Whole-body CT Scan Research Articles

“All-in-one” window/level whole-body computed tomography scan – A faster way to evaluate trauma cases

PurposeTo investigate the accuracy and total assessment time (TAT) of the “All-in-one” (AIO)-window/level setting for whole-body computed tomography (CT) image compared to multiple tissue-specific window/level settings conventionally used for detection of traumatic injuries. MethodContrast-enhanced chest, abdomen, and pelvic CT scans of 50 patients who presented to our emergency department (ED) for major trauma were retrospectively selected. In a simulation of a “wet read” performed at the CT scanner console, 6 readers with different levels of experience had up to 3 min to describe any traumatic finding identified on the CTs. The readers reviewed each patient in two different sessions separated by a washout period to suppress any recall bias from one session to the next. Each scan was reviewed once using the AIO-window/level setting and another time using the conventional bone, lung, and soft tissue window/level display settings, in a randomized order. The CT reports were used as reference standard. ResultsOverall, there was no statistically significant difference in the assessment accuracy of the review based on the AIO or the conventional window/level settings (0.89 ± 0.09 vs 0.90 ± 0.08). Using the AIO-window/level settings, TAT was 14.3 s faster when compared with the conventional window/level settings (2.33 ± 0.63 vs 2.57 ± 0.51 min; p < 0.001). ConclusionsIn a time-delimited image review, similar diagnostic accuracy was reached faster using the AIO vs the conventional window/level settings. When providing a “wet read” at the CT console, the ability to identify traumatic injury using a single AIO-window/level may help expedite patient management.

Photon-counting Detector CT with Deep Learning Noise Reduction to Detect Multiple Myeloma.

Background Photon-counting detector (PCD) CT and deep learning noise reduction may improve spatial resolution at lower radiation doses compared with energy-integrating detector (EID) CT. Purpose To demonstrate the diagnostic impact of improved spatial resolution in whole-body low-dose CT scans for viewing multiple myeloma by using PCD CT with deep learning denoising compared with conventional EID CT. Materials and Methods Between April and July 2021, adult participants who underwent a whole-body EID CT scan were prospectively enrolled and scanned with a PCD CT system in ultra-high-resolution mode at matched radiation dose (8 mSv for an average adult) at an academic medical center. EID CT and PCD CT images were reconstructed with Br44 and Br64 kernels at 2-mm section thickness. PCD CT images were also reconstructed with Br44 and Br76 kernels at 0.6-mm section thickness. The thinner PCD CT images were denoised by using a convolutional neural network. Image quality was objectively quantified in two phantoms and a randomly selected subset of participants (10 participants; median age, 63.5 years; five men). Two radiologists scored PCD CT images relative to EID CT by using a five-point Likert scale to detect findings reflecting multiple myeloma. The scoring for the matched reconstruction series was blinded to scanner type. Reader-averaged scores were tested with the null hypothesis of equivalent visualization between EID and PCD. Results Twenty-seven participants (median age, 68 years; IQR, 61-72 years; 16 men) were included. The blinded assessment of 2-mm images demonstrated improvement in viewing lytic lesions, intramedullary lesions, fatty metamorphosis, and pathologic fractures for PCD CT versus EID CT (P < .05 for all comparisons). The 0.6-mm PCD CT images with convolutional neural network denoising also demonstrated improvement in viewing all four pathologic abnormalities and detected one or more lytic lesions in 21 of 27 participants compared with the 2-mm EID CT images (P < .001). Conclusion Ultra-high-resolution photon-counting detector CT improved the visibility of multiple myeloma lesions relative to energy-integrating detector CT. © RSNA, 2022 Online supplemental material is available for this article.

A deep learning algorithm for detecting lytic bone lesions of multiple myeloma on CT.

Whole-body low-dose CT is the recommended initial imaging modality to evaluate bone destruction as a result of multiple myeloma. Accurate interpretation of these scans to detect small lytic bone lesions is time intensive. A functional deep learning) algorithm to detect lytic lesions on CTs could improve the value of these CTs for myeloma imaging. Our objectives were to develop a DL algorithm and determine its performance at detecting lytic lesions of multiple myeloma. Axial slices (2-mm section thickness) from whole-body low-dose CT scans of subjects with biochemically confirmed plasma cell dyscrasias were included in the study. Data were split into train and test sets at the patient level targeting a 90%/10% split. Two musculoskeletal radiologists annotated lytic lesions on the images with bounding boxes. Subsequently, we developed a two-step deep learning model comprising bone segmentation followed by lesion detection. Unet and "You Look Only Once" (YOLO) models were used as bone segmentation and lesion detection algorithms, respectively. Diagnostic performance was determined using the area under the receiver operating characteristic curve (AUROC). Forty whole-body low-dose CTs from 40 subjects yielded 2193 image slices. A total of 5640 lytic lesions were annotated. The two-step model achieved a sensitivity of 91.6% and a specificity of 84.6%. Lesion detection AUROC was 90.4%. We developed a deep learning model that detects lytic bone lesions of multiple myeloma on whole-body low-dose CTs with high performance. External validation is required prior to widespread adoption in clinical practice.

Bone segmentation in contrast enhanced whole-body computed tomography

Segmentation of bone regions allows for enhanced diagnostics, disease characterisation and treatment monitoring in CT imaging. In contrast enhanced whole-body scans accurate automatic segmentation is particularly difficult as low dose whole body protocols reduce image quality and make contrast enhanced regions more difficult to separate when relying on differences in pixel intensities. This paper outlines a U-net architecture with novel preprocessing techniques, based on the windowing of training data and the modification of sigmoid activation threshold selection to successfully segment bone-bone marrow regions from low dose contrast enhanced whole-body CT scans. The proposed method achieved mean Dice coefficients of 0.979 ± 0.02, 0.965 ± 0.03, and 0.934 ± 0.06 on two internal datasets and one external test dataset respectively. We have demonstrated that appropriate preprocessing is important for differentiating between bone and contrast dye, and that excellent results can be achieved with limited data.

Estimating 3-D whole-body composition from a chest CT scan.

Estimating whole-body composition from limited region-computed tomography (CT) scans has many potential applications in clinical medicine; however, it is challenging. To investigate if whole-body composition based on several tissue types (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT], intermuscular adipose tissue [IMAT], skeletal muscle [SM], and bone) can be reliably estimated from a chest CT scan only. A cohort of 97 lung cancer subjects who underwent both chest CT scans and whole-body positron emission tomography-CT scans at our institution were collected. We used our in-house software to automatically segment and quantify VAT, SAT, IMAT, SM, and bone on the CT images. The field-of-views of the chest CT scans and the whole-body CT scans were standardized, namely, from vertebra T1 to L1 and from C1 to the bottom of the pelvis, respectively. Multivariate linear regression was used to develop the computer models for estimating the volumes of whole-body tissues from chest CT scans. Subject demographics (e.g., gender and age) and lung volume were included in the modeling analysis. Ten-fold cross-validation was used to validate the performance of the prediction models. Mean absolute difference (MAD) and R-squared (R2 ) were used as the performance metrics to assess the model performance. The R2 values when estimating volumes of whole-body SAT, VAT, IMAT, total fat, SM, and bone from the regular chest CT scans were 0.901, 0.929, 0.900, 0.933, 0.928, and 0.918, respectively. The corresponding MADs (percentage difference) were 1.44±1.21L (12.21%±11.70%), 0.63±0.49L (29.68%±61.99%), 0.12±0.09L (16.20%±18.42%), 1.65±1.40L (10.43%±10.79%), 0.71±0.68L (5.14%±4.75%), and 0.17±0.15L (4.32%±3.38%), respectively. Our algorithm shows promise in its ability to estimate whole-body compositions from chest CT scans. Body composition measures based on chest CT scans are more accurate than those based on vertebra third lumbar.

Structured Reporting of Whole-Body Trauma CT Scans: Friend, not Foe

Structured Reporting of Whole-Body Trauma CT Scans: Friend, not Foe

Emergency whole-body CT scans in pediatric patients with trauma: patterns of injuries, yield of dual-phase scanning, and influence of second read on detection of injuries.

To describe injury patterns in children with multiple trauma (MT), evaluate the yield of dual-phase whole-body CT (WBCT), and quantify missed injuries detected on second reading. Remotely analyzed WBCT performed between 2011 and 2020 in 63 emergency departments on children admitted for MT were included. Second reading occurred within 24 h. Collected data included age, sex, mechanism, Injury Severity Score (ISS), radiologists' experience, time and duration of first reading, conclusion of both readings, and dosimetry. Melvin score assessed the clinical impact of missed injuries. Overall, 1114 patients were included, 1982 injuries were described in 662 patients (59.4%), 452/1114 (40.6%) WBCT were negative, and 314 (28.2%) patients had MT (≥ 2 body parts injured). The most frequent injuries were pulmonary contusions (8.3%), costal fractures (6.2%), and Magerl A1 vertebral fractures (4.9%). Overall, 151 injuries were missed in 92 (8.3%) patients. Independent predictors for missed injuries were age ≤ 4 years (p = 0.03), number of injured body parts ≥ 2 (p = 0.01), and number of injuries ≥ 3 (p < 0.001). Melvin score grade 3 lesions were found in 16/92 (17.4%) patients with missed injuries (1.4% of all WBCT), where only prolonged follow-up was necessary. Thirteen active bleeding or pseudoaneurysms were detected (0.7% of injuries). Injuries were diagnosed in 59.4% of patients. Double-reading depicted additional injuries in 8.3% of patients, significantly more in children ≤ 4 years, with ≥ 3 injuries or ≥ 2 injured body parts. As 28 % of patients had MT and 1.1% had active extravasation or pseudoaneurysm, indication for WBCT should be carefully weighted. • When performed as a first-line imaging evaluation, approximately 41% of WBCT for MT children were considered normal. • The three most common injuries were pulmonary contusions, costal fractures, and Magerl A1 vertebral fractures, but the patterns of traumatic injuries on WBCT depended on the children's age and the trauma mechanism. • The independent predictors of missed injuries were age ≤ 4 years, number of body parts involved ≥ 2, and total number of injuries ≥ 3.

Automated segmentation of whole-body CT images for body composition analysis in pediatric patients using a deep neural network.

To develop an automatic segmentation algorithm using a deep neural network with transfer learning applicable to whole-body PET-CT images in children. For model development, we utilized transfer learning with a pre-trained model based on adult patients. We used CT images of 31 pediatric patients under 19 years of age (mean age, 9.6 years) who underwent PET-CT from institution #1 for transfer learning. Two radiologists manually labeled the skin, bone, muscle, abdominal visceral fat, subcutaneous fat, internal organs, and central nervous system in each CT slice and used these as references. For external validation, we collected 14 pediatric PET/CT scans from institution #2 (mean age, 9.1 years). The Dice similarity coefficients (DSCs), sensitivities, and precision were compared between the algorithms before and after transfer learning. In addition, we evaluated segmentation performance according to sex, age (≤ 8 vs. > 8 years), and body mass index (BMI, ≤ 20 vs. > 20 kg/m2). The algorithm after transfer learning showed better performance than the algorithm before transfer learning for all body compositions (p < 0.001). The average DSC, sensitivity, and precision of each algorithm before and after transfer learning were 98.23% and 99.28%, 98.16% and 99.28%, and 98.29% and 99.28%, respectively. The segmentation performance of the algorithm was generally not affected by age, sex, or BMI, except for precision in the body muscle compartment. The developed model with transfer learning enabled accurate and fully automated segmentation of multiple tissues on whole-body CT scans in children. • We utilized transfer learning with a pre-trained segmentation algorithm for adult to develop an algorithm for automated segmentation of pediatric whole-body CT. • This algorithm showed excellent performance and was not affected by sex, age, or body mass index, except for precision in body muscle.

Diagnostic value of chest radiography in the early management of severely injured patients with mediastinal vascular injury

IntroductionTime is of the essence in the management of severely injured patients. This is especially true in patients with mediastinal vascular injury (MVI). This rare, yet life threatening injury needs early detection and immediate decision making. According to the ATLS guidelines [American College of Surgeon Committee on Trauma in Advanced Trauma Life Support (ATLS®), 10th edn, 2018], chest radiography (CXR) is one of the first-line imaging examinations in the Trauma Resuscitation Unit (TRU), especially in patients with MVI. Yet thorough interpretation and the competence of identifying pathological findings are essential for accurate diagnosis and drawing appropriate conclusion for further management. The present study evaluates the role of CXR in detecting MVI in the early management of severely injured patients.MethodWe addressed the question in two ways. (1) We performed a retrospective, observational, single-center study and included all primary blunt trauma patients over a period of 2 years that had been admitted to the TRU of a Level-I Trauma Center. Mediastinal/chest (M/C) ratio measurements were calculated from CXRs at three different levels of the mediastinum to identify MVI. Two groups were built: with MVI (VThx) and without MVI (control). The accuracy of the CXR findings were compared with the results of whole-body computed tomography scans (WBCT). (2) We performed another retrospective study and evaluated the usage of sonography, CXR and WBCT over 15 years (2005–2019) in level-I–III Trauma Centers in Germany as documented in the TraumaRegister DGU® (TR-DGU).ResultsStudy I showed that in 2 years 267 patients suffered from a significant blunt thoracic trauma (AIS ≥ 3) and met the inclusion criteria. 27 (10%) of them suffered MVI (VThx). Through the initial CXR in a supine position, MVI was detected in 56–92.6% at aortic arch level and in 44.4–100% at valve level, depending on different M/C-ratios (2.0–3.0). The specificity at different thresholds of M/C ratio was 63.3–2.9% at aortic arch level and 52.9–0.4% at valve level. The ROC curve showed a statistically random process. No significant differences of the cardiac silhouette were observed between VThx and Control (mean cardiac width was 136.5 mm, p = 0.44). Study II included 251,095 patients from the TR-DGU. A continuous reduction of the usage of CXR in the TRU could be observed from 75% in 2005 to 25% in 2019. WBCT usage increased from 35% in 2005 to 80% in 2019. This development was observed in all trauma centers independently from their designated level of care.ConclusionAccording to the TRU management guidelines (American College of Surgeon Committee on Trauma in Advanced Trauma Life Support (ATLS®), 10th edn, 2018; Reissig and Kroegel in Eur J Radiol 53:463–470, 2005) CXR in supine position is performed to detect pneumothorax, hemothorax and MVI. Our study showed that sensitivity and specificity of CXR in detecting MVI was statistically and clinically not reliable. Previous studies have already shown that CXR is inferior to sonography in detecting pneumothorax and hemothorax. Therefore, we challenge the guidelines and suggest that the use of CXR in the early management of severely injured patients should be individualized. If sonography and WBCT are available and reasonable, CXR is unnecessary and time consuming. The clinical reality reflected in the usage of CXR and WBCT over time, as documented in the TR-DGU, seems to support our statement.

Audit of Motor Vehicle Accidents at a Trauma Center.

BackgroundMotor vehicle accidents (MVAs) are the leading cause of accidental deaths in India. An audit of trauma cases is required in order to improve hospital policy and patient care, as well as to change the attitude and perspective of healthcare staff.MethodsA retrospective observational study was performed on MVA trauma victims admitted to a tertiary trauma care center. Parameters included mean age with range, gender distribution, length of hospital stay (LOS), anatomical location of injuries, and the percentage of age groups and number of patients undergoing a nonoperative approach versus those with exploration and intervention. The correlation of body mass index (BMI) and co-morbidities with trauma, whole-body CT scan (WBCT) versus selective scanning, readmissions and revisits, and blood transfusion requirements were studied.ResultsThe majority of patients were young male adults and females having a higher LOS than males. Prolonged hospitalization is linked to a higher risk of complications and a higher expense. Individuals who suffered severe injuries recovered more slowly 12 months after the accident. The majority of patients had a brief hospitalization. Sixty-two point three (62.3) percent of patients suffered a head injury, with men accounting for the majority. Men were worst-affected, necessitating surgery. Obesity and BMI, regardless of gender, are not associated with trauma outcomes. Our studies found no link between co-morbidities and length of stay in MVA patients. Although the majority of patients did not require surgery, 28.8% required a blood transfusion. Our research found no link between BMI and injury severity score (ISS).ConclusionObese people sustaining MVAs had the same injured body regions as patients who were normal weight. They had a lower ISS than normal-weight individuals but a lengthier in-hospital stay.

Usefulness and outcome of whole-body computed tomography (pan-scan) in trauma patients: A prospective study

BackgroundSevere trauma can cause multi-organ injuries, and the mortality rate may increase if significant organ injuries are missed. This study was performed to determine whether whole-body computed tomography scan (pan-scan) can detect significant injury and leads to proper management, including alteration the priority of management. MethodsThis prospective study was conducted from January 2019 to March 2021 and involved trauma patients level 1, level 2, and dangerous mechanism of trauma. Additionally, the data of trauma patients who had selective computed tomography scan were retrospectively reviewed to compared the clinical benefits. ResultsTwenty-two patients were enrolled in the prospective study. The pan-scan detected significant organ injury in 86% of the patients. Prioritization of organ injury management changed after performance of the pan-scan in 64% (major change in 64.29% and minor change in 35.71%). Skull base fracture, small bowel injury, retroperitoneal injury, kidney and bladder injury, and occult pneumothorax were the majority of injuries which was not consider before underwent pan-scan (p < 0.05). The door-to-scan time tended to be shorter in the pan-scan group than in the selective scan group without a significant difference [mean (SD), 59.5 (34) and 72.0 (86) min, respectively; p = 0.13]. Pan-scan contribute 100% confidence for trauma surgeon in diagnosis of specific organ injuries in severe injured patients. ConclusionsThe pan-scan facilitates timely detection of significant unexpected organ injuries such as the skull base, occult pneumothorax, small bowel, and retroperitoneum. It also helps to prioritize management and increases the diagnostic confidence of trauma surgeons, leading to better outcomes without delay.

Real-time estimation of patient-specific dose distributions for medical CT using the deep dose estimation.

With the rising number of computed tomography (CT) examinations and the trend toward personalized medicine, patient-specific dose estimates are becoming more and more important in CT imaging. However, current approaches are often too slow or too inaccurate to be applied routinely. Therefore, we propose the so-called deep dose estimation (DDE) to provide highly accurate patient dose distributions in real time METHODS: To combine accuracy and computational performance, the DDE algorithm uses a deep convolutional neural network to predict patient dose distributions. To do so, a U-net like architecture is trained to reproduce Monte Carlo simulations from a two-channel input consisting of a CT reconstruction and a first-order dose estimate. Here, the corresponding training data were generated using CT simulations based on 45 whole-body patient scans. For each patient, simulations were performed for different anatomies (pelvis, abdomen, thorax, head), different tube voltages (80kV, 100kV, 120kV), different scan trajectories (circle, spiral), and with and without bowtie filtration and tube current modulation. Similar simulations were performed using a second set of eight whole-body CT scans from the Visual Concept Extraction Challenge in Radiology (Visceral) project to generate testing data. Finally, the DDE algorithm was evaluated with respect to the generalization to different scan parameters and the accuracy of organ dose and effective dose estimates based on an external organsegmentation. DDE dose distributions were quantified in terms of the mean absolute percentage error (MAPE) and a gamma analysis with respect to the ground truth Monte Carlo simulation. Both measures indicate that DDE generalizes well to different scan parameters and different anatomical regions with a maximum MAPE of 6.3% and a minimum gamma passing rate of 91%. Evaluating the organ dose values for all organs listed in the International Commission on Radiological Protection (ICRP) recommendation, shows an average error of 3.1% and maximum error of 7.2% (bone surface). The DDE algorithm provides an efficient approach to determine highly accurate dose distributions. Being able to process a whole-body CT scan in about 1.5s, it provides a valuable alternative to Monte Carlo simulations on a graphics processing unit (GPU). Here, the main advantage of DDE is that it can be used on top of any existing Monte Carlo code such that real-time performance can be achieved without major adjustments. Thus, DDE opens up new options not only for dosimetry but also for scan and protocoloptimization.

POEMS Syndrome: a clinical challenge / Síndrome de POEMS: um desafio clínico

A 42-year-old male patient admitted to our service with a history of progressive and symmetrical weakness, paresthesia of the lower limbs, weight loss and urinary retention for about 8 months. Physical examination demonstrated poor general condition, lower limb edema, hepatomegaly and digital clubbing. Neurological examination showed a polyneuropathic pattern, with hypoesthesia and absence of deep reflexes of the lower limbs. Initial laboratory investigation demonstrated erythrocytosis and thyroid and adrenal dysfunction in addition to hypergammaglobulinemia. CSF analysis, due to the clinical suspicion of chronic inflammatory demyelinating polyneuropathy, resulted in protein-cytological dissociation. PIDC was hypothesized to be due to light-chain disease, but for this association we supplemented with bone marrow analysis and whole-body CT scan, which showed 4% atypia in plasma cells and osteolytic and osteoblastic lesions in the vertebro-costal region between the 8th and 9th vertebrae. Subsequent biopsy confirmed plasmacytoma. He performed autologous bone marrow transplantation, but evolved with infectious complications and died within 3 months.

Improving the protocol for whole-body CT scans in trauma patients.

While whole-body computed tomography is an established diagnostic method for the work up of polytraumatized patients, the protocols used differ between trauma centers. This study aimed to compare scan duration and estimated radiation of two protocols. Secondary aim was to assess if using the revised CT protocol reduced the number of additional images of the upper extremities. Two groups of consecutive trauma patients, which both received a whole-body CT, were analyzed. Patients, who received a three-phased CT during which their arms needed to be repositioned from their side to above the head, were assigned to group A. Those, who received a CT with their arms placed on a pillow ventral to the abdomen throughout the entire scan were assigned to group B. Estimated radiation dose, scan duration, number of upper limb injuries and number of additional images of the upper limbs within 24h after initial CT were assessed. Group A consisted of 182 patients, group B of 218. The scan duration was 3min shorter (p < 0.001) and the estimated radiation dose lower (15.0 vs 22.9mSv, p < 0.001) in group B. There was no difference in the number of upper limb injuries detected or the number of upper limb additional images required within 24h. Using a whole-body CT scan protocol in which the arms remain on a pillow ventral to the torso instead of one which requires a repositioning of the arms, both scan duration and estimated radiation dose can be reduced. Despite the arms being within the scanned area in the revised protocol, the number of additional imaging of the upper extremities could not be reduced.

Osteochondrosis and other lesions in all intervertebral, articular process and rib joints from occiput to sacrum in pigs with poor back conformation, and relationship to juvenile kyphosis

BackgroundComputed tomography (CT) is used to evaluate body composition and limb osteochondrosis in selection of breeding boars. Pigs also develop heritably predisposed abnormal curvature of the spine including juvenile kyphosis. It has been suggested that osteochondrosis-like changes cause vertebral wedging and kyphosis, both of which are identifiable by CT. The aim of the current study was to examine the spine from occiput to sacrum to map changes and evaluate relationships, especially whether osteochondrosis caused juvenile kyphosis, in which case CT could be used in selection against it. Whole-body CT scans were collected retrospectively from 37 Landrace or Duroc boars with poor back conformation scores. Spine curvature and vertebral shape were evaluated, and all inter-vertebral, articular process and rib joints from the occiput to the sacrum were assessed for osteochondrosis and other lesions.ResultsTwenty-seven of the 37 (73%) pigs had normal spine curvature, whereas 10/37 (27%) pigs had abnormal curvature and all of them had wedge vertebrae. The 37 pigs had 875 focal lesions in articular process and rib joints, 98.5% of which represented stages of osteochondrosis. Five of the 37 pigs had focal lesions in other parts of vertebrae, mainly consisting of vertebral body osteochondrosis. The 10 pigs with abnormal curvature had 21 wedge vertebrae, comprising 10 vertebrae without focal lesions, six ventral wedge vertebrae with ventral osteochondrosis lesions and five dorsal wedge vertebrae with lesions in the neuro-central synchondrosis, articular process or rib joints.ConclusionsComputed tomography was suited for identification of wedge vertebrae, and kyphosis was due to ventral wedge vertebrae compatible with heritably predisposed vertebral body osteochondrosis. Articular process and rib joint osteochondrosis may represent incidental findings in wedge vertebrae. The role of the neuro-central synchondrosis in the pathogenesis of vertebral wedging warrants further investigation.

A Model for Nano-Scale Spherical Surface Coverage and Protein Corona Formation By Amyloidogenic Peptides

The conformation of three amyloidogenic peptides; amyloid beta 1–40 (Aβ1−40), alpha synuclein (α-syn), and beta-2-microglobulin (β2m) are closely associated with the process of causing neurodegenerative diseases. Use of a peptide adsorbed gold nano-particle system allowed us to investigate the interactive segment of each peptide responsible for peptide-peptide networking, which is crucial to initiate the formation of an oligomer and leads to fibrillogenesis. The adsorption orientationof theamyloidogenic peptides onthe nano-goldcolloid spherical surface wasexplainedbysimulatinghowmuchareaofthemetalsurfacewascoveredbythepeptides,i.e.,coverageratio,Θ. The empirically extracted Θ was explained by the summation of the 1st layer and the 2nd layer with a spikingout orientation of the prolate. Of note, the involvement of the 2nd layer was peptide type dependent. The nanosize dependence of Θ was linearly correlated with available spacing between adjacent peptides, Sd, which were approximated as prolates, For Aβ1−40 and α-syn, the 2nd layer was more included as Sd increased. In contrast, β2m was found to gyrate over the gold surface as Sd increased, creating a partially positive (δ+) region and repelling the extra β2m from the surface. Thus, as Sd decreased, it prohibited the gyration of β2m resulting in less δ+ region, and more β2m monomers were adsorbed with δ+ segment as the 2nd layer than the case where β2m gyrates more under relatively larger Sd. Based on the trend found in an experimentally extracted Θ as a function of Sd, optimized charge distribution of Aβ1−40 and α-syn were concluded to be negative partial charge (δ−) region that was covered by the positive partial charge (δ+) region. However, β2m may have a relatively large and/or distributed δ+ region with a small portion of δ− at the one end of a prolate. The characterization made in this work confirmed current understandings on the formation of the protein corona over nano-particles.

Major trauma with only dynamic criteria: is the routine use of whole-body CT as a first level examination justified?

Risks and benefits of systematic use of whole-body CT (WBCT) in patients with major trauma when no injury is clinically suspected is still subject of controversy. WBCT allows early identification of potentially evolving lesions, but exposes patients to the risk of high radiation dose and iodine contrast agent. The study aimed to assess if WBCT could be avoided in trauma patients with negative clinical examination. This retrospective study included polytrauma patients admitted to the Emergency Department in a six-month period, who had undergone a WBCT scan for major dynamic criteria, with hemodynamic stability, absence of clinical and medical risk factors for major trauma. The patients (n = 233) were divided into two groups according to the absence (n = 152) or presence (n = 81) of clinical suspicion of organ injury. The WBCT results were classified as negative, positive for minor and positive for major lesions. The average patient age was 44years. CT scans were completely negative in 111 (47.6%) patients, whose 104 (93.7%) were in the negative clinic group. 122 (52.4%) CT scans were positive, 69 (56.6%) for minor lesions and 53 (43.4%) for major lesions. Among the 48 (39.3%) positive CT scans in patients with negative clinic, only 5 (10.4%) were positive for major lesions. We found a significant difference in the frequency of injuries between the clinically negative and clinically positive patient groups (p < 0.001). A thorough clinical examination associated with a primary radiological evaluation may represent a valid diagnostic approach for trauma with only major dynamic criteria to limit the use of WBCT.

Ultra-Low-Dose Whole-Body Computed Tomography Protocol Optimization for Patients With Plasma Cell Disorders: Diagnostic Accuracy and Effective Dose Analysis From a Reference Center.

BackgroundThe whole-body low-dose CT (WBLDCT) is the first-choice imaging technique in patients with suspected plasma cell disorder to assess the presence of osteolytic lesions. We investigated the performances of an optimized protocol, evaluating diagnostic accuracy and effective patient dose reduction using a latest generation scanner.Methods and MaterialsRetrospective study on 212 patients with plasma cell disorders performed on a 256-row CT scanner. First, WBLDCT examinations were performed using a reference protocol with acquisition parameters obtained from literature. A phantom study was performed for protocol optimization for subsequent exams to minimize dose while maintaining optimal diagnostic accuracy. Images were analyzed by three readers to evaluate image quality and to detect lesions. Effective doses (E) were evaluated for each patient considering the patient dimensions and the tube current modulation.ResultsA similar, very good image quality was observed for both protocols by all readers with a good agreement at repeated measures ANOVA test (p>0.05). An excellent inter-rater agreement for lesion detection was achieved obtaining high values of Fleiss’ kappa for all the districts considered (p<0.001). The optimized protocol resulted in a 56% reduction of median DLP (151) mGycm, interquartile range (IQR) 128–188 mGycm vs. 345 mGycm, IQR 302–408 mGycm), of 60% of CTDIvol (2.2 mGy, IQR 1.9–2.7 mGy vs. 0.9 mGy, IQR 0.8–1.2 mGy). The median E value was about 2.6 mSv (IQR 1.7–3.5 mSv) for standard protocol and about 1.5 mSv (IQR 1.4–1.7 mSv) for the optimized one. Dose reduction was statistically significant with p<0.001.ConclusionsProtocol optimization makes ultra-low-dose WBLDCT feasible on latest generation CT scanners for patients with plasma cell disorders with effective doses inferior to conventional skeletal survey while maintaining excellent image quality and diagnostic accuracy. Dose reduction is crucial in such patients, as they are likely to undergo multiple whole-body CT scans during follow-up.

The Effect of Fat Distribution on the Inflammatory Response of Multiple Trauma Patients-A Retrospective Study.

Objectives In recent years; increasing evidence pointed out the clinical importance of adipose tissue (AT) distribution in various patient populations. In particular, visceral adipose tissue (VAT), when compared to subcutaneous adipose tissue (SAT), was found to play a pivotal role in the development of inflammatory reaction. The aim of the present study was to examine whether body fat distribution has an impact on the development of systemic inflammatory response syndrome (SIRS) in patients with polytrauma. Methods In our retrospective study; we filtered our institution records of the German Trauma Registry (Trauma Register DGU) from November 2018 to April 2021 and included 132 adult polytrauma patients with injury severity score (ISS) >16. Subsequently; we measured the visceral and subcutaneous adipose tissue area based on whole-body CT scan and calculated the ratio of VAT to SAT (VSr). Thereafter, the patient population was evenly divided into three groups; respectively VSr value less than 0.4 for the first group (low ratio), 0.4–0.84 for the second group (intermediate ratio), and greater than 0.84 for the third group (high ratio). Considering the other influencing factors; the groups were further divided into subgroups in the respective analysis according to gender (male/female), BMI (<25 or ≥25), and ISS (<26 or ≥26). Result VSr was an independent factor from body mass index (BMI) (r2 = 0.003; p = 0.553). VSr in male patients was significantly higher (p < 0.001). Patients with low VSr had higher ISS scores (p = 0.028). Polytrauma patients with higher VSr tended to have lower SIRS scores and significant differences of SIRS score were found on multiple days during the whole hospitalization period. In the low VAT/SAT group, male patients, and patients with BMI greater than 25, both exhibited higher SIRS scores during hospital stay (day 16: p = 0.01; day 22: p = 0.048 and p = 0.011; respectively). During hospitalization, patients with higher ISS score (≥26) in the low VSr group was found to have higher SIRS score (day 16; p = 0.007). Over the hospital stay; serum markers of CRP; CK; and leukocyte in patients with low VSr were higher than those in patients in the intermediate and high VSr groups; with significant difference discovered on multiple days (day 16: 0.014; day 22: p = 0.048). Conclusion Lower VSr is associated with increased inflammatory response and worse clinical outcome in patients with polytrauma. Furthermore; VSr is an independent factor providing additional information to BMI.

Median 10 years follow-up of patients with covert Cushing\u2019s syndrome: a case series

BackgroundEctopic adrenocorticotropic hormone secretion syndrome occurs in 10% of all patients with adrenocorticotropic-hormone-dependent hypercortisolism. It is usually associated with overt malignancies or with occult and indolent tumors. This study aims to confirm the source of ectopic adrenocorticotropic hormone in four patients with ectopic Cushing’s syndrome over time.Case presentationA 38-year-old Iranian man with Cushing’s syndrome underwent bilateral adrenalectomy since the source of ectopic adrenocorticotropic hormone secretion was not localized and pituitary imaging was normal. A whole-body scan revealed a right-lung tumoral mass with mediastinal lymph node metastasis. The mass was assumed a lung carcinoid tumor with mediastinal adenopathy. Right-lung mid-zone lobectomy and mediastinal lymphadenectomy were done. In a 47-year-old Iranian man with Cushing’s syndrome, whole-body computed tomography scan revealed a pulmonary nodule in the posterior segment of the left lower lobe of the lung. The third case was a 25-year-old Iranian man who presented with symptoms and signs of Cushing’s syndrome. Pituitary magnetic resonance imaging revealed a microadenoma 5 × 9 mm. Whole-body scan showed abnormal focal somatostatin receptors analog avid lesion in the posterior aspect of inferior third of right lung, highly suggestive of ectopic adrenocorticotropic-hormone-producing tumor. The last case was a 43-year-old Iranian woman with Marfan syndrome with a history of mitral and aortic valve replacement and chronic dissection of the aorta, who presented with symptoms and signs of Cushing’s syndrome. She underwent bilateral adrenalectomy 1 year later owing to failure to locate ectopic adrenocorticotropic hormone syndrome. Whole-body scan showed abnormally increased radiotracer uptake in the midline of the skull base and posterior aspect of the middle zone of left hemithorax and bed of left lobe of thyroid.ConclusionThe clinical spectrum of ectopic adrenocorticotropic hormone secretion syndrome is wide, and distinguishing Cushing’s disease from ectopic adrenocorticotropic hormone secretion syndrome is difficult. Initial failure to identify a tumor is common. Pulmonary carcinoid or occult source of ectopic adrenocorticotropic hormone secretion syndrome is usually the cause. In occult cases of ectopic adrenocorticotropic hormone in which the tumor cannot be localized, serial follow-up with serial computed tomography, magnetic resonance imaging, or scintigraphy is recommended for several years until the tumor can be localized and treated.