Risultati per: L'imaging nella urolitiasi

Circulation, Volume 148, Issue Suppl_1, Page A18674-A18674, November 6, 2023. Introduction:Mitral valve prolapse (MVP) has a high population prevalence 2-4% with an arrhythmogenic subtype presenting with premature ventricular complexes (PVC) ventricular tachycardia (VT) and sudden death. There is a continued search for markers of MVP to help risk stratify patients.Hypothesis:Arrhythmogenic MVP shares genetic etiology with Mendelian causes of arrhythmia and cardiomyopathyMethods:Consecutive adult patients with arrhythmogenic MVP patients prospectively evaluatedResults:A total of 33 cases (age 55±15 years, female 51.5%) presented with history of hypertension (33%), diabetes (3%), coronary disease (12%), atrial fibrillation (45%), bileaflet MVP (58%) and syncope (18%). ECG findings include inverted T-waves in inferior leads in 6%, pleomorphic PVC in 6%, Ventricular couplets in 51.5%, non-sustained VT in 73% and sustained VT in 33%; High PVC burden was seen in 55% of cases with burden 15±14%. Echocardiography noted LV ejection fraction of 55±8%, mitral regurgitations in 70% (severe 18%, moderate 27%, mild 24%), mitral annular disjunction in 39%, and Pickelhaube sign in 9% of cases. Cardiac magnetic resonance showed LVESV 113±119mm, LVEDV 117±70mm, and late Gadolinium enhancement in 48% with highest prevalence in basal inferolateral segment. PET-CT performed in 17 cases and showed fluorodeoxyglucose uptake in 24% cases, mostly in basal inferolateral segment as well. Genetic testing was performed in 23 cases and reported a putative pathogenic variant in 21.7%:FLNC(Exemplar case,Figure 1) cause of dilated cardiomyopathy,TBX5cause of Holt-Oram syndrome,DSPcause of arrhythmogenic cardiomyopathy, TTNcauses of dilated cardiomyopathy,MTO1cause of mitochondrial hypertrophic cardiomyopathy.Conclusion:Full evaluation of arrhythmogenic MVP with multimodality imaging and genetic testing reveals high burden of fibrosis, inflammation, and candidate pathogenic variants.

Circulation, Volume 148, Issue Suppl_1, Page A16057-A16057, November 6, 2023. Introduction:Advanced imaging with cardiac magnetic resonance (CMR) or computed tomography (CCT) can be helpful for planning of ventricular tachycardia (VT) ablation procedures by defining the arrhythmogenic substrate. The frequency with which these modalities are utilized in the pre-ablation setting and the associated outcomes remain poorly studied.Objectives:(1) Determine the utilization of advanced cardiac imaging prior to structural VT ablation; (2) establish factors associated with improved VT ablation outcomesMethods:We retrospectively evaluated all VT ablations performed in patients with structural heart disease at a tertiary referral institution during a 2.5 year period (1/2020 – 7/2022). We documented pre-ablation use of cardiac imaging modalities and investigated their association with acute and long-term ablation outcomes. The primary outcome was time to VT recurrence, cardiac transplant, or death.Results:Our dataset included n = 129 subjects. Median post-ablation follow-up was 17 months. Recent echocardiogram, CMR, or CCT (

Circulation, Volume 148, Issue Suppl_1, Page A11914-A11914, November 6, 2023. Introduction:The relative diagnostic and prognostic performance of left ventricular global longitudinal strain (LVGLS) as compared to LV ejection fraction (LVEF), and the role of LVGLS for detecting early stages of LV systolic dysfunction in adults with repaired coarctation of aorta (COA) is unknown.Objective:The purpose of this study was to address these knowledge gaps.Methods:Retrospective cohort study of adults with repaired COA that underwent transthoracic echocardiogram (2003-2020). LV systolic function was assessed using LVEF (derived from volumetric analysis) and LVGLS (derived from speckle-tracking echocardiography).Results:Of the 795 patients (age 36±14 years), mean LVEF and LVGLS were 62±11%, and 21±4%, respectively. The prevalence of LV systolic dysfunction was higher when assessed using LVGLS as compared to LVEF (20% versus 6%, p

Circulation, Volume 148, Issue Suppl_1, Page A17309-A17309, November 6, 2023. Introduction:Serial positron emission tomography (PET) imaging is utilized to monitor disease activity and treatment response in patients with suspected cardiac sarcoidosis (CS). However, there is no data available on the cardiovascular outcomes associated with corticosteroid taper rates and timing of repeat PET imaging in patients with CS.Methods:We identified 70 patients with suspected CS (Age: 56.3 ± 9, 31% female, LVEF 45.6 ± 13.6, median follow-up time: 6.3 months [4-7.6]) who were treatment naïve and displayed inflammation on baseline FDG-PET, subsequently started on a moderate-dose of prednisone only (i.e., 30-40 mg/day), and had a diagnostic follow-up PET. Patients were divided into two groups based on median follow-up time between PET scans; early (

Circulation, Volume 148, Issue Suppl_1, Page A13712-A13712, November 6, 2023. Introduction:Heart failure compromises the transport and oxidation of long chain fatty acids. Cardiomyocytes can compensate by using short-chain fatty acids (SCFA) which rely on other transport mechanisms. Based on this principle, we used 2-[18F]fluoropropionic acid ([18F]FPA), a radiolabeled SCFA analog, to assess these metabolic changes and image them by positron emission tomography (PET) in a doxorubicin-induced mouse model of cardiotoxicity.Hypothesis:We hypothesize that the increased demand for SCFA by the failing heart promotes cardiac accumulation of [18F]FPA which can be imaged by PET.Methods:[18F]FPA was injected intravenously into male C57BL/6J mice 10 weeks following intraperitoneal injections of 8 x 3 mg/kg doxorubicin (DOX). Dynamic PET acquisitions were performed from 60-120 min post injection of 9.25-11 MBq [18F]FPA. These images were acquired in the presence or absence of 5 mg/kg AZD3965, an inhibitor of monocarboxylate transporters. Heart uptake of [18F]FPA was determined by image-based quantitation and confirmed by a biodistribution study. Mechanistic [18F]FPA uptake studies were also conducted in primary human cardiomyocyte (HCM) cultures.Results:Mice experiencing DOX-induced cardiotoxicity exhibited statistically significant increases in cardiac [18F]FPA. AZD3965 did not significantly alter cardiac uptake but reduced uptake in all other tissues except the kidneys, the route of excretion. Additionally, [18F]FPA uptake is lost in HCM for which mitochondrial acyl-CoA synthetase (ACSS) 1, but not cytosolic ACSS2, is inhibited.Conclusions:Our findings present both mechanistic and translational applications for [18F]FPA. AZD3965 effectively reduced [18F]FPA uptake in other tissues except for the heart and can therefore be co-administered to enhance the heart-to-background ratio. Altogether, our results indicate that [18F]FPA may enter cardiac tissues by diffusion and become metabolically trapped in mitochondria.

Circulation, Volume 148, Issue Suppl_1, Page A14190-A14190, November 6, 2023. Introduction:Intra-left ventricular (LV) blood flow dynamics is closely related to wall kinetics and myocardial perfusion. 4D flow magnetic resonance imaging (MR) has been developed to simulate and quantify intra-LV blood flow. We aimed to evaluate the usefulness of simultaneous analysis of myocardial flow reserve (MFR) and intra-LV 4D flow measured by hybrid13N-ammonia positron emission tomography (PET)/MR in patients with coronary artery disease (CAD).Methods:Forty patients (mean 65±18 years, male 32) with CAD who underwent pharmacological stress PET/MR were enrolled. MFR was calculated from a series of dynamic rest-stress PET scans. Simultaneously, 4D flow MR acquisition was performed during the stress PET scan. The intra-LV 4D flow was visually assessed, where the smooth flow was defined as normal pattern, and random, or reverse flow was defined as abnormal (Figure A). The velocity of LV inflow and outflow were measured.Results:A normal flow pattern was found in 22 patients, while abnormal pattern was found in 18. MFR showed a significant correlation with the velocity of LV inflow and outflow (inflow: R = 0.552, P < 0.001; outflow: R = 0.563, P < 0.001). MFR was significantly lower in the abnormal flow compared to the normal flow (1.484 ± 0.559 vs. 1.931 ± 0.775, P = 0.041, Figure B). Additionally, when analyzing MFR in coronary artery territories, MFR in the left anterior descending artery was significantly lower in the abnormal flow compared to the normal flow (1.405 ± 0.526 vs. 1.881 ± 0.791, P = 0.029, Figure C).Conclusion:Simultaneous analysis of MFR and intra-LV 4D flow has a potential to serve as a novel indicator for assessing the severity of ischemia in patients with CAD.

Circulation, Volume 148, Issue Suppl_1, Page A17831-A17831, November 6, 2023. Introduction:The ability to track leucocyte – endothelium interactions using non-invasive imaging could allow early diagnosis and monitoring of disease activity in vascular disorders. To this aim, we can use magnetic particle imaging (MPI), a new imaging modality that can detect superparamagnetic material in the human body with high sensitivity.Hypothesis:Superparamagnetic microparticles of iron oxide (MPIO) targeted to endothelial adhesion molecules could be used as leucocyte-mimicking particle and reveal the sites of leucocyte – endothelium interactions by MPI.Methods:We synthesized MPIO targeted to vascular cell adhesion molecule 1 (VCAM-1). These MPIO@VCAM-1 were characterized in vitro by transmission electronic microscopy, flow cytometry and flow chamber experiments. Then, we performed in vivo imaging in models of vascular inflammation in mice, including sepsis and neurovascular inflammation. MPI was performed using a MPI/CT system (Momentum CT, Magnetic Insight).Results:MPIO@VCAM-1 bind specifically to activated endothelial cells in vitro. In control mice, intravenously injected MPIO@VCAM-1 are rapidly eliminated from the circulation by the reticulo-endothelial system and accumulate in the liver and spleen. In LPS-induced sepsis, MPIO@VCAM-1 bind in the lungs and kidneys in a dose dependent manner, revealing inflammation (Figure 1a-b). In conditions of neurovascular inflammation, MPIO@VCAM-1 accumulate on activated endothelial cells of inflamed brain regions (Figure 1c-f). In all these models, control MPIO@IgG do not give any signal beyond passive accumulation in the liver. Moreover, pre-treatment with blocking anti-VCAM-1 antibodies completely abrogates MPIO@VCAM-1 binding, demonstrating imaging specificity.Conclusions:MPI using MPIO@VCAM-1 reveals sites of leucocyte trafficking, allowing quantitative assessment of leucocyte – endothelium interactions in clinically relevant contexts.

Circulation, Volume 148, Issue Suppl_1, Page A18692-A18692, November 6, 2023. Introduction:FDG-PET imaging is standard for assessing myocardial inflammation for cardiac sarcoidosis (CS). Preparation with the ketogenic diet (KD) is required to suppress physiologic myocardial glucose uptake (MGU), thereby highlighting pathologic MGU. Incomplete physiologic myocardial glucose suppression (MGS) continues to limit FDG-PET. The effect of fasting time (FT) on MSG remains unexplored.Goal:To identify if FT is an independent predictor of MGS following a KD in patients undergoing FDG-PET imaging.Methods:We prospectively included 442 consecutive patients (59.2 ± 10.9 yrs, 39% female, 55% white) who underwent 590 FDG-PET scans for the evaluation of CS after following a KD at our institution between 2021 and 2023. Time from last meal to FDG injection was documented in all patients. Serum BHB levels were measured in 516 scans. FDG PET images were classified as 1) diagnostic (complete MGS) when there was either no MGU (negative) or multifocal uptake (positive), or 2) nondiagnostic (incomplete MGS) when there was either diffuse left ventricular or nonspecific uptake.Results:The KD was followed for 1, 2 or ≥3 days in 127 (22%), 61 (10%), and 402 (68%) of cases respectively. FDG-PET scans were interpreted as the following: 436 (74%) negative; 109 (18.3%) positive; 13 (2.2%) diffuse; 32 (5.4%) nonspecific uptake. Patients on the KD for only 1 day had higher rates of MGS with increased FT (β = 0.33 ± 0.11, p

Circulation, Volume 148, Issue Suppl_1, Page A14964-A14964, November 6, 2023. Background:It is currently unclear whether various measurements of the aortic valvular complex routinely performed on pre-operative computed tomography angiograms (CTA) can collectively predict the risk of conduction disturbances after transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS). Here, we aimed to use unsupervised machine learning to analyze a multitude of CTA features and identify distinct patient sub-phenotypes with different risks for TAVR-related conduction disturbances.Methods:The pre-TAVR CTAs of 660 AS patients (330 males, 330 females) were analyzed using TeraRecon to extract 21 features that included aortic valve leaflet calcification loads, dimensions of the aortic root (annulus, sinus of Valsalva, sinotubular junction) and the ascending aorta, coronary ostial heights, and aortic angle. Agglomerative hierarchical clustering was performed separately on male and female datasets using R, with assessment of clusterability based on Hopkins statistics and agglomerative coefficient and the optimal number of clusters based on 30 previously validated indices (NbClust package). Multivariable logistic regression was conducted to assess the dependence of significant conduction disturbances (new left bundle branch block, advanced atrioventricular block) on cluster type.Results:Both male and female datasets were fairly clusterable (Hopkins statistics, 0.70 vs 0.68; agglomerative coefficient, 0.93 vs 0.93), with 3 and 2 as the optimal number of clusters, respectively. Of the 3 male clusters identified, the cluster with intermediate median values of aortic valve leaflet calcification loads and aortic root dimensions (M2) was associated with the greatest risk of conduction disturbances, compared to clusters with low (M1) and high (M3) median values of these variables (ORM2/M1=9.24,p=0.03; ORM2/M3=1.33,p=0.40; ORM3/M1=6.97,p=0.07). The risk of the M1 cluster was not statistically different from those of the female clusters (F1, F2; ORM1/F1=0.31,p=0.27; ORM1/F2=0.25,p=0.21), which were not different from each other (ORF1/F2=0.82,p=0.68).Conclusion:Machine learning of pre-TAVR CTAs can help identify subgroups of patients with similar or varying risks of TAVR-related conduction disturbances.

Circulation, Volume 148, Issue Suppl_1, Page A17865-A17865, November 6, 2023. Purpose:Catheter ablation is a popular treatment option for atrial fibrillation (AF), but AF recurrence is common. Currently, no marker exists to reliably predict the risk or location of recurrence (AF+). In this work, a multimodal imaging approach was employed to identify surface of interest (SOI) associated with recurrence using pre-ablation MRI and CT scans.Hypothesis:Shape of the left atrium (LA) plays a critical role in AF recurrence. The difference between AF+ and AF- may be identified on pre-ablation scan and may find potential sites for additional pre-emptive ablation. Method: Two representative template scans were selected from each group and all patients were registered to these respective templates to develop an atlas for each group. The two atlases were then co-registered, and the difference areas were obtained using a t-test with 500 permutations. The SOI was identified as the area that showed statistically significant (p

Circulation, Volume 148, Issue Suppl_1, Page A18397-A18397, November 6, 2023. Introduction:Thrombotic microvascular obstruction (MVO) poses a diagnostic challenge due to the lack of specific imaging techniques in clinical practice. This study introduces a novel ultrasound imaging method that utilizes gold nanoparticles (AuNPs) modified with the GPIIb/IIIa-targeting peptide Arg-Gly-Asp (RGD) to enhance the contrast of ultrasound imaging for microembolization.Methods:Targeted gold nanoparticles (RGD-AuNPs) and untargeted gold nanoparticles (GSH-AuNPs) were synthesized using the glutathione reduction method from chloroauric acid. A rat model of MVO was established by infusing microthrombi into the left hindlimb via the right femoral artery. The rats were randomly assigned to receive either RGD-AuNPs or GSH-AuNPs injected via an angiocatheter. Ultrasound imaging was performed on the left hindlimb for three hours at five-minute intervals, and the average video intensity of the images was measured. Histological staining and immunohistochemistry were performed to validate the co-localization of microthrombi and RGD-AuNPs.Results:In the RGD-AuNPs+MVO group, enhanced ultrasound signals were visible at 15 minutes and progressively increased over three hours. The average video intensity in this group was approximately three times higher than that in the GSH-AuNPs+MVO group (11.88±3.68 vs. 3.39±2.67, p0.05), or between the GSH-AuNPs control group and the RGD-AuNPs control group (3.50±2.09 vs. 2.95±2.18, p >0.05). Histological staining and immunohistochemistry confirmed the co-localization of microthrombi and RGD-AuNPs.Conclusions:Gold nanoparticles modified with the RGD peptide effectively enhance the signal of ultrasound imaging, enabling targeted imaging of thrombotic microvascular obstruction. This approach holds promise for improving the diagnosis and monitoring of MVO in clinical settings.

Circulation, Volume 148, Issue Suppl_1, Page A351-A351, November 6, 2023. Background:Effective use of information extracted from medical images has attracted attention for decision support in primary care of patients with cardiac arrest (CA).Hypothesis and Aims:This study aimed to predict the neurological prognosis of patients with cardiac arrest by quantitative imaging biomarkers (QIBs) extracted from acute CT brain images before admission using artificial intelligence.Methods:Eighty-six CA patients (good prognosis; Glasgow-Pittsburgh cerebral performance categories [CPC]=1 or 2 at 90 days after the CA : 32 patients, poor prognosis; CPC=3, 4, or 5 at 90 days after the CA : 54 patients) treated at three hospitals between 2017 and 2019 were retrospectively analyzed. None of the CA patients caused by trauma or brain damage were included in the database. The data were divided into training and test data, and the training data were used to select informative QIBs for classification between the good and poor neurological prognosis in this analysis.Results:Seven CA patients’ data were excluded from the study due to severe metal and bone artifacts broadly spreading on the brain image, and 1170 QIBs were extracted from whole brain and regional brain interest volumes on CT images of each patient. The QIBs were composed of first-order histogram and texture features and informative QIBs for the classification were selected by feature selection algorithms using the training dataset. The feature corresponding to the gray level having a maximum gradient in the image histogram from the brain region of interest on CT images showed the strongest significant difference between the good and poor neurological prognosis of the test data set with p=0.009 and AUC=0.775 (95% CI; 0.590-0.960).Conclusions:We have shown that QIB can be used to predict neurological prognosis in patients with CA. Because this is a pilot study for methodological development and there are limitations in sample size and outcomes, new studies on a larger number of patients are required.

Circulation, Volume 148, Issue Suppl_1, Page A17356-A17356, November 6, 2023. Background:A 24-year-old female with no medical history presented to the ED with chest pain and dyspnea. Vitals were notable for tachycardia to 120s. Physical examination was unremarkable.Clinical Course:Initial evaluation was notable for thrombocytopenia, NT-proBNP of 151 and high sensitivity troponin T of 18. Transthoracic echocardiogram (TTE) revealed a small pericardial effusion with tamponade physiology prompting urgent pericardiocentesis. Bloody pericardial fluid was drained and fluid studies were consistent with hemorrhagic effusion with no evidence of infection or malignancy on cytology. Surveillance TTEs showed rapid reaccumulation of pericardial fluid within 72 hours of the initial intervention. Urgent pericardial window with drain placement was performed and intraoperative transesophageal echocardiogram (TEE) revealed a right atrial (RA) mass not detected on prior TTE. Cardiac MRI confirmed the presence of a large (50 mm x 31 mm) immobile and heterogeneous mass in the superior aspect of the RA suggestive of a malignant etiology with invasion to the adjacent pericardium. Positron Emission Tomography (PET) scan demonstrated hypermetabolic activity concerning for malignancy with no evidence of mediastinal, hilar adenopathy, or distant disease. She underwent mini-sternotomy and biopsy with pathology suggestive of primary cardiac angiosarcoma. Due to the high-risk nature and location of the tumor, she was unable to undergo primary surgical resection. Neoadjuvant chemotherapy was initiated with plan for subsequent surgical reassessment.Conclusion:Workup of recurrent hemorrhagic pericardial effusions require a multimodal imaging approach.

Circulation, Volume 148, Issue Suppl_1, Page A15399-A15399, November 6, 2023. Introduction:Takotsubo syndrome (TTS) is characterized by transient left ventricular (LV) systolic dysfunction, triggered by physical or emotional stress, and associated with increased long-term cardiovascular morbidity. Cardiac iodine-123-meta-iodobenzylguanidine (mIBG) imaging has previously demonstrated sympathetic hyperactivity in the TTS subacute state which improves at follow-up during rest imaging. Cardiac neuronal dysfunction in response to stress has not been evaluated in recovered TTS.Hypothesis:Sympathetic hyperactivity, as measured by stress mIBG, is abnormal in TTS after recovery of LV ejection fraction (LVEF).Methods:To elicit a sympathetic challenge, women with history of TTS with recovered LVEF (n=19) and asymptomatic age- and sex-matched reference controls (n=10) underwent treadmill (6 minutes) with simultaneous mental-stress testing (public speaking with anger recall). mIBG (10 mCi) was injected during exercise, and planar and SPECT imaging were performed at 15 min (early) and 240 min (late), followed by Tc-99m tetrofosmin myocardial perfusion imaging. Early and late heart-to-mediastinal ratio (HMR) and washout rate (WR) corrected for background were calculated.Results:Median time from last TTS event was 23 months (range 4-56). Overall mean age was 60± 12 years, body mass index 25 ± 4kg/m2, resting LVEF 70 ± 7%, 41% hypertension and 0% diabetes with no difference between TTS and controls. TTS had higher resting (140 ± 22 vs 123 ± 19 mmHg, p=0.049) and peak (187 ± 17 vs 171 ± 15 mmHg, p= 0.018) systolic blood pressure. While the early HMR and WR were similar, the late HMR was significantly lower in the TTS group (Figure).Conclusions:Women with a history of TTS have lower late HMR but similar WR, suggesting neuronal dysfunction in response to sympathetic challenge persists long after recovery from TTS event. Further analysis of catecholamine levels and central nervous system neural pathways will explore the mechanism of dysregulation.

Circulation, Volume 148, Issue Suppl_1, Page A16516-A16516, November 6, 2023. INTRODUCTION:In hypertrophic cardiomyopathy (HCM), ventricular arrhythmia associates with severity of LVH and scar, and presence vs absence of a sarcomeric gene mutation (G+LVH+ vs G-LVH+). Also, ECG changes in subclinical HCM (G+LVH-) signal increased risk of phenotype progression.HYPOTHESES:ECG Imaging (ECGI) can detect: i) subtle electrophysiological (EP) abnormalities in subclinical HCM (pre-LVH). ii) EP abnormalities related to genetic status (G+ vs G-LVH+) and structural changes (late gadolinium enhancement [LGE], max. wall thickness [MWT]) in overt disease.METHODS:200 participant multicenter study: 70 G+LVH-, 51 G+LVH+, 53 G-LVH+ and 26 healthy volunteers (HV) underwent 12-lead ECG (to detect abnormal Q-waves, repolarization changes, LVH criteria) and CMR-ECGI computing epicardial unipolar electrograms (UEGs) to derive: activation time (AT), activation-recovery intervals (ARIc), spatial gradients (activation: GAT, repolarisation: GRT) and fractionation.RESULTS:Compared to HV, G+LVH- had prolongation of AT (40.3±7.3 vs 35.4±6.1 ms p=0.003) and steeper GRT(mean: 1.12±0.27 vs 1.00±0.23 ms/mm p=0.042, max: 11.7±2.8 vs 10.0±1.9 ms/mm p=0.005). AT was prolonged even in G+LVH- with a normal 12-lead ECG (p

Circulation, Volume 148, Issue Suppl_1, Page A296-A296, November 6, 2023. Aim:We compared head computed tomography (HCT) and diffusion-weighted magnetic resonance imaging (DW-MRI) findings before target temperature management (TTM) to predict neurological outcomes in out-of-hospital cardiac arrest survivors.Methods:Using prospectively collected data from a TTM registry, we included patients who underwent HCT and DW-MRI within 6 h of return of spontaneous circulation (ROSC). We examined the gray-to-white matter ratio (GWR) on HCT and apparent diffusion coefficient (ADC) values obtained through voxel-based analysis of DW-MRI. We analyzed the mean ADC value and the % voxels of ADC thresholds (percentage of voxels below ADC thresholds per total voxel) at 50-step intervals ranging from 200 to 1200 х 10-6mm/s, identifying thresholds that differentiate between good and poor neurological outcomes. Additionally, we analyzed the combination of pupillary light reflex (PLR) and neuron-specific enolase (NSE) values acquired at the same time points to predict the neurological outcomes. The primary outcome measure was the dichotomized cerebral performance category (CPC) at six months, defined as good (CPC 1-2) or poor (CPC 3-5).Results:Of 131 patients (26% female), 74 (57%) had poor outcomes. The time from ROSC to HCT and DW-MRI scans was 1.7h and 3.2h, respectively. The group with a good outcome had higher GWR (1.26 vs. 1.20) and mean ADC (787.10 vs. 697.49) values, but lower values in all ranges (250-1150) of ADC values (all P