Washout Rate Research Articles

Non-radiomics imaging (US-CEUS) features and clinical text features: correlation with microvascular invasion and tumor grading in hepatocellular carcinoma.

To predict microvascular invasion (MVI) status and tumor grading of hepatocellular carcinoma (HCC) by evaluating preoperative non-radiomics ultrasound and contrast-enhanced ultrasound (US-CEUS) features and determine the influences of MVI/tumor grading on the category of CEUS LI-RADS for HCC. A total of 506 HCC patients who underwent preoperative US-CEUS examinations from 8 hospitals between July 2020 and June 2023 were enrolled. According to the MVI status, all the patients were classified, and HCC differentiation was assessed by using Edmondson-Steiner (ES) grading: MVI-negative (M0) and low-grade ES (GI/II) (MN-L, n = 297) and MVI-positive (M1/M2) and/or high-grade ES (GIII/IV) (MP-H, n = 209). Stratified analysis was performed based on fibrosis stage and tumor size. The results proved that MN-L HCC was more frequently classified into the LR-5 category (p = 0.034), while MP-H HCC was more frequently classified into the LR-TIV (p = 0.010). The heterogeneously arterial phase hyperenhancement (APHE) is significantly correlated with MVI(+)/high grade-ES (p = 0.003). Compared with MN-L HCC, the onset of washout was earlier, washout rate was higher, and tumor-invasion border was larger (all p < 0.01) in MP-H HCC. In addition, fibrosis stage and tumor size significantly influenced the onset of washout and washout rate of HCC (all p < 0.01). The tumor-invasion border was only positively correlated with tumor size (p < 0.001) rather than fibrosis stage (p > 0.05). MVI status and tumor grading influence the classification of LR-5 and LR-TIV. Heterogeneous APHE, higher washout rate, earlier onset of washout (≤65s), larger tumor-invasion border (≥3mm) and higher alpha fetoprotein level indicate the presence of MVI and/or high-grade ES.

Assessment of high-risk gastroesophageal varices in cirrhotic patients using quantitative parameters from dual-source dual-energy CT.

To investigate the clinical value of dual-source dual-energy CT (dsDECT) quantitative parameters in evaluating hemodynamics and predicting high-risk gastroesophageal varices in cirrhotic patients. 98 consecutive patients were collected in this prospectively study and all patients underwent an abdominal triple-phase contrasted-enhanced examination with dsDECT. Iodine concentration (IC) and normalized iodine concentration (NIC) of the liver parenchyma, spleen parenchyma and aorta at different phases were recorded, and arterial iodine fraction (AIF), iodine washout rate (IWR), and extracellular volume (ECV) were calculated. Using upper gastrointestinal endoscopy as the reference standard, patients who met the inclusion and exclusion criteria were divided into groups with varices need treatment (VNT) and non-VNT. The clinical characteristics, traditional CT features and quantitative dsDECT parameters were compared between the VNT group and the non-VNT group using univariate analysis. The binary logistics analysis was used to build a model for diagnosing VNT. The receiver operating characteristic (ROC) curve was used for analysis and the DeLong test was used to compare different ROC curves. Finally, 57 patients were included in this study. Univariate analysis showed statistically significant differences in NIC of the liver at the portal venous phase (NIC-LPVP), IWR of the liver (IWR-L) and spleen volume between the VNT group and the non-VNT group (p < 0.05). The mixed-CT model was built by binary logistics analysis. The ROC curves of NIC-LPVP, IWR-L, spleen volume and the mixed-CT model were statistically significant (p < 0.05) for predicting VNT in cirrhotic patients, among which the area under the ROC curve of the mixed-CT model was the highest. Dual-source dual-energy CT has added clinical value in evaluating hepatic hemodynamics and diagnosing VNT in patients with liver cirrhosis.

Sympathetic nerve activity and response to physiological stress in Takotsubo syndrome.

The prevailing hypothesis posits that Takotsubo syndrome (TTS) is caused by massive sympathetic activation, yet supporting evidence remains inconsistent. The objectives of the present study were to determine whether sympathetic activity and reactivity are enhanced in the recovery phase of TTS, and to evaluate the effect of selective β1-receptor blockade on sympathetic reactivity. We conducted a case-control study that included 18 female patients with TTS and 13 age- and sex-matched controls. Muscle sympathetic nerve activity was measured through microneurography of the peroneal nerve at rest and during the cold pressor test. In the TTS group, recordings were repeated after randomisation to intravenous metoprolol or placebo. In 10 TTS patients, cardiac sympathetic activity was assessed using iodine123-metaiodobenzylguanidine scintigraphy. Blood samples were collected during hospitalisation. Microneurography was performed a median of 27.5days after patient admission. There were no significant differences in burst incidence, burst frequency, burst height or burst area between the TTS patients and the controls at rest, during stress or after administration of intravenous metoprolol. Iodine123-metaiodobenzylguanidine scintigraphy was performed a median of 12.5days after admission, revealing decreased early 1.54 ± 0.13 and late 1.40 ± 0.13 heart-to-mediastinum ratios, and an increased washout rate of 41.8 ± 12.1%. Catecholamine metabolites were comparable between the study groups. General sympathetic hyperactivity or hyperreactivityunlikelycontributesto TTS, as catecholamine levels and muscle sympathetic nerve activity at rest and during stress were similar between the TTS patients and the controls.As scintigraphy showed increased cardiac sympathetic activity, a pathological cardiac adrenergic response and vulnerability to sympathetic activationmay be crucial for the development of the syndrome.

Evaluations of a Cutaneous Wound Healing Model Using Oxygen Enhanced - Dynamic Contrast Enhanced Photoacoustic Imaging (OE-DCE PAI).

Preclinical models of cutaneous wound healing can be useful for improving clinical wound care. Oxygen Enhanced Photoacoustic imaging (OE PAI) can measure oxygenation, and Dynamic Contrast Enhanced (DCE) PAI can measure vascular perfusion. We investigated how a combined OE-DCE PAI protocol can measure vascular oxygenation and perfusion to a cutaneous healing model. We developed a cutaneous "punch" wound model and photographed the wounds to track healing for 9 days. We performed OE-DCE PAI on Day 0, 3, 6, and 9. OE PAI was performed with 21% O2 and 100% O2 breathing gases to measure oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), total hemoglobin (HbT), and oxygen saturation (%sO2), along with changes in these parameters caused by a change in breathing gas (ΔHb, ΔHbO2, ΔHbT, ΔsO2). To perform DCE PAI, indocyanine green (ICG) was administered intravenously while monitoring the PAI signal for 10min as the agent washed through the wound area, which was used to evaluate the wash-out rate. The average wound size was significantly smaller only by Day 6. For comparison, OE PAI measured a significant increase in HbO2, Hb, HbT, and %sO2 immediately after creating the wound, which significantly decreased by Day 3 and continued to decrease towards values for normal tissue by Day 9. The vascular wash-out rate significantly increased by Day 3, and continued to increase during the healing process. Notably, the wash-out rate can be assessed at a single PAI absorbance wavelength and by simply comparing signal amplitudes without advanced analysis, which may facilitate clinical translation. OE-DCE PAI can monitor significant changes in vascular perfusion and oxygenation prior to significant changes in cutaneous wound size. These results establish OE-DCE PAI as a tool for future pre-clinical wound healing studies and eventual clinical translation.

Comparison Between Prone SPECT-Based Semi-Quantitative Parameters and MBI-Based Semi-Quantitative Parameters in Patients with Locally Advanced Breast Cancer.

This study evaluates the semi-quantitative single-photon emission computed tomography (SPECT) parameters of prone SPECT using [99mTc]Tc-sestamibi and compares them with Molecular Breast Imaging (MBI)-derived semi-quantitative parameters for the potential use of response prediction in women with locally advanced breast cancer (LABC). Patients with proven LABC with a tumor ≥ 2cm on mammography and an indication for MBI using [99mTc]Tc-sestamibi were prospectively enrolled. All patients underwent a prone SPECT/CT at 5min (early exam) and an additional scan at 90min (delayed exam) after injection of 600MBq [99mTc]Tc-sestamibi to compose wash-out rates (WOR). All patients underwent MBI after early SPECT/CT. Volumes of interest of the primary tumor were drawn semi-automatically on early and delayed SPECT images. Semi-quantitative analysis included maximum and mean standardized uptake values (SUVmax,SUVmean,), functional tumor volume (FTVSPECT), total lesion mitochondrial uptake (TLMU), tumor-to-background ratios (TBRmaxand TBRmean), WOR and coefficient of variation (COVSPECT). Subsequently, the FTVSPECT,TBRSPECTand COVSPECTwere compared to FTVMBI,TBRMBIand COVMBI. Eighteen patients were included. Early SUVmax, and TBRmax showed significantly higher interquartile range (IQR) compared to SUVmean and TBRmean, respectively 2.22 (2.33) g/mL, 6.86 (8.69), 1.29 (1.39) g/mL and 3.99 (5.07) (median (IQR), p < 0.05). WOR showed a large IQR (62.28), indicating that there is WOR variation among the LABC patients. FTV showed no difference between MBI and early SPECT semi-quantitative parameter (p = 0.46). In LABC patients it is feasible to obtain semi-quantitative parameters from prone SPECT/CT. The FTV derived from early prone SPECT/CT is comparable with MBI-based FTV. Studies with comprehensive clinical parameters are needed to establish the clinical relevance of these semi-quantitative parameters, including WOR, for response prediction before its use in clinical routine.

Ionogels in Aqueous Media: From Conductometric Probing of the Ionic Liquid Washout to the Design of More Stable Materials

Although the most promising applications of ionogels require their contact with aqueous media, few data are available on the stability of ionogels upon exposure to water. In this paper, a simple, easy-to-setup and precise method is presented, which was developed based on the continuous conductivity measurements of an aqueous phase, to study the washout of imidazolium ionic liquids (IL) from various silica-based ionogels immersed in water. The accuracy of the method was verified using HPLC, its reproducibility was confirmed, and its systematic errors were estimated. The experimental data show the rapid and almost complete (&gt;90% in 5 h) washout of the hydrophilic IL (1-butyl-3-methylimidazolium dicyanamide) from the TMOS-derived silica ionogel. To lower the rate and degree of washout, several approaches were analysed, including decreasing IL content in ionogels, using ionogels in a monolithic form instead of a powder, constructing ionogels by gelation of silica in an ionic liquid, ageing ionogels after sol–gel synthesis and constructing ionogels from both hydrophobic IL and hydrophobic silica. All these approaches inhibited IL washout; the lowest level of washout achieved was ~14% in 24 h. Insights into the ionogels’ structure and composition, using complementary methods (XRD, TGA, FTIR, SEM, NMR and nitrogen adsorption), revealed the washout mechanism, which was shown to be governed by three main processes: the diffusion of (1) IL and (2) water, and (3) IL dissolution in water. Washout was shown to follow pseudo-second-order kinetics, with the kinetic constants being in the range of 0.007–0.154 mol−1·s−1.

The activation of cardiac sympathetic nervous system in the non-culprit lesion is a strong prognostic predictor in patients with acute myocardial infarction

Abstract Background The activation of cardiac sympathetic nervous system is associated with poor prognosis in patients with acute myocardial infarction (AMI). However, it remains to be determined whether regional assessment of cardiac sympathetic nerve activity (CSNA) in the culprit and non-culprit lesion of the cardiac MIBG SPECT imaging could have prognostic value in patients with AMI. Purpose The purpose of this study is to investigate the prognostic impact of regional CSNA in patients with AMI. Methods We prospectively enrolled 122 patients with AMI who visited our emergency department and underwent primary percutaneous coronary intervention. The late heart-to-mediastinum ratio (HMR) and washout rate (WR) was calculated to assess CSNA in the whole heart from planar images of in the cardiac MIBG imaging. The MIBG SPECT image parameters were calculated for each coronary artery, and the average WR in the culprit and non-culprit lesion were evaluated to assess the regional status of CSNA in patients with AMI. Abnormal WR in planar image was defined as 34% or more, as previously reported. The cut-off value of late HMR in planar image, WR in the culprit and non-culprit lesions were determined by ROC analysis. The primary endpoint was major adverse cardiac event (MACE) including all cause death, myocardial infarction, hospitalization for heart failure and target lesion revascularization. Results During a mean follow-up period of 3.1±1.8 years, 25 of 122 patients underwent MACE. The late HMR (p=0.004), WR in planar image (p=0.002), WR in the culprit lesion (p=0.023), and WR in the non-culprit lesion (p&amp;lt;0.001) were significantly associated with MACE at univariate Cox proportional hazard analysis. The increased WR in the non-culprit lesion (defined as 28.3% or more: AUC 0.697 [0.576-0.817]) was significantly independently associated with MACE (hazard ratio: 4.36 [1.45-13.11], p=0.009) even adjusted by late HMR, WR in planar image or WR in the culprit lesion, while decreased HMR, abnormal WR in planar image and increased WR in the culprit lesion showed no significant association with MACE in the multivariate model with WR in the non-culprit lesion. Kaplan-Meier analysis revealed that patients with increased WR in the non-culprit lesion had significantly higher risk for MACE than those without increased WR (45% vs 11% p&amp;lt;0.001). Conclusion(s) The activation of cardiac sympathetic nervous system in the non-culprit lesion is particularly associated with poor prognosis in patients with acute myocardial infarction.MACE risk by WR in non-culprit lesion

Usefulness of visual classification for cardiac pathophysiology using count-washout rate map in iodine-123-beta-methyl-P-iodophenyl-pentadecanoic acid scintigraphy

Abstract Background Myocardial washout rate (WR) analysis of radiopharmaceuticals is utilized in nuclear cardiology to evaluate the clinical pathophysiology of the heart. WR is defined as the ratio of the difference between the counts in the early image and time-decay-corrected delayed image divided by the former. The myocardial WR of iodine-123-β-methyl iodophenyl-pentadecanoic acid (BMIPP) is an indicator of myocardial lipolysis, and a decreased WR (&amp;lt;10%) of BMIPP is one of the diagnostic criteria for triglyceride deposit cardiomyovasculopathy (TGCV). However, decreased BMIPP uptake in the early images, as in old myocardial infarction (OMI), would also cause a markedly decreased WR. Since the distinction between these clinical conditions cannot be made based on WR alone, simultaneous evaluation of the counts in the early image and WR is needed to properly understand the cardiac pathophysiology. Purpose To differentiate between TGCV and non-TGCV with OMI, both of which show decreased BMIPP WR, a new Count-WR Map (CWRM) method was evaluated. The purpose is to visually and easily distinguish between the two conditions using CWRM. Methods We introduced a CWRM consisting of two axes: counting in the early image, and WR. The count window was set to a maximum of the mean plus two standard deviations and a minimum of 50 counts, and the WR window was set to a maximum of 30 % and a minimum of -20%. CWRM was visually evaluated as normal, TGCV, non-TGCV with OMI, or TGCV with OMI. Results In normal cases, sufficient counts were observed in the early images, and WR did not decrease; CWRM showed light blue. In TGCV, sufficient counts were observed in the early image, but WRs markedly decreased; CWRM showed even orange. In non-TGCV with OMI, regions with decreased and preserved counts coexisted; CWRM showed light blue in the normal and black in the OMI region. In TGCV with OMI, CWRM showed orange in the TGCV myocardium and black in the OMI region (figure). Conclusions CWRM is useful for visually and easily differentiating TGCV from non-TGCV with OMI. CWRM can be applied to other cardiovascular diseases with count and WR variations for visual classification.

Cardiac sympathetic innervation, assessed with 123I-MIBG SPECT, predicts left ventricular function improvement in patients with newly diagnosed dilated cardiomyopathy

Abstract Introduction Beta-blockers (BB) are commonly prescribed medications for heart failure (HF) due to their ability to counteract the increased sympathetic nervous system (SNS) activity seen in HF, resulting in downregulation and desensitization of β-receptors. In patients with dilated cardiomyopathy (DCM), the introduction of BB therapy can lead to left ventricular ejection fraction (LVEF) improvement in 30-50% of cases. Single-photon emission computed tomography (SPECT) with 123I-meta-iodobenzylguanidine (MIBG) is a useful tool for assessing cardiac SNS activity. Healthy individuals typically exhibit high SPECT-MIBG uptake and low washout rate (WR) due to normal β-receptor levels and low norepinephrine (NE) levels, respectively (Fig 1A). While better SPECT-MIBG results have been associated with LVEF improvement in the general HF population, less data is available for DCM patients. Purpose This study aimed to evaluate the predictive value of MIBG-SPECT for LVEF improvement in newly diagnosed DCM patients. Methods Twenty-one DCM patients (mean age 47 ± 10 years, 90% male, baseline LVEF 29.5 ± 8.7%, left ventricular end-diastolic volume (LVEDV) 114 ± 36 ml/m2) with stable HF symptoms (NYHA class 1.8 ± 0.6) and newly diagnosed DCM underwent baseline MIBG-SPECT and echocardiography. HF therapy was initiated and up-titrated, and echocardiography was repeated at 6 months. Semi-quantitative parameters from MIBG-SPECT, including the MIBG uptake ratio from the heart and mediastinum (H/M) at 15 minutes (-15) and 4 hours (-4), as well as the WR [WR = (H/M-15 - H/M-4) / H/M-15], were evaluated. Patients were stratified based on median WR - 8.79 (IQR 5.17-12.90). Results After 6-months of HF therapy up-titration, 18 patients improved LVEF, and the mean LVEF increase was 7.7 ± 10.4%. Although, patients with WR &amp;gt; median did not differ in terms of baseline LVEF (30.2 ± 7.0 vs. 27.7 ± 9.6, p=0.52), they had worse LVEF at 6 months (32.0 ± 11.0 vs. 40.6 ± 9.2%, p=0.04). Moreover, WR at baseline strongly correlated with 6-month LVEF (R=-0.51, p=0.01) and was a significant predictor of 6-month LVEF (β=-0.55 ± 0.19, p=0.009). Moreover, WR could successfully predict LVEF improvement ≥ 10% (OR 1.27 [95%CI 1.01-1.61], p=0.03; AUC 0.82 [95%CI 0.63-0.99], p&amp;lt;0.001) with a cut-off point of 8.0 (sensitivity 88%, specificity 77%) (Fig 1B). Conclusion Most DCM patients demonstrated LVEF improvement during 6 months of HF therapy up-titration. Baseline WR from MIBG-SPECT was found to be a reliable predictor of significant LVEF improvement in this patient population.Fig1.A-SPECT-MIBG results. B-ROC curve.

Improvement of myocardial lipolysis in iodine-123-beta-methyl-P-iodophenyl-pentadecanoic acid scintigraphy in patients with idiopathic triglyceride deposit cardiomyovasculopathy treated with Tricaprin

Abstract Background Triglyceride deposit cardiomyovasculopathy (TGCV) is a rare intractable cardiovascular disorder (Orphanet ORPHAcode: 565612) in which defective intracellular lipolysis results in heart failure and coronary artery disease. Myocardial scintigraphy with iodine-123-β-methyl-P-iodophenyl-pentadecanoic acid (BMIPP) is useful for evaluating myocardial TG metabolism and its washout rate (WR) reflects myocardial lipolysis. A decreased WR (&amp;lt;10%) of BMIPP is one of the diagnostic criteria for TGCV. CNT-01, the active ingredient of which is tricaprin, a medium-chain triglyceride, has the potential to facilitate myocardial lipolysis in a mouse model. However, the effects of CNT-01 (tricaprin) on BMIPP scintigraphy in patients with TGCV remain unclear. Purpose To evaluate the effects of CNT-01 on BMIPP-WR in patients with TGCV. Methods An investigator-initiated, randomized, double-blind exploratory trial (Phase IIa) was conducted. Ten patients with idiopathic TGCV in our hospital were enrolled and orally administered 1.5 g/day of CNT-01 or placebo for 8 weeks. The endpoint was the delta WR on BMIPP scintigraphy. All the participants underwent BMIPP scintigraphy after overnight fasting. Following the protocol recommended by the Japanese Society of Nuclear Cardiology, 111 MBq of BMIPP was intravenously injected at rest after fasting for ≥ 12 h. Early and delayed images were obtained after 20 and 180–210 min, respectively. BMIPP scintigraphy at baseline and 8-week was performed using the same SPECT apparatus. WR is defined as the ratio of the difference between the counts in the early image and time-decay-corrected delayed image divided by the former. We used a recently proposed algorithm for calculating the WR based on the total count and analyzed the WRs (Ann Nucl Cardiol. 2023;9(1):19-25). Results A total of 5 patients were assigned to placebo and 5 patients were assigned to CNT-01. During the protocol, delta BMIPP-WRs were -6.18 ± 4.43 and 5.44 ± 2.57 % (95% confidence intervals, -12.33 to -0.03 and 1.88 to 9.00) in the placebo and CNT-01 groups, respectively. The baseline-adjusted difference in delta BMIPP-WR between the two groups was significant (p=0.005) (Picture). No significant changes were observed in clinical parameters. Conclusion This study demonstrated that CNT-01 improved myocardial lipolysis in patients with TGCV as measured by BMIPP scintigraphy.

Impact of paroxysmal atrial fibrillation ablation on cardiac sympathetic nervous system: a prospective stratified randomized comparative study in patients with and without heart failure

Abstract Background Catheter ablation of atrial fibrillation (AF) might influence the cardiac sympathetic nervous system (CSNS). We sought to investigate the impact of AF ablation with 2nd generation cryoballoon catheter (CB) and contact force sensing radiofrequency ablation catheter (RF) on CSNS and the association of this effect with early AF recurrence in patients with and without heart failure (HF), using cardiac iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy. Methods and Results One hundred sixty-five paroxysmal AF patients who were scheduled for ablation were enrolled. All patients were categorized into two groups: one with HF (n=31), defined as left ventricular ejection fraction ≤ 40% or previous history of hospitalization for worsening HF, and the other without HF (n=134). They were then randomly assigned to CB (17 patients with HF and 68 without HF) or RF (14 with HF and 66 without HF). MIBG scintigraphy was performed at baseline and 3 months post-ablation and the washout rate (WR) was measured. There were no significant changes in WR from baseline to 3 months after RF and CB ablation (28.7±18.6% to 27.9±16.7% in RF and 29.4±16.7% to 30.5±16.4% in CB). WR decreased more in patients with HF at 3 months after ablation than without HF, while WR significantly increased in patients without HF and there was a significant interaction in WR change between with or without HF (interaction p&amp;lt;0.001). WR change from the baseline to 3 months after ablation (dWR) was not significantly different between CB and RF, irrespectively of the HF presence. In the blanking period of 3 months after ablation, early AF recurrence (EAR) was observed in 37 (22%) patients with no antiarrhythmic drugs (17(21%) patients in RF and 20(24%) in CB). dWR was significantly greater in patients with than without EAR (4.0±14.1% vs -0.9±11.0%, p=0.027). Higher dWR (≥ 6.9% (AUC 0.644, 95%CI [0.535-0.753]) by ROC curve analysis) was independently associated with EAR (adjusted odds ratio = 4.15, 95%CI [1.87-9.22], p&amp;lt;0.001, adjusted for age, sex, and left atrial diameter). Conclusions Irrespectively of CB and RF, AF ablation might reduce adrenergic tone in patients with HF, while it might induce more adrenergic tone in patients without HF. Excessive adrenergic tone might be associated with early AF recurrence.WR changes before and after ablationdWR in patients with or without HF

Remote ischemic peri-conditioning suppressed cardiac sympathetic nerve activity especially in the non-culprit lesion in patients with acute myocardial infarction

Abstract Background Remote ischemic periconditioning (RIPC) has demonstrated cardioprotective effects and improved clinical outcomes as an adjunct to emergent percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). However, it remains to be elucidated whether RIPC affects the cardiac sympathetic nerve activity in patients with AMI. Purpose The purpose of this study is to investigate the effect of RIPC on cardiac sympathetic nerve activity (CSNA) in the culprit and non-culprit lesion respectively in patients with AMI. Methods We randomly assigned 157 patients with suspected AMI undergoing emergent PCI to receive transient limb ischemia (by inflating a cuff at 200 mmHg for 4×5 minutes: RIPC group, n=77) or no procedure (control group, n=80). After excluding inappropriate patients such as those with other diagnosis than AMI, we analyzed 122 patients (62 patients in RIPC and 60 in control group). CSNA was assessed in the culprit and non-culprit lesion respectively by the cardiac MIBG SPECT imaging. Results Patients in RIPC and control group had similar demographic and clinical characteristics at baseline. Patients in RIPC group tended to show higher late uptake only in the non-culprit lesion at discharge. At 1 year after discharge, patients in RIPC group demonstrated significantly higher late uptake (p=0.021) and lower washout rate (p=0.013) than those in control group in the non-culprit lesion. Regarding the culprit lesion, only washout rate tended to be lower in RIPC group at 1 year after discharge. Conclusion(s): Remote ischemic peri-conditioning showed suppressive effect on cardiac sympathetic nerve activity especially in the non-culprit lesion in patients with acute myocardial infarction.SPECT parameters in RIPC and control

The Utility of Baseline Characteristics and [123I]MIBG Cardiac Adrenergic System Scintigraphy in Qualifying Patients with Post-Infarction Heart Failure for Implantable Cardioverter-Defibrillator (ICD) Placement.

Background: Post-infarction heart failure with reduced ejection fraction (HFrEF) patients often face persistent risks of sudden cardiac arrest leading to sudden cardiac death. While implanting a cardioverter-defibrillator (ICD) can enhance prognosis, complications and costs limit its widespread use. Current patient qualification criteria, relying on imperfect parameters, require refinement. The impairment of the cardiac adrenergic system in heart failure is associated with ventricular arrhythmias. The goal of the study was to assess the utility of cardiac adrenergic system scintigraphy in qualifying patients for ICD placement. Methods: In this prospective study of 85 post-infarction HFrEF patients at a single center, clinical assessments, laboratory tests, echocardiography, [123I]MIBG scintigraphy, and ICD implantation were performed. Scintigraphy involved planar chest images and evaluating the heart-to-mediastinum ratio (H/M) and washout rate (WO). SPECT imaging assessed [123I]MIBG uptake in 17 left ventricular segments to calculate the summed difference score (SDS). Results: During a median of 4-year follow-up, 22% of patients experienced appropriate ICD interventions, and 25% of patients died or underwent heart transplantation. The mean values of analyzed parameters did not significantly differ between groups. In the univariate analysis, younger age and moderately impaired left ventricular ejection fraction (LVEF) were correlated with more frequent ICD interventions. In comparison, older age and elevated NT-proBNP levels were associated with death or heart transplantation. Additionally, the univariate analysis identified SDS-15' as a prognostic factor for death/heart transplant. The multivariate analysis identified predictors for ICD interventions, including younger age, an EF of 30% or greater, and a larger left ventricular end-diastolic diameter. In contrast, older age and an LVEF of less than 25% were significant predictors of death or heart transplantation. Conclusions: Scintigraphic parameters did not effectively predict ICD interventions or death/heart transplantation, though the summed difference score demonstrated potential as a prognostic factor. Younger age with moderately impaired EF correlated with frequent ICD interventions, while in older age, EF < 25% predicted death or transplantation. Further investigation is needed for patients with borderline EF values.

Remote ischemic periconditioning suppresses cardiac sympathetic activation in acute myocardial infarction: a randomized controlled trial.

Remote ischemic periconditioning (RIPC) has demonstrated cardioprotective effects and improved clinical outcomes as an adjunct to emergent percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). However, whether RIPC affects the cardiac sympathetic nerve activity in patients with STEMI remains unclear. This study investigated the effects of RIPC on cardiac sympathetic nerve activity in patients with STEMI. We prospectively assigned patients with STEMI who underwent emergent PCI to receive RIPC or no procedure (control group) upon arrival at the cardiac catheterization laboratory. The primary endpoint was cardiac sympathetic nerve activity assessed through the washout rate (WR) in cardiac 123I-metaiodobenzylguanidine (123I-MIBG) imaging. Patients in the RIPC (n = 62) and control (n = 60) groups had similar demographic and clinical characteristics at baseline. Multivariable linear regression models revealed that the culprit lesion of the left anterior descending artery and hemoglobin level were significantly and independently associated with WR at discharge. WRs of the groups differed insignificantly at discharge. However, the RIPC group (n = 49) showed significantly lower WR than the control group (n = 47) at 1year after discharge (p = 0.027). In the single-photon emission computed tomography analysis at 1year after discharge, the RIPC group demonstrated significantly higher late uptake (p = 0.021) and lower WR (p = 0.013) in the nonculprit lesion, with a non-significant decrease in WR for the culprit lesion. RIPC can suppress augmented cardiac sympathetic nerve activity in patients with STEMI, particularly in nonculprit lesions.

Quantitative Multi-Parametric MRI of the Prostate Reveals Racial Differences

Purpose: This study investigates whether quantitative MRI and histology of the prostate reveal differences between races, specifically African Americans (AAs) and Caucasian Americans (CAs), that can affect diagnosis. Materials and Methods: Patients (98 CAs, 47 AAs) with known or suspected prostate cancer (PCa) underwent 3T MRI (T2W, DWI, and DCE-MRI) prior to biopsy or prostatectomy. Quantitative mpMRI metrics: ADC, T2, and DCE empirical mathematical model parameters were calculated. Results: AAs had a greater percentage of higher Gleason-grade lesions compared to CAs. There were no significant differences in the quantitative ADC and T2 values between AAs and CAs. The cancer signal enhancement rate (α) on DCE-MRI was significantly higher for AAs compared to CAs (AAs: 13.3 ± 9.3 vs. CAs: 6.1 ± 4.7 s−1, p &lt; 0.001). The DCE signal washout rate (β) was significantly lower in benign tissue of AAs (AAs: 0.01 ± 0.09 s−1 vs. CAs: 0.07 ± 0.07 s−1, p &lt; 0.001) and significantly elevated in cancer tissue in AAs (AAs: 0.12 ± 0.07 s−1 vs. CAs: 0.07 ± 0.08 s−1, p = 0.02). DCE significantly improves the differentiation of PCa from benign in AAs (α: 52%, β: 62% more effective in AAs compared to CAs). Histologic analysis showed cancers have a greater proportion (p = 0.04) of epithelium (50.9 ± 12.3 vs. 44.7 ± 12.8%) and lower lumen (10.5 ± 6.9 vs. 16.2 ± 6.8%) in CAs compared to AAs. Conclusions: This study shows that AAs have different quantitative DCE-MRI values for benign prostate and prostate cancer and different histologic makeup in PCa compared to CAs. Quantitative DCE-MRI can significantly improve the performance of MRI for PCa diagnosis in African Americans but is much less effective for Caucasian Americans.

A new approach to modeling transdermal ethanol kinetics.

Measurement of ethanol above the skin surface (supradermal) is used to monitor blood alcohol concentrations (BAC) in both legal and consumer settings. Previously, the relationship between supradermal alcohol concentration (SAC) and BAC was described using partial and ordinary differential equations (PDE model: J. Appl. Physiol. 100: 649-55, 2006). Using a range of BAC profiles by varying absorption times and peak concentrations, the PDE model accurately predicted experimental measures of SAC. Recently, other mathematical models have relied on the PDE model. This paper proposes a new approach to modeling transdermal ethanol kinetics using a mass transfer coefficient and only ordinary differential equations (ODE model). Using a range of BAC profiles, the ODE model performed very similarly to the PDE model. The ODE model had slightly slower washout rates and slightly slower times to peak SAC and to zero SAC. Similar to the PDE model, a sensitivity analysis on the ODE model showed changes in solubility and diffusivity within the stratum corneum, stratum corneum thickness, and the volume of gas above the skin affected model performance. This new model will streamline integration into larger physiologic models, reduce computation time, and decrease the time to transform skin alcohol measurements to blood alcohol concentrations.

Enhanced Differentiation of Amiodarone-Induced Thyrotoxicosis Types Using Semi-Quantitative 99mTc-MIBI Uptake Analysis: A Pilot Study.

BACKGROUND Technetium (99mTc)-labelled Methoxy-2-Isobutylisonitrile (MIBI) is a diagnostic lipophilic cationic radiotracer used to evaluate the cardiac, breast, thyroid, and parathyroid pathology. This study aimed to evaluate the role of MIBI combined with Tc-99m pertechnetate thyroid scintigraphy, thyroid ultrasonography, and measurement of thyrotropin, thyroid hormones, and autoantibodies to subtype amiodarone-induced thyrotoxicosis (AIT) and the contribution of semi-quantitative analysis of MIBI uptake. MATERIAL AND METHODS This cross-sectional study included 36 patients with AIT who underwent thyrotropin, thyroid hormone, and autoantibody analysis using chemiluminescent method, ultrasonography, pertechnetate, and MIBI thyroid scintigraphy with semi-quantitative uptake, including calculation of the target-to-background ratio (TBR) with 2 different background regions. The MIBI washout rate (WR) was analyzed in all groups. Statistical analysis was performed using descriptive statistics, correlations, and the receiver operating characteristic curve - area under the curve (ROC-AUC). The results were compared with the control group. RESULTS Based on visual and semi-quantitative analyses, patients were successfully categorized into AIT groups (AIT-1, AIT-2 and AIT-3) but the latter method enabled better differentiation of MIBI uptake between all groups. Additionally, ROC-AUC analysis determined cutoff values which enabled discerning between AIT-1 and AIT-2 groups, and AIT-1 and AIT-3 groups. WR showed no significant difference between all AIT groups and controls (P>0.05). CONCLUSIONS Visual MIBI analysis enabled differentiation between AIT-1 and 2 groups, but the method was substantially improved with semi-quantitative analysis, especially in defining AIT-3 group. However, multicenter collaboration with larger studies is needed to standardize the method and obtain more accurate and consistent results.

Quantitative and qualitative analysis of contrast-enhanced ultrasound for differentiating benign and malignant superficial enlarged lymph nodes.

In many clinical situations, it is critical to exclude or identify abnormally lymph nodes (LNs). The nature of superficial abnormally LNs is closely related to the stage, treatment, and prognosis of the disease. Ultrasound (US) is an important method for examining superficial LNs due to its cheap and safe characteristics. However, it is still difficult to determine the nature of some LNs with overlapping benign and malignant features in images. Contrast-enhanced ultrasound (CEUS) can be used to evaluate the microperfusion status of tissues in real time, and it can improve diagnostic accuracy to a certain extent. Therefore, in this study, we will analyze the correlation between CEUS quantitative parameters and benign and malignant superficial abnormally LNs, to evaluate the efficacy and value of CEUS in distinguishing benign and malignant superficial LNs. This study retrospectively analyzed 120 patients of abnormal LNs who underwent US and CEUS at the China-Japan Union Hospital of Jilin University from December 2020 to August 2023. All 120 cases of abnormal LNs underwent US-guided coarse needle biopsy, and accurate pathological results were obtained, along with complete US and CEUS images. According to the pathological results, LNs were divided into benign and malignant groups, and the qualitative and quantitative parameters of US and CEUS between the two groups were analyzed. The cutoff value is determined by the receiver operating characteristic (ROC) curve of the subjects, and sensitivity, specificity, and accuracy are applied to evaluate the ability of the cutoff value to distinguish between the two groups. There were a total of 120 LNs, including 36 in the benign group and 84 in the malignant group. The results showed that malignant LNs were usually characterized by the disappearance of lymphatic hilum, round ness index (L/T) <2, irregular morphology, and the manifestation of uneven perfusion (P<0.05). The differences in the quantitative parameters peak enhancement (PE), rise time (RT), time to peak (TTP), wash-in rate (WIR), and wash-out rate (WOR) were statistically significant (P<0.05). The result showed that RT and TTP in the malignant LNs were higher than those in the benign LNs, while the PE, WIR, and WOR were lower. A comparison of the ∆ values showed that the differences in ∆PE, ∆WIR, and ∆fall time (FT) were statistically significant (P<0.05), Among them, the ∆PE and ∆WIR of malignant LNs were higher than those of benign LNs, while the ∆FT was lower than that of benign LNs. Quantitative analysis of CEUS features is valuable in the diagnosis of benign and malignant LNs, and US combined with CEUS helps to improve the accuracy of identifying the nature of LNs.

Evaluation of damage discrimination in dopaminergic neurons using dopamine transporter PET tracer [18F]FECNT-d4

BackgroundParkinson’s disease (PD) is a prevalent neurodegenerative disorder worldwide, diagnosed based on classic symptoms like motor dysfunction and cognitive impairments. With the development of various radioactive ligands, positron emission tomography (PET) imaging combined with specific radiolabelling probes has proven to be effective in aiding clinical PD diagnosis. Among these probes, 2β-Carbomethoxy-3β-(4-chlorophenyl)-8-(2-[18F]-fluoroethyl) nortropane ([18F]FECNT) has been utilized as a PET tracer to image dopamine transporter (DAT) integrity in striatal presynaptic dopaminergic terminals. However, the presence of brain-penetrant radioactive metabolites produced by [18F]FECNT may impact the accuracy of PET imaging. In previous research, we developed 2β-Carbomethoxy-3β-(4-chlorophenyl)-8-(2-[18F]-fluoroethyl-1,1,2,2-d4) nortropane ([18F]FECNT-d4), a deuterated derivative with enhanced stability in plasma and the striatum, along with a slower washout rate. In this study, we further investigated the potential of [18F]FECNT-d4 to detect dopaminergic neuron degeneration in Parkinson’s disease. This involved PET imaging in unilaterally-lesioned PD model rats and in vitro autoradiography conducted on postmortem brain sections.ResultsPET images revealed reduced specific uptake in the ipsilateral striatum of rats stereotactically injected with 6-hydroxydopamine hydrochloride (6-OHDA). Compared to the sham group, the ratio of standardized uptake value (SUV) in the ipsilateral to contralateral striatum decreased by 13%, 23%, and 63% in the mild, moderate, and severe lesioned groups, respectively. Dopaminergic denervation observed in PET imaging was further supported by behavioral assessments, immunostaining, and monoamine concentration tests. Moreover, the microPET results exhibited positive correlations with these measurements, except for the apomorphine-induced rotational behavior test, which showed a negative correlation. Additionally, [18F]FECNT-d4 uptake was approximately 40% lower in the postmortem striatal sections of a PD patient compared to a healthy subject. Furthermore, estimated human dosimetry (effective dose equivalent: 5.06 E-03 mSv/MBq), extrapolated from rat biodistribution data, remained below the current Food and Drug Administration limit for radiation exposure.ConclusionOur findings demonstrate that [18F]FECNT-d4 accurately estimates levels of dopaminergic neuron degeneration in the 6-OHDA-induced PD rat model and effectively distinguishes between PD patients and healthy individuals. This highly sensitive and safe PET probe holds promising potential for clinical application in the diagnosis and monitoring of Parkinson’s disease.

Evaluation of multiparametric MRI differentiating pleomorphic adenoma from schwannoma in parapharyngeal space.

This study aimed to investigate whether multiparametric magnetic resonance imaging (MRI) including dynamic contrast-enhanced (DCE) and diffusion weighted (DW) MRI can differentiate pleomorphic adenoma (PA) from schwannoma in the parapharyngeal space. Forty-six patients with pathologically proven PAs and 47 schwannomas in the parapharyngeal space were enrolled. All patients underwent conventional MRI, and DW-MRI and DCE-MRI were performed in 30 and 33 patients, respectively. Fisher's exact, Mann-Whitney-U tests and Independent samples t-test were used to compare variables between PAs and schwannomas. Multivariate logistic regression analysis was used to examine the diagnostic performance of MRI parameters. The PAs usually show lobulation sign, posterior displacement of ICA and attached to the parotid gland deep leaf, while bird beak configuration, anterior displacement of ICA and involvement of foramen jugular were more commonly seen in the schwannomas(all p < 0.001). The washout rate of PAs was found to be higher than that of schwannomas (p = 0.035), whereas no significance was found in the other DCE-MRI parameters and in ADCs(p > 0.05). Using a combination of conventional MRI features including lobulation sign, bird beak configuration, direction of internal carotid artery(ICA) displacement and attached to the parotid gland in multivariate logistic regression analysis, sensitivity, specificity, and accuracy in differential diagnosis of PAs and schwannomas were 97.8%, 91.5% and 94.6%, respectively. Conventional MRI can effectively differentiate PAs from schwannomas in the parapharyngeal space with a high diagnostic accuracy. The DCE-MRI and DWI have limited added diagnostic value to conventional MRI in the differential diagnosis.