Computed Tomography Software Research Articles

Abstract 4128606: Detailed Measurements of Surgical Mitral Valves: Implications for Transcatheter Mitral Valve-in-Valve Interventions

Background: With the increasing prevalence of transcatheter mitral valve-in-valve interventions (V-in-V), a detailed understanding of the surgical valves (SV) is of paramount importance. Left ventricular outflow tract obstruction (LVOTO) is a feared complication and is typically caused by the anterior displacement of the LVOT-facing surgical leaflet, which, along with the surgical post at that level, forms a fixed obstruction. Traditionally, the risk is estimated using computed tomography software by simulating a valve that extends to the surgical post height of the implanted SV. However, this does not account for the actual leaflet length and post width at the level of the leaflet tip, which could differ significantly from the surgical post height but accurately estimate LVOTO risk. Methods: We conducted detailed measurements of three different sizes of two commonly used surgical mitral valves: the Biocor EPIC ( Abbott ) in sizes 27 mm, 31 mm, and 33 mm, and the Mosaic ( Medtronic ) in sizes 25 mm, 31 mm, and 33 mm. Using a digital caliper and height gauge, we measured several key parameters for each valve, including leaflet height, post height, leaflet width, post width at the level of the leaflet tip, maximal post width, and valve inner diameter. Results: The results, presented in Table 1, show significant differences in leaflet height and post widths across manufacturers and sizes. Leaflet height was consistently shorter than post height in both Abbott and Medtronic valves, with this discrepancy more pronounced in larger valves and Medtronic valves. The post width at the leaflet tip also varied considerably. Conclusions: Given the substantial differences between leaflet and post heights—with the leaflet typically much shorter—an accurate assessment of LVOTO risk should account for both the leaflet height and the width of the post at that level to avoid overestimating the risk of LVOTO.

Spatial and angular alterations in the dental arch after premature loss of primary molars: Immediate and 9-month computed tomography evaluation.

Contemporary imaging methods and quickly advancing technologies have increased the number of diagnostic tools available in medicine and orthodontics. The current study aimed to determine three-dimensional (3D) space changes that occurred after the extraction of either the maxillary or mandibular primary molars during the mixed dentition period. The present study was a longitudinal split-mouth study with a study group and a control group. The sample consisted of 20 children aged between 6 and 9 years. Clinical examination, radiological analysis, and 3D digital images of the plaster casts were used sequentially to gather all the data. The dental cast measurements recorded were arch width, arch length, hemi-perimeter, dental space at the extraction site, and angulation of the first permanent molar. The children were recalled for follow-up after 9 months, and all dental cast measurements were repeated using nondestructive 3D computed tomography software. For repeated measurements, the test applied was a paired t-test, and for independent samples, the test was a Student's t-test. A significant decrease in arch width (P = 0.001), arch length (P < 0.001), hemi-perimeter (P < 0.001), D-space (P < 0.001), and E-space (P = 0.001) was observed following extraction. A significant increase in angulation measurements was observed (P = 0.001). The study revealed a comparative reduction in mandibular arch width, a reduction in arch length in both the maxilla and the mandible, a reduced hemi-perimeter of dental arches, loss of dental extraction space, and a change in angulation of the erupted first permanent molars following premature loss of the primary molar.

TREATMENT OF YATROGENIC POST-TRAUMATIC NEUROPATHY ASSOCIATED WITH ENDODONTIC THERAPY USING 3D TECHNOLOGIES

Post-traumatic neuropathy is one of the complications of endodontic treatment, represents a serious problem, manifested by sensory disturbances and has a significant negative impact on the quality of life of patients. Mechanical pressure on the filler causes swelling and hematoma and, due to the chemical action of the substance, neurotoxicity. The decision to treat a patient with trigeminal neuropathy requires complex treatment. Early surgical removal of excess endodontic material resulting from endodontic treatment provides the best prognosis for recovery. With the development of modern digital technologies, advances have been made in the endodontic treatment process. The presented clinical case describes original method for the treatment of endodontic inferior alveolar nerve injuries associated with endodontic therapy using surgical template obtained by three-dimensional software modeling. Using computed tomography software, a template was developed for drilling the bone in the projection of the localization of the material. The surgical template is printed with a 3D printer, after installation in the oral cavity, osteotomies are made under X-ray and excess material is removed, after which the patient is prescribed complex treatment. Results: After 2 weeks, the patient&amp;#39;s complaints disappeared. Sensory impairments were restored and had a positive impact on the patient’s quality of life. A control X-ray examination revealed regeneration of young bone tissue at the osteotomy site. Conclusion: The introduction of digital planning software and the use of 3D printed surgical guides in endodontic microsurgery have significantly improved treatment planning as well as operative and psychological comfort for patients.

Sublobar resection or lobectomy and postoperative respiratory complications in emphysematous lungs.

Pulmonary resection in patients with severe emphysema may impact postoperative respiratory complications. Low-attenuation areas evaluated using three-dimensional computed tomography to assess emphysematous changes are strongly associated with postoperative respiratory complications. Herein, we investigated the relationship between low-attenuation area, the surgical procedure and resected lung volume, which has not been explored in previous studies. We retrospectively evaluated patients with primary or metastatic lung cancer who underwent surgical resection. The low-attenuation area percentage (low-attenuation area/total lung area × 100) and resected lung volume were calculated using three-dimensional computed tomography software, and the relationship with postoperative respiratory complications was analysed. Postoperative respiratory complications occurred in 66 patients (17%) in the total cohort (n = 383). We set the median value of 1.1% as the cut-off value for low-attenuation area percentage to predict postoperative respiratory complications, which occurred in 24% and 10% of patients with low-attenuation area >1.1% and <1.1%, respectively (P < 0.001). Postoperative respiratory complications occurred in approximately one-third of the patients with low-attenuation area >1.1%, whose resected lung volume was ≥15.8% or ≥5 resected subsegments. Multivariable analysis revealed that sublobar resection was associated with a significantly lower risk of postoperative respiratory complications in patients with low-attenuation area >1.1% (odds ratio 0.4, 95% confidence interval 0.183-0.875). Emphysema is a risk factor for postoperative respiratory complications, and lobectomy is an independent predictive risk factor. Preserving more lung parenchyma may yield better short-term prognoses in patients with emphysematous lungs.

Accuracy of Cone-Beam Computed Tomography Software in Predicting the Size of Impacted Canine: A Preliminary Study.

To compare and analyze the precision, accuracy, and reliability of commonly used cone-beam computed tomography (CBCT) software in predicting the mesiodistal diameter of impacted canines. This study was conducted on 11 patients (six males and five females, mean age: 17.5±5.5 years) with either unilateral or bilateral impacted canines in the maxilla or mandible. DICOM data sets of the patients obtained from CBCT scans were then loaded and visualized with four selected CBCT software to measure the widest mesiodistal diameter of the impacted teeth. Physical measurements using a digital vernier caliper, kept as a control, were also made on the extracted teeth and orthodontically erupted teeth. The collected data underwent statistical analysis, and the statistical significance level was set at p<0.05. The Bland-Altman analysis was performed to quantify the agreement between different software to the digital caliper, showing a narrow difference for all plots. Kruskal-Wallis ANOVA test followed by a post hoc test was performed to determine whether there was any difference in measuring the mesiodistal diameter of the impacted canine among the five methods, and tend no statistically significant difference was found among the five methods. Intraclass correlation (ICC) was performed, and measurements made with all CBCT software yielded an ICC greater than 0.95, indicating high reliability of the selected software. All the evaluated CBCT imaging software exhibited a high degree of reliability, and accuracy in precise measurement of the mesiodistal diameter of an impacted tooth.

CT quantitative analysis of pulmonary changes in rheumatoid arthritis.

To explore the application of quantitative computed tomography (CT) in analyses of lung changes in patients with rheumatoid arthritis (RA). A total of 150 clinically diagnosed RA patients underwent chest CT and 150 matched non-smokers subjects with normal chest CT are enrolled. A CT software is applied to analyze CT obtained from both groups. The quantitative indices of emphysema are expressed as the percentage of lung area with attenuation < -950HU to the total lung volume (LAA-950%), and pulmonary fibrosis was expressed as the percentage of lung area with a attenuation of -200 to -700HU to the total lung volume (LAA-200--700%), quantitative indicators of pulmonary vascular include aortic diameter (AD), pulmonary artery diameter (PAD), the ratio of PAD to AD (PAD/AD ratio), the number of blood vessels (TNV), and the cross area of blood vessels (TAV). The receiver operating characteristic (ROC) curve is used to evaluate the ability of these indexes in identifying the changes in the lung in RA patients. Compared to the control group, the RA group has significantly lower TLV, larger AD, and smaller TNV and TAV (3921±1101 vs. 4490±1046, 33.26±4.20 vs. 32.95±3.76, 13.14±4.93 vs. 17.53±3.34, and 96.89±40.62 vs. 163.32±34.97, respectively, with all p < 0.001). Peripheral vascular indicator TAV has the better ability to identify lung changes in RA patients (area under ROC curve AUC = 0.894) than TNV (AUC = 0.780) or LAA-200&sim-700% (AUC = 0.705). Quantitative CT can detect changes in lung density distribution and peripheral vascular injury in patients with RA and assess the severity.

Accuracy of Blueprint in Predicting Range of Motion One Year After Reverse Total Shoulder Arthroplasty.

/hypothesis: Blueprint 3D CT software has a functionality that predicts impingement-free range of motion with the limits of range of motion determined at which bone and/or prosthetic impingement occurs. To the best of knowledge, there is only one previously published study that assessed the ability for the Blueprint software to predict actual postoperative range of motion after reverse total shoulder arthroplasty. The hypothesis of this study was that 1) mean Blueprint predicted impingement-free range of motion will be statistically similar to the mean actual range of motion one year after reverse total shoulder arthroplasty and 2) there will be a correlation between Blueprint predicted impingement-free range of motion and the actual range of motion one year after reverse total shoulder arthroplasty. A retrospective review of patients that had Blueprint planning prior to undergoing reverse total shoulder arthroplasty from March 2017 through May 2021 was reviewed. At one-year follow-up. flexion, external rotation at the side, abduction, abduction / external rotation, abduction / internal rotation, and internal rotation behind the back were measured. The preoperatively predicted flexion, extension, abduction, external rotation, and internal rotation were recorded from the Blueprint software. Group 1 analysis examined the predicted vs actual range of motion for all 127 patients regardless if intraoperative component modifications were made. Group 2 examined the predicted vs actual range of motion of only the patients that did not have intraoperative changes that would affect the preoperative range of motion prediction (n=97). Group 3 examined the predicted vs actual range of motion of Group 2 combined with the 30 patients that had post-hoc Blueprint planning modifications to account for the changes made intraoperatively (combined sample size = 127). One-hundred-twenty-seven patients of the 141 patients (90%) were available for one year follow-up. When examining the mean of all three groups, the actual range of motion and predicted range of motion was statistically significantly different (p<0.0001) for flexion, external rotation, abduction, abduction/ external rotation, and abduction / internal rotation. In Group 1, a very weak or poor correlation was found between predicted internal rotation and actual abducted/internal rotation (r=0.19; p=0.04). For all other range of motion metrics in Groups 1, 2, and 3, there were no correlations between predicted and actual range of motion (p >.07). In its current state, preoperative Blueprint 3D CT planning software is unable to accurately predict range of motion one year after reverse total shoulder arthroplasty.

Estimation of organ-specific cancer and mortality risks associated with common indication-specific CT examinations of the abdominopelvic region

IntroductionThere is a paucity of large-scale studies reporting organ doses and cancer risks in patients who undergo indication-specific CT examinations. This study estimated organ-specific lifetime attributable risk (LAR) of cancer incidence and mortality among patients who underwent indication-based computed tomography (CT) examinations [(involving abdominopelvic lesion, kidney stones and computed tomography-intravenous urography (CT-IVU)] in about 70% of the functioning CT facilities in Ghana. MethodsWith a total of 1,100 data sets, organ doses were first determined using the National Cancer Institute Dosimetry System for CT (NCICTX) software version 2.1, and LAR values were predicted using the BEIR VII model. ResultsThe estimated radiation-induced colon cancer risks were likely in 39.4-59.8 out of 100,000 patients who underwent CT because of abdominopelvic lesion. The risk was even higher in CT-IVU examinations (53.3-66.4 patients in 100,000 procedures) but was relatively less (16.8-26.3 patients) in kidney stone procedures. Accordingly, the risk of radiation-induced colon mortality was more common in CT-IVU than in kidney stone procedures (22.7-28.2 versus 7.2-12.5 patients in 100,000 procedures). ConclusionThese results call for further optimisation actions for indication-specific CT examinations to appropriately reduce the potential risk levels for patients’ protection and safety.

Estimation of radiation doses and lifetime attributable risk of radiation-induced cancer in the uterus and prostate from abdomen pelvis CT examinations.

Computed tomography (CT) scans are one of the most common radiation imaging modalities, and CT scans are rising steadily worldwide. CT has the potential to enhance radiography practice, but it also has the risk of drastically increasing patient doses. One CT procedure for the abdomen pelvis (AP) area can expose a patient's prostate or uterus to a substantial radiation dose, leading to concerns about radiation-induced cancer. This study aimed to estimate organ doses of the uterus and prostate and evaluate the lifetime attributable risk (LAR) of cancer incidence and mortality resulting from AP CT examinations. This retrospective study included 665 patients, of which 380 (57%) were female, and 285 (43%) were male. Data were collected from the picture archiving and communication system for AP CT procedures and exposure parameter data. Organ doses for the uterus and prostate were calculated using National Cancer Institute CT (NCICT) software. Based on the risk models proposed by the BEIR VII report, the calculated organ doses were used to estimate the LAR of prostate and uterus cancer incidence and mortality due to radiation exposure from AP CT procedures. The mean effective dose resulting from AP CT for females and males was 5.76 ± 3.22 (range: 1.13-12.71 mSv) and 4.37 ± 1.66 mSv (range: 1.36-8.07 mSv), respectively. The mean organ dose to the uterus was 10.86 ± 6.09 mGy (range: 2.13-24.06 mGy). The mean organ dose to the prostate was 7.00 ± 2.66 mGy (range: 2.18-12.94 mGy). The LAR of uterus and prostate cancer incidence was 1.75 ± 1.19 cases and 2.24 ± 1.06 cases per 100,000 persons, respectively. The LAR of cancer mortality rates from uterus and prostate cancers were 0.36 ± 0.22 and 0.48 ± 0.18 cases per 100,000 persons, respectively. The LAR of prostate and uterus cancer occurrence and mortality from radiation doses with AP CT procedures was low but not trivial. Therefore, efforts should be made to lower patient doses while retaining image quality. Although the minimization of the patient's radiation dose must guide clinical practice, the estimated slight increase in risk could aid in easing fears regarding well-justified AP CT procedures.

Comparison of orbital volume measured using computed tomography and fluid displacement: A comparative study using dry skull

Objectives: The purpose of the study was as follows: (1) To compare orbital volume calculated using computed tomography (CT) scans with real-time measurements. (2) To evaluate if the orbital volume of the adjacent orbit can be taken as a tool of comparison for orbital volume correction in orbital fractures. Materials and Methods: A prospective study was conducted on 30 orbital cavities with intact orbital walls. The foramina and fissures were sealed using molding wax. Alginate impressions of the orbital cavity were taken to determine the orbital volume using the Archimedes principle. GE light speed 64 slices CT scanner was used to scan the orbits with 0.8 mm sections. Orbital volume was calculated using the CT software GE ADW 4.5 workstation. Results: The comparison of CT measurement and Archimedes principle measurement shows a mean and standard error of 0.2333 mm and 0.09794, respectively, on the right orbits and a mean and standard error of 0.10011 mm and 0.0981, respectively, on the left orbits. The comparison of the right and left orbits shows a mean and standard error of 0.4067 mm and 0.2771 mm, respectively, using the Archimedes principle and a mean and standard error of 0.3300 mm and 0.2775, respectively, using CT scans. Conclusion: It was found that the difference in orbital volume between CT and real-time measurement is very negligible. The study shows that CT is a reliable tool for the orbital volume measurement and the adjacent orbit can be taken as a comparative tool for the orbital volume corrections.

Prognostic impact of coronary artery calcifications in patients with newly diagnosed prostate cancer

Abstract Background Patients diagnosed with prostate cancer (PCa) are known to be at increased risk of cardiovascular events. Because of the ageing population and better cancer treatment, the number of these patients is increasing. A prostate-specific membrane antigen positron emission tomography (PSMA-PET) is guideline recommended as part of the diagnostic workup. This scan includes a non-ECG-gated computed tomography (CT) of the thorax, allowing assessment of coronary artery calcifications (CAC). It is not well-established, whether estimation of CAC based on this CT scan can identify patients with increased risk of major adverse cardiac events (MACE) and thus possibly improve therapy and prognosis. Purpose This study aims to assess CAC and evaluate whether high calcium scores predict the risk of MACE in patients newly diagnosed with PCa. Methods We identified 634 consecutive patients diagnosed with PCa and undergoing PSMA-PET from 2016 to 2019 in an area of 300.000 residents. In total, 63 patients were excluded due to prior revascularization. The remaining 571 patients (mean age 69.9±6.7 years) were included. Patients were followed until June 2021 or until an event occurred (mean follow-up 962±372 days). We used a standard cardiac CT software to assess CAC. Information on MACE defined as all-cause mortality, stroke and myocardial infarction were obtained from electronic patient files. We divided patients into five groups based on their coronary artery calcium score (CACS): 0–10, 11–99, 100–399, 400–999, and + 1000. Cox regression analysis was used to compute the hazard ratios (HR) for MACE with CACS 0–10 as reference while adjusting for age, hypertension diabetes, and treatment with aspirin and statins. Results We found a significantly increasing risk of MACE with increasing CACS after adjustment for risk factors. For CACS 100–399 (n=136): HR 2.10 (95% CI: 0.98–4.51, p=0.056), for CACS 400–999 (n=79): HR of 2.99 (95% CI: 1.35–6.59, p=0.007) and for CACS +1000 (n=150): HR 3.06 (95% CI: 1.37–6.85, p=0.006) (Figure 1). Cardiovascular disease prevention treatment with statins and aspirin was 53% and 16% in patients with CACS 400–999 and 52% and 19% in patients with CACS + 1000. Conclusion In patients with PCa, estimating coronary calcium score based on non-ECG-gated CT scans, which are performed as part of the diagnostic workup, predicts the occurrence of MACE. In the patient group with the highest CAC, a four-year event rate of 24% was found. In combination with the finding of infrequent use of statin and aspirin, this emphasizes the possibility of early detection of high CAC in patients with PCa and illustrates the potential for more extensive use of preventive treatment. Future studies should investigate the effect of preventive treatment being initiated in patients with PCa and high CAC. Funding Acknowledgement Type of funding sources: None.

Fully Integrated Laser Guidance for CT-Based Punctures: A Study in Phantoms and Patients

PurposeTo test the hypothesis of equal or even superior applicability and accuracy of a fully integrated, laser-based computed tomography (CT) navigation system compared with conventional CT guidance for percutaneous interventions. Materials and MethodsCT-guided punctures were first performed in phantoms. Four radiologists with different experience levels (2 residents (L.B., C.D.) and 2 board-certified radiologists (B.M., K.R.) performed 48 punctures using both conventional image-guided and laser-guided approaches. Subsequently, 12 punctures were performed in patients during a clinical pilot trial. Phantom targets required an in-plane or a single-/double-angulated, out-of-plane approach. Planning and intervention time, control scan number, radiation exposure, and accuracy of needle placement (measured by deviation of the needle tip to the designated target) were assessed for each guidance technique and compared (Mann-Whitney U test and t test). Patient interventions were additionally analyzed for applicability in a clinical setting. ResultsThe application of laser guidance software in the phantom study and in 12 human patients in a clinical setting was both technically and clinically feasible in all cases. The mean planning time (P = .009), intervention time (P = .005), control scan number (P < .001), and radiation exposure (P = .013) significantly decreased for laser-navigated punctures compared with those for conventional CT guidance and especially in punctures with out-of-plane-trajectories. The accuracy significantly increased for laser-guided interventions compared with that for conventional CT (P < .001). ConclusionsInterventional radiologists with differing levels of experience performed faster and more accurate punctures for out-of-plane trajectories in the phantom models, using a new, fully integrated, laser-guided CT software and demonstrated excellent clinical and technical success in initial clinical experiments.

A cadaveric study on the origins of the uterine artery

The uterine artery (UA) is a visceral branch from the anterior division of the internal iliac artery (IIA). Knowledge of the variant origins of this artery is critical during radiologic and surgical procedures of the pelvis, especially those involving the uterus, where managing blood flow is vital. Though its path and destination are well agreed upon, the origin of the UA differs notably, and has led many anatomists to create numerous descriptions for the distinctive variation. This project investigated the origin of the UA in the unique South Texas population of female cadavers donated to the UT Health San Antonio and established a fundamental and comprehensive classification system of the origin of this vessel which readily accommodates previous systems while improving its descriptive terminology. As the UA was identified, its origin was classified into three different ranks—primary, secondary, or tertiary. Primary‐ranked vessels originated directly from the internal iliac artery (IIA) and took three different formations as a separate branch, bifurcation with another vessel, or trifurcation with two other vessels. Secondary‐ranked UAs originated from primary vessels and tertiary‐ranked vessels originated from secondary vessels. 58.97% (23/39) of the UAs studied arose from the IIA as a primary‐ranked vessel, 38.5% (15/39) as a secondary rank, and 2.6% (1/39) as a tertiary rank. 21.7% (5/23) of primary‐ranked UAs took origin from IIA as a separate branch, 56.5% (13/23) as bifurcation with another vessel and 21.7% (5/23) as trifurcation with two other vessels. The UA originated as a bifurcation with the umbilical artery (UmbA) in 13/13 cases. UA origin as a trifurcation was observed in 3 different patterns: 40% (2/5) with the UmbA and the superior vesical artery (SVA); 40% (2/5) with the UmbA and vaginal artery (VA); 20% (1/5) with SVA and the internal pudendal artery (IPA). 93.3% (14/15) of secondary‐ranked UA arose from the UmbA and 6.7% (1/15) from the IPA. We observed a single tertiary ranked UA arising from the vaginal artery (VA), which took origin from the UmbA, a branch of the anterior division of the IIA. It is imperative that the prevalence of these primary‐ranked UA bifurcations and trifurcations be further established since permanent occlusion at the vessel’s origin may subsequently lead to necrosis of unintended tissues. Larger sample sizes amongst differing populations may lead to the discovery of uncommon bifurcation and trifurcation patterns, or with similar vessels in differing proportions. It would also be important to translate the evaluation criteria used in this study into 3D and 4D digital subtraction angiography or cone‐beam computed tomography software for clinical studies. Increasing awareness of the variant origins of the UA will ultimately improve patient treatment outcomes, particularly for female reproductive health.

PixelPrint: Three-dimensional printing of realistic patient-specific lung phantoms for CT imaging.

Phantoms are essential tools for assessing and verifying performance in computed tomography (CT). Realistic patient-based lung phantoms that accurately represent textures and densities are essential in developing and evaluating novel CT hardware and software. This study introduces PixelPrint, a 3D-printing solution to create patient-specific lung phantoms with accurate contrast and textures. PixelPrint converts patient images directly into printer instructions, where density is modeled as the ratio of filament to voxel volume to emulate local attenuation values. For evaluation of PixelPrint, phantoms based on four COVID-19 pneumonia patients were manufactured and scanned with the original (clinical) CT scanners and protocols. Density and geometrical accuracies between phantom and patient images were evaluated for various anatomical features in the lung, and a radiomic feature comparison was performed for mild, moderate, and severe COVID-19 pneumonia patient-based phantoms. Qualitatively, CT images of the patient-based phantoms closely resemble the original CT images, both in texture and contrast levels, with clearly visible vascular and parenchymal structures. Regions-of-interest (ROIs) comparing attenuation demonstrated differences below 15 HU. Manual size measurements performed by an experienced thoracic radiologist revealed a high degree of geometrical correlation between identical patient and phantom features, with differences smaller than the intrinsic spatial resolution of the images. Radiomic feature analysis revealed high correspondence, with correlations of 0.95-0.99 between patient and phantom images. Our study demonstrates the feasibility of 3D-printed patient-based lung phantoms with accurate geometry, texture, and contrast that will enable protocol optimization, CT research and development advancements, and generation of ground-truth datasets for radiomic evaluations.

Fully automated measurement of aortic root anatomy using Philips HeartNavigator computed tomography software: fast, accurate, or both?

Cardiac computed tomography (CT) is vital for safety and efficacy of transcatheter aortic valve implantation (TAVI). We aimed to determine the accuracy of fully automated CT analysis of aortic root anatomy before TAVI by Philips HeartNavigator software. This prospective, academic, single-centre study enrolled 128 consecutive patients with native aortic valve stenosis considered for TAVI. Automated HeartNavigator software was compared to the standard manual CT analysis by experienced operators using FluoroCT software. The sizing of the aortic annulus by perimeter and area significantly differed between both methods: mean perimeter was 76.43 mm vs. 77.52 mm (P < 0.0001) using manual FluoroCT vs. automated HeartNavigator software; mean area was 465 mm2 vs. 476 mm2 (P < 0.0001). Interindividual variability testing revealed mean differences between the two operators were 1.21 mm for the aortic annulus perimeter and 9 mm2 for the aortic annulus area. The hypothetical self-expandable transcatheter prosthesis sizing resulted in 80% agreement in 80% of cases. The time required to perform the automated CT analysis was significantly shorter than the time required for manual analysis (mean 17.8 min vs. 2.1 min, P < 0.0001). Philips HeartNavigator fully automated software for pre-TAVI CT analysis is a promising technology. Differences detected in aortic annulus dimensions are small and similar to the variability of manual CT analysis. Automated prediction of optimal fluoroscopic viewing angles is accurate. Correct transcatheter prosthesis sizing requires clinical oversight.

Ultrashort Echo-Time Magnetic Resonance Imaging Sequence in the Assessment of Systemic Sclerosis-Interstitial Lung Disease.

To test respiratory-triggered ultrashort echo-time (UTE) Spiral VIBE-MRI sequence in systemic sclerosis-interstitial lung disease assessment compared with computed tomography (CT). Fifty four SSc patients underwent chest CT and UTE (1.5 T). Two radiologists, independently and in consensus, verified ILD presence/absence and performed a semiquantitative analysis (sQA) of ILD, ground-glass opacities (GGO), reticulations and honeycombing (HC) extents on both scans. A CT software quantitative texture analysis (QA) was also performed. For ILD detection, intra-/inter-reader agreements were computed with Cohen K coefficient. UTE sensitivity and specificity were assessed. For extent assessments, intra-/inter-reader agreements and UTE performance against CT were computed by Lin's concordance coefficient (CCC). Three UTE were discarded for low quality, 51 subjects were included in the study. Of them, 42 QA segmentations were accepted. ILD was diagnosed in 39/51 CT. UTE intra-/inter-reader K in ILD diagnosis were 0.56 and 0.26. UTE showed 92.8% sensitivity and 75.0% specificity. ILD, GGO, and reticulation extents were 14.8%, 7.7%, and 7.1% on CT sQA and 13.0%, 11.2%, and 1.6% on CT QA. HC was <1% and not further considered. UTE intra-/inter-reader CCC were 0.92 and 0.89 for ILD extent and 0.84 and 0.79 for GGO extent. UTE RET extent intra-/inter-reader CCC were 0.22 and 0.18. UTE ILD and GGO extents CCC against CT sQA and QA were ≥0.93 and ≥0.88, respectively. RET extent CCC were 0.35 and 0.22 against sQA and QA, respectively. UTE Spiral VIBE-MRI sequence is reliable in assessing ILD and GGO extents in systemic sclerosis-interstitial lung disease patients.

Pediatric effective dose assessment for routine computed tomography examinations in Tehran, Iran.

Background:The purpose of this study is to evaluate the effective dose (ED) for computed tomography (CT) examination in different age groups and medical exposure in pediatric imaging centers in Tehran, Iran.Methods:Imaging data were collected from 532 pediatric patients from four age groups subjected to three prevalent procedures. National Cancer Institute CT (NCICT) software was used to calculate the ED value.Results:The mean ED values were 1.60, 4.16, and 10.56 mSv for patients' procedures of head, chest, and abdomen–pelvis, respectively. This study showed a significant difference of ED value among five pediatric medical imaging centers (P < 0.05). In head, chest, and abdomen–pelvis exams, a reduction in ED was evident with decreasing patients' age.Conclusion:As there were significant differences among ED values in five pediatric medical imaging centers, optimizing this value is necessary to decrease this variation. For head CT in infants and also abdomen–pelvis, further reduction in radiation exposure is required.

CT-Based Modeling of the Dentition for Craniomaxillofacial Surgical Planning.

Historically, the accuracy of imaging teeth by computed tomography (CT) has been suboptimal and deemed inadequate for surgical planning of orthognathic procedures. However, recent advances in CT hardware and software have significantly improved the accuracy of imaging occlusal anatomy. This technical note describes a quantitative means of evaluating the accuracy of CT-based modeling of teeth. Three-dimensional models of the dentition were created from a CT scan obtained of a craniomaxillofacial skeleton. Multiple reconstruction algorithms and modeling parameters were applied. The dentition of the same skeleton was scanned using a handheld optical scanning device to serve as the "gold standard." Semi-automated registrations of CT and optically acquired models were performed and deviation analysis was conducted. On average, the deviation of the CT model with the optical scan measured 0.19 to 0.25 mm across the various reconstruction and modeling parameters, with a mean of 0.22 mm. Computed tomography underestimated contours at cusp tips, while overestimating contours in occlusal groves. The use of bone reconstruction algorithms and decreased model smoothing resulted in more accurate models, though greater surface noise. Future studies evaluating the clinical effectiveness of CT-based occlusal splints should take this finding into account.

Longitudinal Study of Dental Implants in HIV-Positive Patients.

This study compared the clinical outcome of dental implants and their implant-supported restorations over a 3-year period involving patients both positive and negative for the human immunodeficiency virus. Twenty patients testing positive for the human immunodeficiency virus were recruited for this study. Twenty-one negative control patients were also selected, for a total of forty one patients. Diagnostic impressions were collected and cone beam computed tomography images were obtained. Implant size and positioning were planned using cone beam computed tomography software. Two stage or single surgery was performed as determined by the surgeon (periodontist). After a 6-month healing period, definitive impressions were fabricated using polyvinyl siloxane impression material. Implant stability quotient values were obtained at the time of surgery and placement of the restoration. Screw-retained custom titanium abutments were designed, milled, and placed with 25 N·cm torque using a calibrated torque controller. Porcelain fused-to-metal complete coverage restorations were then cemented with elastomeric resin implant cement. Implants and restorations were assessed at 6-month intervals over a period of 3 years for stability, peri-implant health, and patient satisfaction. Over the 3-year period, 25 of 42 implants placed in the negative control group were assessed, and 17 of 27 implants placed in the positive control group were evaluated. The overall patient retention rate was 77%. At the 3-year follow up, restorations examined were fully functional and causing no pain. Overall implant retention within the positive group was 96%. Implant retention within the negative control group was 100%. No differences were noted between groups for bone loss based on statistical tests. Within the limitations of this clinical investigation, the presence of human immunodeficiency virus per se was not a contraindication to dental treatment with implant-supported restorations.

Examining the morphometric features of bulbus oculi in Van cats by using computed tomography and magnetic resonance imaging

This study was conducted to obtain the morphometric and volumetric measurements of bulbus oculi of Van cats, growing around the city of Van in Turkey and named after here, by using computed tomography (CT) and magnetic resonance imaging (MRI), and to reveal the biometric differences of these measurement values between the sexes. A total of 16 adult Van cats including 8 females and 8 males were used in the study. The animals were anesthetized with the combination of xylazine and ketamine. The anesthetized animals were scanned by using CT and MRI devices and their images were obtained. Then, the morphometric and volumetric measurements of bulbus oculi were calculated from these images using the software (Syngo CT Software) in the workstation and their statistical analysis was performed. Upon the examination of the morphometric and volumetric analysis results, it was determined that while W (bodyweight) and ACL (Left Anterior Chamber) values were higher in male cats, DVLL (Dorsoventral length of the left lens) value was higher in female cats. These differences between the sexes were statistically significant (P&amp;lt;0.05). The volumetric measurement values of bulbus oculi and lens were determined to be averagely 4.60 ± 0.27 cm3 and 0.67 ± 0.09 cm3, respectively. In conclusion, the statistical differences of biometric values of bulbus oculi between male and female Van cats were determined by using CT and MRI. It is thought that the present study would contribute to the ophthalmological applications and the students receiving anatomy education.