Perfusion Abnormalities Research Articles

Intravoxel incoherent motion imaging in stroke infarct core and penumbra is related to long-term clinical outcome

Intravoxel incoherent motion (IVIM) imaging, a contrast agent-free magnetic resonance imaging technique, enables the evaluation of microvascular perfusion abnormalities in acute stroke. Prior research reported reduced IVIM values within the infarct core in acute stroke. However, findings concerning IVIM characteristics in the penumbra have been mixed and the relationship between IVIM and clinical outcomes remains unknown. We employed a longitudinal multimodal imaging approach for ischemic stroke patients (n analyzed=24; pre-/post-treatment and 90-day post-stroke assessments) including IVIM, diffusion-weighted, and contrast-enhanced perfusion-weighted imaging. We evaluated IVIM in relevant stroke areas after endovascular treatment. Reduced post-treatment IVIM perfusion fraction in infarct core and recanalized penumbra was associated with poorer functional recovery at 90-days post-stroke (NIH Stroke Scale [NIHSS]; r=-0.64 and r=-0.69). Including IVIM perfusion fraction increased the explained variance of NIHSS from 42% up to 83% compared to well-known prognostic factors core volume and patient age. Additionally, IVIM perfusion fraction was reduced in the core and recanalized penumbra compared to contralateral healthy tissue, suggesting impaired microvascular reperfusion after endovascular treatment. In conclusion, IVIM characteristics of the infarct core and recanalized penumbra are strong prognostic factors for long-term outcome in stroke patients and IVIM shows promise for characterizing microvascular perfusion in relevant stroke areas.

Clinical and imaging characteristics associated with foveal neovascularization in proliferative diabetic retinopathy.

To assess the prevalence of foveal neovascularization (FNV) and its associated clinical features in proliferative diabetic retinopathy (PDR) eyes. Cross-sectional observational study. Participants underwent ultra-widefield photography, optical coherence tomography (OCT), and swept-source OCT angiography (SS-OCTA). FNV was defined as a hyperreflective lesion breaching the internal limiting membrane and displaying flow signal on OCTA, within 1-mm of foveal avascular zone. Vascular metrics were obtained from the ARI Network portal. Ischemic index (ISI) and inner choroid flow deficit percentage were calculated using FIJI from 12 × 12 and 6 × 6-mm scans, respectively. Logistic regression models were used to compare eyes with and without FNV. We included 249 eyes of 164 patients (age: 58 [50-65] years). FNV was identified in 20 eyes (8%). Univariate logistic regression revealed significant associations between FNV and younger age (p = 0.03), higher maximal HbA1c (p = 0.04), worse visual acuity (VA) (p = 0.01), presence of disorganization of retinal inner layers (DRIL) (p = 0.01), no macular posterior vitreous detachment (PVD) (p = 0.03), neovascularization elsewhere (NVE) and at the disc (NVD) (p = 0.01 and p = 0.001), and greater ISI (p = 0.04). In multivariable analysis, a significant association remained between FNV and worse VA (p = 0.04), NVD (p < 0.001), DRIL (p < 0.001), and absence of macular PVD (p = 0.01). No associations were found with SS-OCTA vascular metrics. This study provides a comprehensive characterization of FNV in PDR. FNV was identified in 8% of our cohort, being more prevalent in younger patients with severe PDR, as evidenced by NVD and DRIL presence. The absence of macular PVD may explain its association with younger age. What is known • Neovascularization at the fovea occurs rarely in proliferative diabetic retinopathy. • OCT and OCT-angiography can be used to evaluate foveal neovascularization, which may be associated with choroidal vascular abnormalities. What is new • Foveal neovascularization was seen in 8% of eyes with proliferative diabetic retinopathy in this cohort. • Risk factors for foveal neovascularization included younger age, absence of macular posterior vitreous detachment, presence of neovascularization of the disc, and presence of disorganization of retinal inner layers. • We did not identify an association between foveal neovascularization and choroidal perfusion abnormalities in this study.

Prognostic value of Transient Ischemic Dilation on Rubidium-82 Positron Emission Tomography Myocardial Perfusion Imaging

RationaleTransient ischemic dilation (TID) of the left ventricular (LV) cavity is considered a high-risk marker in patients with abnormal single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Stress image acquisition in Rubidium-82 (82Rb) PET occurs at peak stress compared to 30-60 minutes post stress with SPECT. We aimed to evaluate the prognostic value of TID among patients undergoing 82Rb PET MPI. MethodsA total of 9878 consecutive patients with LVEF ≥40% undergoing rest/pharmacologic stress 82Rb PET MPI from 2010-2016 were followed for a median of 3.2 years. The primary clinical outcome of cardiac death was assessed after adjusting for pre-test risk, known coronary artery disease (CAD), rest left ventricular ejection fraction (LVEF), summed stress score (SSS), LVEF reserve (LVEF-R), myocardial blood flow reserve (MBFR) and early (90-day) revascularization. Pre-specified interactions between TID ratio and SSSwere included to assess potential differences in the prognostic value of TID in patients based on perfusion. ResultsMean age of the cohort was 69.0 (11.7) years, 56.1% female, 49.8% with known CAD, 27.9% with abnormal perfusion (SSS>0).There were 451 cardiac deaths. Higher TID ratio was associated with a significantly higher risk of cardiac death, even after accounting for LVEF-R and MBFR (HR per 0.1 unit increase =1.25 (1.11, 1.41), p<0.001). This was seen both among patients with normal (HR for TID per 0.1 unit increase= 1.24 (95% CI: 1.01, 1.52), p=0.04) and abnormal (HR for TID per 0.1 unit increase= 1.14 (95% CI: 1.02, 1.28), p=0.03) perfusion. ConclusionTID on rest/stress 82RbPET MPI offers independent prognostic value in patients with both normal and abnormal perfusion beyond other risk markers, among patients with LVEF >40%.

Que peut nous apprendre l’étude du métabolisme cérébral en TEP au 18F-FDG du syndrome de Lance-Adams ?

Lance-Adams syndrome, also known as “chronic post-anoxic myoclonus”, is a rare syndrome characterised by intention and action myoclonus following cerebral anoxia, leading to major disability. The cortical or subcortical origin of the myoclonus is still debated. Answering this question would open up new avenues of translational research to gain a better understanding of the pathophysiology of this syndrome and better guide the therapeutic management of patients. In addition to a neurological examination, the initial diagnostic work-up includes a biological work-up, electrophysiological investigations and brain imaging to rule out diGerential diagnoses. Cerebral MRI is the reference imaging technique. In the literature, more than a third of patients have a normal MRI. MRI is used to rule out a vascular cause and to look for atrophy or neuronal damage. Few data are available in the literature on the role of nuclear medicine. To date, 13 cases have been published using 18F-FDG PET and 4 using cerebral perfusion scintigraphy. Abnormalities of cortical and/or subcortical perfusion or metabolism are reported in 65% of cases; they are limited to the neocortex in 23% and aGect the cerebellum in 12% of cases. In this article, we present three patients who underwent cerebral 18F-FDG PET scans for Lance-Adams syndrome with normal MRI. The results of these examinations are discussed and compared with the data found in the literature.

Pseudo hepatic vein thrombosis in a newborn with infracardiac total anomalous pulmonary venous connection.

We report an interesting incidental liver finding during ECG-gated cardiac computed tomography (CT) in a newborn with infracardiac total anomalous pulmonary venous connection to the portal vein. This case shows a unique abnormality in hepatic perfusion that was initially mistaken for hepatic vein thrombosis. We review the altered hepatic blood flow distribution in this pathologic anatomy to help explain the observed hepatic perfusion abnormality on CT. This understanding will enable an imager to anticipate hepatic perfusion patterns in similar patients, potentially avoiding misdiagnosis and unnecessary further testing.

Perfusion metabolism mismatch predicts short-term complications in Takotsubo syndrome

Abstract Background Takotsubo syndrome (TTS) is a transient cardiac condition triggered by sudden emotional or physical stress characterized by LV dysfunction in the absence of obstructive epicardial coronary artery disease. 123I-BMIPP, an iodinated fatty acid analogue, can identify impaired myocardial metabolic activity. With the use of dual SPECT protocol, reduced uptake of 123I-BMIPP compared to perfusion which is called perfusion-metabolic mismatch is observed in apical regions in TTS. The mismatch may indicate jeopardized but viable myocardium, reflecting transient ischemic damage or metabolically stunned myocardium. However, the association between the perfusion metabolism mismatch in TTS and its complications remains underexplored. Purpose Our study aimed to analyze the degree of perfusion metabolism mismatch at the acute phase in TTS and investigate its association with short-term complications. Methods This retrospective study conducted between 2012 and 2024 at a single center included 82 patients diagnosed with TTS. Patients underwent dual SPECT imaging using 99mTc or 201 Tl and 123I-BMIPP within two weeks of admission. We applied quantitative analysis using QGS/QPS software from Cedars-Sinai. Total perfusion deficit ("TPD") was calculated based on sex-matched normal limits providing the extent of perfusion abnormality. Meanwhile, perfusion-metabolism mismatch scores ("worsen") were determined by comparing the total BMIPP counts to the total counts of perfusion. We then assessed the correlation of these imaging findings with biomarkers, regional wall motion abnormalities, and the occurrence of short-term complications. Short-term complications included heart failure, left ventricular outflow (LVOT) obstruction, mitral regurgitation, cardiac arrhythmia, cardiogenic shock, left ventricle (LV) rupture, and cardiac death during the hospitalization period. Results All study patients exhibited wall motion abnormalities seen in apical segments. The count of myocardial segments with regional wall motion abnormality was correlated with both TPD (r=0.34, p=0.002) and perfusion metabolic mismatch score (r=0.40, p&amp;lt;0.001). TPD had a moderate correlation coefficient with max CK-MB (r=0.44, p&amp;lt;0.001) and troponin T (r=0.40, p&amp;lt;0.001) levels. However, perfusion metabolic mismatch did not display correlations with max CK-MB (r=0.05, p=0.65), and Troponin T (r=0.12, p=0.28) levels. Among 82 patients, 37 patients experienced any short-term complications. Importantly, patients with short-term complications had elevated perfusion mismatch scores compared to those without short-term complications (14.0 [6.0-22.5] vs. 5.0 [3.0-10.0], p&amp;lt;0.001). However, no significant difference was observed in TPD between the two groups (9.0 [4.5-20.0] vs. 7.0 [3.0-12.0], p=0.130). Conclusions Our research highlights a significant association between perfusion-metabolism mismatch and an increased risk for short-term complications in patients with Takotsubo syndrome.

Predictive value of myocardial contrast echocardiography in evaluating myocardial perfusion and prognosis after percutaneous coronary intervention in patients with acute myocardial infarction

Objective: To evaluate myocardial microcirculation perfusion with myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction after percutaneous coronary intervention (PCI), and to explore the prognostic value of different types of myocardial microcirculation perfusion. Methods: This is a prospective cohort study. Patients with acute myocardial infarction who underwent successful PCI in Nanfang Hospital of Southern Medical University and Kanghua Hospital of Dongguan City from October 2019 to June 2021 were selected. All the enrolled patients completed MCE examination within 72 hours after PCI. According to the examination results, the patients were divided into normal microcirculation perfusion group, delayed microcirculation perfusion group, and blocked microcirculation perfusion group. Adverse cardiovascular events including all-cause death, cardiovascular death, and angina re-hospitalization were followed up, and left ventricular ejection fraction (LVEF) review results were collected at six months to one year after surgery. Kaplan-Meier survival curve was used to investigate the difference in the incidence of adverse cardiovascular events in different myocardial perfusion groups, and Cox regression analysis was used to evaluate the effect of myocardial perfusion on adverse cardiovascular events. Results: A total of 113 patients with acute myocardial infarction were included, aged (56.3±11.5) years, with 88(78%) males. There were 31 cases in the normal microcirculation perfusion group, 43 cases in the delayed microcirculation perfusion group and 39 cases in the blocked microcirculation perfusion group. LVEF was reviewed in 49 patients, and LVEF in the delayed microcirculation perfusion group was significantly improved compared with baseline at follow-up ((63.3±1.2) % vs. (58.6±1.8) %, P=0.043), and there was no statistically significant difference between the other two groups (all P>0.05). The median follow-up time was 473 days, during follow-up period 30 adverse cardiovascular events occurred. Kaplan-Meier survival curve analysis showed that there was a statistically significant difference in the incidence of adverse cardiovascular events among the three groups (Plog-rank=0.029). Cox regression analysis showed that abnormal microcirculation perfusion (defined as delayed and blocked microcirculation perfusion) was an independent predictor of adverse cardiovascular events in patients with acute myocardial infarction after PCI (HR=1.90, 95%CI1.16-3.12, P=0.011). Conclusions: Microcirculatory perfusion decrease or lost is common in patients with acute myocardial infarction after PCI. Timely restoration of blood flow reconstruction can save heart function when microcirculatory perfusion decreases. Microcirculatory perfusion is a predictor of adverse cardiovascular events in patients with acute myocardial infarction, and patients with poor myocardial perfusion are more likely to experience adverse cardiovascular events.

Diagnostic Value of Magnetocardiography to Detect Abnormal Myocardial Perfusion: A Pilot Study.

Magnetocardiography (MCG) is a novel non-invasive technique that detects subtle magnetic fields generated by cardiomyocyte electrical activity, offering sensitive detection of myocardial ischemia. This study aimed to assess the ability of MCG to predict impaired myocardial perfusion using single-photon emission computed tomography (SPECT). A total of 112 patients with chest pain underwent SPECT and MCG scans, from which 65 MCG output parameters were analyzed. Using least absolute shrinkage and selection operator (LASSO) regression to screen for significant MCG variables, three machine learning models were established to detect impaired myocardial perfusion: random forest (RF), decision tree (DT), and support vector machine (SVM). The diagnostic performance was evaluated based on the sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). Five variables, the ratio of magnetic field amplitude at R-peak and positive T-peak (RoART+), R and T-peak magnetic field angle (RTA), maximum magnetic field angle (MAmax), maximum change in current angle (CCAmax), and change positive pole point area between the T-wave beginning and peak (CPPPATbp), were selected from 65 automatic output parameters. RTA emerged as the most critical variable in the RF, DT, and SVM models. All three models exhibited excellent diagnostic performance, with AUCs of 0.796, 0.780, and 0.804, respectively. While all models showed high sensitivity (RF = 0.870, DT = 0.826, SVM = 0.913), their specificity was comparatively lower (RF = 0.500, DT = 0.300, SVM = 0.100). Machine learning models utilizing five key MCG variables successfully predicted impaired myocardial perfusion, as confirmed by SPECT. These findings underscore the potential of MCG as a promising future screening tool for detecting impaired myocardial perfusion. ChiCTR2200066942, https://www.chictr.org.cn/showproj.html?proj=187904.

Utility of automated CT perfusion software in acute ischemic stroke with large and medium vessel occlusion.

Early diagnosis of large vessel occlusion (LVO) in acute stroke often requires CT angiography (CTA). Automated CT perfusion (CTP) software, which identifies blood flow abnormalities, enhances LVO diagnosis and patient selection for endovascular thrombectomy (EVT). This study evaluates the sensitivity of automated CTP images in detecting perfusion abnormalities in patients with acute ischemic stroke (AIS) and LVO or medium vessel occlusion (MeVO), compared to CTA. We screened acute ischemic stroke patients presenting within 24 h who underwent CT, CTA, and CTP as per institutional protocol. RAPID AI software processed CTP images, while neuroradiologists reviewed CTA for intracranial arterial occlusions. Sensitivity, specificity, and accuracy of automated CTP maps in detecting occlusions were assessed. Of 790 screened patients, 31 were excluded due to lack of RAPID CTP data or poor-quality scans, leaving 759 for analysis. The median age was 71 years (IQR: 61-81), with 47% female. Among them, 678 had AIS, and 81 had AIS ruled out. CTA identified arterial occlusion in 562 patients (74%), with corresponding CTP abnormalities in 537 patients (Tmax > 6 sec). In the 197 without occlusion, CTP was negative in 161. Automated CTP maps had a sensitivity of 95.55% (CI 95: 93.50-97.10%), specificity of 81.73% (CI 95: 75.61-86.86%), negative predictive value of 98.22% (CI 95: 97.39-98.79%), positive predictive value of 63.54% (CI 95: 56.46-70.09%), and overall accuracy of 85.18% (CI 95: 82.45-87.64%). Automated CTP maps demonstrated high sensitivity and negative predictive value for LVOs and MeVOs, suggesting their usefulness as a rapid diagnostic tool, especially in settings without expert neuroradiologists.

The application of mass defect percentage in the evaluation of acute coronary syndrome.

White blood cells, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) distribution patterns in patients with anatomic coronary disease have previously been associated with cardiac events such as myocardial infarct size, complications, and prognosis. However, it remains unknown whether myocardial perfusion mass defect percentage (MDP) obtained from gated myocardial perfusion imaging (G-MPI) correlates with these hematological parameters. Therefore, our research aimed to investigate the application of MDP in the evaluation of acute coronary syndrome (ACS). Thirty-six patients with ACS underwent single-photon emission computed tomography/computed tomography using retrospective electrocardiography gating during the resting state. The primary outcome was the percentage of left ventricular mass with abnormal myocardial perfusion (i.e. MDP) in G-MPI. Furthermore, the correlation between myocardial perfusion MDP and lymphocyte count, neutrophil count, white blood cell count, and NLR was calculated. In addition, we explored the relationship of myocardial perfusion MDP with other cardiac function parameters obtained from G-MPI, such as summed rest score, left ventricular ejection fraction, end-systolic volume, and end-diastolic volume. Myocardial perfusion MDP significantly correlated with white blood cell count, neutrophil count, and NLR (P < 0.01). Furthermore, these hematological parameters were significantly different between low and high MDP groups. Additionally, myocardial perfusion MDP negatively correlated with end-systolic volume (r = -0.615) and left ventricular ejection fraction (r = -0.657). Myocardial perfusion MDP has a high correlation with inflammatory cell counts and cardiac function parameters obtained from G-MPI in ACS; this may be of help in the evaluation and treatment of these patients.

Myocardial Perfusion Scintigraphy in Diagnosic of Coronary Heart Disease

&amp;lt;i&amp;gt;Introduction: &amp;lt;/i&amp;gt;Atherosclerosis plays a key role in the etiopathogenesis of cardiovascular diseases. Atherosclerosis is a generalized chronic inflammatory disease of the vascular wall, which results in anatomical and histological changes that, together with functional changes, lead to endothelial dysfunction, narrowing of the arterial lumen, and insufficient blood supply to the tissues. The shift in the incidence of cardiovascular diseases to younger age groups is alarming. The presence of microvascular changes in the myocardium is significant. The high incidence of cardiovascular diseases, especially ischemic heart disease, requires early diagnosis and modern treatment. &amp;lt;i&amp;gt;Aim: &amp;lt;/i&amp;gt;The aim of the paper is to analyse and point out early diagnosis of coronary heart disease using nuclear medicine methods. &amp;lt;i&amp;gt;Set of examined patients and methodology: &amp;lt;/i&amp;gt;Using nuclear medicine methods, we try to detect these changes in time and thus prevent the occurrence of acute coronary events. In nuclear cardiology, instead of a large-area scintillation detector, a new type of cardio-gamma camera &amp;quot;Discovery CZT 530c&amp;quot; based on the principle of semiconductor detectors began to be used. The abbreviation CZT stands for semiconductor composition (Cadmium-Zinc-Tellur). The set of respondents consisted of 4270 people examined in the years 2014-2016 by myocardial perfusion scintigraphy. There were 950 diabetic patients in the analysed group of the 4270 examined. &amp;lt;i&amp;gt;Results:&amp;lt;/i&amp;gt; In the analysed group of 4270 respondents, 61% had negative findings and 39% had positive findings in terms of the presence of ischemic heart disease. In the group of diabetic patients, there was a negative finding in 28% of respondents and a positive finding in 72% of the respondents in the sense of positive ischemic heart disease. Using myocardial perfusion scintigraphy in the diagnosis of functional changes, we confirmed a great benefit in detecting early changes in coronary heart disease, including in the diagnosis of microvascular angina. &amp;lt;i&amp;gt;Conclusion:&amp;lt;/i&amp;gt; Nuclear medicine methods are of great benefit for the diagnosis of small vessel disease, diabetic cardiomyopathy and cardiac autonomic neuropathy in patients with diabetes mellitus. The new type of cardio gamma camera &amp;quot;Discovery CZT 530c&amp;quot; allows more accurate assessment of myocardial perfusion abnormalities and at the same time the reduction of the radiopharmaceutical dose reduces the patient&amp;apos;s radiation load by 50%.

Comparative study of myocardial perfusion and coronary flow velocity reserve derived from adenosine triphosphate stress myocardial contrast echocardiography in coronary lesions with no/mild stenosis.

Qualitative myocardial perfusion (QMP) derived from myocardial contrast echocardiography reflects the capillary flow, while coronary flow velocity reserve from Doppler spectrum (D-CFVR) of the left anterior descending coronary artery (LAD) is used to assess coronary microvascular function, particularly after excluding severe epicardial coronary stenosis. The present study aimed to assess the relationship of QMP and D-CFVR in detecting coronary microvascular disease (CMVD) by using adenosine triphosphate stress myocardial contrast echocardiography (ATP stress MCE). Seventy-two patients (mean age: 54.22 ± 12.78 years) with chest pain and <50% coronary stenosis diagnosed by quantitative coronary angiography or dual-source CT underwent ATP stress MCE. The distribution of myocardial perfusion and CFVR value was estimated by experienced physicians. Of the 72 LAD with 0%-50% diameter stenosis, 15 (21%) exhibited abnormal CFVR and 31 (43%) displayed abnormal perfusion with ATP stress MCE. Eleven of the 15 LAD territories (73%) with abnormal CFVR values showed abnormal perfusion. However, CFVR was considered normal in 20 LAD territories (35%), despite the presence of perfusion defect in the territory. Abnormal myocardial perfusion during ATP stress MCE was found in a sizable percentage of patients in whom CFVR of the supplying vessel was considered normal.

Diagnostic utility of coronary artery calcium score percentiles and categories to exclude abnormal scans and relevant ischemia in rubidium positron emission tomography.

Despite clinical suspicion, most non-invasive ischemia tests for coronary artery disease (CAD) reveal unremarkable results. Patients with a coronary artery calcium score (CACS) of zero rarely have an abnormal positron emission tomography (PET) and could be deferred from further testing. However, most patients have some extent of coronary calcification. CACS percentiles could be useful to exclude abnormal perfusion in patients with CACS >0, but data from patients with 82Rb PET are lacking. The aim of this study was to assess the diagnostic utility of CACS percentiles in comparison to zero calcium and absolute CACS classes. Consecutive patients with suspected CAD (n = 1,792) referred for 82Rb PET were included and analyzed for abnormal PET (SSS ≥4) and relevant ischemia (>10% myocardium). Test characteristics were calculated. The mean age was 65 ± 11 years, 43% were female, and typical angina was reported in 21%. Abnormal PET/relevant ischemia (>10%) were observed in 19.8%/9.3%. Overall, the sensitivity/negative predictive value (NPV) of a <25th percentile CACS to rule out abnormal PET and relevant ischemia were 93.0%/95.7% and 98.2%/99.5%, respectively. The sensitivity/NPV of CACS 1-9 to rule out abnormal PET and relevant ischemia were 96.0%/91.8% and 97.6%/97.6%, respectively. Except for patients <50 years old, sensitivity for abnormal PET was >90.9% in all age groups. In patients >50 years, the <25th percentile and CACS 1-9 had good test characteristics to rule out abnormal PET and relevant ischemia (>10%). They could be used to extend the scope of application of CACS 0 by 8%-10% to 32%-34% overall of patients who could be deferred from further testing.

The Current and Novel Imaging Modalities for Ocular Vasculitis in Behcet's Disease: A Review.

Behcet's syndrome is a multisystem inflammatory disorder characterized by a chronic relapsing course and diverse clinical manifestations, prominently affecting young adults along the ancient Silk Road and beyond. The disease pathogenesis involves complex interactions between genetic predisposition, environmental triggers, and dysregulated immune responses, leading to systemic vasculitis and tissue damage. Ocular involvement, a hallmark of Behcet's Disease (BD), significantly impacts morbidity, with uveitis as a common initial presentation that can progress to severe vision-threatening complications like retinal vasculitis and occlusive disease. This review consolidates current knowledge on ocular manifestations in BD, emphasizing the pivotal role of multimodal imaging in diagnostic evaluation and management. Fundus photography serves as a baseline tool for documenting intraocular lesions and monitoring treatment responses. Fluorescein angiography remains the gold standard for detecting acute inflammatory changes and vascular leakage patterns essential for disease staging and prognostication. Recent advancements in imaging, such as ultra-wide field imaging (UWF), indocyanine green angiography (ICGA), Doppler ultrasonography, Optical Coherence Tomography (OCT), OCT angiography (OCTA), adaptive optics (AO), and retinal function imaging (RFI), provide unprecedented insights into microvascular dynamics, structural changes, and functional impairments associated with ocular BD. Integration of these advanced imaging modalities enhances early detection of subclinical disease, facilitates precise localization of inflammatory lesions, guides therapeutic interventions, and monitors treatment efficacy. OCT and OCTA, in particular, offer non-invasive, high-resolution assessments of macular edema, vascular perfusion abnormalities, and choroidal thickness alterations critical for optimizing patient care. In conclusion, multimodal imaging represents the cornerstone in the comprehensive management of ocular manifestations in Behcet's Disease, offering clinicians invaluable tools for accurate diagnosis, treatment planning, and long-term monitoring of disease progression and treatment outcomes.

Dual hyperpolarized [1-13C]pyruvate and [13C]urea magnetic resonance imaging of prostate cancer

BackgroundAlthough multiparametric (mp) 1H magnetic resonance imaging (MRI) is increasingly used to detect and localize prostate cancer (PC), its correlation with tumor grade is limited. Hyperpolarized (HP) carbon-13 (13C) MR is an emerging imaging technique, which can be used to interrogate key biologic processes through in vivo detection of various HP probes. A distinct attribute of HP 13C MRI is the ability to detect multiple HP probes within a single acquisition. Here we report on the first simultaneous dual HP [1-13C]pyruvate and [13C]urea MRI with correlations to histopathologic findings in a patient with localized PC scheduled for radical prostatectomy. Material and methodsPaired HP 13C and standard mp 1H MRI were performed in a patient with biopsy-proven Gleason score 4 + 3 = 7 adenocarcinoma of the prostate scheduled for radical prostatectomy through a first-in-human pilot study of dual-agent HP MRI (NCT02526368). HP 13C MRI was performed using a clinical 3T scanner with 13C transmit-and-receive capabilities. Dynamic series of HP 13C pyruvate, lactate and urea imaging were acquired following intravenous (IV) injection of co-hyperpolarized [13C]urea (25 mM) and [1–13C]pyruvate (125 mM). The [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) was calculated using an inputless two-site exchange model; AUCurea was the [13C]urea signal summed over time. Following radical prostatectomy, whole-mount prostate histopathological slides were prepared and reviewed by an experienced genitourinary pathologist. ResultsFollowing informed consent, the patient underwent paired mp 1H MRI and dual-agent HP MRI. mp 1H MRI revealed a 1.2 cm lesion in the left apical posterior zone. Dual-agent HP MRI identified a focus of increased [1-13C]pyruvate-to-[1-13C]lactate conversion rate (kPL) extending from the left apical posterior peripheral zone to the right gland. A corresponding area of abnormal tissue perfusion (AUCurea) was seen in the left gland. Metabolism-perfusion mismatch (with several foci of increased kPL/AUCurea) was observed throughout the tumor. Tumor extension to the right midgland was confirmed at the time of radical prostatectomy and staining for lactate dehydrogenase-A was increased throughout the tumor relative to surrounding benign prostatic tissue. ConclusionThis first-in-human radiopathologic study demonstrates the feasibility of dual-agent HP MRI in PC patients. Simultaneous assessment of tumor metabolism and perfusion was able to detect occult disease as well as to show a significant mismatch between intra-tumoral metabolism and tissue perfusion in high-grade PC. Prospective validation of these findings is warranted.

Longitudinal Magnetic Resonance Imaging of Changes in Lung Morphology and Perfusion in Children with Cystic Fibrosis From Infancy through Adolescence.

The progression of lung changes in cystic fibrosis (CF) from infancy through adolescence remains poorly understood due to limited longitudinal imaging data. To assess changes in lung morphology and perfusion in children with CF through the pediatric age range by longitudinal chest magnetic resonance imaging (MRI). 1112 annual chest MRI were performed in 226 patients with CF aged 0-18yr. MRI was assessed using a validated MRI scoring system. The MRI global score continuously increased from 5.5±4.6 at infancy (0yr) to 17.9±8.4 at adolescence (range 12-18yr), and the MRI morphology score from 5.0±3.9 to 12.4±6.0 (P<0.001). Bronchiectasis/wall thickening prevalence increased from 89.1% at infancy to approx. 100% from preschool age (1-5yr), and the subscore increased from 3.1±1.9 at infancy to 6.6±2.1 at adolescence (P<0.001). Mucus plugging prevalence increased from 55.4% at infancy to 83.5% at adolescence, and the subscore increased from 1.2±1.6 to 3.7±2.5 in the same period (P<0.001). Perfusion abnormalities were found in 44.4% at infancy, and increased to approx. 90% from preschool age (P<0.001). The MRI perfusion score increased from 1.1±1.6 at infancy to 5.6±3.0 at adolescence (P<0.001). Chronic Pseudomonas aeruginosa infection was associated with higher MRI scores from school age (6-11yr, P<0.05-0.001). This is the first study assessing longitudinal changes in lung morphology and perfusion in CF throughout the pediatric age range, providing percentiles as age-specific reference for lung disease severity. Our data may facilitate the use of MRI as an endpoint in clinical trials in children with CF.

Prognostic value of transient ischemic dilatation by 13N-ammonia PET MPI for short-term outcomes in patients with non-obstructive CAD

Abstract Objective Transient ischaemic dilatation (TID) had incremental diagnostic and prognostic value in obstructive coronary artery disease (CAD), but its clinical significance in patients with non-obstructive CAD remains unknown. We aimed to explore the prognostic value of TID in patients with non-obstructive CAD by 13N-ammonia PET imaging. Methods We retrospectively studied 131 consecutive patients with non-obstructive CAD undergoing one-day rest-stress 13N-ammonia PET myocardial perfusion imaging (MPI). TID was automatically generated using CardIQ Physio software. The receiver operative characteristic (ROC) curve was used to determine the optimal threshold of TID. The follow-up outcome was major adverse cardiac events (MACE), a composite of re-hospitalization for heart failure or unstable angina, late revascularization, non-fatal myocardial infarction, and cardiac death. Cardiac event-free survivals for normal and abnormal TID were compared using Kaplan–Meier plots and log-rank tests. Results During a median follow-up of 42.08 ± 17.67 months, 22 (16.7%) patients occurred MACE. The optimal cut-off value of TID was 1.03 based on MACE. Our preliminary outcome analysis suggests that TID-abnormal subjects had a lower overall survival probability. Furthermore, our multivariate analysis reveals abnormal TID was the only independent predictor for MACE in non-obstructive CAD. In the subgroup analysis, an abnormal TID was an independent predictor for MACE in patients with abnormal perfusion patterns. Conclusion Among patients with non-obstructive CAD, PET-derived TID ≥ 1.03 may identify those with a high risk of subsequent MACE independently. It was also an independent risk factor for poor prognosis in patients with abnormal perfusion. Graphical abstract CAD coronary artery disease, PET positron emission tomography, MPI myocardial perfusion imaging, TID transient ischaemic dilatation, MACE major adverse cardiac events, ROC receiver operative characteristic.

Perfusion Abnormalities on 24-Hour Perfusion Imaging in Patients With Complete Endovascular Reperfusion.

Perfusion abnormalities in the infarct and salvaged penumbra have been proposed as a potential reason for poor clinical outcome (modified Rankin Scale score >2) despite complete angiographic reperfusion (Thrombolysis in Cerebral Infarction [TICI3]). In this study, we aimed to identify different microvascular perfusion patterns and their association with clinical outcomes among TICI3 patients. University Hospital Bern's stroke registry of all patients between February 2015 and December 2021. Macrovascular reperfusion was graded using the TICI scale. Microvascular reperfusion status was evaluated within the infarct area on cerebral blood volume and cerebral blood flow perfusion maps obtained 24-hour postintervention. Primary outcome was functional independence (90-day modified Rankin Scale score 0-2) evaluated with the logistic regression analysis adjusted for age, sex, and 24-hour infarct volume from follow-up imaging. Based on microvascular perfusion findings, the entire cohort (N=248) was stratified into one of the 4 clusters: (1) normoperfusion (no perfusion abnormalities; n=143/248); (2) hyperperfusion (hyperperfusion on both cerebral blood volume and cerebral blood flow; n=54/248); (3) hypoperfusion (hypoperfusion on both cerebral blood volume and cerebral blood flow; n=14/248); and (4) mixed (discrepant findings, eg, cerebral blood volume hypoperfusion and cerebral blood flow hyperperfusion; n=37/248). Compared with the normoperfusion cluster, patients in the hypoperfusion cluster were less likely to achieve functional independence (adjusted odds ratio, 0.3 [95% CI, 0.1-0.9]), while patients in the hyperperfusion cluster tended to have better outcomes (adjusted odds ratio, 3.3 [95% CI, 1.3-8.8]). In around half of TICI3 patients, perfusion abnormalities on the microvascular level can be observed. Microvascular hypoperfusion, despite complete macrovascular reperfusion, is rare but may explain the poor clinical course among some TICI3 patients, while a detrimental effect of hyperperfusion after reperfusion could not be confirmed.

Brain perfusion alterations in patients and survivors of COVID‐19 infection using arterial spin labeling: A systematic review

AbstractCoronavirus disease (COVID‐19) has been shown to impact the central nervous system, leading to various neurological complications. Arterial spin labeling (ASL), a non‐invasive magnetic resonance imaging technique, enables the measurement of cerebral blood flow and perfusion abnormalities. This systematic review aims to synthesize ASL findings in patients with COVID‐19 and assess the potential role of ASL in diagnosing and managing neurological complications. A comprehensive search was conducted on PubMed and Scopus for studies related to ASL in individuals with COVID‐19 or post‐COVID‐19 syndrome published between December 2019 and August 2024. Extracted data encompassed study characteristics, ASL protocols, cognitive assessments, and principal findings. The most consistent observation across studies was hypoperfusion detected in various brain regions, particularly within the frontal lobes, which may correlate with cognitive impairment and olfactory dysfunction. Additionally, some investigations reported hyperperfusion localized to the leptomeninges. These results may reflect underlying mechanisms such as hypoxic–ischemic injury, inflammation, vascular dysfunction, and neuronal damage attributable to COVID‐19. In conclusion, ASL has emerged as a valuable tool for evaluating brain perfusion among patients affected by or recovering from COVID‐19 since it offers critical insights into cerebral hemodynamics and metabolism. Further research is warranted to validate these ASL findings and elucidate whether post‐COVID‐19 syndrome contributes to persistent brain perfusion issues.

Abstract P130: Predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions

Objective: Optical coherence tomography (OCT) is an intravascular imaging technology that can provide cross-sectional images of coronary arteries, which can more accurately assess the condition of coronary artery lesions and the degree of vascular stenosis. It is an important method for the anatomical evaluation of coronary artery lesions. Radionuclide myocardial perfusion imaging (MPI) is a commonly used non-invasive method for functional evaluation of myocardial ischemia in clinical practice. The clinical application of these two methods is greatly limited due to operational risk and high cost. This study aimed to explore the potential predictive value of the MCG-based Nomogram model for the anatomical and functional evaluation of coronary artery lesions. Methods: We reviewed the patients who were hospitalized in the cardiovascular department of our hospital from October 2021 to July 2023 for MCG test. A total of 137 patients were included in the OCT subgroup, including 48 patients in the severe coronary artery stenosis group (inclusion criteria: OCT showed coronary artery area stenosis ≥70.0%) and 89 patients in the control group (inclusion criteria: OCT showed coronary artery area stenosis &lt;50.0% or CCTA showed no coronary artery stenosis). A total of 46 patients were included in the MPI subgroup, including 10 patients in the severe myocardial ischemia group (inclusion criteria: MPI showed abnormal perfusion scores of at least one ventricular segment ≥3 points) and 36 patients in the control group (inclusion criteria: MPI showed abnormal perfusion scores of all ventricular segments ≤2 points). The Nomogram model was used to predict the results of patients in the two subgroups, and the results were compared with the OCT and MPI results. The sensitivity, specificity and Youden index were calculated. Results: The Nomogram model based on MCG had a sensitivity of 70.8%, a specificity of 85.4%, and a Youden index of 0.562 for predicting OCT results. The sensitivity, specificity and Youden index of Nomogram model for predicting MPI results were 70.0%, 72.2% and 0.422, respectively. Conclusions: The MCG-based Nomogram model has good prediction accuracy for the anatomical and functional evaluation of coronary artery lesions, which has potential application value.