Multidetector Computed Tomography Parameters Research Articles

Impact of a reduced iodine load with deep learning reconstruction on abdominal MDCT.

To evaluate the impact of a reduced iodine load using deep learning reconstruction (DLR) on the hepatic parenchyma compared to conventional iterative reconstruction (hybrid IR) and its consequence on the radiation dose and image quality. This retrospective monocentric intraindividual comparison study included 66 patients explored at the portal phase using different multidetector computed tomography parameters: Group A, hybrid IR algorithm (hybrid IR) and a nonionic low-osmolality contrast agent (350 mgI/mL); Group B, DLR algorithm (DLR) and a nonionic iso-osmolality contrast agent (270 mgI/mL). We recorded the attenuation of the liver parenchyma, image quality, and radiation dose parameters. The mean hounsfield units (HU) value of the liver parenchyma was significantly lower in group B, at 105.9 ± 10.9 HU versus 118.5 ± 14.6 HU in group A. However, the 90%IC of mean liver attenuation in the group B (DLR) was between 100.8 HU and 109.3 HU. The signal-to-noise ratio of the liver parenchyma was significantly higher on DLR images, increasing by 56%. However, for both the contrast-to-noise ratio (CNR) and CNR liver/PV no statistical difference was found, even if the CNR liver/PV ratio was slightly higher for group A. The mean dose-length product and computed tomography dose index volume values were significantly lower with DLR, corresponding to a radiation dose reduction of 36% for the DLR. Using a DLR algorithm for abdominal multidetector computed tomography with a low iodine load can provide sufficient enhancement of the liver parenchyma up to 100 HU in addition to the advantages of a higher image quality, a better signal-to-noise ratio and a lower radiation dose.

Computed tomography is better than echocardiography in predicting balloon-expandable transcutaneous implantation valve size in a real-world clinical practice single-center study.

Transcatheter aortic valve replacement (TAVR) has become the standard of care for selected patients with severe aortic stenosis. Multidetector computed tomography (MDCT) and transoesophageal 2D/3D (two-dimensional/three-dimensional) echocardiography (ECHO) are used for aortic annulus (AA) sizing. The aim of this study was to compare the accuracy of AA sizing by ECHO versus MDCT for Edwards Sapien balloon expandable valve in a single center. Data from 145 consecutive patients with TAVR (Sapien XT or Sapien S3) were analyzed retrospectively. A total of 139 (96%) patients had favorable outcomes after TAVR (at most mild aortic regurgitation and only one valve implanted). The 3D ECHO AA area and area-derived diameter were smaller than the corresponding MDCT parameters (464±99 vs. 479±88mm2 , p<.001, and 24.2±2.7 vs. 25.0±5.5mm, p=.002, respectively). The 2D ECHO annulus measurement was smaller than both the MDCT and 3D ECHO area-derived diameters (22.6±2.9 vs. 25.0±5.5mm, p=.013, and 22.6±2.9 vs. 24.2±2.7mm, p<.001, respectively) but larger than the minor axis diameter of the AA derived from MDCT and 3D ECHO by multiplanar reconstruction (p<.001). The 3D ECHO circumference-derived diameter was also smaller than the MDCT circumference-derived diameter (24.3±2.5 vs. 25.0±2.3, p=.007). The sphericity index by 3D ECHO was smaller than that by MDCT (1.2±.1 vs. 1.3±.1, p<.001). In up to 1/3 of the patients, 3D ECHO measurements would have predicted different (generally smaller) valve size than was the valve size implanted with favorable result. The concordance of the implanted valve size with the recommended size based on preprocedural MDCT and 3D ECHO AA area was 79.4% versus 61% (p=.001), and for the area-derived diameter, the concordance was 80.1% versus 61.7% (p=.001). 2D ECHO diameter concordance was similar to MDCT (78.7%). 3D ECHO AA measurements are smaller than MDCT measurements. If 3D ECHO-based parameters alone are used to size the Edwards Sapien balloon expandable valve, then the selected valve size would have been smaller than the valve size implanted with favorable result in 1/3 of the patients. MDCT preprocedural TAVR assessment should be the preferred method over 3D ECHO in routine clinical practice to determine Edwards Sapien valve size.

Usefulness of Computed Tomography to Predict Mitral Stenosis After Transcatheter Mitral Valve Edge-to-Edge Repair

Multidetector computed tomography (MDCT) can provide valuable information for preprocedural planning of transcatheter mitral valve interventions. However, no data exists on pre-MDCT parameters predicting high transmitral pressure gradient (TMPG) post-MitraClip procedure. We analyzed the preprocedural MDCTs of 156 consecutive patients with mitral regurgitation undergoing MitraClip implantation at our institution. The mean TMPG was assessed by periprocedural transesophageal and pre-discharge transthoracic echocardiography. MDCT-derived mitral annulus area (MAA), anterior-posterior (AP) and medial-lateral (ML) mitral annulus diameters, and mitral valve orifice area (MVOA) were smaller in patients with mean TMPG ≥5 mmHg than those with mean TMPG <5 mmHg after 1-or 2-clip implantation. Small MAA, AP and ML diameters, and MVOA were moderately correlated with high TMPG post-MitraClip, in which MAA and MVOA had the highest degree of correlation after 1-clip (r=-0.46 both), whereas MAA and ML had the strongest degree of correlation after 2-clip (r=-0.39 both) and at discharge (r=-0.38 both). From the receiver-operating-characteristic curve analyses, no significant differences in the area under the curve were observed among these MDCT parameters for low TMPG after MitraClip implantation, except for those between MAA and AP diameter at discharge (p=0.026). For optimal cutoff values, MAA ≥1100 and ≥1300 mm2 had positive predictive values of 89% and 91%, while both MAA ≥750 and ≥900 mm2 had negative predictive values of 100%, for mean TMPG <5 mmHg after 1-and 2-clip implantation, respectively. In conclusion, in patients undergoing the MitraClip procedure, preprocedural MDCT parameters are useful to predict postprocedural mitral stenosis.

Abstract 17472: Association of Recurrence During Blanking Period With Poor Left Atrial Reverse Remodeling After Initial Catheter Ablation of Non-paroxysmal Atrial Fibrillation: Their Impact on the Clinical Outcome

Background: Left atrial reverse remodeling (LARR) after catheter ablation (CA) to atrial fibrillation (AF) indicates reduction of AF substrates in left atrium (LA). In this study, we investigated the impact of LARR on the outcome after CA of non-paroxysmal AF (non-PAF; persistent AF and long-standing persistent AF) and determined the predictor of LARR. Methods and Results: Consecutive 303 patients who underwent initial CA of non-PAF in our institute were retrospectively analyzed. We performed multi-detector computed tomography (MDCT) to evaluate LA end-systolic volume (LAESV) before and 90 days after CA. We determined LARR using %LA reduction [defined as (pre LAESV - post LAESV) / pre LAESV x100]. The average %LA reduction was 20.2±16.8% (median 22.2%). Then we divided them into LARR group (%LA reduction &gt;20%, N=167) and non-LARR group (%LA reduction&lt;20%, N=136). We followed them for 630±153 days to observe their recurrence rate after 90 days blanking period (BP). The recurrence was less frequently observed in LARR group than non-LARR (31.1% vs 56.4%, p&lt;0.01, log-rank test). Next, we examined the predictor of LARR. In univariate analysis, there were no significant differences in age, sex, CHADS2 score, AF duration before CA, anti-arrhythmic drug administration after CA, CA procedure, echocardiographic data and MDCT parameters. Only the recurrence rate during BP was significantly smaller in LARR than non-LARR (43% vs 61%, p=0.002). Then, we divided BP into three parts, early BP, mid BP and late BP (within 7 days, 8 to 30 days, and 31 to 90 days after CA, respectively). The recurrence rate in LARR group was lower than in non-LARR during early BP (27.5% vs 36.8%, p=0.09), mid BP (30.5% vs 42.6%, p=0.03), and late BP (9.0% vs 31.6%, p&lt;0.01). In multivariable analysis, recurrence in late BP revealed to be the predictor of LARR (odds ratio 0.19, [95% confidence interval: 0.10-0.37]). Conclusions: The LARR was associated with better clinical outcome. The absence of recurrence during late BP (31-90 days after CA) was the strong predictor of LARR. These parameters can be acquired at the time point of 3 months after CA and they may be useful for predicting the CA results. Recurrence during late BP might be one of the causes of the poor LARR after CA for non-PAF.

Automatic Airway Analysis on Multidetector Computed Tomography in Cystic Fibrosis

To evaluate the fully automatic quantification of airway dimensions on chest multidetector computed tomography (MDCT) performed in cystic fibrosis (CF) patients. Airflow indices including predicted forced expiratory volume in 1 second (FEV1%) were used to study the impact on regional lung function. MDCT data of patients with CF (14 children and 23 adults) and of control patients (11 children and 22 adults) were used to compute total diameter (TD), lumen area (LA), and wall thickness (WT) using dedicated software. Pulmonary function testing including FEV1% was performed in parallel and correlated with MDCT parameters in a generation-based analysis. TD was largely increased in CF patients (third-generation to fourth-generation airways in children, first to ninth in adults; P<0.05). LA remained unchanged, but WT was also larger in CF compared with controls (third generation to sixth generation in children, first to eleventh in adults; P<0.05). In adult CF patients significant negative correlations for TD, LA, and WT with FEV1% were found for intermediate airways (fifth to seventh generation; r=-0.7 to -0.9) but not in pediatric CF patients and controls. Automatic airway analysis succeeded in quantifying specific pathologies such as airway dilatation and wall thickening in CF patients at different ages. Moreover, our results indicate a shift in main airflow resistance to intermediate airways in cases of chronic CF. The objective computational parameters TD, LA, and WT should be considered for assessment and follow-up of CF airway disease.

Early detection of premature subclinical coronary atherosclerosis in systemic lupus erythematosus patients

Abstract Objective To elucidate early coronary atherosclerotic changes in premenopausal systemic lupus erythematosus (SLE) female patients without clinical cardiovascular manifestation using a 64-slice Multi-detector computed tomography (MDCT) scan to detect coronary calcification and measure coronary calcium score (CCS), and to find out its correlation to some traditional and non-traditional risk factors. Methodology Sixty consecutive premenopausal SLE female patients, and sixty age and sex matched healthy subjects without known systemic, immunological, or cardiovascular disease (served as a control group) underwent clinical examination, serological analysis, and 64-slice MDCT-based coronary calcium scoring. All the clinical, serological, and MDCT parameters of the patients were correlated. Results Coronary calcification (CC) was seen in 21 patients (35%), the number of atherosclerotic calcified plaques ranged from 0 to 19. Calcium scores ranged from 0 to 843. In contrast to control subjects, SLE patients had significantly higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), total cholesterol level, low-density lipoprotein (LDL), immunoglobulin G (IgG) and IgM anti-cardiolipin antibodies, serum intracellular adhesion molecule (sICAM) and E-selectin levels. SLE patients had highly significantly more atherosclerotic plaques (3 ± 0.66 compared to 0.1 ± 0.07, p p p Conclusion Pre-menopausal SLE female patients free from clinical atherosclerotic vascular disease have an increased number of atherosclerotic plaques and CCS, which correlate positively with SLEDAI disease activity score, serum CRP, anticardiolipin antibodies, sICAM-1, E-Selectin, LDL level, total cholesterol level, and cumulative prednisone dose. In addition, we conclude that MDCT is a non-invasive, sensitive, reproducible, and reliable tool for accurate measurement of coronary calcification.

Multidetector Computed Tomography for Detection and Characterization of Pulmonary Hypertension in Consideration of WHO Classification

We evaluated the reliability of various multidetector computed tomography (MDCT) parameters for diagnosis and severity assessment of pulmonary hypertension (PH) with consideration of World Health Organization (WHO) classification. A total of 172 patients were included in this retrospective study. One hundred fourteen patients had a diagnosis of PH (mean pulmonary artery pressure ≥25 mm Hg), and 58 patients without PH (mean pulmonary artery pressure <20 mm Hg) served as control subjects. The patients with PH were grouped according to the WHO classification based on PH etiology. The patients with PH had significantly greater main, left, and right pulmonary artery diameters than the control subjects (P < 0.001). No significant differences within the PH subgroups were found. Receiver operating characteristic analysis showed reasonable sensitivity and specificity for selected MDCT parameters. The severity of PH did not correlate with MDCT parameters. Easy-to-determine MDCT parameters allow detection of PH independent of the WHO group. In patients with dilated aorta, the vertebra can be an alternative internal standard. Severity of PH cannot be estimated by MDCT parameters.

Estimation of Left Atrial Pump Function by Mitral Annular Velocity

Estimation of left atrial (LA) pump function is important for the management of cardiac patients. The purpose of this study is to elucidate the role of mitral annular late diastolic velocity (A') determined by transthoracic echocardiography as a parameter to predict LA pump function. One hundred and four consecutive patients that were scheduled for paroxysmal atrial fibrillation (AF) ablation, in whom both multi-detector computed tomography (MDCT) and echocardiography during sinus rhythm prior to ablation were performed, were enrolled in this study. To determine the echocardiographic parameters that most accurately represent LA pump function, the relationship between LA emptying fraction (LAEF) obtained by MDCT and echocardiographic parameters including A' were examined. A' was the only echocardiographic parameter that was significantly correlated with LAEF (r=0.59, P<0.0001). Receiver-operating characteristic curve analysis showed that when impaired LA booster pump performance was defined as an LAEF <30%, an A' cutoff value of 7.4 cm/s had a sensitivity of 93%, specificity of 81%, predictive accuracy of 83%, positive predictive value of 43% and a negative predictive value of 99%. A' is a simple, non-invasive and reliable method to estimate LA pump function in patients with paroxysmal AF.

Integration of 3D Imaging Data in the Assessment of Aortic Stenosis

Background— In patients with aortic stenosis (AS), precise assessment of severity is critical for treatment decisions. Estimation of aortic valve area (AVA) with transthoracic echocardiographic (TTE)-continuity equation (CE) assumes a circular left ventricular outflow tract (LVOT). We evaluated incremental utility of 3D multidetector computed tomography (MDCT) over TTE assessment of AS severity. Methods and Results— We included 51 patients (age, 81±8 years; 61% men; mean gradient, 42±12 mm Hg) with calcific AS who underwent evaluation for treatment options. TTE parameters included systolic LVOT diameter (D) and continuous and pulsed wave (CW and PW) velocity-time integrals (VTI) through the LVOT and mean transaortic gradient. MDCT parameters included systolic LVOT area, ratio of maximal to minimal LVOT diameter (eccentricity index), and aortic planimetry (AVA p ). TTE-CE AVA [(D 2 ×0.786×VTIpw)/VTIcw] and dimensionless index (DI) [VTIpw/VTIcw] were calculated. Corrected AVA was calculated by substituting MDCT LVOT area into CE. The majority (96%) of patients had eccentric LVOT. LVOT area, measured on MDCT, was higher than on TTE (3.84±0.8 cm 2 versus 3.03±0.5 cm 2 , P &lt;0.01). TTE-AVA was smaller than AVA p and corrected AVA (0.67±0.1cm 2 , 0.82±0.3 cm 2 , and 0.86±0.3 cm 2 , P &lt;0.01). Using TTE measurements alone, 73% of patients had congruence for severe AS (DI ≤0.25 and CE AVA &lt;0.8 cm 2 ), which increased to 92% using corrected CE. Conclusions— In patients with suspected severe AS, incorporation of MDCT-LVOT area into CE improves congruence for AS severity.

Three-Dimensional Quantitative Volumetry of Chronic Total Occlusion Plaque Using Coronary Multidetector Computed Tomography

The purpose of the present study was to investigate whether multidetector computed tomography (MDCT) can identify the nature of chronic total occlusion (CTO) plaque, which cannot be measured quantitatively using traditional coronary angiography, and predict the success of percutaneous coronary intervention (PCI). MDCT and 3-dimensional volumetric radiologic density analysis was performed for 186 consecutive CTO lesions. Plaque characteristics were determined using Hounsfield units (HU) of the image voxels. The remodeling index decreased significantly as the duration of CTO lengthened. Volumetric plaque analysis using HU showed that volumetric fraction of calcification (>324HU) did not, but low-density plaque (<49HU) did decrease significantly as the duration of CTO lengthened. The overall PCI success rate was 77.4% (144/186). In addition to the unknown or >12-month occlusion duration (odds ratio [OR]=3.0, 95% confidence interval [CI]=1.4-6.5, P=0.005), 2 MDCT parameters, that is, lesion length >18mm (OR=2.7, 95%CI=1.1-6.4, P=0.024) and segmental radiologic density >139HU (OR=2.7, 95%CI=1.2-6.4, P=0.021), were independent predictors of PCI failure on multivariate analysis. MDCT might be helpful for the prediction of successful CTO PCI. In addition to the occlusion duration, lesion length and high segmental radiologic density measured on MDCT were significant predictors of PCI failure in the present study.

Quantification of regional calcium burden in chronic total occlusion by 64-slice multi-detector computed tomography and procedural outcomes of percutaneous coronary intervention

One of the most important reasons for failure of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is calcified plaque, which either prevents passage of guide wire or ruptures after balloon inflation. We sought to evaluate whether quantified calcium contents of CTO on multi-detector computed tomography (MDCT) correlate with immediate procedural outcomes. Sixty-four patients with 72 CTO lesions who underwent 64-slice MDCT prior to PCI were investigated. The lesions were divided into 2 groups according to procedural outcomes (55 lesions with PCI-success group, 17 lesions with PCI-failure group). Clinical, angiographic and MDCT parameters, including regional calcium volume (RCaV), regional calcium score (RCaS), regional calcium equivalent mass (RCaEq), and relative calcium area at the most calcified cross section of CTO (%CaS/CSA), were compared between the two groups. The duration of CTO was shorter in PCI-success group than PCI-failure group (7.16 ± 10.5 vs 15.59 ± 14.92 months, p=0.011), and the procedural success rate was 76.3%. Regional calcium-related parameters (RCaV 52.86 ± 58.39 vs 7.26 ± 15.27 mm(3), p<0.001; RCaS 72.71 ± 78.4 vs 9.66 ± 20.2, p<0.001; RCaEq 12.58 ± 12.97 vs 1.84 ± 3.716 mgCaHA, p<0.001; %CaS/CSA 53.9 ± 20.3 vs 30.4 ± 17.1%, p=0.009) in the occluded segment were higher and the occlusion length was longer (37.44 ± 27.48 vs 22.00 ± 18.04 mm, p<0.021) in PCI-failure group compared to PCI-success group. Multivariate regression analysis showed that only %CaS/CSA was a significant determinant of PCI-failure. Precise quantification of regional calcification and measurement of the occluded segment by high resolution MDCT can deliver important information for predicting procedural outcomes in PCI of CTO.

Hemodynamic Depression During Carotid Angioplasty With Stenting

To investigate potential risk factors for hemodynamic depression (HD) in elective carotid angioplasty with stenting (CAS) by using multidetector computed tomography (MDCT) angiographic findings and clinical data. A retrospective study was conducted for 32 patients that underwent MDCT angiography before CAS in our hospital. We reviewed the MDCT angiographic findings to evaluate parameters including total plaque volume, composition and the composition ratio of plaque, degree of stenosis, and distance of the most stenotic portion from carotid bifurcation. Clinical data such as patient age, presence of neurological symptoms, underlying medical disease, smoking history, and previous stroke history were noted. The MDCT angiographic parameters and clinical data were then analyzed to determine a prediction for periprocedural HD (systolic blood pressure, <90 mm Hg; or heart rate, <40 beats/min). Periprocedural HD was observed in 9 patients (28.1%). Among the MDCT angiographic parameters, the hemodynamic unstable group of patients had a smaller total plaque volume than that of stable group of patients (P = 0.04). The other MDCT parameters and clinical data did not show statistically significant difference between 2 groups. In this study, only the total volume of plaque was a positive factor for predicting HD during CAS. Multidetector computed tomography angiography can be helpful for predicting HD during CAS.

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We found an artifact of the Stereotactic Body Frame's (SBF) indicators when we used diagnostic 16-row multi-detector computed tomography (MDCT) as a simulator. Stereotactic radiotherapy (SRT) requires the accuracy of each millimeter. However, a gap of 3 mm at the maximum along the Z axis was caused by this artifact. We assessed the characteristics and cause of this artifact and searched for an imaging parameter to reduce the artifact in SRT. It was considered that the artifact was formed mainly by a stair-step artifact and cone-beam artifact. We can acquired accuracy, 1 mm minimizing the beam width and pitch (10 mm/0.5625). However, exposure time was extended because minimum pitch was selected. The influence on dose calculation was negligible. We decided to use a default parameter for treatment planning, and this parameter for determining the isocenter. We found the MDCT parameters to get acceptable positional accuracy for SRT with SBF.