International Journal of Biomedical Imaging最新文献

{"title":"Assessing Predictive Ability of Dynamic Time Warping Functional Connectivity for ASD Classification.","authors":"Christopher Liu, Juanjuan Fan, Barbara Bailey, Ralph-Axel Müller, Annika Linke","doi":"10.1155/2023/8512461","DOIUrl":"10.1155/2023/8512461","url":null,"abstract":"<p><p>Functional connectivity MRI (fcMRI) is a technique used to study the functional connectedness of distinct regions of the brain by measuring the temporal correlation between their blood oxygen level-dependent (BOLD) signals. fcMRI is typically measured with the Pearson correlation (PC), which assumes that there is no lag between time series. Dynamic time warping (DTW) is an alternative measure of similarity between time series that is robust to such time lags. We used PC fcMRI data and DTW fcMRI data as predictors in machine learning models for classifying autism spectrum disorder (ASD). When combined with dimension reduction techniques, such as principal component analysis, functional connectivity estimated with DTW showed greater predictive ability than functional connectivity estimated with PC. Our results suggest that DTW fcMRI can be a suitable alternative measure that may be characterizing fcMRI in a different, but complementary, way to PC fcMRI that is worth continued investigation. In studying different variants of cross validation (CV), our results suggest that, when it is necessary to tune model hyperparameters and assess model performance at the same time, a <i>K</i>-fold CV nested within leave-one-out CV may be a competitive contender in terms of performance and computational speed, especially when sample size is not large.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10620025/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71427758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of Esophageal Varices in Viral Hepatitis C Cirrhosis: Performance of Combined Ultrasonography and Clinical Predictors.","authors":"Puwitch Charoenchue,&nbsp;Wittanee Na Chiangmai,&nbsp;Amonlaya Amantakul,&nbsp;Wasuwit Wanchaitanawong,&nbsp;Taned Chitapanarux,&nbsp;Suwalee Pojchamarnwiputh","doi":"10.1155/2023/7938732","DOIUrl":"https://doi.org/10.1155/2023/7938732","url":null,"abstract":"<p><strong>Objectives: </strong>This study is aimed at evaluating the diagnostic performance of clinical predictors and the Doppler ultrasonography in predicting esophageal varices (EV) in patients with hepatitis C-related cirrhosis and exploring the practical predictors of EV.</p><p><strong>Methods: </strong>We conducted a prospective study from July 2020 to January 2021, enrolling 65 patients with mild hepatitis C-related cirrhosis. We obtained clinical data and performed grayscale and the Doppler ultrasound to explore the predictors of EV. Esophagogastroduodenoscopy (EGD) was performed as the reference test by the gastroenterologist within a week.</p><p><strong>Results: </strong>The prevalence of EV in the study was 41.5%. Multivariable regression analysis revealed that gender (female, OR = 4.04, <i>p</i> = 0.02), platelet count (<150000 per ml, OR = 3.13, <i>p</i> = 0.09), splenic length (>11 cm, OR = 3.64, <i>p</i> = 0.02), and absent right hepatic vein (RHV) triphasicity (OR = 3.15, <i>p</i> = 0.03) were significant predictors of EV. However, the diagnostic accuracy indices for isolated predictors were not good (AUROC = 0.63-0.66). A combination of these four predictors increases the diagnostic accuracy in predicting the presence of EV (AUROC = 0.80, 95% CI 0.69-0.91). Furthermore, the Doppler assessment of the right hepatic vein waveform showed good reproducibility (<i>κ</i> = 0.76).</p><p><strong>Conclusion: </strong>Combining clinical and Doppler ultrasound features can be used as a screening test for predicting the presence of EV in patients with hepatitis C-related cirrhosis. The practical predictors identified in this study could serve as an alternative to invasive EGD in EV diagnosis. Further studies are needed to explore the diagnostic accuracy of additional noninvasive predictors, such as elastography, to improve EV screening.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10516699/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41147595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Elastography to Evaluate the Early Effects of Bariatric Surgery on Nonalcoholic Fatty Liver Disease.","authors":"Hong Chang Tan,&nbsp;Elizabeth Shumbayawonda,&nbsp;Cayden Beyer,&nbsp;Lionel Tim-Ee Cheng,&nbsp;Albert Low,&nbsp;Chin Hong Lim,&nbsp;Alvin Eng,&nbsp;Weng Hoong Chan,&nbsp;Phong Ching Lee,&nbsp;Mei Fang Tay,&nbsp;Stella Kin,&nbsp;Jason Pik Eu Chang,&nbsp;Yong Mong Bee,&nbsp;George Boon Bee Goh","doi":"10.1155/2023/4228321","DOIUrl":"https://doi.org/10.1155/2023/4228321","url":null,"abstract":"<p><strong>Background: </strong>Bariatric surgery is the most effective treatment for morbid obesity and reduces the severity of nonalcoholic fatty liver disease (NAFLD) in the long term. Less is known about the effects of bariatric surgery on liver fat, inflammation, and fibrosis during the early stages following bariatric surgery.</p><p><strong>Aims: </strong>This exploratory study utilises advanced imaging methods to investigate NAFLD and fibrosis changes during the early metabolic transitional period following bariatric surgery.</p><p><strong>Methods: </strong>Nine participants with morbid obesity underwent sleeve gastrectomy. Multiparametric MRI (mpMRI) and magnetic resonance elastography (MRE) were performed at baseline, during the immediate (1 month), and late (6 months) postsurgery period. Liver fat was measured using proton density fat fraction (PDFF), disease activity using iron-correct T1 (cT1), and liver stiffness using MRE. Repeated measured ANOVA was used to assess longitudinal changes and Dunnett's method for multiple comparisons.</p><p><strong>Results: </strong>All participants (Age 45.1 ± 9.0 years, BMI 39.7 ± 5.3 kg/m²) had elevated hepatic steatosis at baseline (PDFF >5%). In the immediate postsurgery period, PDFF decreased significantly from 14.1 ± 7.4% to 8.9 ± 4.4% (<i>p</i> = 0.016) and cT1 from 826.9 ± 80.6 ms to 768.4 ± 50.9 ms (<i>p</i> = 0.047). These improvements continued to the later postsurgery period. Bariatric surgery did not reduce liver stiffness measurements.</p><p><strong>Conclusion: </strong>Our findings support using MRI as a noninvasive tool to monitor NAFLD in patient with morbid obesity during the early stages following bariatric surgery.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10372298/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9919473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Extraction of Blood and Tissue Time-Activity Curves in Cardiac Mouse FDG PET Imaging by Means of Constrained Nonnegative Matrix Factorization.","authors":"Otman Sarrhini,&nbsp;Pedro D'Orléans-Juste,&nbsp;Jacques A Rousseau,&nbsp;Jean-François Beaudoin,&nbsp;Roger Lecomte","doi":"10.1155/2023/5366733","DOIUrl":"https://doi.org/10.1155/2023/5366733","url":null,"abstract":"<p><p>We propose an enhanced method to accurately retrieve time-activity curves (TACs) of blood and tissue from dynamic 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography (PET) cardiac images of mice. The method is noninvasive and consists of using a constrained nonnegative matrix factorization algorithm (CNMF) applied to the matrix (<i>A</i>) containing the intensity values of the voxels of the left ventricle (LV) PET image. CNMF factorizes <i>A</i> into nonnegative matrices <i>H</i> and <i>W</i>, respectively, representing the physiological factors (blood and tissue) and their associated weights, by minimizing an extended cost function. We verified our method on 32 C57BL/6 mice, 14 of them with acute myocardial infarction (AMI). With CNMF, we could break down the mouse LV into myocardial and blood pool images. Their corresponding TACs were used in kinetic modeling to readily determine the [¹⁸F]FDG influx constant (<i>K</i>_<i>i</i>) required to compute the myocardial metabolic rate of glucose. The calculated <i>K</i>_<i>i</i> values using CNMF for the heart of control mice were in good agreement with those published in the literature. Significant differences in <i>K</i>_<i>i</i> values for the heart of control and AMI mice were found using CNMF. The values of the elements of <i>W</i> agreed well with the LV structural changes induced by ligation of the left coronary artery. CNMF was compared with the recently published method based on robust unmixing of dynamic sequences using regions of interest (RUDUR). A clear improvement of signal separation was observed with CNMF compared to the RUDUR method.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10287520/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9716473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vivo Fluorine Imaging Using 1.5 Tesla MRI for Depiction of Experimental Myocarditis in a Rodent Animal Model.","authors":"Thore Dietrich,&nbsp;Stephan Theodor Bujak,&nbsp;Thorsten Keller,&nbsp;Bernhard Schnackenburg,&nbsp;Riad Bourayou,&nbsp;Rolf Gebker,&nbsp;Kristof Graf,&nbsp;Eckart Fleck","doi":"10.1155/2023/4659041","DOIUrl":"https://doi.org/10.1155/2023/4659041","url":null,"abstract":"<p><p>The usefulness of perfluorocarbon nanoemulsions for the imaging of experimental myocarditis has been demonstrated in a high-field 9.4 Tesla MRI scanner. Our proof-of-concept study investigated the imaging capacity of PFC-based ¹⁹F/¹H MRI in an animal myocarditis model using a clinical field strength of 1.5 Tesla. To induce experimental myocarditis, five male rats (weight ~300 g, age ~50 days) were treated with one application per week of doxorubicin (2 mg/kg BW) over a period of six weeks. Three control animals received the identical volume of sodium chloride 0.9% instead. Following week six, all animals received a single 4 ml injection of an 20% oil-in-water perfluorooctylbromide nanoemulsion 24 hours prior to <i>in vivo</i>¹H/¹⁹F imaging on a 1.5 Tesla MRI. After euthanasia, cardiac histology and immunohistochemistry using CD68/ED1 macrophage antibodies were performed, measuring the inflamed myocardium in <i>μ</i>m² for further statistical analysis to compare the extent of the inflammation with the ¹⁹F-MRI signal intensity. All animals treated with doxorubicin showed a specific signal in the myocardium, while no myocardial signal could be detected in the control group. Additionally, the doxorubicin group showed a significantly higher SNR for ¹⁹F and a stronger CD68/ED1 immunhistoreactivity compared to the control group. This proof-of-concept study demonstrates that perfluorocarbon nanoemulsions could be detected in an <i>in vivo</i> experimental myocarditis model at a currently clinically relevant field strength.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10361831/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9855524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chest X-Ray Images to Differentiate COVID-19 from Pneumonia with Artificial Intelligence Techniques.","authors":"Rumana Islam, Mohammed Tarique","doi":"10.1155/2022/5318447","DOIUrl":"10.1155/2022/5318447","url":null,"abstract":"<p><p>This paper presents an automated and noninvasive technique to discriminate COVID-19 patients from pneumonia patients using chest X-ray images and artificial intelligence. The reverse transcription-polymerase chain reaction (RT-PCR) test is commonly administered to detect COVID-19. However, the RT-PCR test necessitates person-to-person contact to administer, requires variable time to produce results, and is expensive. Moreover, this test is still unreachable to the significant global population. The chest X-ray images can play an important role here as the X-ray machines are commonly available at any healthcare facility. However, the chest X-ray images of COVID-19 and viral pneumonia patients are very similar and often lead to misdiagnosis subjectively. This investigation has employed two algorithms to solve this problem objectively. One algorithm uses lower-dimension encoded features extracted from the X-ray images and applies them to the machine learning algorithms for final classification. The other algorithm relies on the inbuilt feature extractor network to extract features from the X-ray images and classifies them with a pretrained deep neural network VGG16. The simulation results show that the proposed two algorithms can extricate COVID-19 patients from pneumonia with the best accuracy of 100% and 98.1%, employing VGG16 and the machine learning algorithm, respectively. The performances of these two algorithms have also been collated with those of other existing state-of-the-art methods.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9800093/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10464881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Diffusion Tensor Imaging Metrics in Normal-Appearing White Matter to Cerebrovascular Lesions and Correlation with Cerebrovascular Disease Risk Factors and Severity.","authors":"Seyyed M H Haddad,&nbsp;Christopher J M Scott,&nbsp;Miracle Ozzoude,&nbsp;Courtney Berezuk,&nbsp;Melissa Holmes,&nbsp;Sabrina Adamo,&nbsp;Joel Ramirez,&nbsp;Stephen R Arnott,&nbsp;Nuwan D Nanayakkara,&nbsp;Malcolm Binns,&nbsp;Derek Beaton,&nbsp;Wendy Lou,&nbsp;Kelly Sunderland,&nbsp;Sujeevini Sujanthan,&nbsp;Jane Lawrence,&nbsp;Donna Kwan,&nbsp;Brian Tan,&nbsp;Leanne Casaubon,&nbsp;Jennifer Mandzia,&nbsp;Demetrios Sahlas,&nbsp;Gustavo Saposnik,&nbsp;Ayman Hassan,&nbsp;Brian Levine,&nbsp;Paula McLaughlin,&nbsp;J B Orange,&nbsp;Angela Roberts,&nbsp;Angela Troyer,&nbsp;Sandra E Black,&nbsp;Dar Dowlatshahi,&nbsp;Stephen C Strother,&nbsp;Richard H Swartz,&nbsp;Sean Symons,&nbsp;Manuel Montero-Odasso,&nbsp;Ondri Investigators,&nbsp;Robert Bartha","doi":"10.1155/2022/5860364","DOIUrl":"https://doi.org/10.1155/2022/5860364","url":null,"abstract":"<p><p>Alterations in tissue microstructure in normal-appearing white matter (NAWM), specifically measured by diffusion tensor imaging (DTI) fractional anisotropy (FA), have been associated with cognitive outcomes following stroke. The purpose of this study was to comprehensively compare conventional DTI measures of tissue microstructure in NAWM to diverse vascular brain lesions in people with cerebrovascular disease (CVD) and to examine associations between FA in NAWM and cerebrovascular risk factors. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured in cerebral tissues and cerebrovascular anomalies from 152 people with CVD participating in the Ontario Neurodegenerative Disease Research Initiative (ONDRI). Ten cerebral tissue types were segmented including NAWM, and vascular lesions including stroke, periventricular and deep white matter hyperintensities, periventricular and deep lacunar infarcts, and perivascular spaces (PVS) using T₁-weighted, proton density-weighted, T₂-weighted, and fluid attenuated inversion recovery MRI scans. Mean DTI metrics were measured in each tissue region using a previously developed DTI processing pipeline and compared between tissues using multivariate analysis of covariance. Associations between FA in NAWM and several CVD risk factors were also examined. DTI metrics in vascular lesions differed significantly from healthy tissue. Specifically, all tissue types had significantly different MD values, while FA was also found to be different in most tissue types. FA in NAWM was inversely related to hypertension and modified Rankin scale (mRS). This study demonstrated the differences between conventional DTI metrics, FA, MD, AD, and RD, in cerebral vascular lesions and healthy tissue types. Therefore, incorporating DTI to characterize the integrity of the tissue microstructure could help to define the extent and severity of various brain vascular anomalies. The association between FA within NAWM and clinical evaluation of hypertension and disability provides further evidence that white matter microstructural integrity is impacted by cerebrovascular function.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2022-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9616672/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40445853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards an Accurate MRI Acute Ischemic Stroke Lesion Segmentation Based on Bioheat Equation and U-Net Model.","authors":"Abdelmajid Bousselham,&nbsp;Omar Bouattane,&nbsp;Mohamed Youssfi,&nbsp;Abdelhadi Raihani","doi":"10.1155/2022/5529726","DOIUrl":"https://doi.org/10.1155/2022/5529726","url":null,"abstract":"<p><p>Acute ischemic stroke represents a cerebrovascular disease, for which it is practical, albeit challenging to segment and differentiate infarct core from salvageable penumbra brain tissue. Ischemic stroke causes the variation of cerebral blood flow and heat generation due to metabolism. Therefore, the temperature is modified in the ischemic stroke region. In this paper, we incorporate acute ischemic stroke temperature profile to reinforce segmentation accuracy in MRI. Pennes bioheat equation was used to generate brain thermal images that may provide rich information regarding the temperature change in acute ischemic stroke lesions. The thermal images were generated by calculating the temperature of the brain with acute ischemic stroke. Then, U-Net was used in this paper for the segmentation of acute ischemic stroke. A dataset of 3192 images was created to train U-Net using <i>k</i>-fold crossvalidation. The training time was about 10 hours and 35 minutes in NVIDIA GPU. Next, the obtained trained model was compared with recent methods to analyze the effect of the ischemic stroke temperature profile in segmentation. The obtained results show that significant parts of acute ischemic stroke and background areas are segmented only in thermal images, which proves the importance of using thermal information to improve the segmentation outcomes in MRI diagnosis.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2022-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9308529/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40648868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Left Ventricle Segmentation in Cardiac MR Images via an Improved ResUnet.","authors":"Shengzhou Xu, Haoran Lu, Shiyu Cheng, Chengdan Pei","doi":"10.1155/2022/8669305","DOIUrl":"10.1155/2022/8669305","url":null,"abstract":"<p><p>Cardiovascular diseases are reported as the leading cause of death around the world. Automatic segmentation of the left ventricle (LV) from magnetic resonance (MR) images is essential for an early diagnosis. An enhanced ResUnet is proposed in this paper to improve the performance of extracting LV endocardium and epicardium from MR images, improving the accuracy of the model by introducing a medium skip connection for the contracting path and a short skip connection for the residual unit. Also, a depth-wise separable convolution replaces the typical convolution operation to improve training efficiency. In the MICCAI 2009 LV segmentation challenge test dataset, the percentages of \"good\" contours, dice metric, and average perpendicular distance of endocardium (epicardium) are 99.12% ± 2.29%(100% ± 0%), 0.93 ± 0.02 (0.96 ± 0.01), and 1.60 ± 0.42 mm (1.37 ± 0.23 mm), respectively. Experimental results demonstrate that the proposed model obtains promising performance and outperforms state-of-the-art methods. By incorporating these various skip connections, the segmentation accuracy of the model is significantly improved, while the depth-wise separable convolution also improves the model efficiency.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9286995/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40531409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myocardium Assessment by Relaxation along Fictitious Field, Extracellular Volume, Feature Tracking, and Myocardial Strain in Hypertensive Patients with Left Ventricular Hypertrophy.","authors":"Seyed Amir Mirmojarabian, Eveliina Lammentausta, Esa Liukkonen, Lauri Ahvenjärvi, Juhani Junttila, Miika T Nieminen, Timo Liimatainen","doi":"10.1155/2022/9198691","DOIUrl":"10.1155/2022/9198691","url":null,"abstract":"<p><strong>Background: </strong>Previous research has shown impaired global longitudinal strain (GLS) and slightly elevated extracellular volume fraction (ECV) in hypertensive patients with left ventricular hypertrophy (HTN LVH). Up to now, only little attention has been paid to interactions between macromolecules and free water in hypertrophied myocardium.</p><p><strong>Purpose: </strong>To evaluate the feasibility of relaxation along a fictitious field with rank 2 (RAFF2) in HTN LVH patients. <i>Study Type.</i> Single institutional case control.</p><p><strong>Subjects: </strong>9 HTN LVH (age, 69 ± 10 years) and 11 control subjects (age, 54 ± 12 years). <i>Field Strength/Sequence.</i> Relaxation time mapping (<i>T</i> ₁, <i>T</i> _1<i>ρ</i> , and <i>T</i> _RAFF2 with 11.8 <i>μ</i>T maximum radio frequency field amplitude) was performed at 1.5 T using a Siemens Aera (Erlangen, Germany) scanner equipped with an 18-channel body array coil. <i>Assessment.</i> ECV was calculated using pre- and postcontrast <i>T</i> ₁, and global strains parameters were assessed by Segment CMR (Medviso AB Co, Sweden). The parametric maps of <i>T</i> _1<i>ρ</i> and <i>T</i> _RAFF2 were computed using a monoexponential model, while the Bloch-McConnell equations were solved numerically to model effect of the chemical exchange during radio frequency pulses. <i>Statistical Tests.</i> Parametric maps were averaged over myocardium for each subject to be used in statistical analysis. Kolmogorov-Smirnov was used as the normality test followed by Student's t-test and Pearson's correlation to determine the difference between the HTN LVH patients and controls along with Hedges' <i>g</i> effect size and the association between variables, respectively.</p><p><strong>Results: </strong><i>T</i> _RAFF2 decreased statistically (83 ± 2 ms vs 88 ± 6 ms, <i>P</i> < 0.031), and global longitudinal strain was impaired (GLS, -14 ± 3 vs - 18 ± 2, <i>P</i> < 0.002) in HTN LVH patients compared to the controls, respectively. Also, significant negative correlation was found between <i>T</i> _RAFF2 and GLS (<i>r</i> = -0.53, <i>P</i> < 0.05). <i>Data Conclusion.</i> Our results suggest that <i>T</i> _RAFF2 decrease in HTN LVH patients may be explained by gradual collagen accumulation which can be reflected in GLS changes. Most likely, it increases the water proton interactions and consequently decreases <i>T</i> _RAFF2 before myocardial scarring.</p>","PeriodicalId":47063,"journal":{"name":"International Journal of Biomedical Imaging","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9246602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40466387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}