Abdominal Tomography Research Articles

6538 Find me if you can! A Case of a "Well Placed Solitary Insulinoma" in "The Center" of an SACST

Abstract Disclosure: R. Kennedy: None. D.A. D'Alessio: None. A.V. Vella: None. Introduction: Selective arterial calcium stimulation testing (SACST) can be utilized in patients to localize solitary insulinomas when imaging is non diagnostic. While a heterogenous stimulation pattern suggests NIPHS, or multiple insulinomas this case uniquely demonstrates such a pattern with a solitary insulinoma. Clinical Case: The patient is a 48 year old female who presented to the emergency department (ED) for bizarre behavior which resolved with a sweetened drink. Serum glucose was 62 mg/dL, she was treated with IV dextrose and was discharged from the ED. She was referred to outpatient endocrinology for further evaluation where continuous glucose monitoring confirmed predominantly fasting hypoglycemia. Adrenal insufficiency was excluded. She was admitted for a 72 hour inpatient fast where the patient achieved hypoglycemia within 24 hours, with glucose 46 mg/dL (associated with neuroglycopenic symptoms), beta hydroxybutyrate < 0.18 mmol/L, insulin 3.9 mcIU/mL, proinsulin 157pmol/L, c-peptide 1.4 ng/mL and a glucose rise greater than 25mg/dL after glucagon administration. Sulfonylurea screen and insulin antibodies were negative; IGF1 within normal limits. These labs were consistent with hyperinsulinemic hypoglycemia. An MRI pancreas however did not reveal an insulinoma. The patient therefore underwent a SACST, demonstrating a 10 fold response in the territory of the gastroduodenal artery and splenic artery, as well as a 3 fold response in the superior mesenteric artery. This heterogenous pattern in addition to the marked response in each arterial territory raised the possibility of multiple insulinomas. However as there were no tumors present on imaging, medical management was initiated with close follow up. She was trialed with months of somatostatin analogs and diazoxide with minimal improvement in the frequency and severity of her hypoglycemia. About a year after her initial diagnosis, repeat abdominal imaging (CT and MRI) revealed an 8 mm arterial hyper-enhancing lesion in the body of the pancreas concerning for neuroendocrine tumor. Repeat SACST was performed, this time showing a greater than 10 fold response in all three arterial territories. Angiography showed a tumor blush that was visible when each of the three major arteries were injected sequentially. She underwent laparoscopic pancreatic enucleation. The lesion was located on the body of the pancreas, with histology confirming an insulinoma. The patient responded promptly post operatively; her symptoms resolved without further need of medical management. Conclusion: Our case shows that the interpretation of an SACST should take into account the arterial anatomy before ascribing a non-focal response to multiple territories of insulin hypersecretion. Presentation: 6/1/2024

7068 Paraganglioma in Cyanotic Congenital Heart Disease

Abstract Disclosure: R. Lis: None. V. Hamidi: None. Paragangliomas arise from the non-chromaffin cells of the parasympathetic nervous system, which are composed of glomus cells. These function as chemoreceptors in response to hypoxia. Carotid body paragangliomas have been linked to conditions with chronic hypoxia. This was first seen in residents of high altitude locations in a case report presented by Saldana et. al and regression of a paraganglioma with resolution of hypoxia was reported by Gruber et. al. There have been few additional case reports of Paraganglioma in other hypoxic states. We present a rare case of a functional Paraganglioma in a patient with Cyanotic Congenital Heart Disease (CCHD).This is a 19 year old female with a history of CCHD due to double inlet left ventricle and transposition of the great arteries. Soon after birth, she had a fontan procedure. She subsequently developed fontan associated liver disease as well as chronic kidney disease, hypertension, sinus node dysfunction, and complete heart block. Her baseline oxygen saturation was 78-85%. Her heart rate was 40-49 beats per minute with upcoming plans for pacemaker placement. Her blood pressure ranged 90/50 to 150/80 mmHg on Amlodipine 5 mg and Lisinopril 2.5 mg. She routinely received abdominal imaging to monitor her liver disease. A liver MRI incidentally revealed a retroperitoneal mass concerning for a paraganglioma. Serum Normetanephrines were found to be 26.60 nmol/L (reference range less than 0.89). 24 hr Urine Norepinephrine was 1,187 ug/d (reference range 14-20). Further imaging was negative for additional sites of disease. Given her complete heart block, she was started on alpha blockade only prior to pacemaker placement. After the pacemaker was placed, she was started on beta blockade and underwent surgical resection of her paraganglioma. The pathology confirmed paraganglioma and mutation testing was negative for germline mutations including SDH, VHL, RET, NF1 mutations. Paragangliomas in patients with CCHD have been scarcely described in the literature given the rarity of both of these conditions. However, there is a relatively increased incidence of paragangliomas in the CCHD population due to chronic hypoxia triggering the hypoxia pathway. EPAS1 mutated HIF2alpha is often found to be the culprit in these patients. In addition, case reports have often described these patients to either be asymptomatic or have potential symptoms masked by their cardiac disease. Therefore, CCHD patients are at increased risk for paragangliomas and warrant additional awareness and regular screening. Screening has been proposed to start after 10 years of hypoxia in a case review by Agarwal et. al. as paraganglioma incidence in CCHD populations has not been seen before age 11. Incidence of recurrence is not yet widely studied, but significant concern for recurrence is warranted if the etiology of hypoxia is not reversed. Presentation: 6/3/2024

8769 A Case of Metastatic and Catecholamine Producing Bilateral Pheochromocytoma in a Patient with RET Gene Mutation

Abstract Disclosure: R.A. Mayers: None. A. Szafran-Swietlik: None. RET mutation, observed in multiple endocrine neoplasia type 2 syndromes, is implicated in the development of pheochromocytomas of the kinase signaling cluster. Such tumors have lower metastatic risk and adrenergic production compared to the ones from the other clusters. We present a case of a metastatic, bilateral, small and biochemically active pheochromocytoma .This is the case of a 27-year-old man diagnosed with MEN 2A. He underwent total thyroidectomy due to medullary thyroid carcinoma at 2 years old. He was deemed cured and started on levothyroxine replacement. Since then, his plasma metanephrines by liquid chromatography-mass spectrometry and urine metanephrines done in a yearly basis as screening, were always within range of normality. Over the years, he developed substance abuse disorder with use of Kratom and methamphetamines and was admitted in a rehabilitation center multiple times in the last three years. During this time, the patient was reported to be slightly tachycardiac which was initially attributed to the use of substances. On the last year, an echocardiogram done as evaluation of his tachycardia showed an ejection fraction of 35%. Later, his annual metanephrine levels were markedly elevated (free metanephrine: 137 pg/mL and free normetanephrine : 157 pg/mL, normal ranges reported as less than 57 pg/mL and less than 148 pg/mL respectively). Abdominal tomography showed a right adrenal nodule of 1.2 cm and a left adrenal nodule of 1.6 cm, both with more than 10 Hounsfield Units. A Metaiodobenzylguanidine scan revealed a left adrenal nodule of 1.8 cm with diffuse radiotracer uptake, a right adrenal nodule of 1.2 cm with radiotracer activity and 3 subtle areas of focally increased radiotracer activity in the liver, two in left hepatic lobe and other in posterior right upper lobe. He underwent bilateral adrenalectomy with cortical sparring. Pathology results evidenced a left adrenal with a unifocal mass of 1.8 cm and a right adrenal with a mass of 1.2 cm , both without lymphovascular, capsular, local invasion or necrosis, a mitotic rate of 1-2 without atypical mitosis, not encapsulated with clean margins and positive for synaptophysin , chromogranin and S100 stains. An additional mass of 0.7 cm on the right adrenal gland was described with similar characteristics to the described before except for the involvement of the surgical margins. Currently on the literature there are different opinions regarding screening approach for pheochromocytomas in the presence of RET mutations. There are not strong recommendations regarding the use of imaging as a screening tool in this group of patients. It is important to consider that there are cases, as the one described in this report, that might present metastatic disease even with the presence of small pheochromocytomas that belong to the cluster of kinase signaling. Presentation: 6/3/2024

Abnormal enhancement of the diseased upper digestive tract shown on MRI

This review article describes the imaging techniques, interpretation, and findings of inflammatory changes in the upper digestive tract, including the distal esophagus, stomach, duodenum, jejunum, and ileum. These are the least understood of all abdominal imaging observations and, hence, rarely described in reports. Upper digestive tract imaging findings are poorly understood at present. An illustration of inflammation of all these segments is reported herein. MRI is the optimal technique for studying Leaky Gut, Irritable Bowel Syndrome, and Splanchnic Metabolic Syndrome. This opens new avenues of research and clinical interpretation.

S1751 Advanced Liver Disease Detected by Abdominal Imaging Does Not Lead to Linkage to Care in Hepatology Clinics or Uptake of Hepatocellular Carcinoma Screening in an Urban Center

S1751 Advanced Liver Disease Detected by Abdominal Imaging Does Not Lead to Linkage to Care in Hepatology Clinics or Uptake of Hepatocellular Carcinoma Screening in an Urban Center

Automated Segmentation of Individual Kidney Cysts in Routine Abdominal CT Images

Automated Segmentation of Individual Kidney Cysts in Routine Abdominal CT Images

Application of deep learning reconstruction in abdominal magnetic resonance cholangiopancreatography for image quality improvement and acquisition time reduction

PurposeTo compare deep learning (DL)-based and conventional reconstruction through subjective and objective analysis and ascertain whether DL-based reconstruction improves the quality and acquisition speed of clinical abdominal magnetic resonance imaging (MRI). MethodsThe 124 patients who underwent abdominal MRI between January and July 2021 were retrospectively studied. For each patient, two-dimensional axial T2-weighted single-shot fast spin-echo MRI images with or without fat saturation were reconstructed using DL-based and conventional methods. The subjective image quality scores and objective metrics, including signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of the images were analysed. An explorative analysis was performed to compare 20 patients’ MRI images with site routine settings, high-resolution settings and high-speed settings. Paired t tests and Wilcoxon signed-rank tests were used for subjective and objective comparisons. ResultsA total of 144 patients were evaluated (mean age, 62.2 ± 14.1 years; 83 men). The MRI images reconstructed using DL-based methods had higher SNRs and CNRs than did those reconstructed using conventional methods (all p < 0.01). The subjective scores of the images reconstructed using DL-based methods were higher than those of the images reconstructed using conventional methods (p < 0.01), with significantly lower variation (p < 0.01). Exploratory analysis revealed that the DL-based reconstructions with thin slice thickness and higher temporal resolution had the highest image quality and were associated with the shortest scan times. ConclusionsDL-based reconstruction methods can be used to improve the quality with higher stability and accelerate the acquisition of abdominal MRI.

Whole aorta imaging shows increased risk for thoracic aortic aneurysms and dilatations in relatives of abdominal aortic aneurysm patients

ObjectiveFor relatives of abdominal aortic aneurysm (AAA) patients, guidelines recommend abdominal imaging aimed at early detection and management of AAA, and do not include screening for thoracic aortic aneurysms (TAA). We aimed to investigate if TAA occur in undiagnosed relatives of AAA patients without a known genetic susceptibility for aneurysms, similar to families with identified genetic susceptibilities for aneurysms like in Marfan and Loeys-Dietz syndrome, where both AAA and TAA occur. MethodsRelatives of AAA patients were invited for non-contrast whole aorta CT screening. Systematic measurements of the CT scans were used to detect aneurysms and dilatations. Classification into familial and non-familial was based on reported family histories. In addition, aneurysm gene panel testing of AAA index cases was used for the classification of high vs unknown genetic risk (high genetic risk: familial aneurysm or a (likely) pathogenic variant (P/LP) in an aneurysm gene; unknown genetic risk: no family history or P/LP). ResultsWhole aorta imaging of 301 relatives of 115 abdominal aortic aneurysm index-patients with non-contrast CT scans showed a 28-fold increase in thoracic aortic aneurysms in relatives (1.7%, p<0.001 versus the age adjusted population) and a high frequency of thoracic dilatations in 18% of the relatives. Thoracic aneurysms and dilatations in relatives occurred even when index patients were unaware of familial aneurysms. AAA was increased in the relatives compared to the age adjusted population (8%, p<0.001). ConclusionsAn increased risk for thoracic aneurysms and dilatations was detected by whole aorta imaging of relatives of AAA index patients, even when index patients were unaware of familial aneurysms.These results indicate -still unknown- shared genetic susceptibilities for thoracic and abdominal aneurysms. Therefore, imaging of the whole aorta of relatives of all abdominal aneurysm patients, will improve early detection of aortic aneurysms in relatives of all AAA patients.

S1119 How Good Does a Risk Calculator Need to Be to Triage Abdominal Imaging of Crohn’s Disease in the Emergency Department?

S1119 How Good Does a Risk Calculator Need to Be to Triage Abdominal Imaging of Crohn’s Disease in the Emergency Department?

The Spectrum of Adrenal Lesions in a Tertiary Referral Center.

Adrenal tumors are a common finding in clinical practice, and only detailed evaluation may reveal secretory and metabolic abnormalities or their malignant character. We aimed to highlight epidemiological data, rates of malignancy, clinical or secretory characteristics, and the cardiometabolic implications of adrenal masses. We conducted a retrospective analysis using data from the medical files of 474 patients with adrenal pathology hospitalized between January 2007 and January 2020, before the COVID-19 pandemic, using the ICD-10 codes. After applying inclusion and exclusion criteria, a total of 264 patients with adrenal tumors were enrolled in the study. Patients underwent clinical examination, abdominal imaging, and hormonal evaluation, and some of them underwent a pathological exam after adrenalectomy. Median age at diagnosis was 56 (17) years, with 81.06% of patients being female. The median follow-up period was 41.5 (70) months, ranging from 6 months to 13 years. Adrenal tumors were most frequently seen in older female patients, with 83.47% of them being over 40 years old. The malignancy rate was 4.54%. Hormonally nonfunctioning tumors (71.95%) predominated, and overt hypercortisolism was present in 10.61% of patients, as was mild autonomous cortisol secretion in 5.31% of patients, primary hyperaldosteronism in 8.71% of patients, and adrenal paraganglioma in 3.41% of patients. Cardiometabolic comorbid conditions were similar in patients with functioning and nonfunctioning tumors. All patients with adrenal tumors should receive a complete hormonal workup and detailed malignancy risk assessment. Even though a hormonally active tumor predisposes to cardiometabolic comorbid conditions, a nonfunctioning lesion may also be associated with such disorders and needs thorough assessment.

DELR-Net: a network for 3D multimodal medical image registration in more lightweight application scenarios.

3D multimodal medical image deformable registration plays a significant role in medical image analysis and diagnosis. However, due to the substantial differences between images of different modalities, registration is challenging and requires high computational costs. Deep learning-based registration methods face these challenges. The primary aim of this paper is to design a 3D multimodal registration network that ensures high-quality registration results while reducing the number of parameters. This study designed a Dual-Encoder More Lightweight Registration Network (DELR-Net). DELR-Net is a low-complexity network that integrates Mamba and ConvNet. The State Space Sequence Module and the Dynamic Large Kernel block are used as the main components of the dual encoders, while the Dynamic Feature Fusion block is used as the main component of the decoder. This study conducted experiments on 3D brain MR images and abdominal MR and CT images. Compared to existing registration methods, DELR-Net achieved better registration results while maintaining a lower number of parameters. Additionally, generalization experiments on other modalities showed that DELR-Net has superior generalization capabilities. DELR-Net significantly improves the limitations of 3D multimodal medical image deformable registration, achieving better registration performance with fewer parameters.

Longitudinal intravital microscopy of the mouse kidney: inflammatory responses to abdominal imaging windows.

Intravital microscopy enables direct observation of cell biology and physiology at subcellular resolution in real time in living animals. Implanted windows extend the scope of intravital microscopy to processes extending for weeks or even months, such as disease progression or tumor development. However, a question that must be addressed in such studies is whether the imaging window, like any foreign body, triggers an inflammatory response, and if that response alters the biological process under investigation. To directly evaluate this question, we conducted large-scale intravital microscopy of the kidney of LysM-EGFP mice over time after implantation of abdominal imaging windows. These studies demonstrate that windows stimulated a variety of changes consistent with a foreign body response. Within a few days of implantation, leukocytes were recruited to the window and the region between the window and kidney where, over the next 16 days, they increased in number in an expanding volume that developed a new vascular network. These changes were accompanied by a dramatic increase in glomerular albumin permeability within 2 - 5 days of implantation. Similar results were obtained from mice implanted with windows coated with PLL-g-PEG, but not from immune-deficient mice. These studies demonstrate the importance of evaluating whether implanted windows induce an inflammatory response, and whether that response impacts the processes under evaluation in longitudinal intravital microscopy studies.

The Clinical Significance of Pancreatic Steatosis in Pancreatic Cancer: A Hospital-Based Study.

Background/Objectives: Pancreatic cancer remains one of the deadliest malignancies worldwide with a pressing need for early detection and intervention strategies. Emerging evidence has suggested a potential link between pancreas steatosis, characterized by excessive pancreatic fat accumulation, and an increased risk of pancreatic cancer development. This retrospective imaging study aims to elucidate the association between pancreatic steatosis and the subsequent development of pancreatic cancer. In the study, we aimed to determine the characteristics of pancreatic cancer with pancreatic steatosis. Methods: During the period of January 2022 to December 2022, we conducted a retrospective study, collecting 101 newly diagnosed pancreas cancer cases from the available image datasets. A comprehensive database of retrospective abdominal imaging studies, comprising computed tomography (CT) and magnetic resonance imaging (MRI), was established from a diverse patient population and subsequently analyzed. Inclusion criteria encompassed patients having available baseline imaging data, allowing for the assessment of pancreatic fat content. Pancreatic fat content was quantified using validated radiological techniques, while demographic, clinical, and histopathological data were all collected. The clinical data and patient characteristics were collected from medical records and analyzed. Results: Preliminary analysis revealed a significant correlation between elevated pancreatic fat content and an increased incidence of subsequent pancreatic cancer. Moreover, subgroup analysis based on age, gender, and comorbidities provided valuable insight into potential risk factors associated with this progression. Additionally, the study identified novel radiological markers that may serve as early indicators of pancreatic cancer development in individuals with pancreatic steatosis. Conclusions: In the imaging study, approximately 30% (30/101) of pancreatic cancer patients presented with pancreatic steatosis. Chronic pancreatitis emerged as the primary factor contributing to pancreatic steatosis in these patients. Importantly, pancreatic steatosis did not significantly impact the prognosis of pancreatic cancer. Follow-up data revealed no significant differences in survival duration between patients with or without pancreatic steatosis. Additionally, no association was found between pancreatic steatosis and hepatic steatosis.

Diagnosis of newly developed multiple myeloma without bone disease detectable on conventional computed tomography (CT) scan by using dual-energy CT

ObjectiveTo evaluate the diagnostic utility of fat (hydroxyapatite) density [DFat (HAP)] on dual-energy computed tomography (DECT) for identifying clinical diagnosed multiple myeloma without bone disease (MNBD) that is not visible on conventional CT scans. Material and MethodsIn this age-gender-examination sites matched case control prospective study, Chest and/or abdominal images on Revolution CT of MNBDs and control subjects were consecutive enrolled in a 1:2 ratio from October 2022 to November 2023. Multiple myeloma was clinical diagnosed according to criteria of the International Myeloma Working Group. Regions of interest (ROIs) were drawn separately for all thoracolumbar vertebrae in the scanning range by two radiologists. Additionally, a radiologist specializing in musculoskeletal imaging supervised the process. DFat (HAP) was extracted from each ROI. The spine was divided into upper thoracic (UPT), middle and lower thoracic (MLT), thoracolumbar (TL), and middle and lower lumbar (MLL) vertebrae. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the diagnostic performance of DFat (HAP) in diagnosing multiple myeloma, and the sensitivity, specificity, and accuracy under the optimal cut-off were determined by Youden index (sensitivity + specificity −1). ResultsA total of 32 and MNBD patients and 64 control patients were included. The total number of ROIs outlined included MNBD group (n = 493) and control group (n = 986). For all vertebrae, DFat(HAP) got average performance in the diagnosis of MNBD (AUC = 0.733, p < 0.001) with a cut-off value of 958 (mg/cm3); the sensitivity, specificity, and accuracy were 58.8 %, 77.8 %, and 71.7 %, respectively. Regarding segment analysis, the diagnostic performance was good for all (AUC, 0.803–0.837; p < 0.001) but the UPT segment (AUC = 0.692, p = 0.002). The optimal diagnostic cut-off values for the MLT, TL, and MLL vertebrae were 955 mg/cm3, 947 mg/cm3, and 947 mg/cm3, respectively; the sensitivity, specificity, and accuracy were 80.0 %-87.5 %, 71.9 %-82.6 %, and 77.1 %-81.6 %, respectively. ConclusionDECT was effective for detecting MNBD, and better diagnostic results can be obtained by grouping different spine segments.

Enhancing Diagnostic Accuracy in Body Packing Cases: The Impact of Preliminary Diagnosis Awareness on Computed Tomography Evaluation

Objective: Body packing refers to the concealment of illegal substances within the body. This study aims to evaluate the computed tomography (CT) findings of body packing cases, and to assess whether considering the possibility of body packing in preliminary diagnosis will affect the accuracy of specialists evaluating in the emergency and intensive care departments. Materials and Methods: 20 body packing cases were retrospectively examined for the presence of foreign bodies. A control group was created from 20 non-contrast abdominal CT images. Re-evaluation involved four radiologists. Before evaluating, two radiologists were advised they could be body packers. Results: In 18 (90%) of 20 body packers, foreign bodies were visible in the intestinal lumen, mostly 14 (70%) in the colon. Radiologists who were given preliminary diagnosis, correctly identified all 18 (100%) intestinal foreign body cases and did not make any false positives. Two other radiologists correctly identified 16 (88.9%) cases and missed 2 (11.1%) cases and there was significantly difference (p

Interactions between muscle volume and body mass index on brain structure in the UK Biobank.

Low skeletal muscle volume may increase dementia risk through mechanisms affecting brain structure. However, it is unclear whether this relationship exists outside of sarcopenia and/or varies by other factors. We aimed to study the interplay between skeletal muscle volume and factors, such as age, sex, and body mass index (BMI), in explaining brain structure at midlife in a cohort without sarcopenia. We used abdominal and brain magnetic resonance imaging (MRI) data from a population-based cohort enrolled in the UK Biobank. The following measures were derived: thigh fat-free muscle volume (FFMV), total brain volume (TBV), gray matter volume (GMV), white matter volume (WMV), total hippocampal volume (THV), and white matter hyperintensity volume (WMHV). Participants below sex-based grip strength thresholds suggesting probable sarcopenia were excluded. Linear regression analysis was used to study the interaction or mediation effects of age, sex, and BMI on the associations between FFMV and brain volumes. Data were available for 20,353 participants (median age 64 years, 53% female). We found interactions between thigh FFMV, BMI, and age (all p < 0.05). Greater thigh FFMV was associated with better brain volumes in those aged <64 years with normal (TBV: β = 2.0 ml/L, p = 0.004; GMV: β = 0.8 ml/L, p = 0.04; WMV: β = 1.1 ml/L, p = 0.006; WMHV: β = -0.2 ml/L, p = 3.7 × 10-5) or low BMI (TBV: β = 21.2 ml/L, p = 0.003; WMV: β = 13.3 ml/L, p = 0.002, WMHV: β = -1.1 ml/L, p = 0.04). Greater thigh muscle volume correlates with better brain volumes at midlife in people without sarcopenia, but this relationship weakens with greater age and BMI. Further study is required to investigate the underlying mechanisms to understand which components of body composition are potentially modifiable risk factors for dementia.

Visceral and subcutaneous adiposity and cardiovascular disease: Unravelling associations and prognostic value.

The distribution pattern of abdominal adiposity may help determine cardiovascular disease (CVD). Waist circumference (WC) is the most common but imprecise method for measuring abdominal adiposity, as it fails to differentiate between visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (ASAT). This study aimed to determine whether elevated VAT or ASAT provides greater prognostic value for CVD events compared to elevated WC in the general population using data from the UK Biobank. In this secondary analysis of UK Biobank study, 24 265 participants with available abdominal magnetic resonance imaging data were included. The primary outcome of the study was coronary heart disease (CHD), and secondary outcomes included stroke, heart failure (HF) and atrial fibrillation (AF). Cox regressions for VAT, ASAT and WC were examined in relation to the predefined outcomes on continuous scales using standard deviation (SD) changes and by categories of concordant and discordant values defined by medians. During a mean follow-up period of 12.9 ± 1.8 years, 2641 participants developed CVD events (1296 CHD, 165 stroke, 286 HF and 894 AF) Each 1 SD increase in VAT yielded a hazard ratio (HR) of 1.15 (95% confidence interval [CI]: 1.09-1.22) for CHD risk, whereas ASAT had a HR of 1.10 (95% CI: 1.04-1.18). Further adjustment for WC eliminated the association between ASAT and CHD risk, in contrast to the association between VAT and CHD risk, which remained almost unaffected. Discordant VAT above the median with WC below presented a HR of 1.43 (95% CI: 1.15-1.78) for CHD, compared with concordant VAT and WC below the median. Similar results were found for discordant WC above the median with VAT below, with a HR of 1.46 (95% CI: 1.18-1.81). In contrast, discordant ASAT above the median with WC below was not associated with an increased risk of CHD. Similarly, discordant ASAT above the median with VAT below was not associated with an increased risk of CHD. Additionally, there was no observed association between VAT or ASAT and the risks of stroke, HF or AF after further adjustment for WC. Additionally, there was no observed association between VAT or ASAT and the risks of stroke, HF or AF after further adjustment for WC. Incorporating VAT measurements alongside WC data improved the ability to identify individuals at high risk for CHD compared to using WC alone. Both VAT and WC proved to be more accurate indicators of CHD risk than ASAT. However, VAT alone did not fully account for the CHD risk associated with elevated WC levels. Neither VAT nor ASAT showed an association with the risk of stroke, HF and AF.

Tuberculosis masquerading as a pancreatic cyst in a patient with cirrhosis

Cystic lesions of the pancreas are being increasingly diagnosed incidentally in recent decades due to easy availability of abdominal imaging. They may be neoplastic or benign. Tuberculosis, the great masquerader, may rarely involve the pancreas mimicking pancreatic malignancy, cyst, or abscess. Identification of this rare entity is crucial to avoid potentially risky surgery as anti-tubercular pharmacotherapy is highly effective. We report a case of a 40-year old cirrhotic man who presented with a cystic hypodense lesion in the pancreatic tail and was subsequently diagnosed with pancreatic tuberculosis. Apart from the rarity of diagnosis, our case also highlights the utility of endoscopic ultrasound for minimally invasive assessment of pancreatic lesions.

Comparison of Conventional and Virtual Non-contrast Abdominal Images Using the Third-Generation Dual-Source Dual-Energy Computed Tomography.

To determine the efficacy and safety of virtual unenhanced imaging by comparing the attenuation values of virtual and true unenhanced images acquired using third-generation dual-source dual-energy computed tomography (dsDECT). Single-energy non-contrast and dual-energy arterial and venous phase images of 97 patients who underwent triphasic abdominal computed tomography (CT) were included in this retrospective study. Virtual unenhanced images were generated for the arterial (a) and venous (v) phases using two dsDECT algorithms. The attenuation values were measured on the true and virtual unenhanced images of the liver, spleen, kidney, gallbladder, paraspinal muscle, aorta, subcutaneous fat, retroperitoneal fat, and renal cysts. A statistically significant difference was observed between the attenuation values ​​of true and virtual unenhanced images for all tissues (p < 0.001-0.025), except the venous phase virtual unenhanced images of the kidney, renal cysts, and gallbladder (p = 0.061-0.325). The proportion of cases with differences of ≥ 10 Hounsfield unit (HU) in the attenuation values between the virtual and true unenhanced images ranged from 3% to 8% for renal parenchyma, renal cysts, and gallbladder using this algorithm; however, this proportion was up to 90% for adipose tissue. No significant correlation was observed between the body mass index and attenuation differences between the true and virtual unenhanced images, except for those of the aorta and paraspinal muscle. Virtual unenhanced images acquired using third-generation dsDECT cannot replace true unenhanced images in clinical practice owing to the difference between the attenuation values and variability of attenuation between true and virtual unenhanced images.

Abstract A161: Racial and ethnic differences in receipt of guideline-recommended hepatocellular carcinoma surveillance in a high Risk, diverse primary care patient population: A study in two large integrated healthcare systems in California and Hawai‘i

Abstract Guideline-recommended ultrasounds for hepatocellular carcinoma (HCC) surveillance target patients with cirrhosis and certain liver conditions, yet uptake remains low, particularly among racial/ethnic minority groups. Underuse may be attributed to factors at the patient, provider, healthcare system, and neighborhood levels. However, in-depth analyses identifying contributory factors are lacking. We investigated the presence of racial/ethnic disparities in receipt of recommended surveillance among high-risk patients as a retrospective analysis of electronic health record (EHR) data from Kaiser Permanente Hawai‘i (KPHI) and Sutter Health in California, both of which serve numerous Asian American, Hispanic, Native Hawaiian (NH), other Pacific Islander (PI), and multiracial/ethnic patients. We included patients with ≥1 in-person encounter (2000-2017), no history of liver cancer, and a clinical indication of surveillance eligibility (cirrhosis, chronic hepatitis B or C, or a high FIB-4 score ≥2.67) with a minimum EHR follow-up of 18 months post-eligibility. Recommended surveillance is biannual abdominal imaging (ultrasound, CT, MRI) or alpha-1 fetoprotein tests. We categorized eligible patients as 'ever surveilled' if conducted at least once during follow-up and by the proportion of follow-up time they were up-to-date with surveillance (PTUDS). The cohort includes 54,597 patients (9,488 from KPHI; 45,109 from Sutter); current results are for the KPHI subset only. Among N=9,488 patients (median age: 52; 46% female; 26% NHW, 14% NH, 11% Filipino, 10% multiracial/ethnic) median follow-up was 91 months and 82% were surveilled at least once, with a mean PTUDS of 14% (SD=19%) overall and 19% (SD=21%) among the surveilled. We used sex- and age-adjusted log-risk regression for risk ratio (RR) of ‘ever surveilled’ vs. not and linear regression for PTUDS; NHW is the reference group in all models. We found that NH (RR=0.96, 95%CI 0.93-1.00), PI (RR=0.91, 95%CI 0.97-0.95) and multiracial/ethnic (RR=0.95, 95%CI 0.91-0.99) patients were significantly less likely to be ever surveilled, and that PI (beta=-0.02, 95% CI -0.04-0.01) race/ethnicity was significantly associated with lower PTUDS, while Chinese (beta=0.04, 95% CI 0.02-0.06), Korean (beta=0.04, 95%CI 0.01-0.07), Vietnamese (beta=0.05, 95%CI 0.02-0.09), and other Asian (beta=0.03, 95%CI 0.00-0.07) ethnicities were significantly associated with higher PTUDS. Although not statistically significant, surveillance rates were lower for American Indian/Alaska Native and Black groups, and higher for Japanese and Non-Hispanic Other race/ethnicity groups. Continued analyses will incorporate Sutter data, employ fully adjusted models with clustering by health system, and examine patient, provider, and neighborhood drivers of these disparities. Our findings indicate racial/ethnic disparities in HCC surveillance receipt, particularly noting the heterogeneity within Asian populations, and underscore the importance of analyzing disaggregated data for Asian American groups to fully understand and address these disparities. Citation Format: Enyao Y. Zhang, Mindy DeRouen, Alison J. Canchola, Aly M. Cortella, Pushkar Inamdar, Janet N. Chu, Sixiang Nie, Mai Vu, Ma Somsouk, Michele M. Tana, Anna D. Rubinsky, Iona Cheng, Mi-Ok Kim, Mark Segal, Chanda Ho, Yihe G. Daida, Su-Ying Liang, Hashem B. El-Serag, Scarlett L. Gomez, Salma Shariff-Marco, Caroline A. Thompson. Racial and ethnic differences in receipt of guideline-recommended hepatocellular carcinoma surveillance in a high Risk, diverse primary care patient population: A study in two large integrated healthcare systems in California and Hawai‘i [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A161.