High-pitch versus conventional cardiovascular CT in patients being assessed for transcatheter aortic valve implantation: A real-world appraisal

Objective High-pitch protocols are increasingly used in cardiovascular CT assessment for transcatheter aortic valve implantation (TAVI), but the impact on diagnostic image quality is not known. Methods We reviewed 95 consecutive TAVI studies: 44 (46%) high-pitch and 51 (54%) standard-pitch. Single high-pitch scans were performed regardless of heart rate. For standard-pitch acquisitions, a separate CT-aortogram and CT-coronary angiogram were performed with prospective gating, unless heart rate was ≥70 beats/min, when retrospective gating was used. The aortic root and coronary arteries were assessed for artefact (significant artefact=1; artefact not limiting diagnosis=2; no artefact=3). Aortic scans were considered diagnostic if the score was > 1; the coronaries, if all three epicardial arteries scored > 1. Results There was no significant difference in diagnostic image quality for either the aorta (artefact-free high-pitch: 31 (73%) scans vs standard-pitch: 40 (79%), p=0.340) or the coronary tree as a whole (10 (23%) vs 15 (29%), p=0.493). However, proximal coronary arteries were less well visualised using high-pitch acquisitions (16 (36%) vs 30 (59%), p=0.04). The median (IQR) radiation dose was significantly lower in the high-pitch cohort (dose-length product: 347 (318-476) vs 1227 (1150-1474) mGy cm, respectively, p < 0.001), and the protocol required almost half the amount of contrast. Conclusions The high-pitch protocol significantly reduces radiation and contrast doses and is non-inferior to standard-pitch acquisitions for aortic assessment. For aortic root assessment, the high-pitch protocol is recommended. However, if coronary assessment is critical, this should be followed by a conventional standard-pitch, low-dose, prospectively gated CT-coronary angiogram if the high-pitch scan is non-diagnostic

Screening for proximal coronary artery anomalies with 3-dimensional MR coronary angiography

Under 35 years of age, 14% of sudden cardiac death in athletes is caused by a coronary artery anomaly (CAA). Free-breathing 3-dimensional magnetic resonance coronary angiography (3D-MRCA) has the potential to screen for CAA in athletes and non-athletes as an addition to a clinical cardiac MRI protocol. A 360 healthy men and women (207 athletes and 153 non-athletes) aged 18–60 years (mean age 31 ± 11 years, 37% women) underwent standard cardiac MRI with an additional 3D-MRCA within a maximum of 10 min scan time. The 3D-MRCA was screened for CAA. A 335 (93%) subjects had a technically satisfactory 3D-MRCA of which 4 (1%) showed a malignant variant of the right coronary artery (RCA) origin running between the aorta and the pulmonary trunk. Additional findings included three subjects with ventral rotation of the RCA with kinking and possible proximal stenosis, one person with additional stenosis and six persons with proximal myocardial bridging of the left anterior descending coronary artery. Coronary CT-angiography (CTA) was offered to persons with CAA (the CAA was confirmed in three, while one person declined CTA) and stenosis (the ventral rotation of the RCA was confirmed in two but without stenosis, while two people declined CTA). Overall 3D MRCA quality was better in athletes due to lower heart rates resulting in longer end-diastolic resting periods. This also enabled faster scan sequences. A 3D-MRCA can be used as part of the standard cardiac MRI protocol to screen young competitive athletes and non-athletes for anomalous proximal coronary arteries

Unrequested Findings on Cardiac Computed Tomography: Looking Beyond the Heart

Objectives: To determine the prevalence of clinically relevant unrequested extra-cardiac imaging findings on cardiac Computed Tomography (CT) and explanatory factors thereof. Methods: A systematic review of studies drawn from online electronic databases followed by meta-analysis with metaregression was performed. The prevalence of clinically relevant unrequested findings and potentially explanatory variables were extracted (proportion of smokers, mean age of patients, use of full FOV, proportion of men, years since publication). Results: Nineteen radiological studies comprising 12922 patients met the inclusion criteria. The pooled prevalence of clinically relevant unrequested findings was 13 % (95 % confidence interval 9–18, range: 3–39%). The large differences in prevalence observed were not explained by the predefined (potentially explanatory) variables. Conclusions: Clinically relevant extra-cardiac findings are common in patients undergoing routine cardiac CT, and their prevalence differs substantially between studies. These differences may be due to unreported factors such as different definitions of clinical relevance and differences between populations. We present suggestions for basic reporting whic

Linear and Branched Glyco-Lipopeptide Vaccines Follow Distinct Cross-Presentation Pathways and Generate Different Magnitudes of Antitumor Immunity

Glyco-lipopeptides, a form of lipid-tailed glyco-peptide, are currently under intense investigation as B- and T-cell based vaccine immunotherapy for many cancers. However, the cellular and molecular mechanisms of glyco-lipopeptides (GLPs) immunogenicity and the position of the lipid moiety on immunogenicity and protective efficacy of GLPs remain to be determined.We have constructed two structural analogues of HER-2 glyco-lipopeptide (HER-GLP) by synthesizing a chimeric peptide made of one universal CD4(+) epitope (PADRE) and one HER-2 CD8(+) T-cell epitope (HER(420-429)). The C-terminal end of the resulting CD4-CD8 chimeric peptide was coupled to a tumor carbohydrate B-cell epitope, based on a regioselectively addressable functionalized templates (RAFT), made of four alpha-GalNAc molecules. The resulting HER glyco-peptide (HER-GP) was then linked to a palmitic acid moiety, attached either at the N-terminal end (linear HER-GLP-1) or in the middle between the CD4+ and CD8+ T cell epitopes (branched HER-GLP-2). We have investigated the uptake, processing and cross-presentation pathways of the two HER-GLP vaccine constructs, and assessed whether the position of linkage of the lipid moiety would affect the B- and T-cell immunogenicity and protective efficacy. Immunization of mice revealed that the linear HER-GLP-1 induced a stronger and longer lasting HER(420-429)-specific IFN-gamma producing CD8(+) T cell response, while the branched HER-GLP-2 induced a stronger tumor-specific IgG response. The linear HER-GLP-1 was taken up easily by dendritic cells (DCs), induced stronger DCs maturation and produced a potent TLR- 2-dependent T-cell activation. The linear and branched HER-GLP molecules appeared to follow two different cross-presentation pathways. While regression of established tumors was induced by both linear HER-GLP-1 and branched HER-GLP-2, the inhibition of tumor growth was significantly higher in HER-GLP-1 immunized mice (p<0.005).These findings have important implications for the development of effective GLP based immunotherapeutic strategies against cancers

Breast cancer: Follow-up with MRI after therapy

Breast cancer is the most frequent malignancy in women worldwide. The incidence and mortality rates of the disease have increased the past few years, especially in richer countries that have adopted the mammographic screening control. Mastectomy and breast conserving therapy with radiation therapy and/or chemotherapy consist the current therapeutic approach for breast cancer. Follow-up of patients with breast cancer is an issue of great importance in order to estimate the presence of residual tumor in the site of lumpectomy, estimate the presence of recurrence and also assess the outcome of neoadjuvant chemotherapy. Magnetic resonance imaging (MRI) has been introduced the past few decades as a modality for breast imaging. MRI has been established as an accurate method for the follow-up of patients treated for breast cancer

A Novel Experimental Animal Model of Arterial Stenosis Based on Endovascular Radiofrequency Energy Application

Purpose: To develop a new rabbit model of arterial stenosis using endovascular radiofrequency (RF) energy. Materials and Methods: Ten rabbits were used for multiple endovascular RF applications to the aorta and left common carotid artery through the Habib (TM)(TM) VesCoag (TM)(TM) catheter. Angiography and color Doppler ultrasound were used to assess vessel patency immediately following the procedure and six weeks later. One rabbit was sacrificed following the procedure for histopathologic analysis of the vessel wall. Two rabbits died of aortic and carotid rupture, respectively, immediately after the procedure. The remaining seven rabbits were sacrificed after six-week follow-up for histopathological analysis. Results: Optimal RF generator settings to induce significant arterial stenosis (> 50%%) without complications were standardized at 24--26 watts (W) for 1.5 min for the aorta and 6 W for 1 min for the common carotid artery. The six-week follow-up showed permanent results in all surviving rabbits. Histopathology revealed intima and medial smooth muscle layer necrosis. Conclusion: We have developed a novel rabbit model of arterial stenosis using endovascular RF energy. Our model is fast, safe, inexpensive, and reproducible. It would be useful for experimental investigations and new therapeutic devices

Anatomy and Complications Following Laparoscopic Sleeve Gastrectomy: Radiological Evaluation and Imaging Pitfalls

To evaluate the post-operative gastric anatomy depicted by upper gastrointestinal gastrografin swallow studies (UGI) and report radiological work-up and management of complications following laparoscopic sleeve gastrectomy (LSG). The study included 85 consecutive patients who underwent LSG for the treatment of morbid obesity. In all patients, a UGI was routinely performed on POD 3 to exclude early complications. In patients with suspected complications, further radiological evaluation with computed tomography (CT) was performed. The anatomy of the gastric remnant depicted by UGI was retrospectively evaluated in all patients. The patterns of the gastric remnant identified were the tubular (65.9%), the superior pouch (25.9%), and the inferior pouch pattern (8.2%). Three patients had small superior pouches that resembled leaks, and the diagnosis was based on clinical symptoms. Post-operative complications were observed in 12.9% and included leaks (3.5%), hemorrhages (3.5%), strictures (2.3%), pulmonary embolism (1.2%), trocar site hernia (1.2%), and hematoma of the rectus abdominal muscle (1.2%). No mortality was noted. Post-operative radiological evaluation by UGI and CT is important for diagnosis and management of complications following LSG. Familiarity with the anatomy of the gastric remnant at UGI is essential for correct image interpretation