Ring Sign Research Articles

Association between coronary inflammation measured by FAT attenuation index and CT features of atheromatous plaque vulnerability

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This research has been funded by the research grant Intel-FAT, proposal registration code PN-III-P4-ID-PCE-2020-2861, contract number PCE 206/2021, Project funded by the European Union and the Government of Romania through the Ministry of European Funds, and the Doctoral School of the “George Emil Palade” University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, Romania. Background Coronary computed tomography angiography (CCTA) is a rapidly evolving tool for the assessment of coronary artery disease (CAD), being able to characterise not only the degree of coronary artery stenosis but also the presence and severity of coronary plaque vulnerability. Fat attenuation index (FAI) is a recently developed marker of coronary inflammation, based on the gradient of CT density at the level of pericoronary fat. Purpose The aim of our study is to investigate the correlation between (1) coronary inflammation as assessed by FAI score, and (2) vulnerability degree of atheromatous coronary plaques, as assesses by presence and severity of CT features of vulnerability at the level of coronary plaques. Methods A total of 54 patients who underwent 128-slice CCTA for chest pain, and having at least one vulnerable coronary plaque, were enrolled in the study. Vulnerable plaques were defined as plaques showing at least one of the following on CT scan: low attenuation plaque, napkin-ring sign, spotty calcifications, or positive remodeling. In total, 114 vulnerable plaques were identified and analyzed using the advanced via Syngo.via Frontier software. FAI score was determined using the FAI technology patented by Caristo. Results The FAI score of coronary inflamamtion was significantly correlated with the total plaque volume at the level of left anterior descendent artery (LAD) (p = 0,01), respectively with the calcified plaque volume at the level of the circumflex artery (p = 0,02). Receiver operating characteristic (ROC) analysis for the correlation between the FAI score and the presence of the Napkin Ring Sign (NRS) showed a significant correlation for plaques located on LAD (AUC 0,729; 95%CI 0,585 – 0,845; p = 0,01), and lefty circumflex artery (AUC 0,745; 95%CI 0,601–0,859; p = 0,032), but not for the right coronary artery (AUC 0,636; 95%CI 0,487–0,767; p = 0,25). Furthermore, the ROC analysis identified a good correlation between the FAI score and the presence of spotty calcification or positive coronary remodeling (AUC 0,777, p = 0,0004, respectively AUC 0,717, p = 0,0081). Conclusion Coronary inflammation measured by FAT attenuation index is significantly correlated with the presence of CT vulnerability features in the coronary tree.

Associations between the serum triglyceride-glucose index and pericoronary adipose tissue attenuation and plaque features using dual-layer spectral detector computed tomography: a cross-sectional study.

The triglyceride-glucose (TyG) index is a reliable alternative marker for insulin resistance (IR). Pericoronary adipose tissue (PCAT) can indirectly reflect coronary inflammation. IR and coronary inflammation play a key role in the development and progression of coronary atherosclerosis. Therefore, this study investigated the relationships between the TyG index, PCAT and atherosclerotic plaque characteristics to explore whether IR might lead to coronary artery atherosclerosis progression by inducing coronary inflammation. We retrospectively collected data on patients with chest pain who underwent coronary computed tomography angiography using spectral detector computed tomography at our institution from June to December 2021. The patients were grouped based on their TyG index levels: T1 (low), T2 (medium), and T3 (high). Each patient was assessed for total plaque volume, plaque load, maximum stenosis, the plaque component volume proportion, high-risk plaques(HRPs), and plaque characteristics (including low attenuation plaques, positive remodeling, a napkin ring sign, and spot calcification). PCAT quantification was performed on the proximal right coronary artery using the fat attenuation index (FAI) measured from a conventional multicolor computed tomography image (FAI120kVp), a spectral virtual single-energy image (FAI40keV), and the slope of the spectral HU curve (λHU). We enrolled 201 patients. The proportion of patients with maximum plaque stenosis, positive remodeling, low-density plaques, and HRPs increased as the TyG index level increased. Moreover, the FAI40keV and λHU significantly differed among the three groups, and we identified good positive correlations between FAI40keV and λHU and the TyG index (r = 0.319, P <0.01 and r = 0.325, P <0.01, respectively). FAI120kVp did not significantly differ among the groups. FAI40keV had the highest area under the curve, with an optimal cutoff value of -130.5 HU for predicting a TyG index value of ≥9.13. The multivariate linear regression analysis demonstrated that FAI40keV and λHU were independently positively related to a high TyG index level (standardized regression coefficients: 0.117 [P <0.001] and 0.134 [P <0.001], respectively). Patients with chest pain and a higher TyG index level were more likely to have severe stenosis and HRPs. Moreover, FAI40keV and λHU had good correlations with the serum TyG index, which may noninvasively reflect PCAT inflammation under insulin resistance. These results could help explain the mechanism of plaque progression and instability in patients with insulin resistance might be related to IR-induced coronary inflammation.

Computed Tomography Assessment of Coronary Atherosclerosis: From Threshold-Based Evaluation to Histologically Validated Plaque Quantification.

Arterial plaque rupture and thrombosis is the primary cause of major cardiovascular and neurovascular events. The identification of atherosclerosis, especially high-risk plaques, is therefore crucial to identify high-risk patients and to implement preventive therapies. Computed tomography angiography has the ability to visualize and characterize vascular plaques. The standard methods for plaque evaluation rely on the assessment of plaque burden, stenosis severity, the presence of positive remodeling, napkin ring sign, and spotty calcification, as well as Hounsfield Unit (HU)-based thresholding for plaque quantification; the latter with multiple shortcomings. Semiautomated threshold-based segmentation techniques with predefined HU ranges identify and quantify limited plaque characteristics, such as low attenuation, non-calcified, and calcified plaque components. Contrary to HU-based thresholds, histologically validated plaque characterization, and quantification, an emerging Artificial intelligence-based approach has the ability to differentiate specific tissue types based on a biological correlate, such as lipid-rich necrotic core and intraplaque hemorrhage that determine plaque vulnerability. In this article, we review the relevance of plaque characterization and quantification and discuss the benefits and limitations of the currently available plaque assessment and classification techniques.

Eight-and-a-half syndrome as the first presentation of multiple sclerosis in an Asian male: a case report

BackgroundMultiple sclerosis is a diffuse chronic demyelinating disease of the central nervous system. It is relatively uncommon in the Asian population and even more so in males. Despite the usual involvement of the brainstem, eight-and-a-half syndrome remains a rare first presentation in multiple sclerosis. Only a few cases have been reported previously, but none involving the Asian population. Eight-and-a-half syndrome, a neuro-ophthalmological condition, is characterized by one-and-a-half syndrome with ipsilateral lower facial nerve palsy, which localizes lesions to the pontine tegmentum. This case report demonstrates the first case of eight-and-a-half syndrome as the first presentation of multiple sclerosis in an Asian male.Case presentationA healthy 23-year-old Asian man presented with sudden onset of diplopia followed by left-sided facial asymmetry for 3 days. Assessment of extraocular movement revealed left conjugate horizontal gaze palsy. On right gaze, there was limited left eye adduction and horizontal nystagmus of the right eye. These findings were consistent with a left-sided one-and-a-half syndrome. Prism cover test revealed left esotropia of 30 prism diopters. Cranial nerve examination showed left lower motor neuron facial nerve palsy, while other neurological examination was normal. Magnetic resonance imaging brain showed multifocal T2 fluid attenuated inversion recovery hyperintense lesions, involving bilateral periventricular, juxtacortical, and infratentorial regions. A focal gadolinium contrast-enhanced lesion with open ring sign on T1 sequence was seen at the left frontal juxtacortical region. Multiple sclerosis was diagnosed on the basis of the clinical and radiological evidence, which fulfilled the 2017 McDonald criteria. Positive oligoclonal bands in cerebrospinal fluid analysis further confirmed our diagnosis. He had a complete resolution of symptoms 1 month after a course of pulsed corticosteroid therapy, and was subsequently placed on maintenance therapy with interferon beta-1a.ConclusionThis case illustrates eight-and-a-half syndrome as the first presentation of a diffuse central nervous system pathology. A wide range of differential diagnoses needs to be considered in such a presentation as based on the patient’s demographics and risk factors.

Prevalence, diagnosis, and impact on clinical outcomes of dural ossification in the thoracic ossification of the ligamentum flavum: a systematic review.

Systematic review. Thoracic ossification of the ligamentum flavum (TOLF) has become the principal cause of thoracic spinal stenosis. Dural ossification (DO) was a common clinical feature accompanying with TOLF. However, on account of the rarity, we know little about the DO in TOLF so far. This study was conducted to elucidate the prevalence, diagnostic measures, and impact on the clinical outcomes of DO in TOLF by integrating the existing evidence. PubMed, Embase, and Cochrane Database were comprehensively searched for studies relevant to the prevalence, diagnostic measures, or impact on the clinical outcomes of DO in TOLF. All retrieved studies meeting the inclusion and criterion were included into this systematic review. The prevalence of DO in TOLF treated surgically was 27% (281/1046), ranging from 11 to 67%. Eight diagnostic measures have been put forward to predict the DO in TOLF using the CT or MRI modalities, including "tram track sign", "comma sign", "bridge sign", "banner cloud sign", "T2 ring sign", TOLF-DO grading system, CSAOR grading system, and CCAR grading system. DO did not affect the neurological recovery of TOLF patients treated with the laminectomy. The rate of dural tear or CSF leakage in TOLF patients with DO was approximately 83% (149/180). The prevalence of DO in TOLF treated surgically was 27%. Eight diagnostic measures have been put forward to predict the DO in TOLF. DO did not affect the neurological recovery of TOLF treated with laminectomy but was associated with high risk of complications.

Onion ring sign on spectral domain optical coherence tomography in diabetic macular edema: Its evolution and outcomes.

To report evolution and outcomes of hyperreflective crystalline deposit (HCD) on optical coherence tomography (OCT) in diabetic maculopathy (DM). Patients with DM showing HCD on OCT for the first time between June 2017 and May 2021 were included in the study. Demographic, ophthalmic and OCT features were documented and analysed. Factors leading to the development of HCD and its effect on the functional outcome were analysed and described in this study. Sixty cases of HCD were identified in 45 (males -33; females - 12) patients for the first-time during the defined study period. Mean age of the eligible patients was 61.53 ± 8.19 years. Average duration of diabetes was 13.82 ± 7.38 years. Mean visual acuity of these patients was 0.902 ± 0.438 logMAR units (Snellen equivalent = 20/160). Patients with HCD showed subretinal hard exudates, were on anti-cholesterol medications (n = 36, 80%) and showed reduced visual acuity (20/160) if the HCD involved the fovea. The median time taken for the development of HCD was 28 months. Mean follow-up duration of the study was 26.19 ± 27.98 months. Persistence of HCD in all cases (n = 42, 100%) was noted at the last follow-up visit. Horizontal, single or multi-layered HCDs on OCT in DM represent intraretinal or subretinal cholesterol crystal precipitates evolving from the hard exudates identical to the "onion ring sign" seen in neovascular AMD. HCDs or CCs depict deranged lipid metabolism, chronic vascular leakage and can lead to substantial visual impairment if the fovea gets involved.

Cough, with a sac of marbles in the chest.

A 48-year-old male patient presented with productive cough, dyspnea and abdominal pain of 2 months duration. He was diagnosed with diabetes mellitus 6 months ago and had not been regular with his medications. Clinical examination revealed a respiratory rate of 18 per min with room air saturation of 95%, and a paucity of movements with bronchial breath sounds identified on inspection and auscultation, respectively, over the right hemithorax. Chest skiagram and computed tomography images of his thorax are shown below [Figure 1].Figure 1: (a) shows chest skiagram and (b–d) shows high-resolution computed tomography images of the chest. A description of the images is in the accompanying textQuestion: What is the diagnosis? Answer: Pulmonary and hepatic hydatid disease. DISCUSSION The chest skiagram [Figure 1a] revealed a well-defined round radio-opacity in the right mid zone with a crescentic hyperlucent medial margin, called the crescent sign (white arrow). Figure 1b is a coronal view of high-resolution computed tomography (HRCT) scan of the chest lung window, which shows a large cyst in the right lung, with multiple small rounded opacities with fluid attenuation, some of which appear to be floating within it, appearing like a sac of marbles. This is consistent with a diagnosis of a hydatid cyst with multiple daughter cysts within it. There are pockets of air seen between the outer pericyst and inner endocyst, aptly named ‘air-crescent sign’ (blue arrow) and ‘signet ring sign’ (red arrow), which suggest a ruptured or complicated hydatid cyst. Figure 1c, the sagittal section of the HRCT scan of the chest lung window at the level of the aortic outflow tract, shows the ruptured hydatid cyst in the right lung. The daughter cysts have collected in the dependent area of the larger cyst, with some appearing to ‘rise’ over the rest, or the ‘rising-sun sign’ (blue arrow). Also seen is a small air pocket inferiorly (red arrow) between the pericyst and endocyst, called the ‘air-bubble sign’. The presence of air on either side of the endocyst (red arrowheads) gives the appearance of an ‘onion-peel sign’, or the ‘cumbo sign’. Figure 1d shows a large well-defined homogenous cyst in the right lobe of the liver.[1] Blood investigations revealed uncontrolled blood sugar levels. Armed with the characteristic radiology above, and supplemented by a positive serum latex agglutination test for Echinococcus antigen, he was diagnosed with pulmonary and hepatic hydatid disease. He was started on oral albendazole and subsequently underwent pericystectomy of lung cyst along with partial pericystectomy of cyst in the liver. Post-surgery, he is at present asymptomatic and is on regular follow-up. Hydatid disease is a zoonosis, commonly caused by the accidental ingestion of ova of the tapeworm Echinococcusgranulosus, which subsequently develop into larvae in the host intestine and migrate to other parts of the body where they develop into embryos, with the liver and lung being the most commonly involved organs.[1] Characteristic thoracic radiology should lead clinicians to suspect pulmonary hydatid disease, especially when dealing with patients with non-resolving pneumonia or lung mass. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

A case of retrograde intussusception due to transverse colon cancer detected by abdominal ultrasonography

A 78-year-old female patient presented to our hospital with abdominal pain and melena. Abdominal ultrasonography detected a multiple concentric ring sign and retrograde invagination mass near the hepatic flexure. Colonoscopy revealed a 40-mm diameter type 1 tumor in the transverse colon near the splenic flexure, and the biopsy specimen demonstrated a well-differentiated adenocarcinoma. Retrograde intussusception due to transverse colon cancer was diagnosed, and laparoscopic transverse colon resection with lymph node dissection was performed. The resected specimen revealed a 48×40mm diameter type 1 tumor in the transverse colon and was diagnosed as pT2N0M0 pStage I. Contrast-enhanced computed tomography was unavailable, but real-time assessment of the invaginated mass and bowel blood flow was possible by abdominal ultrasonography, which was useful in determining the diagnosis and treatment strategy.

Evaluation of neurologically symptomatic and asymptomatic patients in childhood Wilson's disease with central nervous system involvement: A retrospective observational study

Abstract Objective: The aim was to evaluate the clinical and laboratory characteristics of children with Wilson's disease (WD) with and without neurological presentation with abnormalities on brain magnetic resonance imaging (MRI) and to describe the relationship of these observations with disease severity and functional outcome and their impact on prognosis. Materials and methods: Demographic, neuropsychiatric findings, laboratory, disease severity and functional results of 48 children with neurologically symptomatic and asymptomatic WD were evaluated retrospectively. Results: A significant positive correlation was found between the neurologic symptom score and functional outcome in WD with neurological presentation (p &lt;0.001). A significant positive correlation was found between disease severity scores (PELD, MELD, Child Pugh and Dhwin score) and modified Rankin scores (mRS) in WD without neurological presentation (p &lt;0.001, 0.004, &lt;0.001, 0.001, respectively). In addition, a significant positive correlation was found between total bilirubin, direct bilirubin and Internationel Normalized Ratio (INR) values and mRS scores (p= 0.006, 0.012, 0.004, respectively). Kayser-Fleischer Ring sign in the eye was higher in the group with neurological symtomatic WD (p &lt;0.001). The number of patients presenting with clinic of fulminant hepatitis and hepatic encephalopathy was significantly higher in the neurological asymptomatic group (p &lt;0.001) Conclusion: Brain MRI changes may occur even in hepatic WD and presymptomatic cases, although infrequently, regardless of the presence of neurological symptoms. It should be known that neurological symptoms in children and adolescents may occur without significant liver disease. Even without neurological symptoms, all children with WD should have a brain MRI before treatment.

BRONCHIECTASIS: MICROBIOME AND INFECTIONS

Due to the degradation of the muscles and elastic connective tissues, bronchiectasis is characterized by a chronic enlargement of the bronchi and bronchioles. The condition is characterized by an ongoing cough, the production of sputum, and infections and can strike at any age. Bronchiectasis may have been less frequent in the 20th century, but it still ranks third among the chronic inflammatory disorders of the airways, behind chronic obstructive pulmonary disease and asthma. Pseudomonas aeruginosa and Haemophilus influenzae are the most frequent bacteria detected in bronchiectasis airways worldwide, but proportions differ amongst bacterial communities. Additionally, Streptococcus, Prevotella, Veillonella, and Staphylococcus have been found in bronchiectasis patients' airways. The symptoms of bronchiectasis, which include worsened sputum production with more blood and purulent discharge, wheezing and dyspnea, as well as fever, are considered to be brought on by bacterial infection. On thin-section CT scans, morphologic criteria include the presence of bronchi within 1 cm of the pleural surface and bronchial dilatation in relation to the adjacent pulmonary artery (signet ring sign). The basic objectives of bronchiectasis care are to preserve adequate lung function, regulate symptoms and enhance patient quality of life while preventing and reducing exacerbations.

Evaluating anemia on non-contrast thoracic computed tomography

Anemia is a major global disease burden factor linked to an adverse impact on overall prognosis and negatively affects the quality of life. There are some suggested findings for anemia on non-contrast chest CT, like relatively dense interventricular septum (septal sign) or fairly dense aortic wall (aortic ring sign). The measured attenuation value is a reproducible physical density measurement, readily obtainable from a standard CT examination. There is no reliable cut-off for blood attenuation to suggest anemia on the non-contrast chest CT. In the current study, we evaluated subjective and objective criteria' diagnostic accuracy for diagnosing anemia on unenhanced thoracic CT. This study is approved by Mashhad University of Medical Sciences. The patients admitted in the internal medicine ward of our hospital from June 2019 to March 2020 for whom a non-contrast chest CT was acquired for any non-traumatic medical indication, were enrolled in this retrospective study. For the subjective assessment, the radiologists were asked to record the presence or absence of the "aortic ring sign" and "interventricular septum sign". For the objective evaluations, blood density was measured at various anatomic locations. A total of 325 patients were included in this study. There was a significant correlation between blood attenuation in all measured segments and Hb level (0.78 (R2: 0.61), p = 0.000). Findings revealed that considering the aortic arch threshold value as 20 HU is the best diagnostic performance for detecting severe anemia. Subjective analysis revealed that the aortic ring sign was more sensitive (82.5%) than the interventricular septum sign (32%) in detecting anemia, whereas the latter character was more specific (87% and 99.2%, respectively). The results suggest that it is possible to detect anemia from an unenhanced chest CT scan. Both objective and subjective criteria show promising sensitivity and specificity.

Epiploic appendagitis

Paediatric abdominal pain continues to pose a diagnostic challenge in the acute hospital care setting. We describe an eleven-year-old boy who presented to the emergency department with acute-onset, sharp abdominal pain localised to right lower quadrant. Abdominal imaging was diagnostic for epiploic appendagitis (EA), with pathognomonic 'ring sign' and 'central dot' visualised on the axial computed tomography images. He responded well to conservative treatment, including a short course of non-steroidal anti-inflammatory drugs. EA is a lesser-known paediatric entity mimicking surgical conditions. However, steady but sharp and non-migratory characteristic of the pain in either of the lower abdominal quadrants should raise suspicion for EA. Early accurate diagnosis can prevent unnecessary surgical exploration in these patients.

'Ring sign' of pheochromocytoma.

'Ring sign' of pheochromocytoma.

Wrist angle measurements in predicting the presence of a displaced scaphoid fracture.

Early diagnosis and treatment of scaphoid fractures is critical to achieve union and prevent wrist degenerative arthritis. Plain radiographic measurements can guide the early approach to suspected fractures. Specifically, the ability to predict fracture or fracture stability from plain radiographs may allow the traumatologist to expand initial referral to three-dimensional imaging. We evaluated the ability of four measured angles to predict presence of a scaphoid fracture and stability. Fifty patients with a scaphoid fracture and 50 patients without fracture were evaluated for the cortical ring sign, scapho-lunate gapping, lateral scapholunate (SL), radio-scaphoid (RS), radio-lunate (RL), and radio-capitate (RC) angles by two-blinded observers. Measurement of an increased SL interval was associated with the presence of a scaphoid fracture as diagnosed on three-dimensional imaging [odds ratio (OR) 3.0, confidence interval (CI) 1.53-5.87, p = < 0.01]. The measured RL angle was associated with fracture displacement (OR 1.13, 95% CI 1.02-1.25, p = 0.02). Scapholunate gapping on plain radiographs in the context of a clinically suspected scaphoid fracture should increase suspicion for a fracture and may prompt earlier 3-dimensional imaging, while the presence of an abnormal radiolunate angle should increase wariness for instability and can be used in preoperative planning.

Ganglión en el túnel del tarso: ¿localización intra o extraneural?

Intraneural ganglion cysts are very uncommon lesions that are starting to be diagnosed thanks to the establishment of the articular theory to explain their pathogenesis and to the definition of their signs on magnetic resonance imaging (MRI). We present the case of a 59-year-old man with clinical findings suggestive of tarsal tunnel syndrome. MRI of the ankle and foot showed an intraneural ganglion cyst involving the posterior tibial nerve and its connection with the subtalar joint through an articular nerve branch. The appropriate interpretation of specific radiologic signs such as the “signet ring sign” enabled an appropriate preoperative diagnosis to be established, differentiating it from an extraneural lesion and facilitating the articular disconnection of the nerve branch during surgery.

MR Imaging Findings of Carcinoma Ex Pleomorphic Adenoma Related to Extracapsular Invasion and Prognosis.

MR imaging can reflect the pathologic progression of carcinoma ex pleomorphic adenoma (CXPA). This study aimed to identify the imaging findings related to extracapsular invasion of CXPA. Additionally, the pathologic background of these findings was investigated. This retrospective study included 37 patients with histologically confirmed CXPA. Three radiologists independently evaluated whether the CXPA showed the following characteristic MR imaging findings: border, capsule, the corona sign on fat-saturated T2WI and contrast-enhanced fat-saturated T1WI, and the black ring sign. The corona sign appeared larger on fat-saturated and/or contrast-enhanced fat-saturated T1WI than on T1WI. The black ring sign was defined as an intratumoral nodule with a thick low-intensity rim on T2WI. Interreader agreement of the visual assessment was performed using κ analysis, and MR imaging and histopathologic findings were also correlated. Kaplan-Meier survival and the log-rank test were used to estimate the 3-year disease-free survival. MR imaging findings, especially peritumoral findings, showed a significant difference between invasive and noninvasive CXPA. The reliability was poor for the border and capsule. In contrast, it was good for the corona sign on fat-saturated and contrast-enhanced fat-saturated T1WI and the black ring sign. Pathologically, the corona sign reflected the invasiveness of the tumor and inflammatory cells, while the black ring sign reflected hyalinization or fibrosis. The corona sign also showed a significant difference in the 3-year disease-free survival. MR imaging findings, including the corona and black ring signs, reliably differentiated invasive and noninvasive CXPA. The corona sign can be used as a prognostic factor for CXPA.

Prevalence and culprit lesion plaque characteristics on optical coherence tomography in patients with non-st-segment elevation acute coronary syndrome with zero coronary calcification on coronary CTA

Abstract Background CAC evaluated by non-contrast computed tomography is a marker of atherosclerosis. However, the characteristic features of CCTA and optical coherence tomography (OCT) of culprit lesions in patients with NSTE-ACS showing zero CAC remain unknown. Objectives This study aimed to assess the prevalence and characteristic features of culprit lesions on coronary CT angiography (CCTA) and optical coherence tomography (OCT) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) showing zero coronary artery calcium (CAC). Methods A total of 176 consecutive patients with NSTE-ACS who underwent preprocedural CCTA and OCT were studied. Patients were divided into two groups according to their CAC (zero-CAC and non-zero-CAC groups). Baseline characteristics, CCTA and OCT findings were compared between these two groups. Results The prevalence of patients with zero-CACS was 15.9% (28/176). Patients in zero CAC group were younger (mean age, 55 vs. 65 years, P&amp;lt;0.001) and had a lower prevalence of diabetes (10.7 vs 37.2%, P=0.012) than non-zero CAC group. In zero CAC group, the lower prevalence of napkin ring sign (3.5% vs. 28.4%, P=0.028), smaller LV mass index (77.7 vs. 83.9, P=0.04), lower prevalence on spotty calcification (0 vs. 83.8%, P&amp;lt;0.001), lower epicardial fat volume (111.3 vs. 142.6 cm3, P=0.025), and lower pericoronary adipose tissue attenuation (−71.5 vs. −70.2 HU, P=0.07) on CCTA were observed. On OCT, the frequency of plaque erosion (82.1 vs. 44.6%, P&amp;lt;0.001) was significantly higher in zero-CACS group. The prevalence of lipid-rich plaque (46.4 vs. 86.5%, P&amp;lt;0.001), thin-cap fibroatheroma (17.9 vs. 46%, P=0.006), macrophage accumulation (46.4 vs. 81.8%, P&amp;lt;0.001) and cholesterol crystal (7 vs. 41.9%, P&amp;lt;0.001) were all significantly lower in zero-CAC group. Conclusions Zero CAC NSTE-ACS was not rare. Zero-CAC NSTE-ACS was characterized by specific phenotypes defined by the combined assessment of CCTA and OCT. Further studies are warranted if these characteristics of NSTE-ACS on preprocedural imaging studies provide prognostic information or guidance of a specific therapeutic approach. Funding Acknowledgement Type of funding sources: None.

Epicardial and pericoronary fat volume and attenuation, lipid lowering therapy and coronary high risk coronary plaque burden

Abstract Background Epicardial (EAT) and pericoronary adipose tissue (PCAT) are known as risk predictors of subclinical atherosclerosis and coronary artery disease. We aimed to evaluate the association of EAT and PCAT volume and attenuation with the presence of high risk coronary plaque burden in patients with vs. without lipid lowering therapy. Methods In the present retrospective analysis a total of 321 patients undergoing coronary CTA at the XXX were included. EAT and PCAT were manually traced from CT imaging for assessment of fat volume and attenuation. According to the SCCT guidelines for the interpretation of coronary CTA, each coronary segment was evaluated for the presence of high risk plaque features (napkin ring sign, spotty calcification, positive remodeling, and low attenuation plaque). Results Overall data from 321 patients (mean age: 55.5±14.7 years, 62% male) and a total of 5778 coronary segments were included in our analysis. The cohorts consists of 116 patients without plaque and stenosis, 96 patients with plaque but no significant stenosis and 109 patients with obstructive coronary stenosis. Highest rates of the presence of coronary plaque were detected in proximal LAD (17.9%), followed by mid LAD (12.9%) and proximal RCA (10.8%). Coronary stenosis was also most common in proximal LAD (14.6%), followed by mid LAD (12.1%) and proximal RCA (11%). High risk plaque features were found in 401 segments and were most frequently located in the proximal LAD (21.4%). EAT volume increased with higher rates of stenosis and plaque (44.7±25.2ml vs. 68,2±28,5ml vs. 85.2±31.7ml, p&amp;lt;0.001). Prevalence of high risk plaque increased by higher EAT volume (OR [95% CI]: 3.17 [2.33–4.33], p&amp;lt;0.0001) and remains stable after upon adjustment for risk factors (2.32 [1.46–3.7], p&amp;lt;0.0001). EAT attenuation also significantly associated with the presence of high risk plaques with 0.68-folded risk in the unadjusted (0.68 [0.53–0.88], p=0.003), and 0.62-folded risk in the multivariate (MV) adjusted regression analysis (0.62 [0.45–0.85], p=0.003). However, for PCAT only its volume but not its attenuation was significantly associated with presence of high risk plaques in MV-adjusted regression analysis (PCAT volume: 2.25 [1.02–4.96], p=0.044; PCAT attenuation: 0.84 [0.63–1.12], p=0.24). Furthermore, patients receiving lipid-lowering therapy showed a significantly lower probability for high risk plaque detection (0.17 [0.14–0.21], p&amp;lt;0.0001). These findings remained stable after multivariate adjustment (0.27 [0.21–0.35], p&amp;lt;0.0001). Conclusion EAT volume and attenuation as well as PCAT volume associate with high risk plaques independent of traditional cardiovascular risk factors. In contrast, we found no significant association of PCAT attenuation with high risk coronary atherosclerosis. Our results encourage further research to evaluate the interplay of lipid-lowering therapy and EAT on plaque composition. Funding Acknowledgement Type of funding sources: None.

Identification of coronary plaque rupture or erosion by preprocedural computed tomography angiography in patients with non-st-segment elevation acute coronary syndrome

Abstract Background The frequent pathological cause of acute coronary thrombosis is plaque rupture or erosion. A previous CT angiographic study failed to discriminate OCT-defined intact fibrous cap culprit lesions (IFC lesions) from those with ruptured fibrous cap (RFC group) in patients with acute coronary syndrome (ACS) and chronic coronary syndrome. Objectives This study aimed to evaluate the diagnostic efficacy of preprocedural coronary CT imaging to identify optical coherence tomography (OCT)-defined plaque rupture or erosion at culprit lesions in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Methods Consecutive patients with suspected NSTE-ACS who underwent preprocedural non-contrast CT and CT angiography (CCTA) were studied. Patients with at least one lesion with more than 50% stenosis at the proximal segment on CCTA were subsequently assessed by invasive coronary angiography and OCT. ALL CT and OCT examination were performed within 24 hours from presentation. The diagnosis of intact fibrous cap or ruptured fibrous cap was made by OCT for the angiographically most severely stenosed lesion. Cases of ambiguous OCT diagnosis such as massive thrombosis or calcified nodule precluding the fibrous cap assessment were excluded from the final analysis. Results In the final analysis of 176 patients, OCT identified 87 RFC plaques and 89 IFC plaques for the culprit lesions, respectively. In IFC group, lower prevalence of diabetes mellitus (24.7% vs. 41.4%, P=0.025) and lower peak cardiac marker elevation (CPK, 159 vs. 272 U/L, P&amp;lt;0.001) were observed. On CT, the prevalence of low attenuation plaque, positive remodeling, napkin ring sign, spotty calcification, calcium score (CAC), and culprit vessel pericoronary adipose tissue attenuation (FAI) were all significantly low in IFC group. Multivariate regression analysis to predict IFC at culprit lesions revealed that the absence of low attenuation plaque, the absence of napkin ring sign, zero CAC, and low FAI were independent predictors of IFC. When stratified by the number of these 4 CT factors, the presence of IFC were stratified as 0%, 23.6%, 50%, 77.8%, and 100% (P&amp;lt;0.001), respectively. Adding non-contrast CT factor of zero CAC to the reference model including age, sex, DM, EF, low attenuation plaque, napkin ring sign, and FAI, can increase the incremental discriminatory and reclassification performance for the prediction of IFC (C-statistic 0.828 NRI: 0.37, 95% CI: 0.095–0.646, P=0.008 and IDI: 0.042, 95% CI: 0.012–0.071, P=0.005). Conclusions Preprocedural comprehensive CT imaging including CAC and pericoronary adipose tissue inflammation could identify IFC or RFC culprit lesions defined by OCT. Further studies are needed to confirm our preliminary results and if CT imaging in NSTE-ACS provides prognostic information or specific therapeutic approach such as conservative therapy or non-stenting strategy before invasive angiography. Funding Acknowledgement Type of funding sources: None.

Coronary plaque characteristics associated with major adverse cardiovascular events in atherosclerotic patients and lesions – a systematic review and meta-analysis

Abstract Background The clinical value of high-risk coronary plaque characteristics (CPCs) to inform intensified medical therapy or revascularization of non-flow-limiting lesion remains uncertain. Purpose We performed a systematic review and meta-analysis to study the prognostic impact of CPCs on patient-level and lesion-level major cardiovascular adverse events (MACE). Methods We systematically reviewed MEDLINE, EMBASE, and the Cochrane database for studies evaluating the association of CPC with patient-level and lesion-level MACE. CPCs included high plaque burden, low minimal lumen area, thin cap fibroatheroma, high lipid core burden index, low attenuation plaque, spotty calcification, napkin ring sign, or positive remodelling. Results Thirty studies (21 retrospective, 9 prospective) with 30,369 patients were included. CPCs were evaluated by invasive intravascular techniques in 9 studies (optical coherence tomography=4, intravascular ultrasound imaging=3, near-infrared spectroscopy intravascular ultrasound imaging=2) and by coronary computed tomography angiography (CCTA) in 21 studies. CPCs significantly predicted patient-level and lesion-level MACE in both unadjusted and adjusted analyses. For each CPC, the risks were higher for lesion-level (HR range 3.2–16.8) as compared with patient-level MACE (HR range 1.8–4.1). Accuracy was modest to good for most CPCs at the patient-level (AUC for MACE ranging between 0.53 and 0.84) and moderate to good for most CPCs at the lesion-level (AUC for MACE ranging between 0.71 and 0.83). Plaques with more than one CPC had the highest accuracy for lesion-level MACE (AUC 0.87, 95% CI 0.84–0.90). The pooled sensitivities of CPCs for lesion-level MACE ranged between 40% and 63% and specificities between 73% and 98%. As the pooled prevalence of CPCs among plaques was low (3% to 28%), the estimated positive predictive values for lesion-level MACE were modest (range 1% to 26%). Conclusions CCTA and intravascular imaging characterization of CPCs identifies high-risk atherosclerotic plaques that place lesions and patients at risk for future MACE, albeit with modest sensitivity and positive predictive value (PROSPERO identifier: CRD42021251810). Funding Acknowledgement Type of funding sources: None.