The enigma of fine mobile structures on the aortic surface in a patient undergoing transcatheter aortic valve replacement: a case report.

Background: The surface of the aorta generally does not show motion unless mobile atheroma, thrombi, vegetations, or intimal flaps are present. We previously described unusual mobile filamentous structures in the carotid artery. Here, we describe similar findings in the aorta and their possible cause. Case summary: An 88-year-old female with progressive exertional dyspnoea and severe aortic stenosis had a successful transcatheter aortic valve replacement (TAVR). A filamentous structure was noted on the focused pre-operative 2D transoesophageal echocardiography in the proximal descending aorta and post-TAVR as long strand-like structures attached to the thickened intimal wall with a planar component on 3D imaging. These findings were not associated with symptoms or clinical sequelae on short- and long-term follow-up. Discussion: The mobile structures that we describe are atypical for atheroma, thrombi, vegetations, and dissections in terms of their form and clinical presentation. 2D imaging showed that the filaments had focal thickening and emerged from the aortic surface. These findings suggest a relationship with the intima, perhaps from atherogenesis or injury with disruption or lifting of the intimal surface. No clinical sequelae were detected that may also relate to their position in the descending aorta and not the arch.

Good Long-Term Outcome Following Liver Transplant in a Patient With Common Variable Immunodeficiency Syndrome Despite Multiple Infections and Recurrent Nodular Regenerative Hyperplasia.

Common variable immunodeficiency can be associated with various hepatic conditions, the most common being nodular regenerative hyperplasia. Multiple cases of liver transplant in adults with common variable immunodeficiency have been reported. Here, we report a 51-year-old man with common variable immunodeficiency and noncirrhotic portal hypertension due to nodular regenerative hyperplasia who underwent liver transplant. The patient received tacrolimus/steroid immunosuppression and remained rejection free; however, he developed cytomegalovirus infection, disseminated nocardiosis, Pseudomonas pneumonia, and Clostridioides difficile- associated colitis. All infections were successfully managed. The graft was well functioning after 18 months; however, alkaline phosphatase remained elevated and a liver biopsy showed evidence of recurrent nodular regenerative hyperplasia. The patient was started on a steroid taper, which led to normalization of the alkaline phosphatase. Two years later, a repeat biopsy confirmed recurrent nodular regenerative hyperplasia. Immunosuppression was kept low, and intravenous immunoglobulin infusions were continued. More than 10 years later, the patient is alive with a functioning graft. This case emphasizes that intensified prophylaxis for infections and less intense immunosuppression may be strategies to enable long-term survival in liver transplant recipients with common variable immunodeficiency and nodular regenerative hyperplasia relapse despite recently reported poor outcomes in this patient population.

Review of Imaging With Focus on New Techniques in Aortic Dissection.

The imaging evaluation of a patient with aortic dissection can be undoubtedly complex, requiring that the interpreting physician understands the classification systems and vocabulary used. This can be made all the more challenging by advances in medical imaging that reshape the understanding of aortic dissection. The purpose of this paper is to provide a review of recent advances in the imaging modalities, and select modality-specific technologies, commonly used to study aortic dissection, including computed tomography, magnetic resonance imaging, and ultrasound. This is followed by an overview of imaging findings, including the classification, initial evaluation, and follow up, of aortic dissection.

Fibromuscular dysplasia: A comprehensive review on evaluation and management and role for multidisciplinary comprehensive care and patient input model.

Fibromuscular dysplasia is a nonatherosclerotic, under-recognized disorder primarily seen in middle-aged women. It can lead to several complications, such as hypertension, headaches, dissections, aneurysms, myocardial infarctions, and cerebrovascular accidents, to name a few. This article provides a comprehensive review of current literature on epidemiology, etiology, diagnosis, treatment, and long-term surveillance and fibromuscular dysplasia management. In addition, it renders the role of education and prevention for patients living with this condition and family screening. Lastly, it emphasizes the importance of a comprehensive multidisciplinary care model and patient input, given the complexity of this disease and its systemic presence and protean manifestations.

Coronary Computed Tomography Angiography Demonstrates a High Burden of Coronary Artery Disease Despite Low-Risk Nuclear Studies in Pre-Liver Transplant Evaluation.

We investigated the presence and severity of coronary artery disease (CAD) in orthotopic liver transplantation (OLT) candidates using coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA) as compared with the prevalence of normal and abnormal single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 140 prospective OLT candidates without known CAD underwent coronary artery calcium (CAC) scans with (n = 77) or without CCTA and coronary computed tomography angiography-derived fractional flow reserve (FFRCT ; n = 57) using a dual-source computed tomography (CT) and were followed for 2.6 ± 1.4 years. Coronary plaque was quantified using the segment-involvement score (SIS) and segment stenosis score (SSS). The mean age was 59 ± 6 years, and 65.0% of patients were male. Mean Agatston CACS was 367 ± 653, and 15.0% of patients had CACSs of 0; 83.6% received a SPECT MPI, of which 95.7% were interpreted as normal/probably normal. By CCTA, 9.1% had obstructive CAD (≥70% stenosis), 67.5% had nonobstructive CAD, and 23.4% had no CAD. Nonobstructive CAD was diffuse with mean SIS 3.0 ± 2.9 and SSS 4.5 ± 5.4. Only 14 patients had high risk-findings (severe 3v CAD, n = 4, CACS >1000 n = 10) that prompted X-ray angiography in 3 patients who had undergone CCTA, resulting in revascularization of a high-risk obstruction in 1 patient who had a normal SPECT study. Patients with end-stage liver disease have a high prevalence of nonobstructive CAD by CCTA, which is undiagnosed by SPECT MPI, potentially underestimating cardiovascular risk. Deferring X-ray angiography unless high-risk CCTA findings are present is a potential strategy for avoiding unnecessary X-ray angiography.

Preprocedural Imaging Evaluation of Pulmonary Valve Replacement After Repair of Tetralogy of Fallot: What the Radiologist Needs to Know.

Tetrallogy of Fallot (TOF) is the most frequent form of cyanotic congenital heart disease. Despite advances in surgical and medical treatment, mortality remains high. Residual dysfunction of the pulmonary valve (PV) after correction of right ventricular outflow tract obstruction is an important cause of morbidity, leading to irreversible right ventricular dysfunction, arrhythmias, heart failure and occasionally, death. The strategies for PVR have evolved over the last decades, and the timing of the intervention remains the foundation of the decision-making process. Symptoms of heart failure are unreliable indicators for optimal timing of repair. Imaging plays an essential role in the assessment of PV integrity and dysfunction. The identification of the best timing for PVR requires a multimodality approach. Transthoracic echocardiography is the most commonly used imaging modality for the initial assessment and follow-up of TOF patients, although its utility has technical limitations, especially in adults. Cardiac computed tomography and magnetic resonance imaging are now routinely used for preoperative and postoperative evaluation of these patients, and provide highly valuable information about the anatomy and pathophysiology. Imaging evidence of disease progression is now part of the major guidelines to define the best timing for reintervention. The purpose of this article is to review the pathophysiology after TOF repair, identify the main imaging anatomic and physiologic features, describe the indications for PVR and recognize the role of imaging in the assessment of these patients to define the appropriate timing of PVR.

Non-coronary abnormalities of the left heart: CT angiography findings.

Cardiac computed tomography (CT) is most commonly performed for the evaluation of the coronary arteries; however, non-coronary cardiac pathologies are frequently detected on these scans. In cases where magnetic resonance imaging cannot be used, cardiac CT can serve as the first-line imaging modality to evaluate many non-coronary cardiac pathologies. In this article, we discuss congenital non-coronary abnormalities of the left heart and their cardiac CT imaging features.

The natural history of penetrating ulcers of the iliac arteries.

OBJECTIVE: The natural history of penetrating ulcers of the iliac arteries (PUIA) has not been previously described. The potential for degeneration into pseudoanerysm and rupture are feared complications. It is hypothesized that PUIA, similar to their thoracic aortic counterparts, signal impending vascular catastrophe. METHODS: A search of computed tomography (CT) angiography reports for the words, "penetrating ulcer" was performed. Patients with PUIA who underwent CT imaging from October 2010 to August 2011 were identified. Their clinical course was followed through December 2014. If patients with PUIA had additional vascular pathology that necessitated intervention, it was performed. A prospective and retrospective review of the imaging was performed when possible. Associated iliac diameter and ulcer dimensions were measured for patients with repeat imaging (n = 22). Demographic characteristics were compared for patients who were identified as having penetrating ulcers of the abdominal aorta. Mann-Whitney U, Fisher exact, and Pearson correlation coefficient tests were performed for statistical analysis. RESULTS: The calculated incidence of PUIA for patients who underwent CT imaging was 0.3%. The age at the time of diagnosis was 70.7 ± 10.0 years and the cohort included 28 male patients (82.3%). Median clinical and imaging follow-up was 42.0 (range, 1-82) months and 40.5 (range, 1-77) months. Most patients had a history of hypertension (82.4%), hyperlipidemia (76.5%), and tobacco use (70.6%). Twenty-one patients (61.8%) had concomitant aneurysms not necessarily associated with the PUIA. Although no PUIA rupture occurred, the population was sick because seven patients (20.6%) were deceased at the study end. Only one individual presented with symptoms that could possibly be attributed to their PUIA. Repeat imaging was performed for 22 patients (64.7%). The calculated median iliac artery diameter growth rate through the PUIA was 0.1 (range, 0-4.1) mm/y. CONCLUSIONS: PUIA are generally slow-growing and are found incidentally. Most patients with PUIA were in their eighth decade with a history of hypertension and tobacco use. Patients with PUIA frequently have concurrent aortic aneurysm disease that requires intervention. The mortality for this population was high, but was not caused by rupture of a PUIA. Diameter changes noted in the PUIA during follow-up did not suggest ulcer treatment would improve survival.

Effectiveness of integrating delayed computed tomography angiography imaging for left atrial appendage thrombus exclusion into the care of patients undergoing ablation of atrial fibrillation.

BACKGROUND: Computed tomography angiography (CTA) can identify and rule out left atrial appendage (LAA) thrombus when delayed imaging is also performed. OBJECTIVE: In patients referred for CTA to evaluate pulmonary vein anatomy before the ablation of atrial fibrillation (AF) or left atrial flutter (LAFL), we sought to determine the effectiveness of a novel clinical protocol for integrating results of CTA delayed LAA imaging into preprocedure care. METHODS: After making delayed imaging of the LAA part of our routine preablation CTA protocol, we integrated early reporting of preablation CTA LAA imaging results into clinical practice as part of a formal protocol in June 2013. We then analyzed the effectiveness of this protocol by evaluating 320 AF/LAFL ablation patients with CTA imaging during the time period 2012-2014. RESULTS: In CTA patients with delayed LAA imaging, the sensitivity and negative predictive values for LAA thrombus using intracardiac echocardiography or transesophageal echocardiography (TEE) as the reference standard were both 100%. Intracardiac echocardiography during ablation confirmed the absence of thrombus in patients with negative CTA or negative TEE results. No patients with either negative CTA results or equivocal CTA results combined with negative TEE results had strokes or transient ischemic attacks. Overall, the need for TEE procedures decreased from 57.5% to 24.0% during the 3-year period because of the CTA protocol. CONCLUSION: Clinical integration of CTA delayed LAA imaging into the care of patients having catheter ablation of AF or LAFL is feasible, safe, and effective. Such a protocol could be used broadly to improve patient care.

The History of Incidentally Discovered Penetrating Aortic Ulcers of the Abdominal Aorta.

BACKGROUND: The management of incidentally discovered penetrating ulcers of the abdominal aorta (PUAA) is not well described. METHODS: A search of computed tomography (CT) angiography imaging reports for the words "penetrating ulcer" was performed from October 2010 to August 2011. Patients with a PUAA were identified, and their clinical course was followed through December 2014 (n = 53). No specific intervention for the ulcers was sought unless additional aortic pathology necessitated intervention. Prospective and retrospective review of imaging was performed by dedicated vascular radiologists. Aortic diameters and ulcer dimensions were measured for patients with repeat imaging. Mann-Whitney U, Fisher's exact, and Pearson correlation coefficient tests were performed for statistical analysis. RESULTS: The calculated incidence of PUAA for patients undergoing CT imaging was 0.48%. Age at diagnosis was 71.6 ± 10.5 years in a population that included 35 (66.0%) males. Repeat imaging was performed for 29 (54.7%) patients. Median clinical and imaging follow-up was 36 (1-127) months and 34 (1-89) months. A history of hypertension (92.5%), hyperlipidemia (77.4%), and tobacco use (81.8%) was common. Twenty-seven (50.9%) had concomitant aneurysms not necessarily associated with PUAA. No aortic aneurysm or PUAA rupture occurred, but the population was sick with 19 patients (35.8%) deceased at the end of the study. Median aortic diameter growth rate through the PUAA was 0.5 (0-11.4) mm/year. No difference in mortality or aortic pathology was detected in patients with aortic growth rates >1 mm/year compared with <1 mm/year (P = 0.21 and P = 0.71, respectively). CONCLUSIONS: Patients with PUAA in general are elderly with multiple comorbidities. A large percentage of patients have concurrent, separate, aortic pathology, most frequently aortic aneurysms. Small changes in the appearance of the PUAA were frequent but did not equate with abdominal aortic catastrophe. Long-term mortality for this population was high, but the ulcer growth during follow-up did not suggest PUAA treatment would improve survival.

Development of bilateral coronary artery aneurysms in a child with Noonan syndrome.

Noonan syndrome is a constellation of congenital malformations including heart defects, facial anomalies and short stature. The cardiovascular defects are variable and extensive, with the most common being pulmonary stenosis and hypertrophic cardiomyopathy. Coronary artery anomalies have only been reported in a few cases. We report a child with Noonan syndrome status post pulmonary stenosis and atrial septal defect repair, who developed bilateral coronary artery aneurysms. The aneurysms were diagnosed with both cardiac magnetic resonance imaging and coronary computed tomography angiography. There had been no evidence of them on a cardiac MR exam 5 years previously.

Complex aortic arch anomaly: Right aortic arch with aberrant left subclavian artery, fenestrated proximal right and duplicated proximal left vertebral arteries-CT angiography findings and review of the literature.

Congenital aortic arch and vertebral artery anomalies are a relatively rare finding discovered on imaging either incidentally or for evaluation of entities like dysphagia or subclavian steal. Right aortic arch is an uncommon anatomical anomaly that occurs in less than 0.1% of the population, and in half of these cases the left subclavian artery is also aberrant.(1) Unilateral vertebral artery (VA) duplication is rare with an observed prevalence of 0.72% in cadavers.(2) Fenestration of the VA is more common than duplication, with a prevalence of approximately 0.23%-1.95%.(3,4) We describe the case of a 25-year-old female who was found to have a right aortic arch with aberrant left subclavian artery, duplicated left vertebral artery and a fenestrated right vertebral artery on CT angiography performed for evaluation of dysphagia. This combination of findings has not been reported before, to the best of our knowledge. We review the embryologic mechanism for the development of the normal aortic arch, right aortic arch, vertebral artery duplication and vertebral artery fenestration. The incidence of these entities, resultant symptoms and clinical implications are also reviewed. The increased associated incidence of aneurysm formation, dissection, arteriovenous malformations and thromboembolic events with fenestration is also discussed.

Computed tomography angiography and magnetic resonance angiography imaging of the mesenteric vasculature.

Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are highly accurate cross-sectional vascular imaging modalities that have almost completely replaced diagnostic catheter angiography for the evaluation of the mesenteric vasculature. CTA is the technique of choice when evaluating patients with suspected mesenteric ischemia; it permits to differentiate between occlusive and nonocclusive etiologies, to evaluate indirect signs of bowel ischemia, and in some instances, to provide alternative diagnoses. MRA has the advantage of not using ionizing radiation and iodinated contrast agents and can be appropriate in the nonacute setting. Both CTA and MRA are suitable for the assessment of patients with suspected chronic mesenteric ischemia, allowing to evaluate the degree of atherosclerotic steno-occlusive disease and the existence of collateral circulation, as well as other nonatherosclerotic vascular pathologies such as fibromuscular dysplasia and median arcuate ligament syndrome. CTA provides excellent depiction of visceral aneurysms and has an important role to plan therapy for both occlusive and aneurysmal diseases and in the follow-up of patients after open or endovascular mesenteric revascularization procedures. This article provides an introduction to the CTA and MRA imaging protocol to study the mesenteric vasculature, the imaging findings in patients presenting with acute and chronic mesenteric ischemia and visceral aneurysms, and the value of these imaging techniques for therapy planning and follow-up.

Noncontrast peripheral MRA with spiral echo train imaging.

PURPOSE: To develop a spin echo train sequence with spiral readout gradients with improved artery-vein contrast for noncontrast angiography. THEORY: Venous T2 becomes shorter as the echo spacing is increased in echo train sequences, improving contrast. Spiral acquisitions, due to their data collection efficiency, facilitate long echo spacings without increasing scan times. METHODS: Bloch equation simulations were performed to determine optimal sequence parameters, and the sequence was applied in five volunteers. In two volunteers, the sequence was performed with a range of echo times and echo spacings to compare with the theoretical contrast behavior. A Cartesian version of the sequence was used to compare contrast appearance with the spiral sequence. Additionally, spiral parallel imaging was optionally used to improve image resolution. RESULTS: In vivo, artery-vein contrast properties followed the general shape predicted by simulations, and good results were obtained in all stations. Compared with a Cartesian implementation, the spiral sequence had superior artery-vein contrast, better spatial resolution (1.2 mm(2) versus 1.5 mm(2) ), and was acquired in less time (1.4 min versus 7.5 min). CONCLUSION: The spiral spin echo train sequence can be used for flow-independent angiography to generate three-dimensional angiograms of the periphery quickly and without the use of contrast agents.

Glomuvenous malformation: magnetic resonance imaging findings.

We report a case of a glomuvenous malformation involving the dorsal aspect of the right hand and distal forearm in an 11-year-old boy. He had a history of multiple vascular anomalies since birth and presented with increasing right hand pain. MRI played an important role in characterizing and determining the extent of the lesion. In particular, dynamic time-resolved contrast-enhanced MR angiography precisely defined its vascularity. The diagnosis was made histopathologically after partial resection of the lesion. Glomuvenous malformation is a rare developmental hamartoma that originates from the glomus body. Clinically they usually resemble a venous malformation but they are a different entity. In the appropriate clinical setting this rare condition must be included in the differential diagnosis of a vascular malformation, especially when subtle arterial enhancement, early venous shunting and progressive filling of dilated venous spaces are depicted on MRA.

Pulmonary toxicity in a rabbit model of stereotactic lung radiation therapy: efficacy of a radioprotector.

This study aimed to assess the efficacy of the radioprotector amifostine in limiting radiation toxicity in a rabbit model of lung stereotactic body radiation therapy (SBRT) by correlating contrast-enhanced magnetic resonance angiography (ce-MRA), computed tomography (CT), and helium-3 (He-3) magnetic resonance imaging (MRI) with histopathology. Multiple MRI techniques were tested to obtain complementing physiologic information. Thirteen rabbits received SBRT to the right lower lobe of the lung. Specifically, 4 received 3 × 11 Gray (Gy), 6 received 3 × 11 Gy and 50 mg/kg of amifostine pre-SRBT, and 3 received 3 × 7, 3 × 9, or 3 × 13 Gy. Imaging was performed at baseline and 4, 8, 12, and 16 weeks post-SBRT. Ce-MRA perfusion difference between lungs in the irradiated group at 16 weeks post-treatment was statistically significant (P = .04) whereas the difference in the irradiated + amifostine group was not (P = .30). Histologically observed low red blood cell (RBC) count and CT hypodensity suggests changes were primarily related to perfusion; however, structural changes, such as increased alveolar size, were also present. No changes in He-3 MRI lung ventilation were observed in either group. Although radiation-induced injury detected in rabbits as CT hypodensity contrasted with increased density observed in humans/rodents, the changes in ce-MRA and CT were still significantly reduced after the addition of amifostine to SBRT. Use of CT and selected MRI techniques helped to pinpoint primary physiologic changes.

Imaging follow-up of endovascular repair of type B aortic dissection with dual-source, dual-energy CT and late delayed-phase scans.

PURPOSE: To evaluate the diagnostic performance of dual-energy (DE) computed tomography (CT) after thoracic endovascular aortic repair (TEVAR) of type B dissection, and to investigate the value of late delayed (LD) acquisition in endoleak detection and false lumen patency assessment. MATERIALS AND METHODS: Twenty-four patients with TEVAR for type B dissection underwent 53 tripe-phase CT examinations. Single-source unenhanced acquisition was followed by single-source arterial-phase and DE LD phase (300-s delay) imaging. Virtual noncontrast images were generated from DE acquisition. Two blinded radiologists retrospectively evaluated the cases in three reading sessions: session A (triphasic protocol), session B (virtual noncontrast and arterial phase), and session C (virtual noncontrast and arterial and LD phases). Endoleak detection accuracy during sessions B and C compared with session A (reference standard) was investigated. False lumen patency was assessed. Effective radiation dose was calculated. RESULTS: Session A revealed 37 endoleaks in 30 of 53 studies (56.6%). Session B revealed 31 of the 37 endoleaks, with one false-positive case, 83.8% sensitivity, 95.8% specificity, 79.3% negative predictive value, and 96.9% positive predictive value. Session C correctly depicted all 37 endoleaks, with one false-positive case, 100% sensitivity, 95.8% specificity, 100% negative predictive value, and 97.4% positive predictive value. Underestimation of false lumen patency was found in session B (P = .013). Virtual noncontrast imaging resulted in 17% radiation exposure reduction. CONCLUSIONS: Virtual noncontrast imaging can replace standard unenhanced images in follow-up after TEVAR of type B dissection, thus reducing radiation dose. Delayed-phase imaging is valuable in low-flow endoleaks detection and false lumen patency assessment.

Refocused turbo spin-echo for noncontrast peripheral MR angiography.

PURPOSE: To develop and assess a three-dimensional refocused turbo spin-echo (rTSE) sequence for generating peripheral angiograms. This sequence combines the rapid T2 -weighting of TSE and the better flow performance of the fully-refocused gradients of balanced steady state free precession (bSSFP), along with bSSFP-style phase alternation of refocusing radiofrequency (RF) pulses. MATERIALS AND METHODS: The signal behavior generated by such a sequence was explored through Bloch equation simulations. The rTSE and TSE sequences were both used to generate peripheral angiograms in nine normal volunteers. The signal to noise ratio, contrast resolution, and vessel sharpness of the resulting images were used as bases for comparison. Additionally, the rTSE sequence was applied in four patients with peripheral artery disease to preliminarily assess its efficacy in a clinical setting through quality scoring by two experienced radiologists. RESULTS: The rTSE's RF phase alternation approach out-performs a simple balanced-gradient CPMG (Carr-Purcell-Meiboom-Gill) -style TSE sequence in the presence of B0 and B1 inhomogeneities. In volunteers, the rTSE sequence yielded better arterial-venous contrast (0.378 ± 0.145 versus 0.155 ± 0.202; P < 0.01) and increased vessel sharpness (0.340 ± 0.034 versus 0.263 ± 0.034; P < 0.005) over TSE images. Stenoses visible in conventional angiographic images in patients were successfully imaged with the rTSE sequence; however, image quality scores in patients were lower than in volunteers (1.2 ± 0.38 versus 3.0 ± 1.0; P < 0.05). CONCLUSION: The rTSE sequence generates nonsubtractive, flow-independent, peripheral MR angiograms with better arterial-venous contrast and vessel sharpness in normal volunteers than a conventional TSE sequence.