Computed Tomography Group Research Articles

Negative effects of iodine-based contrast agent on renal function in patients with moderate reduced renal function hospitalized for COVID-19

BackgroundKidney disease and renal failure are associated with hospital deaths in patients with COVID − 19. We aimed to test if contrast enhancement affects short-term renal function in hospitalized COVID − 19 patients.MethodsPlasma creatinine (P-creatinine) was measured on the day of computed tomography (CT) and 24 h, 48 h, and 4–10 days after CT. Contrast-enhanced (n = 142) and unenhanced (n = 24) groups were subdivided, based on estimated glomerular filtration rates (eGFR), > 60 and ≤ 60 ml/min/1.73 m2. Contrast-induced acute renal failure (CI-AKI) was defined as ≥27 μmol/L increase or a > 50% rise in P-creatinine from CT or initiation of renal replacement therapy during follow-up. Patients with renal replacement therapy were studied separately. We evaluated factors associated with a > 50% rise in P-creatinine at 48 h and at 4–10 days after contrast-enhanced CT.ResultsMedian P-creatinine at 24–48 h and days 4–10 post-CT in patients with eGFR> 60 and eGFR≥30–60 in contrast-enhanced and unenhanced groups did not differ from basal values. CI-AKI was observed at 48 h and at 4–10 days post contrast administration in 24 and 36% (n = 5/14) of patients with eGFR≥30–60. Corresponding figures in the eGFR> 60 contrast-enhanced CT group were 5 and 5% respectively, (p < 0.037 and p < 0.001, Pearson χ2 test). In the former group, four of the five patients died within 30 days. Odds ratio analysis showed that an eGFR≥30–60 and 30-day mortality were associated with CK-AKI both at 48 h and 4–10 days after contrast-enhanced CT.ConclusionPatients with COVID − 19 and eGFR≥30–60 had a high frequency of CK-AKI at 48 h and at 4–10 days after contrast administration, which was associated with increased 30-day mortality. For patients with eGFR≥30–60, we recommend strict indications are practiced for contrast-enhanced CT. Contrast-enhanced CT had a modest effect in patients with eGFR> 60.

Diagnostic value of peroral cholangioscopy in addition to computed tomography for indeterminate biliary strictures.

Peroral cholangioscopy (POCS) has been used to overcome the difficulty in diagnosing indeterminate biliary stricture or tumor spread. However, the value of adding POCS to computed tomography (CT) remains unclear. Our aim was to evaluate the diagnostic value of adding POCS to CT for indeterminate biliary stricture and tumor spread by interpretation of images focusing on the high diagnostic accuracy of visual findings in POCS. We retrospectively identified 52 patients with biliary stricture who underwent endoscopic retrograde cholangiography (ERC) at our institution between January 2013 and December 2018. Two teams, each composed of an expert endoscopist and surgeon, performed the interpretation independently, referring to the CT findings of the radiologist. The CT + ERC + POCS images (POCS group) were evaluated 4weeks after the evaluation of CT + ERC images (CT group). A 5-point scale (1: definitely benign to 5: definitely malignant) was used to determine the confident diagnosis rate, which was defined as an evaluation value of 1 or 5. Tumor spread was also evaluated. In the evaluation of 45 malignant diagnoses, the score was significantly closer to 5 in the POCS group than in the CT group in both teams (P < 0.001). The confident diagnosis rate was significantly higher for the POCS group (92% and 73%) than for the CT group (25% and 12%) in teams 1 and 2, respectively (P < 0.001). We found no significant difference in diagnostic accuracy for tumor spread between the groups. Visual POCS findings confirmed the diagnosis of biliary strictures. POCS was useful in cases of indefinite diagnosis of biliary strictures by CT.

CT-Based 3D Reconstruction of Lower Limb Versus X-Ray-Based 3D Reconstruction: A Comparative Analysis and Application for a Safe and Cost-Effective Modality in TKA.

Patient Specific Instrumentation (PSI) with 3D bone models have been used to improve the outcomes of Total Knee Arthroplasty (TKA). The PSI, however, needs a CT (Computed tomography)/MRI scan to reproduce a bone-based model. However, CT is not a routine imaging method in the TKA and has challenges such as high radiation exposure and increased investigation cost. Any technology or software which could accurately recreate 3D bone models using X-ray would be a cheaper and safer tool. This study is based on one such technology (XrayTo3D®) using X-ray to 3D as an alternative to other image-based 3D bone models and PSI available in the market. This study compares the accuracy of XrayTo3D® versus a Conventional CT to 3D, in the reconstruction of lower limb bones (femur and tibia). In an analysis of 45 lower limbs, 11 anatomical parameters were measured [Medial Proximal Tibial Angle-MPTA, Tibial(T)-torsion, T-slope, T-length, Mechanical Lateral Distal Femoral Angle (mLDFA), F-version, F-length, Distal femoral Medio lateral width (F-ML), Distal Femoral Antero Posterior (F-AP), Proximal Tibia Antero Posterior (T-AP), Proximal Tibia Medio Lateral (T-ML) based on landmarks selected by three orthopaedic surgeons(numbers of the authors superscript), on two groups of 3D models, one reconstructed using XrayTo3D® and the other using CT. Mean and standard-deviation values were measured for all the parameters in both the groups. Statistical association between both the groups was measured by Pearson's correlation coefficient. Two-sided t tests of the mean values were calculated to compare the two measurement methods. The interobserver reproducibility within each group was measured by the intraclass correlation coefficient (ICC). Point-to-surface (P2S) error, in the distal femur and proximal tibia regions of the models reconstructed using XrayTo3D®, were also measured. For all the 11 parameters, no statistically significant difference was found between the 2 groups (p > 0.05). Pearson's correlation coefficients for all the parameters were not significant. The interobserver reproducibility was ranging from 0.90 to 1.00 and 0.90 to 1.00 for the XrayTo3D® and CT groups, respectively. The mean P2S distance was 1.0mm in distal femur and 1.1mm in proximal tibia which was within the acceptable limits. The reconstruction accuracy of the XrayTo3D® is an accurate, safe and cost effective as compared to a CT-based method.

Low-Rank Matrix Denoising Algorithm-Based Magnetic Resonance Imaging Combined with Computed Tomography Images in the Diagnosis of Cerebral Aneurysm

This study was to analyze the diagnostic effects of computed tomography (CT) and magnetic resonance imaging (MRI) in patients with cerebrovascular diseases (CVDs) based on low-rank matrix denoising (LRMD) algorithm. The LRMD algorithm was adopted for MRI diagnosis and CT diagnosis for comparative analysis. 129 CVD patients were selected as the research objects, 43 cases were diagnosed by CT, 43 cases were diagnosed by MRI under LRMD, and the other 43 cases were diagnosed by CT + MRI. The results showed that the diagnostic compliance rates (DCRs) of CT group in the cerebral hemorrhage (CH), cerebral infarction (CI), and cerebral aneurysm (CA) were 95.1%, 94.7%, and 70%, respectively, while those in the MRI group were 99.01%, 97.71%, and 100%, respectively. Thus, it was obtained that MRI diagnosis was much better than CT diagnosis, and CT + MRI showed the best diagnosis efficacy, showing statistical differences ( P &lt; 0.05 ). The accuracy, sensitivity, and specificity of MRI diagnosis under the LRMD algorithm were 96.28%, 88.76%, and 90.62%, respectively, which were superior to those of CT diagnosis (92.71%, 84.94%, and 80.71%, respectively). The diagnosis cost per case (DC/C) (799.73 ± 100.02 yuan) and the total diagnosis cost (TDC) (58,521.67 ± 301.62 yuan) in the MRI group were higher than those in the CT group (601.42 ± 83.61 yuan and 39,819.2 ± 198.72, respectively) ( P &lt; 0.05 ). In conclusion, CT + MRI under the LRMD algorithm showed good potential in diagnosis of CVD; MRI based on the LRMD algorithm showed a higher positive rate in the diagnosis of CA and was better than CT diagnosis, and CT + MRI showed the best diagnosis effect and could improve the clinical diagnosis rate.

The accuracy of clinical 3D printing in reconstructive surgery: literature review and in vivo validation study.

A growing number of studies demonstrate the benefits of 3D printing in improving surgical efficiency and subsequently clinical outcomes. However, the number of studies evaluating the accuracy of 3D printing techniques remains scarce. All publications appraising the accuracy of 3D printing between 1950 and 2018 were reviewed using well-established databases, including PubMed, Medline, Web of Science and Embase. An in vivo validation study of our 3D printing technique was undertaken using unprocessed chicken radius bones (Gallus gallus domesticus). Calculating its maximum length, we compared the measurements from computed tomography (CT) scans (CT group), image segmentation (SEG group) and 3D-printed (3DP) models (3DP group). Twenty-eight comparison studies in 19 papers have been identified. Published mean error of CT-based 3D printing techniques were 0.46 mm (1.06%) in stereolithography, 1.05 mm (1.78%) in binder jet technology, 0.72 mm (0.82%) in PolyJet technique, 0.20 mm (0.95%) in fused filament fabrication (FFF) and 0.72 mm (1.25%) in selective laser sintering (SLS). In the current in vivo validation study, mean errors were 0.34 mm (0.86%) in CT group, 1.02 mm (2.51%) in SEG group and 1.16 mm (2.84%) in 3DP group. Our Peninsula 3D printing technique using a FFF 3D printer thus produced accuracy similar to the published studies (1.16 mm, 2.84%). There was a statistically significant difference (P<10-4) between the CT group and the latter SEG and 3DP groups indicating that most of the error is introduced during image segmentation stage.

Effect of Intraoperative Computed Tomography on Ventriculoperitoneal Shunt Survival

In patients with hydrocephalus who undergo ventriculoperitoneal shunt placement, the ventricular catheter tip position is one of the most important prognostic factors influencing shunt survival. The aim of this study was to present our findings of ventriculoperitoneal shunt placement performed with intraoperative computed tomography (CT) and to evaluate the effect of intraoperative CT-based image guidance on optimal catheter positioning and overall shunt survival. Of the study enrolled 345 patients with hydrocephalus who underwent ventriculoperitoneal shunt placement for the first time between 2008 and 2018. Ventricular catheters were inserted freehand via the Kocher point into the lateral ventricle in all patients. In 163 patients, intraoperative CT was performed to confirm the tip position. In this group of patients, if the tip position was nonoptimal, the catheter was ejected and reinserted during the surgery. In the remaining 182 patients, the tip position was assessed with routine postoperative CT. The effect of performing intraoperative CT on catheter tip positioning and shunt failure was investigated. Nonoptimal tip position was significantly correlated with shunt dysfunction even when excluding nonobstructive causes (P < 0.001). In the intraoperative CT group, 11 ventricular catheters (6.7%) were intraoperatively repositioned. The repositioning significantly improved the optimal tip position rate from 54% to 58.3% (P= 0.007). Intraoperative CT usage also showed direct correlation with shunt survival (P= 0.006). Intraoperative CT is an effective tool for increasing the rate of optimal tip positioning and thereby overall shunt survival.

Three-Dimensional Reconstruction Algorithm of Computed Tomography Imaging for Surgical Treatment and Rapid Rehabilitation Nursing of Renal Cell Carcinoma

This study was carried out to explore the promotion role of computed tomography (CT) imaging three-dimensional (3D) reconstruction technology and rapid rehabilitation nursing intervention (RRNI) in the treatment of patients with renal cell cancer (RCC) laparoscopic radical nephrectomy (LRN) in view of the patient’s condition. 98 RCC patients who were admitted to the hospital from July 2019 to July 2020 were selected as the research subjects, and all patients underwent the LRN and the RRIN. Of which, 46 RCC patients were scanned with CT images (regarded as the CT group), and 46 RCC patients were scanned with CT images based on 3D reconstruction algorithms (regarded as the 3D CT group). The clinical efficacy and the life quality, pain degree, and adverse mood changes before and after the RRN were analyzed and compared. The results showed that the surgery time in the 3D CT group and the CT group was 130.2 ± 42.8 minutes and 162.4 ± 38.5 minutes, respectively ( P &lt; 0.05 ). The recurrence rate of RCC in both groups was 0%. The estimated blood loss in the 3D CT group and the CT group was 93.6 ± 35.5 mL and 90.3 ± 40.2 mL, respectively; the complication rate in the 3D CT and CT group was 5% and 12%, respectively; the hospital stay in the 3D CT and CT group was 12.5 ± 4.7 days and 12.1 ± 3.2 days, respectively, which had no statistical significance ( P &gt; 0.05 ). The scores of visual analogue scale (VAS), 36-Item Short-Form Health Survey (SF-36), self-rating depression scale (SDS), and self-rating anxiety scale (SAS) of patients in the two groups were statistically significant ( P &lt; 0.05 ). It indicated that CT images based on the 3D reconstruction algorithm could be applied in LRN of RCC patients to shorten the surgery time and improve the surgical effect, and implementation of the RRN could relieve the adverse mood of RCC patients and effectively improve their life quality.

Does use of pre-operative low-dose CT-scan in adolescent idiopathic scoliosis improve accuracy in screw placement? Results of a retrospective study.

To evaluate the efficacy of pre-operative low-dose radiation computed tomography (CT) in optimizing screw placement in patients with adolescent idiopathic scoliosis (AIS). 49 patients with AIS who required correction and posterior fusion between January 2018 and December 2019 were included in this retrospective study. All patients underwent surgery performed by the same team of experienced surgeons. Patients were divided in two groups. The study group received a pre-operative low-dose CT scan (CT group, n = 25), differently from the control group (CG, n = 24). Patients of both groups received a post-operative low-dose CT scan. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale (grades A and B were considered acceptable). Secondary outcome measures included a comparison of perioperative complications. A total of 1045 screws were placed. In CT group (n = 25, screws = 528) and CG (n = 24, screws = 517), trajectories were grade A or B in 94.5% and 93.6% of screws, respectively. Two screws (one for each group) were removed because of intra-operative-evoked potentials alteration and one screw required revision after post-operative imaging. No correlation was found between the malpositioning rate and the proximity to the apex of the curve, conversely a significative peak of misplacements was observed at T3 (p < 0.01). No neurological and vascular complications related to screw placement were recorded. There was not intergroup difference neither in screw accuracy (Chi-Square, 2-tailed Fisher's exact, p = 0.63), nor in complications rate. Pre-operative low-dose CT scan as surgical plan does not contribute in reducing pedicle screw misplacement rate. Retrospective comparative cohort study. III.

Mind the Gap: Alveolar Bone Graft Revision in the Era of Computed Tomography.

To determine the rate of revision alveolar bone grafting (ABG) in patients with cleft lip and palate (CLP) before and after the introduction of postoperative computed tomography (CT). Retrospective case-control study analyzing the incidence of revision ABG in patients with and without postoperative CT scans for graft success evaluation. Academic tertiary care pediatric hospital. Eighty-seven patients with CLP or cleft lip and alveolus treated with autologous iliac crest bone grafting for alveolar clefts over a 10-year period (January 2009 to March 2019) with minimum 6-month follow-up. Fifty patients had postoperative CT evaluation; 37 did not. Postoperative CT to determine ABG success, versus standard clinical examination and 2-dimensional radiographs. Requirement for revision ABG, defined as failure of the original graft by clinical or radiographic examination. Fifty-eight percent of patients underwent a postoperative CT scan at median interval of 10 months after surgery. Patients with postoperative CT evaluation had a 44% rate of revision ABG (22/50) for inadequate graft take, compared to 5% (2/37) in patients without postoperative CT (P < .001; 95% CT, 31%-58% in the CT group, 1%-16% in the non-CT group). Computed tomography evaluation after ABG is associated with a significantly increased revision rate for inadequate graft take. The presence of a secondary palatal fistula at the time of original ABG is not associated with revision requirement. Lack of standardized dental and orthodontic records complicates the study of ABG outcomes and presents an area for systems-based improvement.

Comparison of the CBCT, CT, 3D Printing, and CAD-CAM Milling Options for the Most Accurate Root Form Duplication Required for the Root Analogue Implant (RAI) Protocol

Background: A computerized tomography (CT) scan or a cone beam computerized tomography (CBCT) imaging techniques can be used for tooth segmentation and acquisition of a three-dimensional (3D) reconstruction using CADCAM milling and 3D printing methods. Aim: This experimental study was done to assess the accuracy of CBCT, CT, CAD-CAM milling, and 3D printing for acquiring the most accurate duplication for root analog implant (RAI). Materials and Methods: The study was an ex-vivo feasibility study comparing CBCT, CT, CAD-CAM milling, and 3D printing methods for acquiring the most accurate duplication for root analog implant (RAI). Informed consent was obtained from patients for the study purpose for recording CT and CBCT scans and to utilize the extracted teeth for research purpose. The teeth were segmented from the DICOM files of CBCT and CT scans of the patients and Standard Tessellation Language files (STL) were obtained for individual teeth. The STL files of the individual teeth obtained were printed and milled in polymethylmethacrylate material (PMMA). The study thus consisted of 5 groups—Natural teeth as control, CBCT milled group, CT milled group, CBCT printed group and CT printed group of 16 samples each. Morphological differences in the three dimensions namely apico-coronal, bucco-lingual, and mesio-distal between the natural tooth and the 3D replicas were assessed using the one-way ANOVA test using the statistical software. Results: There was no statistically significant difference among the dimensions between the CBCT, CT, CAD-CAM milling, and 3D printing groups with respect to the most accurate duplication for root analog implant (p &gt; 0.05). Conclusion: Within the limitations of this study, the CBCT segmentation and the Milling technique produce the least distortion for fabricating the root analog implant.

3D CT airway evaluation-guided intraluminal placement of endobronchial blocker in pediatric patients: a randomized controlled study.

BackgroundThe aim of the present study was to propose a new approach for 3D computed tomography (CT) airway evaluation-guided endobronchial blocker placement in pediatric patients, and to determine its efficiency in clinical application.MethodsA total of 127 pediatric patients aged 0.5–3 years who were scheduled for elective thoracic surgery using one-lung ventilation (OLV) were randomized into the bronchoscopy (BRO) group and the CT group. The degree of lung collapse, postoperative airway mucosal injury, pulmonary infection within 72 h after surgery, and hoarseness after tracheal extubation; duration of postoperative mechanical ventilation, intensive care unit (ICU) stay and hospitalization; success rate of first blocker positioning; and required time and repositioning for successful blocker placement were compared between the 2 groups.ResultsThe degree of lung collapse, postoperative airway mucosal injury, pulmonary infection within 72 h after surgery, and hoarseness after tracheal extubation; duration of postoperative mechanical ventilation, ICU stay and hospitalization; success rate of first blocker positioning; and required time and repositioning for successful blocker placement were similar between the 2 groups (all P>0.05).ConclusionsFor pediatric patients undergoing surgery with OLV, preoperative 3D CT airway evaluation could be used to guide endobronchial blocker placement, with a blocking efficiency similar to that of BRO-guided blocker placement.

Contrast-enhanced computed tomography prior to percutaneous transthoracic needle biopsy reduces the incidence of hemorrhage

BackgroundHemorrhage is the second most common complication of percutaneous transthoracic needle biopsy (PTNB), and at present, there is no effective prevention strategy. Contrast-enhanced computed tomography (CECT) has the advantage of clearly visualizing blood supply within the lesion and aiding in the imaging of blood vessels, which can reduce hemorrhage complicating PTNB. As no large-sample studies were evaluating whether CECT could reduce hemorrhage, we conducted the present retrospective study.MethodsFrom November 2011 to February 2016, 1,282 biopsies at Jinling Hospital were retrospectively reviewed; 555 underwent CECT, and 727 underwent non-contrast computed tomography (CT). Factors associated with hemorrhage were defined, and hemorrhage rates were compared between the 2 groups.ResultsWe found that pre-biopsy CECT was associated with a reduced incidence of biopsy-related hemorrhage compared to non-contrast CT (16.4% vs. 23.1%, P=0.003). Propensity score matching (PSM) analysis also showed that the incidence of hemorrhage in the CECT group was lower than that of the non-contrast CT group at a ratio of 1:1 (P=0.039), 1:2 (P=0.028), or 1:3 (P=0.013). In the multivariate analysis, CECT before PTNB was found to be significantly associated with a reduced risk of hemorrhage [odds ratio (OR): 0.671, 95% confidence interval (CI): 0.499–0.902, P=0.008]. Puncture position, lesion size, depth of needle tract, and the number of punctures were also found to be associated with hemorrhage (all P<0.05).ConclusionsCompared with non-contrast CT, CECT significantly reduced the risk of post-biopsy pulmonary hemorrhage, which suggests that CECT should be performed before PTNB.

Validation of 3D fluoroscopy for image-guidance registration in depth electrode implantation for medically refractory epilepsy.

Frame registration is a critical step to ensure accurate electrode placement in stereotactic procedures such as stereoelectroencephalography (SEEG) and is routinely done by merging a computed tomography (CT) scan with the preoperative magnetic resonance (MR) examination. Three-dimensional fluoroscopy (XT) has emerged as a method for intraoperative electrode verification following electrode implantation and more recently has been proposed as a registration method with several advantages. We compared the accuracy of SEEG electrode placement by frame registration with CT and XT imaging by analyzing the Euclidean distance between planned and post-implantation trajectories of the SEEG electrodes to calculate the error in both the entry (EP) and target (TP) points. Other variables included radiation dose, efficiency, and complications. Twenty-seven patients (13 CT and 14 XT) underwent placement of SEEG electrodes (319 in total). The mean EP and TP errors for the CT group were 2.3 mm and 3.3 mm, respectively, and 1.9 mm and 2.9 mm for the XT group, with no statistical difference (p = 0.75 and p = 0.246). The time to first electrode placement was similar (XT, 82 ± 10 min; CT, 84 ± 22 min; p = 0.858) and the average radiation exposure with XT (234 ± 55 mGy*cm) was significantly lower than CT (1245 ± 123 mGy*cm) (p < 0.0001). Four complications were documented with equal incidence in both groups. The use of XT as a method for registration resulted in similar implantation accuracy compared with CT. Advantages of XT are the substantial reduction in radiation dose and the elimination of the need to transfer the patient out of the room which may have an impact on patient safety and OR efficiency.

Trueness and Precision of Three Different Scanners for Digitizing a Completely Edentulous Gypsum Model

Purpose: The aim of this in vitro study was to evaluate the precision and trueness of three different scanners to scan a maxillary edentulous model using three-dimensional evaluation software. Materials and Methods: A coordinate measuring machine was used as the reference scanner. Cone beam computed tomography, computed tomography (CT), and an intraoral scanner were used to digitize an edentulous gypsum model. Data were collected and loaded into three-dimensional evaluation software. The scan outputs were superimposed, and the accuracy (trueness and precision) of the scanners were compared. One-way ANOVA was used to compare the accuracy values among all groups (trueness) and to determine differences within groups (precision). Statistical significance was assessed with an independent sample t-test (= 0.05) for each group. Results: The mean precision values ranged from 3.5 to –0.2 m. Analysis of the superimposed scans onto the reference scan for each group revealed no significant differences in trueness and precision (p &gt; 0.05) among all groups. Further, binary comparisons of the datasets of each group revealed no significant differences (p &gt; 0.05) in terms of precision values, except in the CT group wherein significant differences (p ≤ 0.05) were observed for most models. Conclusions: No significant differences were observed in terms of accuracy (precision and trueness) among the three scanners. All scanners were effective in scanning the edentulous gypsum model.

Navigation and non-navigation CT scan of the sinuses: comparison of the effective doses of radiation in children and adults

BackgroundThe advent of 3D navigation imaging has opened new borders to the endoscopic surgical approaches of naso-sinusal inflammatory and neoplastic disease. This technology has gained in popularity among otolaryngologists for endoscopic sinus and skull base surgeries in both adults and children. However, the increased tissue radiation required for data acquisition associated with 3D navigation protocols CT scans is a source of concern because of its potential health hazards. We aimed to compare the effective doses of radiation between 3D navigation protocols and standard protocols for sinus computed tomography (CT) scans for both the adult and pediatric population.MethodsWe performed a retrospective cohort study through electronic chart review of patients undergoing sinus CT scans (standard and 3D navigation protocols) from May 2019 to December 2019 using a Siemens Drive (VA62A) CT scanner. The effective dose of radiation was calculated in mSv for all exams. Average irradiation doses were compared using a Student’s T-Test or a Kruskall–Wallis test when appropriate.ResultsA total of 115 CT scans were selected for analysis, of which 47 were standard protocols and 68 were 3D navigation protocols CT scans. Among these, 31 exams were performed on children and 84 exams on adults. For the total population, mean effective dose in the non-navigation CT scans was 0.37 mSv (SD: 0.16, N = 47) and mean effective dose in the 3D navigation sinus CT group was 2.33 mSv (SD: 0.45, N = 68). The mean difference between the two groups was statistically significant 1.97 mSv (CI 95% − 2.1 to − 1.83; P < 0.0001). There was a sixfold increase in radiation with utilization of 3D navigation protocols. The ratio was identical when the pediatric as well as the adult subset of patients were analyzed.ConclusionIn our center, utilization of 3D navigation sinus CT protocols significantly increases radiation exposure. Otolaryngologists should be aware of this significant increase and should attempt to decrease the radiation exposure of their patients by limiting unnecessary scan orders and by evaluating 3D acquisition protocols locally with radiation physicists.Level of evidence: Level IV.Graphical

The Predictive Value of Initial CT Scan in Patients with COVID-19

Background: As the pandemic of coronavirus disease 2019 (COVID-19) in Wuhan raised public health concerns, many studies were conducted to reveal the risk factors of the disease and predictive prognostic indicators to plan the treatment strategies and commence therapies earlier. Although specific parameters, including age, gender, chronic diseases, D-dimer, and neutrophil-lymphocyte-ratio play a curial role in COVID-19, the association between mortality and the extent of lung involvement in the initial computerized tomography (CT) scan of patients diagnosed with COVID-19 has not been well documented in the literature. Objectives: We compared two groups (CT-1 and CT-2) in terms of lung involvement in the initial CT of patients admitted to the emergency unit and then hospitallzed with COVID-19. Methods: Using the digital data system of İzmir Bozyaka Training and Research Hospital, Turkey, subjects diagnosed with COVID-19 in April 2020 were retrospectively screened. For each of the 90 patients, the initial CT scans on admission were evaluated for the extent of lung involvement and classified as CT-1 (≤ 5% of lung involvement, n: 45) and CT-2 (&gt; 5% of lung involvement, n: 45). Results: There was not any statistical significance between two different CT groups regarding mortality and length of stay of patients in hospital with COVID-19 (P = 0.72 and P = 0.51, respectively). Neutrophil counts were found to be statistically significant and higher in CT-2 group than the CT-1 (P = 0.02) group. The length of stay in hospital was correlated with age, neutrophil-lymphocyte ratio (NLR), neutrophils, lymphocyte, and only the correlation between length of stay in hospital and age was significant (P = 0.01). Conclusions: The size of involvement is not a predictive indicator for mortality and length of stay in hospital in patients with COVID-19.

Assessing the Clinical Value of Performing CT Scan before Rhinoplasty Surgery.

Introduction The endonasal mucosal or anatomic pathologies could lead to poor functional results and dissatisfaction after rhinoplasty. Although computed tomography (CT) scan has become an integral part of the diagnostic paradigm for patients with pathologies of the paranasal sinuses, the use of CT scan for preoperative evaluation of patients seeking rhinoplasty is up for debate. Our aim in this study was to compare the efficacy of CT scan in diagnosing nasal pathologies with other evaluating tools in patients undergoing rhinoplasty. Design In this randomized controlled trial study, 74 consecutive patients seeking cosmetic rhinoplasty referred to otorhinolaryngology clinic were randomly assigned into three groups based on the perioperative evaluation method: the CT group, the nasal endoscopy group, and the control group (anterior rhinoscopy only). Surgical planning was made according to perioperative findings, and the identified endonasal pathologies were corrected during the surgery. The functional and aesthetic outcomes of the rhinoplasty were assessed by Nasal Obstruction Symptom Evaluation (NOSE), Rhinoplasty Outcome Evaluation (ROE), and the Visual Analogue Scale (VAS) tools before surgery and at 12-month follow-up. Results All outcome measures improved significantly in either group toward one year after rhinoplasty (all with p value <0.05). Subjects in the CT group demonstrated greater improvement in the NOSE, VAS, and ROE compared to other two groups (NOSE: p value = 0.17; VAS: p value = 0.024; ROE: p value = 0.042). Conclusions According to our study, perioperative CT is associated with greater patients' satisfaction and quality of life after rhinoplasty compared to either nasal endoscopy or anterior rhinoscopy. A preoperative CT scan may improve the outcomes of rhinoplasty.

Assessment of the Clinical Usefulness of Preoperative Computed Tomography in Colorectal Cancer Patients Who Received Unplanned Reoperation.

Background In the unplanned reoperation of colorectal cancer patients, computed tomography (CT) is increasingly utilized to locate postoperative complications and previously unlocalized lesions. The purpose of this study is to explore the application of CT in the mortality and complications of the reoperation of colorectal cancer. Patients and Methods. We performed a retrospective review of collected data from the colorectal surgeries of 90 identified colorectal cancer patients who received an unplanned reoperation from 2010 to 2018. Patients were stratified according to those with preoperative CT imaging (CT group, n = 36) and those without preoperative CT imaging (NCT group, n = 54). Twenty-four statistical indicators of each patient were studied, including their preoperative risk, surgical characteristics, and postoperative outcomes, and satisfaction was evaluated. All data were statistically analysed for predicting postoperative complications by univariate and multivariate logistic regression analyses. Results Ninety patients received an unplanned reoperation in the study, and 40% (36/90) of these patients underwent preoperative CT examination. Patients' risk factors were similar between CT and NCT groups. Preoperative imaging was more commonly performed for reoperative new anastomosis + ileostomy but less common for reoperative Dixon's procedure. The operative duration of the NCT group was longer (139 vs. 104 min, respectively, P = 0.01). Preoperative NCT examination (OR 1.24; 95% CI = 1.09‐1.42; P = 0.01) was an independent predictor of postoperative complications. Importantly, three patients died after an unplanned reoperation for colorectal cancer, which occurred only in the NCT group (5.6% vs. 0.0%, P = 0.01). Conclusion The use of conventional preoperative CT optimizes the choice of the surgical site and the strategy of laparotomy, so as to reduce the length of operation. Preoperative imaging evaluation should be performed for patients undergoing repeat abdominal surgery.

Comparison on radiation effective dose and image quality of right coronary artery on prospective ECG-gated method between 320 row CT and 2nd generation (128-slice) dual source CT.

This retrospective study was to compare the image quality of right coronary artery (RCA) and effective radiation dose on prospective ECG‐gated method between 320 row computed tomography (CT) and 2nd generation (128‐slice) dual source CT. A total of 215 candidates underwent CT coronary angiography using prospective ECG‐gated method, 120 patients enrolled in 320 row CT group, and 95 patients in dual source CT group. We divided RCA image quality scores as 1/2/3/4, which means excellent/good/adequate/not assessable and heart rates were considered, as well as the radiation dose. There is no statistically significant difference of RCA image quality of Score 1/2 between 320 row CT and 2nd generation dual source CT, but lower heart rate (<70/min) improved RCA image quality. Meanwhile, the 2nd generation dual source CT scan have significant lower radiation dose. For patients with high level heart rate variation, both prospective ECG‐gated method of 320 row CT scan (Toshiba) and 2nd generation dual source CT scan (Siemens) basically provided good image quality on RCA. There is an advantage of effective radiation dose reduction in prospective ECG‐gated method using the 2nd generation dual source CT scan. After the iodine contrast agent was injected into elbow vein, the threshold triggering method was used to carry out prospective gated scanning, and the acquired fault image was reconstructed by the standard post‐processing software of each manufacturer. The radiation dose value is obtained through the dose report automatically generated after each scan.

Ultra-low-dose CT-guided lung biopsy in clinic: radiation dose, accuracy, image quality, and complication rate.

Computed tomography (CT)-guided percutaneous lung biopsy is usually performed by helical scanning. However, there are no studies on radiation dose, diagnostic accuracy, image quality, and complications based on axial scan mode. To determine radiation dose, accuracy, image quality, and complication rate following an ultra-low-dose (ULD) protocol for CT-guided lung biopsy in clinic. A total of 105 patients were enrolled to receive CT-guided lung biopsy. The use of an ULD protocol (axial scan) for CT-guided biopsy was initiated. Patients were randomly assigned to axial mode (Group A) and conventional helical mode (Group B) CT groups. 64-slice CT was performed for CT-guided pulmonary biopsy with an 18-G coaxial cutting biopsy needle. The radiation dose, accuracy, image quality, and complication rate were measured. Ninety-seven patients were selected for the final phase of the study. There was no significant difference between the two groups for pulmonary nodule characteristics (P > 0.05). The mean effective dose in group A (0.077 ± 0.010 mSv) was significantly reduced relative to group B (0.653 ± 0.177 mSv, P < 0.001). There was no significant difference in accuracy, image quality, and complication rate (P > 0.050) between the two modes. An ULD protocol for CT-guided lung nodule biopsy yields a reduction in the radiation dose without significant change in the accuracy, image quality, and complication rate relative to the conventional helical mode scan.