Role of Computed Tomography in Blunt Abdominal Trauma

Introduction: Blunt abdominal trauma is one of the commonly encountered surgical emergencies. The diagnostic modality that helps in optimum management of these patients includes chest and abdominal x-rays, Focused Assessment Sonography for Trauma scan and Computed Tomography. In selected hemodynamically stable patients who are candidates for non-operative management, Contrast Enhanced Computed Tomography is not considered essential and hence avoiding its own radiation hazards and decreasing extra financial burden to the patients. Aims: To evaluate whether Contrast Enhanced Computed Tomography is necessary or not in case of blunt trauma abdomen. Methods: This is a hospital based prospective study done in the department of surgery at Nepalgunj Medical College, Kohalpur conducted from October 2020 to March 2021. The patients with blunt abdominal trauma who were hemodynamically stable at the time of presentation and those who became stable after resuscitation were included. These patient’s detailed history was taken, clinical examination done. Focused Assessment Sonography for Trauma scan was done at the time of presentation along with chest x-ray and other necessary blood investigation. Data were analyzed with Statistical Package for Social Sciences version 25 and p-value <0.05 was taken as significant. Results: Out of total 53 patients, age group between 11-20 and 21-30 years comprising of 13 patients with male: female ratio of 1.94:1 were affected more. Fall injury, being the most common mode, comprised 20 patients. The commonest organ involved was spleen seen in 17 patients (32.1%), liver in 16 patients (30.2%). In 44 (83.0%) patients, Computed Tomography scan was done only in nine patients who were also managed conservatively, except one who underwent laparoscopic evacuation of collected blood. Seventeen (32.1%) patients underwent repeat ultrasonography without any new findings. Conclusion: Patients with blunt abdominal trauma with stable hemodynamics can be managed conservatively with limited use of Contrast Enhanced Computed Tomography scan.

Creation of synthetic contrast-enhanced computed tomography images using deep neural networks to screen for renal cell carcinoma

Objectives: To elucidate if synthetic contrast enhanced computed tomography (CECT) images created from plain CT images using deep neural networks (DNN) could be used for screening, clinical diagnosis, and postoperative follow up of small diameter renal tumors by comparing the concordance rate between real and synthetic CECT images and the diagnoses according to 10 urologists. Methods: This retrospective, multicenter study included 155 patients (artificial intelligence training cohort [n=99], validation cohort [n=56]) who underwent surgery for small-diameter (≤40 mm) renal tumors, with the pathological diagnosis of renal cell carcinoma, during 2010 to 2020. Preoperatively, dynamic plain CT and CECT images were obtained. We created a learned DNN using pix2pix. We examined the quality of the synthetic CECT images created using this DNN and compared them with real CECT images using the zero mean normalized cross correlation parameter. We assessed concordance rates between real and synthetic images and diagnoses according to 10 urologists by creating a receiver operating characteristic curve and calculating the area under the curve (AUC). Results: The synthetic CECT images were highly concordant with the real CECT images, regardless of the existence or morphology of the renal tumor. Regarding the concordance rate, a greater AUC was obtained with synthetic CECT (AUC=0.892) than with only CT (AUC=0.720; p<0.001). Conclusions: This study is the first to use DNN to create a high-quality synthetic CECT image that was highly concordant with a real CECT image. Synthetic CECT images could be used for urological diagnoses and clinical screening.

Rare Case of Gastric Schwannoma Simulating Gastrointestinal Stromal Tumour-A Case Report

Gastric schwannoma (GS) is a rare, benign, slow-growing neoplasm representing 0.2% of all gastric tumors. We report a rare case of Gastric schwannoma in a 56 year old woman who presented with abdominal discomfort and vomiting since few years. Contrast enhanced Computed Tomography showed a well-defined homogeneously attenuating lesion with homogenous enhancement. Wedge gastrectomy was done with a possible diagnosis of Gastrointestinal stromal tumor, but was confirmed to have Gastric schwannoma on histopathology showing spindle cells with peripheral cuff of lymphoid aggregates and S-100 protein positivity on immunohistochemistry. Gastric schwannoma should be included in the differential diagnosis of a gastric intramural or exophytic mass when Computed Tomography shows a well-defined homogeneously attenuating lesion with progressively increasing homogenous enhancement without hemorrhage, necrosis, and degeneration.

Misdiagnosis of Rectus Abdominis Abscess Owing to Delayed Contrast-Enhanced Computed Tomography

A 77-year-old man, who was on anticoagulation, presented with a painful lump on the right abdominal wall. Laboratory tests showed slight anaemia and elevated inflammatory markers. Abdominal plain computed tomography (CT) revealed a mass in the right rectus abdominis muscle. He was admitted with a diagnosis of primary rectus abdominis haematoma. However, on the next day, the diagnosis was corrected to primary rectus abdominis abscess, following contrast-enhanced CT of the abdomen. This case illustrates the importance of considering primary rectus abdominis abscess in patients with suspected primary rectus abdominis haematoma, and contrast should be used when performing CT.