RAMA-WeRA Risk Score in Predicting the Ruptured Appendicitis in Emergency Department; a Multicenter Study for External Validation.

Introduction: Distinguishing between ruptured and non-ruptured acute appendicitis presents a significant challenge. This study aimed to validate the accuracy of RAMA-WeRA Risk Score in predicting ruptured appendicitis (RA) in emergency department. Methods: This study was a multicenter diagnostic accuracy study conducted across six hospitals in Thailand from February 1, 2022, to January 20, 2023. The eligibility criteria included individuals aged >15 years suspected of acute appendicitis, presenting to the ED, and having an available pathology report following appendectomy or intraoperative diagnosis by the surgeon. We assessed the screening performance characteristics of RAMA-WeRA Risk Score, in detecting the ruptured appendicitis (RA) cases. Results: 860 patients met the study criteria. 168 (19.38%) had RA and 692 (80.62%) patients had non-RA. The area under the receiver operating characteristic curve (AuROC) of RAMA-WeRA Risk Score was 75.11% (95% CI: 71.10, 79.11). The RAMA-WeRA Risk Score > 6 points (high-risk group) demonstrated a positive likelihood ratio (LR) of 3.22 in detecting the ruptured cases. The sensitivity and specificity of score in > 6 cutoff point was 43.8% (95%CI: 36.2, 51.6) and 86.4% (95%CI: 83.6, 88.9), respectively. Conclusions: The RAMA-WeRA Risk Score can predict rupture in patients presenting with suspected acute appendicitis in the emergency department with total accuracy of 75% for high-risk cases.

Managing the Open Abdomen: Selecting an Appropriate Treatment Strategy.

Significance: The laparotomy is a common surgical procedure with a wide range of indications. Ideally, once the goals of surgery were achieved, the incision edges could then be approximated and the abdomen primarily closed. However, in some circumstances, it may be impossible to achieve primary closure, and instead the abdomen is intentionally left open. This review discusses the indications and objectives for the open abdomen (OA), summarizes the most common techniques for temporary abdominal closure, and illustrates treatment algorithms grounded in the current recommendations from specialty experts. Recent Advances: Still a relatively young technique, multiple strategies, and technologies have emerged to manage the OA. So too have the recommendations evolved, based on updated classifications that take wound characteristics into account. Recent studies have also brought greater clarity on recommendations for managing infection and malnutrition to support improved clinical outcomes. Critical Issues: The status of the OA can change rapidly depending on the patient's condition, the wound quality, and many other factors. Thus, there is a significant need for comprehensive treatment strategies that can be adapted to these developing circumstances. Future Directions: Treatment recommendations should be continuously updated as new technologies are introduced and old techniques fall out of use.

Primary Omentum Malignant Hemangiopericytoma Present with Acute Abdomen.

The greater omentum primary malignant tumors are rare, with less than 50 cases reported. Malignant hemangiopericytomas constitute only four of these cases. The common clinical manifestations of a malignant omental tumor are abdominal mass and pain. We report on a woman 38 years old who came to the hospital's emergency department with a finding consisting of intestinal obstruction (abdominal pain, constipation, abdominal distention, and vomiting), and during a clinical examination a mass was discovered in the lower half of her abdomen. She had been experiencing these symptoms for three days before her arrival. During a clinical examination, a large size, hard mobile mass was discovered in the lower half of her abdomen. The patient underwent an abdominal CT scan which indicated the presence of a sizable, soft tissue mass located within the abdominal and pelvic region, exerting pressure on the small bowel loops, with mild free ascites. Due to the patient's acute abdomen, an exploration laparotomy was performed, revealing a large mass in the omentum measuring 20×20×10 cm and weighing 3 kg. The mass, along with the omentum, was completely removed, and histopathology confirmed a malignant hemangiopericytoma.

Primary omental infarction - a benign cause of acute abdomen.

Objectives: Omental infarction (OI) is an uncommon cause of acute abdominal pain. A high index of clinical suspicion is required for diagnosis of OI as the incidence is less than 1 %, presenting with abdominal pain. We report primary OI's clinical and radiological profile from a single tertiary care hospital in India. Methods: In this retrospective cross-sectional study, the electronic medical and radiology records of patients with abdominal pain were reviewed over seven years (2015-2022). Variables were systematically collected and analyzed. Results: A total of 22 patients diagnosed with primary OI were included in this study. Male preponderance (63.6 %) was noted with a mean age of 47.45 years (SD ± 13.84; range: 18-72 years). Most patients belonged to class I obesity (according to the Asia-Pacific body mass index classification) with a mean BMI of 26.56 kg/m2 (SD ± 3.21 kg/m2). All patients had abdominal pain as the primary symptom, with a mean duration of 8.64 days (SD ± 10.15; range: 1-42 days). The most common locations of pain were the right hypochondrium (27.3 %) and diffuse (27.3 %), followed by the right iliac fossa (18.1 %). Most (95.45 %, n=21/22) patients were treated conservatively, and only one required surgical intervention. Conclusions: Primary OI is a rare and benign cause of acute abdomen. Obesity is a risk factor but does not correlate with the size or severity of OI. Radiological imaging, like a computed tomography (CT) scan, is essential for diagnosis. A conservative management line should be the first approach in treating primary OI before considering surgical options.

Critical considerations for the management of acute abdomen in transplant patients.

The number of solid organ transplantations performed annually is increasing and are increasing in the following order: Kidney, liver, heart, lung, pancreas, small bowel, and uterine transplants. However, the outcomes of transplants are improving (organ survival > 90% after the 1st year). Therefore, there is a high probability that a general surgeon will be faced with the management of a transplant patient with acute abdomen. Surgical problems in immunocompromised patients may not only include graft-related problems but also nongraft-related problems. The perioperative regulation of immunosuppression, the treatment of accompanying problems of immunosuppression, the administration of cortisol and, above all, the realization of a rapidly deteriorating situation and the accurate evaluation and interpretation of clinical manifestations are particularly important in these patients. The perioperative assessment and preparation includes evaluation of the patient's cardiovascular system and determining if the patient has hypertension or suppression of the hypothalamic-pituitary-adrenal axis, or if the patient has had any coagulation mechanism abnormalities or thromboembolic episodes. Immunosuppression in transplant patients is associated with the use of calcineurin inhibitors, corticosteroids, and antiproliferation agents. Many times, the clinical picture is atypical, resulting in delays in diagnosis and treatment and leading to increased morbidity and mortality. Multidetector computed tomography is of utmost importance for early diagnosis and management. Transplant recipients are prone to infections, especially specific infections caused by cytomegalovirus and Clostridium difficile, and they are predisposed to intraoperative or postoperative complications that require great care and vigilance. It is necessary to follow evidence-based therapeutic protocols. Thus, it is required that the clinician choose the correct therapeutic plan for the patient (conservative, emergency open surgery or minimally invasive surgery, including laparoscopic or even robotic surgery).

Acute abdomen secondary to ovarian tumour incarcerated in an umbilical hernia: A case report.

Acute abdomen due to incarcerated umbilical hernia is a surgical emergency. Acute abdomen secondary to gynaecological conditions is not uncommon. However, acute abdomen due to incarceration of a gynaecological tumour in an umbilical hernia is rare. A 25-year-old nullipara was admitted to the accident and emergency unit with a history of recurrent lower abdominal pain and abdominal swelling for 4 weeks. Pain worsened within the last 24 h necessitating presentation. Examination revealed a low-grade pyrexia, tachypnoea, an umbilical swelling with generalised abdominal tenderness, and a pelvic mass more in the right iliac fossa. Bedside abdomino-pelvic ultrasound scan confirmed bilateral adnexal masses with features suggestive of mature teratoma. A diagnosis of acute abdomen secondary to ovarian tumour accident was made. An emergency exploratory laparotomy revealed a huge right ovarian tumour incarcerated in an umbilical hernia. She had bilateral ovarian cystectomy and herniorrhaphy. Gynaecological tumours presenting as incarcerated or strangulated hernias are extremely rare but can be a cause of acute abdomen in women.

Surgical outcome of pediatric abdominal trauma at Tertiary Hospital, Northwest Ethiopia, a 3-year retrospective study.

INTRODUCTION: Abdominal trauma in children is a significant health concern that often leads to severe complications and even death. Children experience trauma more frequently than adults, with approximately one in four pediatric patients suffering from serious abdominal injuries. Falls are the leading cause of such trauma among children, which is intriguing considering that most hospital admissions for pediatric abdominal injuries result from blunt force impacts. METHOD: A retrospective cross-sectional analysis of medical records was conducted to examine all patients under the age of 16 who underwent exploratory laparotomy for abdominal trauma between January 1, 2020, and January 1, 2023. The clinical data were gathered using a data extraction sheet from each patient's medical charts. Information on socio-demographic characteristics, injury mechanisms, clinical conditions at the initial presentation, intraoperative findings and complications, and patient outcomes were collected. RESULTS: The study involved a total of 90 patients, consisting of 72 males (80%) and 18 females (20%). The average age of the patients was 10, with a standard deviation of 4.7, ranging from 2 to 16 years. Half of the patients were below the age of 10, accounting for 46 individuals (51%). The causes of the injuries varied among patients below and above the age of 10. However, overall, bullet injuries were the most common cause, accounting for 28 cases (31%), followed by falls in 21 cases (23.3%), horse or donkey kicks in 10 cases (11.1%), stab injuries in 10 cases (11.1%), horn injuries in 7 cases (7.8%), and road traffic accidents in 6 cases (6.7%). Physical assault, blasts, and other types of injuries, such as hen bites and metal rod injuries, were observed in 8 cases (8.9%) of the patients. Fall accidents, horse or donkey kicks, and horn injuries were particularly more common among children below the age of 10, while bullet injuries and stab injuries were most common among those above the age of 10. CONCLUSION: Following abdominal trauma in children, a range of complications may arise, including immediate issues such as infections and hemorrhaging, as well as long-term consequences like impaired organ functionality and psychological distress. In our region, young children are particularly vulnerable to accidents involving falls, kicks from horses or donkeys, and injuries caused by horns. Therefore, it is crucial to educate parents about these hazards. Additionally, providing appropriate guidance on firearm safety is essential for individuals who possess such weapons.

Quantitative 23Na magnetic resonance imaging in the abdomen at 3 T.

OBJECTIVES: To assess the feasibility of sodium-23 MRI for performing quantitative and non-invasive measurements of total sodium concentration (TSC) and relaxation in a variety of abdominal organs. MATERIALS AND METHODS: Proton and sodium imaging of the abdomen was performed in 19 healthy volunteers using a 3D cones sequence and a sodium-tuned 4-rung transmit/receive body coil on a clinical 3 T system. The effects of B1 non-uniformity on TSC measurements were corrected using the double-angle method. The long-component of 23Na T2* relaxation time was measured using a series of variable echo-times. RESULTS: The mean and standard deviation of TSC and long-component 23Na T2* values were calculated across the healthy volunteer group in the kidneys, cerebrospinal fluid (CSF), liver, gallbladder, spleen, aorta, and inferior vena cava. DISCUSSION: Mean TSC values in the kidneys, liver, and spleen were similar to those reported using 23Na-MRI previously in the literature. Measurements in the CSF and gallbladder were lower, potentially due to the reduced spatial resolution achievable in a clinically acceptable scan time. Mean long-component 23Na T2* values were consistent with previous reports from the kidneys and CSF. Intra-population standard error was larger in smaller, fluid-filled structures due to fluid motion and partial volume effects.

ACR Appropriateness Criteria® Sepsis.

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. A search for the underlying cause of infection typically includes radiological imaging as part of this investigation. This document focuses on thoracic and abdominopelvic causes of sepsis. In 2017, the global incidence of sepsis was estimated to be 48.9 million cases, with 11 million sepsis-related deaths (accounting for nearly 20% of all global deaths); therefore, understanding which imaging modalities and types of studies are acceptable or not acceptable is imperative. The 5 variants provided include the most commonly encountered scenarios in the setting of sepsis along with recommendations and data for each imaging study. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Comparison of Clinical, Pathological, and Procedural Characteristics of Adult and Pediatric Acute Appendicitis before and during the COVID-19 Pandemic.

BACKGROUND: This study aims to analyze the impact of the COVID-19 pandemic on the clinical, pathological, and surgical characteristics of acute appendicitis (AA) at the University Hospital Centre (UHC) Zagreb. METHODS: This retrospective study analyzed demographic, clinical, and surgical data from consecutive AA patients. Data were collected from an electronic database for two periods: 1 January to 31 December 2019 (pre-COVID-19), and 11 March 2020, to 11 March 2021 (COVID-19 pandemic). RESULTS: During the two study periods, 855 appendectomies were performed, 427 in the pre-pandemic, and 428 during the pandemic. Demographic data were comparable between groups. There was statistically no significant difference in the type of appendectomy (p = 0.33) and the median hospital length of stay (3; (2-5) days, p = 0.08). There was an increase in the conversion rate during the pandemic period (4.2% vs. 7.7%, p = 0.03). The negative appendectomy rate and the incidence of perforated AA did not differ significantly (p = 0.34 for both). CONCLUSIONS: We did not observe a significant increase in the rate of AA complications during the COVID-19 pandemic at the UHC Zagreb. This may be attributed to two factors: (1) AA was diagnosed and treated as an emergency, which remained available during the pandemic, and (2) diagnostic and therapeutic protocols remained unaltered. We recommend a laparoscopic approach even during the COVID-19 pandemic.

Rupture of Mycotic Abdominal Aortic Aneurysm as a Result of Incompletely Treated Multiple Peripheral Mycotic Aneurysms.

Background: A mycotic aortic aneurysm is a rare type of aortic aneurysm that can have disastrous outcomes. Most mycotic aneurysms originate from infectious sources, such as trauma, vegetation in the heart, and adjacent infectious sources. If a mycotic aneurysm is diagnosed, it should be treated simultaneously with the primary source of the infection. Case Summary: Treatment was performed for a mycotic aneurysm of the brachial artery that occurred suddenly during treatment for a fever for which the primary source of infection had not been confirmed. The workup revealed that a mycotic aneurysm of the brachial artery was the cause of the fever, followed by aneurysms in the abdomen and lower extremities and even vegetation in the heart that was not initially present. The patient declined to undergo treatment for personal reasons. After 5 months, it was revealed that the abdominal aortic aneurysm, which was initially considered normal aorta, was ruptured; however, the aneurysm was successfully treated. Conclusions: A peripheral mycotic aneurysm may be associated with multiple aneurysms. Appropriate diagnosis and complete treatments are necessary to prevent fatal consequences.

Observation Safely Reduces the Use of the Computerized Tomography in Medium-to-Low-Risk Patients with Suspected Acute Appendicitis: Results of a Randomized Controlled Trial.

Objectives-The objective was to compare the effectiveness of observation in standard-of-care computed tomography (CT) in adult patients with suspected acute appendicitis (AA). Methods-Patients with clinically suspected AA and inconclusive diagnosis after primary clinical examination, laboratory examination, and transabdominal ultrasound (TUS) were eligible for the study, and they were randomized (1:1) to parallel groups: observation-group patients were observed for 8-12 h and then, repeated clinical and laboratory examinations and TUS were performed; CT group (control group) patients underwent abdominopelvic CT scan. The study utilized Statistical Analysis System 9.2 for data analysis, including tests, logistic regression, ROC analysis, and significance evaluation. Patients were enrolled in the study at Vilnius University Hospital Santaros Klinikos in Lithuania between December 2018 and June 2021. Results-A total of 160 patients (59 men, 101 women), with a mean age of 33.7 ± 14.71, were included, with 80 patients in each group. Observation resulted in a reduced likelihood of a CT scan compared with the CT group (36.3% vs. 100% p < 0.05). One diagnostic laparoscopy was performed in the observation group; there were no cases of negative appendectomy (NA) in the CT group. Both conditional CT and observation pathways resulted in high sensitivity and specificity (97.7% and 94.6% vs. 96.7% and 95.8%). Conclusions-Observation including the repeated evaluation of laboratory results and TUS significantly reduces the number of CT scans without increasing NA numbers or the number of complicated cases.

A Rare Case of Primary Posterior Abdominal Wall Muscle Hydatid Cyst With Thoracolumbar Spinal Extension.

Primary intramuscular hydatid cysts are uncommon due to the contractile nature of muscles and their lactic acid content. Hydatid cysts with spinal extension are sometimes seen with primary vertebral body involvement. Our patient presented with a slow-growing posterior abdominal wall mass, and upon magnetic resonance imaging (MRI), it was revealed to be several cystic lesions in the abdomen wall with extension through the neural foramina into the spinal canal. The key differentials for spinal canal masses with neural foraminal expansion and muscle involvement are peripheral nerve sheath tumors. Our case report adds hydatid cysts to the differentials for well-defined cysts with variable intensities on MRI.

Biomechanical properties of the human superficial fascia: Site-specific variability and anisotropy of abdominal and thoracic regions.

Superficial fascia is a fibrofatty tissue found throughout the body. Initially described in relation to hernias, it has only recently received attention from the scientific community due to new evidence on its role in force transmission and structural integrity of the body. Considering initial difficulties in its anatomical identification, to date, a characterization of the superficial fascia through mechanical tests is still lacking. The mechanical properties of human superficial fasciae of abdominal and thoracic districts (back) of different subjects (n = 4) were then investigated, focusing on anisotropy and viscoelasticity. Experimental tests were performed on samples taken in two perpendicular directions according to body planes (cranio-caudal and latero-medial axes). Data collected from two different uniaxial tensile protocols, failure (i.e., ultimate tensile strength and strain at break, Young's modulus and toughness) and stress-relaxation (i.e., residual stress), were processed and then grouped for statistical analysis. Failure tests confirmed tissue anisotropy, revealing the stiffer nature of the latero-medial direction compared to the cranio-caudal one, for both the districts (with a ratio of the respective Young's moduli close to 2). Furthermore, the thoracic region exhibited significantly greater strength and resultant Young's modulus compared to the abdomen (with greater results along the latero-medial direction, such as 6.13 ± 3.11 MPa versus 0.85 ± 0.39 MPa and 24.87 ± 15.23 MPa versus 3.19 ± 1.62 MPa, respectively). On the contrary, both regions displayed similar strain at break (varying between 38 and 47%), with no clear dependence from the loading directions. Stress-relaxation tests highlighted the viscous behavior of the superficial fascia, with no significant differences in the stress decay between directions and districts (35-38% of residual stress after 300 s). All these collected results represent the starting point for a more in-depth knowledge of the mechanical characterization of the superficial fascia, which can have direct implications in the design, implementation, and effectiveness of site-specific treatments.

Introducing AEM-RADS: A novel reporting and data system for abdominal emergencies.

PURPOSE: The Reporting and Data System (RADS) has proven successful in various medical settings, but a standardized reporting system for abdominal emergencies is lacking. In this study, the Abdominal Emergency Reporting and Data System (AEM-RADS) for urgent findings on abdominal CT scans is introduced to address the need for consistency in emergency radiology. METHODS: In this prospective observational study, conducted over a six-month period, the urgency of abdominal CT scans was assessed using the proposed AEM-RADS scoring system. The committee developed a scale ranging from AEM-RADS 1 (normal) to AEM-RADS 5 (urgent disease). Interobserver agreement between two observers with different experience was evaluated, and robust AEM-RADS reference values were established by radiologists who were not observers. Statistical analysis used mean, standard deviations and Kendall's tau analysis for interobserver agreement. RESULTS: Among 2656 patients who underwent CT for abdominal emergencies, the AEM-RADS distribution was 17.50% AEM-RADS 1, 28.57% AEM-RADS 2, 7.22% AEM-RADS 3, 35.61% AEM-RADS 4, and 11.06% AEM-RADS 5. Interobserver agreement was high, especially for urgent and emergent cases (p < 0.0001). Notable discrepancies were observed in AEM-RADS categories 2C-D and 3B-C, emphasizing the influence of radiologists' experience on interpretation. However, the interobserver agreement for both AEM-RADS 2C-D and 3B-C were statistically significant (p < 0.001). CONCLUSIONS: AEM-RADS showed promising reliability, particularly in identifying urgent and emergent cases. Despite some inter-observer discrepancies, the system showed potential for standardized emergency workups. AEM-RADS could significantly enhance diagnostic accuracy in abdominal emergencies and provide a structured framework for shared decision-making between clinicians and radiologists.0.

Hughes Abdomen Closure Technique Versus Continuous Closure in Emergency Midline Laparotomy: A Randomized Controlled Study.

Background Abdominal wound dehiscence, a serious postoperative issue, remains a significant concern for surgeons due to its potential to increase patient mortality and morbidity. Disruption can occur at any point after surgery, sparking debate over the optimal closure method for midline vertical abdominal wounds. Therefore, it's crucial to determine the safest approach. Our randomized clinical trial is planned to compare the risk of a burst abdomen associated with the Hughes abdominal closure technique to that of continuous abdominal closure. Methods All patients >18 years scheduled for emergency midline laparotomy were randomly assigned into two groups using computer-generated random numbers: Group A underwent Hughes repair (12 patients) and Group B underwent continuous closure (17 patients). Preoperative data, including patient demographics, and postoperative outcomes, such as time for rectus closure, wound dehiscence, surgical site infection (SSI), and length of hospital stay, were documented for analysis. Results The study found that the average patient age was 37.89 years, with more males than females. Both groups had an equal distribution of co-morbidities (p = 0.468), but none of these factors were statistically significant. Burst abdomen occurred in 25% of group A and 41.1% of group B (p = 0.367, not significant). Incisional hernia was absent in both groups. Surgical site infection (p = 0.119) and respiratory complications (p = 0.16) were not statistically significant between groups. However, in group A, the regressive analysis showed significant associations between burst abdomen, surgical site infection (p = 0.018), and respiratory complications (p = 0.007), while in group B, these associations were not significant (p = 0.252 for SSI and p = 0.906 for respiratory complications). Conclusion The occurrence of burst abdomen and closure time differences between continuous and Hughes techniques were not significant. The Hughes technique was quicker to learn (32 vs. 22 minutes). Burst abdomen was more common in continuous closure (group A: 25% vs. group B: 41%), favoring the Hughes technique. Factors like age, gender, and others didn't significantly impact the burst abdomen in either group.

The key to success in blocking lateral cutaneous branches with re-modified thoracoabdominal nerves block through perichondrial approach: a newly discovered space between the endothoracic fascia, diaphragm, and costodiaphragmatic recess.

PURPOSE: This study aimed to determine whether the administration of a modified thoracoabdominal nerves block through perichondrial approach (M-TAPA) could result in the blockade of the lateral cutaneous branches. This study focused on a newly discovered anatomical space/plane adjacent to the M-TAPA plane, which we termed "space between the endothoracic fascia, diaphragm, and costodiaphragmatic recess: SEDIC." METHODS: Thirteen sides of nine formalin-embalmed cadavers were macroscopically dissected to investigate the anatomical spaces related to the effects of M-TAPA. Furthermore, ten adult volunteers were administered 20 mL of 0.2% ropivacaine into the abdominal plane (corresponding to the M-TAPA plane) and the SEDIC, and a pinprick test was performed 1 h after the injection. RESULTS: Cadaver macrodissection revealed the presence of the SEDIC adjacent to the M-TAPA plane. The SEDIC was completely spatially isolated from the M-TAPA plane by the presence of costal cartilage and/or tendinous structures. In the volunteer study, the administration of local anesthetics into the SEDIC effectively blocked the lateral cutaneous branches of T8-T12, in addition to the anterior branches. CONCLUSION: Our study revealed the presence of the SEDIC adjacent to the M-TAPA plane. Administration of local anesthetics into the SEDIC, named re-modified TAPA, may have the potential to enhance the analgesic effect in the abdominal region.

Deep learning image reconstruction generates thinner slice iodine maps with improved image quality to increase diagnostic acceptance and lesion conspicuity: a prospective study on abdominal dual-energy CT.

BACKGROUND: To assess the improvement of image quality and diagnostic acceptance of thinner slice iodine maps enabled by deep learning image reconstruction (DLIR) in abdominal dual-energy CT (DECT). METHODS: This study prospectively included 104 participants with 136 lesions. Four series of iodine maps were generated based on portal-venous scans of contrast-enhanced abdominal DECT: 5-mm and 1.25-mm using adaptive statistical iterative reconstruction-V (Asir-V) with 50% blending (AV-50), and 1.25-mm using DLIR with medium (DLIR-M), and high strength (DLIR-H). The iodine concentrations (IC) and their standard deviations of nine anatomical sites were measured, and the corresponding coefficient of variations (CV) were calculated. Noise-power-spectrum (NPS) and edge-rise-slope (ERS) were measured. Five radiologists rated image quality in terms of image noise, contrast, sharpness, texture, and small structure visibility, and evaluated overall diagnostic acceptability of images and lesion conspicuity. RESULTS: The four reconstructions maintained the IC values unchanged in nine anatomical sites (all p > 0.999). Compared to 1.25-mm AV-50, 1.25-mm DLIR-M and DLIR-H significantly reduced CV values (all p < 0.001) and presented lower noise and noise peak (both p < 0.001). Compared to 5-mm AV-50, 1.25-mm images had higher ERS (all p < 0.001). The difference of the peak and average spatial frequency among the four reconstructions was relatively small but statistically significant (both p < 0.001). The 1.25-mm DLIR-M images were rated higher than the 5-mm and 1.25-mm AV-50 images for diagnostic acceptability and lesion conspicuity (all P < 0.001). CONCLUSIONS: DLIR may facilitate the thinner slice thickness iodine maps in abdominal DECT for improvement of image quality, diagnostic acceptability, and lesion conspicuity.

Towards more precise automatic analysis: a systematic review of deep learning-based multi-organ segmentation.

Accurate segmentation of multiple organs in the head, neck, chest, and abdomen from medical images is an essential step in computer-aided diagnosis, surgical navigation, and radiation therapy. In the past few years, with a data-driven feature extraction approach and end-to-end training, automatic deep learning-based multi-organ segmentation methods have far outperformed traditional methods and become a new research topic. This review systematically summarizes the latest research in this field. We searched Google Scholar for papers published from January 1, 2016 to December 31, 2023, using keywords "multi-organ segmentation" and "deep learning", resulting in 327 papers. We followed the PRISMA guidelines for paper selection, and 195 studies were deemed to be within the scope of this review. We summarized the two main aspects involved in multi-organ segmentation: datasets and methods. Regarding datasets, we provided an overview of existing public datasets and conducted an in-depth analysis. Concerning methods, we categorized existing approaches into three major classes: fully supervised, weakly supervised and semi-supervised, based on whether they require complete label information. We summarized the achievements of these methods in terms of segmentation accuracy. In the discussion and conclusion section, we outlined and summarized the current trends in multi-organ segmentation.