CT Studies Research Articles

Can surgically assisted rapid palatal expansion (SARPE) be recommended over orthodontic rapid palatal expansion (ORPE) for girls above the age of14? : Acone-beam CT study on midpalatal suture maturation.

For patients with amaxillary transversal deficiency (MTD), various treatment options are available, partly based on the practitioner's experience. This study aimed to determine acut-off age for decision making between surgically assisted rapid palatal expansion (SARPE) over orthodontic rapid palatal expansion (ORPE) based on skeletal maturation in afemale population. A total of 100 cone beam computed tomography (CBCT) images of young females were analyzed on maturation of the pterygomaxillary (PMS), zygomaticomaxillary (ZMS), transpalatal (TPS), and midpalatal (MPS) sutures. Based on the maturation of these four junctions, four independent observers had to determine whether they would prefer ORPE or SARPE to widen the maxilla. For the PMS, the results show aclosure of 83-100% from 13to 17years. As for the TPS, aclosure of 78-85% was observed from 15years of age. For the 15- to 17-year-old females, aclosed ZMS was present in 32-47%. Regarding MPS, closed sutures presented in 61% (stagesD andE) of the 15-year-old females. The cut-off age at which SARPE was recommended was 15.1years for the orthodontist observers and 14.8years for the maxillofacial surgeon observers. Significant maturation of MPS was reached at the age of15 in afemale population. The PMS, TPS, MPS, and ZMS closed sequentially. Acomprehensive diagnostic approach is necessary for choosing the appropriate treatment. When in doubt, age could assist decision making in afemale population, with acut-off age of 15years in favor of SARPE based on this study.

Cross-Check QA: A Quality Assurance Workflow to Prevent Missed Diagnoses by Alerting Inadvertent Discordance Between the Radiologist and Artificial Intelligence in the Interpretation of High-Acuity CT Scans

PurposeThe aim of this study was to implement and evaluate a quality assurance (QA) workflow that leverages natural language processing to rapidly resolve inadvertent discordance between radiologists and an artificial intelligence (AI) decision support system (DSS) in the interpretation of high-acuity CT studies when the radiologist does not engage with AI DSS output. MethodsAll consecutive high-acuity adult CT examinations performed in a health system between March 1, 2020, and September 20, 2022, were interpreted alongside an AI DSS (Aidoc) for intracranial hemorrhage, cervical spine fracture, and pulmonary embolus. CT studies were flagged for this QA workflow if they met three criteria: (1) negative results by radiologist report, (2) a high probability of positive results by the AI DSS, and (3) unviewed AI DSS output. In these cases, an automated e-mail notification was sent to our quality team. If discordance was confirmed on secondary review—an initially missed diagnosis—addendum and communication documentation was performed. ResultsOf 111,674 high-acuity CT examinations interpreted alongside the AI DSS over this 2.5-year time period, the frequency of missed diagnoses (intracranial hemorrhage, pulmonary embolus, and cervical spine fracture) uncovered by this workflow was 0.02% (n = 26). Of 12,412 CT studies prioritized as depicting positive findings by the AI DSS, 0.4% (n = 46) were discordant, unengaged, and flagged for QA. Among these discordant cases, 57% (26 of 46) were determined to be true positives. Addendum and communication documentation was performed within 24 hours of the initial report signing in 85% of these cases. ConclusionsInadvertent discordance between radiologists and the AI DSS occurred in a small number of cases. This QA workflow leveraged natural language processing to rapidly detect, notify, and resolve these discrepancies and prevent potential missed diagnoses.

Dynamic CT Study on the Morphology and the Motor Ability of Unilateral Vocal Fold Paralysis

To investigate the morphological changes and motor functions of the larynx in unilateral vocal fold paralysis by using dynamic three-dimensional CT, and to explore the differences between vocal fold paralysis with different nerves involved. Twenty-five patients with unilateral vocal fold paralysis and 10 healthy subjects were selected as the paralytic group and the normal group, respectively. Tendynamic sequence images of laryngeal movement from inhalation to phonation were reviewed, and the glottic morphology at the coronal position, the minimum glottic area at the horizontal position, and the overall activity of the two groups were compared. The 25 patients with unilateral vocal fold paralysis were divided into the thyroarytenoid (TA)musclegroup, the TAand posterior cricoarytenoid (PCA) (TA+PCA) musclegroup, and the PCA musclegroup. The coronal and horizontal parameters of the three types were compared as noted above and the dynamic parameter changes were also compared between the groups. The height and thickness of bilateral vocal cords, the minimum glottic area, and the whole glottic activity were different in the paralysis group and were significantly different from those of the normal group (P<0.05). The value of the glottic gap ratio and its decrease rate in the TA+PCA group was smaller than those in the TA and PCA group, and the glottic gap ratio was the largest in the PCA group. Dynamic CT can provide a qualitative evaluation of laryngeal morphology and quantitative evaluation of motor function in vocal fold paralysis.

Burden and distribution of monosodium urate deposition in patients with hyperuricemia and gout: a cross-sectional Chinese population-based dual-energy CT study.

To investigate the distribution and burden of monosodium urate (MSU) deposition in hyperuricemia and gout patients with dual-energy computed tomography (DECT). A total of 1,936 consecutive patients from January 1, 2009, to September 15, 2017, underwent DECT examinations in Jinling Hospital. Of these, 1,294 patients were excluded due to other clinical diagnoses (n=1,041), inappropriate locations (n=82), poor-quality images (n=105), training cases (n=30) and duplicated data (n=36). Finally, 642 patients were included in this study. We retrospectively analyzed 1,127 DECT examinations in 642 consecutive patients (hyperuricemia group, n=121; gout group, n=521) and recorded the volume and number of MSU deposits. For each anatomical location, we recorded MSU deposition in the soft tissue and joint cavity. MSU deposition was analyzed and compared between groups. For normally distributed data, independent sample t-tests were used for comparison between the two groups. The independent samples nonparametric test was used to analyze nonnormally distributed data. (I) The burden of MSU deposition in the gout group {volume [0.14 (0.04-1.36)] and numbers [10.00 (5.00-19.00)]} was significantly higher than that {volume [0.08 (0.02-0.47), P=0.003] and numbers [9.50 (2.00-16.00), P=0.01]} in the hyperuricemia group. (II) The burden of MSU deposition in the knees {volume [0.24 (0.01-1.79), P=0.002] and quantity [6.00 (2.00-12.00), P=0.04]} and feet {volume [0.10 (0.04-0.66)] and number [9.00 (5.00-15.00)]} was significantly higher in the gout group than those {knees: the volume [0.03 (0.00-0.27), P=0.002] and the quantity [4.00 (0.00-9.00), P=0.04]; feet: the volume [0.07 (0.02-0.19), P=0.003)] and number [8.00 (2.25-12.00), P=0.04]} in the hyperuricemia group, respectively. (III) In the hyperuricemia group, the volume of MSU deposition was significantly higher in the soft tissues of the knee (0.022±0.042) and ankle (0.062±0.305) than in those (knee: 0.001±0.005, P=0.02; ankle: 0.027±0.234, P=0.02) in the joint cavity. Although subclinical urate deposition can occur in patients with asymptomatic hyperuricemia, the burden of urate deposition is greater in patients with symptomatic gout, and the distribution is more pronounced in the foot/knee. Thus, more effective patient management and monitoring can be achieved by measuring the burden of MSU deposits in the patient's feet/knees. These data suggest that a threshold for urate crystal volume at typical sites may be required before symptomatic disease develops.

A Rare Case of Ruptured Giant Adrenal Myelolipoma Presenting with Spontaneous Intre-Abdominal Haemorrahage: A Case Report

Adrenal myelolipoma is a rare benign neoplasm of mesenchymal origin composed of mature fatty tissue and bone marrow elements. It is a non-functioning benign tumor, usually asymptomatic and commonly detected incidentally during evaluation for unrelated symptoms; hence, it is usually referred to as an “incidentaloma”. Large myelolipomas can cause mass effects and vague abdominal pain, spontaneous tumor rupture with massive hemorrhage is a more dramatic manifestation, though, it is an uncommon entity. We report the case of a 41-year-old anemic male patient who underwent an abdominal CT study and a huge hemorrhagic adrenal myelolipoma was detected to reiterate the importance of recognizing the characteristic radiological features of myelolipoma to accurately diagnose these tumors and emphasize the inclusion of myelolipoma in the lists of differential diagnosis of causes of spontaneous intra-abdominal hemorrhages.

Misplaced Pterygoid Implant removed following Surgical Exploration

A 62-year-old male patient had reported to our department with a history of pterygoid implant placement in the right maxillary region. The referring dentist had updated us about the possibility of a misplaced implant. The patient was anxious but showed no clinical signs of discomfort or pain. A CT scan with contrast was done to check for the location of the implant and also visualize the proximity to any vital structures. The CT study revealed an implant seen in the right parapharyngeal space closely abutting the internal carotid artery. The screw of the implant was sharp and since it was closely abutting the internal carotid artery it warranted removal at the earliest. An endoscopic approach was discussed with the ENT surgeons but due to the size of the implant and limited access through the antrum we had to look for an alternative method. The technique of performing an access osteotomy of the maxilla would give better visualization and access to the implant but would require the maxilla to be plated and the patient who was 62 years old was not too keen on the thought of this procedure. Finally, an extraoral submandibular approach was finalized and used. Under general anaesthesia, a submandibular incision was marked and dissection was done, the carotid was first identified and taken control off in case we encountered any bleeding or injury to the internal maxillary artery while removing the implant. Dissection continued towards the mandible and the masseter was split to give access to the pterygoid region. An intraoperative C- arm showed that the implant was in close vicinity. The implant was removed intraorally via the buccal vestibule and the wound sites were closed without any complications.

Deep learning approach for differentiating indeterminate adrenal masses using CT imaging.

Distinguishing stage 1-2 adrenocortical carcinoma (ACC) and large, lipid poor adrenal adenoma (LPAA) via imaging is challenging due to overlapping imaging characteristics. This study investigated the ability of deep learning to distinguish ACC and LPAA on single time-point CT images. Retrospective cohort study from 1994 to 2022. Imaging studies of patients with adrenal masses who had available adequate CT studies and histology as the reference standard by method of adrenal biopsy and/or adrenalectomy were included as well as four patients with LPAA determined by stability or regression on follow-up imaging. Forty-eight (48) subjects with pathology-proven, stage 1-2 ACC and 43 subjects with adrenal adenoma >3 cm in size demonstrating a mean non-contrast CT attenuation >20 Hounsfield Units centrally were included. We used annotated single time-point contrast-enhanced CT images of these adrenal masses as input to a 3D Densenet121 model for classifying as ACC or LPAA with five-fold cross-validation. For each fold, two checkpoints were reported, highest accuracy with highest sensitivity (accuracy focused) and highest sensitivity with the highest accuracy (sensitivity focused). We trained a deep learning model (3D Densenet121) to predict ACC versus LPAA. The sensitivity-focused model achieved mean accuracy: 87.2% and mean sensitivity: 100%. The accuracy-focused model achieved mean accuracy: 91% and mean sensitivity: 96%. Deep learning demonstrates promising results distinguishing between ACC and large LPAA using single time-point CT images. Before being widely adopted in clinical practice, multicentric and external validation are needed.

Distribution, prevalence, and impact on the metatarsosesamoid complex of first metatarsal pronation in hallux valgus

BackgroundPrevious simulated weight-bearing CT (WBCT) studies classifying first metatarsal (M1) pronation suggested a high prevalence of M1 hyper-pronation in hallux valgus (HV). These findings have prompted a marked increase in M1 supination in HV surgical correction. No subsequent study confirms these M1 pronation values, and two recent WBCT investigations suggest lower normative M1 pronation values. The objectives of our WBCT study were to (1) determine M1 pronation distribution in HV, (2) define the hyperpronation prevalence compared to preexisting normative values, and (3) assess the relationship of M1 pronation to the metatarso-sesamoid complex. We hypothesized that the M1 head pronation distribution would be high in HV. MethodsWe retrospectively identified 88 consecutive feet with HV in our WBCT dataset and measured M1 pronation with the Metatarsal Pronation (MPA) and α angles. Similarly, using two previously published methods defining the pathologic pronation threshold, we assessed our cohort’s M1 hyper-pronation prevalence, specifically (1) the upper value of the 95% confidence interval (CI95) and (2) adding two standard deviations at the mean normative value (2 SD). Sesamoid station (grading) was assessed on the coronal plane. ResultsThe mean MPA was 11.4+/−7.4 degrees and the α angle was 16.2+/−7.4 degrees. According to the CI95 method, 69/88 HV (78.4%) were hyperpronated using the MPA, and 81/88 HV (92%) using the α angle. According to the 2 SD method, 17/88 HV (19.3%) were hyperpronated using the MPA, and 20/88 HV (22.7%) using the α angle. There was a significant difference in MPA among sesamoid gradings (p = 0.025), with a paradoxical decrease in MPA when metatarsosesamoid subluxation was increased. ConclusionM1 head pronation distribution in HV was higher than in normative values, but threshold change demonstrated contradictory hyper-pronation prevalences (85% to 20%), calling into question the previously reported high prevalence of M1 hyper-pronation in HV. An increase in sesamoid subluxation was associated with a paradoxical decrease in M1 head pronation in our study. We suggest that a greater understanding of the impact of HV M1 pronation is warranted before routine M1 surgical supination is recommended for patients with HV. Level of evidenceLevel III, retrospective cohort study.

The Role of &lt;sup&gt;68&lt;/sup&gt;Ga-DOTATATE PET/CT in the Follow-Up of Patients with Pancreatic Neuroendocrine Tumors: a Retrospective Study

Purpose: To study the impact of 68Ga-DOTATATE PET/CT on the treatment tactics of metastatic pancreatic neuroendocrine tumors (pNETs).Material and methods: 208 68Ga-DOTATATE PET/CTs enrolled in 50 patients. Each patient underwent 68Ga-DOTATATE PET/CT two to ten times (median 4.2Դ2.2). At the time of the first study, the diagnosis of pNET was confirmed histologically and immunohistochemically in all patients. CT and MRI, as well as assessment of biochemical recurrence (serotonin and chromogranin-A levels exceeding the reference intervals) performed in all patients within one month before the next PET/CT. The results of all the listed studies in the detection of recurrent metastatic pNETs compared.Results: At the first 68Ga-DOTATATE PET/CT, metastases were detected in 46 patients out of 50 (92 %). At the same time, prior to the first PET/CT, CT and MRI revealed tumor foci only in 34 patients (68 %). Thus, compared with routine imaging methods, additional tumor foci detected in 12 patients (24 %). Among all 208 PET/CT examinations, 166 results were positive (79.8 %). According to the results of all CT and MRI studies, tumor foci diagnosed in 117 cases (56.3 %). Compared to CT and MRI, additional tumor foci detected in 49 studies (23.6 %). Metastases on PET/CT detected in 43 studies, despite the absence of biochemical recurrence. On PET/CT, pNETs recurrence was detected in six patients versus three on CT and MRI. Tumor progression — in 10 patients versus five on CT and MRI.Conclusion: We revealed the influence of 68Ga-DOTATATE PET/CT on the management of patients in the absence of other signs of disease recurrence or progression. 68Ga-DOTATATE PET/CT in combination with CT and MRI contributes to earlier diagnosis of recurrent metastatic pNETs.

Trends in the incidence of pulmonary nodules in chest computed tomography: 10-year results from two Dutch hospitals

ObjectiveTo study trends in the incidence of reported pulmonary nodules and stage I lung cancer in chest CT.MethodsWe analyzed the trends in the incidence of detected pulmonary nodules and stage I lung cancer in chest CT scans in the period between 2008 and 2019. Imaging metadata and radiology reports from all chest CT studies were collected from two large Dutch hospitals. A natural language processing algorithm was developed to identify studies with any reported pulmonary nodule.ResultsBetween 2008 and 2019, a total of 74,803 patients underwent 166,688 chest CT examinations at both hospitals combined. During this period, the annual number of chest CT scans increased from 9955 scans in 6845 patients in 2008 to 20,476 scans in 13,286 patients in 2019. The proportion of patients in whom nodules (old or new) were reported increased from 38% (2595/6845) in 2008 to 50% (6654/13,286) in 2019. The proportion of patients in whom significant new nodules (≥ 5 mm) were reported increased from 9% (608/6954) in 2010 to 17% (1660/9883) in 2017. The number of patients with new nodules and corresponding stage I lung cancer diagnosis tripled and their proportion doubled, from 0.4% (26/6954) in 2010 to 0.8% (78/9883) in 2017.ConclusionThe identification of incidental pulmonary nodules in chest CT has steadily increased over the past decade and has been accompanied by more stage I lung cancer diagnoses.Clinical relevance statementThese findings stress the importance of identifying and efficiently managing incidental pulmonary nodules in routine clinical practice.Key Points• The number of patients who underwent chest CT examinations substantially increased over the past decade, as did the number of patients in whom pulmonary nodules were identified.• The increased use of chest CT and more frequently identified pulmonary nodules were associated with more stage I lung cancer diagnoses.

Regional differences in the level of inflammation between right and left sided coronary arteries: a cardiac CT study of epicardial fat attenuation index

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The CARDIOCOV project - Prototype for personalized assessment of cardiovascular risk and post-Covid myocarditis based on artificial intelligence, advanced medical imaging and cloud computing - financed by UEFISCDI PN-III-P2-2.1-PTE-2021-0450 (Contract Number 108PTE/2022). Background Pericoronary fat attenuation index is a novel CT-derived marker used to quantify vascular inflammation at the level of coronary vessels. It has prognostic value for major adverse cardiovascular events and provides improvements in cardiac risk assessment beside classical risk factors and coronary artery calcium score. However, the influence of local factors related to coronary circulation in the right versus left coronary bed, on the development of pericoronary inflammation, has not been elucidated so far. Purpose The aim of the study was to evaluate the regional differences in the level of inflammation between right and left sided coronary arteries. Methods In total, 153 patients (mean age 62 years, male patients 70.5%) who underwent clinically indicated coronary computed tomography angiography (CCTA) were included in the study. All the plaque features classically associated with vulnerability were evaluated for identification of high-risk plaques. Fat attenuation index (FAI) and the corresponding FAI score (which takes into consideration the risk factors and age) were calculated for all cases at the level of the left anterior descending artery (LAD), circumflex artery (Cx) and right coronary artery (RCA). Results A total of 459 coronary arteries were included in the analysis and both FAI and FAI score were higher at the level of RCA compared with LAD and Cx. FAI score was 15.23±11.97 at RCA vs 10.55±6.78 at LAD and 11.48±6.5 for Cx, p = 0.02. Also, a significantly higher value of FAI at the level of RCA was noted in comparison with the other two coronary arteries: −76±7.68 HU for RCA compared to −73.04±8.9 HU for LAD and −71.25±7.47 HU for Cx, p&amp;lt;0.0001. This difference was maintained in all the study sub-group analysis: for patients undergoing CT scan after COVID infection (−75.49±7.62 HU for RCA vs -72.89±9.40 HU for Cx and −71.28 ±7.82 HU for LAD, p = 0.01), or patients with high-risk plaques (20.98±16.29 for RCA vs 11.77±7.68 for Cx and 12.83±6.47 for LAD, p = 0.03). Conclusion Plaques located in different coronary territories exhibit different vulnerability patterns and different levels of inflammation. RCA seems to have a more pronounced susceptibility to inflammation, right coronary plaques exhibiting higher scores of inflammation in the territories surrounding coronary plaques.

#5095 THE CURIOUS CASE OF GAS IN THE GRAFT KIDNEY

Abstract Background and Aims Emphysematous pyelonephritis (EPN) denotes a severe infection of renal parenchyma resulting in necrosis and gas accumulation in the renal and perirenal tissue. Risk factors for urinary tract infections in renal transplant recipients include advanced age, female gender, reflux nephropathy prior to transplantation, diabetes mellitus, deceased donor kidney, kidney–pancreas transplant, retransplantation, antibody induction for immunosuppression, urinary bladder catheterisation, history of allograft rejection with subsequent escalation of immunosuppressive therapy and use of ureteral stents. There are no definite guidelines for management of EPN in renal allografts. If unstable and deteriorating, graft nephrectomy should be undertaken as soon as possible. Any delay in surgical intervention, be it percutaneous drainage or nephrectomy may result in death. Method A 25-year old male, diagnosed with IgA Nephropathy (IgAN) received a living donor renal transplant from his mother in 2013 after a dialysis vintage of 3 years. He received Basiliximab induction followed by maintenance immunosuppression with Tacrolimus, Mycophenolate mofetil and Prednisolone. He had no history of UTI in the immediate post-transplant period. His blood glucose levels were within normal limits and he had not had any urological intervention. In 2019, patient was diagnosed with IgAN recurrence as a cause of chronic renal allograft injury. His Creatinine at last follow up in July 2022 was 4.1 mg/dL. He presented in September 2022 with fever, chills, vomiting, pain in the right iliac fossa and inability to extend his right leg. At presentation, his BP was 86/60mmHg, with pyrexia and tachycardia. Ultrasonography revealed an ill-defined collection superomedial to the graft kidney with doubtful posterior extension and air foci. Non-contrast CT study revealed a large subcapsular collection, extending posteriorly into the right iliac fossa involving the right psoas major and inferiorly into the pelvis, with air foci and no evidence of any urinary tract obstruction suggestive of Acute Emphysematous pyelonephritis with ruptured abscess. He was started on broad-spectrum iv antibiotics- Meropenem and Levofloxacin. Immunosuppression was reduced. Laboratory investigations revealed total leucocyte count of 37,000 cells/mm3, Creatinine of 11 mg/dL, urine routine microscopy revealed field full of pus cells. Blood and urine cultures grew ESBL Escherichia coli. He was taken up for urgent urological intervention in the form of percutaneous drain insertion. Frank pus was aspirated and 200mL drained instantaneously, cultures of which demonstrated the same organism. Within 24 hours of pus drainage, patient became afebrile and had pain relief. He was given 3 weeks of culture-appropriate iv antibiotics, to continue another 3 weeks of oral Carbapenem. However, his graft dysfunction persisted, with no recovery and he became dialysis-dependent. Discussion EPN of the renal allograft is a rare occurrence. A study of EPN in renal transplant recipients by Alexander et al from 2012 revealed 18 out of 22 patients were diabetics, 9 necessitated graft nephrectomy and 7 required percutaneous drainage in addition to antibiotics4. Till date, up to 30 cases of graft EPN have been reported in English literature. The striking feature is that more than 90% of these cases were diabetic. Conclusion The complete pathogenesis of renal allograft EPN, especially in patients with no apparent traditionally described risk factors remains yet to be understood. A high degree of suspicion and early intervention may help to save the allograft.

CT and MRI of head and neck cutaneous lesions.

Cutaneous lesions are derived from the epidermis, dermis and cutaneous appendages. Whilst imaging may occasionally be performed to evaluate such lesions, they may be undiagnosed and demonstrated for the first time on head and neck imaging studies. Although usually amenable to clinical examination and biopsy, CT or MRI studies may also demonstrate characteristic imaging features which aid the radiological differential diagnosis. In addition, imaging studies define the extent and staging of malignant lesions, as well as the complications of benign lesions. It is important for the radiologist to understanding the clinical significance and associations of these cutaneous conditions. This pictorial review will describe and depict the imaging appearances of benign, malignant, overgrowth, blistering, appendage and syndromic cutaneous lesions. An increasing awareness of the imaging characteristics of cutaneous lesions and related conditions will help the framing of a clinically relevant report.

Toward automating RECIST 1.1: Improving AI new lesion detection with longitudinal image data.

e13545 Background: Automating RECIST 1.1 would offer benefits in speed, consistency, and cost of clinical trial imaging reads. Detection of new lesions is subjective and a common source of reader adjudication. Current AI lesion detection typically uses single timepoint images. The use of temporal data in AI is a rapidly evolving field in non-medical applications and new lesion detection in response assessment may benefit from longitudinal multi timepoint images. We explore the impact of longitudinal image input to deep neural networks for new lesion detection; as a proof of concept, we compare single vs dual timepoint input in new liver lesion detection in CT. Methods: We utilized CT images from two public datasets: 1) diseased liver (DL), a subset of DeepLesion (doi: 10.1117/1.JMI.5.3.036501), and 2) healthy liver (HL) from potential liver donors (Med Image Anal 69 (2021) 101950).. Due to the lack of a publicly available longitudinal image dataset with new lesions, we simulated (“sim”) a longitudinal study by registering HL scans (sim healthy baseline) with DL scans (sim follow up with new lesion) and selecting well-paired images using mutual information. From each pair of scans, we select one positive (with new lesion on follow up) and one negative (without lesion on follow up) 6x6cm image patch from within the liver, creating a dataset of 3296 patches with a balanced number of pos/neg samples. We trained two deep neural networks to classify the presence of a new liver lesion: 1) a conventional single timepoint model (ST) trained on DL patches only, i.e. using the follow up scan only, and 2) an experimental dual-timepoint model (DT) trained on patch pairs from DL-HL paired scans. We used 5-fold cross validation and paired t tests to compare model AUC and accuracy. Results: Of 10,594 CT studies (4,427 patients, pts) in DeepLesion, we paired 1648 DL scans (946 pts with liver lesions) with one of 20 registered HL scans (20 pts). The DT model outperformed the ST model, increasing AUC from 0.914 ± 0.002 to 0.929 ± 0.005 (p=0.040), with similar trends in accuracy (dataset split, Table 1). Conclusions: The DT model outperformed the ST model in the detection of new liver lesions, suggesting preliminary the benefit of multi-timepoint input to a deep neural network using sim longitudinal data. The use of longitudinal image data to improve interval change detection is a step towards automating radiologic response assessment in clinical trials. We plan to extend this work to automate new lesion detection in real clinical trial longitudinal images. Results (bold) are reported on test set across 5 folds. N image patches (ST) or patch pairs (DT). [Table: see text]

Impact of COVID-19 Infection on Regional Periocoronary Inflammation: An Angio-CT Study of Epicardial Fat Attenuation

Abstract Background It is currently well-known that inflammation plays an essential role in all phases of atherosclerosis. Recent CT studies showed that atherosclerotic plaques found in the right coronary arteries (RCA) display a greater number of features that increase their susceptibility to destabilization compared to plaques found in left coronary arteries (LCA). COVID-19’s impact on regional coronary inflammation is not well understood, despite extensive research on its effects on cardiovascular diseases. Objectives This study aimed to evaluate the regional differences between local inflammation at the level of left versus right coronary circulation in patients who had CCTA examinations for chest pain in the early stages after COVID-19 infection. Methods In total, 172 patients with chest pain and CCTA data available were included in the study, divided into two groups: Group 1 (n = 80) with recent COVID-19 infection, and Group 2 (n = 92) with no known COVID infection. Attenuation of epicardial fat density was calculated in all patients using the FAI technology available from Caristo (Oxford, UK), and the associated FAI score and CaRi Heart® score of related cardiovascular risk were calculated. Results CaRi Heart® Risk (p &lt; 0.0001) and Duke Score (p &lt; 0.0001) were significantly higher for the COVID-negative patients, who presented a significantly higher FAI score (p = 0.001). This difference was also present in all the three coronary arteries: LAD (p = 0.05), LCX (p = 0.05), RCA. In the COVID-19 positive group the FAI score was significantly higher at the RCA level (p = 0.0002), but the non-COVID-19 presented no significant differences of inflammation levels between the left and right coronary circulation. Conclusions COVID-19 infection is associated with a higher risk of inflammation in the pericoronary epicardial fat. In post- COVID-19 patients, this inflammation seems to be more pronounced at the level of the RCA, which indicates a potential role of local hemorheological factors in the complex process of inflammation-mediated plaque vulnerabilization after COVID.

Syndesmotic Malreduction Assessment Using Three-Dimensional Distance Mapping: A Cadaveric Weight Bearing CT Study

Syndesmotic Malreduction Assessment Using Three-Dimensional Distance Mapping: A Cadaveric Weight Bearing CT Study

Multi-slice spiral CT study on the anatomical variation of the left renal vein

Multi-slice spiral CT study on the anatomical variation of the left renal vein

Photon-counting versus Dual-Source CT of Congenital Heart Defects in Neonates and Infants: Initial Experience.

Background Photon-counting CT (PCCT) has been shown to improve cardiovascular CT imaging in adults. Data in neonates, infants, and young children under the age of 3 years are missing. Purpose To compare image quality and radiation dose of ultrahigh-pitch PCCT with that of ultrahigh-pitch dual-source CT (DSCT) in children suspected of having congenital heart defects. Materials and Methods This is a prospective analysis of existing clinical CT studies in children suspected of having congenital heart defects who underwent contrast-enhanced PCCT or DSCT in the heart and thoracic aorta between January 2019 and October 2022. CT dose index and dose-length product were used to calculate effective radiation dose. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated by standardized region-of-interest analysis. SNR and CNR dose ratios were calculated. Visual image quality was assessed by four independent readers on a five-point scale: 5, excellent or absent; 4, good or minimal; 3, moderate; 2, limited or substantial; and 1, poor or massive. Results Contrast-enhanced PCCT (n = 30) or DSCT (n = 84) was performed in 113 children (55 female and 58 male participants; median age, 66 days [IQR, 15-270]; median height, 56 cm [IQR, 52-67]; and median weight, 4.5 kg [IQR, 3.4-7.1]). A diagnostic image quality score of at least 3 was obtained in 29 of 30 (97%) with PCCT versus 65 of 84 (77%) with DSCT. Mean overall image quality ratings were higher for PCCT versus DSCT (4.17 vs 3.16, respectively; P < .001). SNR and CNR were higher for PCCT versus DSCT with SNR (46.3 ± 16.3 vs 29.9 ± 15.3, respectively; P = .007) and CNR (62.0 ± 50.3 vs 37.2 ± 20.8, respectively; P = .001). Mean effective radiation doses were similar for PCCT and DSCT (0.50 mSv vs 0.52 mSv; P = .47). Conclusion At a similar radiation dose, PCCT offers a higher SNR and CNR and thus better cardiovascular imaging quality than DSCT in children suspected of having cardiac heart defects. © RSNA, 2023.

Morphometric analysis of odontoid process among Arab population: a retrospective cone beam CT study.

This study aims to evaluate the feasibility of using cone beam computed tomography (CBCT) scans to assess the odontoid process diameter in the Arab population and to determine whether one or two cortical screws can be used for treating odontoid fractures. The odontoid process of 142 individuals aged 12-75 years, including 72 males (mean age: 35.5) and 70 females (mean age: 36.2), were analyzed using CBCT scans. The sagittal and coronal CBCT views were used to evaluate the antero-posterior (AP) and transverse diameters of the odontoid process. Males had substantially bigger transverse and AP diameters of the odontoid process than females (p<0.05 & P<0.01 respectively). Among the sample, 97 individuals (67.4%) had external transverse diameter (METD) of less than 9 mm which is slightly bigger than that of Indians and 48 individuals (31.83%) had enough room for two 3.5 mm or two 2.7 mm screws as their METD was more than 9 mm like that of Greek and Turkish. Age had no significant impact on the morphometric measurements of the odontoid process. More than sixty percent of the sample had METDs of less than 9 millimeters, indicating that a single 4.5-mm Herbert screw may be suggested for fixing fractured odontoid processes in the Arab population.

THE ROLE OF PET CT IN CANCER OF UNKNOWN PRIMARY

ABSTRACT:&#x0D; Objective: This study aimed to investigate the diagnostic value of positron emission tomography/computed tomography (PET/CT) in detecting the primary focus and in suspicious foci in patients who underwent PET/CT with a pre-diagnosis of carcinoma of unknown primary.&#x0D; Material and Methods: In this retrospective study, a total of 49 patients who underwent PET/CT scan with a prediagnosis of carcinoma of the unknown primary between 2015 and 2019, and whose clinical follow-up and histopathological data were available, were included.PET/CT study was performed in 20 (40%) patients after the metastatic lesion was detected as a result of pathology, and in 29 (60%) patients due to clinical findings and imaging methods and suspicion of malignancy. The histopathological and clinical evaluation of the patients before PET/CT and the primary surgery, histopathological examinations and clinical follow-ups after PET/CT were examined. The success of PET/CT in detecting primary lesions and evaluating suspicious lesions in metastatic cases was analyzed.&#x0D; Results: Seventeen (34.7%) of the patients were female and 32 (65.3%) were male. A primary malignant tumor was detected in 34 (85%) of 40 patients with PET/CT. Regional distribution in patients with primary cancer focus; 9 pancreases, 9 lungs, 4 livers, 3 urothelial, 2 thyroids, 1 vertebra, 1 breast, 1 ovary, 1 esophagus, 1 prostate, 1 iliac bone, 1 skin, 1 stomach and 1 colon. In the follow-up of 6 cases whose primary could not be determined; Cervical cancer was detected in 1, ovarian cancer in 1, and the primary focus could not be detected in the clinical follow-up of 4 metastatic patients.&#x0D; Conclusion: PET/CT is highly successful in detecting cancers whose primary is unknown. Therefore, PET/CT is a diagnostic imaging method for the detection of the primary in cancer patients whose primary is unknown.&#x0D; Keywords: Cancer of unknown primary; Positron emission tomography; Malignant lesion