CT Studies Research Articles

Effect of Dataset Size and Medical Image Modality on Convolutional Neural Network Model Performance for Automated Segmentation: A CT and MR Renal Tumor Imaging Study.

The aim of this study is to investigate the use of an exponential-plateau model to determine the required training dataset size that yields the maximum medical image segmentation performance. CT and MR images of patients with renal tumors acquired between 1997 and 2017 were retrospectively collected from our nephrectomy registry. Modality-based datasets of 50, 100, 150, 200, 250, and 300 images were assembled to train models with an 80-20 training-validation split evaluated against 50 randomly held out test set images. A third experiment using the KiTS21 dataset was also used to explore the effects of different model architectures. Exponential-plateau models were used to establish the relationship of dataset size to model generalizability performance. For segmenting non-neoplastic kidney regions on CT and MR imaging, our model yielded test Dice score plateaus of [Formula: see text] and [Formula: see text] with the number of training-validation images needed to reach the plateaus of 54 and 122, respectively. For segmenting CT and MR tumor regions, we modeled a test Dice score plateau of [Formula: see text] and [Formula: see text], with 125 and 389 training-validation images needed to reach the plateaus. For the KiTS21 dataset, the best Dice score plateaus for nn-UNet 2D and 3D architectures were [Formula: see text] and [Formula: see text] with number to reach performance plateau of 177 and 440. Our research validates that differing imaging modalities, target structures, and model architectures all affect the amount of training images required to reach a performance plateau. The modeling approach we developed will help future researchers determine for their experiments when additional training-validation images will likely not further improve model performance.

A Study on Ureteric Abnormalities in Single Contrast Bolus CT Urography at A Tertiary Care Centre

Introduction: CT urography is an imaging technique in which the i.v contrast is injected and phases of CT scan are taken to study the entire urinary system. It has essentially replaced intravenous urography (IVU) in most imaging practices. CT Urography has evolved as an ideal imaging tool for comprehensive imaging assessment of patients with flank pain, malignancies, hematuria, trauma, renal calculi, suspected congenital malformations and in various clinical settings. Other CT advantages include the use of multiplanar reconstruction (MPR), curved planar reformatted images, maximum intensity projection (MIP) and three-dimensional (3D) reconstruction which gives valuable information to the clinician about the extent of the lesions and helps in management.
 Aim: To study various types of ureteric abnormalities in CT Urography in various clinical presentation.
 Materials and methods: This is a tertiary hospital based observational Descriptive Cross sectional study conducted on 360 patients referred for CT Urography with Clinical Signs & Symptoms of urinary tract abnormalities, having ureteric imaging abnormalities. Siemens somatum High Definition 128 slice CT scanner was used for single bolus CT urography.
 Results: Males were more as compared to females with age group 31 to 50 years (44.4%). Abdominal pain with urinary complaints was seen in maximum number of patients (203 cases- 56.4%). Urinary complaints in known abdomino-pelvic malignancies was seen in 18% cases. 285 patients had obstructive urography findings like hydronephrosis or hydroureter, and 75 cases had non obstructive findings like ureteral filling defects due to calculi, clots, etc or abnormal ureteric course or only congenital abnormality. Most hydroureter cases were secondary to obstructive calculus followed by obstruction by external malignant mass.
 Conclusion: This study outlines the most common ureteric abnormalities in patients referred for CT urography which were mostly obstructive findings most cases were secondary to obstructive calculus followed by obstruction by external malignant mass. The non obstructive findings like ureteral filling defects were due to calculi, clots, etc or abnormal ureteric course or only congenital abnormalities. Delayed phase of CT urography can also be applied in Contrast CT study of abdomen & Pelvic scans on case to case basis to study ureteric involvements & pathologies.

Post-COVID syndrome or persistent COVID and depression

IntroductionSince the start of the COVID19 pandemic, numerous patients have exhibited symptoms related to the viral infection once the acute phase has resolved. The most frequent are fatigue or weakness, cognitive difficulties, insomnia, and anxiety or depression. It has been observed that the persistence of these symptoms is more common in cases of severe infections.ObjectivesWe expose a case that exemplifies it; A 60-year-old man suffering from severe COVID19 infection during 2021, with bilateral pneumonia and secondary pneumothorax. Three months after the acute episode, he continues to present related symptoms, such as dyspnea, asthenia, arthromyalgia, nausea, hyporexia, memory lapses, anxiety and depressive mood with apathy, anhedonia and suicidal ideas.MethodsThe patient starts follow-up in Mental Health and antidepressant treatment with Vortioxetine 10mg. In the following months he presented significant improvement consisting in decrease of the asthenia, dyspnea, arthromyalgia and especially in anxious symptoms and depressive mood, disappearing the apathy, anhedonia and suicidal ideation. However, the persistence of memory failures draws attention, which remain in a similar degree or with slight subjective improvement.The exploration and complementary test were the following: -Chest CT: Hydropneumothorax, parenchymal infiltrates, alveolar consolidations, left lamellar pneumothorax.-Head CT, complete analysis, microbiological and cytological studies without relevant resolution.-Assessment by the Rehabilitation and Neurology service.ResultsThis case exposes the existence of a post-COVID syndrome, where the symptoms related to the infection persist, including anxious-depressive symptoms of moderate-severe intensity. The different diagnoses that were considered were the following: Post-COVID syndrome, Adjustment disorder with mixed anxious-depressive symptomatology, Depressive episode.ConclusionsWe consider that in this case and in others that are similar, which are increasingly common in routine clinical practice, the etiopathogenesis of the syndrome is of interest. We found that it is difficult to discern the origin of the symptoms, not being able to differentiate an adaptive difficulty to the infection situation (added to the COVID pandemic context), versus a more organic affectation that improves when receiving pharmacological treatment, as in this case with antidepressants.Disclosure of InterestNone Declared

Primary adrenal leiomyosarcoma

Primary adrenal leiomyosarcoma is a very rare mesenchymal tumor that arises from smooth muscle cells in the wall of the central adrenal vein or its branches (1). Less than 50 cases have been published in the English literature (2). The tumors are aggressive and often metastasize. This report describes a case of primary adrenal leiomyosarcoma that presented as intermittent left flank pain of 6 months duration in an otherwise healthy 58-year-old Caucasian female. The patient was initially imaged with an abdominal ultrasound, which revealed a left suprarenal mass. A follow-up CT of the abdomen and pelvis confirmed a malignant appearing left adrenal mass. A subsequent PET-CT demonstrated increased metabolic activity within the adrenal mass without evidence of metastasis. Biopsy proven metastasis eventually was detected on surveillance CT studies over the course of 2.5 years. Since this is such a rare malignancy, documenting its imaging findings with multiple modalities is of importance to add to the medical literature and help further characterize its imaging features.

Pleural appendages: Description, incidence and relations with body mass index

Background and aimsPleural appendages (PA) are portions of extrapleural fat that hang from the chest wall. They have been described on videothoracoscopy, however their appearance, frequency and possible relationship with the amount of patient's fat remain unknown. Our aim is to describe their appearances and prevalence on CT, and determinate whether their size and number is higher in obese patients. Patients and methodsAxial images of 226 patients with pneumothorax on CT chest were retrospectively reviewed. Exclusion criteria included known pleural disease, previous thoracic surgery and small pneumothorax.Patients were divided in obese (BMI>30) and non-obese (BMI<30) groups. Presence, position, size and number of PA were recorded. Chi square and Fisher's exact test were used to evaluate differences between the two groups, considering p<0.05 as significant. ResultsValid CT studies were available for 101 patients. Extrapleural fat was identified in 50 (49.5%) patients. Most were solitary (n=31). Most were located in the cardiophrenic angle (n=27), and most measured <5cm (n=39).There was no significant difference between obese and non-obese patients regarding the presence or absence of PA (p=0.315), number (p=0.458) and size (p=0.458). ConclusionsPleural appendages were seen in 49.5% patients with pneumothorax on CT. There was no significant difference between obese and non-obese patients regarding presence, number and size of pleural appendages.

Lung ultrasonography versus chest CT for assessing peripheric pulmonary lesions in hemorrhagic fever with renal syndrome: a prospective comparative study in China.

To compare the performances of lung ultrasonography (LUS) versus chest CT for assessing peripheric pulmonary lesions in hemorrhagic fever with renal syndrome (HFRS). Paired LUS and chest CT scan were prospectively performed and compared when in diagnosing five pathologies including region with alveolar-interstitial pattern (RAIP), alveolar-interstitial syndrome (AIS), lung consolidation, pleural effusion (PE), and pericardial effusion, in each patient with HFRS. Forty-four patients (aged 39.9 ± 15.0years, 35 males) were included, from which 68 paired LUS and chest CT imaging data of 816 lung regions were obtained and analyzed. Compared with chest CT, LUS showed high sensitivity (92.19-100%) and negative predictive value (95.9-100%), but relatively low specificity (39.47-97.21%) and positive predictive value (37.5-76.47%) for diagnosing the above pathologies. McNemer's test showed LUS detected more positive findings than chest CT (all p ≤ 0.002). There was a strong correlation between LUS and chest CT scores (rs = 0.7141, p < 0.0001) and both scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS patients. LUS was comparable with chest CT for diagnosing peripheric pulmonary lesions and clinical assessment in patients with HFRS. Given the high sensitivity and negative predictive value compared with chest CT, LUS can be used as an excellent rule-out tool in HFRS, while its use in rule-in still requires more evidence. Considering the obvious advantages of LUS being a bedside, less expansive, and non-radiating exam, future multi-center randomized LUS versus chest CT studies may help to guide the preferred method. • LUS could detect more positive findings than chest CT in assessing peripheric pulmonary lesions in patients with hemorrhagic fever with renal syndrome (HFRS). • Compared with chest CT, LUS showed high sensitivity but relatively low specificity when diagnosing the peripheric pulmonary lesions caused by HFRS. • Both LUS and chest CT scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS.

Large-scale transient peri-ictal perfusion magnetic resonance imaging abnormalities detected by quantitative image analysis.

Epileptic seizures require a rapid and safe diagnosis to minimize the time from onset to adequate treatment. Some epileptic seizures can be diagnosed clinically with the respective expertise. For more subtle seizures, imaging is mandatory to rule out treatable structural lesions and potentially life-threatening conditions. MRI perfusion abnormalities associated with epileptic seizures have been reported in CT and MRI studies. However, the interpretation of transient peri-ictal MRI abnormalities is routinely based on qualitative visual analysis and therefore reader dependent. In this retrospective study, we investigated the diagnostic yield of visual analysis of perfusion MRI during ictal and postictal states based on comparative expert ratings in 51 patients. We further propose an automated semi-quantitative method for perfusion analysis to determine perfusion abnormalities observed during ictal and postictal MRI using dynamic susceptibility contrast MRI, which we validated on a subcohort of 27 patients. The semi-quantitative method provides a parcellation of 3D T1-weighted images into 32 standardized cortical regions of interests and subcortical grey matter structures based on a recently proposed method, direct cortical thickness estimation using deep learning-based anatomy segmentation and cortex parcellation for brain anatomy segmentation. Standard perfusion maps from a Food and Drug Administration-approved image analysis tool (Olea Sphere 3.0) were co-registered and investigated for region-wise differences between ictal and postictal states. These results were compared against the visual analysis of two readers experienced in functional image analysis in epilepsy. In the ictal group, cortical hyperperfusion was present in 17/18 patients (94% sensitivity), whereas in the postictal cohort, cortical hypoperfusion was present only in 9/33 (27%) patients while 24/33 (73%) showed normal perfusion. The (semi-)quantitative dynamic susceptibility contrast MRI perfusion analysis indicated increased thalamic perfusion in the ictal cohort and hypoperfusion in the postictal cohort. Visual ratings between expert readers performed well on the patient level, but visual rating agreement was low for analysis of subregions of the brain. The asymmetry of the automated image analysis correlated significantly with the visual consensus ratings of both readers. We conclude that expert analysis of dynamic susceptibility contrast MRI effectively discriminates ictal versus postictal perfusion patterns. Automated perfusion evaluation revealed favourable interpretability and correlated well with the classification of the visual ratings. It may therefore be employed for high-throughput, large-scale perfusion analysis in extended cohorts, especially for research questions with limited expert rater capacity.

Unreported incidental pulmonary embolism in patients with cancer: Radiologic natural history and risk of recurrent venous thromboembolism and death

PurposeTo assess the risk of recurrent venous thromboembolism (VTE) and death in patients with unreported cancer-associated incidental pulmonary embolism (iPE). Materials and methodsMatched cohort study on cancer patients with a CT study including the chest between 2014-01-01 and 2019-06-30. Studies were reviewed for unreported iPE, and cases were matched with controls without iPE. Cases and controls were followed for one year, with recurrent VTE and death as outcome events. ResultsOf the included 2960 patients, 171 patients had unreported and untreated iPE. While controls had a one-year VTE risk of 8.2 events per 100 person-years, cases with a single subsegmental iPE had a recurrent VTE risk of 20.9 events, and between 52.0 and 72.0 events per 100 person-years for multiple subsegmental iPE and more proximal iPE. In multivariable analysis, multiple subsegmental and more proximal iPE were significantly associated with the risk of recurrent VTE, while single subsegmental iPE was not associated with the risk of recurrent VTE (p = 0.13). In the subgroup of patients (n = 47) with cancer not in the highest Khorana VTE risk category, no metastases and up to three involved vessels, recurrent VTE occurred in two patients (4.7 cases per 100 person-years). There were no significant associations between iPE burden and risk of death. ConclusionIn cancer patients with unreported iPE, iPE burden was associated with the risk of recurrent VTE. However, having a single subsegmental iPE was not associated with the risk of recurrent VTE. There were no significant associations between iPE burden and risk of death.

Maisonneuve ankle fracture.

Maisonneuve fracture (MF) is defined as an ankle fracture-dislocation associated always with a fracture of the proximal quarter of the fibula and rupture of the anterior and interosseous tibiofibular ligaments. Other injuries are variable. Recent CT studies have demonstrated that MF is a far more complex injury than initially supposed. Therefore it is necessary to change substantially the current concepts related to this issue. MF is combined in about 80% of cases with a fracture of the posterior malleolus and also with malposition of the distal fibula in the fibular notch. An exact assessment of these injuries requires post-injury CT examination which should be used as a standard in MFs. The main goal of treatment is anatomical reduction of the distal fibula into the fibular notch. In case of avulsion of a larger fragment of the posterior malleolus, it is necessary to perform as the first step its reduction and fixation from the posterolateral approach and thus restore integrity of the notch. Closed reduction of the distal fibula is associated with malposition in up to 50% of cases and therefore open reduction from a short anterolateral approach is preferred. Accuracy of reduction should be always checked by postoperative CT scan.

Recent Developments on Understanding Charge Transfer in Molecular Electron Donor‐Acceptor Systems

AbstractCharge transfer (CT) in molecular electron donor‐acceptor systems is pivotal for artificial photosynthesis, photocatalysis, photovoltaics and fundamental photochemistry. We summarized the recent development in study of CT and discussed its application in thermally activated delayed fluorescence (TADF) emitters. The direct experimental proof of the spin multiplicity of the charge separated (CS) state with pulsed laser excited time‐resolved electron paramagnetic resonance (TREPR) spectroscopy was discussed. Experimental determination of the electron exchange energy (J) of the CS state, with magnetic field effect on its yield or lifetime was introduced. The electron spin transfer accompanying the CT, studied with pulsed EPR spectra was briefly discussed. Tuning of the CT yield and kinetics with selective vibration excitation of the linker (the bridge) with IR pulse was presented. Above all, these studies show that there are more fun than simply monitoring the formation of the cations and anions and the kinetics or CS yields in this area.

CNN-based evaluation of bone density improves diagnostic performance to detect osteopenia and osteoporosis in patients with non-contrast chest CT examinations

PurposeAs osteoporosis is still underdiagnosed by clinicians and radiologists, the aim of the present study was to assess the performance of an Artificial intelligence (AI)-based Convolutional Neuronal Network (CNN)-Algorithm for the detection of low bone density on routine non-contrast chest CT in comparison to clinical reports using DEXA scans as reference. MethodThis retrospective cross-sectional study included patients who underwent non-contrast chest CT and DEXA between April 2018 and June 2018 (n = 109, 19 men, mean age: 67.7 years). CT studies were evaluated for thoracic vertebral bone pathologies using a CNN-Algorithm, which calculates the attenuation profile of the spine. The content of the radiological reports was evaluated for the description of osteoporosis or osteopenia. DEXA was used as the reference standard. To estimate correlation the Spearman test was used and the comparison of the different groups was performed using the Wilcoxon rank sum test. Diagnostic was evaluated by performing a receiver operating characteristic curve analysis. ResultsThe DEXA examination revealed normal bone density in 42 patients, while 49 patients had osteopenia and 7 osteoporosis. There was a statistically significant correlation between the mean CNN-based attenuation of the thoracic spine and the bone density measured on the DEXA in the hip (r = 0.51, p < 0.001) and lumbar spine (r = 0.34, p = 0.01). The mean attenuation was significantly higher in patients with normal bone density (172 ± 44.5 HU) compared to those with osteopenia or osteoporosis (125.2 ± 33.8 HU), (p < 0.0001). Diagnostic performance in distinguishing normal from abnormal bone density was higher using the CNN-based vertebral attenuation (accuracy 0.75, sensitivity: 0.93, specificity: 0.61) compared to clinical reports (accuracy 0.51, sensitivity: 0.14, specificity: 0.53). ConclusionCNN-based evaluation of bone density may provide additional value over standard clinical reports for the detection of osteopenia and osteoporosis in patients undergoing routine non-contrast chest CT scans. This additional value could improve identification of fracture risk and subsequent treatment.

Association of CA19-9 and tumor size in treatment monitoring for patients with metastatic pancreatic ductal adenocarcinoma (PDAC).

693 Background: Although modern cancer treatment has significantly prolonged patient’s life, it comes with a high financial cost. Based on an NIH report on Financial Burden of Cancer Care, treating PDAC costs $108K, $18K, and $125K for initial treatment, during follow up, and in last year of life, respectively. Of these, CA19-9 and CT studies are obtained concurrently to evaluate tumor burden whose cost can be reduced by decreasing imaging frequency when CA19-9 remains stable. As a pilot study, we evaluated whether changes in CA19-9, an inexpensive laboratory study commonly used for monitoring treatment response, correlates with tumor size change on imaging studies. A positive correlation may lead us to design future studies to evaluate whether stable CA19-9 can serve as an indicator for stable disease on CT scan such that imaging frequency (and cost) may be reduced. Methods: We retrospectively identified PDAC patients from our tumor registry from 2016 to 2019. Subjects were included if they met the following criteria: 1) diagnosed with PDAC 2) had at least 2+ CA19-9 and CT/MR follow up assessments with the laboratory and imaging studies within one month of each other, and 3) had measurable lesions as defined by RECIST 1.1 criteria. Due to limited resources, we limited the maximum number of lesions to 4 instead of the usual 5 for RECIST 1.1. Two-dimensional orthogonal tumor sizes were measured on axial images with the largest cross-section. Changes in the values were obtained serially (from the immediately prior study). Nonparametric correlations (Spearman’s rho) were used to evaluate monotonicity. The significance level was set at p &lt; 0.05. Results: We screened 300 subjects from the tumor registry and identified 23 subjects suitable for our study. 13 subjects were female and 10 were male with ages ranging from 35 to 84. We identified 55 target lesions and 128 assessments (with both CA19-9 and imaging) from the 23 subjects. We analyzed the log absolute and log relative change in CA19-9 with change in tumor area. When absolute CA19-9 value, absolute change in CA19-9, and relative change in CA19-9 were tested against the absolute change in tumor size, the correlation was significant for the absolute value and absolute change of CA19-9 (p &lt; 0.01), but not for relative change of CA19-9 (p &lt; 0.11). When tested against relative change in tumor size, all three values were highly significant (p &lt; 0.001). Conclusions: Our finding of direct correlations between changes of CA19-9 and relative change of tumor size on imaging suggests that CA19-9 can serve as a surrogate measure of relative change of tumor burden for patients undergoing treatment. This provides motivation for future studies evaluating the possibility that stable CA19-9 can represent stable tumor burden such that expensive imaging studies may be obtained at longer time intervals to reduce financial cost to patients.

The 23rd Gunma CT and MRI Study Group

The 23rd Gunma CT and MRI Study Group

Thoracic CT incidental pulmonary bullae in dogs: Characterization, interobserver variability, and general anesthesia risks.

Ruptures of pulmonary blebs and bullae are the most common cause of spontaneous pneumothorax in dogs. Incidental bullae/blebs have been documented in otherwise healthy people, however information for veterinary patients is currently lacking. Objectives of this retrospective, observer agreement, analytical study were to characterize incidental bullae in thoracic CT studies of dogs, assess interobserver variability for characterizing the bullae, and assess anesthesia risks. Inclusion criteria were dogs presenting for non-pneumothorax related reasons that had a thoracic CT at a single specialty and emergency hospital from 2012 to 2021 and had a bulla listed in the CT report. Medical records for dogs meeting inclusion criteria were reviewed to collect data on signalment, weight, total number of general anesthesia procedures 2 years prior and 2 years following the CT scan, and adverse anesthesia events. In addition, the CT images were reviewed by three American College of Veterinary Radiology-certified veterinary radiologists to collect data on the location, size, number of bullae and thickness of the bulla wall. A total of 1119 dogs met initial inclusion criteria and 74 dogs were included in analyses. There was no sex predilection for incidental pulmonary bullae. Bullae were more commonly found in older (median age 11.3 years), large breed dogs (median weight 20.7kg). A solitary bulla of less than 1cm was the most common finding with no apparent predilection for a particular lung lobe. There was strong correlation among the three radiologists for bulla location, size, and number, but weak correlations for bulla wall thickness. No adverse anesthesia events were found following CT anesthesia or following repetitive anesthesia procedures.

Intramural dissection of the esophagus is a rare complication of eosinophilic esophagitis in children

Eosinophilic esophagitis (EoE) is characterized by endoscopic signs and detection of more than 15 eosinophils per high-power field of view in biopsy specimens of the esophageal mucosa. Due to deep chronic eosinophilic inflammation, it can cause complications: esophageal stenosis, rarely perforation. Intramural esophageal dissection (IED) is a previously undescribed complication of EoE in children. We present a case of IED in a 15-year-old boy, which clinically manifested itself as sudden epigastric pain radiating to the back and nausea against the background of acute respiratory viral infection. According to endoscopy, CT and X-ray contrast study, a double-barreled esophagus with two cavities was detected - the esophagus itself and a blind "pocket", histologically in which granulation tissue and active inflammation with a large number of neutrophils were found. The initial histological examination did not reveal significant eosinophilic infiltration in the esophagus. The boy received a course of esomeprazole and was re-examined 6 months later. The radiographic picture was the same, and endoscopic examination revealed characteristic signs of EoE: longitudinal grooves and erosions, transverse rings, and narrowing of the esophageal lumen. In the middle third, the picture of a double-barreled esophagus was still preserved, but without signs of acute detachment, but with a dense septum between the two cavities of the esophagus. Histologically, the infiltrate contained more than 50 eosinophils in the field of view. The diagnosis was eosinophilic esophagitis complicated by RTI. A strict hypoallergenic diet was prescribed, excluding obligate allergens, budesonide 1 mg 2 times a day in the form of a gel. Endoscopic dissection of the esophageal septum was performed, its patency was restored. After 2 months, the boy was examined again while continuing drug therapy and diet. He had no complaints, radiologically the patency of the esophagus was not impaired. Endoscopically, the esophagus was freely passable, there was only a small fold at the site of the operation, longitudinal grooves and small erosions in the lower third remained. Histologically, the number of eosinophils decreased significantly. Therapy was continued. This clinical case demonstrates the possibility of developing RDI as a complication of EoE. The course of EoE can be asymptomatic, and RDI is the first manifestation of the disease. The endoscopic picture of a double-barreled esophagus is a consequence of dissection. The combination of a hypoallergenic diet, topical steroids and endoscopic septectomy is effective in the treatment of EoE with RDI.

Detection of pancreatic cancer with two- and three-dimensional radiomic analysis in a nationwide population-based real-world dataset

BackgroundCT is the major detection tool for pancreatic cancer (PC). However, approximately 40% of PCs < 2 cm are missed on CT, underscoring a pressing need for tools to supplement radiologist interpretation.MethodsContrast-enhanced CT studies of 546 patients with pancreatic adenocarcinoma diagnosed by histology/cytology between January 2005 and December 2019 and 733 CT studies of controls with normal pancreas obtained between the same period in a tertiary referral center were retrospectively collected for developing an automatic end-to-end computer-aided detection (CAD) tool for PC using two-dimensional (2D) and three-dimensional (3D) radiomic analysis with machine learning. The CAD tool was tested in a nationwide dataset comprising 1,477 CT studies (671 PCs, 806 controls) obtained from institutions throughout Taiwan.ResultsThe CAD tool achieved 0.918 (95% CI, 0.895–0.938) sensitivity and 0.822 (95% CI, 0.794–0.848) specificity in differentiating between studies with and without PC (area under curve 0.947, 95% CI, 0.936–0.958), with 0.707 (95% CI, 0.602–0.797) sensitivity for tumors < 2 cm. The positive and negative likelihood ratios of PC were 5.17 (95% CI, 4.45–6.01) and 0.10 (95% CI, 0.08–0.13), respectively. Where high specificity is needed, using 2D and 3D analyses in series yielded 0.952 (95% CI, 0.934–0.965) specificity with a sensitivity of 0.742 (95% CI, 0.707–0.775), whereas using 2D and 3D analyses in parallel to maximize sensitivity yielded 0.915 (95% CI, 0.891–0.935) sensitivity at a specificity of 0.791 (95% CI, 0.762–0.819).ConclusionsThe high accuracy and robustness of the CAD tool supported its potential for enhancing the detection of PC.

Assessment of glenoid version on MRI and CT with partial scapular inclusion

BackgroundPrevious studies evaluating the reproducibility of glenoid version measurement rely on the medial border of the scapula. Despite this common protocol, there are little data demonstrating the necessity of the full scapular body. The purpose of this study was to evaluate the reproducibility of glenoid version measurement using CT and MRI with and without visualization of the medial border of the scapula. MethodsPatients were retrospectively identified with both preoperative CT and MRI studies before planned shoulder arthroplasty surgery. Exclusion criteria included patients with studies lacking an axial view and CT studies that did not include the medial border of the scapula. A single image was captured for each study. One copy of the CT images was then made with the medial border of the scapula digitally subtracted, leaving 4 cm of the scapular body in view. A survey was created using full CT images, corresponding CT images with 4 cm of the scapular body and MRI images (with 4 cm of the scapular body) for ten shoulder and elbow surgeons to provide glenoid version measurements. Participants remeasured the glenoid version in all the images after the first measurement to allow for intraobserver reliability. Variation was compared within each category. Interobserver and intraobserver reliability (ICC: intraclass correlation coefficient) were determined using weighted intraclass correlation coefficient values for glenoid version measurements. ResultsA total of 68 patients were available for analysis. The 68 patients then had 204 corresponding images (Full CT, 4 cm CT & MRI). The mean glenoid version for the full CT images, the 4 cm CT, and the 4 cm MRI were −12.0° (±8.4°), −15.2 (±8.1), & −13.6° (±8.2°) respectively. These were statistically different (P < .001). The inter-rater reliability demonstrated moderate agreement (ICC = 0.692-0.709) for the CT, the 4 cm CT (ICC = 0.554-0.580) and MRI (ICC = 0.664-0.715). Intra-rater reliability had excellent agreement (ICC = 0.933) for the CT and good agreement for the 4 cm CT (ICC = 0.841) and MRI (ICC = 0.861). ConclusionAlthough the MRI demonstrated significantly greater retroversion compared with the full CT, this was not considered to be clinically significant (>3°) whereas a truncated CT may provide less accurate version measurements. All imaging modalities yielded moderate agreement when evaluated by shoulder surgeons. Based on the results of this study, it appears accurate to measure glenoid version on MRI, even when the entire scapula is not well visualized.

Can triphasic hepatic multislice CT validate the LI-RADS treatment response algorithm after trans-catheter arterial chemoembolization treatment of hepatocellular carcinoma?

BackgroundOur aim is to evaluate LI-RADS-TR algorithm and its ability to assess the viability of TACE-treated HCC. We prospectively evaluated 100 patients with known HCC, treated with TACE and came for follow-up to assess therapy response and to plan the next step in treatment using triphasic CT study. Imaging response was evaluated according to LI-RADS-TR algorithm and compared to modified Response Evaluation Criteria in Solid Tumors (mRECIST) arterial phase hyperenhancement (APHE) criterion. Reference standard for “viable” tumors in treated observations included presence of strong tumor hyperenhancement in arterial phase and washout in the delayed phase which also shows dense accumulation of iodized oil in the target lesion.ResultsWhen equivocal observations were considered as LR-TR viable, LR-TR viable resulted in 92.31% sensitivity, 83.33% specificity and 88% accuracy. On the other side when equivocal observations were considered as LR-TR nonviable, it resulted in 84.62% while the specificity increased to 100% with increased accuracy (92%). The mRECIST criteria for viable tumors (presence of APHE) showed sensitivity of 84.62% and specificity of 75%. mRECIST and LR-TR sensitivities were the same when equivocal lesions were considered as nonviable and lower mRECIST than LR-TR when equivocal lesions were considered as viable, while specificities were higher in LR-TR viable being 100% when equivocal lesions were considered as nonviable, 83.33% when equivocal lesions were considered as viable and 75% in mRECIST-viable.ConclusionsLR-TR algorithm showed good diagnostic performance compared to mRECIST, with high specificity and sensitivity when equivocal lesions were considered as nonviable, as well as improved accuracy.

CT and MRI as Diagnostic and Management Decision Tools for First Time Lateral Patellar Dislocations: A Cross-Sectional, Retrospective Study.

Following first-time lateral patellar dislocation (FTLPD), most patients are treated conservatively, although 50% of patients will have recurrent dislocations. Typically, radiographs followed by CT and/or MRI are used to assist the clinician in determining treatment strategy and, combined with clinical findings, intraarticular free bodies (CT/MRI), significant medial patellofemoral ligament (MPFL) tear (MRI) and lateral displacement of the patella (CT) form relative indications for surgery. Radiographs, MRI and CT knee studies of 34 patients after lateral patellar dislocation (26 FTLPD) were evaluated for intraarticular free bodies, patellar/trochlear fracture, lateral femoral condyle compression, MPFL tear, tibial tuberosity-trochlear groove (TT-TG) distance, and surgery indications. Free bodies and fractures were also evaluated on knee radiographs. FTLPD was analyzed as a subgroup. Surgical indications were compared between imaging modalities. Among FTLPD (26 patients); free bodies were identified in 13 and 19 patients using MRI and CT respectively, compared with 5 patients on radiographs; this was statistically significant. In 8 cases surgery was indicated based on MPFL tear (MRI) combined with lateral patellar displacement (CT). When MRI and CT results were combined, 21 of 26 patients had imaging indications for surgery compared to 13 and 19 patients based on the MRI or CT alone, respectively.CT was statistically better than MRI alone or MRI with radiographs in identifying patients requiring surgery. An MRI or CT study is warranted to determine the need for surgery. A second imaging study (different from the first) should be considered, if surgical indication was not established from the initial study or clinical presentation.

Prevalence and radiologic features of elastofibroma dorsi: a CT study

Prevalence and radiologic features of elastofibroma dorsi: a CT study