Contrast-enhanced Computed Tomography Scan Research Articles

Radiomic features at Contrast-enhanced CT Predict Virus-driven Liver Fibrosis: A Multi-institutional Study.

Liver fibrosis is a major cause of morbidity and mortality among in chronic hepatitis patients. Radiomics, particularly of the spleen, may improve diagnostic accuracy and treatment strategies. External validations are necessary to ensure reliability and generalizability. In this retrospective study, we developed three radiomics models using contrast-enhanced CT scans from 167 patients with liver fibrosis (training group) between January 2020 and December 2021. Radiomic features were extracted from arterial venous, portal venous, and equilibrium phase images. Recursive feature selection random forest (RFS-RF) and the least absolute shrinkage and selection operator (LASSO) logistic regression were used for feature selection and dimensionality reduction. Performance was assessed by area under the curve, C-index, calibration plots and decision curve analysis. External validation was performed on 114 patients from two institutions. Twenty-five radiomic features were significantly associated with fibrosis stage, with 80% of the top 10 features originating from portal venous phase spleen images. The radiomics models showed good performance in the validation cohort (C-indices: 0.723-0.808) and excellent calibration. Decision curve analysis indicated clinical benefits, with machine learning-based radiomics models (RFR-score and SVMR-score) providing more significant advantages. Radiomic features offer significant benefits over existing serum indices for staging virus-driven liver fibrosis, underscoring the value of radiomics in enhancing diagnostic accuracy. Specifically, radiomics analysis of the spleen presents additional noninvasive options for assessing fibrosis, highlighting its potential in improving patient management and outcomes.

The role of CT in acute bowel obstruction due to a supravesical hernia, a case report from Nepal

Introduction and importance: Supravesical hernias are rare internal hernias but potential cause of small bowel obstruction. The clinical features are often non-specific, preoperative diagnosis is very difficult and is often diagnosed intraoperatively. The exact pathogenesis is unclear with the major risk factors of prematurity, a positive family history, male gender, smoking habits leading to decreased collagen production, advancing age, and conditions characterized by defective collagen synthesis Case presentation: We are reporting a case of small bowel obstruction secondary to a supravesical hernia, in a 78-year-old male presented with central abdominal pain, vomiting and obstipation. Ultrasonography of the abdomen and pelvis identified a marked dilation of the small bowel loop with multiple loops of dilated jejunum and ileum in contrast-enhanced CT scan of the abdomen and pelvis with lead point from the terminal ileum. Exploratory laparotomy was done with the diagnosis of left posterior a left posterior superior vesical hernia with small bowel obstruction. Clinical discussion: The case focuses supravesical hernia as a rare yet life-threatening etiology of small bowel obstruction, emphasizing the importance of clinical suspicion when patients present with signs and symptoms of bowel obstruction. While diagnosis often occurs intraoperatively, the utilization of computed tomography (CT) scans in emergency settings can provide valuable insights into the location, potential causes, and condition of the herniated bowel sac. The case highlights the pivotal role of computed tomography (CT) scans in diagnosis and emphasizes the need for multidisciplinary cooperation among clinicians, radiologists, and surgeons. Conclusion: Early intervention ensures better outcomes and prevents irreversible bowel damage, underscoring the importance of a comprehensive approach to patient care.

High-resolution repolarization changes preceding short-coupled ectopy in idiopathic ventricular fibrillation, and effects of quinidine

Abstract Background Idiopathic ventricular fibrillation (VF) is linked to early repolarization, increased repolarization heterogeneity, and (short-coupled) premature ventricular complexes (PVCs). Quinidine, an antiarrhythmic drug with class-IA and -III effects, reduces the occurrence of PVCs and VF, but its effects on repolarization have not yet been studied at the whole-heart level in idiopathic-VF patients. Purpose To study dynamic changes in repolarization preceding short-coupled PVCs using noninvasive electrocardiographic imaging (ECGI) in a patient with idiopathic VF, and the antiarrhythmic effects of quinidine. Methods ECGI was performed during sinus rhythm in a 61-year-old male with an ICD (secondary prevention; 2.5 mg nebivolol daily) two days after recurrent idiopathic VF (Fig. A). This was done 1) at baseline, 2 minutes before short-coupled ectopy ("baseline"); 2) at baseline, 10 seconds before the short-coupled PVC ("pre PVC"); and 3) at 2 hours after start of quinidine 200 mg ("on-quinidine"). The ECGI procedure consisted of a 224-electrode body surface potential map and a contrast-enhanced CT scan to obtain torso and heart geometries. After reconstruction of epicardial unipolar electrograms (UEGs), local activation and repolarization times (ATs and RTs) were derived from UEGs by assessing the steepest downslope of the QRS complex and steepest upslope of the T waves, respectively, of 10-second signal-averaged beats. AT and RT duration (first to last AT or RT) were assessed. Results At baseline, QRS duration and QT interval measured 107 ms and 343 ms, respectively, on the standard 12-lead ECG. ECGI-derived epicardial AT duration was 72 ms, and RT histogram span 92 ms. The coupling interval of the PVC that triggered VF in the ICD readout was 340 ms (Fig. A). During 44 minutes of ECGI, 157 short-coupled PVCs from the moderator-band region were recorded (Fig. B; no tachycardia or VF). Just prior to a PVC, epicardial early repolarization at the PVC origin decreased by 26 ms (star in Figs. C-E), and the RT histogram broadened to 109 ms (Fig. E). While on-quinidine, (25 minutes; QRS duration 107 ms, QT interval 419 ms), epicardial repolarization was prolonged (Fig. C/D), also at the site of abnormal impulse formation. Quinidine had increased the epicardial AT duration to 79 ms, and RT histogram span to 133 ms. PVCs were completely suppressed. The patient remained free of sustained arrhythmias while on-quinidine. Conclusion(s) In this case of short-coupled idiopathic VF, epicardial early repolarization shortened momentarily prior to abnormal impulse formation. We found dynamic substrate-trigger characteristics that likely facilitate reentrant excitation. Quinidine prolonged the duration of epicardial activation and repolarization, suppressing the ectopy and VF recurrence.

Massive mandibular ameloblastoma masquerading malignancy: A unique case

Ameloblastomas are odontogenic tumours that arise from the maxilla and mandible. They are mostly benign but can seldom turn malignant. Their low incidence (<1-3%) and ambiguous presentation can often pose a diagnostic dilemma for the clinician. They are mostly diagnosed with the help of contrast-enhanced computed tomography scans and confirmed by characteristic findings on histopathological examination. We present a case of a 14-year-old boy presenting with a firm to hard external swelling on the right side of his face and extensive intraoral mass, which showed features of a bony malignancy but was subsequently diagnosed with ameloblastoma.

Colonic diverticular bleeding due to a rupture of an ileocolic artery pseudoaneurysm secondary to colonic diverticulitis.

A 53-year-old woman with a history of recurrent right lower quadrant pain presented with slightly bloody stools in April 2023. She was initially diagnosed with acute diverticulitis using an abdominal computed tomography (CT) scan and was treated conservatively. On the second day, however, she reported significant hematochezia. A subsequent contrast-enhanced CT scan revealed an extravasation in the ascending colon, which was promptly managed with colonoscopy. Despite initial hemostasis, she experienced recurrent bleeding. Another contrast-enhanced CT scan revealed a pseudoaneurysm with ongoing extravasation in the same area. Angiography confirmed a pseudoaneurysm in a branch of the ileocolic artery, which was successfully treated by embolization. She was discharged after an 18day hospital stay. This case highlights a pseudoaneurysm caused by diverticulitis.

Comparison of Surgical Outcomes between Endoscopeassisted Evacuation and Conventional Burr Hole Aspiration of Brain Abscess at a Tertiary Care Hospital

Background: Brain abscess is a major health problem with a reasonable morbidity and mortality rate. Objective: The objective of this study was to compare the efficacy between endoscope-assisted evacuations of brain abscess with burr hole aspiration method in a tertiary health care center. Methodology: This non-randomized clinical trial was conducted in the Department of Neurosurgery at Dhaka Medical College Hospital, Dhaka, Bangladesh during the period of July 2016 to December 2017. Patients with the age group of more than or equal to 18 years of both gender presented with brain abscess were enrolled in this study. The endoscope-assisted evacuation of abscess was done on group A patients and burr hole aspiration was done on group B patients. Outcome of the patients was assessed using GCS and MRC muscle power grading and by GOS. Patients were evaluated by contrast enhanced CT scan of head at pre-operative, 1st and 30th postoperative day. Both groups received best available medical treatment along with surgery. Results: The mean age of was 13.0 ± 6.3 years in burr hole group and is 13.1 ± 6.4 years in endoscope-assisted group. The patients presented with GCS was 66.7% in burr hole group and 93.3% in endoscope assisted group. The study showed e”75.0% evacuation of brain abscess at 1st post-operative day in 13(92.9%) patients in endoscope-assisted group and 5(33.3%) patients in burr hole group. The study showed mortality rate of 6.7% in both the groups. Mean residual volume at 30th post operative day was 0.75ml in endoscope-assisted group and 1.75ml in burr hole aspiration group. Conclusion: In conclusion endoscope-assisted procedure has better rate of abscess evacuation, less chance of residual and repeated surgeries than conventional burr hole. Bang. J Neurosurgery 2023; 13(1): 14-19

A Guide to Contrast-Enhanced Computed Tomography in Adult Patients Supported With Extracorporeal Membrane Oxygenation.

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) fundamentally alters patient physiology and blood flow relevant to contrast delivery for computed tomography (CT) imaging. Here, we present a comprehensive guide to contrast-enhanced CT scanning in adult ECMO patients, addressing common questions related to contrast delivery via the ECMO circuit, and modifications to ECMO settings and scanning techniques, to avoid non-diagnostic CT scans. The approach is described in detail for patients supported on VA ECMO, with the return cannula sited in the femoral artery. Lesser modifications required for veno-venous ECMO (VV ECMO) are included in the supplemental material. Establishing a common understanding between the intensive care clinician, the CT radiographer, and the radiologist, concerning the patient's blood-flow-physiology, is the overarching goal. Our stepwise approach facilitates clear communication around modifications to the ECMO pump settings, contrast route and rate, as well as the scanning technique, for each individual scenario.

A case of hyalinizing trabecular tumor of the thyroid: diagnostic significance of PAX8-GLIS3 fusion

BackgroundHyalinizing trabecular tumor (HTT) is an uncommon follicular cell-derived thyroid tumor classified as a low-risk neoplasm by the World Health Organization Classification of Tumors of Endocrine Organs, 5th edition. The PAX8-GLIS3 gene fusion is reportedly a pathognomonic genetic alteration of HTT.Case presentationA 43-year-old Japanese female was incidentally discovered to have an 8-mm, well-defined, hypoechoic mass in the left lobe of the thyroid gland by ultrasound examination. Contrast-enhanced computed tomography scan revealed a solid mass exhibiting slight homogeneous enhancement in the lower pole of the thyroid gland. The mass was diagnosed as atypia of undetermined significance by fine-needle aspiration cytology. The patient underwent left hemithyroidectomy with routine central compartment dissection. Histologic findings revealed tumor cells with elongated nuclei and intranuclear pseudoinclusions arranged with trabeculae architecture or small nests in hyalinized stroma. Weak membranous and cytoplasmic staining was found by MIB1 (Ki-67) immunostaining. The final diagnosis was HTT of the thyroid gland. Next-generation sequencing genetic analysis of a surgical specimen revealed no pathologic mutations, including BRAF, H/K/NRAS, or RET-PTC fusions. The PAX8-GLIS3 fusion was detected by RT-PCR.ConclusionsA rare case of HTT was demonstrated through imaging, cytologic, histologic and molecular investigations. PAX8-GLIS3 fusion detected by RT-PCR and Sanger sequencing was confirmed to be a genetic hallmark of HTT.

Added value of 40 keV virtual monoenergetic images for diagnosing malignant pleural effusion on chest CT.

This study aimed to evaluate the added value of 40 keV virtual mono-energetic images (VMIs) obtained from dual-layer detector CT (DLCT) for diagnosing malignant pleural effusion (MPE) in patients presenting with unilateral pleural effusion on chest CT. This retrospective study included 75 patients with unilateral pleural effusion who underwent contrast-enhanced chest CT scans using DLCT. Quantitative and qualitative assessments of the visibility of pleural thickening were conducted on both conventional 120 kVp images and 40 keV VMIs. Two independent radiologists reviewed chest CT scans with or without 40 keV VMIs to detect pleural nodules or nodular thickening for the diagnosis of MPE. Diagnostic performances were compared and independent predictors of MPE were identified through multivariate logistic regression analysis using CT and clinicopathologic findings. Pleural thickening associated with MPE demonstrated a higher contrast-to-noise ratio value and greater visual conspicuity in 40 keV VMIs compared to benign effusions (p < 0.05). For both readers, the use of 40 keV VMIs significantly improved (p < 0.05) the diagnostic performance in terms of sensitivity and area under the curve (AUC) for diagnosing MPE through the detection of pleural nodularity. Inter-observer agreements between the two readers were substantial for both 120 kVp images alone and the combined use of 40 keV VMIs. Initial cytology results and pleural nodularity at 40keV were identified as independent predictors of MPE. The use of 40 keV VMIs from DLCT can improve diagnostic performance of readers in detecting MPE among patients with unilateral pleural effusion.

Tracking Wall Characteristics of Necrotic Pancreatic Fluid Collections in Acute Pancreatitis on Serial Contrast-Enhanced Computed Tomography

Abstract Background Encapsulated pancreatic fluid collection (PFC) is a requisite for endoscopic drainage procedures. The 4-week threshold for defining walled-off necrosis does not capture the dynamic process of encapsulation. We aim to investigate the changes in the wall characteristics of PFC in acute necrotizing pancreatitis (ANP) by comparing baseline contrast-enhanced computed tomography (CECT) with follow-up CT scans. Methods This retrospective study comprised consecutive patients with ANP who underwent a baseline CECT within first 2 weeks and follow-up CECT in the third to fifth weeks of illness. Presence, extent, and encapsulation thickness (defined as enhancing wall around the collection) on baseline CECT were compared with follow-up CT (done in the third–fifth weeks of illness). Results Thirty patients (19 males and 11 females; mean age 41.5 ± 13.5 years) were included in the study. The mean time to first CECT was 10 ± 3.6 days. There were 58 collections. The most common site was the lesser sac (n = 29), followed by the left pararenal space (n = 15). At baseline CT, 52 (89.7%) collections had varying degree of encapsulation (15.3%, complete encapsulation). Complete encapsulation was seen in 52 and 82.6% collections in third and fourth week, respectively. All collections in fifth week and beyond were encapsulated. The wall was thicker on follow-up CECT scans (p &lt; 0.01). The mean wall thickness was not significantly associated with the degree of encapsulation (p = 0.417). There was no significant association between the site and degree of encapsulation (p = 0.546). Conclusion Encapsulation is dynamic and collections may get “walled off” before 4 weeks. Walled-off collections should be defined based on imaging rather than a fixed 4-week revised Atlanta classification threshold.

Impact of aortic root geometry and degree of aortic calcification on outcomes of patients undergoing TAVI procedure.

Adequate differentiation of calcifications in contrast-enhanced CT scans remains difficult to assess TAVI parameters. The size of the aortic leaflets has not been taken into account so far in present studies. The aim of our study was to establish a new method for optimized quantification of the aortic valve calcification degree in contrast-enhanced CT scans for better preoperative prediction of postoperative paravalvular leak after TAVI. We retrospectively analyzed preoperative contrast-enhanced CT scans of patients who underwent TAVI in our institution between 2014 and 2017. Calcium volume was quantified by a method using contrast enhanced computer tomography (3mensio-Structural Heart-7.2 software) with different iodine contents for better discrimination of contrast agent from calcium and by an individually set Houndsfield Unit (HU) threshold with 50HU above the individually determined reference value. Calcium volume was correlated with surface area of each aortic cusp. Perioperative variables were analyzed. All patients (n = 150) with severe aortic stenosis were treated with TAVI implantation. Overall incidence of postoperative trace to moderate PVL was 37%. The amount of calcium correlated with the incidence of PVL. In a logistic regression analysis total volume of calcification (p = .032) as well as calcification of each aortic cusp (NC_p = .001; RC_p < .001; LC_p = .001) were independent predictors. Calcification degree as well as its correlation with the surface area of each aortic cusp significantly influence incidence of PVL. Our new method improves preoperative quantification of the calcification degree by use of contrast agents with different iodine contents and thereby helps to improve patients' outcomes.

Automated Analysis of Split Kidney Function from CT Scans Using Deep Learning and Delta Radiomics.

Background: Differential kidney function assessment is an important part of preoperative evaluation of various urological interventions. It is obtained through dedicated nuclear medical imaging and is not yet implemented through conventional Imaging. Objective: We assess if differential kidney function can be obtained through evaluation of contrast-enhanced computed tomography(CT) using a combination of deep learning and (2D and 3D) radiomic features. Methods: All patients who underwent kidney nuclear scanning at Mayo Clinic sites between 2018-2022 were collected. CT scans of the kidneys were obtained within a 3-month interval before or after the nuclear scans were extracted. Patients who underwent a urological or radiological intervention within this time frame were excluded. A segmentation model was used to segment both kidneys. 2D and 3D radiomics features were extracted and compared between the two kidneys to compute delta radiomics and assess its ability to predict differential kidney function. Performance was reported using receiver operating characteristics, sensitivity, and specificity. Results: Studies from Arizona & Rochester formed our internal dataset (n = 1,159). Studies from Florida were separately processed as an external test set to validate generalizability. We obtained 323 studies from our internal sites and 39 studies from external sites. The best results were obtained by a random forest model trained on 3D delta radiomics features. This model achieved an area under curve (AUC) of 0.85 and 0.81 on internal and external test sets, while specificity and sensitivity were 0.84,0.68 on the internal set, 0.70, and 0.65 on the external set. Conclusion: This proposed automated pipeline can derive important differential kidney function information from contrast-enhanced CT and reduce the need for dedicated nuclear scans for early-stage differential kidney functional assessment. Clinical Impact: We establish a machine learning methodology for assessing differential kidney function from routine CT without the need for expensive and radioactive nuclear medicine scans.

Abstract PO4-04-09: Incidence, prevalence, risk factors, and impact of fatty liver disease in metastatic HR+/HER2− breast cancer patients treated with Endocrine Therapy and CDK 4/6 Inhibitor

Abstract Background: In patients with early-stage breast cancer (BC), non-alcoholic fatty liver disease (NAFLD) is associated with increased recurrence, cardiovascular events, and non-cancer death. Endocrine therapy increases the risk of NAFLD. The impact of cyclin-dependent kinases 4/6 inhibitors (CDKi) combined with endocrine therapy on NAFLD and prognostic association in metastatic breast canceris unknown. Here, we characterize the incidence, prevalence, risk factors, and treatment outcomes of NAFLD in women with metastatic HR+/HER2- BC. Methods: We conducted a retrospective cohort study of patients with advanced HR+/HER2- BC receiving first line endocrine and CDKi at Princess Margaret Cancer Centre, Toronto, Canada between January 2018 – June 2022. Patients were excluded if they had liver disease, prior chemotherapy, or no access to CT scans. Demographic, treatment, toxicity, and survival data were extracted. Liver Attenuation Index (LAI) on contrast-enhanced portal venous phase CT scan was utilized.NAFLD was defined as LAI &amp;gt;25 HU. Univariable binary-logistic regression analysis wasused to assess independent predictive factors of NAFLD. Statistical significance was defined as p&amp;lt; 0.05. Quantitative significance was defined by the Burnand criteria. Time to treatment failure (TTF) was assessed using Cox proportional hazards modeling. Results: Of approximately 90 eligible patients, 40 are included in this analysis. Baseline demographics included median age 61 years, 72% post-menopausal, 58% de-novo metastatic disease, and 27% visceral disease. Of 40 patients, 28 (70%) had NAFLD at anytime (12 at baseline and 16 incident). Associations with NAFLD are shown in Table 1. Presence of NAFLD was associated quantitatively but not statistically with age &amp;gt; 65 (OR 2.6), post-menopausal status (OR 2.6), and inversely associated with prior chemotherapy (OR 0.27) and visceral disease (OR 0.38). Lack of NAFLD at any time was significantly associated with worse TTF (mean TTF 497 versus 1228 days, HR=4.28, 95% CI: 1.89-9.68, p&amp;lt; 0.001). Patients without NAFLD at baseline also had a worse TTF (mean 903 vs 1186 days) compared to those with it at baseline, but this difference was not statistically significance (HR=1.93, 95%CI: 0.77-4.83, p= 0.163). No significant differences were found in grade 3/4 adverse events. Patients who have presented NAFLD at any time received an average of 1.36 subsequent lines of therapy compared to 2.08 in those without. Discussion &amp; Conclusion: This analysis demonstrated an association between presence of NAFLD and longer TTF. This may reflect reverse causation whereby longer exposure to ET and CDKi increases the observation of NAFLD or that these are distinct populations with different molecular pathways leading to differences in response to treatment and prognosis. It is noteworthy that the median time to develop NAFLD in the incident group was 339 days, and the group that never developed NAFLD was on treatment longer than this. Overexpression of CDK 4/6 pathway, could increase sensitivity and duration to treatment with CDKi but produce adverse metabolic changes of increased lipid synthesis, as described in pre-clinical models. If this hypothesis is confirmed, synergistically addressing these metabolic changes with physical exercise, dietary, or pharmacological interventions may improve these patients’ fitness for subsequent lines of therapy. Table 1 Citation Format: Diego Malon Gimenez, Consolacion Molto Valiente, Shopnil Prasla, Danielle Cuthbert, Abhenil Mittal, Faris Tamimi, Massimo Di Iorio, Meredith Li, Neha Pathak, Eitan Amir, Kartik Jhaveri, Michelle Nadler. Incidence, prevalence, risk factors, and impact of fatty liver disease in metastatic HR+/HER2− breast cancer patients treated with Endocrine Therapy and CDK 4/6 Inhibitor [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-04-09.

Feasibility Analysis of Individualized Low Flow Rate Abdominal Contrast-Enhanced Computed Tomography in Chemotherapy Patients: Dual-Source Computed Tomography With Low Tube Voltage.

The aim of the study is to investigate the feasibility of using dual-source computed tomography (CT) combined with low flow rate and low tube voltage for postchemotherapy image assessment in cancer patients. Ninety patients undergoing contrast-enhanced CT scans of the upper abdomen were prospectively enrolled and randomly assigned to groups A, B, and C (n = 30 each). In group A, patients underwent scans at 120 kVp with 448 mgI/kg. Patients in group B underwent scans at 100 kVp with 336 mgI/kg. Patient in group C underwent scans at 70 kVp with of 224 mgI/kg. Quantitative measurements including the CT number, standard deviation of CT number, signal-to-noise ratio, contrast-to-noise ratio, subjective reader scores, and the volume and flow rate of contrast agent were evaluated for each group. There was no statistically significant difference in the subjective image scores within the three groups except for the kidney (all P > 0.05). Group C showed significantly higher CT values, lower noise levels, and higher signal-to-noise ratio and contrast-to-noise ratio values in the majority of the regions of interest compared to the other groups (P < 0.05). In group C, the contrast agent dose was decreased by 46% compared to group A (79.48 ± 12.24 vs 42.7 ± 8.6, P < 0.01), and the contrast agent injection rate was reduced by 22% (2.7 ± 0.41 vs 2.1 ± 0.4, P < 0.01). The use of 70 kVp tube voltage combined with low iodine flow rates prove to be a more effective approach in solving the challenge of compromised blood vessels in postchemotherapy tumor patients, without reducing image quality and diagnostic confidence.

Patterns of collateral arteries to the spinal cord after thoracoabdominal aortic aneurysm repair.

To evaluate postoperative patterns of collateral arteries to the spinal cord during occlusion of the segmental arteries supplying the artery of Adamkiewicz (AKA). Between April 2011 and December 2022, 179 patients underwent thoraco-abdominal aortic aneurysm repair; 141 had an identifiable AKA on preoperative multidetector computed tomography (MDCT) scans, 40 underwent thoraco-abdominal aortic aneurysm replacement (TAAR), and 101 underwent thoracic endovascular aortic repair (TEVAR). New postoperative collateral blood pathways invisible on preoperative contrast-enhanced computed tomography scans were identified in 42 patients (10 patients in TAAR vs 32 patients in TEVAR) who underwent preoperative and postoperative MDCT scanning for AKA identification. The thoracodorsal and segmental arteries were the main collateral pathways in both groups. Th9-initiated collaterals were the most common. Collaterals from the internal thoracic artery were observed in the TEVAR group but not in the TAAR group. One patient in the TEVAR group experienced postoperative paraparesis, which was not observed in the TAAR group. Postoperative paraplegia was more common in the non-Th9-origin group, but this difference was non-significant. Thoracodorsal and segmental arteries may be important collateral pathways after TEVAR and TAAR. For thoracodorsal arteries, preserving the thoracodorsal muscle during the approach would be crucial; for segmental arteries, minimizing the area to be replaced or covered would be paramount. An AKA not initiated at the Th9 level poses a high risk of postoperative paraplegia.

Evaluating aortomesenteric parameters in a tertiary center of Nepal for superior mesenteric artery syndrome diagnosis and risk factors: cross-sectional study.

This study examines aortomesenteric angle (AMA) and distance (AMD), which are critical in superior mesenteric artery (SMA) syndrome. Addressing the scarcity of SMA cases, the research explores potential links with lower BMI and aims to establish normative data for diagnostic and predictive purposes, using contrast-enhanced computed tomography (CT) scans across various BMI and sex categories. A retrospective quantitative cross-sectional study was conducted on 189 patients undergoing abdominal contrast-enhanced CT scans between December 2019 and December 2020. Ethical clearance was obtained, and participants provided informed consent. Exclusion criteria targeted specific medical histories. Patient demographics, BMI categories, and imaging data were recorded. Helical 128-slice CT scans were employed, with sagittal-oblique multiplanar reconstructions for parameter assessments. Statistical analysis utilized SPSS 26.0, including Pearson correlation coefficients and mean calculations. The study reveals a mean AMA of 54.07°±8.53° and a mean distance of 16.25±3.44 mm. Elevated BMI is found to positively correlate with AMA and distance, indicating that higher BMI values may augment these parameters, with an additional positive correlation observed between AMA and distance. No significant correlations are found with patient age or sex. The study concludes that decreased BMI may pose a potential risk for SMA syndrome, as evidenced by the observed correlations with aortomesenteric parameters. Understanding these normal values in the Nepalese population is critical for accurate diagnoses and predictions using CT scans. The research highlights the impact of demographic factors on these parameters and emphasizes their significance in clinical assessments related to SMA syndrome.

Amoebic liver abscess in an adult Nigerian: A case report

Background: Amoebic liver abscess (ALA) is a parasitic infection caused by Entamoeba histolytica. ALA is a significant health concern, particularly in regions with poor sanitation and hygiene practices. Radiological imaging plays a crucial role in the diagnosis and management of ALA. Methods: We present a case report of a 40-year-old male patient with ALA. The patient presented to a radio diagnostic centre in Umuahia with right upper quadrant abdominal pain, fever,diarrhea and weight loss. Radiological evaluation was performed using abdominal ultrasound and contrast-enhanced CT scan. The imaging findings were correlated with clinical presentation and laboratory investigations. Results: The radiological findings revealed a focal hypoechoic lesion in the right hepatic lobe with ill-defined margins and internal echoes suggestive of liquefaction. The contrast-enhanced CT scan confirmed the presence of a well-defined, hypodense lesion with peripheral enhancement and central hypoattenuation. No evidence of biliary ductal dilatation or vascular invasion was observed. Based on the findings, a diagnosis of ALA was made, and the patient was initiated on intravenous metronidazole therapy. Follow-up imaging demonstrated a decrease in abscess size and resolution of internal echoes, indicating a positive response to treatment. Conclusion: Radiological imaging, including ultrasound and CT scan, plays a pivotal role in the diagnosis and management of ALA. The characteristic imaging findings, such as hypoechoic lesions with internal echoes and peripheral enhancement with central hypoattenuation, aid in differentiating ALA from other hepatic lesions. Early diagnosis and prompt initiation of appropriate therapy are crucial for favorable patient outcomes. Radiological follow-up allows monitoring of treatment response and guides further management decisions.

Immediate management of a stable patient with unstable pelvis.

The diagnosis of a traumatic unstable pelvis in a stable patient is a temporary concept depending on when we see the patient, as all patients presenting with hemorrhagic shock have hemodynamic stability until they become unstable. As a rule, the more unstable the pelvic fracture is, the higher the risk of bleeding and hemodynamic instability it has. Therefore, in unstable pelvic fractures, hemodynamic stability should be a diagnosis by exclusion. For bleeding detection in stable patients, an immediate one-stage contrast-enhanced CT scan is the appropriate diagnosis test; however, since CT scan radiation is always an issue, X-rays should be considered in those cases of hemodynamically stable patients in whom there is a reasonable suspicion that no unsafe bleeding is going on. Pelvic fracture classification is essential as usually there is an association between the injury mechanism, the fracture displacement, and the hemodynamic stability. Anteroposterior and, particularly, vertical traumatisms have much more proclivity to provoke major pelvic displacement and bleeding. The use of a pelvic binder, as early as possible including pre-hospital management, should be standard in high-impact blunt trauma patients independently of the trauma mechanisms. External fixation is the preferred method of stabilization in case of open fractures, and, in closed ones, when the schedule for definite osteosynthesis prolongs because of the patient's general condition. If possible, immediate percutaneous sacroiliac screw insertion for unstable pelvic fractures produce excellent results even in open fractures.

Acute superior mesenteric artery thrombosis in a 34-year-old male with thrombophilia: a case report

Introduction: Thrombophilic state, marked by extensive formation of blood clots within the vascular system poses a formidable peril, leading to loss of circulatory integrity and systemic well-being. Superior mesenteric artery (SMA) thrombosis is a serious medical disorder characterized by the obstruction of the arterial blood flow to the gastrointestinal tract, which is associated with significant morbidity and mortality. The condition has a plethora of etiological causes. Vague abdominal pain is a common clinical manifestation, and there is a very high mortality rate.Case Presentation: A 34-year-old Pakistani male presented with rapidly worsening acute abdominal pain over a 10-hour period. Clinical examination revealed elevated blood pressure, while other vital signs remained within normal limits. Abdominal examination findings were inconclusive compared to the patient's severe abdominal pain complaint. Contrast-enhanced CT scan indicated a large thrombus in the superior mesenteric artery with radiological features suggestive of intestinal ischemia, extending from the duodeno-jejunal flexure to the mid-transverse colon. Subsequently, the patient underwent exploratory laparotomy with extensive bowel resection and received anticoagulant therapy. He subsequently experienced compensated right lower limb ischemia, treated conservatively with high-dose anticoagulant therapy. Within days, bowel anastomotic leak developed, requiring multiple surgeries. Eventually, the patient progressed to septic shock, followed by multiorgan failure, culminating in a fatal cardiac arrest.Conclusion: Acute mesenteric ischemia, a rare abdominal emergency with an incidence of 6 per 100,000, is associated with a substantial mortality rate, ranging from 58% to 93% among diagnosed cases. The challenges posed by SMA thrombosis include diagnostic complexities, as it frequently manifests with symptoms disproportionate to clinical signs, and results in catastrophic complications, necessitating high suspicion index and prompt intervention.

Contribution of Red Blood Cells and Platelets to Blood Clot Computed Tomography Imaging and Compressive Mechanical Characteristics.

Thrombus computed tomography (CT) imaging characteristics may correspond with thrombus mechanical properties and thus predict thrombectomy success. The impact of red blood cell (RBC) content on these properties (imaging and mechanics) has been widely studied. However, the additional effect of platelets has not been considered. The objective of the current study was to examine the individual and combined effects of blood clot RBC and platelet content on resultant CT imaging and mechanical characteristics. Human blood clot analogues were prepared from a combination of preselected RBC volumes and platelet concentrations to decouple their contributions. The resulting clot RBC content (%) and platelet content (%) were determined using Martius Scarlet Blue and CD42b staining, respectively. Non-contrast and contrast-enhanced CT (NCCT and CECT) scans were performed to measure the clot densities. CECT density increase was taken as a proxy for clinical perviousness. Unconfined compressive mechanics were analysed by performing 10 cycles of 80% strain. RBC content is the major determinant of clot NCCT density. However, additional consideration of the platelet content improves the association. CECT density increase is influenced by clot platelet and not RBC content. Platelet content is the dominant component driving clot stiffness, especially at high strains. Both RBC and platelet content contribute to the clot's viscoelastic and plastic compressive properties. The current in vitro results suggest that CT density is reflective of RBC content and subsequent clot viscoelasticity and plasticity, and that perviousness reflects the clot's platelet content and subsequent stiffness. However, these indications should be confirmed in a clinical stroke cohort.