64-slice Multidetector Computed Tomography Research Articles

DETERMINATION OF ACCURACY OF 3-MILLIMETER THIN AXIAL SECTIONS OF 64-SLICE MULTI-DETECTOR COMPUTED TOMOGRAPHY SCAN IN DIAGNOSIS OF ACUTE APPENDICITIS

Acute appendicitis is a common cause of acute abdominal pain requiring urgent surgical intervention. Timely diagnosis is crucial to prevent complications such as perforation and reduce morbidity and mortality rates. Clinical diagnosis alone can be challenging, leading to false positives and negatives. Multidetector computed tomography (MDCT) has emerged as a valuable tool in diagnosing appendicitis, but its efficacy can be enhanced by optimizing imaging protocols, particularly by utilizing thinner reconstruction sections. We conducted a prospective study involving 150 patients with suspected acute appendicitis. Un-enhanced 64-slice MDCT was performed, and axial images reconstructed from 3mm thin sections were analyzed. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated using SPSS version 19. Our study demonstrated a sensitivity of 97.8% and specificity of 76.9% for diagnosing acute appendicitis using 3mm thin section MDCT. The NPV and PPV were 76.9% and 97.8%, respectively, with an overall accuracy of 96%. Utilizing 3mm thin axial reconstruction in 64-slice MDCT significantly enhances diagnostic accuracy for acute appendicitis. This approach holds promise in reducing negative appendectomies and associated morbidity and mortality rates. Implementation of this imaging protocol can aid in timely diagnosis, optimizing patient care, and reducing unnecessary hospitalizations. 64-slice MDCT with 3mm thin section reconstructed images emerges as a highly accurate technique for diagnosing or excluding appendicitis in patients with equivocal presentations, contributing to improved patient outcomes and healthcare resource utilization.

Exploring the Complex Interplay: Fatty Liver Severity, Epicardial Fat Volume, and Coronary Artery Calcification

Background and Objective: Cardiovascular diseases and nonalcoholic fatty liver disease are the most common non-communicable diseases in most developed countries, and due to lifestyle changes, their incidence is increasing day by day. The present study aimed to assess the correlation of fatty liver with epicardial fat volume and coronary artery calcium score. Materials and Methods: This cross-sectional study was conducted on 136 patients referred to Hamadan Farshchian Cardiovascular Hospital for computed tomography (CT) angiography. They were selected using a consecutive sampling method. Using a 128-slice multidetector CT scanner, the coronary artery calcium score based on the Agatston criteria and epicardial fat volume were measured. A liver ultrasound was performed using a GE voluson E6 and a 3-5 MHz depth probe, and the severity of the fatty liver was determined based on the echogenicity of the liver on the ultrasound. Data analysis was conducted using the SPSS software (version 26). Results: The mean age scores of patients were 52.90±12.10 years. Regarding gender, 50.5% and 49.5% of cases were male and female, respectively. In terms of fatty liver grade, 64 (47.1%), 48 (35.3%), 21 (15.4%), and 3 (2.2%) cases had grades zero, I, II, and III, respectively. The mean calcium score was 30.76±35.40, and epicardial fat volume was 86.84±36.56. The severity of fatty liver demonstrated no significant relationship with calcium score and epicardial fat (P>0.05). Conclusion: As evidenced by the obtained results, the severity of fatty liver had no relationship with the amount of coronary epicardial fat and coronary artery calcium.

Utility of CT Scan in Detecting Bladder Involvement Among Patients With Cervical Carcinoma.

Background Cervical cancer is a widespread health issue in India, particularly affecting women as the second most common cancer. The burden of cervical cancer in the country necessitates accurate staging for treatment optimization. The revised International Federation of Gynecology and Obstetrics (FIGO) staging system is vital for this purpose, emphasizing the extent of parametrial and pelvic sidewall involvement. Cervical cancer's propensity to infiltrate neighboring pelvic organs, including the bladder, necessitates precise staging. In India, traditional methods like cystoscopy have been relied upon, but they have limitations. Recent advancements in medical imaging, notably the increased use of computed tomography (CT) scans, provide a non-invasive alternative for staging and evaluating bladder involvement. This study aimed to evaluate the utility and accuracy of CT scans in assessing bladder involvement. Methods This cross-sectional study examined 127 newly diagnosed cervical carcinoma cases in women over a two-year period from August 2021 to July 2023. Patients underwent CT scans (plain) and cystoscopy, and bladder involvement was determined following the revised FIGO staging. Data collected comprised patient demographics, medical history, clinical symptoms, and FIGO staging. Cystoscopy was performed using an Olympus CYF-5 flexible cystoscope, and CT scans utilized a 64-slice multidetector CT scanner. Radiological reports detailed primary tumor characteristics and proximity to the bladder. Statistical analysis encompassed descriptive statistics, and calculation of sensitivity, specificity, positive predictive value, and negative predictive value for CT scans in comparison to cystoscopy. Statistical significance was considered at p < 0.05. Results In our study, the mean participant age was 45.3 years, with 61.4% falling in the 40-60 years age group. Socioeconomic status (SES) varied, with 37.8% classified as low SES, 48.8% as middle SES, and 13.4% as high SES. Parity data showed that 76.4% had three or more pregnancies. Among presenting symptoms, abnormal vaginal bleeding (65.4%) was the most prevalent, and squamous cell carcinoma (78.7%) was the predominant histological type. The prevalence of bladder involvement was 9.4% by cystoscopy and 30.7% by CT scans. CT scan demonstrated a high sensitivity (100%) but lower specificity (76.52%), with 78.80% overall accuracy. Conclusion A combined approach, using CT scans as a screening tool and cystoscopy as a confirmatory method, could provide the most comprehensive and reliable assessment of bladder involvement in cervical carcinoma patients, ultimately contributing to improved patient care and management.

Association of Severity and Type of Pain with Urolithiasis in Adults: A Computed Tomography Urographic Study

Background: Urolithiasis, a prevalent urological condition, especially in areas with warm and dry climates, poses significant healthcare challenges. In Pakistan, part of the "stone-forming belt," the incidence of urolithiasis is consistent with global prevalence rates. Understanding the demographic and clinical presentation patterns is essential for improving diagnostic and treatment strategies. Objective: The study aimed to determine the prevalence and characteristics of asymptomatic urolithiasis in adult patients and to evaluate the efficacy of multidetector computed tomography (MDCT) in detecting urinary tract stones and associated abnormalities. Methods: This cross-sectional study was conducted over four months at the University of Lahore Teaching Hospital's Radiology Department. A total of 112 adult patients aged between 18 to 70 years with symptoms indicative of urinary tract abnormalities were included using a convenience sampling technique. Siemens 64-slice MDCT was employed for diagnosis. The chi-square test and Fisher's Exact Test were utilized for statistical analysis to assess the association between urolithiasis and clinical symptoms, with p-values less than 0.05 considered significant. Results: Out of 112 patients, the prevalence of asymptomatic stones was 2.8%. Bladder stones were identified in 16 patients (14.3%) with a size range of 3-12 mm (mean 7.5 mm, S/D ratio 2.6). Ureteric stones were found in a subset of patients, with sizes ranging from 6-28 mm (mean 13.8 mm, S/D ratio 4.1). The prevalence of hydronephrosis was 39.9% for the left kidney, 26.1% for the right kidney, and 10.9% for bilateral presentation. Non-stone-related findings requiring treatment were identified in 14% of patients undergoing MDCT for renal colic. Conclusion: The study confirmed the prevalence of urolithiasis within the expected range for a high-risk geographic area. MDCT urography proved to be a valuable diagnostic tool in detecting not only urolithiasis but also other significant renal tract abnormalities. The results indicate a need for improved public health strategies, particularly for the at-risk older adult population.

Improving the impact of different input arteries on cerebral CT perfusion parameters and ischemic penumbra

This study aims to examine the impact of different input arteries on cerebral perfusion parameters and the volume of core infarction, ischemic area, and penumbra automatically measured by software in post-processing 256-slice CT brain perfusion images. Retrospective analysis was conducted on brain perfusion images of 58 patients who underwent 256-slice multidetector CT examination for cerebral infarction. Various input arteries, including bilateral internal carotid artery (ICA), bilateral middle cerebral artery (MCA), anterior cerebral artery (ACA), and basilar artery (BA), were selected for image processing and measurements. The volumes of core infarction, ischemic area, and penumbra were automatically calculated using software. Additionally, manual measurements were per-formed by experienced doctors. Perfusion parameters including cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to peak (TTP) were evaluated. The change of input artery resulted in a significant difference in CBF and MTT in the penumbra and normal brain tissue areas. However, no significant difference was observed in CBV, TTP, and perfusion parameters in the core infarct area. The volumes of core infarction acquired from different input arteries showed no significant difference. Nonetheless, significant differences were found in the volume of the ischemic area and the mismatched area. The selection of different input arteries affects CT cerebral perfusion parameter values and the automatic measurement of the ischemic area and penumbra by software. Thus, when performing post-processing of CT cerebral perfusion images, it is advisable to choose the thicker internal carotid artery on the healthy side as the input artery.

Flat panel CT versus multidetector CT in skull base imaging: are there differences in image quality?

BackgroundPurpose of this study was to compare image quality of the skull base in standard 20s protocol flat panel computed tomography (FPCT) with the new time and dose improved 10s protocol as well as with 128 slice multidetector computed tomography (MDCT).Methods10 whole skull preparations were scanned with either 128 slice MDCT(SOMATOM Definition AS+, Siemens, Erlangen) or FPCT (AXIOM-Artis, Siemens, Erlangen) using 10s or 20s protocol.ResultsFPCT provides significantly better image quality and improved delimitation of clinically relevant structures in the anterior, temporal and posterior skull base compared to 128 slice MDCT. The 20s FPCT protocol yielded best delimitability of evaluated skull base structures. However, the shorter, dose saving 10s FPCT protocol was still significantly superior to 128 slice MDCT regarding delimitability of skull base structures and additionally showed no significant inferiority compared with the 20s FPCT protocol.ConclusionsThe 10s FPCT protocol yields a significantly better image quality at a comparable radiation dose exposure in imaging skull base structures compared to MDCT.Trial registration371/2017BO2.

Computed tomography versus ultrasonography in the evaluation of periumbilical abdominal pain

Background: The objective of this study was to study, assess, and make early diagnosis of periumbilical pain abdomen accurately. Aims and Objectives: To study, assess, and diagnose causes of periumbilical abdominal pain accurately so as to minimize the unnecessary exploratory laparotomy and operations and consequently improved patient care and to compare the role of ultrasonography (USG) and computed tomography (CT) in the evaluation of various causes of periumbilical abdominal pain. Materials and Methods: This prospective study (CTRI/2023/01/048809) was done on 315 patients with periumbilical pain at M.L.B. Medical College Jhansi, Uttar Pradesh on PHILIPS 16 Slice multi-detector CT SCAN machine and GE Vivid T8 ultrasound machine. These patients were blindly and randomly divided by chit system into two groups irrespective of their age and gender. The first group of patients which included 160 patients undergoes ultrasonographic evaluation and the other group of patients which includes 155 patients undergoes contrast-enhanced computed tomographic evaluation. Results: Among 315 patients, the most common cause of periumbilical pain was found to be appendicitis followed by bowel pathologies which include gastrointestinal tuberculosis. Conclusion: USG is the initial modality and modality of choice in female and young (3rd and 4thdecade) patients presenting with periumbilical pain as it is diagnostic in gynecological causes of periumbilical pain and also minimizes unnecessary radiation exposure to female and young patients. Contrast-enhanced CT is the modality of choice in male and old age patients (5th and 6th decade) as it is diagnostic in vascular causes. Overall plain CT has limited role.

Diagnostic Accuracy of Hyperdense Artery Sign in Early Detection of Middle Cerebral Artery Infarction: A Cross-Sectional Validation Study

Background Hyperdense middle cerebral artery sign (HMCAS) on a non-enhanced multidetector computed tomography (MDCT) scan is considered an important radiological marker in detecting acute arterial thrombotic occlusion, and it is one of the earliest signs of ischemic cerebrovascular accident (CVA). This finding has been observed within 90 min of symptom onset. Modern approaches to patients with cerebral infarction emphasize early diagnosis and management. Purpose To determine the diagnostic accuracy of hyperdense artery signs in early detection of middle cerebral artery (MCA) infarction on non-contrast-enhanced MDCT scan using Magnetic Resonance Angiography (MRA) within 24 h as the gold standard for definitive diagnosis. Method A total of 140 patients aged 35–70 years, referred to the radiology department of Aga Khan University Hospital with clinical suspicion of acute cerebral infarction, were included. After clinical suspicion of acute infarction, the patient underwent an initial complete MDCT scan of the brain, which was performed using Aquilion ONE 640 slice MDCT (Toshiba Medical Systems, Japan). Consultant radiologists, with a minimum of 5 years of experience in MDCT brain imaging, interpreted the images. Follow-up examination with MRA within 24 h was performed to confirm the diagnosis of MCA infarction. Results Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of HMCAS in the early detection of MCA infarction on non-contrast-enhanced MDCT scan using MRA as the gold standard for definitive diagnosis was 96.20%, 93.44%, 95.0%, 95.0%, and 95.0%, respectively. Conclusion This study concluded that the diagnostic accuracy of hyperdense artery signs in the early detection of MCA infarction on non-contrast-enhanced MDCT scans is very high.

Vascular Variations and Incidental Pathologies in Potential Living Renal Donors Using 160-Slice Multidetector Computed Tomography Angiography.

The aim of the study is to evaluate the vascular variations and incidental pathologies in potential living renal donors using 160-slice multidetector computed tomography (MDCT) angiography. This is an observational study conducted at the Department of Radiology from January 2017 to May 2022. In this study, we performed retrospective data analysis of 61 CT renal angiograms, totaling 122 kidneys of potential renal donors, using a Toshiba 160 slice MDCT scanner with a four-phase CT image acquisition protocol, performed for pre-transplant workup. All patients had normal renal functions. Of our 61 patients, 34 (55.7%) were male and 27 (44.3%) were female, and their mean age was 31.2 ± 9.4 years. We have found 31 (50.8%) variations in the right renal arteries and 21 (34.4%) in the left renal arteries. Of these patients, 13 had bilateral renal arterial variations. The late confluence of the renal vein was found in 3.3% of males, multiple right renal veins in 7 (11.5%), and left renal veins in 2 (3.3%). By distributing the data according to gender, we noticed more diversity in the renal vessels of male patients. Left renal artery variations were more frequent in males (16, 76.2%) than in females (5, 23.8%), and they were statistically significant (p=0.02). Likewise, variations in the right renal arteries were also more frequently found in males (19, 61.3%) as compared to females (12, 38.7%). Right renal vein variations were more common in males (9, 81.8%) as compared to females (2, 18.2%) (p=0.05). Frequent renal vascular variations and incidental pathologies in potential living donors were found by MDCT examination, and these vascular variations should be analyzed before renal transplant.

Evaluation of epicardial adipose tissue by coronary multi-detector computed tomography: an independent predictor of obstructive coronary artery disease

BackgroundThe aim of this retrospective cross-sectional study was to investigate the relationship between epicardial adipose tissue and coronary artery disease and its severity.MethodsA total of 344 subjects with clinically suspected coronary artery disease underwent 256-slice multi-detector CT coronary angiography and were categorized as follows: no CAD, non-obstructive CAD (luminal narrowing < 50%) and obstructive CAD (luminal narrowing ≥ 50%). Calcium score was quantified using the Agatston method. Mean Epicardial adipose tissue (EAT) and mean pericoronary fat thickness (PCFT) were measured and utilized for data analysis.ResultsThere was a significant association between EAT thickness and PCFT with clinical risk factors of CAD including HTN, DM and obesity (P-value: < 0.001) and dyslipidemia (P-value: 0.003, P-value: 0.008 for EAT and PCFT, respectively). EAT thickness and PCFT were significantly higher in obstructive CAD compared to non-obstructive CAD and no CAD categories (P-value: < 0.001). Also, there is positive strong correlation between EAT thickness, PCFT and Calcium score (P-value: < 0.001). Optimal cut-off point of PCFT for estimating obstructive CAD was > 12.87 mm (sensitivity: 77.06%, specificity: 66.06% and AUC:0.76; 95%CI:0.69–0.81) via receiver operating characteristic curve. On multivariate logistic analysis which included conventional risk factors of CAD, PCFT was an independent predictor of obstructive CAD (Odds ratio:1.55; P-value: < 0.001).ConclusionsEAT thickness and PCFT were significantly increased in coronary artery disease. PCFT is a simple accessible marker for predicting obstructive CAD with acceptable diagnostic performance.

Assessment of Utility of Computed Tomography Pulmonary Angiography in Pulmonary Embolism

Background: Among all the available diagnostic tools, computed tomography (CT) is the preferred diagnostic tool for clinically suspected pulmonary embolism (PE) cases. Further, with the development of multi–detector row CT (MDCT) technology, previous limitations of CT have been overcome effectively. For patients with clinical suspicion of PE, MDCT pulmonary angiography has become the first line of modality for the diagnosis. Aims and Objectives: To evaluate various common observations of CT pulmonary angiography (CTPA) in suspected cases of PE that could accurately determine the choice of management. Materials and Methods: Fifty patients with clinically suspected PE referred to the department of Radiodiagnosis for CTPA from various departments were studied in the cross-sectional study. CT images were obtained with a SIEMENS 64-slice multi-detector CT scanner (somatom definition AS). Images were reconstructed into 3D, axial, coronal, sagittal maximum intensity projection sections, and volume rendering techniques. The axial as well as reformatted coronal and sagittal images were evaluated. Results: The incidence of PE was 52%. The incidence of PE was highest in patients older than 60 years (30.8%) and males (30.3%; p=0.662). The most common symptoms evoking a suspicion of pulmonary embolism were dyspnea (69.2%), followed by chest pain (15.4%), cough (11.5%), and hemoptysis (3.8%). Out of 26 patients who had PE, 61.5% had right ventricular enlargement. DVT (23.1%) was the most common past history. The majority of the patients had thrombus in the right main pulmonary artery (21.1 %), followed by the left main pulmonary artery (19.3 %). Conclusion: In clinically suspected cases of PE, MDCT pulmonary angiography was a useful diagnostic tool. CTPA is the modality of choice for its rapid, minimally invasive, and well-tolerated nature.

Cardiovascular risk factors and pericardial fat volume as predictors of coronary atherosclerosis burden in postmenopausal women: A retrospective, single center study.

Little is known about the clinical relevance of pericardial fat volume (PFV), compared to other conventional cardiovascular risk factors, as predictors of coronary atherosclerosis severity among postmenopausal women. Our main aim was to assess the association of PFV and cardiovascular risk factors with coronary atherosclerosis burden, including occlusive coronary artery disease (CAD) (luminal stenosis >50%), coronary artery calcium score (CAC)>100, and plaque types in postmenopausal women. Patients who had chest pain of angina and referred for 64-slice multi-detector CT (MDCT) angiography examination to exclude occlusive CAD presence were enrolled in this retrospective study. A total of 241 women with absence of menses for more than 2 consecutive years and not taking hormone replacement therapy were enrolled in the present study. Increased PFV(OR[CI] = 1.1 [1-1.3],p = 0.004), age (OR [CI] = 1.1 [1-1.4],p = 0.002), and diabetes mellitus (OR [CI] = 2 [1-4],p = 0.025)were significant predictors of occlusive CAD presence. Increased PFV(OR [CI] = 1.1 [1-1.4],p = 0.017)and increased age (OR [CI] = 1.2 [1.1-1.4],p < 0.001)were better predictors of CAC>100 than other cardiovascular risk factors. Regarding coronary plaque types, increased age (OR [CI] = 1.1 [1.1-1.3],p = 0.001)showed a significant association with coronary calcified plaque presence while increased body mass index(OR [CI] = 1.2 [1-1.4],p = 0.018)showed a significant association with coronary non-calcified plaque presence. Higher PFV values showed an independent association with occlusive CAD and significant coronary calcification. This may imply that increased PFV is likely associated with the development of advanced and severe phenotype of coronary atherosclerosis among postmenopausal women with suspected CAD.

Relationship of cardiovascular risk factors, pericardial fat, and carotid thickness with coronary plaque type in patients with diabetes mellitus.

There is paucity of data on the potential predictors of coronary plaque types among patients with diabetes mellitus(DM). To assess the association of cardiovascular risk factors, pericardial fat volume (PFV) assessed by multi-detector CT(MDCT)angiography, and internal carotid intima media thickness with coronary atherosclerotic plaque types in patients with type 2 DM. Patients with suspected coronary artery disease who underwent 64-slice MDCT angiography were enrolled in this retrospective study. A total of 784 patients were enrolled in this study, 198 of whom had DM and 586 of whom did not. The prevalence of calcified and mixed plaques was significantly higher in the DM group than without DM group, while no significant difference was found in the distribution of non-calcified plaque between groups. There was significant association between smoking [OR(CI) = 4(2-10),P = 0.001] and increased age[OR(CI) = 1.1(1-1.3),P = 0.023] and calcified plaque presence. Regarding mixed and non-calcified plaque, increased PFV[OR(CI) = 1.1(1-1.3),P = 0.001] and positive family history[OR(CI) = 4(2-12),P = 0.049] showed a significant association with coronary mixed plaque presence while no significant association was observed between cardiovascular risk factors, PFV, and internal carotid intima media thickness and non-calcified plaque presence in patients with DM. Increased PFV showed significant and independent association with mixed coronary plaques development, which suggests that PFV may be used as an imaging marker for early detection of increased risk for future coronary events in patients with DM.

Coronary CTA Amidst the COVID-19 Pandemic: A Quicker Examination Protocol with Preserved Image Quality Using a Dedicated Cardiac Scanner.

There has been an ongoing debate on the means to minimize the time patients spend at health care providers during the COVID-19 pandemic. We propose a strategy relying solely on intravenous (i.v.) beta-blocker administration for heart-rate (HR) control prior to coronary CT angiography (CCTA). We aimed to assess a potential difference in CCTA image quality (IQ) after implementation of a modified strategy compared to our standard protocol of oral premedication during the first wave of COVID-19. We analyzed CCTA examinations conducted one year before (n = 1511) and after (n = 1064) implementation of this new regime. Examinations were performed both on our 256-slice multidetector CT (MDCT) and dedicated cardiac CT (DCCT) scanners. We used a four-point Likert scale (excellent/good/moderate/non-diagnostic) for IQ assessment of the coronaries. We detected a significant increase in mean HR during examinations on both CT scanners (MDCT: 62.4 ± 10.0 vs. 65.3 ± 9.7, p < 0.001; DCCT: 61.7 ± 15.2 vs. 65.0 ± 10.7, p < 0.001). The rate of moderate/non-diagnostic IQ significantly increased on the MDCT (192/1005, 19.1% vs. 144/466, 30.9%, p < 0.001), while this ratio did not change significantly on the DCCT (62/506, 12.3% vs. 84/598, 14.0%, p = 0.38). The improved temporal resolution of DCCT allows the stand-alone use of i.v. premedication with preserved IQ; hence, the duration of visits can be shortened.

Role of Multidetector Computed Tomography in the Assessment of Malignant Large-Bowel Lesions

Abstract Background and Objective: Intestinal disease can be examined with computed tomography (CT), which also allows for an assessment of extraintestinal pathology. In addition, CT enhances diagnostic specificity (SP) and offers an exceptional evaluation of the perienteric anomalies that typically accompany bowel disorders. The preoperative grading accuracy was found unappealing, varying between 48% and 77%. The bowel wall thickening among individuals with colorectal cancer is classified as benign or malignant depending on the extent of thickening, symmetrical and asymmetrical thickening, focal, segmental, or diffuse involvement, and related perienteric anomalies. The current study used a cohort of patients with colorectal cancers. The study aimed to find out sensitivity (SN) and SP of multidetector CT (MDCT) in detecting malignant pathologies of the large bowel by comparing the MDCT diagnosis with findings of histopathological examination. Materials and Methods: The study was an observational study, done from December 2019 to December 2021 in the Department of Radiodiagnosis, MES Medical College, Perinthalmanna, Kerala. The patients included were clinically and radiologically indicative of bowel lesions, who were referred with clinical suspicion of large-bowel diseases. The 16-slice Philips ACCESS MDCT scanner was used for MDCT. Oral, rectal, and IV contrast were used after plain CT imaging. Results: The study consisted of 63 patients, of which 53 lesions were found to be malignant on MDCT. However, only 51 patients had cancer verified by histology. Histopathology indicated that the two instances, which the MDCT had identified as malignant, were actually inflammatory. Therefore, for the diagnosis of malignant tumors, MDCT had a SN of 98.10%, SP of 81.80%, a positive predictive value of 96.20%, and a negative predictive value of 90.00% in the present study. On histology, a case that was first identified as benign on MDCT turned out to be malignant. Benign abnormalities on CT showed broad intestinal involvement and modest, symmetric wall thickening. The CT characteristics of malignant tumors included localized intestinal involvement and pronounced asymmetric wall thickening. Conclusion: MDCT has shown to be a trustworthy method for the purpose of evaluating and discriminating benign from malignant colon and rectum tumors. In addition to merely identifying a tumor, MDCT also offers additional information on any perienteric anomalies that may be present around the lesion, the presence of lymph node enlargement, invasion of adjacent viscera, the existence of intestinal obstruction, and metastatic tumors.

Role of Multidetector Computed Tomography in the Detection and Characterisation of Benign and Malignant Non Lymphoid Masses of the Neck and its Concordance with Fine Needle Aspiration Cytology

Introduction: Computed Tomography (CT) enables the evaluation of both osseous and soft tissue details and has become an important imaging modality in the evaluation of patients presenting with a neck mass. The study was conducted to justify the usefulness of Multidetector CT (MDCT) in patients presenting with neck lesions. Aim: To detect benign and malignant non lymphoid lesions of the neck using MDCT imaging features and compare it with Fine Needle Aspiration Cytology (FNAC). Materials and Methods: This cross-sectional study undertaken in a Government Stanley Medical College, Chennai, India, the duration of the study, from June 2021 to May 2022. Contrast Enhanced CT (CECT) was performed with a 16 slice MDCT scanner pre and postcontrast administration. The benign and malignant lesions were evaluated by their enhancement patterns, necrosis, bony and vascular invasion and extension to adjacent neck space. The results were compared with FNAC being considered the gold standard, sensitivity and accuracy of CT was determined. The collected data was analysed with International Business Machines (IBM) Statistical Package for Social Sciences (SPSS) Version 23.0. Results: Of the total 95 patients who were enrolled in to the study, 38 patients were females and 57 patients were males, the mean age of the subjects studied were 45.1±17.4 years, 67 cases were benign lesions and 28 cases were malignant lesions by FNA. The sensitivity and specificity of MDCT was found to be 78.6% and 95.5%, respectively with a Positive Predictive Value (PPV) of 88.0% and Negative Predictive Value (NPV) 0f 91.4%. Conclusion: MDCT is precise in differentiating malignant from benign lesions of the neck and defining the extent of the lesions and involvement of adjacent structures.

Multidetector Computed Tomographic Evaluation of Hydrocephalus

Introduction: Hydrocephalus is characterized by imbalance of cerebrospinal fluid formation and absorption. It is manifested as a dilatation of the ventricular system. Computed tomography (CT) is useful in determining the ventricular size and shape as well as the amount of the cerebral cortex present in the evaluation of suspected hydrocephalus. Aim and Objectives: Detection of hydrocephalus and determining the cause of hydrocephalus. Differentiating communicating from noncommunicating (obstructive) hydrocephalus. to assess the severity of the hydrocephalus and seek for any consequences. Materials and Methods: This prospective study included 50 patients referred to the Acharya Vinoba Bhave Rural Hospital, Sawangi (Meghe), Wardha, for 1 year. Patients clinically diagnosed with hydrocephalus were included in the study. Multidetector CT (MDCT) imaging was performed on Siemens 16 Slice MDCT machine. Multiplanar reformation and three-dimensional reconstruction were done wherever necessary. Results: 20% were diagnosed to have meningitis, 10% had Intraparenchymal haemorrhage and Intraventricular extension, 12% had aqueduct stenosis, and 12% had communicating hydrocephalus. In the study, 40% of them had communicating-type hydrocephalus or extraventricular obstructive hydrocephalus and 60% had obstructive hydrocephalus. On the CT scan, it was observed that at the lateral ventricle, dilatation was observed in four regions. Frontal horn dilatation (98%), body dilatation (98%), and 100% dilatation were seen at the temporal horn and occipital horn. Among 100 patients, 14% had cortical thinning and thus were classified as severe hydrocephalus with a poor prognosis, and 20% had periventricular edema. Conclusion: CT is the best means of obtaining images as it is easily available, fast, reliable, and compatible with standard life support devices.

Diagnostic accuracy of lower-dose cardiac CT in evaluating young infants with non-coronary complex congenital heart disease on a 64-slice multidetector CT scanner.

Redoable precise and non-invasive diagnostic imaging modality with the least radiation dose is essential for infants with congenital heart disease (CHD) . To investigate the accuracy and estimate the radiation dose of our cardiac computed tomography (CCT) protocol. A total of 82 infants with CHD underwent non-ECG-gated CCT without contrast timing scanning techniques and were retrospectively studied. The image quality and radiation dose were estimated. The radiation dose was compared statistically to virtual retrospective ECG-gated and prospective ECG-triggering scanning modes. The diagnostic accuracy was assessed assuming the surgical results as the diagnostic gold standard. Most exams showed a high quality with low radiation doses compared to previous studies. The mean effective dose (ED) was 0.39 ± 1.2, significantly lower than that of the virtual retrospective ECG-gated and prospective ECG-triggering scanning and lower than in previous studies. Our CCT protocol has achieved a diagnostic accuracy of 99.52% with a sensitivity of 94.83% and specificity of 99.91%. Non-ECG-gated CCT without contrast timing techniques can detect the non-coronary cardiovascular defects of CHD in infants with an ultralow radiation dose and a high diagnostic accuracy.

Abstract 14663: The Impact of Continuous Positive Airway Pressure for Sleep Apnea on Left Atrial Dilatation in Patients Receiving Catheter Ablation of Atrial Fibrillation

Background Sleep apnea (SA) and left atrial dilatation (LA) are both risk factors for an arrhythmia recurrence after catheter ablation (CA) of atrial fibrillation (AF). Negative intrathoracic pressure fluctuations during an obstructive apnea episode may cause the left atrium to distend and stretch its wall. However, the impact of continuous positive airway pressure (CPAP) for SA on the reverse LA remodeling has not been elucidated. Methods This study was conducted under a retrospective, single-center, observational design. Data was derived from screening tests for sleep apnea, which were routinely performed in patients scheduled to receive CA of AF in our institution. The severity of the sleep apnea was evaluated by the apnea-hypopnea index (AHI). After excluding patients who were already diagnosed with sleep apnea, we enrolled 1232 consecutive patients who underwent multidetector computed tomography (MDCT) both before and 3-months after the CA of AF. The left atrial dilatation and volume reduction were evaluated by the left atrial minimum volume (LA min V) using 256-slice MDCT. Results The age was 65±11 years, 27.8% were females, and 46.0% had non-paroxysmal AF. The mean AHI was 20.2±15.2 and LA min V 79.1± 37.8ml (r=0.31, p&lt;0.0001) before CA. LA dilatation was defined as an LA min V≥79.1ml. After an adjustment by an advanced age (≥65 years), non-paroxysmal AF, male sex, obesity, hypertension, diabetes, and congestive heart failure, SA (AHI≥5) was a significant predictor of LA dilatation before CA (odds ratio 2.83, 95% confidence interval 1.55-5.16, p=0.0007). After CA, 206 out of 1092 patients (18.9%) with SA started CPAP. SA patients with CPAPs had a greater LA min V reduction rate on the postprocedural CT than those without CPAP (26.2% vs. 20.5%, p=0.013). Conclusion Among the patients scheduled to receive catheter ablation of AF, SA was independently associated with left atrial dilatation. Patients who started CPAP treatment for SA had greater LA reverse remodeling at 3 months after the CA.

Gross anatomy, computed tomography, magnetic resonance imaging and bone mineral densitometry of the ovine metacarpo/metatarsophalangeal joint.

This study was aimed to provide anatomical atlas of the ovine metacarpo/metatarsophalangeal joints using computed tomography (CT) scan and magnetic resonance imaging (MRI), as well as to investigate bone mineral density (BMD) and morphometric features of this joint. The limbs of twenty adult Sanjabi sheep were examined. Imaging was performed using a 16-slice multi-detector CT scanner and a 1.5 Tesla MRI scanner. The obtained images were correlated with corresponding anatomical sections. BMD was measured by Dual Energy X-ray Absorptiometry (DEXA) method. Also morphometric features included distance between metacarpal and metatarsal heads, width of metacarpal and metatarsal head, length, width and the height of the proximal sesamoid bones were measured. In MRI images, compact bones, ligaments and tendons showed less signal intensity (hypointense). The fatty tissue and bone marrow had more signal intensity (hyperintense), but articular cartilage and synovial fluid showed moderate signal intensity. BMD in the left hind limb was significantly higher than other three limbs (p ≤0.05). The length of proximal sesamoid bones in left forelimb was higher than right forelimb (p ≤ 0.05). The thickness of proximal sesamoid bones in left limbs was higher than those in their counterparts (p ≤ 0.05). The width of the medial head in the forelimbs was significantly greater than the hind limbs (p ≤ 0.05). The present results might be useful in managing the clinical techniques on this joint. Larger volume of the proximal sesamoid bones and wider medial head in the forelimbs compared to the hindlimbs impel this speculation that the centre of gravity is closer to the forelimbs.