Venous air embolism in CT coronary angiography.

Introduction: Venous air embolization (VAE) from IV lines is a risk with IV contrast administration. The incidence of VAE ranges from 7% to 23%. While life-threatening VAE is rare, there is the potential risk of serious cerebrovascular events from paradoxical systemic air embolization (SAE) in patients with congenital intracardiac shunts.

Non-invasive CT-derived fractional flow reserve and static rest and stress CT myocardial perfusion imaging for detection of haemodynamically significant coronary stenosis.

Computed tomography derived fractional flow reserve (FFR) and computed tomography stress myocardial perfusion imaging (CTP) are techniques to assess haemodynamic significance of coronary stenosis. To compare the diagnostic performance of FFR and static rest/stress CTP in detecting fractional flow reserve (FFR) defined haemodynamically-significant stenosis (FFR ≤ 0.8).

Noninvasive CT-Derived FFR Based on Structural and Fluid Analysis: A Comparison With Invasive FFR for Detection of Functionally Significant Stenosis.

Objectives: This study describes the feasibility and accuracy of a novel computed tomography (CT) fractional flow reserve (FFR) technique based on alternative boundary conditions.

Background: Techniques used to compute FFR based on images acquired from coronary computed tomography angiography (CTA) are described. Boundary conditions were typically determined by allometric scaling laws and assumptions regarding microvascular resistance.

Rest and stress transluminal attenuation gradient and contrast opacification difference for detection of hemodynamically significant stenoses in patients with suspected coronary artery disease.

This study evaluated the feasibility of stress 320 detector CT coronary angiography (CTA) derived transluminal attenuation gradient (TAG320) and contrast opacification (CO) difference to detect hemodynamically significant stenoses as determined by invasive fractional flow reserve (FFR ≤ 0.80). Twenty-seven patients, including 51 vessels on rest CTA were studied.

Dynamic four-dimensional computed tomography (4D CT) imaging for re-entry risk assessment in re-do sternotomy - first experience.

Background: Repeat cardiac surgeries are well known to have higher rates of complications, one of the important reasons being injuries associated with re-do sternotomy. Routine imaging with CT can help to minimise this risk by pre-operatively assessing the anatomical relation between the sternum and the underlying cardiovascular structures, but is limited by its inability to determine the presence and severity of functional tethering and adhesions between these structures. However, with the evolution of wide area detector MD CT scanners, it is possible to assess the presence of tethering using the dynamic four-dimensional CT (4D CT) imaging technique.

Evaluation of the role of lung volume and airway size and shape in supine-predominant obstructive sleep apnoea patients.

Background And Objective: This study aimed to evaluate the involvement of airway cross-sectional area and shape, and functional residual capacity (FRC), in the genesis of obstructive sleep apnoea (OSA) in patients with supine-predominant OSA.

Methods: Three groups were recruited: (i) supine OSA, defined as a supine apnoea-hyponoea index (AHI) at least twice that of the non-supine AHI; (ii) rapid eye movement (REM) OSA, defined as REM AHI at least twice the non-REM AHI and also selected to have supine AHI less than twice that of the non-supine AHI (i.e.

Dynamic 320-slice CT larynx for detection and management of idiopathic bilateral vocal cord paralysis.

Idiopathic bilateral vocal cord paralysis (VCP) is a rare and difficult condition often undiagnosed and frequently confused with asthma and other respiratory conditions. Accurate diagnosis is crucial since 80% of cases patients require surgical intervention, such as tracheostomy or laser surgery, to relieve symptoms. The "gold standard" for diagnosing VCP has been laryngoscopy.

Superior CT coronary angiography image quality at lower radiation exposure with second generation 320-detector row CT in patients with elevated heart rate: a comparison with first generation 320-detector row CT.

Background: This study aims to compare the image quality of second generation versus first generation 320-computed tomography coronary angiography (CTCA) in patients with heart rate ≥65 bpm as it has not been specifically reported.

Methods: Consecutive patients who underwent CTCA using second-generation-320-detector-row-CT were prospectively enrolled. A total of 50 patients with elevated (≥65 bpm) heart rate and 50 patients with controlled (<65 bpm) heart rate were included.

Dynamic four-dimensional computed tomography for preoperative assessment of lung cancer invasion into adjacent structures†.

Objectives: The 320-slice computed tomography (CT) provides three-dimensional and dynamic imaging resulting in the ability to assess motion analysis between two adjacent structures (the fourth dimension). Differential movements between two adjacent structures would indicate that there is no fixation between the two structures.

Methods: Eight patients with non-small-cell lung cancers located adjacent to vital structures (e.

Pre-procedural combined coronary angiography and stress myocardial perfusion imaging using 320-detector CT in unprotected left main and ostial left anterior descending artery intervention.

Pre-procedural anatomic and functional coronary assessment plays a crucial role in selection of patients suitable for unprotected left main percutaneous coronary intervention. Combined coronary computed tomography angiography and adenosine stress computed tomography myocardial perfusion imaging is a non-invasive technique which may provide this information. This is the first report describing its use to assist patient selection and procedural planning prior to elective left main and ostial left anterior descending artery coronary intervention.

Comparison of diagnostic accuracy of combined assessment using adenosine stress computed tomography perfusion + computed tomography angiography with transluminal attenuation gradient + computed tomography angiography against invasive fractional flow reserve.

Objectives: The goal of this study was to compare the diagnostic accuracy of combined computed tomography perfusion (CTP) + computed tomography angiography (CTA), transluminal attenuation gradient by 320-detector row computed tomography (TAG320) + CTA, and CTP + TAG320 + CTA (multidetector computed tomography-integrated protocol [MDCT-IP]) assessment in predicting significant fractional flow reserve (FFR).

Background: CTA has limited specificity for predicting functionally significant stenoses. Novel CT techniques, including adenosine stress CTP and TAG320, may improve the diagnostic accuracy of CTA.

320-row CT coronary angiography predicts freedom from revascularisation and acts as a gatekeeper to defer invasive angiography in stable coronary artery disease: a fractional flow reserve-correlated study.

Objectives: To determine the accuracy of 320-row multidetector coronary computed tomography angiography (M320-CCTA) to detect functional stenoses using fractional flow reserve (FFR) as the reference standard and to predict revascularisation in stable coronary artery disease.

Methods: One hundred and fifteen patients (230 vessels) underwent M320-CCTA and FFR assessment and were followed for 18 months. Diameter stenosis on invasive angiography (ICA) and M320-CCTA were assessed by consensus by two observers and significant stenosis was defined as ≥50%.

Radiation dose in 320-slice multidetector cardiac CT: a single center experience of evolving dose minimization.

Background: Minimization of radiation exposure remains an important subject that occurs in parallel with advances in scanner technology.

Objective: We report our experience of evolving radiation dose and its determinants after the introduction of 320-multidetector row cardiac CT within a single tertiary cardiology referral service.

Methods: Four cohorts of consecutive patients (total 525 scans), who underwent cardiac CT at defined time points as early as 2008, are described.

Dynamic volumetric computed tomographic assessment of the young paediatric airway: Initial experience of rapid, non-invasive, four-dimensional technique.

Introduction: The aim of this study was to evaluate the dynamic volumetric CT in the assessment of the paediatric airway.

Methods: Ethics board approval was obtained for this retrospective review. Eight infants (median age 6 months, range 3 weeks to 1 year, 50% female) at a tertiary paediatric centre with complex clinical respiratory presentation underwent volumetric CT assessment of their airways.

Transluminal attenuation gradient in coronary computed tomography angiography is a novel noninvasive approach to the identification of functionally significant coronary artery stenosis: a comparison with fractional flow reserve.

Objective: The purpose of this study was to assess the diagnostic accuracy of TAG320 in predicting functional stenosis severity evaluated by fractional flow reserve (FFR).

Background: Coronary computed tomography angiography (CCTA) has limited specificity for predicting functionally significant stenoses. Recent studies suggest that contrast gradient attenuation along an arterial lesion, or transluminal attenuation gradient (TAG), may provide assessment of functional significance of coronary stenosis.

Combined CT coronary angiography and stress myocardial perfusion imaging for hemodynamically significant stenoses in patients with suspected coronary artery disease: a comparison with fractional flow reserve.

Objectives: We sought to determine the accuracy of combined coronary computed tomography angiography (CTA) and computed tomography stress myocardial perfusion imaging (CTP) in the detection of hemodynamically significant stenoses using fractional flow reserve (FFR) as a reference standard in patients with suspected coronary artery disease.

Background: CTP can be qualitatively assessed by visual interpretation or quantified by the transmural perfusion ratio determined as the ratio of subendocardial to subepicardial contrast attenuation. The incremental value of each technique in addition to coronary CTA to detect hemodynamically significant stenoses is not known.

Normal perfusion of the left ventricular myocardium using 320 MDCT.

Background: CT myocardial perfusion imaging is an emerging CT application using density measurements of contrast-enhanced left ventricular (LV) myocardium.

Objective: Using a 320-MDCT we have consistently observed lower Hounsfield unit (HU) values in the lateral LV myocardium, potentially mimicking perfusion defects. This study aimed to evaluate contrast-enhancement patterns of the LV myocardium in normal studies.

Computed tomography stress myocardial perfusion imaging in patients considered for revascularization: a comparison with fractional flow reserve.

Aims: Adenosine stress computed tomography myocardial perfusion imaging (CTP) is an emerging non-invasive method for detecting myocardial ischaemia. Its value when compared with fractional flow reserve (FFR), a highly accurate index of ischaemia, is unknown. Our aim was to determine the diagnostic accuracy of CTP and its incremental value when used with computed tomography coronary angiography (CTA) for detecting ischaemia compared with FFR.

Acute chest pain investigation: utility of cardiac CT angiography in guiding troponin measurement.

Purpose: To assess the impact on length of stay and rate of major adverse cardiovascular events of a cardiac computed tomographic (CT) angiography-guided algorithm to examine patients who present to the emergency department (ED) with low- to intermediate-risk chest pain.

Materials And Methods: The study was approved by the institutional review board, and all patients gave written informed consent. Two hundred three consecutive patients (mean age, 55 years ± 11 [standard deviation]; 123 men) with low- to intermediate-risk ischemic-type chest pain were prospectively enrolled.

Coronary image quality of 320-MDCT in patients with heart rates above 65 beats per minute: preliminary experience.

Objective: High heart rate may negatively influence the image quality of cardiac CT. The technical advances of 320-MDCT may overcome issues with poor image quality associated with high heart rate. This study aimed to evaluate the coronary image quality of 320-MDCT in patients with heart rates above 65 beats/min.

Abnormal vocal cord function in difficult-to-treat asthma.

Rationale: Upper airway dysfunction may complicate asthma but has been largely ignored as an etiological factor. Diagnosis using endoscopic evaluation of vocal cord function is difficult to quantify, with limited clinical application.

Objectives: A novel imaging technique, dynamic 320-slice computerized tomography (CT), was used to examine laryngeal behavior in healthy individuals and individuals with asthma.

Presence of accessory left atrial appendage/diverticula in a population with atrial fibrillation compared with those in sinus rhythm: a retrospective review.

Accessory left atrial appendages and atrial diverticula have an incidence of 10-27%. Their association with atrial fibrillation needs to be confirmed. This study determined the prevalence, number, size, location and morphology of accessory left atrial appendages/atrial diverticula in patients with atrial fibrillation compared with those in sinus rhythm.

Diagnostic accuracy of noninvasive coronary angiography with 320-detector row computed tomography.

We sought to evaluate the diagnostic accuracy of noninvasive coronary angiography using 320-detector row computed tomography, which provides 16-cm craniocaudal coverage in 350 ms and can image the entire coronary tree in a single heartbeat, representing a significant advance from previous-generation scanners. We evaluated 63 consecutive patients who underwent 320-detector row computed tomography and invasive coronary angiography for the investigation of suspected coronary artery disease. Patients with known coronary artery disease were excluded.

Comparison of 4 cm Z-axis and 16 cm Z-axis multidetector CT perfusion.

Objective: The aim of the study was to compare 4 cm with 16 cm Z-axis coverage in the assessment of brain CT perfusion (CTP) using. 320 slice multidetector CT METHODS: A retrospective non-randomised review of CTP performed on MD320 CT between September 2008 and January 2009 was undertaken. Two experienced readers reviewed the studies along with the 4 cm and 16 cm Z-axis CTP image data set.