Computed Tomography Scan Of Abdomen Research Articles

Differential Impact of Subcutaneous and Visceral Fat on Bone Changes after Gastrectomy.

Osteoporosis and fragility fractures are crucial musculoskeletal complications in long-term survivors of gastric cancer. However, the relationship between changes in body composition after gastrectomy and bone loss has not been investigated. Therefore, this study aimed to explore whether computed tomography (CT)-derived body composition parameters are associated with bone loss after gastrectomy in patients with gastric cancer. We retrospectively reviewed medical records and abdomen CT scans of patients who underwent gastrectomy at Yonsei University Severance Hospital between 2009 and 2018. Patients with non-metastatic gastric adenocarcinoma and preoperative and postoperative non-contrast CT scans were analyzed. Section area of skeletal muscle (SMA), visceral fat (VFA), and subcutaneous fat (SFA) were assessed using semi-automatic segmentation software. Changes in trabecular bone attenuation of L1 mid-vertebra level (L1 Hounsfield units [HU]) were measured. Fifty-seven patients (mean age, 65.5±10.6; 70.2% males) were analyzed, and the median duration was 31 months. Fortyseven patients (82.5%) lost weight after gastrectomy. Baseline SMA and VFA did not differ between the bone loss and preserved groups; however, baseline SFA was significantly higher in the bone preserved group than in the bone loss group (P=0.020). In a multivariable linear regression model adjusted for confounding factors, one standard deviation higher VFA at baseline was associated with greater annualized L1 HU loss (%) (P=0.034). However, higher preoperative SFA was associated with protection against bone loss after gastrectomy (P=0.025). Higher preoperative SFA exhibited a protective effect against bone loss after gastrectomy in patients with non-metastatic gastric cancer, whereas VFA exhibited a negative effect.

Effect of arm position on image quality and radiation dose during thorax and abdomen computed tomography scans

IntroductionDuring Computed Tomography (CT) scans of the Thorax-Abdomen-Pelvis (TAP) the patient's arms should be positioned above the head to obtain optimal image quality and expose the patient to the lowest possible radiation dose. This may be impossible with patients with shoulder problems leading to arms being positioned in other ways. This study aimed to investigate differences in objective image quality and estimated effective dose (E), when positioning the arms below shoulder level in CT-TAP. MethodsAn anthropomorphic phantom with cadaver arms was used. Four arm positions were tested: Along the torso (A), on the pelvis (B), on a pillow on the pelvis (C), and one arm on pillow on the pelvis and the other arm on the pelvis (D). A Siemens SOMATOM Definition Flash CT-scanner with CareDose 4D was used. The dose length product was read to estimate E. Image quality was assessed objectively by measuring noise within the region of interest in the liver and urinary bladder. ResultsSignificant differences in E between all arm positions were seen (p = 0.005). The lowest E was obtained in position C, reducing E by 8.42%. Position A provided the best image quality but the highest E. ConclusionThis study showed no unequivocal optimal positioning of arms in CT-TAP. Position A provided the best object image quality, while position C yielded the lowest E. These results may impact the planning of diagnostic CT where positioning of arms may influence optimal image quality and radiation dose. Implication for practiceThis study illustrates tendencies for objective image quality and E when arms are positioned below shoulder level. Further research is needed to assess the clinical relevance with the diagnostic potential.

Feasibility Analysis of Individualized Low Flow Rate Abdominal Contrast-Enhanced Computed Tomography in Chemotherapy Patients: Dual-Source Computed Tomography With Low Tube Voltage.

The aim of the study is to investigate the feasibility of using dual-source computed tomography (CT) combined with low flow rate and low tube voltage for postchemotherapy image assessment in cancer patients. Ninety patients undergoing contrast-enhanced CT scans of the upper abdomen were prospectively enrolled and randomly assigned to groups A, B, and C (n = 30 each). In group A, patients underwent scans at 120 kVp with 448 mgI/kg. Patients in group B underwent scans at 100 kVp with 336 mgI/kg. Patient in group C underwent scans at 70 kVp with of 224 mgI/kg. Quantitative measurements including the CT number, standard deviation of CT number, signal-to-noise ratio, contrast-to-noise ratio, subjective reader scores, and the volume and flow rate of contrast agent were evaluated for each group. There was no statistically significant difference in the subjective image scores within the three groups except for the kidney (all P > 0.05). Group C showed significantly higher CT values, lower noise levels, and higher signal-to-noise ratio and contrast-to-noise ratio values in the majority of the regions of interest compared to the other groups (P < 0.05). In group C, the contrast agent dose was decreased by 46% compared to group A (79.48 ± 12.24 vs 42.7 ± 8.6, P < 0.01), and the contrast agent injection rate was reduced by 22% (2.7 ± 0.41 vs 2.1 ± 0.4, P < 0.01). The use of 70 kVp tube voltage combined with low iodine flow rates prove to be a more effective approach in solving the challenge of compromised blood vessels in postchemotherapy tumor patients, without reducing image quality and diagnostic confidence.

Comparative analysis and assessment of radiological investigation reports for abdomen and pelvic computed tomography scans

Background: Medical imaging modalities have significantly improved the accuracy and timeliness of diagnoses over the years; they also present a risk of diagnostic errors due to various factors. One of the primary issues is the variation in findings between preliminary and final reports, specifically for current imaging technologies such as magnetic resonance imaging, and computed tomography (CT) among others. Although several studies have investigated variations between preliminary and final reports in different contexts, research specific to the radiology department is limited. Through this study protocol, we aim not only to help provide a comprehensive evaluation of the variation in findings between preliminary and final diagnostic reports in radiology but also aid in improving the accuracy and quality of patient care and contribute to developing effective strategies to minimize diagnostic errors. Methods: A total of 128 male and female patients presenting to the radiology diagnosis department for abdomen and pelvic CT scans would be considered for the study. The radiological investigation reports for the scans would be interpreted by junior residents and radiologists. The reports will be manually compared to check for similarities, new findings, and exclusions. The degree and frequency of variability will be statistically assessed and reported in tabulations and graphs under the patient's age and gender. Discussion: This study seeks to investigate the differences in interpretations between resident and radiologist reports, consistent with previous research. The results of this study will provide insights into the variations in interpretations, highlighting the importance of continuous training. Examining the findings of a report as a whole can also deliver valuable knowledge into the potential impact on patient care. This can lead to enhancements in radiology reports and overall patient management. The implications involve improving the education of residents, optimising clinical decision-making processes, and promoting positive patient outcomes.

Influence of tube and patient positioning in thoracoabdominal CT examinations on radiation exposure–towards a better patient positioning

Although iso-centric patient positioning is enormously important in computed tomography (CT), it is complicated in thoracoabdominal imaging by the varying dimensions of the body. Patient positioning can affect the appearance of the patient on the localiser. Positioned too close to the x-ray tube, a patient appears considerably more voluminous. The goal of this study is to assess the difference in radiation exposure of combined chest and abdomen CT scans between scans with prior 0°- and 180°-localisers in conjunction with patient positioning. In this IRB-approved retrospective study, patients who had two routine thoracoabdominal CT scans on the same CT scanner, one with a prior 0°- and one with a prior 180°-localiser, were included. To evaluate the radiation exposure of the thoracoabdominal CT examination regarding the tube position during the localiser, volumetric computed tomography dose index (CTDIvol), size-specific dose estimate (SSDE), patient diameter and positioning within the iso-centre for three positions (heart, abdomen, femur level) were compared with regard to the tube position during the prior localiser. CT examinations of 114 patients were included. Despite similar patient weight and diameter between the two examinations, SSDE and CTDIvol was significantly larger (up to 73%) with 180°-localisers. Patient offset from the iso-centre ranged between −9 mm at the centre slice (abdomen level) to −43 mm at the most caudal slice at the pelvis (femur level), causing a significant magnification (p < 0.001) on 180°-localisers with a subsequent increase of the apparent attenuation. The results of this study emphasise the use of 0°-localisers in thoracoabdominal CTs, since 180°-localisers caused patient magnification with subsequent increase in radiation exposure. The advantage of 180°-localisers, namely reducing the dose in thyroid and breast, is eliminated if the dose of the CT scan increases significantly in the abdomen and pelvis.

Radiation Dose Measurement during CT Abdomen Examination of Adult Patients: A Cross-Sectional Study

Background: Computed tomography (CT) has become a routine imaging modality for many clinical applications due to its wide availability, minimally invasiveness, short scan time, excellent anatomical resolution, and high diagnostic value. The radiation dose to patients from CT examinations is the highest contributor to diagnostic medical exposure, which is a growing public concern. The aim of this study was to measure radiation doses for abdominal CT examinations in adult patients and compared them to international standard dose values. Methods: A cross-sectional study was conducted on 92 adult patients with abdomen CT scans using a 16-slice computed tomography scanner at the department of Radiodiagnosis &amp; Medical Imaging, UCMS-TH, Bhairahawa, Nepal from August 2018 to January 2019. The radiation doses were measured by convenient techniques: volumetric computed tomography dose index (CTDIvol), dose length product (DLP) &amp; effective dose (ED) and data were analyzed using SPSS version 20. Results: The mean BMI of the study participants was 23.92±4.29 kg/m2. The mean values of contrast-enhanced scan CTDIvol, DLP, and an ED in our study were 7.31 mGy, 421.46 mGy.cm and 6.31 mSv respectively which is very low as compared to European Guidelines (EG) &amp; International Atomic Energy Agency (IAEA). There was a statistically significant association between patient BMI with CTDIvol, DLP and ED during non-contrast, contrast-enhanced and delayed scans. Conclusion: The CTDIvol, DLP, and ED were lower than the European guidelines and IAEA standards. Toward preventing health effects from ionizing radiation, our study follows public concerns and minimizes radiation doses.

Adult sigmoid intussusception as a rare presentation of advanced adenocarcinoma: a case report

Adult bowel intussusception is a rare clinical entity resulting in 1-5% of intestinal obstructions. It occurs more often in the small intestine and it’s secondary to a pathologic condition in 90% of cases. Its clinical picture can be unspecific, and the diagnosis is often made intraoperatively. We describe an uncommon clinical presentation of this rare clinical entity. A 69-year-old female presented in our emergency room with severe abdominal pain and rectorrhagia. The abdomen computed tomography scan revealed a colonic intussusception and a mass suggestive of a malignancy, as confirmed by rectosigmoidoscopy. The patient underwent the Hartmann procedure. A histopathological examination revealed an advanced colorectal adenocarcinoma as the lead point of the intussusception. Adult sigmoid intussusception is a rare cause of bowel obstruction, and it is often cancer-related. Symptoms can be nonspecific, and diagnosis is best made by CT imaging and endoscopic investigations which allow for planning surgery.

#4767 ACUTE CORTICAL NECROSIS IN PREGNANCY IS STILL AN IMPORTANT CAUSE FOR END-STAGE RENAL DISEASE IN DEVELOPING COUNTRIES

Abstract Background and Aims Renal cortical necrosis (RCN) is a serious complication of acute kidney injury (AKI) and pregnancy is a clinical state closely associated with it with poor renal outcomes. The incidence is much higher in obstetrical AKI compared to other causes of RCN. Despite better medical care facilities available, this continues to be an important cause of morbidity and mortality in developing countries. Method This is a retrospective analysis among all pregnant females presenting with AKI from January 2000 to December 2020 at a tertiary care center in the northern part of India. We looked for the incidence of obstetrical-related RCN in our renal biopsies performed in the last 20 years and to evaluate precipitating factors responsible for RCN. Results RCN constituted 8.1 % of pregnancy-related AKI cases in our institution. The overall incidence has been declining which was 9.09% from 2000 to 2008 to 8.7 % from 2009 to 2014 and 8.1% from 2014-2020. The patient's median age was 28.4 ± 4.6 years. The average time to presentation from the day of delivery was 7.8 ±3.0 days. The mortality was observed in 10.4 % of them with sepsis and multiorgan dysfunction present in all of them. The most common etiology for RCN was found to be septic abortion and puerperal sepsis accounting for - 16.2 % each. Postpartum hemorrhage was a cause in 9.67 % of patients. The most important cause of RCN was postpartum thrombotic microangiopathy which was observed in 49.5% of patients. Kidney biopsy was helpful in diagnosis in 36 patients while computed tomography scan abdomen alone helped in diagnosis in five patients. Patchy cortical necrosis in histology was seen in 36.7% of patients and morbidity in terms of prolonged hospitalization was seen in 23.4 % while dialysis dependency in 63.4% of the study population Conclusion Strategies need to be implemented in reducing the preventable causes for RCN which is not only catastrophic in terms of renal outcomes but also for social and psychological perspectives as well.

Novel radiological technique to recognize acute liver failure caused by yellow phosphorous containing rodenticides.

Yellow phosphorous rodenticide (YPR) poisoning is the commonest cause for acute liver failure (ALF) in southern and western India. Due to medicolegal issues, history of YPR ingestion may not be available. As early recognition of YPR poisoning is important and there are no specific biochemical assays, other early predictors to identify this entity is necessary. We evaluated the diagnostic role of plain computed tomography (CT) in identifying YPR-induced ALF. All patients admitted to the liver unit with a diagnosis of ALF underwent a plain CT scan abdomen. Demographic details, clinical history, laboratory parameters, liver attenuation index (LAI) calculated on CT scan, treatment details, need for liver transplantation and clinical outcome were analyzed. Parameters for YPR-induced ALF (ALF-YPR) and other causes (ALF-OTH) were compared. Ability of LAI to distinguish ALF-YPR and ALF-OTH was analyzed using receiver operating characteristic (ROC) curve analysis. Twenty-four patients (15 female [62.5%]) were included in the study. Thirteen patients (54%) had YPR poisoning, while the rest formed the ALF-OTH group (11,46%). ALF-YPR patients had higher transaminase levels, lower peak serum bilirubin levels. ALF-YPR livers had significantly lower LAI as compared to ALF-OTH (- 30 vs. - 8, p = 0.001). On ROC curve analysis, an LAI greater than - 18 ruled out YPR as the cause for ALF with 91% sensitivity and 85% specificity. On regression analysis, LAI was the only independent factor predicting ALF-YPR (odds ratio - 0.86, [0.76, 0.96] p = 0.008). Our data shows that LAI on plain abdominal CT scan can be used to quickly recognize ALF-YPR in unclear cases so that necessary treatment protocol can be activated, or patient transfer arranged. Our analysis shows that an LAI greater than - 18 can reliably rule out YPR ingestion as the cause for ALF.

Whole-Body Composition Features by Computed Tomography in Ovarian Cancer: Pilot Data on Survival Correlations.

The primary objective of this study was to assess the associations of computed tomography (CT)-based whole-body composition values with overall survival (OS) and progression-free survival (PFS) in epithelial ovarian cancer (EOC) patients. The secondary objective was the association of body composition with chemotherapy-related toxicity. Thirty-four patients (median age 64.9 years; interquartile range 55.4-75.4) with EOC and thorax and abdomen CT scans were included. Clinical data recorded: age; weight; height; stage; chemotherapy-related toxicity; and date of last contact, progression and death. Automatic extraction of body composition values was performed by dedicated software. Sarcopenia was defined according to predefined cutoffs. Statistical analysis included univariate tests to investigate associations of sarcopenia and body composition with chemotoxicity. Association of body composition parameters and OS/PFS was evaluated by log-rank test and Cox proportional hazard model. Multivariate models were adjusted for FIGO stage and/or age at diagnosis. We found significant associations of skeletal muscle volume with OS (p = 0.04) and PFS (p = 0.04); intramuscular fat volume with PFS (p = 0.03); and visceral adipose tissue, epicardial and paracardial fat with PFS (p = 0.04, 0.01 and 0.02, respectively). We found no significant associations between body composition parameters and chemotherapy-related toxicity. In this exploratory study, we found significant associations of whole-body composition parameters with OS and PFS. These results open a window to the possibility to perform body composition profiling without approximate estimations.

Life-threatening Neutropenia After a Short Course of Dual Antiplatelet Therapy for Minor Stroke (P7-5.017)

<h3>Objective:</h3> We present a case of unexpected severe neutropenia in a patient prescribed a 21-day course of double antiplatelet therapy (aspirin and clopidogrel) for ischemic stroke. <h3>Background:</h3> Antiplatelet agents are the cornerstone of atherosclerotic stroke prevention. In recent years, trials such as CHANCE and POINT have popularized the use of a short (3–4 week) course of dual antiplatelet therapy (aspirin plus a P2Y12 inhibitor) after minor stroke or high-risk transient ischemic attack. While some P2Y12 inhibitors such as ticlopidine have been associated with neutropenia, this side effect is exceedingly rare with clopidogrel and has primarily been reported with prolonged use after coronary stenting. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> An 88-year-old woman presented with acute onset of left face, arm, and leg numbness. National Institutes of Health Stroke Scale was 1 for mild sensory loss. Non-contrast computed tomography (CT) of head showed no evidence of hemorrhage or acute ischemia. Brain magnetic resonance imaging revealed a small area of diffusion positivity in the right thalamus consistent with acute ischemic stroke. She was already taking aspirin 81mg daily; clopidogrel 75mg daily was added for a 21-day course. WBC count during admission had ranged from 4.11–6.27 K/uL. On post-stroke day 23, she presented with three days of malaise, abdominal pain, and fever to 102 °F. WBC and absolute neutrophil count were now markedly low (0.67, &lt;0.01 K/uL, respectively). CT scan of abdomen revealed enterocolitis and early appendicitis. She was diagnosed with febrile neutropenia and treated with broad-spectrum antibiotics and filgrastim. As there was no evidence of hematologic malignancy, it was concluded that her neutropenia was drug-induced secondary to clopidogrel. She gradually recovered and cell counts had normalized at follow-up. <h3>Conclusions:</h3> While rare, severe neutropenia can occur with even brief use of clopidogrel. With the widespread adoption of short course dual antiplatelet therapy after stroke, neurologists should be aware of this association. <b>Disclosure:</b> Dr. Culbertson has nothing to disclose. Dr. Blaszkowsky has nothing to disclose.

Quality Assessment of Computed Tomography Images using a Channelized Hoteling Observer: Optimization of Protocols in Clinical Practice.

This study investigated the feasibility of channelized hoteling observer (CHO) model in computed tomography (CT) protocol optimization regarding the image quality and patient exposure. While the utility of using model observers such as to optimize the clinical protocol is evident, the pitfalls associated with the use of this method in practice require investigation. This study was performed using variable tube current and adaptive statistical iterative reconstruction (ASIR) level (ASIR 10% to ASIR 100%). Various criteria including noise, high-contrast spatial resolution, CHOs model were used to compare image quality at different captured levels. For the implementation of CHO, we first tuned the model in a restricted dataset and then it to the evaluation of a large dataset of images obtained with different reconstruction ASIR and filtered back projection (FBP) levels. The results were promising in terms of CHO use for the stated purposes. Comparisons of the noise of reconstructed images with 30% ASIR and higher levels of noise in rebuilding images using the FBP approach showed a significant difference (P < 0.05). The spatial resolution obtained using various ASIR levels and tube currents were 0.8 pairs of lines per millimeter, which did not differ significantly from the FBP method (P > 0.05). Based on the results, using 80% ASIR can reduce the radiation dose on lungs, abdomen, and pelvis CT scans while maintaining image quality. Furthermore using ASIR 60% only for the reconstruction of lungs, abdomen, and pelvis images at standard radiation dose leads to optimal image quality.

Diagnostic Reference Range (DRR) in Computed Tomography (CT) Imaging Based on Clinical Indications Related to Thorax, Abdomen and Pelvic Regions

The concept of diagnostic reference range (DRR) is introduced to address the balance between a patient’s risk (radiation dose) and benefit (image quality necessary for an accurate diagnosis). R provides a minimum estimated dose that covers 25–75% range of dose distribution. The International Commission on Radiological Protection, ICRP (2017) recommended the 75th percentile as the upper d 25th percentile as the lower limit of DRR [1]. Dose below the lower range should compromise accurate interpretation of the image and dose above the upper range may be in excess and need to be reviewed. Meanwhile, Diagnostic Reference Levels (DRLs) are set at the 75th percentile of dose distribution and recommended by ICRP as a guidance to identify any unusual computed tomography (CT) procedures that consistently exceed the established DRLs.&#x0D; The aim of this study was to establish the local DRR for CT scanning based on clinical indications associated to thorax, abdomen, and pelvic regions in adult patients at Department of Radiology, Hospital Universiti Sains Malaysia (HUSM), Kelantan. This study involved a retrospective survey on data of adult patients underwent CT scanning based on 5 most common clinical indications related to thorax, abdomen, and pelvic regions at two departments, Radiology and Trauma Department, HUSM. This study obtained human ethical approval from the university ethical committee (Protocol code: USM/JEPeM/22010025). The CT dose metrics (dose length product, DLP and total DLP) and associated technical factors were collected.&#x0D; Results showed that the five most common clinical indications were cancer staging, coronary artery disease, pulmonary embolism, stones (CTU protocol) and stones (KUB protocol). The DLP values were varied based on their clinical indications and CT scanner types. Figure 1 shows boxplots representing the DRRs of DLP based on five most common clinical indications associated to CT scans of thorax, abdomen, and pelvic regions for Toshiba and Siemens CT scanners. The highest total DLP values was 4722 mGy.cm observed from CT scanning of cancer staging using Siemens scanner. While the lowest DLP value is 40 mGy.cm for stones scanning using the KUB protocol also using Siemens scanner. The main factor that contributes to higher DLP is the longer scanning length.&#x0D; This study demonstrates that the dose descriptor values, DLP and total DLP were varied for similar anatomical region based on different image quality requirement for each clinical indication. Thus, utilisation of both DRR and DRL are crucial to minimise the unnecessary dose to patient and ensure the optimum image quality is produced by each CT scanning.

ODP645 A Rare Case of Extrapulmonary Sarcoidosis with Hypercalcemia as the Initial Presentation: A Diagnostic Conundrum

Abstract Introduction Sarcoidosis is a multi-system chronic granulomatous disease of unknown etiology with a wide array of manifestations. It most commonly affects the lungs. About 30% of the patients present with extra pulmonary sarcoidosis along with lung involvement and approximately 8% present with disease at extrapulmonary site without lung involvement. Here we present a case of asymptomatic extrapulmonary sarcoidosis that presented with hypercalcemia, later confirmed with an axillary node biopsy showing non-caseating granuloma. Case Presentation A 56-year-old male with a past medical history of renal insufficiency presented with an elevated Calcium (Ca) of 11mg/dL, asymptomatic otherwise. Further lab testing revealed a suppressed Parathyroid hormone (PTH) level of 2 pg/ml, Parathyroid hormone related protein (PTHrP) of 14pmol/L, normal 25-Hydroxy Vitamin D (27ng/ml), markedly elevated calcitriol (106 pg/ml) and 24-hour urinary Calcium (961mg/day). Patient also had renal insufficiency with a creatinine of 1.58mg/dL and glomerular filtration rate of 49ml/min/1.73m2. Angiotensin-converting enzyme (ACE) was also found to b elevated at 125units/L. Computed Tomography (CT)) chest showed scattered pulmonary nodules measuring as large as 7.9 mm, CT scan of abdomen revealed splenomegaly and bilateral non-obstructing renal calculi. A subsequent NM bone scan and X-ray bone survey were unremarkable. Patient's calcium levels progressively increased to a maximum of 13.3. A flow cytometry showed no immunophenotypic evidence of a lymphoproliferative disorder. Due to concern for malignancy, a PET scan was done which revealed small scattered hypermetabolic lymph nodes in bilateral external iliac chain and upper retroperitoneum. A solitary hypermetabolic 10mm right axillary lymph node was seen which was then biopsied. Biopsy report showed epitheloid non-necrotizing granuloma and fibrosis, thus confirming diagnosis of sarcoidosis. Patient was started on prednisone 10mg daily empirically before the biopsy results and repeat calcium in 2 months came back at 9.6mg/dl. He was then switched to a maintenance dose of 5 mg. Case Discussion Hypercalcemia is a common clinical laboratory abnormality with 90% of cases attributed to PTH-dependent hyperparathyroidism and malignancy. Although rare, chronic granulomatous diseases can cause a PTH-independent hypercalcemia through enhanced conversion of 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D. Sarcoidosis makes up only 1% of cases of hypercalcemia, making it very challenging to diagnose it as an etiology of hypercalcemia. Furthermore, hypercalcemia is rarely the initial presentation as it happened in our case. All cases of hypercalcemia must be thoroughly evaluated with PTH, 1,25-hydroxyvitamin D, and PTHrP to rule out common etiologies. Corticosteroids are the main stay of treatment of hypercalcemia in sarcoidosis. This case aims to shed light on sarcoidosis as an etiology of hypercalcemia, even though rare, for prompt diagnosis and management. Presentation: No date and time listed

Trainable joint bilateral filters for enhanced prediction stability in low-dose CT

Low-dose computed tomography (CT) denoising algorithms aim to enable reduced patient dose in routine CT acquisitions while maintaining high image quality. Recently, deep learning (DL)-based methods were introduced, outperforming conventional denoising algorithms on this task due to their high model capacity. However, for the transition of DL-based denoising to clinical practice, these data-driven approaches must generalize robustly beyond the seen training data. We, therefore, propose a hybrid denoising approach consisting of a set of trainable joint bilateral filters (JBFs) combined with a convolutional DL-based denoising network to predict the guidance image. Our proposed denoising pipeline combines the high model capacity enabled by DL-based feature extraction with the reliability of the conventional JBF. The pipeline’s ability to generalize is demonstrated by training on abdomen CT scans without metal implants and testing on abdomen scans with metal implants as well as on head CT data. When embedding RED-CNN/QAE, two well-established DL-based denoisers in our pipeline, the denoising performance is improved by 10%/82% (RMSE) and 3%/81% (PSNR) in regions containing metal and by 6%/78% (RMSE) and 2%/4% (PSNR) on head CT data, compared to the respective vanilla model. Concluding, the proposed trainable JBFs limit the error bound of deep neural networks to facilitate the applicability of DL-based denoisers in low-dose CT pipelines.

“All-in-one” window/level whole-body computed tomography scan – A faster way to evaluate trauma cases

PurposeTo investigate the accuracy and total assessment time (TAT) of the “All-in-one” (AIO)-window/level setting for whole-body computed tomography (CT) image compared to multiple tissue-specific window/level settings conventionally used for detection of traumatic injuries. MethodContrast-enhanced chest, abdomen, and pelvic CT scans of 50 patients who presented to our emergency department (ED) for major trauma were retrospectively selected. In a simulation of a “wet read” performed at the CT scanner console, 6 readers with different levels of experience had up to 3 min to describe any traumatic finding identified on the CTs. The readers reviewed each patient in two different sessions separated by a washout period to suppress any recall bias from one session to the next. Each scan was reviewed once using the AIO-window/level setting and another time using the conventional bone, lung, and soft tissue window/level display settings, in a randomized order. The CT reports were used as reference standard. ResultsOverall, there was no statistically significant difference in the assessment accuracy of the review based on the AIO or the conventional window/level settings (0.89 ± 0.09 vs 0.90 ± 0.08). Using the AIO-window/level settings, TAT was 14.3 s faster when compared with the conventional window/level settings (2.33 ± 0.63 vs 2.57 ± 0.51 min; p < 0.001). ConclusionsIn a time-delimited image review, similar diagnostic accuracy was reached faster using the AIO vs the conventional window/level settings. When providing a “wet read” at the CT console, the ability to identify traumatic injury using a single AIO-window/level may help expedite patient management.

S1968 Pregnancy With a Twist: A Case of Sigmoid Volvulus in the Third Trimester

Introduction: Sigmoid volvulus is a rare cause of bowel obstruction in the general population and particularly in pregnancy. Here, we present a case of a young woman in her third trimester presenting with acute sigmoid volvulus. Case Description/Methods: A 27-year-old woman with no prior medical history who was 31 weeks pregnant presented with 4 days of progressive abdominal pain and distension with associated obstipation, nausea, vomiting and decreased oral intake. Her surgical history was pertinent for prior cesarean section and right laparoscopic salpingectomy. Her vital signs are normal. Her abdomen is distended and tender to light palpation with guarding and rebound tenderness. CBC and CMP are within normal limits. A computed tomography (CT) scan of the abdomen and pelvis showed large bowel distension up to 10.5 cm with air fluid levels and twisting of the mesentery at the sigmoid colon. Based on these findings, she was diagnosed with sigmoid volvulus. The patient was emergently taken to the operating room for endoscopic sigmoid volvulus reduction. A therapeutic colonoscopy revealed a sigmoid volvulus with health appearing mucosa which was successfully traversed and detorsion was performed. A nasogastric tube was placed in the rectum with the proximal tip near the hepatic flexure for decompression.The patient’s abdominal pain improved significantly after colonic decompression. Three days later, she underwent definitive open sigmoidectomy with primary anastomosis. Three days later, the patient had vaginal bleeding along with contractions and had breech vaginal delivery of a male infant ( Figure). Discussion: Sigmoid volvulus in pregnancy is rare but should be included within the differential diagnosis for abdominal pain as a delay in diagnosis or late presentation can result in significant morbidity and mortality for mother and fetus. Delays in diagnosis are associated with high rates of morbidity and mortality for the mother and fetus. Maternal complications include sepsis, peritonitis, and bowel perforation. Fetal complications include pre-term delivery, intrauterine death, and neonatal sepsis. Endoscopic decompression is successful in 75-95% of cases. Elective surgery is recommended after endoscopic detorsion. Finally, it is important to have a multi-disciplinary approach with colorectal surgeons and obstetricians in the management of sigmoid volvulus in pregnancy.Figure 1.: Sagittal view of abdomen and pelvis CT Scan.

Profile and Outcome of Children with Opsoclonus Myoclonus Ataxia: A Tertiary Care Hospital Experience from India

AbstractOpsoclonus myoclonus ataxia syndrome (OMAS) is a rare but treatable, often paraneoplastic neuroimmunologic condition. This is a retrospective chart review of 8 patients diagnosed in the past 11 years at a tertiary care hospital. The mean age of children with OMAS was 21.2 ± 8 months. There was a female preponderance (62.5%). Median symptom duration was 24.5 days (interquartile range [IQR] 12.7; 97.5). All patients had ataxia and irritability; 6 had opsoclonus.An underlying neurogenic tumor was identified in 87.5% (⅞) of the patients by computed tomography (CT)/magnetic resonance imaging. Neuroblastoma was detected in ⅘ with normal 24-hour urinary vanillylmandelic acid and 2 had negative metaiodobenzylguanidine scan.All patients received adrenocorticotropic hormone/steroids for a median of 9.5 months (IQR 5.3; 13.5) with clonazepam. Five received intravenous immunoglobulin (IVIG), including repeated cycles in ⅘. Two received rituximab. One child with relapsing-remitting course received pulse dexamethasone and cyclophosphamide, resulting in improvement. Clonazepam restored ambulation in one with delayed diagnosis and failure of response to steroids. Six patients underwent tumor resection and four needed chemotherapies.Median follow-up was 15 months (IQR 10.7; 23.2). Mean OMAS-severity scale reduced from 10 to 1.4 in the IVIG group and 10.6 to 5.3 in those who did not receive IVIG. Cognitive delay and behavioral issues were seen in 100% treated with steroids only; 50 and 25%, respectively, treated with multimodal immunotherapy. Five had relapses, one with tumor recurrence.Thorax and abdomen CT scan was found to be a sensitive tool for tumor detection. Better motor and cognitive behavioral outcome were noted in patients who received adjunctive IVIG.Future studies on optimum investigation and treatment protocol in various resource settings are needed.

Clinical Profile and Management of Chronic Pancreatitis in Tertiary Care Centre

Background Constant inflammation and irreversible pancreatic tissue destruction are hallmarks of the disease of chronic pancreatitis (CP), which results in the decrease of both exocrine and endocrine function over time. It is a multifactorial disease, with a wide range of symptoms and geographic variation. Aim Aim of this study is to study clinical profile and management of CP with respect to demography, clinical findings, lab parameters, imaging investigations and management modalities. Methods A cross-sectional observational study was conducted which included the patients admitted to the tertiary care center presenting with the clinical diagnosis of CP. The study was conducted over a period of 2-years from November 2019 to October 2021. A total sample size of 71 patients was included. Results In the study, it was observed that the majority of patients were in the age group of 51-60-years (47.89%) followed by 41-50-years (21.12%) mean age ranges from 56.54±12.63-years. The majority of patients were male (76.06%) and females were 23.94%. The distribution of patients according to aetiology showed that the majority of patients had aetiology of alcoholism (43.66%) followed by idiopathic (29.57%) Gall/Biliary stones (21.12%) and post-operative (5.63%). Majority of patients presented with pain in the abdomen (85.92%). The distribution of patients according to ultrasound sonography test (USG) findings showed that majority of patients shows pancreatic calcification (54.93%) followed by pancreatic pseudocyst (32.39%) and gall stones (19.72%). The distribution of patients according to computed tomography (CT) findings showed that majority of patients shows pancreatic calcification (70.42%). In the present study, it was observed that majority of patients were managed conservatively (43.66%) followed by cystogastrostomy (18.31%) and cystojejunostomy (8.45%). Endoscopic retrograde cholangiopancreatography (ERCP) was done among 14 (19.72%) patients. Lateral pancreaticojejunostomy was done in 6 (8.45%) patients and pancreaticoduodenectomy (Classical Whipple’s) was done in 4 patients (5.63%). The distribution of patients according to pain relief by various management showed that majority of getting relief from pain by surgery (69.23%) followed by ERCP (35.71%) and the least by conservative/analgesics (6.45%). Conclusion Chronic pancreatitis is progressive inflammatory disease. Alcoholic pancreatitis being most common etiology. Pain is most common presenting symptom. CT scan abdomen most useful in confirming diagnosis in our set up. Pseudocyst being common complication seen. Surgery gives relief of pain in most of the cases. The key to a better outcome is making the right decisions in terms of diagnosis, patient selection for surgery, and surgical type.

A Review on Diagnostic Reference Levels for Adult Patients Undergoing Chest (Coronary Angiography) Computed Tomography Scan in North-East India

In the radiological department, the computed tomography (CT) scan process has become a greater radiation dosage that contributes to all medical X-ray treatments. Many studies throughout the world have found that CT accounts for just 5% of all operations conducted yet accounts for 34% of yearly radiation exposures in all medical X-ray treatments. Similarly, other studies have found that CT accounts for 17% of all operations conducted worldwide but accounts for 49% of total yearly doses in all medical X-ray treatments. Because diagnostic reference levels (DRLs) are one of the ways of optimizing a dose in a CT procedure, the goal of this review is to provide a DRLs for adults who undergo chest and abdomen CT scan examinations in northern India, based on research for this region and comparing with international values to see if better optimization protocol is being practiced. DRLs for the chest are 18.35mGy for CT dose index volume (CTDIvol) and 765 mGy.cm for dose length product (DLP), according to this review, while DRLs for the abdomen are 18.25 mGy and 1870.75 mGy.cm for CTDI (vol) and DLP, respectively. As a result, all of the DRLs examined had greater values than the international values compared, with the exception of CTDI (vol) of International Commission on Radiological Protection 2007 publications. CT technology is in desperate need of an update. In the northern region, optimizing methods, including exposure and technical parameter selection, should reduce dose fluctuations.