Comparative assessment of the capability of machine learning-based radiomic models for predicting omental metastasis in locally advanced gastric cancer.

The study aims to investigate the predictive capability of machine learning algorithms for omental metastasis in locally advanced gastric cancer (LAGC) and to compare the performance metrics of various machine learning predictive models. A retrospective collection of 478 pathologically confirmed LAGC patients was undertaken, encompassing both clinical features and arterial phase computed tomography images. Radiomic features were extracted using 3D Slicer software. Clinical and radiomic features were further filtered through lasso regression. Selected clinical and radiomic features were used to construct omental metastasis predictive models using support vector machine (SVM), decision tree (DT), random forest (RF), K-nearest neighbors (KNN), and logistic regression (LR). The models' performance metrics included accuracy, area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In the training cohort, the RF predictive model surpassed LR, SVM, DT, and KNN in terms of accuracy, AUC, sensitivity, specificity, PPV, and NPV. Compared to the other four predictive models, the RF model significantly improved PPV. In the test cohort, all five machine learning predictive models exhibited lower PPVs. The DT model demonstrated the most significant variation in performance metrics relative to the other models, with a sensitivity of 0.231 and specificity of 0.990. The LR-based predictive model had the lowest PPV at 0.210, compared to the other four models. In the external validation cohort, the performance metrics of the predictive models were generally consistent with those in the test cohort. The LR-based model for predicting omental metastasis exhibited a lower PPV. Among the machine learning algorithms, the RF predictive model demonstrated higher accuracy and improved PPV relative to LR, SVM, KNN, and DT models.

Omental Hernia as a Potential Cause of False-Positive GI Bleeding on 99m Tc-RBC Scintigraphy.

ABSTRACT: Gastrointestinal bleeding scintigraphy is a noninvasive study used to determine the presence of active bleeding, localize the bleeding site, and estimate the bleeding volume for prognostic purposes in patients with suspected gastrointestinal bleeding. However, it is important to note that false-positive results can occur due to various reasons. In this case, we present the scenario of a middle-aged woman who exhibited symptoms of gastrointestinal bleeding and underwent 99m Tc-RBC scintigraphy. The imaging revealed an accumulation of radiotracer in the hypogastric region, which was later determined to be caused by an omental hernia on SPECT/CT images. The herniated structure caused congestion in the mesenteric vessels, leading to the accumulation of 99m Tc-RBC. This case highlights the significance of considering anatomical anomalies and nonbleeding pathologies when interpreting the 99m Tc-RBC scintigraphy results for gastrointestinal bleeding.

Computed tomography of a canine omental torsion secondary to a chronic abdominal gossypiboma and concurrent incidental broad ligament torsion.

A 5-year-old female spayed Dogue de Bordeaux was referred for concerns of an abdominal mass and peritoneal effusion. Abdominal radiographs identified a mid-ventral abdominal soft tissue opaque mass containing a radiopaque marker consistent with a gossypiboma. Contrast-enhanced abdominal CT identified two whirl signs associated with the abdominal gossypiboma. Exploratory laparotomy confirmed an omental torsion with encapsulated gossypiboma and concurrent incidental torsion of the remnant of the right broad ligament. Based on a literature review, omental torsions are an unreported complication of gossypibomas in canids.

Ruptured primary omental ectopic pregnancy during the first trimester.

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Inguinal hernia leading to omental torsion: Role of CT in differentiating from other clinical mimics - a case report and literature review.

Omental torsion is a very rare cause of acute abdomen. Clinically, it mimics other common pathologies such as acute appendicitis, acute diverticulitis and acute cholecystitis. It is therefore no surprise, that it was rarely diagnosed pre operatively before the advent and easy availability of modern imaging techniques. CT scan, in particular, can diagnose omental torsion with confidence pre operatively. This can make conservative treatment possible in cases of primary omental torsion and guide regarding the appropriate treatment in cases of secondary torsion. We present a case of a young male patient who presented to Emergency department with symptoms of acute abdomen. Clinical and laboratory findings were non-specific for any specific cause of acute abdomen. CT scan, however, showed omental fat stranding with whirlpool sign representing omental torsion which was seen to be secondary to left inguinal hernia. Patient was operated in emergency and necrotic omentum was resected and hernia repaired. Post-operative recovery was uneventful.

Omental lipoma in pediatric age group: clinical presentation, image findings and management

ABSTRACT A 2-year-old female patient, admitted in the emergency room, presented diarrhea for 5 days and bloody stools in the last 24 hours. Physical examination revealed no significant findings. Ultrasound was initially performed, showing an elongated, well delimited and solid mass occupying since right hypocondrium until left iliac fossa, displacing adjacent structures. In sequence, magnetic resonance imaging was performed for confirmation of findings suggestive of omentum lipoma. After 1 week, the surgical resection was performed by videolaparoscopic acess. During 2-year follow-up, there was no sign of recurrence.

Reporte de Caso Clínico: Linfangioma quístico de epiplón / Case Report: Cystic lymphangioma of the omentum

INTRODUCCIÓN: El linfangioma mesentérico es un tumor quístico congénito, benigno y raro de los vasos linfáticos, que se presenta en menos del 5% de los casos a nivel abdominal. Se presentan con mayor frecuencia durante la infancia. Esta patología se debe considerar como diagnóstico diferencial de abdomen agudo y masas abdominales pediátricas. CASO CLÍNICO: Niño de 6 años de edad, presentó cuadro de dolor abdominal y peritonismo. Presentó febrícula, signo de rebote positivo, además leucocitosis y neutrofilia. Ecografía evidenció abundante líquido libre en abdomen y pelvis. EVOLUCIÓN: Se realizó laparotomía exploratoria, con hallazgo de masa quística dependiente de epiplón mayor, la misma que se resecó. La histopatología fue negativa para malignidad y compatible con linfangioma quístico, la inmunohistoquímica con marcador D2-40 positi-vo. El paciente evolucionó favorablemente sin complicaciones quirúrgicas y sin evidencia de recurrencia hasta el año de seguimiento. CONCLUSION: El linfangioma quístico mesentérico puede debutar con sintomatología de abdomen agudo, puede también tener una evolución crónica. La resección completa es el tratamiento de elección, actualmente se realizan procedimientos mínimamente invasivos, con resultados favorables. La ecografía es útil para realizar un seguimiento a largo plazo.(AU)

BACKGROUND: Mesenteric lymphangioma is a rare, benign congenital cystic tumor of the lym-phatic vessels, which occurs in less than 5% pf the cases at the abdomen. They appear most often during childhood. This tumor should be considered as a differential diagnosis of acute abdomen and other abdominal masses. CASE REPORT: A 6-year-old boy presented with abdominal pain and peritonism. He presented a low-grade fever, a positive rebound sign, as well as leukocytosis and neutrophilia. Ultrasono-graphy showed abundant free fluid in abdomen and pelvis. EVOLUTION: Exploratory laparotomy was performed, finding a cystic mass dependent on the greater omentum, this mass was resected. Histopathology was negative for malignancy and compatible with cystic lymphangioma, immunohistochemistry was positive for D2-40 marker. The patient evolved favorably without surgical complications and without evidence of recurrence up to one year of follow-up. CONCLUSION: Mesenteric cystic lymphangioma can present with symptoms of acute abdomen, it can also have a chronic evolution. Complete resection is the treatment of choice, currently minimally invasive procedures are performed with favorable results. Ultrasound is useful for long-term follow-up.(AU)

Disfunción del catéter de diálisis peritoneal por atrapamiento de la trompa de Falopio / Disfunction of peritoneal dialysis catheter caused by Fallopian tube entrapment

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Pseudotumor of the Omentum Associated with Migration of the Ingested Crab-Leg

Foreign body ingestion is not uncommon in clinical practice, and it may occasionally lead to penetration injuries. Emergency physicians and radiologists sometimes fail to obtain complete histories including ingestion and may overlook the possibility of foreign body-induced complications. Herein, we report a case of stomach antrum perforation due to foreign body migration. We were unaware of the patient's history of eating the Korean delicacy "Kanjang-gaejang," which is raw crab seasoned with soy sauce. Several imaging diagnostic modalities had suggested the possibility of a malignant mass in the gastrocolic ligament area. During the operation, a crab leg was discovered as the cause of an intra-abdominal abscess. The patient underwent an antrectomy, a vagotomay, and a transverse colon wedge resection. We present this unusual case of a pseudotumorous lesion caused by ingestion of Kanjang-gaejang.

Infarto de apéndice epiploico e infarto segmentario de epiplón mayor / Epiploic appendagitis and omental infarction: diagnostic imaging findings

El infarto de apéndice epiploico y el infarto segmentario del epiplón mayor son las dos causas infrecuentes de abdomen agudo no quirúrgicos, que suelen simular otras patologías quirúrgicas, como diverticulitis, apendicitis o colecistitis. Ambos presentan similar clínica, pronóstico y tratamiento. Entre noviembre de 1998 y agosto de 2001, se diagnosticaron 10 casos de infarto de apéndice epiploico y 6 de infarto segmentario del epiplón mayor mediante US, con confirmación posterior mediante TC de 6 infartos de apéndice epiploico y los 6 infartos segmentarios del epiplón mayor. Un paciente presentó una asociación de púrpura de Sch÷enlein-Henoch con infarto segmentario del epiplón mayor. Todos fueron tratados en forma conservadora. El US y la TC permiten un correcto diagnóstico, evitando así cirugías innecesarias. El propósito del presente trabajo es describir las características clínicas, ecográficas y tomográficas y correlacionar éstos resultados con la bibliografía (AU)