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Background: To establish dual-energy-derived iodine density reference values in abdominopelvic organs in a large cohort of healthy subjects. Methods: 597 patients who underwent portal venous phase dual-energy CT scans of the abdomen were retrospectively enrolled. Iodine distribution maps were reconstructed, and regions of interest measurements were placed in abdominal and pelvic structures to obtain absolute iodine values. Subsequently, normalization of the abdominal aorta was conducted to obtain normalized iodine ratios. The values obtained were subsequently analyzed and differences were investigated in subgroups defined by sex, age and BMI. Results: Overall mean iodine uptake values and normalized iodine ratios ranged between 0.31 and 6.08 mg/mL and 0.06 and 1.20, respectively. Women exhibited higher absolute iodine concentration across all organs. With increasing age, normalized iodine ratios mostly tend to decrease, being most significant in the uterus, prostate, and kidneys (p < 0.015). BMI was the parameter less responsible for variations in iodine concentrations; normal weighted patients demonstrated higher values of both absolute and normalized iodine. Conclusions: Iodine concentration values and normalized iodine ratios of abdominal and pelvic organs reveal significant gender-, age-, and BMI-related differences, underscoring the necessity to integrate these variables into clinical practice. [ABSTRACT FROM AUTHOR]

Small bowel obstruction (SBO) is a common condition encountered by radiologists in the evaluation of patients with abdominal pain, and is an important diagnosis to be comfortable with given substantial associated morbidity and mortality. In this review, we summarize an imaging approach to evaluating patients with suspected SBO, discuss the role of certain imaging modalities such as radiography and small bowel follow through, CT, and MRI, as well as review some common and also less common causes of SBO such as internal hernia. We will also discuss tailoring the imaging approach to address specific clinical questions and special patient populations such as imaging the pregnant patient with suspected SBO, and the inflammatory bowel disease patient. [ABSTRACT FROM AUTHOR]

This study aims to assess the quality of abdominal MR images acquired on a commercial 0.55T scanner and compare these images with those acquired on conventional 1.5T/3T scanners in both healthy subjects and patients. Fifteen healthy subjects and 52 patients underwent abdominal Magnetic Resonance Imaging at 0.55T. Images were also collected in healthy subjects at 1.5T, and comparison 1.5/3T images identified for 28 of the 52 patients. Image quality was rated by two radiologists on a 4-point Likert scale. Readers were asked whether they could answer the clinical question for patient studies. Wilcoxon signed-rank test was used to test for significant differences in image ratings and acquisition times, and inter-reader reliability was computed. The overall image quality of all sequences at 0.55T were rated as acceptable in healthy subjects. Sequences were modified to improve signal-to-noise ratio and reduce artifacts and deployed for clinical use; 52 patients were enrolled in this study. Radiologists were able to answer the clinical question in 52 (reader 1) and 46 (reader 2) of the patient cases. Average image quality was considered to be diagnostic (>3) for all sequences except arterial phase FS 3D T1w gradient echo (GRE) and 3D magnetic resonance cholangiopancreatography for one reader. In comparison to higher field images, significantly lower scores were given to 0.55T IP 2D GRE and arterial phase FS 3D T1w GRE, and significantly higher scores to diffusion-weighted echo planar imaging at 0.55T; other sequences were equivalent. The average scan time at 0.55T was 54 ± 10 minutes vs 36 ± 11 minutes at higher field strengths (P <.001). Diagnostic-quality abdominal MR images can be obtained on a commercial 0.55T scanner at a longer overall acquisition time compared to higher field systems, although some sequences may benefit from additional optimization. [ABSTRACT FROM AUTHOR]

Chromobacterium violaceum is associated with severe sepsis leading to cutaneous and visceral organ abscesses, with mortality rates up to 73%. Around 200 cases of C. violaceum infection have been reported globally. We report a case of a 27-year-old female U.S. Marine recruit who presented with fever, chills, myalgias, arthralgias, headache, and nodules on her extremities. Physical examination revealed multiple small skin abscesses on her extremities. Abdominal imaging with contrast revealed large liver abscesses requiring drainage. Both blood and wound cultures grew C. violaceum. The patient was successfully treated with meropenem and ciprofloxacin. At 3 months, symptoms had resolved, and labs and imaging were normal. Though rare, C. violaceum infection rates are increasing. Severe infection develops rapidly and invasive disease is not uncommon. Early detection and appropriate antibiotic treatment are key in preventing mortality. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma–cholangiocarcinoma (cHCC–CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)–CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA. [ABSTRACT FROM AUTHOR]

Purpose: Photon-counting detector CT (PCD CT) is a promising technology for abdominal imaging due to its ability to provide high spatial and contrast resolution images with reduced patient radiation exposure. However, there is currently no consensus regarding the optimal imaging protocols for PCD CT. This article aims to present the PCD CT abdominal imaging protocols used by two tertiary care academic centers in the United States. Methods: A review of PCD CT abdominal imaging protocols was conducted by two abdominal radiologists at different academic institutions. Protocols were compared in terms of acquisition parameters and reconstruction settings. Both imaging centers independently selected similar protocols for PCD CT abdominal imaging, using QuantumPlus mode. Results: There were some differences in the use of reconstruction kernels and iterative reconstruction levels, however the individual combination at each site resulted in similar image impressions. Overall, the imaging protocols used by both centers provide high-quality images with low radiation exposure. Conclusion: These findings provide valuable insights into the development of standardized protocols for PCD CT abdominal imaging, which can help to ensure consistent as well as high-quality imaging across different institutions and allow for future multicenter research collaborations. [ABSTRACT FROM AUTHOR]

To evaluate demographics, academic backgrounds, and scholarly activities of Program Directors (PDs) in Abdominal Imaging Fellowships in the United States (US), emphasizing gender representation, international origins, and academic milestones. A list of Fellowships in Abdominal Imaging programs in the US was obtained from the Society of Abdominal Radiology. The search was expanded using the Fellowship and Residency Electronic Interactive Database. Data for PDs were sourced from program websites, Healthgrades, Doximity, and Elsevier's Scopus. Metrics such as age, gender, education, academic rank, additional qualifications, prior leadership roles, publications, and h-indices were analyzed using R software. A two-tailed unpaired t-test was used to calculate the difference in means of scholarly activity between male and female PDs. 113 programs were identified: South (36.28%), Northeast (25.66%), Mid-West (20.35%), West (17.69%). Of 107 PDs, 54% male, 41% female, and average age 48 ± 9.4 years. 66.6% were US graduates, 29.2% were international graduates. Most were Assistant Professors (36.28%). 19.46% had degrees like M.P.H. or M.B.A. 45% had prior leadership roles. Average year of residency graduation was 2007. Mean publication count was 54.16, and mean h-index was 14.663. Male PDs had higher publication counts and h-indices than female PDs (p= 0.009 and p= 0.0019 respectively). In Abdominal Imaging Fellowship programs in the US, there is an increasing representation of females in Program Director roles. However, research led by female PDs remains less prevalent. The field of Abdominal Imaging values contributions from international graduates and insights from Assistant Professors. [ABSTRACT FROM AUTHOR]

Purpose: Improving the quality and maintaining the fidelity of large coverage abdominal hyperpolarized (HP) 13C MRI studies with a patch based global–local higher‐order singular value decomposition (GL‐HOVSD) spatiotemporal denoising approach. Methods: Denoising performance was first evaluated using the simulated [1‐13C]pyruvate dynamics at different noise levels to determine optimal kglobal and klocal parameters. The GL‐HOSVD spatiotemporal denoising method with the optimized parameters was then applied to two HP [1‐13C]pyruvate EPI abdominal human cohorts (n = 7 healthy volunteers and n = 8 pancreatic cancer patients). Results: The parameterization of kglobal = 0.2 and klocal = 0.9 denoises abdominal HP data while retaining image fidelity when evaluated by RMSE. The kPX (conversion rate of pyruvate‐to‐metabolite, X = lactate or alanine) difference was shown to be <20% with respect to ground‐truth metabolic conversion rates when there is adequate SNR (SNRAUC > 5) for downstream metabolites. In both human cohorts, there was a greater than nine‐fold gain in peak [1‐13C]pyruvate, [1‐13C]lactate, and [1‐13C]alanine apparent SNRAUC. The improvement in metabolite SNR enabled a more robust quantification of kPL and kPA. After denoising, we observed a 2.1 ± 0.4 and 4.8 ± 2.5‐fold increase in the number of voxels reliably fit across abdominal FOVs for kPL and kPA quantification maps. Conclusion: Spatiotemporal denoising greatly improves visualization of low SNR metabolites particularly [1‐13C]alanine and quantification of [1‐13C]pyruvate metabolism in large FOV HP 13C MRI studies of the human abdomen. [ABSTRACT FROM AUTHOR]

Emphysematous cholecystitis is a potentially life-threatening variant of acute cholecystitis, characterized by the presence of gas in the gallbladder wall/lumen due to the proliferation of gas-producing bacteria. Symptoms include upper right quadrant pain, fever, nausea, and vomiting. Laboratory tests may show nonspecific indications of systemic infection, and radiological assessment, especially CT scanning, is crucial for diagnosis. This case underscores the significance of early diagnosis and intervention in managing emphysematous cholecystitis to prevent serious complications and reduce the higher mortality rate compared to acute cholecystitis.

Abstract Purpose Unenhanced abdominal CT constitutes the diagnostic standard of care in suspected urolithiasis. Aiming to identify potential for radiation dose reduction in this frequent imaging task, this experimental study compares the effect of spectral shaping and tube voltage modulation on image quality. Methods Using a third-generation dual-source CT, eight cadaveric specimens were scanned with varying tube voltage settings with and without tin filter application (Sn 150, Sn 100, 120, 100, and 80 kVp) at three dose levels (3 mGy: standard; 1 mGy: low; 0.5 mGy: ultralow). Image quality was assessed quantitatively by calculation of signal-to-noise ratios (SNR) for various tissues (spleen, kidney, trabecular bone, fat) and subjectively by three independent radiologists based on a seven-point rating scale (7 = excellent; 1 = very poor). Results Irrespective of dose level, Sn 100 kVp resulted in the highest SNR of all tube voltage settings. In direct comparison to Sn 150 kVp, superior SNR was ascertained for spleen (p ≤ 0.004) and kidney tissue (p ≤ 0.009). In ultralow-dose scans, subjective image quality of Sn 100 kVp (median score 3; interquartile range 3–3) was higher compared with conventional imaging at 120 kVp (2; 2–2), 100 kVp (1; 1–2), and 80 kVp (1; 1–1) (all p

Background: To establish dual-energy-derived iodine density reference values in abdominopelvic organs in a large cohort of healthy subjects. Methods: 597 patients who underwent portal venous phase dual-energy CT scans of the abdomen were retrospectively enrolled. Iodine distribution maps were reconstructed, and regions of interest measurements were placed in abdominal and pelvic structures to obtain absolute iodine values. Subsequently, normalization of the abdominal aorta was conducted to obtain normalized iodine ratios. The values obtained were subsequently analyzed and differences were investigated in subgroups defined by sex, age and BMI. Results: Overall mean iodine uptake values and normalized iodine ratios ranged between 0.31 and 6.08 mg/mL and 0.06 and 1.20, respectively. Women exhibited higher absolute iodine concentration across all organs. With increasing age, normalized iodine ratios mostly tend to decrease, being most significant in the uterus, prostate, and kidneys (p < 0.015). BMI was the parameter less responsible for variations in iodine concentrations; normal weighted patients demonstrated higher values of both absolute and normalized iodine. Conclusions: Iodine concentration values and normalized iodine ratios of abdominal and pelvic organs reveal significant gender-, age-, and BMI-related differences, underscoring the necessity to integrate these variables into clinical practice.

Purpose: Unenhanced abdominal CT constitutes the diagnostic standard of care in suspected urolithiasis. Aiming to identify potential for radiation dose reduction in this frequent imaging task, this experimental study compares the effect of spectral shaping and tube voltage modulation on image quality. Methods: Using a third-generation dual-source CT, eight cadaveric specimens were scanned with varying tube voltage settings with and without tin filter application (Sn 150, Sn 100, 120, 100, and 80 kVp) at three dose levels (3 mGy: standard; 1 mGy: low; 0.5 mGy: ultralow). Image quality was assessed quantitatively by calculation of signal-to-noise ratios (SNR) for various tissues (spleen, kidney, trabecular bone, fat) and subjectively by three independent radiologists based on a seven-point rating scale (7 = excellent; 1 = very poor). Results: Irrespective of dose level, Sn 100 kVp resulted in the highest SNR of all tube voltage settings. In direct comparison to Sn 150 kVp, superior SNR was ascertained for spleen (p ≤ 0.004) and kidney tissue (p ≤ 0.009). In ultralow-dose scans, subjective image quality of Sn 100 kVp (median score 3; interquartile range 3–3) was higher compared with conventional imaging at 120 kVp (2; 2–2), 100 kVp (1; 1–2), and 80 kVp (1; 1–1) (all p < 0.001). Indicated by an intraclass correlation coefficient of 0.945 (95% confidence interval: 0.927–0.960), interrater reliability was excellent. Conclusions: In abdominal CT with maximised dose reduction, tin prefiltration at 100 kVp allows for superior image quality over Sn 150 kVp and conventional imaging without spectral shaping. [ABSTRACT FROM AUTHOR]

Introduction: Magnetic resonance elastography (MRE) is a non-invasive method to quantify biomechanical properties of human tissues. It has potential in diagnosis and monitoring of kidney disease, if established in clinical practice. The interplay of flow and volume changes in renal vessels, tubule, urinary collection system and interstitium is complex, but physiological ranges of in vivo viscoelastic properties during fasting and hydration have never been investigated in all gross anatomical segments simultaneously. Method: Ten healthy volunteers underwent two imaging sessions, one following a 12-hour fasting period and the second after a drinking challenge of >10 mL per kg body weight (60--75 min before the second examination). High-resolution renal MRE was performed using a novel driver with rotating eccentric mass placed at the posterior-lateral wall to couple waves (50 Hz) to the kidney. The biomechanical parameters, shear wave speed (cs in m/s), storage modulus (Gd in kPa), loss modulus (Gl in kPa), phase angle 2 π atan Gl Gd and attenuation (α in 1/mm) were derived. Accurate separation of gross anatomical segments was applied in post-processing (whole kidney, cortex, medulla, sinus, vessel). Results: High-quality shear waves coupled into all gross anatomical segments of the kidney (mean shear wave displacement: 163 ± 47 μm, mean contamination of second upper harmonics <23%, curl/divergence: 4.3 ± 0.8). Regardless of the hydration state, median Gd of the cortex and medulla (0.68 ± 0.11 kPa) was significantly higher than that of the sinus and vessels (0.48 ± 0.06 kPa), and consistently, significant differences were found in cs,, and Gl (all p < 0.001). The viscoelastic parameters of cortex and medulla were not significantly different. After hydration sinus exhibited a small but significant reduction in median Gd by 0.02 ± 0.04 kPa (p = 0.01), and, consequently, the cortico-sinusoidaldifference in Gd increased by 0.04 ± 0.07 kPa (p = 0.05). Only upon hydration, the attenuation in vessels became lower (0.084 ± 0.013 1/mm) and differed significantly from the whole kidney (0.095 ± 0.007 1/mm, p = 0.01). Conclusion: High-resolution renal MRE with an innovative driver and well-defined 3D segmentation can resolve all renal segments, especially when including the sinus in the analysis. Even after a prolonged hydration period the approach is sensitive to small hydration-related changes in the sinus and in the corticosinusoidal- difference. [ABSTRACT FROM AUTHOR]

Splenic rupture in a neonate is a rare but potentially fatal condition that may trigger evaluation for child abuse. It is a diagnosis of exclusion that has been reported in the surgical literature but may be underrecognized by pediatric radiologists. We report a case of a newborn with an unremarkable prenatal, delivery, and nursery course who presented with anemia, abdominal distension, and lethargy. Abdominal ultrasound with Doppler and computed tomography (CT) of the head, cervical spine, chest, abdomen, and pelvis without contrast showed findings of splenic rupture and anoxic brain injury. An extensive workup for traumatic, infectious, coagulopathic, and congenital etiologies was unrevealing, leading to a presumptive diagnosis of spontaneous splenic rupture in a neonate. [ABSTRACT FROM AUTHOR]

The advancement of seat belts have been essential to reducing morbidity and mortality related to motor vehicle collisions (MVCs). The "seat belt sign" (SBS) is an important physical exam finding that has guided management for decades. This study, comprising a systematic review and random-effects meta-analysis, asses the current literature for the likelihood of the SBS relating to intra-abdominal injury and surgical intervention. PubMed and Scopus databases were searched from their beginnings through August 4, 2023 for eligible studies. Outcomes included the prevalence of intra-abdominal injury and need for surgical intervention. Cochrane's Risk of Bias (RoB) tool and the Newcastle-Ottawa Scale (NOS) were applied to assess risk of bias and study quality; Q-statistics and I2 values were used to assess for heterogeneity. The search yielded nine observational studies involving 3050 patients, 1937 (63.5%) of which had a positive SBS. The pooled prevalence of any intra-abdominal injury was 0.42, (95% CI 0.28–0.58, I2 = 96%) The presence of a SBS was significantly associated with increased odds of intra-abdominal injury (OR 3.62, 95% CI 1.12–11.6, P = 0.03; I2 = 89%), and an increased likelihood of surgical intervention (OR 7.34, 95% CI 2.03–26.54, P < 0.001; I2 = 29%). The measurement for any intra-abdominal injury was associated with high heterogeneity, I2 = 89%. This meta-analysis suggests that the presence of a SBS was associated with a statistically significant higher likelihood of intra-abdominal injury and need for surgical intervention. The study had high heterogeneity, likely due to the technological advancements over the course of this study, including seat belt design and diagnostic imaging sensitivity. Further studies with more recent data are needed to confirm these results. [ABSTRACT FROM AUTHOR]

Parallel transmit MRI at 7 T has increasingly been adopted in research projects and provides increased signal‐to‐noise ratios and novel contrasts. However, the interactions of fields in the body need to be carefully considered to ensure safe scanning. Recent advances in physically flexible body coils have allowed for high‐field abdominal imaging, but the effects of increased variability on energy deposition need further exploration. The aim of this study was to assess the impact of subject geometry, respiration phase and coil positioning on the specific absorption rate (SAR). Ten healthy subjects (body mass index [BMI] = 25 ± 5 kg m−2) were scanned (at 3 T) during exhale breath‐hold and images used to generate body models. Seven of these subjects were also scanned during inhale. Simplifications of the coil and body models were first explored, and then finite‐difference time‐domain simulations were run with a typical eight‐channel parallel transmit coil positioned over the abdomen. Simulations were used to generate 10 g averaged SAR (SAR10g) maps across 100,000 phase settings, and the worst‐case scenario 10 g averaged SAR (wocSAR10g) was identified using trigonometric maximisation. The average maximum SAR10g across the 10 subjects with 1 W input power per channel was 1.77 W kg−1. Hotspots were always close to the body surface near the muscle wall boundary. The wocSAR10g across the 10 subjects ranged from 2.3 to 3.2 W kg−1 and was inversely correlated to fat volume percentage (R = 8) and BMI (R = 0.6). The coefficient of variation values in SAR10g due to variations in subject geometry, respiration phase and realistic coil repositioning were 12%, 4% and 12%, respectively. This study found that the variability due to realistic coil repositioning was similar to the variability due to differing healthy subject geometries for abdominal imaging. This is important as it suggests that population‐based modelling is likely to be more useful than individual modelling in setting safe thresholds for abdominal imaging. [ABSTRACT FROM AUTHOR]

A 30-year-old male with hereditary angioedema (HAE) due to C1 inhibitor deficiency was admitted to the Emergency Department (ED) due to severe abdominal pain lasting for 3 hs with severe bloating and weakness. pdC1INH and fluids were applied as usual and the patient was discharged with feeling better. A few hours later abdominal symptoms recurred and erythema appeared, thus the allergy to antispasmodic drug taken by the patient was suspected. In the ED, the patient received anti-allergic treatment and was discharged again. After 3 h severe abdominal symptoms returned with fever. The patient was readmitted to the ED with peritoneal symptoms. Abdominal X-ray confirmed digestive tract perforation. Laparotomy revealed perforation of the chronic duodenal ulcer. In conclusion, we indicate that a HAE patient with an abdominal pain not resolving after usually effective treatment, should be hospitalized and monitored. Differential diagnosis of reasons other than HAE attack should be made. [ABSTRACT FROM AUTHOR]

Rationale and objectives: Aim of this study was to assess the impact of contrast media dose (CMD) reduction on diagnostic quality of photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT). Methods: CT scans of the abdominal region with differing CMD acquired in portal venous phase on a PCD-CT were included and compared to EID-CT scans. Diagnostic quality and contrast intensity were rated. Additionally, readers had to assign the scans to reduced or regular CMD. Regions-of-interest (ROIs) were placed in defined segments of portal vein, inferior vena cava, liver, spleen, kidneys, abdominal aorta and muscular tissue. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Results: Overall 158 CT scans performed on a PCD-CT and 68 examinations on an EID-CT were analyzed. Overall diagnostic quality showed no significant differences for PCD-CT with standard CMD which scored a median 5 (IQR:5-5) and PCD-CT with 70% CMD scoring 5 (4–5). (For PCD-CT, 71.69% of the examinations with reduced CMD were assigned to regular CMD by the readers, for EID-CT 9.09%. Averaged for all measurements SNR for 50% CMD was reduced by 19% in PCD-CT (EID-CT 34%) and CNR by 48% (EID-CT 56%). Virtual monoenergetic images (VMI)50keV for PCD-CT images acquired with 50% CMD showed an increase in SNR by 72% and CNR by 153%. Conclusions: Diagnostic interpretability of PCD-CT examinations with reduction of up to 50% CMD is maintained. PCD-CT deducted scans especially with 70% CMD were often not recognized as CMD reduced scans. Compared to EID-CT less decline in SNR and CNR is observed for CMD reduced PCD-CT images. Employing VMI50keV for CMD-reduced PCD-CT images compensated for the effects.

Introduction: Magnetic resonance elastography (MRE) is a non-invasive method to quantify biomechanical properties of human tissues. It has potential in diagnosis and monitoring of kidney disease, if established in clinical practice. The interplay of flow and volume changes in renal vessels, tubule, urinary collection system and interstitium is complex, but physiological ranges of in vivo viscoelastic properties during fasting and hydration have never been investigated in all gross anatomical segments simultaneously.Method: Ten healthy volunteers underwent two imaging sessions, one following a 12-hour fasting period and the second after a drinking challenge of >10 mL per kg body weight (60–75 min before the second examination). High-resolution renal MRE was performed using a novel driver with rotating eccentric mass placed at the posterior-lateral wall to couple waves (50 Hz) to the kidney. The biomechanical parameters, shear wave speed (cs in m/s), storage modulus (Gd in kPa), loss modulus (Gl in kPa), phase angle (Υ=2πatanGlGd) and attenuation (α in 1/mm) were derived. Accurate separation of gross anatomical segments was applied in post-processing (whole kidney, cortex, medulla, sinus, vessel).Results: High-quality shear waves coupled into all gross anatomical segments of the kidney (mean shear wave displacement: 163 ± 47 μm, mean contamination of second upper harmonics

Eosinophilic appendicitis is a rare inflammatory condition characterized by the infiltration of eosinophils into the appendix, which is often misdiagnosed as acute appendicitis given similarities in their clinical presentation. Acute eosinophilic appendicitis: a rare cause of lower gastrointestinal hemorrhage. Within this particular report, we present a case of eosinophilic appendicitis in a 42-year-old female who underwent a laparoscopic appendectomy. The purpose of this report is to increase awareness about this unique condition and emphasize the importance of considering eosinophilic appendicitis as a differential diagnosis in patients with appendicitis-like symptoms whose clinical examination and laboratory findings may suggest otherwise. [ABSTRACT FROM AUTHOR]

The hook sign is a radiologic finding best appreciated on a sagittal view of the celiac artery with computed tomography (CT) that indicates compression of the celiac artery. It refers to the hooked-shape of the proximal celiac artery caused by extrinsic compression by the median arcuate ligament. When seen in a patient with concurrent abdominal symptoms, it suggests median arcuate ligament syndrome (MALS). We saw the sign in a 15-year-old male via duplex ultrasonography and abdominal CT. He underwent laparoscopic release of the median arcuate ligament and had full resolution of his symptoms at follow-up. • The hook sign describes the hooked-shape of the celiac artery in median arcuate ligament syndrome (MALS). • A sagittal view of the celiac artery on CT during maximal expiration gives the best visualization of the hook sign. • Further workup should be performed whenever the hook sign is identified to characterize the flow through the celiac artery. [ABSTRACT FROM AUTHOR]

Superior mesentery artery (SMA)-like syndrome is an increasingly used term to describe vascular compression of the third duodenal portion between structures other than the superior mesenteric artery and aorta. Although rare, this clinical condition is as serious as true SMA syndrome and requires similar management. However, the diagnostic criteria are not well established yet and require a case-by-case analysis, including a review of various clinical symptoms, especially evolving ones, as well as radiological imaging and effectiveness of conservative therapeutic manoeuvres. The presented case involves a double vascular compression in a 50-year-old woman with no medical history, one of which is between 2 venous structures. The patient had been experiencing recurrent abdominal pain, vomiting, and distension for a long time. Laboratory tests were normal, and gastroesophageal endoscopy revealed Barrett's oesophagus. CT-enterography revealed 2 duodenal vascular compressions. Dietary measures were initiated with close follow-up. To the best of our knowledge, this is the first reported case in the world literature and adds to the existing body of SMA-like syndromes., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology.)

Photon-counting computed tomography (PCCT) has shown promising advancements in abdominal imaging in clinical use. Though more peer-reviewed primary literature is needed, this commentary explores PCCT's potential applications, focusing on enhancing diagnostic accuracy, optimizing radiation dose management, and improving patient care. PCCT offers improved spatial and contrast resolution, lower image noise, and reduced radiation dose. Increased spatial resolution provides better detail in abdominal imaging, aiding in the detection of small lesions and subtle pathological changes. However, this generates more images per scan, raising concerns about "image overload" in PACS, potentially leading to longer reading times and increased stress for radiologists. PCCT's improved contrast resolution enhances tissue differentiation, reducing the need for intravenous contrast agents. The technology's advanced tissue characterization provides several advantages, such as non-invasive and opportunistic liver disease evaluation and improved differentiation of renal and adrenal masses. PCCT's optimized radiation dose management is crucial for patients requiring frequent scans. Enhanced diagnostic accuracy through spectral information aids in tissue differentiation, improving confidence in diagnoses. Streamlined workflows, particularly in emergency settings, and oncologic imaging, are potential benefits, reducing the need for additional imaging studies. Future integration of PCCT into clinical practice requires collaboration, education, and research to fully harness its potential, ensuring optimized abdominal imaging and improved patient care., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Purpose: 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)., Methods: 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., Results: 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., Conclusion: 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., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Gazi University Ethics Committee of Clinical Research issued approval 2019/22. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Yalçın et al.)

• Low-monoenergetic images were preferred for the detection of gallbladder mucosal integrity. • Higher Likert scores for liver enhancement and gallbladder mucosa on low- Kev images associated with positive bile cultures. • Low-Kev liver enhancement and gallbladder mucosal discontinuation were better predictors of superimposed infection. • The strongest predictor variable for bile culture positivity was pericholecystic liver enhancement score. Low mono-energetic CT has been shown to improve visualization of acute abdominal inflammatory processes. We aimed to determine its utility in patients with acute cholecystitis and potential added value in clinical decision making. Sixty-seven consecutive patients with radiological signs of cholecystitis on contrast-enhanced dual-layer CT imaging were retrospectively identified over a four-year period (2/17–8/21). A ranked Likert scale was created for imaging findings present in acute cholecystitis, including gallbladder mucosal integrity and enhancement and pericholecystic liver parenchymal enhancement. These rankings were correlated with laboratory data, followed by sensitivity, specificity, and odds-ratios calculations. Mucosal integrity and pericholecystic liver enhancement were better seen on low-energetic images by unanimous consensus. Presence of pericholecystic liver enhancement and poorer mucosal wall integrity correlated with positive bile cultures (sensitivity: 93.8 % and 96.9 %, specificity: 37.5 and 50.0 %; odds-ratio: 9.0[1.1–68.1 95 %CI] and 31.0 [2.7–350.7 95 %CI], p = 0.017 and p ≤ 0.001) in patients undergoing cholecystostomy (n = 40/67). Moreover, binary regression modeling showed that the strongest predictor variable for bile culture positivity was the score for pericholecystic liver enhancement (Exp(B) = 0.6, P = 0.022). By contrast, other laboratory markers and other imaging findings (such as GB wall thickness) showed lower sensitivities (76–82 %), specificities (16–21 %) and odds ratios (0.2–4.4) for the prediction of infected bile. Pericholecystic liver enhancement and gallbladder wall integrity are better visualized on low-DECT images. These findings also potentially predict bile culture positivity in patients with cholecystitis, which may influence clinical management including the need for intervention. [ABSTRACT FROM AUTHOR]

The extraction of abdominal structures using deep learning has recently experienced a widespread interest in medical image analysis. Automatic abdominal organ and vessel segmentation is highly desirable to guide clinicians in computer-assisted diagnosis, therapy, or surgical planning. Despite a good ability to extract large organs, the capacity of U-Net inspired architectures to automatically delineate smaller structures remains a major issue, especially given the increase in receptive field size as we go deeper into the network. To deal with various abdominal structure sizes while exploiting efficient geometric constraints, we present a novel approach that integrates into deep segmentation shape priors from a semi-overcomplete convolutional auto-encoder (S-OCAE) embedding. Compared to standard convolutional auto-encoders (CAE), it exploits an over-complete branch that projects data onto higher dimensions to better characterize anatomical structures with a small spatial extent. Experiments on abdominal organs and vessel delineation performed on various publicly available datasets highlight the effectiveness of our method compared to state-of-the-art, including U-Net trained without and with shape priors from a traditional CAE. Exploiting a semi-overcomplete convolutional auto-encoder embedding as shape priors improves the ability of deep segmentation models to provide realistic and accurate abdominal structure contours. • A new semi-overcomplete convolutional auto-encoder is proposed to obtain shape priors. • The resulting overcomplete shape priors are integrated into a deep segmentation pipeline. • Experiments focus on abdominal organ and vessel segmentation from public datasets. • Our method outperforms U-Net without/with shape priors from a standard auto-encoder. • A frequency analysis of shape codes is provided in addition to segmentation scores. [ABSTRACT FROM AUTHOR]

This article demonstrates the need for abdominal imaging in COVID-19 patients with systemic symptoms in the differential diagnosis of acute mesenteric ischemia and critical COVID-19 pneumonia. We detail the case of a 91-year-old man, initially diagnosed with severe COVID-19 pneumonia, who was later found to have acute mesenteric ischemia through abdominal CT imaging, despite lacking typical abdominal symptoms. Abdominal CT revealed intramural and portal emphysema, leading to a diagnosis of acute mesenteric ischemia. Given the patient's advanced age and poor condition, supportive care was chosen, with the patient passing away 12 hours post-admission. This case highlights the critical need for comprehensive evaluation, including abdominal imaging, in COVID-19 patients with systemic symptoms to identify other serious conditions like acute mesenteric ischemia, especially in the absence of specific abdominal pain. Early detection is vital for appropriate management and improved patient outcomes., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Nakai et al.)

Purpose: Improving the quality and maintaining the fidelity of large coverage abdominal hyperpolarized (HP) 13 C MRI studies with a patch based global-local higher-order singular value decomposition (GL-HOVSD) spatiotemporal denoising approach., Methods: Denoising performance was first evaluated using the simulated [1- 13 C]pyruvate dynamics at different noise levels to determine optimal k global and k local parameters. The GL-HOSVD spatiotemporal denoising method with the optimized parameters was then applied to two HP [1- 13 C]pyruvate EPI abdominal human cohorts (n = 7 healthy volunteers and n = 8 pancreatic cancer patients)., Results: The parameterization of k global  = 0.2 and k local  = 0.9 denoises abdominal HP data while retaining image fidelity when evaluated by RMSE. The k PX (conversion rate of pyruvate-to-metabolite, X = lactate or alanine) difference was shown to be <20% with respect to ground-truth metabolic conversion rates when there is adequate SNR (SNR AUC  > 5) for downstream metabolites. In both human cohorts, there was a greater than nine-fold gain in peak [1- 13 C]pyruvate, [1- 13 C]lactate, and [1- 13 C]alanine apparent SNR AUC . The improvement in metabolite SNR enabled a more robust quantification of k PL and k PA . After denoising, we observed a 2.1 ± 0.4 and 4.8 ± 2.5-fold increase in the number of voxels reliably fit across abdominal FOVs for k PL and k PA quantification maps., Conclusion: Spatiotemporal denoising greatly improves visualization of low SNR metabolites particularly [1- 13 C]alanine and quantification of [1- 13 C]pyruvate metabolism in large FOV HP 13 C MRI studies of the human abdomen., (© 2024 International Society for Magnetic Resonance in Medicine.)

Metanephric adenoma (MA) is a rare embryonal epithelial tumor that is often diagnosed incidentally. A definitive diagnosis can only be made postoperatively based on the pathological findings. This case report discusses the rare occurrence of a metanephric adenoma, the symptoms it can present with, and the diagnosis, treatment, and immunological staining needed to differentiate metanephric adenoma from other types of renal tumors. In this study, a 37-year-old female presented to the emergency room for vague right lower quadrant pain (RLQ) and underwent imaging that showed a lesion on the lower pole of the left kidney. A subsequent biopsy of the lesion showed a low-grade renal epithelial neoplasm favoring metanephric adenoma. The patient successfully underwent a left partial nephrectomy to remove the tumor, which required no further treatment after resection. Due to the rarity of the tumor, it requires immunohistology to differentiate from other renal tumors such as Wilm's tumor and renal cell carcinoma. This case report aims to recognize proper workup, diagnosis, and treatment to achieve a positive outcome in the setting of this rare tumor., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Szlyk et al.)

Rationale and Objectives: Aim of this study was to assess the impact of contrast media dose (CMD) reduction on diagnostic quality of photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT)., Methods: CT scans of the abdominal region with differing CMD acquired in portal venous phase on a PCD-CT were included and compared to EID-CT scans. Diagnostic quality and contrast intensity were rated. Additionally, readers had to assign the scans to reduced or regular CMD. Regions-of-interest (ROIs) were placed in defined segments of portal vein, inferior vena cava, liver, spleen, kidneys, abdominal aorta and muscular tissue. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated., Results: Overall 158 CT scans performed on a PCD-CT and 68 examinations on an EID-CT were analyzed. Overall diagnostic quality showed no significant differences for PCD-CT with standard CMD which scored a median 5 (IQR:5-5) and PCD-CT with 70% CMD scoring 5 (4-5). (For PCD-CT, 71.69% of the examinations with reduced CMD were assigned to regular CMD by the readers, for EID-CT 9.09%. Averaged for all measurements SNR for 50% CMD was reduced by 19% in PCD-CT (EID-CT 34%) and CNR by 48% (EID-CT 56%). Virtual monoenergetic images (VMI) 50keV for PCD-CT images acquired with 50% CMD showed an increase in SNR by 72% and CNR by 153%., Conclusions: Diagnostic interpretability of PCD-CT examinations with reduction of up to 50% CMD is maintained. PCD-CT deducted scans especially with 70% CMD were often not recognized as CMD reduced scans. Compared to EID-CT less decline in SNR and CNR is observed for CMD reduced PCD-CT images. Employing VMI 50keV for CMD-reduced PCD-CT images compensated for the effects., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yannik Christian Layer reports a relationship with 10.13039/501100004830Siemens Healthcare AG that includes: funding grants., (© 2024 The Authors.)

Intestinal obstruction without a past surgical history of abdominal surgeries or trauma is a rare and challenging clinical situation. This case report describes the presentation, diagnosis, and management of intestinal obstruction in a patient with an uncommon aetiology of small bowel obstruction. A 62-year-old female with a past medical history of hypertension, diabetes, and atrial fibrillation presented to the Emergency Department with symptoms of vomiting and abdominal distension for two days. The absence of similar prior episodes and lack of surgical or trauma history were notable. Physical examination revealed a mildly distended, tympanic abdomen. Radiographic X-ray and CT imaging identified dilated small bowel loops due to a mechanical small bowel obstruction without any evident aetiology. Surgical intervention involved the release of the incarcerated bowel loops and repair of the omental breach causing the small bowel obstruction, leading to a smooth postoperative recovery. This case of intestinal obstruction, caused by an incarcerated bowel through an omental breach in a patient with no history of abdominal surgery or trauma, underscores the diagnostic challenges in atypical presentations. The critical role of imaging, specifically abdominal X-ray and CT scan, was key in identifying the rare obstruction cause. The successful surgical release and repair of the incarcerated bowel highlight the need for tailored surgical approaches. This report emphasizes the importance of considering uncommon etiologies and demonstrates the complexities involved in the diagnosis and treatment of gastrointestinal conditions, advocating for a multidisciplinary approach. The importance of considering rare etiologies in patients with abdominal pain, especially those lacking a typical history, is emphasized. The effective use of imaging and tailored surgical approach was key to the successful outcome. This report adds to the limited literature on omental breaches causing intestinal obstruction and underlines the necessity of a multidisciplinary approach in such cases. • This atypical presentation underscores the importance of considering a broad differential diagnosis in patients with abdominal symptoms, even in the absence of common predisposing factors. • This highlights the crucial role of comprehensive imaging in diagnosing complex abdominal conditions. • This successful outcome demonstrates the effectiveness of surgical intervention for rare causes of intestinal obstruction and the importance of a tailored surgical approach based on the specific anatomical findings in each case. [ABSTRACT FROM AUTHOR]