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Quantification of Nasal Septal Deviation With Computed Tomography Data.

PubMED - sab, 06/06/2020 - 09:12
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Quantification of Nasal Septal Deviation With Computed Tomography Data.

J Craniofac Surg. 2020 Jun 04;:

Authors: Denour E, Roussel LO, Woo AS, Boyajian M, Crozier J

Abstract
BACKGROUND: Despite extensive literature on the classification and management of nasal septal deviation (NSD) for preoperative planning, standardized objective measures to evaluate the NSD severity remains challenging. In this study, we quantitatively analyzed NSD to determine the most predictive two-dimensional (2D) computed tomography (CT)-landmark for overall three-dimensional (3D) septal morphology derived from nasal airway segmentation.
METHODS: A retrospective study was conducted at a large academic center. One hundred four patients who underwent CT scans of the face were selected from a computer imaging database. Demographic variables were screened to ensure an equal number of men and women in different age groups. Digital Imaging and Communications in Medicine files were imported for 3D nasal cavity segmentation using 3D Slicer software. A volumetric analysis was performed to determine 3D NSD ratios. These values were compared to previously reported methods of obtaining objective 2D NSD measures using OsiriX and MATLAB software. Maximum deviation values were calculated using OsiriX, while the root mean square values were retrieved using MATLAB. Deviation area and curve to line ratios were both quantified using OsiriX and MATLAB.
RESULTS: The data set consisted of 52 men and 52 women patients aged 20 to 100 years (mean = 58 years, standard deviation = 23 years). There was a strong correlation between 3D NSD ratio and maximum deviation (r = 0.789, P < 0.001) and deviation area (r = 0.775, P < 0.001). Deviation area (r = 0.563, P < 0.001), root mean square (r = 0.594, P < 0.001), and curve to line ratio (r = 0.470, P < 0.001) had a positive correlation of moderate strength. The curve to line ratio was not significant (r = 0.019, P = 0.85).
CONCLUSIONS: The 2D CT-based NSD landmarks maximum deviation and deviation area were the most predictive of the severity of NSD from 3D nasal cavity segmentation. We present a robust open-source method that may be useful in predicting the severity of NSD in CT images.

PMID: 32502103 [PubMed - as supplied by publisher]

"STUDY ON PREDICTING THE IDEAL VENTRICULAR FREEHAND PASS TRAJECTORY USING OSIRIX SOFTWARE AND THE ROLE OF OCCIPITAL SHAPE VARIATIONS."

PubMED - qua, 05/27/2020 - 07:46

"STUDY ON PREDICTING THE IDEAL VENTRICULAR FREEHAND PASS TRAJECTORY USING OSIRIX SOFTWARE AND THE ROLE OF OCCIPITAL SHAPE VARIATIONS."

World Neurosurg. 2020 May 23;:

Authors: Deora H, Pruthi N, Rao KVLN, Saini J, Dikshit P

PMID: 32454198 [PubMed - as supplied by publisher]

MRI perfusion analysis using freeware, standard imaging software.

PubMED - qua, 05/20/2020 - 10:02
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MRI perfusion analysis using freeware, standard imaging software.

BMC Vet Res. 2020 May 18;16(1):141

Authors: Hartmann A, Scholz VB, Lautenschläger IE

Abstract
BACKGROUND: Perfusion-weighted imaging is only scarcely used in veterinary medicine. The exact reasons are unclear. One reason might be the typically high costs of the software packages for image analysis. In addition, a great variability concerning available programs makes it hard to compare results between different studies. Moreover, these algorithms are tuned for their usage in human medicine and often difficult to adapt to veterinary studies. In order to address these issues, our aim is to deliver a free open source package for calculating quantitative perfusion parameters. We develop an "R package" calculating mean transit time, cerebral blood flow and cerebral blood volume from data obtained with freely imaging software (OsiriX Light®). We hope that the free availability, in combination with the fact that the underlying algorithm is open and adaptable, makes it easier for scientists in veterinary medicine to use, compare and adapt perfusion-weighted imaging analysis. In order to demonstrate the usage of our software package, we reviewed previously acquired perfusion-weighted images from a group of eight purpose-breed healthy beagle dogs and twelve client-owned dogs with idiopathic epilepsy. In order to obtain the data needed for our algorithm, the following steps were performed: First, regions of interest (ROI) were drawn around different, previously reported, brain regions and the middle cerebral artery. Second, a ROI enhancement curve was generated for each ROI using a freely available PlugIn. Third, the signal intensity curves were exported as a comma-separated-value file. These files constitute the input to our software package, which then calculates the PWI parameters.
RESULTS: We used our software package to re-assess perfusion weighted images from two previous studies. The clinical results were similar, showing a significant increase in the mean transit time and a significant decrease in cerebral blood flow for diseased dogs.
CONCLUSION: We provide an "R package" for computing the main perfusion parameters from measurements taken with standard imaging software and describe in detail how to obtain these measurements. We hope that our contribution enables users in veterinary medicine to easily obtain perfusion parameters using standard Open Source software in a standard, adaptable and comparable way.

PMID: 32423403 [PubMed - in process]

Open Health Imaging Foundation Viewer: An Extensible Open-Source Framework for Building Web-Based Imaging Applications to Support Cancer Research.

PubMED - sex, 04/24/2020 - 09:18

Open Health Imaging Foundation Viewer: An Extensible Open-Source Framework for Building Web-Based Imaging Applications to Support Cancer Research.

JCO Clin Cancer Inform. 2020 Apr;4:336-345

Authors: Ziegler E, Urban T, Brown D, Petts J, Pieper SD, Lewis R, Hafey C, Harris GJ

Abstract
PURPOSE: Zero-footprint Web architecture enables imaging applications to be deployed on premise or in the cloud without requiring installation of custom software on the user's computer. Benefits include decreased costs and information technology support requirements, as well as improved accessibility across sites. The Open Health Imaging Foundation (OHIF) Viewer is an extensible platform developed to leverage these benefits and address the demand for open-source Web-based imaging applications. The platform can be modified to support site-specific workflows and accommodate evolving research requirements.
MATERIALS AND METHODS: The OHIF Viewer provides basic image review functionality (eg, image manipulation and measurement) as well as advanced visualization (eg, multiplanar reformatting). It is written as a client-only, single-page Web application that can easily be embedded into third-party applications or hosted as a standalone Web site. The platform provides extension points for software developers to include custom tools and adapt the system for their workflows. It is standards compliant and relies on DICOMweb for data exchange and OpenID Connect for authentication, but it can be configured to use any data source or authentication flow. Additionally, the user interface components are provided in a standalone component library so that developers can create custom extensions.
RESULTS: The OHIF Viewer and its underlying components have been widely adopted and integrated into multiple clinical research platforms (e,g Precision Imaging Metrics, XNAT, LabCAS, ISB-CGC) and commercial applications (eg, Osirix). It has also been used to build custom imaging applications (eg, ProstateCancer.ai, Crowds Cure Cancer [presented as a case study]).
CONCLUSION: The OHIF Viewer provides a flexible framework for building applications to support imaging research. Its adoption could reduce redundancies in software development for National Cancer Institute-funded projects, including Informatics Technology for Cancer Research and the Quantitative Imaging Network.

PMID: 32324447 [PubMed - as supplied by publisher]

Video-based augmented reality combining CT-scan and instrument position data to microscope view in middle ear surgery.

PubMED - qui, 04/23/2020 - 09:15
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Video-based augmented reality combining CT-scan and instrument position data to microscope view in middle ear surgery.

Sci Rep. 2020 Apr 21;10(1):6767

Authors: Hussain R, Lalande A, Marroquin R, Guigou C, Bozorg Grayeli A

Abstract
The aim of the study was to develop and assess the performance of a video-based augmented reality system, combining preoperative computed tomography (CT) and real-time microscopic video, as the first crucial step to keyhole middle ear procedures through a tympanic membrane puncture. Six different artificial human temporal bones were included in this prospective study. Six stainless steel fiducial markers were glued on the periphery of the eardrum, and a high-resolution CT-scan of the temporal bone was obtained. Virtual endoscopy of the middle ear based on this CT-scan was conducted on Osirix software. Virtual endoscopy image was registered to the microscope-based video of the intact tympanic membrane based on fiducial markers and a homography transformation was applied during microscope movements. These movements were tracked using Speeded-Up Robust Features (SURF) method. Simultaneously, a micro-surgical instrument was identified and tracked using a Kalman filter. The 3D position of the instrument was extracted by solving a three-point perspective framework. For evaluation, the instrument was introduced through the tympanic membrane and ink droplets were injected on three middle ear structures. An average initial registration accuracy of 0.21 ± 0.10 mm (n = 3) was achieved with a slow propagation error during tracking (0.04 ± 0.07 mm). The estimated surgical instrument tip position error was 0.33 ± 0.22 mm. The target structures' localization accuracy was 0.52 ± 0.15 mm. The submillimetric accuracy of our system without tracker is compatible with ear surgery.

PMID: 32317726 [PubMed - in process]

Introducing a new method for classifying skull shape abnormalities related to craniosynostosis.

PubMED - dom, 04/19/2020 - 08:38
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Introducing a new method for classifying skull shape abnormalities related to craniosynostosis.

Eur J Pediatr. 2020 Apr 17;:

Authors: Kronig ODM, Kronig SAJ, Vrooman HA, Veenland JF, Jippes M, Boen T, Van Adrichem LNA

Abstract
We present a novel technique for classification of skull deformities due to most common craniosynostosis. We included 5 children of every group of the common craniosynostoses (scaphocephaly, brachycephaly, trigonocephaly, and right- and left-sided anterior plagiocephaly) and additionally 5 controls. Our outline-based classification method is described, using the software programs OsiriX, MeVisLab, and Matlab. These programs were used to identify chosen landmarks (porion and exocanthion), create a base plane and a plane at 4 cm, segment outlines, and plot resulting graphs. We measured repeatability and reproducibility, and mean curves of groups were analyzed. All raters achieved excellent intraclass correlation scores (0.994-1.000) and interclass correlation scores (0.989-1.000) for identifying the external landmarks. Controls, scaphocephaly, trigonocephaly, and brachycephaly all have the peak of the forehead in the middle of the curve (180°). In contrary, in anterior plagiocephaly, the peak is shifted (to the left of graph in right-sided and vice versa). Additionally, controls, scaphocephaly, and trigonocephaly have a high peak of the forehead; scaphocephaly has the lowest troughs; in brachycephaly, the width/frontal peak ratio has the highest value with a low frontal peak.Conclusion: We introduced a preliminary study showing an objective and reproducible methodology using CT scans for the analysis of craniosynostosis and potential application of our method to 3D photogrammetry.What is Known:• Diagnosis of craniosynostosis is relatively simple; however, classification of craniosynostosis is difficult and current techniques are not widely applicable.What is New:• We introduce a novel technique for classification of skull deformities due to craniosynostosis, an objective and reproducible methodology using CT scans resulting in characteristic curves. The method is applicable to all 3D-surface rendering techniques.• Using external landmarks and curve analysis, specific and characteristic curves for every type of craniosynostosis related to the specific skull deformities are found.

PMID: 32303825 [PubMed - as supplied by publisher]

Assessing the feasibility of NaF-PET/CT versus FDG-PET/CT to detect abdominal aortic calcification or inflammation in rheumatoid arthritis patients.

PubMED - dom, 04/12/2020 - 07:30
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Assessing the feasibility of NaF-PET/CT versus FDG-PET/CT to detect abdominal aortic calcification or inflammation in rheumatoid arthritis patients.

Ann Nucl Med. 2020 Apr 10;:

Authors: Seraj SM, Raynor WY, Revheim ME, Al-Zaghal A, Zadeh MZ, Arani LS, Rojulpote C, Werner TJ, Gerke O, Høilund-Carlsen PF, Baker JF, Alavi A, Hunt SJ

Abstract
OBJECTIVE: We aimed to determine whether NaF-PET/CT or FDG-PET/CT can detect abdominal aortic molecular calcification and inflammation in patients with rheumatoid arthritis (RA).
METHODS: In this study, 18 RA patients (4 women, 14 men; mean age 56.0 ± 11.7) and 18 healthy controls (4 women, 14 men; mean age 55.8 ± 11.9) were included. The controls were matched to patients by sex and age (± 4 years). All subjects of this study underwent NaF-PET/CT scanning 90 min following the administration of NaF. FDG-PET/CT imaging was performed 180 min following intravenous FDG injection. Using OsiriX software, the global mean standardized uptake value (global SUVmean) in abdominal aorta was calculated for both FDG and NaF. The NaF SUVmean and FDG SUVmean were divided by the blood pool activity providing target-to-background ratios (TBR) namely, NaF-TBRmean and FDG-TBRmean. The CT calcium volume score was obtained using a growing region algorithm based on Hounsfield units.
RESULTS: The average NaF-TBRmean score among RA patients was significantly greater than that of healthy controls (median 1.61; IQR 1.49-1.88 and median 1.40; IQR 1.23-1.52, P = 0.002). The average CT calcium volume score among RA patients was also significantly greater than that of healthy controls (median 1.96 cm3; IQR 0.57-5.48 and median 0.004 cm3; IQR 0.04-0.05, P < 0.001). There was no significant difference between the average FDG-TBRmean scores in the RA patients when compared to healthy controls (median 1.29; IQR 1.13-1.52 and median 1.29; IQR 1.13-1.52, respectively, P = 0.98).
CONCLUSION: Quantitative assessment with NaF-PET/CT identifies increased molecular calcification in the wall of the abdominal aorta among patients with RA as compared with healthy controls, while quantitative assessment with FDG-PET/CT did not identify a difference in aortic vessel wall FDG uptake between the RA and healthy control groups.

PMID: 32277422 [PubMed - as supplied by publisher]

Comparison of 18F-sodium fluoride uptake in the whole bone, pelvis, and femoral neck of multiple myeloma patients before and after high-dose therapy and conventional-dose chemotherapy.

PubMED - dom, 04/05/2020 - 09:26
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Comparison of 18F-sodium fluoride uptake in the whole bone, pelvis, and femoral neck of multiple myeloma patients before and after high-dose therapy and conventional-dose chemotherapy.

Eur J Nucl Med Mol Imaging. 2020 Apr 03;:

Authors: Zirakchian Zadeh M, Østergaard B, Raynor WY, Revheim ME, Seraj SM, Acosta-Montenegro O, Ayubcha C, Yellanki DP, Al-Zaghal A, Nielsen AL, Constantinescu CM, Gerke O, Werner TJ, Zhuang H, Abildgaard N, Høilund-Carlsen PF, Alavi A

Abstract
AIM: To compare the effects of high-dose therapy (HDT consisting of high-dose chemotherapy followed by autologous stem cell transplantation) and conventional-dose chemotherapy (non-HDT) on the uptake of 18F-sodium fluoride (NaF) in the whole bone, pelvis, and femoral neck of multiple myeloma (MM) patients.
METHOD: The data of 19 MM patients who received HDT (61.5 (SD 5.6) years) and 11 MM patients who received conventional-dose chemotherapy (70.9 (SD 7.2) years) were collected in a prospective study. NaF PET/CT imaging was performed at baseline, and 8 weeks and 2 weeks after treatment for the HDT group and the non-HDT group, respectively. A CT-based algorithm was applied to segment the bones, and the global mean SUV (GSUVmean) of the whole bone and pelvis was calculated (OsiriX MD v.9.0, Pixmeo SARL; Bernex, Switzerland). In addition, regions of interest for the whole, medial, and lateral femoral neck were delineated bilaterally. Whole bone and pelvis measurements were replicated by two observers.
RESULTS: The average GSUVmean in the whole bone and pelvis of the patients who underwent HDT significantly decreased from before to after treatment (- 16.27%, p = 0.02 and - 16.54%, p = 0.01, respectively). A significant decrease in the whole and lateral femoral neck was also observed bilaterally in the HDT group. No significant decrease in average GSUVmean was observed in the non-HDT group. A high level of inter-observer reliability was found in intra-class correlation (ICC for pre-treatment whole bone 0.983, post-treatment whole bone 0.989, pre-treatment whole pelvis 0.998, post-treatment whole pelvis 0.996).
CONCLUSION: NaF uptake significantly decreased after treatment in patients who received high-dose therapy. A high level of agreement was observed between two operators for whole bone and pelvis measurements.

PMID: 32246208 [PubMed - as supplied by publisher]

Role of 18F-NaF-PET in assessing aortic valve calcification with age.

PubMED - sex, 03/27/2020 - 17:19
Related Articles

Role of 18F-NaF-PET in assessing aortic valve calcification with age.

Am J Nucl Med Mol Imaging. 2020;10(1):47-56

Authors: Rojulpote C, Borja AJ, Zhang V, Aly M, Koa B, Seraj SM, Raynor WY, Kothekar E, Kaghazchi F, Werner TJ, Gerke O, Høilund-Carlsen PF, Alavi A

Abstract
Aortic valve calcification is a slow and progressive pathological process that can manifest in various degrees from mild thickening of the valve known as aortic sclerosis to severe calcification that hinders the leaflet motion, known as aortic stenosis. The evolving concept of aortic calcification is thought to result from infiltration of macrophages and T-lymphocytes. Moreover, the incidence of aortic valve calcification increases with age, in particular over the age of 50. In this study, we aimed to assess 18F-sodium fluoride (18F-NaF) uptake by the aortic valve on PET/CT scans performed in two age groups; 25-35 and 50-75 years of age. We hypothesized that patients aged 50-75, comprising of both healthy and high risk for cardiovascular disease (CVD), would have higher uptake of 18F-NaF than patients aged 25-35 and further that in the former group those who were at high risk for CVD had also higher 18F-NaF uptake. The 25-35-year group comprised of 6 males and 6 females, mean age 30 ± 3.5 years, while the 50-75-year group included 18 males and 20 females, mean age 61 ± 6.2 years. All underwent PET/CT imaging 90 minutes following the injection of 2.2 MBq of 18F-NaF per kg body weight. Aortic valve analysis was performed on axial sections using standard guided computer software (OsiriX MD software, version 9.0.02). The average aortic valve SUVmean was calculated for each patient. Univariate regression models stratified by age group were employed to determine the association of SUVmean with age. In the 50-75-year group, explanatory multivariable regression modeling was applied using available demographic and baseline information. SUVmean was found to be higher in the 50-75 age group than in the 25-35 age group: 0.91 ± 0.25 and 0.86 ± 0.26, respectively. The association of SUVmean with age was much stronger in individuals aged 50-75 years (r = 0.64, P<0.001) than individuals aged 25-35 years (r = 0.20, P = 0.53). In addition, in the 50-75 age group the association was much stronger in subjects with a high risk of CVD than in individuals without: r = 0.68, P = 0.001 versus r = 0.48, P = 0.042. Furthermore, the SUVmean was found to be higher in the high-risk group aged 50-75 than in the low-risk healthy group aged 50-75: 0.98 ± 0.32 and 0.83 ± 0.13. Aortic valve 18F-NaF uptake was higher in patients belonging to the age group of 50-75 years and correlated positively with age and high risk of CVD. These data provide evidence for a potential role of 18F-NaF PET/CT in identifying calcific changes in the aortic valve and may help direct therapeutic intervention prior to the development of symptomatic valvular disease.

PMID: 32211218 [PubMed]