Contrast-enhanced Computed Tomography Scan Research Articles

Study of Risk Factors and Image Findings of Isolated Abdominal Incidentally Detected Aortic Dissection.

Isolated abdominal aortic dissection (IAAD) has been reported to account for 1.1%-4.1% of all aortic dissections. If detected late, it is associated with a risk of aortic rupture. We investigated the risk factors and characteristic imaging findings of incidentally discovered IAAD using abdominal ultrasonography (AUS) during health check-up and hereby report our findings. The study sample included 41 patients with abdominal aortic abnormalities identified by AUS performed during a health check-up at our hospital and who were diagnosed with IAAD by contrast-enhanced computed tomography (CT); in addition, 205 patients were included in the nonevent group. Furthermore, risk factors and characteristic imaging findings of IAAD were examined retrospectively. Compared with the nonevent group, smoking and fatty liver were observed significantly more frequently in the IAAD group. Ultrasound findings indicated an intimal flap in 35 cases (85.4%), whereas CT scan revealed displacement of intimal calcifications in 32 cases (78.0%). Compared with the nonevent group, there were significantly more cases of fatty liver and smoking habits in the IAAD group. In older patients with risk factors for fatty liver and smoking habits, if IAAD is suspected, it is important to monitor the abdominal aorta using ultrasonography during health check-ups.

Inter-observer variability in assessing image-defined risk factors: implications for risk stratification in locoregional abdominopelvic neuroblastoma.

Risk stratification for locoregional neuroblastoma partially relies on image-defined risk factors (IDRFs). This study aimed to evaluate how inter-observer variability in assessing IDRFs impacts risk stratification in locoregional abdominopelvic neuroblastoma. A retrospective analysis was conducted on 123 patients who underwent upfront contrast-enhanced CT scans. Two radiologists independently assessed the presence of IDRFs. Patients were staged as either L1 (IDRF-negative) or L2 (IDRF-positive) according to the International Neuroblastoma Risk Group Staging System. Based on the radiologists' evaluations, 97 cases with sufficient clinical data were classified into risk groups using the revised Children's Oncology Group neuroblastoma risk classifier. The kappa values and 95% confidence intervals (CIs) were calculated to assess inter-radiologist agreement on IDRF evaluation and risk stratification. There was low agreement between radiologists in assessing L1/L2 status with a kappa value of 0.28 (95% CI: 0.14-0.42). However, agreement for evaluating the number of IDRFs was good, with an intraclass correlation coefficient of 0.73 (95% CI: 0.64-0.80). Based on the first radiologist's evaluation, 13 patients were classified as low-risk, 52 as intermediate-risk, and 32 as high-risk. Based on the second radiologist's evaluation, 37 patients were classified as low-risk, 37 as intermediate-risk, and 23 as high-risk. The kappa value for risk stratification between the two radiologists was 0.47 (95% CI: 0.33-0.62). Inter-observer variability in assessing IDRF presence may affect risk stratification in locoregional abdominopelvic neuroblastoma.

AI-enabled cardiac chambers volumetry in non-contrast coronary artery calcium CT scans vs. contrast-enhanced coronary CT angiography scans in the same patients

Abstract Introduction We have developed an AI-enabled automated volumetry of cardiac chambers (AutoChamber) that works both on non-contrast ECG-gated cardiac CT scans used for coronary artery calcium (CAC) score, and non-contrast non-gated lung cancer screening CT scans. We have recently reported the agreement between AutoChamber measurements vs cardiac MRI measurements. Here we report AutoChamber results on non-contrast CAC scans and contrast enhanced coronary CT angiography (CTA). Methods We have obtained CT images from a previously published study in which 131 cases underwent non-contrast CAC and contrast enhanced CCTA at research institute. The cases consisted of 52.4% women with ages 55.0 ± 10.1 years. The cardiac chambers volume in 131 cases of contrast enhanced CCTA were measured using automated chamber volumetry by Philips Brilliance Volume v 4.5; Philips Healthcare. Results The correlations between Philips’ automated chamber volumetry in contrast enhanced CCTA scans versus AutoChamber automated volumetry in non-contrast CAC scans for left atrium (LA), left ventricle (LV), right atrium (RA), right ventricle (RV), and left ventricular wall (LVW) volume were 0.73, 0.65, 0.85, 0.93, 0.90, respectively (P for all <0.01). Conclusion AI-enabled AutoChamber volumetry based on non-contrast cardiac scans is feasible, and correlates reasonably well with contrast-enhanced cardiac CT scans. Further studies are warranted to reproduce these results and explore the add-on value of AutoChamber to CAC scans.

Establishing Local Diagnostic Reference Levels for Head Computed Tomography Examinations

Background/Objectives: Head Computed Tomography (CT) is an essential diagnostic tool for identifying brain pathologies and visualizing blood vessels. However, CT exposes patients to ionizing radiation, making it necessary to establish local diagnostic reference levels (DRLs) to ensure patient safety. This study aimed to establish DRLs for head CT scans and assess the influence of patient characteristics on radiation dose. Methods: A retrospective analysis was conducted on 2043 non-contrast and 488 contrast-enhanced head CT scans performed between 1 July 2023 and 31 March 2024 using a SIEMENS SOMATOM Definition Edge machine. Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) values were analyzed, with DRLs set at the 75th percentile. The influence of gender, height, and weight on radiation dose was also evaluated. Results: The DRL for both non-contrast and contrast-enhanced scans was 58.18 mGy for CTDIvol and 1018.11 mGy·cm for DLP per acquisition. Total DLP was 2046.09 mGy·cm for contrast-enhanced and 1027.99 mGy·cm for non-contrast scans. No significant correlation was found between patient characteristics and radiation dose, allowing for a uniform DRL to be established. Conclusions: Uniform DRLs were successfully established for head CT scans, ensuring safe radiation doses for both non-contrast and contrast-enhanced studies. The lack of correlation between patient-specific factors and dose supports the use of standardized DRLs, contributing to optimized radiation safety in head CT diagnostics.

Ultra-High-Resolution Photon-Counting Detector CT Benefits Visualization of Abdominal Arteries: A Comparison to Standard-Reconstruction.

This study aimedto investigate the potential benefit of ultra-high-resolution (UHR) photon-counting detector CT (PCD-CT) angiography in visualization of abdominal arteries in comparison to standard-reconstruction (SR) images of virtual monoenergetic images (VMI) at low kiloelectron volt (keV).We prospectively included 47 and 47 participants to undergo contrast-enhanced abdominal CT scans within UHR mode on a PCD-CT systemusing full-dose (FD) and low-dose (LD) protocols, respectively. The data were reconstructed into six series of images: FD_UHR_Br48, FD_UHR_Bv56, FD_UHR_Bv60, FD_SR_Bv40, LD_UHR_Bv48, and LD_SR_Bv40. The UHR reconstructions were performed with three kernels (Bv48, Bv56, and Bv60) within 0.2mm. The SR were virtual monoenergetic imaging reconstruction with Bv40 kernel at 40-keV within 1mm. Each series of axial images were reconstructed into coronal and volume-rendered images. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of seven arteries were measured. Three radiologists assessed the image quality, and visibility of nine arteries on all the images.SNR and CNR values of SR images were significantly higher than those of UHR images (P < 0.001). The SR images have higher ratings in image noise (P < 0.001), but the FD_UHR_Bv56 and FD_UHR_Bv60 images has higher rating in vessel sharpness (P < 0.001). The overall quality was not significantly different among FD_VMI_40keV, LD_VMI_40keV, FD_UHR_Bv48, and LD_UHR_Bv48 images (P > 0.05) but higher than those of FD_UHR_Bv56 and FD_UHR_Bv60 images (P < 0.001). There is no significant difference of nine abdominal arteries among six series of images of axial, coronal and volume-rendered images (P > 0.05).To conclude, 1-mm SR image of VMI at 40-keV is superior to 0.2-mm UHR regardless of which kernel is used to visualize abdominal arteries, while 0.2-mm UHR image using a relatively smooth kernel may allow similar image quality and artery visibility when thinner slice image is warranted.

A case of non-occlusive mesenteric ischemia following hepatocellular carcinoma rupture.

Hepatocellular carcinoma (HCC) rupture is a severe complication, yet there is limited literature on cases complicated by subsequent non-occlusive mesenteric ischemia (NOMI). A 77-year-old man presented to our hospital with abdominal pain and shock. Arterial phase computed tomography (CT) hepatic arteriography revealed a 77-mm HCC in the left lobe with active extravasation, and the feeding artery was embolized. Although the abdominal pain initially subsided after the procedure, it recurred the next day. A contrast-enhanced CT scan revealed pneumatosis intestinalis and decreased enhancement of the small intestinal wall. The patient underwent resection of the affected segment of the small intestine and was ultimately diagnosed with NOMI based on pathological findings. This is the first reported case of NOMI following HCC rupture. Given the high mortality associated with these conditions, clinicians should be aware of this rare complication and ensure comprehensive evaluation and timely intervention to improve patient outcomes.

Substituting with alternativeiodinated contrast medium to prevent recurrent adverse drug reactions associated with its use: a meta-analysis.

To systematically review and meta-analyze the recurrent rate of iodinated contrast medium (ICM)-associated adverse drug reactions (ADRs) and the preventive effect of using alternative ICM lacking a common carbamoyl side chain. A systematic literature search was conducted in the MEDLINE and EMBASE databases to identify studies that investigated the recurrence rate of ICM-associated ADRs or hypersensitivity reactions (HSRs). Studies that included patients who subsequently underwent contrast-enhanced computed tomography scans after their index reactions were included, while studies with overlapping cohorts were excluded. The first search was conducted on November 10, 2023. The pooled recurrence rate of ICM-associated ADR was determined using the DerSimonian-Laird random-effects model. Subgroup analyses were also conducted based on the substitution of ICM, with particular consideration given to the N-(2,3-dihydroxypropyl) carbamoyl side chain. A total of ten original articles were included in the analysis, collectively spanning from June 2001 to March 2021. The pooled recurrence rate of ICM-associated ADR was not significantly different from that of ICM-associated HSR (16.6% [95% CI, 7.8-31.9%] vs. 15.5% [95% CI, 10.8-21.8%], p = 0.87). In the subgroup analyses, the pooled odds ratio for ICM-associated recurrent ADR when using a different ICM compared with using the same ICM was 0.31 (95% CI, 0.21-0.45), which means a 69% reduction. Moreover, the pooled odds ratio for ICM-associated recurrent ADR when substituting ICMs with different side chains compared with substituting with common side chains was 0.65 (95% CI, 0.52-0.82), which means an additional 35% reduction. Substituting with an alternative ICM led to a 69% reduction in recurrent ADRs, with an additional 35% reduction observed when using ICM lacking a common carbamoyl side chain. Question No standardized guidelines exist for replacing previously used iodinated contrast medium (ICM) to prevent recurrent adverse reactions. Findings Using alternative contrast medium with a different carbamoyl side chain prevents adverse drug reactions effectively. Clinical relevance This study advocates using alternative ICM without a common carbamoyl side chain to prevent recurrent adverse drug reactions in patients with a history of such events.

Diagnostic Performance of Computed Tomography in Laryngeal Carcinoma and its Extension

Background: Laryngeal carcinoma is a common malignant neoplasm of the head and neck with high incidence of new malignancies worldwide every year. Several imaging techniques including magnetic resonance imaging (MRI) and computed tomography (CT) scans are widely used to detect laryngeal carcinoma. Of them, CT scan is relatively cheaper, easily available and sensitive in the evaluation of laryngeal carcinoma. Objective: To find out the diagnostic performance of CT scan in laryngeal carcinoma and its extensions. Methodology: This cross-sectional study was carried out in the department of Radiology and Imaging, Dhaka Medical CollegeHospital, Dhaka, during the period of July, 2016 to June, 2018 for a period of 2(two) years. A total of 50 samples were included purposively. The enrolled patients were attending outpatient department (OPD) or admitted in indoor and referred to the Radiology and Imaging department for CT scan. All the enrolled cases had laryngectomy and resected tissues were sent for histopathological examination. Data collection was done by the principal investigator and a preformed questionnaire was used during data collection. Following completion of data collection, it was analyzed by SPSS 20.0. Results: Age range of the patients was from 18 to 84 years, with the mean age of 61.2 years + 13.4 years standard deviation and a male-female ratio of about 7.3:1. By multidetector CT scan, majority (32, 64.00%) of the tumours were found confined in a specific area with no extension, followed by 12 (24.00%) involving both supraglottic and glottic region. On the other hand, by histopathology, almost all (47, 94.00%) of the cases were found malignant and majority of the malignant cases (31, 65.96%) were found without nodal metastasis. Validity tests of CT in the diagnosis of laryngeal carcinoma revealed sensitivity, specificity, accuracy and positive predictive values of 97.9%, 66.7%, 96% and 97.9% respectively. In case of nodal metastases, the sensitivity, specificity, accuracy and positive predictive value were 93.8%, 97%, 96% and 93.8% respectively. Conclusion: Contrast enhanced CT scan has good role in detecting nodal metastases, but had complementary role in detecting laryngeal carcinoma. Journal of Monno Medical College December, 2023; 9 (2): 63-67

Primary lymphoma of mucosa associated lymphoid tissue (MALT lymphoma) in the urinary bladder mimicking recurrent urinary tract infection: a case report and literature review

We report the case of a 79-year-old woman with primary lymphoma of mucosa-associated lymphoid tissue (MALT) in the urinary bladder. The patient, with urinary frequency, urgency and suprapubic pain had several emergency room visits due to recurrent urinary tract infection. Both sonogram and cystoscopy identified bladder tumors near the bladder neck. An abdominal contrast-enhanced computed tomography scan revealed a polypoid lesion on the anterior bladder wall without enlarged lymph nodes. Transurethral resection of the bladder tumor was conducted. The pathology report confirmed extranodal marginal zone MALT lymphoma. The clinical stage was IEA. Follow-up imaging reported residual bladder tumors, prompting adjuvant radiotherapy. The patient was treated successfully and was disease-free at the 9-month follow-up visit. Primary lymphoma is an uncommon pathological subtype. Its clinical and radiological differentiation from urothelial carcinoma (UC) can be challenging, but treatment strategies differ significantly. A definitive diagnosis relies on histopathology and immunohistochemistry. Typically, bladder lymphoma has a favorable prognosis, but further research is required to identify the optimal treatment.

Segmentation-based quantitative measurements in renal CT imaging using deep learning

BackgroundRenal quantitative measurements are important descriptors for assessing kidney function. We developed a deep learning-based method for automated kidney measurements from computed tomography (CT) images.MethodsThe study datasets comprised potential kidney donors (n = 88), both contrast-enhanced (Dataset 1 CE) and noncontrast (Dataset 1 NC) CT scans, and test sets of contrast-enhanced cases (Test set 2, n = 18), cases from a photon-counting (PC)CT scanner reconstructed at 60 and 190 keV (Test set 3 PCCT, n = 15), and low-dose cases (Test set 4, n = 8), which were retrospectively analyzed to train, validate, and test two networks for kidney segmentation and subsequent measurements. Segmentation performance was evaluated using the Dice similarity coefficient (DSC). The quantitative measurements’ effectiveness was compared to manual annotations using the intraclass correlation coefficient (ICC).ResultsThe contrast-enhanced and noncontrast models demonstrated excellent reliability in renal segmentation with DSC of 0.95 (Test set 1 CE), 0.94 (Test set 2), 0.92 (Test set 3 PCCT) and 0.94 (Test set 1 NC), 0.92 (Test set 3 PCCT), and 0.93 (Test set 4). Volume estimation was accurate with mean volume errors of 4%, 3%, 6% mL (contrast test sets) and 4%, 5%, 7% mL (noncontrast test sets). Renal axes measurements (length, width, and thickness) had ICC values greater than 0.90 (p < 0.001) for all test sets, supported by narrow 95% confidence intervals.ConclusionTwo deep learning networks were shown to derive quantitative measurements from contrast-enhanced and noncontrast renal CT imaging at the human performance level.Relevance statementDeep learning-based networks can automatically obtain renal clinical descriptors from both noncontrast and contrast-enhanced CT images. When healthy subjects comprise the training cohort, careful consideration is required during model adaptation, especially in scenarios involving unhealthy kidneys. This creates an opportunity for improved clinical decision-making without labor-intensive manual effort.Key PointsTrained 3D UNet models quantify renal measurements from contrast and noncontrast CT.The models performed interchangeably to the manual annotator and to each other.The models can provide expert-level, quantitative, accurate, and rapid renal measurements.Graphical

A rare case of intestinal obstruction due to tuberculosis.

A 19-year-old previously healthy patient presented with severe abdominal pain. A contrast-enhanced CT scan identified ileal obstruction and lower left lung lobe changes suggestive of an inflammatory process. Diagnostic laparoscopy revealed ileal distension, hyperemia, and whitish nodules on the serosa. Acid-fast bacilli staining was positive, confirming Mycobacterium tuberculosis infection. The patient improved with a tuberculosis regimen. Intestinal TB often affects the ileocecal area and presents with symptoms like abdominal pain and obstruction. Diagnosis is confirmed by AFB staining, and treatment mirrors pulmonary TB, though surgery may be needed for complications.

A flexible deep learning framework for liver tumor diagnosis using variable multi-phase contrast-enhanced CT scans

BackgroundLiver cancer is a significant cause of cancer-related mortality worldwide and requires tailored treatment strategies for different types. However, preoperative accurate diagnosis of the type presents a challenge. This study aims to develop an automatic diagnostic model based on multi-phase contrast-enhanced CT (CECT) images to distinguish between hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and normal individuals.MethodsWe designed a Hierarchical Long Short-Term Memory (H-LSTM) model, whose core components consist of a shared image feature extractor across phases, an internal LSTM for each phase, and an external LSTM across phases. The internal LSTM aggregates features from different layers of 2D CECT images, while the external LSTM aggregates features across different phases. H-LSTM can handle incomplete phases and varying numbers of CECT image layers, making it suitable for real-world decision support scenarios. Additionally, we applied phase augmentation techniques to process multi-phase CECT images, improving the model’s robustness.ResultsThe H-LSTM model achieved an overall average AUROC of 0.93 (0.90, 1.00) on the test dataset, with AUROC for HCC classification reaching 0.97 (0.93, 1.00) and for ICC classification reaching 0.90 (0.78, 1.00). Comprehensive validation in scenarios with incomplete phases was performed, with the H-LSTM model consistently achieving AUROC values over 0.9.ConclusionThe proposed H-LSTM model can be employed for classification tasks involving incomplete phases of CECT images in real-world scenarios, demonstrating high performance. This highlights the potential of AI-assisted systems in achieving accurate diagnosis and treatment of liver cancer. H-LSTM offers an effective solution for processing multi-phase data and provides practical value for clinical diagnostics.

Exploring the Intersection of Blood Transfusion and Same-Day Computed Tomography Imaging: An Overview of Clinical Risks and Practices.

The use of transfusions, whether involving whole blood or specific blood components, is essential for managing various clinical conditions. Many cases are acute, often requiring post-transfusion imaging evaluation. While there is no absolute contraindication for chest imaging following blood transfusion, it should be approached cautiously. We conducted a comprehensive search across multiple databases and registries. Research studies were limited to full-text original articles, reviews, and case reports published in English, involved human subjects, and focused on the interplay between blood transfusions and contrast-enhanced imaging. Scientific analyses were excluded if they did not focus on transfusion practices in the context of imaging or failed to address issues such as hemoglobin thresholds, transfusion reactions, or the clinical implications of contrast agents. Our research fills this gap by emphasizing the need for a cautious, multidisciplinary approach to post-transfusion computed tomography (CT) scans, especially in the presence of contrast agents. This study calls for increased awareness of the heightened risk of complications, such as autoimmune hemolysis, when both procedures are performed together. New insights from our research recommend individualized assessments and close patient monitoring when combining these interventions. Nevertheless, patients need to be hemodynamically and clinically stable before undergoing CT. Discussions. Symptoms that develop within the first 24 h post-transfusion are classified as secondary post-transfusion reactions unless proven otherwise. The prevalence of side effects from same-day CT scans and blood transfusions is challenging to quantify, as few studies focus on this combination. Transfusions and contrast-enhanced CT scans share overlapping adverse reactions and carry significant risks. Acute hemolytic red blood cell transfusion reactions are among the most frequent side effects, with a prevalence of 1:12,000-38,000. Conclusion. Our study contributes new insights to the literature by filling the gap concerning the interplay between transfusions and contrast media, paving the way for more informed clinical protocols to enhance patient safety.

209 - Application value of POWER PICC as venous access in contrast enhanced CT scanning

209 - Application value of POWER PICC as venous access in contrast enhanced CT scanning

Giant intra-abdominal desmoid-type fibromatosis infiltrating into the pancreas

Abstract: Intra-abdominal desmoid-type fibromatosis is a proliferative fibroblastic lesion that constitutes 8% of all desmoid tumors and 0.03% of all neoplasm. It is histologically benign with a local aggressive nature and recurs even after excision. It can occur sporadically and or associated with familial adenomatous polyposis mutation. The present case is a 25-year-old female admitted with a chief complaint of abdominal mass gradually increasing in size in the last 6 months. Ultrasound of the whole abdomen initially suggested it to be a uterine/ovarian mass, which is further detailed by the contrast-enhanced computerized tomography (CT) scan. The CT scan showed a large heterodense intraperitoneal mass lesion measuring 34 cm × 25 cm × 16 cm with foci of calcification and necrosis. The mass extended superomedially. It displaced and compressed the stomach wall. It was abutting the peritoneum and was associated with diffuse peritoneal thickening anterolaterally. Posteriorly it was abutting small bowel loops and inferiorly extending into the pelvis and compressing the urinary bladder wall. Posterosuperiorly seems to abut the left kidney and spleen. Desmoid tumor and gastrointestinal stromal tumor (GIST) remained as differentials radiologically and then the patient underwent laparotomy. Histology and immunohistochemistry confirmed it to be fibromatosis. It is, therefore, justified to describe the tumor by considering its rarity, difficulties in diagnosis, and therapeutic ambit.

CT assessed morphological features can predict higher mitotic index in gastric gastrointestinal stromal tumors.

To investigate the correlation of the mitotic index (MI) of 1-5 cm gastric gastrointestinal stromal tumors (gGISTs) with CT-identified morphological and first-order radiomics features, incorporating subgroup analysis based on tumor size. We enrolled 344 patients across four institutions, each pathologically diagnosed with 1-5 cm gGISTs and undergoing preoperative contrast-enhanced CT scans. Univariate and multivariate analyses were performed to investigate the independent CT morphological high-risk features of MI. Lesions were categorized into four subgroups based on their pathological LD: 1-2 cm (n = 69), 2-3 cm (n = 96), 3-4 cm (n = 107), and 4-5 cm (n = 72). CT morphological high-risk features of MI were evaluated in each subgroup. In addition, first-order radiomics features were extracted on CT images of the venous phase, and the association between these features and MI was investigated. Tumor size (p = 0.04, odds ratio, 1.41; 95% confidence interval: 1.01-1.96) and invasive margin (p < 0.01, odds ratio, 4.55; 95% confidence interval: 1.77-11.73) emerged as independent high-risk features for MI > 5 of 1-5 cm gGISTs from multivariate analysis. In the subgroup analysis, the invasive margin was correlated with MI > 5 in 3-4 cm and 4-5 cm gGISTs (p = 0.02, p = 0.03), and potentially correlated with MI > 5 in 2-3 cm gGISTs (p = 0.07). The energy was the sole first-order radiomics feature significantly correlated with gGISTs of MI > 5, displaying a strong correlation with CT-detected tumor size (Pearson's ρ = 0.85, p < 0.01). The invasive margin stands out as the sole independent CT morphological high-risk feature for 1-5 cm gGISTs after tumor size-based subgroup analysis, overshadowing intratumoral morphological characteristics and first-order radiomics features. Question How can accurate preoperative risk stratification of gGISTs be achieved to supporttreatment decision-making? Findings Invasive margins may serve as a reliable marker for risk prediction in gGISTs up to 5 cm, rather than surface ulceration, irregular shape, necrosis, or heterogeneous enhancement. Clinical relevance For gGISTs measuring up to 5 cm, preoperative prediction of the metastatic risk could help select patients who could be treated by endoscopic resection, thereby avoiding overtreatment.

Radiological Assessment of Pulmonary Vascular Changes and Gastrointestinal Changes in COVID-19 Patients Referred to a Tertiary Health Care Centre in Chennai, India: A Prospective Cross-Sectional Study

Background: The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to significant morbidity and mortality worldwide since its emergence in 2019. While primarily a respiratory illness, COVID-19 can also affect other organ systems, including the vascular and gastrointestinal systems. COVID-19 infection is linked to both venous and arterial thrombosis, with numerous studies indicating a heightened risk of pulmonary embolism (PE) among patients. Autopsies have revealed pulmonary vasculature thrombosis and bowel ischemia in COVID-19 cases. Aim: This prospective cross-sectional study aimed to assess radiological pulmonary vascular changes, specifically pulmonary embolism (PE), and gastrointestinal changes in COVID-19 patients referred to a tertiary healthcare center in Chennai, India. Methods: CT pulmonary angiography (CTPA) and contrast-enhanced CT of the abdomen were conducted in 100 COVID-19 positive patients meeting the inclusion and exclusion criteria. Evaluation of pulmonary vascular changes and bowel changes was performed by a radiologist with five years of experience. Subsequently, statistical analysis was carried out to determine the significance of the relationship between COVID-19 patients and the occurrence of pulmonary vascular and bowel changes. Results: In our study, 11 patients exhibited pulmonary thromboembolism, and 7 patients showed significant bowel changes. There is a positive correlation between the prevalence of PE in COVID-19 patients. PE was diagnosed at a mean of 11 days from the onset of the disease. Out of 24 patients with severe acute respiratory illness (SARI), 7 showed PE in CTPA. Additionally, out of 10 mechanically ventilated patients, 7 had PE in CTPA. Among the 7 patients with bowel changes, 4 had PE in CTPA, indicating a significant association with PE. The observed bowel changes were attributed to intravascular thrombosis. Conclusion: Based on our findings, individuals with COVID-19 often develop pulmonary emboli and bowel changes. Multivariate analyses revealed a connection between invasive mechanical ventilation and PE. Our results suggest that patients with severe clinical manifestations of COVID-19 may also have concurrent acute PE. Thus, for these patients, utilizing contrast-enhanced CT scans instead of standard non-contrast CT scans may aid in treatment decision-making.

Primary Aortic Malignant Peripheral Nerve Sheath Tumor.

A 74year-old woman suffering 1month persisting lumbago was referred with diagnosis of thoracic aortic aneurysm. Blood examinations indicated slightly or moderately elevated noradrenaline, dopamine, and homovanillic acid with normal-range vanillylmandelic acid. Contrast-enhanced CT scans revealed a tumor, protruding both intra- and extra-luminally, in the wall of the distal descending thoracic aorta without any primary focuses in the whole body. Primary aortic sarcoma or periaortic catecholamine-producing paraganglioma infiltrating the aorta was suspected. The tumor with the normal proximal and distal aorta 2-3cm apart from it was completely resected under femoro-femoral partial cardiopulmonary bypass. Macroscopically, the tumor was originated from the aortic wall and protruded both intra- and extra-luminally. Immunohistochemically, positive S-100 and vimentin; Ki67 levels of 40%; and negative CD34, CK AE1/AE3, and SMA were identified. The aforementioned findings definitively diagnosed primary aortic malignant peripheral nerve sheath tumor, which has been never reported in the literature.

Predicting angiogenesis in adrenal pheochromocytoma: the role of modified parameters from contrast-enhanced CT

ObjectiveThe aim of this study is to investigate the value of modified parameters derived from dual-phase contrast-enhanced computed tomography (CT) in predicting angiogenesis within pheochromocytoma.MethodA total of 31 patients with pathologically confirmed pheochromocytoma underwent preoperative dual-phase contrast-enhanced CT scanning, wherein modified CT enhancement parameters, namely maximum enhancement difference (∆H) and maximum enhancement velocity (V), were quantified. Subsequently, postoperative specimens were evaluated by pathological section, while microvessel density (MVD) and vascular endothelial growth factor (VEGF) levels were counted. We conducted comparative analyses to assess disparities in maximum enhancement difference and enhancement velocity between groups characterized by high and low VEGF expression. Furthermore, correlations between maximum enhancement difference, enhancement velocity, and MVD were examined, along with an assessment of the association between maximum enhancement difference, VEGF expression, and MVD at the point of maximal enhancement difference occurrence.ResultsIn the study group, unilateral pheochromocytoma was observed in 31 cases, with 19 cases of arterial phase enhancement and 12 cases displaying venous phase enhancement. The range of maximum enhancement difference (ΔH) spanned from 24 to 102 HU, while the range of maximum enhancement velocity (V) extended from 0.40 HU/s to 4.08 HU/s. Analysis revealed a significant elevation in MVD value within the arterial phase enhancement group compared to the venous phase enhancement group. Additionally, a positive correlation was discerned between the maximum enhancement difference, V, and MVD. Notably, both ∆H and V exhibited statistically significant elevations in the high VEGF expression group relative to the low VEGF expression group. Furthermore, a positive correlation was observed between both ΔH and V and VEGF expression levels.ConclusionIncreased values of ∆H and V are indicative of heightened MVD and VEGF expression. Consequently, the modified parameters derived from dual-phase contrast-enhanced CT scanning serve as predictive markers for angiogenesis in adrenal pheochromocytoma.

The study of plain CT combined with contrast-enhanced CT-based models in predicting malignancy of solitary solid pulmonary nodules

To compare the diagnostic performance between plain CT-based model and plain plus contrast CT-based modelin the classification of malignancy for solitary solid pulmonary nodules. Between January 2012 and July 2021, 527 patients with pathologically confirmed solitary solid pulmonary nodules were collected at dual centers with similar CT examinations and scanning parameters. Before surgery, all patients underwent both plain and contrast-enhanced chest CT scans. Two clinical characteristics, fifteen plain CT characteristics, and four enhanced characteristics were used to develop two logistic regression models: model 1 (plain CT only) and model 2 (plain + contrast CT). The diagnostic performance of the two models was assessed separately in the development and external validation cohorts using the AUC. 392 patients from Center A were included in the training cohort (median size, 20.0 [IQR, 15.0–24.0] mm; mean age, 55.8 [SD, 9.9] years; male, 53.3%). 135 patients from Center B were included in the external validation cohort (median size, 20.0 [IQR, 16.0–24.0] mm; mean age, 56.4 [SD, 9.6] years; male, 51.9%). Preoperative patients with 201 malignant (adenocarcinoma, 148 [73.6%]; squamous cell carcinoma, 35 [17.4%]; large cell carcinoma,18 [9.0%]) and 326 benign (pulmonary hamartoma, 118 [36.2%]; sclerosing pneumocytoma, 35 [10.7%]; tuberculosis, 104 [31.9%]; inflammatory pseudonodule, 69 [21.2%]) solitary solid pulmonary nodules were gathered from two independent centers. The mean sensitivity, specificity, accuracy, PPV, NPV, and AUC (95%CI) of model 1 (Plain CT only) were 0.79, 0.78, 0.79, 0.67, 0.87, and 0.88 (95%CI, 0.82–0.93), the model 2 (Plain + Contrast CT) were 0.88, 0.91, 0.90, 0.84, 0.93, 0.93 (95%CI, 0.88–0.98) in external validation cohort, respectively. A logistic regression model based on plain and contrast-enhanced CT characteristics showed exceptional performance in the evaluation of malignancy for solitary solid lung nodules. Utilizing this contrast-enhanced CT model would provide recommendations concerning follow-up or surgical intervention for preoperative patients presenting with solid lung nodules.