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.

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.

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.

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.

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.

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.

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.

Endoleak detection after endovascular repair of thoracic aortic aneurysm using dual-source dual-energy CT: suitable scanning protocols and potential radiation dose reduction.

OBJECTIVE: The objective of our study was to evaluate the diagnostic performance of dual-source dual-energy CT (DECT) in the detection of endoleaks after thoracic endovascular aortic repair for thoracic aortic aneurysm and to investigate if a double-phase (arterial and dual-energy late delayed phase) or a single-phase (dual-energy late delayed phase) acquisition can replace the standard triphasic protocol. MATERIALS AND METHODS: All DECT examinations performed for evaluation after thoracic endovascular aortic repair during a 30-month period were retrospectively reviewed. An initial single-source unenhanced acquisition was followed by a single-source arterial phase acquisition and a dual-energy 300-second late delayed phase acquisition. "Virtual noncontrast images" were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated the cases during three reading sessions: session A (triphasic protocol: standard unenhanced, arterial phase, and late delayed phase), session B (virtual noncontrast and late delayed phase), and session C (virtual noncontrast, arterial phase, and late delayed phase). The diagnostic accuracies of sessions B and C were calculated using session A as the reference standard. Contrast-to-noise ratios and effective radiation doses were calculated. RESULTS: Forty-eight patients (mean age, 66 years; age range, 19-84 years) underwent 74 triple-phase CT examinations. The single-phase studies (session B) were characterized by 85.7% sensitivity, 100% specificity, 100% negative predictive value (NPV), and 94.6% positive predictive value (PPV). The dual-phase study (session C) revealed 100% sensitivity, 100% specificity, 100% NPV, and 100% PPV. The use of the dual-phase protocol and single-phase protocol resulted in a radiation exposure reduction of 19.5% and 64.1%, respectively. CONCLUSION: Virtual noncontrast and late delayed phase images reconstructed from a single DECT acquisition can replace the standard triphasic protocol in follow-up examinations after thoracic endovascular aortic repair, thereby providing a significant dose reduction.

CT angiography of the upper extremity arterial system: Part 1-Anatomy, technique, and use in trauma patients.

OBJECTIVE: In this article, we focus on the arterial anatomy of the upper extremities, the technical aspects of upper extremity CT angiography (CTA), and CTA use in trauma patients. CONCLUSION: CTA using modern MDCT scanners has evolved into a highly accurate noninvasive diagnostic tool for the evaluation of patients with abnormalities of the upper extremity arterial system.

CT angiography of the upper extremity arterial system: Part 2- Clinical applications beyond trauma patients.

OBJECTIVE: CT angiography using modern MDCT scanners has evolved into a highly accurate noninvasive diagnostic tool for the evaluation of patients with pathologic abnormalities of the upper extremity arterial system. CONCLUSION: Here we focus on the use of this modality in patients with nontraumatic vascular pathologic abnormalities.

Ten frequently asked questions about MRI evaluation of soft-tissue vascular anomalies.

OBJECTIVE: The objective of this article was to address 10 frequently asked questions that radiologists face when planning, performing, and interpreting an MRI study in a patient with a soft-tissue vascular anomaly. CONCLUSION: MRI permits a comprehensive assessment of vascular anomalies. It is important for radiologists to be familiar with the classification and correct nomenclature of vascular anomalies as well as the MRI protocol and distinct imaging findings of the different vascular malformations and tumors.

Noninvasive vascular imaging in abdominal solid organ transplantation.

OBJECTIVE: In this article, we focus on the vascular complications related to liver, pancreas, and kidney transplantation. CONCLUSION: Long term allograft survival of solid organ transplantation depends on early intervention of complications. Noninvasive imaging with ultrasound, CT, and MRI allows accurate diagnosis of complications and aids in treatment planning.

Diagnosis and treatment planning of acute aortic emergencies using a handheld DICOM viewer.

Acute aortic syndromes and traumatic aortic injury are often diagnosed on CT angiography, possibly requiring emergent intervention. Advances in handheld computing have created the possibility of viewing full DICOM datasets from a remote location. We evaluated the ability to diagnose and characterize acute aortic pathologies on CT angiograms of the thorax using an iPhone-based DICOM viewer. This study was performed after Institutional Review Board approval. Fifteen CT angiograms of the thorax in suspected acute aortic syndromes were evaluated by three blinded radiologists on a handheld device using a DICOM viewer. Studies were evaluated for the ability to identify and classify aortic dissection, transection, or intramural hematoma, measure aortic dimensions, and identify mediastinal hematoma, arch variants, and pulmonary pathology. Studies were compared to blinded interpretations on a dedicated PACS workstation. The aortic pathology was correctly identified as aortic transection/pseudoaneurysm (n = 5), type A dissection (n = 2), and type A intramural hematoma (n = 1) by all reviewers, with no false-positive interpretations. This represents a sensitivity and specificity of 100 %. Mediastinal hematoma (n = 6), pneumothorax (five right, three left), and arch vessel involvement (n = 2) were identified in all cases. There was 88.5 % accuracy in identifying arch variants. Measurement of the size of the involved aortic segment was similar on handheld device and PACS workstation; however the adjacent normal aorta was 1.2 ± 1.0 mm larger on the handheld device (p = 0.03). Handheld DICOM viewers may be useful for emergent consultations and triage, and may expedite preprocedure planning to reduce the time interval between diagnostic scan and therapeutic intervention.

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.

Results of external iliac artery reconstruction in avid cyclists.

OBJECTIVE: We report the midterm results of external iliac artery reconstruction in 25 high-performance cyclists. METHODS: Cyclists undergoing arterial reconstruction for symptomatic external iliac arteriopathy at a single institution between October 2004 and August 2010 were identified. With Institutional Review Board approval, data were collected from medical record review and telephone interview. Results were analyzed with χ(2) or independent t-test. RESULTS: Twenty-five patients (31 limbs) underwent operation, which included arterial reconstruction with or without inguinal ligament release. The average patient age at operation was 43.8 ± 5.0 for graft and 35.1 ± 1.9 for patch (P = .08). The average time from competitive cycling until operation was 18.2 ± 5.8 years for graft and 20.0 ± 2.5 for patch repairs (NS). Patients included 14 males and 11 females. There were 23 unilateral and four bilateral arterial reconstructions, including 26 patch angioplasties for localized disease and five interposition grafts for extensive disease; three patients underwent contralateral reconstruction as a separate procedure. Concomitant ipsilateral inguinal ligament release was performed in 25 patients (28 limbs), with contralateral release done in 12 patients (12 limbs). Three patients with isolated ligament release required subsequent arterial intervention. Follow-up averaged 32 months (range, 2-74). Primary patency for all reconstructions was 100%; the four reoperations (five limbs; one bilateral) were for symptom recurrence, two postgraft and two postangioplasty. Three reoperations were for recurrent intimal hyperplasia, one for disease distal to the anastomosis, and one for concomitant atherosclerotic disease. Based on available data, postexercise ankle-brachial indices were improved in 18 of 23 limbs. Seventeen patients completed questions regarding satisfaction: 10 were satisfied or very satisfied (zero graft, 10 patch; P = .25), while four were unsatisfied (three graft, two patch; P = .017, including one patient with both a patch and graft repair). All 20 patients for whom follow-up data were available are still cycling, 10 competitively. Two of the four reoperated patients were unsatisfied; all four are still cycling, one competitively. CONCLUSIONS: External iliac arteriopathy is a disease of prolonged, sustained, and repetitive trauma. Patch angioplasty yields a low rate of reoperation, more satisfied patients, return to competitive activity, and improvement in postexercise ankle-brachial indices. Interposition grafting is associated with slightly older patients, more extensive disease, and less satisfying results. Intimal hyperplasia is the most frequent complication necessitating reoperation. Both the decision to pursue arterial reconstruction and patient expectations must be tempered by the pattern of disease and the potential for unsatisfactory results.

Chronic mesenteric ischaemia: 28-year experience of endovascular treatment.

OBJECTIVE: To report the outcomes associated with endovascular therapy for patients with chronic mesenteric ischemia (CMI). METHODS: A retrospective review of patients who underwent endovascular therapy for CMI between April 1981 and September 2009 at a single institution was performed. Procedural details, mesenteric arteries treated, technical and clinical success rates, outcomes per patient and per vessel were assessed. RESULTS: In 166 patients treatment was attempted using a variety of balloon and stent platforms during the 28-year period. The technical success rate was 97% per patient and 94% per vessel. The technical success rate of stenting (99.4%) was higher than for percutaneous transluminal angioplasty (PTA; 86%; P = 0.0001). Immediate clinical improvement was seen in 146 out of 166 (88.2%). The type of guidewire or device platform, brachial vs. femoral artery access, balloon and/or stent diameters used, and stenosis vs. occlusion had no statistical impact on mortality or the primary patency of any mesenteric artery outcomes. The outcome of the superior mesenteric artery (SMA) with PTA appears to be superior to that of stenting (P = 0.014). CONCLUSION: Technical success rates are improved with the use of stents; however, PTA use in the SMA seems to offer better primary patency rates. KEY POINTS: • Superior mesenteric artery (SMA) stenosis is often responsible for ischaemic symptoms. • Treatment with percutaneous transluminal angioplasty (PTA) seems superior to stenting • Although technical success rates are improved with the use of stents. • Higher mortality in the elderly and those presenting with nausea/vomiting/bloody stools.