Multidetector-row Computed Tomography Research Articles

Impact of 18FDG Positron Emission Tomography - Computed Tomography (PET-CT) on Management of Gallbladder Carcinoma

Background: Reports concerning the clinical usefulness 18F-FDG PET-CT for patients with gallbladder cancer are relatively scarce. The purpose of this study was to assess the diagnostic value of 18FGD- PET-CT in relation to a conventional imaging modality, multidetector row CT (MDCT), for patients with gallbladder cancer. Materials and Methods: Seventy patients with suspected gallbladder cancer who underwent both PET-CT and MDCT for initial staging were included in our study. The results of these two imaging modalities for evaluating primary tumors, regional lymph nodes and distant metastases were compared with the final diagnoses based on histopathological examination. Change in management of patients with gallbladder cancer based on PET-CT was also evaluated. Results: A maximum standardized uptake value (SUVmax) of 5.37 was taken as cutoff value for detecting a malignant tumor. PET-CT demonstrated no significant advantage over MDCT for the diagnosis of a primary tumor. PETCT showed a significantly higher accuracy (90.8 vs. 80.0%, P = 0.04) than that found for MDCT in the diagnosis of regional lymph node metastasis. PET-CT showed higher sensitivity (92.3 vs. 61.5%, P = 0.04) than that found for MDCT in the diagnosis of distant metastasis. Addition of PET-CT in preoperative staging of the disease changed management in 10 patients (14.3%). Conclusions: In patients with gallbladder carcinoma, the addition of 18FDG-PET-CT to standard staging CT may be helpful in detecting distant nodal metastasis and unsuspected metastatic disease that may preclude patients from surgical resection and result in a change of management in a significant number of patients.

A novel method for predicting perineural invasion of distal cholangiocarcinoma on multidetector-row computed tomography.

Excessive perineural invasion (PNI) is associated with a high risk of radial margin (RM) positivity and a poor prognosis for patients with distal cholangiocarcinoma (DCC). This study evaluates a new method of predicting the extent of PNI preoperatively. The subjects of this retrospective study were 201 patients who underwent resection for DCC between 2002 and 2018. This study identified the 'periductal enation sign' (PES), defined as the surrounding soft tissue enhancement that appears as an enation from the circumference of the enhanced extrahepatic bile duct on multidetector-row computed tomography (MDCT) scans, as a predictor of PNI. We analyzed the outcomes of the patients in relation to the presence or absence of the PES on MDCT scans. The PES in the PNI-positive group was significantly longer than that in the PNI-negative group. As the length of the PES extended, the grade of PNI increased. A positive PES was defined as a PES length of ≥ 2.0mm. Patients with a positive PES were more frequently positive for RM (23.7% vs. 2.1%) and locoregional recurrence (23.7% vs. 6.3%) and exhibited significantly poorer overall survival than those with a negative PES (30.2% vs. 54.6% at 5years). The presence and extent of PNI can be predicted easily and effectively by the PES length. A positive PES was associated with poor local controllability and a poor prognosis.

Abstract 9596: Presence and Extent of Aortic Arch Plaques for the Prediction of Cardiovascular Outcomes in Patients with Suspected Coronary Artery Disease Undergoing Wide Volume Scanning Coronary Computed Tomography Angiography

Introduction: Wide volume scanning with 320-row multidetector CT coronary angiography (WVS-CCTA) enables comprehensive assessment of aortic arch together with coronary artery disease (CAD), without additional contrast media injection (Figure A-E). This study investigated prognostic implication of the presence and extent of aortic arch plaques (AAPs) and coronary high-risk plaque burden, as assessed by low-attenuation plaque (LAP) volume, on major cardiovascular events (MACE). Methods: This study consisted of patients with suspected CAD undergoing WVS-CCTA (n=529, mean age 64 yo, 57% of male). Conventional CCTA analysis included the assessment of coronary artery calcium score (CACS), obstructive CAD (diameter stenosis <50%), and %LAP volume (<30 HU). AAP score was defined as the sum of AAP thickness (0: no plaque, 1: <3 mm, 2: 3-5 mm, 3: > 5 mm) and AAP maximum angle (0: no plaque, 1: <120°, 2: 120-240°, 3: > 240°), resulting in a total of 0-6 point(s). The primary endpoint was a MACE composed of all-cause mortality, coronary revascularization, heart failure hospitalization, stroke, and vascular disease requiring invasive treatment. Results: The mean AAP score was 2.0 points (> 2 points in 56% and > 4 points in 27%), which is well correlated with CAD extent and severity. During a follow-up period of 2 years, MACE was observed in 15% of the study patients. In Cox hazard model analysis adjusted by age, gender, chronic kidney disease, and left ventricular ejection fraction <50%, the independent factors associated with MACE were diabetes mellitus [hazard ratio (HR), 1.9; p=0.009], obstructive CAD (HR, 3.8; p <0.001), the 4 th quartile of %LAP volume (HR, 1.8; p=0.016), and AAP score per 1 point increase (HR, 1.2; p=0.008). Conclusion: This study demonstrates unique opportunity for comprehensive evaluation of the presence and extent of AAPs together with CAD, providing prognostic implication of AAP score on MACE in patients with suspected CAD.

Variation in tube voltage for pediatric neck 64VCT: Effect on radiation dose and image quality

Exposure to ionizing radiation can cause cancer, especially in children. In computed tomography (CT), a trade-off exists between the radiation dose and image quality. Few studies have investigated the effect of dose reduction on image quality in pediatric neck CT. We aimed to assess the effect of peak kilovoltage on the radiation dose and image quality in pediatric neck multidetector-row CT. Measurements were made using three phantoms representative of children aged 1, 5, and 10 years, with tube voltages of 80, 100, and 120 kilovoltage peak (kVp); tube current of 10, 40, 80, 120, 150, 200, and 250 mA; and exposure time = 0.5 s (pitch, 0.984:1). Radiation dose estimates were derived from the dose-length product with a 64-multidetector-row CT scanner. Images obtained from the control protocol (120 kVp) were compared with the 80- and 100-kVp protocols. The effective dose (ED) was determined for each protocol and compared with the 120-kVp protocol. Quantitative analysis entailed noise measurements by recording the standard deviation of attenuation for a circular 1-cm2 region of interest placed on homogeneous soft tissue structures in the phantom. The mean noise of the various kVp protocols was compared using the unpaired Student t-test. Reduction of ED was 37.58% and 68.58% for neck CT with 100 kVp and 80 kVp, respectively. The image noise level increased with the decrease in peak kilovoltage. Noise values were higher at 80 kVp at all neck levels, but did not increase at 100 kVp, compared to 120 kVp in the three phantoms. The measured noise difference was the greatest at 80 kVp (absolute increases<2.5 HU). The subjective image quality did not differ among the protocols. Thus, reducing voltage from 120 to 80 kVp for neck CT may achieve ED reduction of 68.58%, without compromising image quality.

Assessing predictors of rheumatoid arthritis-associated interstitial lung disease using quantitative lung densitometry.

To assess predictors of subclinical RA-associated interstitial lung disease (RA-ILD) using quantitative lung densitometry (qLD). RA patients underwent multi-detector row CT scanning at baseline and after an average of 39 months. Scans were analysed with qLD for the percentage of lung parenchyma with high attenuation areas (%HAA: the percentage of voxels of -600 to -250 Hounsfield units). Additionally, a pulmonary radiologist calculated an expertradiologist scoring (ERS) for RA-ILD features. Generalized linear models were used to identify indicators of baseline %HAA and predictors of %HAA change. Baseline %HAA was assessed in 193 RA patients and 106 had repeat qLD assessment. %HAA was correlated with ERS (Spearman's rho = 0.261; P < 0.001). Significant indicators of high baseline %HAA (>10% of lung parenchyma with high attenuation) included female sex, higher pack-years of smoking, higher BMI and anti-CCP ≥200 units, collectively contributing an area under the receiver operator curve of 0.88 (95% CI 0.81, 0.95). Predictors of %HAA increase, occurring in 49% with repeat qLD, included higher baseline %HAA, presence of mucin 5B (MUC5B) minor allele and absence of HLA-DRB1 shared epitope (area under the receiver operator curve = 0.69; 95% CI 0.58, 0.79). The association of the MUC5B minor allele with %HAA change was higher among men and those with higher cumulative smoking. Within the group with increased %HAA, anti-CCP level was significantly associated with a greater increase in %HAA. %HAA, assessed with qLD, was linked to several known risk factors for RA-ILD and may represent a more quantitative method to identify RA-ILD and track progression than expert radiologist interpretation.

Epicardial Adipose Tissue Measured From Computed Tomography Predicts Cardiac Resynchronization Therapy Response in Patients With Non-ischemic Systolic Heart Failure.

Background: Epicardial adipose tissue (EAT) has been linked with the pathogenesis of heart failure (HF). Limited data have been reported about the clinical value of EAT for cardiac resynchronization therapy (CRT) in non-ischemic systolic HF. We aimed to explore the values of EAT measured from CT to predict the response to CRT in patients with non-ischemic systolic HF.Methods: Forty-one patients with CRT were consecutively recruited for our study. All patients received both gated resting Single Photon Emission CT (SPECT) myocardial perfusion imaging (MPI) and dual-source multi-detector row CT scans. EAT thickness was assessed on both the parasternal short and horizontal long-axis views. The area of EAT was calculated at the left main coronary artery level. Left ventricular systolic mechanical dyssynchrony (LVMD) was measured by phase standard deviation (PSD) and phase histogram bandwidth (PBW). The definition of CRT response was an improvement of 5% in left ventricular ejection fraction (LVEF) at 6 months after CRT implantation.Results: After 6 months of follow-up, 58.5% (24 of 41) of patients responded to CRT. A greater total perfusion deficit (TPD) was observed in the left ventricle, and a narrower QRS complex was observed in the nonresponse group than in the response group (p < 0.05). Meanwhile, the systolic PSD and systolic PBW were statistically greater in the CRT group with no response than in the response group (p < 0.05). Meanwhile, the baseline QRS duration, TPD, systolic PSD, systolic PBW, EAT thicknesses of the left ventricular (LV) apex, right atrioventricular (AV) groove, and left AV groove were all significantly related to the CRT response in the univariate logistic regression analysis. Furthermore, the QRS duration and EAT thicknesses of the right AV groove and left AV groove were independent predictors of CRT response in the multivariate logistic regression analysis.Conclusions: The EAT thickness of the left AV groove in patients with non-ischemic systolic HF is associated with the TPD of LV and LV systolic dyssynchrony. The EAT thickness of the AV groove has a good predictive value for the CRT response in patients with non-ischemic systolic HF.

Impact of tricuspid annular shape on late worsening tricuspid regurgitation after transcatheter aortic implantation: insight from multidetector row computed tomography assessment

Abstract Background Worsening of tricuspid regurgitation (TR) in patients undergoing transcatheter aortic valve implantation (TAVI) is associated with adverse clinical outcomes. The geometrical factors that determine the occurrence of significant TR after TAVI are uncertain. Multi-detector row computed tomography (MDCT) may provide additional geometrical insights in the pathophysiology of worsening TR after TAVI. Purpose To investigate the impact of right atrial and tricuspid annular (TA) geometryassessed by MDCT on the occurrence of significant TR (≥ moderate) at 1-year after TAVI. Methods Patients without significant TR who had undergone a full-beat MDCT prior to TAVI were included. Right and left atrial and ventricular volumes and TA parameters including the anterior-posterior (AP) and septal-lateral (SL) diameters, area and circularity (AP/SL ratio) were measured and correlated to the occurrence of significant TR at 1-year after TAVI. Results A total of 205 patients (80±7 years, 51% male) who underwent TAVI for severe aortic stenosiswere included. Moderate or severe TR at 1-year follow-up occurred in 59 patients (29%). Patients who developed significant TR were more likely to have atrial fibrillation and lower left ventricular (LV) volumes, but larger right and left atrial volumes and TA dimensions at baseline. After adjusting for atrial fibrillation and LV and right atrial volumes, larger end-diastolic TA SL diameter (odds-ratio 1.182 95% CI 1.047–1.334, P=0.007) and more circular TA shape were independently associated with the occurrence of significant TR. Conclusion In patients without significant TR prior to TAVI, TA dilation and loss of the elliptical shape of the TA at baseline are associated with of the occurrence of significant TR 1-year after TAVI. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): ESC research grant 2018 Representative cases

Sex differences in left ventricular remodeling in patients with severe aortic valve stenosis

Abstract Background Women with severe aortic valve stenosis (AS) have better long-term outcomes after transcatheter aortic valve implantation (TAVI) but worse survival after surgical aortic valve replacement compared to men. Whether this is related to sex differences in left ventricular (LV) remodeling is unknown. Purpose To examine sex differences in LV remodeling and outcomes in patients with severe AS undergoing TAVI. Methods Patients with severe AS who underwent TAVI between 2007 and 2018 with a pre-procedural multidetector row computed tomography (MDCT) scan were included. LV volumes, mass and function were analyzed with MDCT. Patients were classified into 4 LV remodeling patterns based on LV mass index and LV mass-to-volume ratio: 1) normal geometry, 2) concentric remodeling, 3) concentric hypertrophy and 4) eccentric hypertrophy. The primary endpoint was all-cause mortality after TAVI. Results A total of 289 patients (age 80±6 years, 54% male) were included. Women showed smaller LV volumes and mass compared to men. Concentric hypertrophy (50%) was the most frequent pattern of LV remodeling followed by eccentric hypertrophy (33%), normal geometry (13%) and concentric remodeling (4%). Concentric remodeling was more frequently observed in men compared to women (91% vs. 9% respectively, p=0.011). However, no sex differences were observed in the remaining LV remodeling patterns (Figure 1). During a median follow-up of 3.8 (IQR 2.2–5.1) years after TAVI, 87 patients died. Women demonstrated better outcome after TAVI compared to men (log-rank χ2=4.29, p=0.038). The survival benefit of women over men was mainly present among patients with concentric hypertrophy (log-rank χ2=4.91, p=0.027, Figure 2). Conclusion LV concentric and eccentric hypertrophy are similarly observed in men and women with severe AS. Women demonstrated better outcome after TAVI as compared to men, particularly among those with LV concentric hypertrophy. However, the outcome benefit of females after TAVI seems not to be related to sex-differences in LV remodeling. Funding Acknowledgement Type of funding sources: None. Distribution of sex in LV remodelingAll-cause mortality after TAVI

HISTOPATHOLOGY AIDING IN THE DIAGNOSIS OF AN ATYPICAL CASE OF AORTIC DISSECTION

TOPIC: Cardiothoracic Surgery TYPE: Medical Student/Resident Case Reports INTRODUCTION: Aortic dissection (AD) often presents as acute severe chest or back pain and hemodynamic compromise[1,2]. Early and accurate diagnosis and treatment are crucial for survival. Multiple imaging modalities can be used to demonstrate the dissection, including Computed Tomographic Angiography (CTA), Magnetic Resonance Angiography (MRA), and Transesophageal Echocardiography (TEE). We present a case where a patient with atypical presentation of AD underwent multiple diagnostic studies with inconsistent results. CASE PRESENTATION: A 47-year-old male with history of hypertension, asthma, and tobacco use presented with sudden onset of left-hand numbness, tingling, and pain with associated changes of color in his hand. Patient had sensory deficits in the left hand and left big toe. A left upper extremity (LUE) venous duplex was unremarkable. CTA of the chest showed a filling defect in the right posterior ascending aorta suggestive of an intimal flap. Esmolol was initiated. TEE did not reveal AD. Heparin was initiated. Arterial Doppler of the LUE was negative for any atherosclerotic or thrombotic diseases or evidence of obstruction. The following day, the patient experienced crushing chest pain radiating to the back. Transthoracic echocardiogram showed filling defect in the ascending aorta. Patient was operated on emergently. Although a frank AD was not observed, a mobile pedunculated mass was reported. The affected segment of the aorta was resected and a graft was used for repair. Histopathology results showed focal adventitial hemorrhage and degenerative medial changes consistent with AD. DISCUSSION: In this case of atypical AD diagnosis was not made early due to atypical symptoms and inconclusive and inconsistent imaging studies. The definitive diagnosis was made through histopathology, as even the inspection at time of surgery was inconclusive for AD, given unusual gross appearance. Painless dissection is encountered only in 6.4% of cases [3]. Conventional CT scanning has a sensitivity of 83-95% but it drops to <80% in the ascending aorta[4-7]. MRA or TEE is typically performed next to confirm the diagnosis. Despite a sensitivity of 98%[8,9], TEE was unremarkable in this case. The features of the AD on histopathology, including the presence of the intimal tear, hemorrhage near the adventitial layer, and medial degeneration confirmed the diagnosis. In a recent large cardiovascular registry, >60% of cases of AD were first identified at autopsy[10,11]. CONCLUSIONS: This case represents a diagnostic challenge and highlights the possibility of uncommon presentation of AD, and the importance of taking the results of multiple imaging modalities into consideration to confirm the diagnosis. In this case, and due to unusual gross appearance during surgery, histopathology was necessary to confirm the diagnosis. It is extraordinarily rare to require histopathology to confirm diagnosis of AD at time of surgery. REFERENCE #1: 1.Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA 2000; 283:897 REFERENCE #2: 2. Evangelista A, Isselbacher EM, Bossone E, et al. Insights From the International Registry of Acute Aortic Dissection: A 20-Year Experience of Collaborative Clinical Research. Circulation 2018; 137:1846. 3. Fatima S, Sharma K. Painless Aortic Dissection-Diagnostic Dilemma With Fatal Outcomes: What Do We Learn?. J Investig Med High Impact Case Rep. 2017;5(3):2324709617721252. 4. Nienaber CA, von Kodolitsch Y, Nicolas V, et al. The diagnosis of thoracic aortic dissection by noninvasive imaging procedures. N Engl J Med 1993; 328:1. 5. LePage MA, Quint LE, Sonnad SS, et al. Aortic dissection: CT features that distinguish true lumen from false lumen. AJR Am J Roentgenol 2001; 177:207. REFERENCE #3: 6. Shiga T, Wajima Z, Apfel CC, et al. Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis. Arch Intern Med 2006; 166:1350. 7. Hayter RG, Rhea JT, Small A, et al. Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting. Radiology 2006; 238:841. 8. Moore AG, Eagle KA, Bruckman D, et al. Choice of computed tomography, transesophageal echocardiography, magnetic resonance imaging, and aortography in acute aortic dissection: International Registry of Acute Aortic Dissection (IRAD). Am J Cardiol 2002; 89:1235. 9. Hartnell G, Costello P. The diagnosis of thoracic aortic dissection by noninvasive imaging procedures. N Engl J Med 1993; 328:1637; author reply 1638. 10. Hosoda Y. [Pathology of aortic dissection]. Nihon Geka Gakkai Zasshi. 1996 Oct;97(10):873-8. 11. Huynh N, Thordsen S, Thomas T, Mackey-Bojack SM, Duncanson ER, Nwuado D, Garberich RF, Harris KM. Clinical and pathologic findings of aortic dissection at autopsy: Review of 336 cases over nearly 6 decades. Am Heart J. 2019 Mar;209:108-115. DISCLOSURES: No relevant relationships by Matthew Darrow, source=Web Response No relevant relationships by Muhammad Mufty, source=Web Response No relevant relationships by Pradyumna Tummala, source=Web Response

Role of Multi-detector Row (320) CT Coronary Angiography in Assessment of Coronary Stents in Comparison with Coronary Angiography

Role of Multi-detector Row (320) CT Coronary Angiography in Assessment of Coronary Stents in Comparison with Coronary Angiography

MISSED DIAGNOSIS OF ACUTE TYPE A AORTIC DISSECTION TREATED AS NON-ST ELEVATION MYOCARDIAL INFARCTION: A TEACHABLE MOMENT

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Acute type A aortic dissection (ATAAD) is a life threatening emergency, with a mortality rate of 1% to 2% per hour during the first 24 to 48 hours, reaching 75% at 2 weeks and 91% at 1 year, if left untreated. CASE PRESENTATION: A 35-year-old male, nonsmoker with a history of untreated hypertension (HTN), presented with sudden onset, severe, non-radiating, "twisting" mid-sternal chest pain. Initial vital signs showed an elevated blood pressure (BP) to 210/132 mmHg in both arms, heart rate 85 beats/minute, afebrile and arterial saturation of 100% on room air. He was in severe distress due to chest pain and sweating profusely. The cardiac examination did not reveal a murmur, rub or gallop, his radial pulse was regular, and equal bilaterally. Electrocardiogram (EKG) showed sinus rhythm with T-wave inversions in inferior and lateral leads. Initial work up was significant for an elevated creatine kinase (CK) 636 U/L (normal range < 200 U/L). Chest X-ray did not reveal cardiomegaly, mediastinal widening or infiltrates. CT aortic dissection including iliac arteries - chest, abdomen and pelvis with and without contrast was read as negative for dissection, aneurysm, pulmonary embolism or pericardial effusion. Subsequent labs were significant for up trending CK of 751 U/L (normal range < 200 U/L) and Troponin 0.42 ng/ml (normal range < 0.10 ng/ml). In view of rising cardiac biomarkers, dual anti-platelets and anticoagulants for acute coronary syndrome (ACS) were started. A transthoracic echocardiogram (TTE) was ordered which was performed 12 hours later and showed dissection flap in proximal ascending aorta, moderate eccentric aortic regurgitation, and bicuspid aortic valve. DISCUSSION: Some reports of CT scanning in acute dissection have reported sensitivities close to 100%, but false negative scans are well recognized. True sensitivity is likely lower at 94% to 100% and specificity around 77% to 100%. False negative results can be secondary to a reader's error or a true false negative image. Second imaging tests are frequently obtained in cases of suspected aortic dissection, with transthoracic or transesophageal echocardiography being the most commonly used modality. Point of Care Ultrasound (POCUS) has become commonplace in many critical care settings, studies have shown good sensitivity and specificity for the diagnosis of ATAAD [5]. This may allow the treating clinician to diagnose an acute aortic dissection at the point of care, avoiding the clinical and time dissociation inherent to consultative echocardiography. Intimal flap visualization has a sensitivity of 67-80% and a specificity of 99 - 100%. CONCLUSIONS: Our case is a reminder that the sensitivity of CTA to rule out acute aortic syndrome is not 100% and second diagnostic modality should be used if clinical suspicion is high. The pre-test probability of a diagnosis should dictate the type of imaging/testing warranted and its urgency. REFERENCE #1: Afifi RO, Sandhu HK, Leake SS, et al.: Determinants of Operative Mortality in Patients With Ruptured Acute Type A Aortic Dissection. Ann Thorac Surg. 2016, 101:64-71. 10.1016/j.athoracsur.2015.07.007 REFERENCE #2: Abbas A, Brown IW, Peebles CR, Harden SP, Shambrook JS: The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome. Br J Radiol. 2014, 87:20140354. 10.1259/bjr.20140354 REFERENCE #3: Wang Y, Yu H, Cao Y, Wan Z: Early Screening for Aortic Dissection With Point-of-Care Ultrasound by Emergency Physicians: A Prospective Pilot Study. J Ultrasound Med. 2020, 39:1309-15. 10.1002/jum.15223 DISCLOSURES: No relevant relationships by SYED ABBAS, source=Web Response No relevant relationships by Syeda Hamadani, source=Web Response No relevant relationships by Seth Koenig, source=Web Response, value=Honoraria Removed 05/16/2021 by Seth Koenig, source=Web Response No relevant relationships by Seth Koenig, source=Web Response, value=Honoraria Removed 05/16/2021 by Seth Koenig, source=Web Response No relevant relationships by Abeer Zeeshan, source=Web Response

PRE-OPERATIVE EVALUATION AND TUMOUR-NODE-METASTASIS STAGING OF GASTRIC CARCINOMA USING 16 SLICE MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY

OBJECTIVE: To evaluate pre-operative tumour-node-metastasis staging (TNM) staging, metastases status and detection of role of multidetector-row computed tomography (MDCT) in gastric carcinoma patients in Pakistan.&#x0D; METHODS: This cross-sectional study, spanned over 14 months (January 2018-February 2019), was conducted at Radiology Department of Kuwait Teaching Hospital. Sample size was 173. Patients, selected through non-probability consecutive sampling technique, irrespective of gender, aged over 18 years and having clinically and histopathologically diagnosed with gastric carcinoma were included in the study. MDCT of patients was done. SPSS Version-24 was utilized for data analysis. Chi-square test was applied with p-value ≤0.05 was considered significant.&#x0D; RESULTS: Out of total 173 patients with gastric carcinoma, 121 (69.9%) were males and 52 (30.1%) were females. Mean age of patients was 48.5±1.2 years. Majority of patients were in T4a stage (n=64; 37%) followed T4b, T3, T0, T1 &amp; T2 (24.9%, 17.3%, 11% and 9.8%) respectively. N0 stage with no nodal metastases was 40.5% followed by N1 stage (1-2 lymph nodes), N2 stage (3-6 lymph nodes), N3a stage (7-15 lymph nodes) and N3b stage (more than 15 lymph nodes) with 25.4%, 19.7%, 5.8% and 8.7% respectively. M1 stage with distant metastases was in 76 (43.9%) patients. Age and gender had insignificant association with TNM system (p&gt;0.05).&#x0D; CONCLUSION: Multi detector row computed tomography was effective in pre-operative evaluation and TNM staging of gastric carcinoma. Lymph node detection on MDCT can further be utilized for fine needle biopsies if required.

Sex differences in left ventricular remodelling in patients with severe aortic valve stenosis.

Women with severe aortic stenosis (AS) have better long-term outcome after transcatheter aortic valve implantation (TAVI) but worse survival after surgical aortic valve replacement compared with men. Whether this is related to sex differences in left ventricular (LV) remodelling is unknown. The aim of this study was to examine the sex differences in LV remodelling with multidetector row computed tomography (MDCT) and outcome in patients with severe AS undergoing TAVI between 2007 and 2018. A total of 289 patients (age 80 ± 6 years, 54% male) were included. LV volumes, mass, and function were analysed on pre-procedural MDCT scans. Women showed smaller LV volumes and mass compared with men. Patients were classified into four LV remodelling patterns: concentric hypertrophy (50%) was the most frequent pattern of LV remodelling followed by eccentric hypertrophy (33%), normal geometry (13%), and concentric remodelling (4%). Men showed more concentric remodelling compared with women (91% vs. 9%, respectively, P = 0.011). However, no differences were observed in the remaining LV remodelling patterns. During a median follow-up of 3.8 (IQR 2.2-5.1) years after TAVI, 87 (30%) patients died. Women demonstrated better outcome after TAVI compared with men (log-rank χ2 = 4.29, P = 0.038). No association was observed between the interaction of the LV remodelling patterns and sex with outcome. LV concentric hypertrophy and eccentric hypertrophy are similarly observed in men and women with severe AS but concentric remodelling was more common in men. Women demonstrated better outcome after TAVI when compared with men. The interaction between the LV remodelling patterns and sex was not associated with survival.

Detection of posterior superior alveolar artery using multi-detector row CT: a retrospective study focused on age-related changes.

The posterior superior alveolar artery (PSAA) is a branch of the maxillary artery that supplies the lateral sinus wall and overlying membrane. This artery is one among several arteries in which arterial damage during surgery can cause massive and fatal bleeding. The purpose of this study was to detect the PSAA using multi-detector row computed tomography (MDCT) by age. The present study was approved by our university ethics committee (EC19-010). The study included 230 patients (110 males, 120 females; ages 5-91years, average age 42.5years) who underwent MDCT of the jaw. The subjects were divided into two groups, one group in which the PSAA was observable and another in which the PSAA was not observable, to perform the Mann-Whitney U test. To perform the Tukey-Kramer multiple comparison test, the subjects were divided into the following ten groups depending on their age: 5-9years, 10-19years, 20-29years, 30-39years, 40-49years, 50-59years, 60-69years, 70-79years, 80-89years, and 90-91years. The PSAA was identified in 74.5% (5-91years) of the maxillary sinuses. The average age of subjects in whom the PSAA was observable was 33.4years, and the average age of subjects in whom the PSAA was not observable was 11.3years, indicating a significant difference between these two groups (p < 0.01). A comparison by age group showed a significant difference (p < 0.05). The detection ratio for the PSAA using MDCT increased with increasing age of the subject, reaching a high detection ratio of 94% in adults. This study has shown that MDCT is a very useful tool to observe the PSAA.

Identifying multiple swollen lymph nodes on preoperative computed tomography is associated with poor prognosis along with pathological extensive nodal metastasis in locally advanced gastric cancer

BackgroundAdvanced gastric cancer with extensive lymph node (LN) metastasis is associated with poor outcomes even after R0 gastrectomy. Although multi-detector row computed tomography (MDCT) is the basis of preoperative LN staging, the diagnostic accuracy of pathologically extensive LN metastasis detection by MDCT remains unsatisfactory. MethodsWe retrospectively evaluated diagnostic accuracy for pN2/3 disease by size and number of depicted LNs on MDCT in a single-center cohort of 421 patients with pT2-4 gastric carcinoma. The positive predictive value (PPV) was determined based on the number and short-axis diameter (SAD) of identified LNs, and oncological outcomes were also evaluated according to clinical LN status and pN categories. ResultsThe PPV for detecting pN2/3 disease rose with the SAD value cut-off for one LN, reaching 84.6% at 10 mm with no further increase at 15 mm. However, the SAD cut-off value plateaued at 8 mm (91.3%) when at least two measurable LNs were identified on MDCT. Patients with two measurable LNs with SAD≥8 mm had significantly poorer 5-year overall and recurrence-free survival than patients with fewer than two measurable LNs in the pN2-3 disease. On multivariate analysis, two measurable LNs with SAD≥8 mm was an independent prognostic factor for overall and relapse-free survivals. ConclusionLocally advanced gastric cancer with two measurable LNs with SAD≥8 mm on preoperative MDCT is highly associated with pN2/3 disease and poorer outcomes with upfront surgery. This criterion might be a reasonable indicator for identifying candidates for neoadjuvant treatment of advanced gastric cancer.

B-PO04-087 EFFECT OF OBESITY ON LEFT ATRIAL WALL SUBSTRATE IN PATIENTS WITH ATRIAL FIBRILLATION: INSIGHT INTO EPICARDIAL ADIPOSE TISSUE AND FATTY INFILTRATION

Obesity and epicardial adipose tissue fat (EAT) contributes to the progression of atrial fibrillation (AF). But, its effect on the left atrial (LA) wall substate is clinically unknown. This study aimed to assess the effect of obesity on the LA substrate. Of 23 AF patients who underwent an initial pulmonary vein isolation (PVI) were enrolled. The 320-row multidetector CT was performed within 2 weeks before PVI. The acquired CT images were transferred to a workstation. EAT was defined as -50 to -200 Hounsfield units (HU). We measured LA EAT volume, EAT thickness adjacent to the LA roof, CT values on the LA roof wall, and LA roof wall thickness using workstation (figure). We compared these parameters between AF patients with and without obesity (≥BMI 25 kg/m2). Both LA EAT volume and EAT thickness were significantly greater in obese group than in non-obese group (LA EAT volume, 50±13 vs. 24±9 ml, P<0.01; EAT thickness, 8.8±2.7 vs. 5.5±1.7 mm, P<0.01). There was a strong positive correlation with LA EAT volume and EAT thickness (r=0.89, P<0.01). The CT value on the LA roof wall was significantly lower in obese group than in non-obese group (21±7 vs. 36±12 HU, P<0.01). The CT value on the LA roof wall correlated negatively with both LA EAT volume (r=-0.80, P<0.01) and EAT thickness (r=-0.72, P<0.01). The LA roof wall thickness did not differ between two groups (2.5±0.5 vs. 2.5±0.3 mm, P=0.88). Our data disclosed different LA wall substrates in obese AF patients. Lower CT values adjacent to thickened EAT may reflect fatty infiltration from EAT, which may explain the pathogenesis of AF in obesity.

18f-Fluorocholine Versus 18f-Fluorodeoxyglucose for PET/CT Imaging in Staging, Follow up or Suspected Relapse of Multiple Myeloma

Introduction: Hybrid positron emission tomography/computed tomography (PET/CT) has now become available, as well as whole body, low dose multi-detector row computed tomography (MDCT) or magnetic resonance imaging (MRI). The usefulness of 18F-fluorodeoxyglucose (FDG) PET/CT in evaluating multiple myeloma (MM) has been proven for several years but its sensitivity is imperfect. In a pilot study, we showed that 18F-fluorocholine (FCH) could have some advantages compared to FDG in suspected relapsing or progressive MM, since it is able to pinpoint lesions with a less intense metabolism and/or located in the skull, which are not revealed by FDG. The aim of the present study was to compare the diagnostic performance of PET/CT using FCH and FDG, in various settings of MM: staging, follow-up or suspected relapse.Methods: FDG and FCH PET/CTs were both performed within few days (less than 30 and without specific treatment in the meanwhile) in 77 consecutive patients with MM referred between November 2015 and June 2017. For each patient and each tracer, two blind readers determined the number of foci (intraosseous and extraosseous), measured their intensity of uptake by their SUVmax and by the corresponding target/non-target ratio (T/NT). A consensus reading was made between the two masked readers. Bone spread was divided into three patterns: innumerable foci (more than 10), countable bone foci (less or equal to 10) or diffuse bone marrow infiltration.Results: The 77 patients (average age = 67.3 year old) underwent 95 couples of FDG and FCH PET/CTs, all within 30 days: 17 for staging, 45 for follow-up (some patients had iterative PET/CTs) and 33 for suspected relapse. Among the 45 follow-up PET/CTs, 13 were intended purely to monitor treatment. No foci were found in 41 PET/CTs (6 for staging, 22 for follow-up and 13 for suspected relapse). Uncountable foci were observed in 10 cases with both tracers, but mismatched FDG/FCH foci in 1 case. Concerning countable foci, in 5 staging PET/CTs FDG showed 21 foci vs. 22 FCH foci, in 18 follow-up PET/CTs 32 FDG foci vs. 41 FCH foci, in 14 cases of suspected relapse 26 FDG foci vs. 55 FCH foci (+53%). Median SUVmax and T/NT was overall greater for FCH than for FDG, significantly in case of suspected relapse. There was no significant difference for median SUVmax and T/NT between FDG and FCH PET/CTs performed for staging. Of the 7 cases of diffuse bone marrow infiltration, 2 were better detected with FDG and 5 with FCH. Extramedullary spread was detected in 2 patients, foci of similar intensity being visible with both tracers. In all PET/CTs monitoring treatment for efficacy evaluation, FCH showed as reliable results as did FDG . FCH had better specificity than FDG, without some misleading foci of FDG in cases of inflammation (two cases), brown fat (one case) or post-traumatic fracture (one case). In 3 patients, the management decided on basis of FDG PET/CT was changed in view of FCH PET/CT.Conclusions: These findings suggest that FCH PET/CT could have a role in all settings of MM, in particular in case of suspected relapse or progression, because it would reveal more lesions than FDG and avoid some pitfalls. Further investigations are needed to determine significance of mismatched FDG and FCH foci, and in which patients it is worthwhile to complete the exploration with FCH, or whether using FCH instead of FDG would lead to detrimental decisions in some patients. [Display omitted] DisclosuresGarderet:Amgen: Honoraria; Takeda: Honoraria.

Imaging peculiarities of gubernaculum tracts in molars as accessional teeth on CT.

ObjectivesThe shapes of gubernaculum tracts (GTs) in molars as accessional teeth remain unidentified. To elucidate imaging peculiarities of GTs in molars with aging on multidetector‐row computed tomography (MDCT).Material and methodsThis retrospective study was conducted using CT images, including maxillary and mandibular molars, with no abnormal findings from 239 patients. Shapes of alveolar bone, GTs, and dental sacs of the maxillary and mandibular molars were analyzed multi‐sectionally. Correlations between 2‐ and 3‐dimensional imaging figures of GTs in molars and chronological age or stage of molar formation were analyzed.ResultsSome forms of GTs in maxillary and mandibular third molars were observed. In the early stage, GTs were visualized as bone defect lines on the dentition and grooves on the mesial alveolar crest continuous with the dental sac to mesial tooth bud. GTs of the third molar formed a J‐shape in maxillary teeth and Y‐shape in mandibular teeth in the middle stage, as alveolar bone around the GT developed. In the mature stage, the course of the GT changed to straight and perpendicular. Some GT forms were also identified in first and second molars. Significant correlations were found between GT alterations and chronological age or stage of molar formation. Moreover, tracts continuing from the distal side of mandibular third molars were detected.ConclusionsThis paper describes the peculiarities and process of progression for GTs in molars, and the existence of tracts continuing from the distal side of mandibular third molars, unlikely dentition with deciduous predecessors. These preliminary data should prove beneficial for studies focusing on GTs in molars.

High Pitch Helical CT Reconstruction.

To avoid severe limited-view artifacts in reconstructed CT images, current multi-row detector CT (MDCT) scanners with a single x-ray source-detector assembly need to limit table translation speeds such that the pitch p (viz., normalized table translation distance per gantry rotation) is lower than 1.5. When , it remains an open question whether one can reconstruct clinically useful helical CT images without severe artifacts. In this work, we show that a synergistic use of advanced techniques in conventional helical filtered backprojection, compressed sensing, and more recent deep learning methods can be properly integrated to enable accurate reconstruction up to p=4 without significant artifacts for single source MDCT scans.

Diagnostic and Prognostic Accuracy of Aortic Valve Calcium Scoring in Patients With Moderate-to-Severe Aortic Stenosis.

Background: Assessing the true severity of aortic stenosis (AS) remains a challenge, particularly when echocardiography yields discordant results. Recent European and American guidelines recommend measuring aortic valve calcium (AVC) by multidetector row computed tomography (MDCT) to improve this assessment.Aim: To define, using a standardized MDCT scanning protocol, the optimal AVC load criteria for truly severe AS in patients with concordant echocardiographic findings, to establish the ability of these criteria to predict clinical outcomes, and to investigate their ability to delineate truly severe AS in patients with discordant echocardiographic AS grading.Methods and Results: Two hundred and sixty-six patients with moderate-to-severe AS and normal LVEF prospectively underwent MDCT and Doppler-echocardiography to assess AS severity. In patients with concordant AS grading, ROC analysis identified optimal cut-off values for diagnosing severe AS using different AVC load criteria. In these patients, 4-year event-free survival was better with low AVC load (60–63%) by these criteria than with high AVC load (23–26%, log rank p < 0.001). Patients with discordant AS grading had higher AVC load than those with moderate AS but lower AVC load than those with severe high-gradient AS. Between 36 and 55% of patients with severe LG-AS met AVC load criteria for severe AS. Although AVC load predicted outcome in these patients as well, its prognostic impact was less than in patients with concordant AS grading.Conclusions: Assessment of AVC load accurately identifies truly severe AS and provides powerful prognostic information. Our data further indicate that patients with discordant AS grading consist in a heterogenous group, as evidenced by their large range of AVC load. MDCT allows to differentiate between truly severe and pseudo-severe AS in this population as well, although the prognostic implications thereof are less pronounced than in patients with concordant AS grading.