Abdominopelvic Computed Tomography Research Articles

Catecholamine crisis after endoscopic ultrasound-guided fine-needle biopsy: A case report

The function and use of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) has developed in recent years, particularly in distinguishing malignant from benign masses. It is a generally safe method that can be completed without any uncommon complications. Here, although no complications from EUS-FNB were noted, we report about an unexpected catecholamine crisis that occurred after EUS-FNB. A 60-year-old man visited an outpatient clinic with an incidental diagnosis of a retroperitoneal mass on his last abdominopelvic computed tomography (APCT) scan taken at the time of a previous liver abscess treatment. On presentation, the patient showed no symptoms. A retroperitoneal mass was incidentally discovered on APCT, and risk for lymphoma, gastrointestinal tumor, or neuroendocrine tumor was noted on the APCT reading. EUS-FNB was performed on retroperitoneal mass. The procedure was completed without any complications; however, the patient's condition deteriorated due to hemodynamic instability and cardiovascular collapse. During intensive care unit (ICU) treatment, the biopsy results were found to be paraganglioma. Catecholamine crisis occurred after biopsy of paraganglioma. The case presented here gives a caution of complication that may occur after EUS-FNB. Although EUS-FNB is known to be relatively safe, careful evaluation is required when performing biopsy of lesions around the aorta.

Importance of communication of CT indication for imaging yield in patients with gastrointestinal bleed

PurposeThe indications for requesting a diagnostic test are important for the selection and timing of imaging protocols. We sought to evaluate the diagnostic yield and impact on patient disposition when evaluating computed tomography (CT) of the abdomen and pelvis in adult patients presenting with gastrointestinal bleeding (GIB) to the Emergency Department (ED). MethodsThis study was an observational cohort study of consecutive adult ED patients with ICD10 codes related to GIB between 5/5/2018 and 6/1/2020. CT reports were reviewed for indications, exam type and findings. Reports were classified as positive (active bleeding, recent bleeding or suspected etiology for GIB), negative or other significant findings. Methodological guidelines for reporting observational studies were followed (STROBE). ResultsAmong 943 patients with GIB during the study period, 33% (n = 312) had an abdominopelvic CT ordered. Most CTs included contrast, 64.1% (n = 200) used a single portal venous phase and 28.9% (n = 90) were multi-phase. CT identified active bleeding in 4.2% (n = 13/312) and intraluminal blood in 2.9% (n = 9/312) patients. Patients that had GIB indications on the CT order (n = 142) were more likely to receive a multiphase study compared to those without GIB indication (n = 94) (43.0% vs. 8.5%, difference 34.5%, 95% CI 23.7% to 43.7%, p < 0.0001). Patients that received multiphase studies were more likely to have a source of GIB identified compared to single-phase (18.9% vs 1.5%, OR 15.3, 95% CI 4.4 to 53.7, p < 0.0001). In 40.3% (n = 117/290) of patients without bleeding, an intra-abdominal cause for their symptoms was identified. Those with GIB or with an identified cause were more likely to be admitted. ConclusionsOne-third of patients evaluated in the ED with GIB had a CT ordered. Active GIB was detected more often when multiphase exams were performed. Multiphase exams are done more often if GIB is listed in the CT indication. When a CT is positive, patients are more likely to be admitted or observed. Accurate indications are critical to optimize exam performance.

Abdominopelvic CT Imaging Findings in the Emergency Department in Patients With HIV Positive Status: Single Institute Experience

ObjectiveTo assess emergency department (ED) abdominopelvic computed tomography (CT) imaging utilization and findings in patients with known human immunodeficiency virus (HIV) positive status. Materials and MethodsA retrospective chart review of imaging, clinical, and laboratory data was performed for HIV positive patients who demonstrated HIV-related findings on abdominopelvic CT imaging performed within the ED. ResultsOne hundred and eighty-eight patients with 522 CT scans of the abdomen and/or pelvis were reviewed. 47 patients with HIV presenting to the ED on 82 separate occasions were included in this study (mean age 43.3 years). Patients presented to the ED with infectious/inflammatory disease (n = 54) or history of HIV-related malignancy or new/worsening HIV-related malignancy (n = 28). The most common findings on abdominopelvic CT were anorectal pathology including anorectal abscess or proctitis (n = 22), followed by colitis (n = 19). Findings of HIV-associated malignancy were less common, including anal/rectal cancer (n = 7), Kaposi's sarcoma (n = 4), and lymphoma (n = 2). At the time of ED visit, 25.6% (n = 21) of patients had acquired immunodeficiency syndrome (AIDS). Higher WBC counts were found in the infectious/inflammatory group (P = 0.021) and patients without AIDS (P = 0.0159), while lower WBC counts were associated with new or worsening malignancy (P = 0.007) and AIDS (P = 0.0000). Patients with AIDS were more likely to be deceased at the time of our study. ConclusionsThe majority of ED visits within our population were attributed to infectious/inflammatory etiologies. CT findings demonstrated predominantly infectious/inflammatory processes, with anorectal pathology being the most common. Findings of malignancy on CT were less common, while opportunistic infections and AIDS-defining malignancies were uncommon.

Assessment of Adult's Abdominopelvic Computed Tomography Radiation Doses in Amhara Region, Ethiopia.

Computed Tomography plays a priceless role for diagnostic and therapeutic purpose; however, applying an optimized Computed Tomography Technique to produce qualified image while delivering minimum radiation dose to patients is the common challenge. The main objective of this study was to establish local diagnostic reference levels for adult patients who visited abdominopelvic Computed Tomography examination. A total of 158 patients who had taken abdominopelvic Computed Tomography examination from three selectedAmhara region hospitals were investigated. Both prospective and retrospective techniques of data collection were used while collecting the data in the entire sample. Two GE - Optima Computed Tomography 540 (16 slices) and one Phillips - Brilliance (64slices), were employed during data collections. Data for patient demographics scan protocols, Computed Tomography dose descriptors and machine specifications were collected and analyzed by using SPSS software version 26. The third quartile estimated computed tomography dose index volume and dose length product, which is the local Diagnostic Reference Levels, were 12 mGy and 1904 cm.mGy respectively. The investigated local Diagnostic Reference Levels of Computed Tomography Dose index volume (mGy) was comparable to other international Diagnostic Reference Levels. However, the third quartile value of dose length product (cm.mGy) was higher than other reported international Diagnostic Reference Levels. The values of local Diagnostic Reference Levels presented in this work can be used as a baseline upon which future dose measurements can be compared in Amhara region.

Identifying Axial Spondyloarthritis in Patients With Inflammatory Bowel Disease Using Computed Tomography.

The diagnosis of axial spondyloarthritis (axSpA) is hampered by diagnostic delay. Computed tomography (CT) undertaken for nonmusculoskeletal (non-MSK) indications in patients with inflammatory bowel disease (IBD) offers an opportunity to identify sacroiliitis for prompt rheumatology referral. This study aims to identify what proportion of patients with IBD who underwent abdominopelvic CT for non-MSK indications have axSpA and to explore the role of a standardized screening tool to prospectively identify axSpA on imaging. Abdominopelvic CT scans of patients with verified IBD, aged 18 to 55 years, performed for non-MSK indications were reviewed by radiologists for the presence of CT-defined sacroiliitis (CTSI), using criteria from a validated CT screening tool. All patients identified were sent a screening questionnaire, and those with self-reported chronic back pain (CBP), CBP duration of greater than 3 months, and age of onset of less than 45 years were invited for rheumatology review. CTSI was identified in 60 out of 301 (19.9%) patients. Out of these 60 patients, 32 (53%) responded to an invitation to participate, and 27 out of 32 (84.3%) were enrolled. Of these, 8 had a preexisting axSpA diagnosis and 5 did not report CBP. In total, 14 patients underwent rheumatology assessment, and 3 out of 14 (21.4%, 95% CI 4.7-50.8) had undiagnosed axSpA. In total, 11 out of 27 (40.7%, 95% CI 22.4-61.2) patients had a rheumatologist-verified diagnosis of axSpA. In this study, 5% (3/60) of patients with IBD undergoing abdominopelvic CT for non-MSK indications with CTSI were found to have undiagnosed axSpA and, overall, 18.3% (11/60) were found to have axSpA. This reveals a significant hidden population of axSpA and highlights the need for a streamlined pathway from sacroiliitis detection to rheumatology referral.

Visceral obesity as a risk factor of incisional hernia after single-port laparoscopic gynecologic surgery

ObjectiveWe aimed to evaluate associations between abdominal fat distribution (AFD) parameters and incisional hernia (IH) in patients who underwent transumbilical single-port laparoscopic surgery (SPLS) for gynecological disease. MethodsMedical records of 2116 patients who underwent SPLS for gynecological disease at Daejeon St. Mary's Hospital between March 2014 and February 2021 were reviewed. Among 21 (1.0%) patients who developed IH requiring surgical treatment after SPLS, 18 had preoperative abdominopelvic computed tomography (CT) images. As a control group, we randomly selected 72 patients who did not develop IH and who had undergone preoperative abdominopelvic CT scan, matched to test patients by type of surgery. Total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA), visceral-to-subcutaneous fat ratio (VSR), and waist circumference (WC) were measured at the level of the third lumbar vertebral body on the preoperative abdominopelvic CT images, using National Institutes of Health (NIH) ImageJ version 1.53 k. ResultsReceiver operating curve analysis showed that VFA has the highest predictive value for IH among AFD parameters (AUC = 0.749, 95% CI 0.630–0.869, p < 0.001). Univariate analysis showed that age, BMI, hypertension, dyslipidemia, TFA, VFA, VSR and WC were significant factors for IH. In multivariate analysis, only high VFA was identified as an independent risk factor for IH (HR 6.18, 95% CI 1.13–33.87, p = 0.04), whereas BMI, TFA, SFA, VSR, and WC failed to show statistical significance. ConclusionWe could find high VFA as an independent risk factor of IH in patients who underwent SPLS for gynecologic disease.

Low-dose abdominopelvic computed tomography in patients with lymphoma: An image quality and radiation dose reduction study.

This study aimed to evaluate image quality, the detection rate of enlarged lymph nodes, and radiation dose exposure of ultralow-dose and low-dose abdominopelvic computed tomography (CT) in patients with lymphoma. Patients with lymphoma who underwent abdominopelvic CT using dual-source scanner were retrospectively recruited from a single center. CT images were obtained at 90 kVp dual-source mode reformatted in three data sets using the advanced modelled iterative reconstruction algorithm: 100% (standard-dose CT), 66.7% (low-dose CT), and 33.3% (ultralow-dose CT). Two radiologists analyzed subjective image quality and detection of abdominal enlarged lymph nodes on ultralow-dose, low-dose, and standard-dose CT blindly and independently. The results were compared with reference standards. Three readers (two radiologists and one hematologist) reviewed overall image quality and spleen size. In total, 128 consecutive CT scans (77 complete response, 44 partial response, 6 progressive disease, and 1 initial evaluation) from 86 patients (64 B-cell lymphoma, 14 T/NK-cell lymphoma, and 8 Hodgkin’s lymphoma cases) were assessed. The enlarged lymph node-based detection rates for two readers were 97.0% (96/99) and 94.0% (93/99) on standard-dose CT, 97.0% (96/99) and 94.0% (93/99) on low-dose CT, and 94.0% (93/99) and 89.9% (89/99) on ultralow-dose CT. Overall image quality was 3.8 ± 0.5, 3.9 ± 0.5, and 4.1 ± 0.5 on ultralow-dose CT; 4.7 ± 0.4, 4.6 ± 0.5, and 4.8 ± 0.3 on low-dose CT; and 4.8 ± 0.4, 4.7 ± 0.4, and 4.9 ± 0.2 on standard-dose CT, according to two radiologists and one hematologist, respectively. Intraclass correlation coefficients of spleen size were 0.90 (95% confidence interval [CI], 0.87–0.93), 0.91 (95% CI, 0.88–0.93), and 0.91 (95% CI, 0.88–0.93) on ultralow-dose, low-dose, and standard-dose CT, respectively. Mean effective radiation doses of standard-dose, low-dose, and ultralow-dose CT were 5.7 ±1.8 mSv, 3.8 ± 1.2 mSv, and 1.9 ± 0.6 mSv, respectively. Our findings suggest that ultralow-dose and low-dose CT, even with radiation doses reduced by 66.7% and 33.3%, respectively, maintained adequate image quality. These imaging modalities may be employed for follow-up lymphoma evaluation in consideration of the long surveillance periods.

Clinical study on ureteritis observed in contrast-enhanced computed tomography in the emergency department.

ObjectiveWe aimed to investigate the causes and clinical and laboratory features of patients with ureteritis observed on intravenous contrast-enhanced abdominopelvic computed tomography (APCT) conducted in the emergency department (ED).MethodsAll APCTs conducted in the ED from November 2017 to November 2020 were investigated for the presence of ureteritis. The incidence of ureteritis, presumed cause of ureteritis, and clinical as well as laboratory features of patients with ureteritis were retrospectively analyzed.ResultsUreteritis was observed in 422 out of 7,386 patients (5.7%) who underwent APCTs. The two main reasons for undergoing APCT in the ED were abdominal pain (49%) and infection focus workup (33%). The first major cause of ureteritis was urinary tract infection (UTI) (351 of 422, 83%). Most patients (85%) were febrile, but 208 (59%) exhibited no urinary symptoms such as dysuria, increased frequency, or residual urine sense. The second major cause of ureteritis was ureteral stones (42 of 422, 10%). Thirty-two of 42 patients (76%) had simple obstructive uropathy, while 24% of patients had a combined infection along with an obstruction. Other rare causes were malignancy and the spread of adjacent inflammation.ConclusionUreteritis was a common finding observed in 5.7% of patients who underwent APCTs at the ED, and most of them were secondary to UTIs and ureteral stones. UTIs can cause ureteritis even without typical symptoms or signs suggestive of UTI, and diagnosis without an APCT can be difficult. More liberal use of APCTs should be considered when the cause of fever is difficult to diagnose.

CT features associated with underlying malignancy in patients with diagnosed mesenteric panniculitis

PurposeThe purpose of this study was to identify abdominal computed tomography (CT) features associated with underlying malignancy in patients with mesenteric panniculitis (MP). Materials and methodsThis single-institution retrospective longitudinal cohort study included patients with MP and a minimum 1-year abdominopelvic CT follow-up or 2-year clinical follow-up after initial abdominopelvic CT examination. Two radiologists, blinded to patients’ medical records, conjointly reviewed CT-based features of MP. Electronic medical records were reviewed for newly diagnosed malignancies with the following specific details: type (lymphoproliferative disease or solid malignancy), location (possible mesenteric drainage or distant), stage, time to diagnosis. An expert panel of three radiologists and one hemato-oncologist, who were blinded to the initial CT-based MP features, assessed the probability of association between MP and malignancy based on the malignancy characteristics. ResultsFrom 2006 to 2016, 444 patients with MP were included. There were 272 men and 172 women, with a median age of 64 years (age range: 25–89); the median overall follow-up was 36 months (IQR: 22, 60; range: 12–170). A total of 34 (8%) patients had a diagnosis of a new malignancy; 5 (1%) were considered possibly related to the MP, all being low-grade B-cell non-Hodgkin lymphomas. CT features associated with the presence of an underlying malignancy were the presence of an MP soft-tissue nodule with a short axis >10 mm (P < 0.0001) or lymphadenopathy in another abdominopelvic region (P < 0.0001). Associating these two features resulted in high diagnostic performance (sensitivity 100%; [95% CI: 57–100]; specificity 99% [95% CI: 98–100]). All related malignancies were identified. ConclusionFurther workup to rule out an underlying malignancy is only necessary in the presence of an MP soft-tissue nodule >10 mm or associated abdominopelvic lymphadenopathy.

Preoperative Computed Tomography Morphological Features Indicative of Incisional Hernia Formation After Abdominal Surgery.

To investigate key morphometric features identifiable on routine preoperative computed tomography (CT) imaging indicative of incisional hernia (IH) formation following abdominal surgery. IH is a pervasive surgical disease that impacts all surgical disciplines operating in the abdominopelvic region and affecting 13% of patients undergoing abdominal surgery. Despite the significant costs and disability associated with IH, there is an incomplete understanding of the pathophysiology of hernia. A cohort of patients (n=21,501) that underwent colorectal surgery was identified, and clinical data and demographics were extracted, with a primary outcome of IH. Two datasets of case-control matched pairs were created for feature measurement, classification, and testing. Morphometric linear and volumetric measurements were extracted as features from anonymized preoperative abdominopelvic CT scans. Multivariate Pearson testing was performed to assess correlations among features. Each feature's ability to discriminate between classes was evaluated using 2-sided paired t testing. A support vector machine was implemented to determine the predictive accuracy of the features individually and in combination. Two hundred and twelve patients were analyzed (106 matched pairs). Of 117 features measured, 21 features were capable of discriminating between IH and non-IH patients. These features are categorized into three key pathophysiologic domains: 1) structural widening of the rectus complex, 2) increased visceral volume, 3) atrophy of abdominopelvic skeletal muscle. Individual prediction accuracy ranged from 0.69 to 0.78 for the top 3 features among 117. Three morphometric domains identifiable on routine preoperative CT imaging were associated with hernia: widening of the rectus complex, increased visceral volume, and body wall skeletal muscle atrophy. This work highlights an innovative pathophysiologic mechanism for IH formation hallmarked by increased intra-abdominal pressure and compromise of the rectus complex and abdominopelvic skeletal musculature.

Yield of pelvic CT in emergency department patients undergoing CT torso for generalized or multiple complaints.

To evaluate the utility of pelvic computed tomography (CT) in emergency department (ED) patients undergoing chest CT angiogram (CTA) for chest pain or suspected pulmonary embolism (PE) followed by abdominopelvic CT in the same session for additional multisystem or generalized complaints. This retrospective study included consecutive adult ED patients from January 2017 to December 2019 who underwent CTA for suspected PE followed by portovenous abdominopelvic CT for multisystem or generalized complaints. Patient demographics, vitals, laboratory values, exam indication, malignancy history, and recent surgery/intervention were recorded. CT reports were reviewed for acute chest, abdomen, and/or pelvic pathology. There were 400 patients with 243 (61%) women and mean age of 59.8years. Acute pelvic findings were seen in 11% (45/400). In 53% (24/45) of these, pelvic pathology could be diagnosed based on the abdominal portion of the CT. Five percent (21/400) of patients demonstrated isolated acute pelvic findings with 86% of these (18/21) clinically suspected prior to imaging. Acute pelvic pathology was associated with female gender (p = 0.015) and elevated white blood cell count (WBC) (p = 0.03). Specific pelvic CT indications and female gender were significantly associated with (p = 0.02 each) and independent predictors of isolated acute pelvic pathology. In ED patients undergoing chest CTA for chest pain or suspected PE combined with abdominopelvic CT, the presence of acute pelvic-related pathology not visualized on abdominal CT is low. For this ED patient cohort, pelvic CT may not be necessary in men with normal WBC and a low pre-imaging clinical suspicion for acute pelvic pathology.

Effect of more versus less frequent abdominopelvic computed tomography follow-up testing on overall survival in patients with stage II or III colon cancer.

3604 Background: Patients with colon cancer undergo an abdominopelvic computed tomography (AP-CT) scan surveillance every 6-12 months for five years after surgery. However, evidence of survival benefit from more intensive AP-CT patients in stage II and III colon cancer is still elusive. Methods: A total of 2,137 patients with stage II-III colon cancer who received curative aim surgery were analyzed in the Yonsei Cancer Registry Database between Jan 1, 2005, to Dec 31, 2015. The surveillance start date was defined as 90 days after curative resection or one day after adjuvant chemotherapy. All patients had at least one AP-CT for two years after the surveillance period. The average interval of AP-CT per patient was calculated as the postoperative surveillance duration divided by the number of AP-CT examinations. Patients who underwent AP-CT with an average interval of 6 months and 12 months were assigned to the high-frequent and low-frequent surveillance groups. Association of AP-CT frequency and demographic factors with overall survival (OS) were evaluated. Univariate and multivariate analyses were conducted. Results: Among 2,137 patients who underwent curative aim surgery, the median intervals of AP-CT scan were 6.1 months in high-frequent surveillance and 10.8 months in the less-frequent surveillance group, respectively. The 5-year overall survival (OS) was not significantly different in both groups; however, OS was significantly longer in the high-frequent surveillance group of patients who harvested lymph nodes less than 12 in curative resection ( P = 0.015) or measured postoperative serum carcinoembryonic antigen (CEA) level higher than 5 ng/ml ( P = 0.023). Of note, high-frequent surveillance group detected liver metastasis earlier (6.7 months) than the low-frequent group, leading to more curative aim metastasectomy (28.0% vs 4.3%, P = 0.020), and significantly longer 5-year OS (62.2% vs 34.8%, P = 0.017). Multivariate analysis showed that harvesting lymph nodes less than 12 (HR = 4.37, P = 0.004) and postoperative CEA level higher than 5 ng/ml (HR = 7.39, P &lt; 0.001) were prognostic factors for overall survival. Conclusions: The average interval of AP-CT in patients with stage II-III colon cancer is not associated with improved OS. However, a high-frequent AP-CT enabled early detection of liver metastases, leading to the improved OS in high-risk patients, including the number of harvested lymph nodes less than 12 or postoperative CEA level is higher than 5 ng/ml. The risk-stratified approach is warranted to guide postoperative colon cancer surveillance.

Prevalence of Paget's disease of bone: review of consecutive abdominopelvic CT scans and literature.

Previous studies suggest an overall decrease of Paget's disease of bone (PDB) prevalence. However, a large number of asymptomatic patients make previously reported prevalence likely underrepresented. To evaluate the prevalence of PDB in our patient population. We retrospectively identified 1295 (mean age = 59 years; age range = 18-98 years) consecutive abdominopelvic computed tomography (CT) scans over a 15-day period in 2014. Abdominopelvic CT images were reviewed to assess for the presence of PDB in the lower thoracic spine, lumbar spine, pelvis, or proximal femora. This prevalence was compared with prevalence reported in earlier literature using Fisher's exact test. Of the included patients, 5/1295 (0.39%) patients had imaging findings of PDB on abdominopelvic CT. Those five patients were all aged ≥55 years and had pelvic bone involvement, with one patient having additional involvement of multiple lower thoracic vertebral bodies. In our studied cohort, 812/1295 (62.7%) patients were aged ≥55 years, which corresponds to a prevalence of 0.62% (5/812) of PDB in patients aged ≥55 years. When accounting for fact that bones of the pelvis are involved in 40%-91% of patients with PDB, the prevalence is estimated at 0.43%-0.98% in the total adult population and estimated at 0.68%-1.55% in older adults. The prevalence was greater than two studies before 1960, and less than some studies during 1960-2019. We found that the prevalence of PDB on abdominopelvic CTs was 0.39% of all adult patients with an increase after the age of 55 years.

A Deep Residual U-Net Algorithm for Automatic Detection and Quantification of Ascites on Abdominopelvic Computed Tomography Images Acquired in the Emergency Department: Model Development and Validation.

BackgroundDetection and quantification of intra-abdominal free fluid (ie, ascites) on computed tomography (CT) images are essential processes for finding emergent or urgent conditions in patients. In an emergency department, automatic detection and quantification of ascites will be beneficial.ObjectiveWe aimed to develop an artificial intelligence (AI) algorithm for the automatic detection and quantification of ascites simultaneously using a single deep learning model (DLM).MethodsWe developed 2D DLMs based on deep residual U-Net, U-Net, bidirectional U-Net, and recurrent residual U-Net (R2U-Net) algorithms to segment areas of ascites on abdominopelvic CT images. Based on segmentation results, the DLMs detected ascites by classifying CT images into ascites images and nonascites images. The AI algorithms were trained using 6337 CT images from 160 subjects (80 with ascites and 80 without ascites) and tested using 1635 CT images from 40 subjects (20 with ascites and 20 without ascites). The performance of the AI algorithms was evaluated for diagnostic accuracy of ascites detection and for segmentation accuracy of ascites areas. Of these DLMs, we proposed an AI algorithm with the best performance.ResultsThe segmentation accuracy was the highest for the deep residual U-Net model with a mean intersection over union (mIoU) value of 0.87, followed by U-Net, bidirectional U-Net, and R2U-Net models (mIoU values of 0.80, 0.77, and 0.67, respectively). The detection accuracy was the highest for the deep residual U-Net model (0.96), followed by U-Net, bidirectional U-Net, and R2U-Net models (0.90, 0.88, and 0.82, respectively). The deep residual U-Net model also achieved high sensitivity (0.96) and high specificity (0.96).ConclusionsWe propose a deep residual U-Net–based AI algorithm for automatic detection and quantification of ascites on abdominopelvic CT scans, which provides excellent performance.

Comparison of a Deep Learning-Based Reconstruction Algorithm with Filtered Back Projection and Iterative Reconstruction Algorithms for Pediatric Abdominopelvic CT.

ObjectiveTo compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms.Materials and MethodsPost-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods.ResultsThe NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001).ConclusionFor pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

A Huge 5kg-Intra-Abdominal Ancient Schwannoma with A Recurrence-A Case Report

Introduction- This is a rare case of a recurrent huge intrabdominal Ancient Schwannoma, the size of which has not been reported before. This case report aims to enrich the literature on cases of undiagnosed abdominal masses. Clinical features-The patient complained of huge abdominal distension, weight loss, and breathlessness of 4 months duration. The important clinical findings were multiple cutaneous painless swellings, hyperpigmented patches on the trunk, and a mass occupying the whole of the abdomen. Management-A diagnosis of visceral manifestation of neurofibromatosis was made to rule out an intra-abdominal malignancy. Preoperative Abdominal Computed Tomography (CT) scan revealed a huge intrabdominal mass while a CT-guided biopsy showed a Benign Mesenchymal tumor. He had an exploratory laparotomy, and the mass was totally excised. The recovery was uneventful, and the outcome was excellent. Histopathology showed that the tumor was a Schwannoma with no malignancy. However, 5 months after, the swelling recurred and he was eventually lost to follow up. Conclusion- The rarity of Intra-abdominal Schwannomas and absent or non-specific signs and symptoms present the surgeon with a diagnostic dilemma. Preoperative Abdominopelvic CT scan, Ultrasound scan, and Magnetic Resonance Imaging are necessary imaging modalities. Complete excision at surgery reduces recurrence. Close follow-up is essential.

Less Emergency Department Abdominopelvic Computed Tomography for Patients With Crohn's Disease: A New Scoring System.

In recent years, the use of abdominal pelvic computed tomography (APCT) in the emergency department (ED) for patients with Crohn's disease (CD) has risen steadily. Thus, exposing these patients to recurrent radiation, despite studies showing that only 30% to 40% had significant findings in ED APCT. Our aim was to find clinical and laboratory variables that can predict substantial findings on ED APCT, which may require invasive intervention. We analyzed ED visits of patients with known CD that underwent an emergent APCT for gastrointestinal complaints, over a 10-year period. Patients with positive and negative findings in the APCT were compared in order to evaluate independent effects of different variables, including patients' characteristics, CD history, ED complaints, and laboratory tests. In 44% of 183 ED visits, there were significant findings on ED APCT, however, only 22% of them underwent invasive intervention. Laboratory tests: C-reactive protein >50 mg/L, neutrophil count >75%, platelet count >350×10 9 /L, and ileocolon location at diagnosis were all positive predicting factors. Whereas, smoking or ED complaints of diarrhea/fever reduced the risk for significant findings. Using the 7 most significant predicting factors, we built an easy to use scoring system-Crohn Assessment Tool for CT upon Hospitalization (CATCH) for ED clinicians. This scoring system could have prevented unnecessary ED APCT from 42% of the patients in our study, without missing those who required invasive intervention.

Evaluating the impact of 18F-FDG-PET-CT on risk stratification and treatment adaptation for patients with muscle-invasive bladder cancer (EFFORT-MIBC): a phase II prospective trial

BackgroundThe outcome of patients with muscle-invasive bladder cancer (MIBC) remains poor, despite aggressive treatments. Inadequate primary staging, classically performed by computed tomography (CT)-imaging, could lead to inappropriate treatment and might contribute to these poor results. Although not (yet) adapted by international guidelines, several reports have indicated the superiority of 18F-fluorodeoxyglucose-positron emission tomography-CT (18F-FDG-PET-CT) compared to CT in the detection of lymph node and distant metastases. Thereby the presence of extra-vesical disease on 18F-FDG-PET-CT has been correlated with a worse overall survival. This supports the hypothesis that 18F-FDG-PET-CT is useful in stratifying MIBC patients and that adapting the treatment plan accordingly might result in improved outcome.MethodsEFFORT-MIBC is a multicentric prospective phase II trial aiming to include 156 patients. Eligible patients are patients with histopathology-proven MIBC or ≥ T3 on conventional imaging treated with MIBC radical treatment, without extra-pelvic metastases on conventional imaging (thoracic CT and abdominopelvic CT/ magnetic resonance imaging (MRI)). All patients will undergo radical local therapy and if eligible neo-adjuvant chemotherapy. An 18F-FDG-PET-CT will be performed in addition to and at the timing of the conventional imaging. In case of presence of extra-pelvic metastasis on 18F-FDG-PET-CT, appropriate intensification of treatment with metastasis-directed therapy (MDT) (in case of ≤3 metastases) or systemic immunotherapy (> 3 metastases) will be provided. The primary outcome is the 2-year overall survival rate. Secondary endpoints are progression-free survival, distant metastasis-free survival, disease-specific survival and quality of life. Furthermore, the added diagnostic value of 18F-FDG-PET-CT compared to conventional imaging will be evaluated and biomarkers in tumor specimen, urine and blood will be correlated with primary and secondary endpoints.DiscussionThis is a prospective phase II trial evaluating the impact of 18F-FDG-PET-CT in stratifying patients with primary MIBC and tailoring the treatment accordingly. We hypothesize that the information on the pelvic nodes can be used to guide local treatment and that the presence of extra-pelvic metastases enables MDT or necessitates the early initiation of immunotherapy leading to an improved outcome.Trial registrationThe Ethics Committee of the Ghent University Hospital (BC-07456) approved this study on 11/5/2020. The trial was registered on ClinicalTrials.gov (NCT04724928) on 21/1/2021.

Radiation dose and cancer risks from radiation exposure during abdominopelvic computed tomography (CT) scans: comparison of diagnostic and radiotherapy treatment planning CT scans.

In the present study, radiation doses and cancer risks resulting from abdominopelvic radiotherapy planning computed tomography (RP-CT) and abdominopelvic diagnostic CT (DG-CT) examinations are compared. Two groups of patients who underwent abdominopelvic CT scans with RP-CT (n = 50) and DG-CT (n = 50) voluntarily participated in this study. The two groups of patients had approximately similar demographic features including mass, height, body mass index, sex, and age. Radiation dose parameters included CTDIvol, dose-length product, scan length, effective tube current, and pitch factor, all taken from the CT scanner console. The ImPACT software was used to calculate the patient-specific radiation doses. The risks of cancer incidence and mortality were estimated based on the BEIR VII report of the US National Research Council. In the RP-CT group, the mean ± standard deviation of cancer incidence risk for all cancers, leukemia, and all solid cancers was 621.58 ± 214.76, 101.59 ± 27.15, and 516.60 ± 189.01 cancers per 100,000 individuals, respectively, for male patients. For female patients, the corresponding risks were 742.71 ± 292.35, 74.26 ± 20.26, and 667.03 ± 275.67 cancers per 100,000 individuals, respectively. In contrast, for DG-CT cancer incidence risks were 470.22 ± 170.07, 78.23 ± 18.22, and 390.25 ± 152.82 cancers per 100,000 individuals for male patients, while they were 638.65 ± 232.93, 62.14 ± 13.74, and 575.73 ± 221.21 cancers per 100,000 individuals for female patients. Cancer incidence and mortality risks were greater for RP-CT than for DG-CT scans. It is concluded that the various protocols of abdominopelvic CT scans, especially the RP-CT scans, should be optimized with respect to the radiation doses associated with these scans.

Abdominal Muscles and Metabolic Syndrome According to Patient Sex: A Retrospective Cross-Sectional Study.

Computed tomography (CT) is a reference method for measuring skeletal muscle mass, and the amount of fat in the skeletal muscle can be calculated based on CT attenuation. This study aimed to comprehensively investigate the effect of muscle quality and quantity on metabolic syndrome (MetS) according to sex. This retrospective cross-sectional study enrolled 8081 individuals aged ≥20 years who underwent self-referral abdominopelvic CT at our hospital. The total abdominal muscle area (TAMA), low-attenuation abdominal muscle area (LAMA), normal-attenuation abdominal muscle area (NAMA), and extramyocellular lipid area (EMCLA) were measured using cross-sectional CT data of the L3 lumbar vertebrae. The TAMA and NAMA showed negative correlations with risk factors for MetS and a positive correlation with high-density lipoprotein cholesterol, whereas the LAMA and EMCLA showed an inverse trend in both the sexes (p < 0.001). After adjusting for various factors, a higher LAMA index and the ratio of LAMA to TAMA were associated with a higher prevalence of MetS. High TAMA indices were associated with a lower prevalence of MetS. Furthermore, muscle quality and quantity were associated with the prevalence of MetS in both males and females. However, the LAMA showed a stronger association with MetS in males than in females.