeen tumors showed pancreatic phase visual isoattenuation, of which nine showed isoattenuation and eight hyperattenuation in the delayed phase. Of these 17 tumors, 16 were not detected by any observer on dual-phase images; of these 16, six were detected by at least two observers and five by at least one observer on triple-phase images. Visual attenuation showed excellent interob-server agreement (κ = 0.89-0.96). CONCLUSION. Addition of a delayed phase to pancreatic and portal venous phase CT increases sensitivity for small PDAC without loss of specificity, partly related to delayed phase hyperattenuation of some small PDACs showing pancreatic phase isoattenuation. CLINICAL IMPACT. Addition of a delayed phase may facilitate earlier PDAC detection and thus improved prognosis.

MDCT evaluation of pancreatic contour variations in head, neck, body and tail: surgical and radiological significance.

OBJECTIVE: The purpose of the study was to investigate the incidence of pancreatic contour variations on multidetector CT (MDCT) for abdominal examinations. METHODS: A retrospective analysis of 700 MDCT scans was performed in patients who underwent triple phase CT abdomen between October 2018 and January 2021. After excluding 176 patients, finally total of 524 patients were included in the study. For simplification, we classified the pancreatic contour variations as classified by Ross et al. and Omeri et al. Pancreatic head-neck variations was classified into Type I-anterior, Type II-posterior and Type III-horizontal variety. Pancreatic body-tail variation was divided into Type Ia-anterior projection; Ib-posterior projection and Type IIa-globular, IIb-lobulated, IIc-tapered, and IId-bifid pancreatic tail. RESULTS: The most common type of variation in the head was Type II (n = 112, 21.3%) followed by Type III (n = 37, 7%) and Type I (n = 21, 4%). The most common type of variation in the body of pancreas was Type Ia (n = 33, 6.2%) followed by Type Ib (n = 13, 2.4%). In the tail region of pancreas, the most common variation was Type IIb (n = 21, 4%) followed by Type IIa (n = 19, 3.6%). CONCLUSION: Pancreatic contour variations are not very uncommon in daily practice. Knowledge of these variations is important for surgeons, radiologists and avoids misjudgement of normal pancreatic tissue as tumor or lymph node especially on unenhanced or single phase MDCT.

The role of multidetector computed tomography enterography in the evaluation of localized malignant small intestinal lesions: retrospective radiological and pathological experience.

PURPOSE: Our purpose is to present our experience in using multidetector computed tomography (MDCT) enterography in the evaluation of localized malignant small intestinal lesions with pathological correlation. MATERIAL AND METHODS: We retrospectively evaluated 53 patients of pathologically proven malignant localized small intestinal tumours, who underwent multidetector CT enterography. RESULTS: In this study, the mean age was 51.39 ± 17.4 years. The most commonly affected age group was from 50 to 59 years. The commonest clinical complaint was abdominal pain. The ileum was the most commonly affected anatomical region, showing 25 lesions (47.16%). Radiologically irregular/asymmetric wall thickening was detected in 42 cases(79.24%). Pathologically the most common malignancy was small intestinal adenocarcinoma, followed by carcinoid tumour, lymphoma, and gastrointestinal stromal tumours (GIST). We found that there was a statistically significant association between the pathological lymphadenopathy (p = 0.005) and absent proximal intestinal dilatation (p = 0.01) with intestinal lymphoma. Also, there was a statistically significant association between the extra-intestinal mesenteric fat changes with carcinoid tumours (p = 0.001). Irregular/asymmetric wall thickening was detected in 14 cases of small intestinal adenocarcinoma with a statistically significant association (p = 0.001) while exophytic pathological mass formation was statistically significant associated (p ≤ 0.001) with small intestinal GIST. CONCLUSIONS: Multidetector CT enterography is a non-invasive and accurate method in the evaluation of focal and localized small intestinal malignant lesions. The accurate detection of these lesions depends to some degree on the experience of the radiologist, lesional size, site and pattern of enhancement, as well as adequate intestinal distension.

Preprocedural three-dimensional planning aids in transcatheter ductal stent placement: A single-center experience.

OBJECTIVES: Describe the use of three-dimensional (3D) patent ductus arteriosus (PDA) modeling to better define ductal anatomy to improve preprocedural planning for ductal stent placement. BACKGROUND: Ductal stenting is an alternative to surgical shunting in patients with ductal dependent pulmonary blood flow. Ductal anatomy is often complex with extreme tortuosity and risk of pulmonary artery isolation, thus increasing procedural risks. METHODS: CT angiograms were segmented to produce 3D PDA models. Ductal morphology was characterized with attention to access approach, degree of pulmonary artery offset/risk of isolation and ductal tortuosity. 3D models were retrospectively compared with biplane angiography. RESULTS: 3D modeling was performed in 12 patients with adequate image quality for complete analysis in 11; median (interquartile range) age/weight 17 days (8-20 days) and 3.1 kg (2.4-3.9 kg). The PDA was reverse oriented in nine with average length of 17.2 ± 2.5 mm and high tortuosity (mean tortuosity index 52, range 3-108). From 3D modeling, two patients were excluded from ductal stenting-extreme ductal tortuosity and threatened pulmonary artery discontinuity, respectively. Ductal stenting was successful in the remaining nine with no major procedural complications. 3D modeling predicted a successful access approach based on the aortic orientation of the ductus in all patients (five carotid, two axillary, two femoral). When comparing 2D angiography with 3D models, angiography consistently underestimated ductal length (-3.2 mm ± 1.6 mm) and tortuosity (-14.8 ± 7.2). CONCLUSIONS: 3D modeling prior to ductal stent placement for ductal dependent pulmonary blood flow is useful in procedural planning, specifically for eligibility, access approach, and accurate ductal measurements. Further studies are needed to determine if 3D planning improves procedural outcomes.

TAVR outcome after reclassification of aortic valve stenosis by using a hybrid continuity equation that combines computed tomography and echocardiography data.

BACKGROUND: In the continuity equation, assumption of a round-shaped left ventricular outflow tract (LVOT) leads to underestimation of the true aortic valve area in two-dimensional echocardiography. The current study evaluated whether inclusion of the LVOT area, as measured by computed tomography (CT), reclassifies the degree of aortic stenosis (AS) and assessed the impact on patient outcome after transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: Four hundred and twenty-two patients with indexed aortic valve area index (AVAi) of <0.6 cm2 /m2 , assessed by using the classical continuity equation (mean age: 81.5 ± 6.1 years, 51% female, mean left ventricular ejection fraction: 53.2 ± 13.6%), underwent TAVR and were included. After inclusion of the CT measured LVOT area into the continuity equation, the hybrid AVAi led to a reclassification of 30% (n = 128) of patients from severe to moderate AS. Multivariate predictors for reclassification were male sex, lower mean aortic gradient, and lower annulus/LVOT ratio (all p < .01). Reclassified patients had significantly higher sST2 at baseline and higher NT-proBNP values at baseline and 6 months follow-up compared to non-reclassified patients. Acute kidney injury was experienced more frequently after TAVR by reclassified patients, but no significant mortality difference occurred during 2 years of follow-up. CONCLUSION: The hybrid AVAi reclassifies a significant portion of low-gradient severe AS patients into moderate AS. Reclassified patients showed increased fibrosis and heart failure markers at baseline compared to non-reclassified patients. But reclassification had no significant impact on mortality up to 2 years after TAVR. Routine assessment of hybrid AVAi seems not to improve further risk stratification of TAVR patients.

Technical success and long-term outcomes after anomalous right coronary artery stenting with cardiac computed tomography angiography correlation.

INTRODUCTION: Anomalous origin of coronary arteries has been observed in about 0.35-2.10% of the population. Patients with anomalous right coronary artery (ARCA) may present with significant symptoms, arrhythmias or ACS, and at times sudden death. Traditionally, surgical correction has been the recommended treatment. However, these may be technically challenging, and bypass grafting for such anomalies has the potential for graft failure because of competitive flow. We sought to determine the intermediate and long-term outcomes of drug-eluting stent placement for patients with symptomatic ARCA. We also looked at angiographic findings suggestive of interarterial course as confirmed by subsequent computed tomography (CT) findings. METHODS: Between January 2005 and December 2012, we enrolled 11 patients for elective percutaneous coronary intervention (PCI) of ARCA in a single center, prospective, nonrandomized fashion. Patients were followed up in clinic at 1 week, 3 months, 6 months, and 1 year, and then annually or more frequently if needed. All patients underwent a cardiac CT, as well as functional stress testing when needed to assess for recurrence of disease. RESULTS: All 11 of our patients, who presented with significant symptomatic stenosis with an ARCA, were successfully treated with PCI. Mean follow-up duration was 8.5 years. The only two deaths during follow-up were related to noncardiac causes (sepsis), with a mortality rate of 18.2%. Two patients had a positive functional study and on subsequent coronary angiography, one of them had significant in-stent restenosis (target lesion revascularization of 9.1%) and one distal to the stent (target vessel revascularization 9.1%). We found the observation of a "slit-like lesion" on angiography to have a sensitivity of 100% and specificity of 86% for the diagnosis of interarterial course of the anomalous vessel seen on subsequent CT. CONCLUSIONS: Our study results suggest that PCI of ARCA is an effective and low-risk alternative to surgical correction, with good procedural success and long-term outcomes. It can provide symptomatic relief in such patients and may reduce the risk of sudden death in younger patients, without the inherent risks associated with surgical repair.

Saphenous vein graft aneurysm - Unusual cause of hemoptysis: A case report and review of literature.

Hemoptysis due to saphenous venous graft (SVG) aneurysm is an extremely rare condition and published literature has described the role of conservative management, surgical resection, and covered stent. Here, we report a successful placement of a covered stent for SVG aneurysm in a 56-year-old male who presented with hemoptysis. He was a known diabetic and had undergone a coronary artery bypass grafting 5 years ago. Computed tomography (CT) chest and fiberoptic bronchoscopy performed in another local hospital had revealed blood in the left lingula with spillover into the left lung parenchyma. Hence, he had received empirical anti-tuberculosis medication for 2 months without any improvement. He was referred to our hospital for further management of hemoptysis. Multidetector CT (MDCT) angiography of the chest covering coronaries performed at our hospital revealed SVG aneurysm that was managed with covered stent placement.

Ultra-low-dose CT for extremities in an acute setting: initial experience with 203 subjects.

OBJECTIVE: The purpose of this study was to assess if ultra-low-dose CT is a useful clinical alternative to digital radiographs in the evaluation of acute wrist and ankle fractures. MATERIALS AND METHODS: An ultra-low-dose protocol was designed on a 256-slice multi-detector CT. Patients from the emergency department were evaluated prospectively. After initial digital radiographs, an ultra-low-dose CT was performed. Two readers independently analyzed the images. Also, the radiation dose, examination time, and time to preliminary report was compared between digital radiographs and CT. RESULTS: In 207 extremities, digital radiography and ultra-low-dose CT detected 73 and 109 fractures, respectively (p < 0.001). The odds ratio for fracture detection with ultra-low-dose CT vs. digital radiography was 2.0 (95% CI, 1.4-3.0). CT detected additional fracture-related findings in 33 cases (15.9%) and confirmed or ruled out suspected fractures in 19 cases (9.2%). The mean effective dose was comparable between ultra-low-dose CT and digital radiography (0.59 ± 0.33 µSv, 95% CI 0.47-0.59 vs. 0.53 ± 0.43 µSv, 95% CI 0.54-0.64). The mean combined examination time plus time to preliminary report was shorter for ultra-low-dose CT compared to digital radiography (7.6 ± 2.5 min, 95% CI 7.1-8.1 vs. 9.8 ± 4.7 min, 95% CI 8.8-10.7) (p = 0.002). The recommended treatment changed in 34 (16.4%) extremities. CONCLUSIONS: Ultra-low-dose CT is a useful alternative to digital radiography for imaging the peripheral skeleton in the acute setting as it detects significantly more fractures and provides additional clinically important information, at a comparable radiation dose. It also provides faster combined examination and reporting times.

Comparison of radiation dose and image quality between flat panel computed tomography and multidetector computed tomography in a hybrid CT-angiography suite.

The purpose of this study was to compare, using the same radiation dose and image quality metrics, flat panel computed tomography (FPCT) to multidetector CT (MDCT) in interventional radiology. A single robotic angiography system with FPCT was compared to a single MDCT system, both installed in a hybrid CT-angiography laboratory and both operating under automatic exposure control. Radiation dose was measured on the central axis (Dc ) of a CT dosimetry phantom 30 cm in diameter and 60 cm in length using default protocols for FPCT and MDCT with the imaged length in MDCT matched to the field of view of FPCT. The noise power spectrum (NPS), modulation transfer function (MTF), and z-axis resolution were measured using the same phantom. Iodine contrast to noise ratio (CNR) was also measured. Radiation dose (Dc ) was 41%-69% lower in MDCT compared to FPCT when default protocols and automatic exposure control were used. While spatial resolution could generally be matched with appropriate choice of kernel in MDCT, MTF dropped more quickly at higher spatial frequency for MDCT than FPCT. Image noise was 49%-120% higher for MDCT compared to FPCT for comparable in-plane spatial resolution. Z-axis resolution was slightly better for MDCT than FPCT, while iodine CNR depended on protocol selection. Radiation dose was much lower for MDCT compared to FPCT, but image noise was much higher. Matching image noise in MDCT to FPCT would result in similar radiation doses. Iodine contrast depended on dose modulation settings for MDCT.

Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses.

Duodenal pathology is an infrequent cause of acute abdominal pain for which patients present to the emergency department. Critical pathology on multidetector CT (MDCT) may be overlooked if the radiologist does not carefully evaluate the duodenum as part of the search pattern. Optimal MDCT protocols include intravenous contrast with multiplanar reconstructions (MPRs). A variety of etiologies ranging from infection to malignancy can involve the duodenum, for which interrogation with MPRs is most helpful given the anatomy and complex relationship with surrounding structures. The purpose of this review article is to highlight the importance of CT acquisition with multiplanar reconstructions and review the spectrum of emergent duodenal pathology, with the goal of ensuring accurate and timely diagnosis to best guide patient management.

Differentiation of Clear Cell Renal Cell Carcinoma from other Renal Cell Carcinoma Subtypes and Benign Oncocytoma Using Quantitative MDCT Enhancement Parameters.

Background and objectives: The use of non-invasive techniques to predict the histological type of renal masses can avoid a renal mass biopsy, thus being of great clinical interest. The aim of our study was to assess if quantitative multiphasic multidetector computed tomography (MDCT) enhancement patterns of renal masses (malignant and benign) may be useful to enable lesion differentiation by their enhancement characteristics. Materials and Methods: A total of 154 renal tumors were retrospectively analyzed with a four-phase MDCT protocol. We studied attenuation values using the values within the most avidly enhancing portion of the tumor (2D analysis) and within the whole tumor volume (3D analysis). A region of interest (ROI) was also placed in the adjacent uninvolved renal cortex to calculate the relative tumor enhancement ratio. Results: Significant differences were noted in enhancement and de-enhancement (diminution of attenuation measurements between the postcontrast phases) values by histology. The highest areas under the receiver operating characteristic curves (AUCs) of 0.976 (95% CI: 0.924-0.995) and 0.827 (95% CI: 0.752-0.887), respectively, were demonstrated between clear cell renal cell carcinoma (ccRCC) and papillary RCC (pRCC)/oncocytoma. The 3D analysis allowed the differentiation of ccRCC from chromophobe RCC (chrRCC) with a AUC of 0.643 (95% CI: 0.555-0.724). Wash-out values proved useful only for discrimination between ccRCC and oncocytoma (43.34 vs 64.10, p < 0.001). However, the relative tumor enhancement ratio (corticomedullary (CM) and nephrographic phases) proved useful for discrimination between ccRCC, pRCC, and chrRCC, with the values from the CM phase having higher AUCs of 0.973 (95% CI: 0.929-0.993) and 0.799 (95% CI: 0.721-0.864), respectively. Conclusions: Our observations point out that imaging features may contribute to providing prognostic information helpful in the management strategy of renal masses.

Long-term clinical outcome of persistent left bundle branch block after transfemoral aortic valve implantation.

OBJECTIVE: The impact of persistent left bundle-branch block (pLBBB) on long-term clinical outcome remains to be determined. BACKGROUND: New-onset of pLBBB occurs frequently after transfemoral aortic valve implantation (TAVI). METHODS: Seven hundred and seven consecutive patients who underwent TAVI were analyzed for baseline and procedural characteristics and clinical outcome in an up to 2-year follow-up. Patients were divided into either a group with pLBBB until hospital discharge or a group without LBBB. We performed propensity-score matching and analyzed baseline characteristics, procedural data and clinical outcome of both groups. Patients received balloon-expandable valves in 56.4%, mechanically expandable valves in 37.5%, and self-expandable valves in 6.3%. RESULTS: A new-onset, pLBBB was observed in 47.5% of patients after TAVI. The implantation of a mechanically expandable valve was associated with higher rate of pLBBB (54.2% vs. 20.8%, P < 0.001), whereas implantation of a balloon-expandable valve was associated with lower incidence of pLBBB (39.8% vs. 73.1%, P < 0.001). Deeper ventricular implantation at left-coronary side led to higher rates of pLBBB (7.5 ± 2.5 vs. 6.7 ± 2.6 mm, P < 0.001). The occurrence of pLBBB was associated with higher rates of permanent pacemaker implantation (40.9% vs. 15.9%, P < 0.001). By multivariate analysis, implantation of a mechanically expandable valve (Boston Scientific Lotus valve) was identified as independent predictor of occurrence of pLBBB (odds ratio 4.7, confidence interval 3.2-7.0, P < 0.001). In the 2-year follow-up, there were no significant differences between "pLBBB" and "no LBBB"-groups regarding mortality and rehospitalization due to heart failure. CONCLUSIONS: The occurrence of pLBBB is associated with the choice of valve type and implantation depth and requires significantly higher rates of permanent pacemaker implantations. Importantly, there are no differences in the 2-year follow-up regarding mortality and rehospitalization due to heart failure.