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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]

Efficient abdominal coverage with T1‐mapping methods currently available in the clinic is limited by the breath hold period (BHP) and the time needed for T1 recovery. This work develops a T1‐mapping framework for efficient abdominal coverage based on rapid T1 recovery curve (T1RC) sampling, slice‐selective inversion, optimized slice interleaving, and a convolutional neural network (CNN)‐based T1 estimation. The effect of reducing the T1RC sampling was evaluated by comparing T1 estimates from T1RC ranging from 0.63 to 2.0 s with reference T1 values obtained from T1RC = 2.5–5 s. Slice interleaving methodologies were evaluated by comparing the T1 variation in abdominal organs across slices. The repeatability of the proposed framework was demonstrated by performing acquisition on test subjects across imaging sessions. Analysis of in vivo data based on retrospectively shortening the T1RC showed that with the CNN framework, a T1RC = 0.84 s yielded T1 estimates without significant changes in mean T1 (p > 0.05) or significant increase in T1 variability (p > 0.48) compared to the reference. Prospectively acquired data using T1RC = 0.84 s, an optimized slice interleaving scheme, and the CNN framework enabled 21 slices in a 20 s BHP. Analyses across abdominal organs produced T1 values within 2% of the reference. Repeatability experiments yielded Pearson's correlation, repeatability coefficient, and coefficient of variation of 0.99, 2.5%, and 0.12%, respectively. The proposed T1 mapping framework provides full abdominal coverage within a single BHP. [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.

BackgroundEndometriomas are a type of ovarian cyst composed of degenerated blood products from hemorrhage of ectopic endometrial tissue. Endometriomas can rupture, causing hemoperitoneum, and present with signs and symptoms similar to other, more common abdominal emergencies. Therefore, they are not often diagnosed preoperatively. Ultrasound and cross-sectional imaging can assist in diagnosis of endometriomas. We present a case of ruptured endometrioma causing massive hemoperitoneum that was initially suspected to represent malignancy with carcinomatosis.Case presentationA 32-year-old Hispanic woman presented with sharp abdominal pain and 15-pound unintentional weight loss over 6 months. Laboratory work was significant for a negative pregnancy test and elevated cancer antigen-125. Computed tomography of the abdomen and pelvis demonstrated a 13-cm complex cystic mass in the left adnexa with moderate hyperdense ascites and omental nodularity. Ultrasound demonstrated a large left adnexal complex cystic structure with internal echoes, and chest computed tomography showed no signs of intrathoracic neoplastic or infectious processes. Her presentation was concerning for malignancy with carcinomatosis. Fluid from a paracentesis was sent for culture and cytology. Diagnostic laparoscopy revealed that the left ovary had been completely replaced by an endometrioma, which had a small ruptured area superiorly. Brown deposits of endometriosis were present on the cyst, omentum, and various peritoneal linings. Tissue samples of the endometrium, myometrium, cervix, ovaries, fallopian tubes, peritoneum, omentum, and paracolic spaces were taken and showed no hyperplastic, dysplastic, or malignant cells on pathology.ConclusionsRuptured endometrioma and ruptured hemorrhagic cyst should be included in the differential diagnosis when a premenopausal female presents with hemoperitoneum in combination with complex adnexal cystic masses in the absence of trauma. Cancer antigen-125 and cancer antigen 19-9 can be falsely elevated in the setting of ruptured endometrioma.

Transabdominal ultrasound is a promising imaging modality for pancreatic cystic lesions. This study aims to determine if transabdominal ultrasonography with CT fusion (TAUS-f) using volume navigation can be used to measure pancreatic cystic lesions (PCLs) compared to CT alone. We evaluated 33 patients prospectively with known PCLs. The readers evaluated each PCL’s size and imaging characteristics on TAUS-f and CT alone. These were compared to endoscopic ultrasonography reports. A total of 43 PCLs from 32 patients were evaluated. The detection rate by TAUS-f was 93%. Two of the three undetected PCLs were in the tail of the pancreas. Inter-reader variabilities for TAUS-f and CT were 0.005 cm and 0.03 cm, respectively. Subgroup analysis by size and location demonstrated that inter-modality variability between TAUS-f and CT was smallest for lesions < 1.5 cm with a size difference of −0.13 cm for each reader and smallest in the pancreatic head with a size difference of −0.16 cm and −0.17 cm for readers 1 and 2. We found that TAUS-f effectively evaluates PCLs compared to CT alone, thus suggesting that it should be considered part of the surveillance algorithm for a subset of patients.

Malignant melanoma is a highly aggressive disease with a propensity for metastatic spread. Although recent advances in targeted therapies have improved outcomes, effective screening for metastasis remains an important area of further research. We present a case of a man in his 70s who was recently diagnosed with recurrent, locally advanced melanoma. He presented with abdominal fullness, jaundice, and poor appetite. MR imaging of the abdomen revealed innumerable hepatic cysts with internal fluid-fluid levels which were markedly increased in size and number from recent imaging. These findings necessitated a broad differential that included parasitic or bacterial infection, metastases, or drug-induced polycystic liver disease. Subsequent biopsy revealed metastatic melanoma consistent with the patient's primary tumor. The patient was ultimately transitioned to comfort care measures due to the burden of the liver metastases and passed away shortly after presentation.

BackgroundPneumatosis cystoides intestinalis is a rare and usually benign condition in which multiple thin-walled cysts develop in the submucosa or subserosa of the gastrointestinal tract. While usually asymptomatic, severe cases can result in pneumoperitoneum, which can be managed surgically or medically depending on circumstances. We present a case of a patient with pneumatosis cystoides intestinalis, which presented as pneumoperitoneum following trauma. To our knowledge, there are no other published cases in which a trauma patient with pneumoperitoneum was found to have radiologic evidence of pneumatosis cystoides intestinalis.Case presentationWe present the case of a 37-year-old Hispanic male admitted to the hospital after being involved in a motorcycle accident. Computed tomography imaging of the abdomen and pelvis with oral and intravenous contrast demonstrated trace pneumoperitoneum, possibly originating from the splenic flexure of the colon without evidence of extravasation of oral contrast. Laparoscopy with conversion to exploratory laparotomy revealed bowel abnormalities at the distal transverse colon and splenic flexure, which were identified as pneumatosis cystoides intestinalis by pathology. There was no evidence of bowel perforation. A panel of abdominal radiologists attended the computed tomography interpretation to note that incidental atraumatic or traumatic rupture of the cysts could have caused the pneumoperitoneum. The patient had an uncomplicated postoperative course and was transferred to another facility per insurance request.ConclusionsWhen presenting in the context of trauma, pneumatosis cystoides intestinalis can lead to difficult management decisions. To our knowledge, there are no existing evidence-based guidelines for the scenario of concurrent pneumatosis cystoides intestinalis, blunt abdominal trauma, and pneumoperitoneum in a patient with a benign abdominal exam. This patient's pneumoperitoneum was likely caused by rupture of preexisting cysts rather than frank bowel perforation. Patients who are asymptomatic, lack signs of clinically worrisome disease, and have a low pretest probability will likely not benefit from surgery and can be medically managed. Thorough discussion between surgeons and radiologists can be helpful when evaluating the clinical significance of a patient's pneumatosis cystoides intestinalis and aid in the decision to perform surgery.

Radiologists in training draw from their early experiences in residency when choosing a fellowship. Once they have decided on an abdominal imaging fellowship, applicants must learn to navigate the interview process. During this challenging time, applicants explore the difference in clinical curricula and rotations, meet potential mentors and clinical faculty, consider potential academic interests and projects, and choose what location they would like to train for one year after residency. When in training, fellows undergo the challenge of finding employment while learning new skills and refining their abilities to become a well-rounded radiologist and clinician. This article summarizes key points potential applicants should consider when deciding on an abdominal imaging fellowship, how to prepare for the interview season, and how to plan their fellowship year before fellows take the next step to becoming attendings.

Photoacoustic (PA) imaging has been extensively investigated in application in biomedicine over the last decade. This article reviews the motivation, significance, and system configuration of a few ongoing studies of implementing photoacoustic technology in musculoskeletal imaging, abdominal imaging, and interstitial sensing. The review then summarizes the methodologies and latest progress of relevant projects. Finally, we discuss our expectations for the future of translation research in PA imaging.

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

Artificial intelligence (AI) has been a topic of substantial interest for radiologists in recent years. Although many of the first clinical applications were in the neuro, cardiothoracic, and breast imaging subspecialties, the number of investigated and real-world applications of body imaging has been increasing, with more than 30 FDA-approved algorithms now available for applications in the abdomen and pelvis. In this manuscript, we explore some of the fundamentals of artificial intelligence and machine learning, review major functions that AI algorithms may perform, introduce current and potential future applications of AI in abdominal imaging, provide a basic understanding of the pathways by which AI algorithms can receive FDA approval, and explore some of the challenges with the implementation of AI in clinical practice. [ABSTRACT FROM AUTHOR]

Transabdominal ultrasound is a promising imaging modality for pancreatic cystic lesions. This study aims to determine if transabdominal ultrasonography with CT fusion (TAUS-f) using volume navigation can be used to measure pancreatic cystic lesions (PCLs) compared to CT alone. We evaluated 33 patients prospectively with known PCLs. The readers evaluated each PCL's size and imaging characteristics on TAUS-f and CT alone. These were compared to endoscopic ultrasonography reports. A total of 43 PCLs from 32 patients were evaluated. The detection rate by TAUS-f was 93%. Two of the three undetected PCLs were in the tail of the pancreas. Inter-reader variabilities for TAUS-f and CT were 0.005 cm and 0.03 cm, respectively. Subgroup analysis by size and location demonstrated that inter-modality variability between TAUS-f and CT was smallest for lesions < 1.5 cm with a size difference of −0.13 cm for each reader and smallest in the pancreatic head with a size difference of −0.16 cm and −0.17 cm for readers 1 and 2. We found that TAUS-f effectively evaluates PCLs compared to CT alone, thus suggesting that it should be considered part of the surveillance algorithm for a subset of patients. [ABSTRACT FROM AUTHOR]

We present the clinical case of a 53-year-old woman referred for suspicion of recurrence of a mesonephric-like adenocarcinoma of the ovary. Abdominal and pelvic CT revealed multiple round/oval solid nodules with similar density scattered throughout the abdomen and pelvis, the biggest ones appearing in the left hypochondrium; no normal-appearing spleen or ascites were observed. These radiological findings and the absence of significant elevation of CA 125 levels made the radiologists hypothesize that these aspects were related to abdominal splenosis. They asked the patient about previous medical history of splenic injury, which she confirmed, referring it was a consequence of a remote major trauma. A 99mTc-labeled heat-denatured erythrocytes (99mTc-DRBC) scintigraphy/ hybrid SPECT/CT was then performed for definitive diagnosis; it showed spleen remnants as foci of increased radiopharmaceutical uptake in the same locations as the nodules appearing in the CT. This diagnostic work-up was consistent with abdominal splenosis, mimicking peritoneal carcinomatosis of ovarian cancer.

Photoacoustic (PA) imaging has been extensively investigated in application in biomedicine over the last decade. This article reviews the motivation, significance, and system configuration of a few ongoing studies of implementing photoacoustic technology in musculoskeletal imaging, abdominal imaging, and interstitial sensing. The review then summarizes the methodologies and latest progress of relevant projects. Finally, we discuss our expectations for the future of translation research in PA imaging. [ABSTRACT FROM AUTHOR]

We present a case of a large pancreatic pseudocyst in a 69-year-old man following post biopsy pancreatitis. Radiological findings revealed a thick-walled, fluid filled mass in proximity to the pancreas. Although pancreatic pseudocysts generally self-resolve, extensive or complicated cysts may require surgical or interventional management. Pseudocyst size >6 cm, compression of the inferior vena cava or biliary duct, and severe symptoms often prognosticate the need for intervention.

(1) Background: Currently, multisystem inflammatory syndrome in children (MIS-C) is diagnosed based on clinical symptoms and laboratory findings of inflammation in the body. Once MIS-C is diagnosed, children will need to be followed over time. The imaging modalities most commonly used in the evaluation of patients with MIS-C include radiographs, ultrasound (US), and computed tomography (CT). Our study aims to summarise the literature data for the main gastrointestinal and pulmonary imaging features in children diagnosed with MIS-C and to share a single-centre experience. (2) Methods: We present the imaging findings in a cohort of 51 children diagnosed with MIS-C, admitted between December 2020 and February 2022. Imaging studies include chest and abdominal radiographs, thoracic, abdominal, and neck US and echocardiography (ECHO), and CT of the chest, abdomen, and pelvis. (3) Results: In accordance with the results in other studies, our observations show predominantly gastrointestinal involvement (GI) with ascites (33/51, 65%) and lymphadenopathy (19/51, 37%), ileitis or colitis (18/51, 35%), some cases of splenomegaly (9/51, 18%), hepatomegaly (8/51, 16%), and a few cases of renal enlargement (3/51, 6%) and gallbladder fossa oedema/wall thickening (2/51, 4%). Most common among the thoracic findings are posterior–basal consolidations (16/51, 31%), pleural effusion (14/51, 27%), and ground-glass opacities (12/51, 24%). We also register the significant involvement of the cardiovascular system with pericarditis (30/51, 58%), pericardial effusion (16/51, 31%), and myocarditis (6/51, 12%). (4) Conclusions: Radiologists should be aware of those imaging findings in order to take an important and active role not only in applying an accurate diagnosis, but also in the subsequent management of children with MIS-C. Radiological findings are not the primary diagnostic tool, but can assist in the evaluation of the affected systems and guide treatment.

Abstract Background Recently, a whole-body 5 T MRI scanner was developed to open the door of abdominal imaging at high-field strength. This prospective study aimed to evaluate the feasibility of renal imaging at 5 T and compare the image quality, potential artifacts, and contrast ratios with 3 T. Methods Forty healthy volunteers underwent MRI examination both at 3 T and 5 T. MRI sequences included T1-weighted gradient-echo (GRE), T2-weighted fast spin echo, diffusion-weighted imaging, and multi-echo GRE T2* mapping. Image quality and presence of artifacts were assessed for all sequences using four-point scales. For anatomical imaging, the signal-to-noise ratio (SNR) and contrast ratio (CR) of abdomen organ tissues were calculated. Besides, for functional imaging, the contrast-to-noise ratio of cortex/medulla was calculated. Wilcoxon signed rank-sum test was used to compare the visual evaluation scores and quantitative measurements between 3 and 5 T images. Results Compared to 3 T examination, T1-weighted sequence at 5 T showed significantly better image quality with higher conspicuity of the renal veins and arteries, and comparable artifacts. Image quality was comparable between both field strengths on T2-weighted images, whereas a significantly higher level of artifacts was observed at 5 T. Besides, 5 T MRI contributed to higher SNR and CR for abdomen organ tissues. For functional imaging, 5 T MRI showed improved corticomedullar discrimination. There was no significant difference between apparent diffusion coefficient of renal at 3 T and 5 T, while 5 T MRI resulted in significantly shorter T2* values in both cortex and medulla. Conclusions 5 T MRI provides anatomical and functional images of the kidney with sufficient image quality.

In 2017, our tertiary hospital-based imaging practice transitioned from score-based peer review to the peer learning methodology for learning and improvement. In our subspecialized practice, peer learning submissions are reviewed by domain experts, who then provide feedback to individual radiologists, curate cases for group learning sessions, and develop associated improvement initiatives. In this paper, we share lessons learned from our abdominal imaging peer learning submissions with the assumption that trends in our practice likely mimic others', and hope that other practices can avoid future errors and elevate the level of the quality of their own performance. Adoption of a nonjudgmental and efficient method to share peer "learning opportunities" and "great calls" has increased participation in this activity and increased transparency into our practice, thus allowing for visualization of trends in performance. Peer learning allows us to bring our own individual knowledge and practices together for group review in a collegial and safe environment. We learn from each other and decide how to improve together. [ABSTRACT FROM AUTHOR]

Since its first observation in the 18th century, the diffusion phenomenon has been actively studied by many researchers. Diffusion-weighted imaging (DWI) is a technique to probe the diffusion of water molecules and create a MR image with contrast based on the local diffusion properties. The DWI pixel intensity is modulated by the hindrance the diffusing water molecules experience. This hindrance is caused by structures in the tissue and reflects the state of the tissue. This characteristic makes DWI a unique and effective tool to gain more insight into the tissue's pathophysiological condition. In the past decades, DWI has made dramatic technical progress, leading to greater acceptance in clinical practice. In the abdominal region, however, acquiring DWI with good quality is challenging because of several reasons, such as large imaging volume, respiratory and other types of motion, and difficulty in achieving homogeneous fat suppression. In this review, we discuss technical advancements from the past decades that help mitigate these problems common in abdominal imaging. We describe the use of scan acceleration techniques such as parallel imaging and compressed sensing to reduce image distortion in echo planar imaging. Then we compare techniques developed to mitigate issues due to respiratory motion, such as free-breathing, respiratory-triggering, and navigator-based approaches. Commonly used fat suppression techniques are also introduced, and their effectiveness is discussed. Additionally, the influence of the abovementioned techniques on image quality is demonstrated. Finally, we discuss the current and future clinical applications of abdominal DWI, such as whole-body DWI, simultaneous multiple-slice excitation, intravoxel incoherent motion, and the use of artificial intelligence. Abdominal DWI has the potential to develop further in the future, thanks to scan acceleration and image quality improvement driven by technological advancements. The accumulation of clinical proof will further drive clinical acceptance. [ABSTRACT FROM AUTHOR]

Objective: To develop a logistic regression model that combines clinical and radiological parameters for prediction of complicated appendicitis. Methods: 248 patients with histologically proven uncomplicated (n = 214) and complicated (n = 34) acute appendicitis were analyzed retrospectively. All patients had undergone a presurgical abdominal and/or pelvic computed tomography (CT) scan, assessed by two radiologists. A model using univariate and multivariate logistic regression analyses was developed, and the strength of association between independent predictors and complicated acute appendicitis was evaluated by adjusted odds radio. Clinical parameters were gender, age, anorexia, vomiting, duration of symptoms, right lower abdominal quadrant (RLQ) tenderness, rebound tenderness, body temperature, white blood cell (WBC) count, and neutrophil ratio. Radiological parameters were appendix diameter, appendicolith, caecal wall thickening, mesenteric lymphadenopathy, extraluminal air, abscess, fat stranding, and periappendicular fluid. Results: Four features (body temperature＞37.2 °C, vomiting, appendicolith, and periappendiceal fluid) were included in the logistic regression model, and yielded an area under the curve (AUC) of 0.87 (95% confidence interval (CI), 0.80–0.93), sensitive of 88%, and specificity of 74%. Conclusion: The logistic regression model makes an accurate and simple prediction of complicated appendicitis possible.

Encapsulating peritoneal sclerosis (EPS) is a rare, but sometimes fatal, complication of peritoneal dialysis characterized by diffuse thickening and encapsulation of the bowel and peritoneum. In more advanced cases, the peritoneum will gradually calcify. EPS usually presents as partial small bowel obstruction and diagnosed on imaging studies. We present a case of a 19-year-old female on long-term peritoneal dialysis with EPS and diffuse peritoneal calcifications.

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]

Objectives: This study investigated the feasibility and image quality of ultra-low-dose unenhanced abdominal CT using photon-counting detector technology and tin prefiltration. Materials and Methods: Employing a first-generation photon-counting CT scanner, eight cadaveric specimens were examined both with tin prefiltration (Sn 100 kVp) and polychromatic (120 kVp) scan protocols matched for radiation dose at three different levels: standard-dose (3 mGy), low-dose (1 mGy) and ultra-low-dose (0.5 mGy). Image quality was evaluated quantitatively by means of contrast-to-noise-ratios (CNR) with regions of interest placed in the renal cortex and subcutaneous fat. Additionally, three independent radiologists performed subjective evaluation of image quality. The intraclass correlation coefficient was calculated as a measure of interrater reliability. Results: Irrespective of scan mode, CNR in the renal cortex decreased with lower radiation dose. Despite similar mean energy of the applied x-ray spectrum, CNR was superior for Sn 100 kVp over 120 kVp at standard-dose (17.75 ± 3.51 vs. 14.13 ± 4.02), low-dose (13.99 ± 2.6 vs. 10.68 ± 2.17) and ultra-low-dose levels (8.88 ± 2.01 vs. 11.06 ± 1.74) (all p ≤ 0.05). Subjective image quality was highest for both standard-dose protocols (score 5; interquartile range 5–5). While no difference was ascertained between Sn 100 kVp and 120 kVp examinations at standard and low-dose levels, the subjective image quality of tin-filtered scans was superior to 120 kVp with ultra-low radiation dose (p < 0.05). An intraclass correlation coefficient of 0.844 (95% confidence interval 0.763–0.906; p < 0.001) indicated good interrater reliability. Conclusions: Photon-counting detector CT permits excellent image quality in unenhanced abdominal CT with very low radiation dose. Employment of tin prefiltration at 100 kVp instead of polychromatic imaging at 120 kVp increases the image quality even further in the ultra-low-dose range of 0.5 mGy. [ABSTRACT FROM AUTHOR]

Purpose: Knowledge of kidney stone composition can help in patient management; urine composition analysis and dual-energy CT are frequently used to assess stone type. We assessed if threshold-based stone segmentation and radiomics can determine the composition of kidney stones from single-energy, non-contrast abdomen–pelvis CT. Methods: With IRB approval, we identified 218 consecutive patients (mean age 64 ± 13 years; male:female 138:80) with the presence of kidney stones on non-contrast, abdomen–pelvis CT and surgical or biochemical proof of their stone composition. CT examinations were performed on one of the seven multidetector-row scanners from four vendors (GE, Philips, Siemens, Toshiba). Deidentified CT images were processed with a radiomics prototype (Frontier, Siemens Healthineers) to segment the entire kidney volumes with an AI-based organ segmentation tool. We applied a threshold of 130 HU to isolate stones in the segmented kidneys and to estimate radiomics over the segmented stone volume. A coinvestigator verified kidney stone segmentation and adjusted the volume of interest to include the entire stone volume when necessary. We applied multiple logistic regression tests with precision recall plots to obtain area under the curve (AUC) using a built-in R statistical program. Results: The threshold-based stone segmentation successfully isolated kidney stones (uric acid: n = 102 patients, calcium oxalate/phosphate: n = 116 patients) in all patients. Radiomics differentiated between calcium and uric acid stones with an AUC of 0.78 (p < 0.01, 95% CI 0.73–0.83), 0.79 sensitivity, and 0.90 specificity regardless of CT vendors (GE CT: AUC = 0.82, p < 0.01, 95% CI 0.740–0896; Siemens CT: AUC = 0.77, 95% CI 0.700–0.846, p < 0.01). Conclusion: Automated threshold-based stone segmentation and radiomics can differentiate between calcium oxalate/phosphate and urate stones from non-contrast, single-energy abdomen CT. [ABSTRACT FROM AUTHOR]

• Prevalence of APCT within the adolescent blunt trauma population was found to be 59.3% (95% CI 54.2%-64.9%). • Of the patients who received APCT, 123 (37.9%) had positive findings on APCT with 65 (20.0%) having intraabdominal injury. • Of patients who received APCT 25 (7.7%) had injury that required abdominal surgery. • 100% of patients with intraabdominal injury had at least one clinical predictor for intraabdominal injury while 28.7% of patients without intraabdominal injury who received APCT lacked any key predictors. • Abnormal abdominal exam, positive chest x-ray, positive or indeterminate FAST, elevated AST and elevated ALT were independently associated with intraabdominal injury. The algorithm for evaluating adolescent patients with blunt trauma includes abdominal pelvic CT (APCT). The aim of this study is to evaluate the utility of APCT in this context. We performed a retrospective review of adolescent (11 to 18 years of age) blunt trauma patients at an urban adult level 1 trauma center from January 2015 to December 2019. The primary outcome was the prevalence of positive findings on APCT scan. Additionally, clinical risk factors concerning for intra-abdominal injury were analyzed. There were 546 patients evaluated for blunt trauma and the prevalence of APCT within the population was 59.3% (95% CI 54.2%-64.9%). Of the patients who received APCT, 123 (37.9%) had positive findings on APCT. Only 25 patients (7.7% of those who underwent APCT) required abdominal surgery while 40 patients (12.3%) had intraabdominal injury that did not require surgery. Risk factors were present in 100% of patients with intraabdominal injury and absent in 28.7% of patients without intraabdominal injury. Abnormal abdominal exam, abnormal FAST, positive chest x-ray and elevated transaminases were independently associated with intraabdominal injury. Our study found that adolescent blunt trauma patients treated at our trauma center had a higher rate of APCT usage, but a comparable rate of positive findings when compared with the most recent literature. Future studies should focus on reducing the number of patients who undergo APCT despite an absence of clinical risk factors. [ABSTRACT FROM AUTHOR]

(1) Background: Currently, multisystem inflammatory syndrome in children (MIS-C) is diagnosed based on clinical symptoms and laboratory findings of inflammation in the body. Once MIS-C is diagnosed, children will need to be followed over time. The imaging modalities most commonly used in the evaluation of patients with MIS-C include radiographs, ultrasound (US), and computed tomography (CT). Our study aims to summarise the literature data for the main gastrointestinal and pulmonary imaging features in children diagnosed with MIS-C and to share a single-centre experience. (2) Methods: We present the imaging findings in a cohort of 51 children diagnosed with MIS-C, admitted between December 2020 and February 2022. Imaging studies include chest and abdominal radiographs, thoracic, abdominal, and neck US and echocardiography (ECHO), and CT of the chest, abdomen, and pelvis. (3) Results: In accordance with the results in other studies, our observations show predominantly gastrointestinal involvement (GI) with ascites (33/51,65%) and lymphadenopathy (19/51,37%), ileitis or colitis (18/51,35%), some cases of splenomegaly (9/51,18%), hepatomegaly (8/51,16%), and a few cases of renal enlargement (3/51, 6%) and gallbladder fossa oedema/wall thickening (2/51, 4%). Most common among the thoracic findings are posterior-basal consolidations (16/51, 31%), pleural effusion (14/51, 27%), and ground-glass opacities (12/51, 24%). We also register the significant involvement of the cardiovascular system with pericarditis (30/51, 58%), pericardial effusion (16/51, 31%), and myocarditis (6/51,12%). (4) Conclusions: Radiologists should be aware of those imaging findings in order to take an important and active role not only in applying an accurate diagnosis, but also in the subsequent management of children with MIS-C. Radiological findings are not the primary diagnostic tool, but can assist in the evaluation of the affected systems and guide treatment. [ABSTRACT FROM AUTHOR]

A 17-year-old female presented to our hospital complaining of bloody diarrhea 4-6 times per day for the past month. She was a known case of inflammatory bowel disease noncompliant to her medications. Abdominal computed tomography revealed an unusually dilated mass in the retroperitoneum at L2 vertebral level connecting the lumbar and left renal veins. The renal artery was visualized separately, and a diagnosis of communicating vein varicosity was made. This lesion can be misleading on imaging, hence our aim to disseminate our findings to practicing radiologists. The differential diagnosis of these lesions include retroperitoneal lymphadenopathy, renal artery aneurysms, and testicular cancers causing retroperitoneal lymphadenopathy. To our knowledge, this is the first case to be reported in association with inflammatory bowel disease, perhaps providing a novel insight into the pathogenesis of this lesion that has not been considered in the contemporary literature.

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]

Artificial intelligence (AI) has been a topic of substantial interest for radiologists in recent years. Although many of the first clinical applications were in the neuro, cardiothoracic, and breast imaging subspecialties, the number of investigated and real-world applications of body imaging has been increasing, with more than 30 FDA-approved algorithms now available for applications in the abdomen and pelvis. In this manuscript, we explore some of the fundamentals of artificial intelligence and machine learning, review major functions that AI algorithms may perform, introduce current and potential future applications of AI in abdominal imaging, provide a basic understanding of the pathways by which AI algorithms can receive FDA approval, and explore some of the challenges with the implementation of AI in clinical practice.

The case of a 26-year-old male patient with perforation of Meckels diverticulum, a rare complication of the most common congenital anomaly of the gastrointestinal tract, is reported in this article. This congenital condition can remain asymptomatic for a long time, and it can get complicated with diverticulitis, enteroliths, neoplasms, and rarely perforation, as in this case. A preoperative radiological assessment is of fundamental importance for proper diagnostic and therapeutic management of the patient. In this article, we present the typical tomographic imaging features of this infrequent complication to assist radiologists in detecting it.