scholarly journals An optimized imaging protocol for [99mTc]Tc-DPD scintigraphy and SPECT/CT quantification in cardiac transthyretin (ATTR) amyloidosis

2021 ◽  
Author(s):  
Imke Schatka ◽  
Anne Bingel ◽  
Franziska Schau ◽  
Stephanie Bluemel ◽  
Daniel R. Messroghli ◽  
...  
Keyword(s):  
Field Of View ◽  
Imaging Protocol ◽  
Attr Amyloidosis ◽  
Visual Scoring ◽  
Cardiac Phantom ◽  
Phantom Measurements ◽  
Planar Images ◽  
Sensitivity Specificity ◽  
Additional Value ◽  
Detector Angle

Abstract Background In [99mTc]Tc-DPD scintigraphy for myocardial ATTR amyloidosis, planar images 3 hour p.i. and SPECT/CT acquisition in L-mode are recommended. This study investigated if earlier planar images (1 hour p.i.) are beneficial and if SPECT/CT acquisition should be preferred in H-mode (180° detector angle) or L-mode (90°). Methods In SPECT/CT phantom measurements (NaI cameras, N = 2; CZT, N = 1), peak contrast recovery (CRpeak) was derived from sphere inserts or myocardial insert (cardiac phantom; signal-to-background ratio [SBR], 10:1 or 5:1). In 25 positive and 38 negative patients (reference: endomyocardial biopsy or clinical diagnosis), Perugini scores and heart-to-contralateral (H/CL) count ratios were derived from planar images 1 hour and 3 hour p.i. Results In phantom measurements, accuracy of myocardial CRpeak at SBR 10:1 (H-mode, 0.95-0.99) and reproducibility at 5:1 (H-mode, 1.02-1.14) was comparable for H-mode and L-mode. However, L-mode showed higher variability of background counts and sphere CRpeak throughout the field of view than H-mode. In patients, sensitivity/specificity were ≥ 95% for H/CL ratios at both time points and visual scoring 3 hour. At 1 hour, visual scores showed specificity of 89% and reduced reader’s confidence. Conclusions Early DPD images provided no additional value for visual scoring or H/CL ratios. In SPECT/CT, H-mode is preferred over L-mode, especially if quantification is applied apart from the myocardium.

scholarly journals Coronal STIR sequence, a simple adjustment to routine MRI protocol for extra-spinal sciatica and sciatica-like symptoms

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Rania Zeitoun ◽  
Mohammed Saleh Ali Mohieddin
Keyword(s):  
Young Adults ◽  
Soft Tissue ◽  
Mr Imaging ◽  
Age Groups ◽  
Field Of View ◽  
Mri Protocol ◽  
Stir Sequence ◽  
Tissue Abnormalities ◽  
Additional Value ◽  
Bone Abnormalities

Abstract Background The value of adding coronal STIR images to MR imaging of sciatica aiming to detect extra-spinal abnormalities. Results Additional coronal STIR images detected extra-spinal abnormalities in 20% of the patients, thereby downgraded the normal studies from 21 to 13%. The extra-spinal abnormalities included bone abnormalities (36.4%), soft tissue abnormalities (4.5%), neurological abnormalities (2.3%), gynecological abnormalities (50%), and miscellaneous (6.8%). In 6.9% of patients, the extra-spinal abnormalities explained the patients’ pain and influenced their management. Extra-spinal causes of pain significantly correlated to positive trauma and neoplasm history, normal routine protocol images, and absent nerve root impingement. Extra-spinal abnormalities were more prevalent in age groups (20–39 years). Conclusion Coronal STIR images (field of view: mid abdomen to the lesser trochanters) identify extra-spinal abnormalities that maybe overlooked on routine MRI protocol. It is of additional value in young adults, trauma, neoplasm, and negative routine images.

scholarly journals Non-contact smartphone-based fundus imaging compared to conventional fundus imaging: a low-cost alternative for retinopathy of prematurity screening and documentation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maximilian W. M. Wintergerst ◽  
Michael Petrak ◽  
Jeany Q. Li ◽  
Petra P. Larsen ◽  
Moritz Berger ◽  
...  
Keyword(s):  
Retinopathy Of Prematurity ◽  
Low Cost ◽  
Cost Effective ◽  
Field Of View ◽  
Fundus Examination ◽  
Fundus Imaging ◽  
Examination Time ◽  
Sensitivity Specificity ◽  
Rop Screening ◽  
Good Agreement

AbstractRetinopathy of prematurity (ROP) is a frequent cause of treatable childhood blindness. The current dependency of telemedicine-based ROP screening on cost-intensive equipment does not meet the needs in economically disadvantaged regions. Smartphone-based fundus imaging (SBFI) allows for affordable and mobile fundus examination and, therefore, could facilitate cost-effective telemedicine-based ROP screening in low-resources settings. We compared non-contact SBFI and conventional contact fundus imaging (CFI) in terms of feasibility for ROP screening and documentation. Twenty-six eyes were imaged with both SBFI and CFI. Field-of-view was smaller (ratio of diameters, 1:2.5), level of detail was equal, and examination time was longer for SBFI as compared to CFI (109.0 ± 57.8 vs. 75.9 ± 36.3 seconds, p < 0.01). Good agreement with clinical evaluation by indirect funduscopy was achieved for assessment of plus disease and ROP stage for both SBFI (squared Cohen’s kappa, 0.88 and 0.81, respectively) and CFI (0.86 and 0.93). Likewise, sensitivity/specificity for detection of plus disease and ROP was high for both SBFI (90%/100% and 88%/93%, respectively) and CFI (80%/100% and 100%/96%). SBFI is a non-contact and low-cost alternative to CFI for ROP screening and documentation that has the potential to considerably improve ROP care in middle- and low-resources settings.

scholarly journals Ovarian Malignancy Prediction by Gatot Purwoto (GP) Score, Risk Malignancy Index (RMI), and Frozen Section in Young Age

2016 ◽  
Author(s):  
Liva Wijaya
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Scoring System ◽  
Frozen Section ◽  
Diagnostic Value ◽  
Young Age ◽  
Ovarian Malignancy ◽  
Aged Patients ◽  
Sensitivity Specificity ◽  
Additional Value

Objective: To know the diagnostic value of a scoring system taken before surgery and frozen section in young-aged patients with suspected malignancy. Using that result, we can also investigate whether frozen section gives additional value to clinical scoring system. Method: This study is a diagnostic test. This study was carried out by accessing RSCM’s medical record from 2006-2011. From 437 patients suspected of ovarian malignancy, we included 157 patients due to age. Result: Diagnostic value of GP score are 77%, 49%, 61%, 68%, 63%, while RMI are 69%, 49%, 58%, 45%, 59%, (sensitivity, specificity, positive predictive value, negative predictive value, and accuracy respectively). Diagnostic value of frozen section in patients with suspected malignancy using GP score >4 are 81.7%, 87.2%, 90.7%, 75.6%, 83%, while in patients with RMI 200 are 81%, 87%, 89%, 77%, 83% (sensitivity, spesificity, positive predictive value, negative predictive value, and accuracy respectively). Conclusion: Gatot Purwoto score and RMI have good diagnostic value in proving malignancy in young age. Its predictive value will be increased by frozen section. [Indones J Obstet Gynecol 2014; 3: 157-161] Keywords: frozen section, gatot purwoto score, ovarian malignancy, RMI, young age

Influence of size of field of view (FOV), position within the FOV, and scanning mode on the detection of root fracture and observer’s perception of artifacts in CBCT images

2021 ◽  
pp. 20200563
Author(s):  
Martina Gerlane de Oliveira Pinto ◽  
Saulo L. Sousa Melo ◽  
Fernanda Clotilde Mariz Suassuna ◽  
Luiz Eduardo Marinho ◽  
José Bruno da Silva Leite ◽  
...  
Keyword(s):  
Lateral Position ◽  
Field Of View ◽  
Central Position ◽  
High Definition ◽  
Chi Square ◽  
Root Fracture ◽  
Exact Test ◽  
Level Of Significance ◽  
Sensitivity Specificity ◽  
Higher Sensitivity

Objective: To assess the influence of field of view (FOV) size, scanning position within the FOV and scanning mode on the detection of root fracture and artifact perception. Methods: Forty single-rooted premolars restored with NiCr and AgPd posts were divided into two groups: fractured and sound. All teeth were scanned using four CBCT scanning protocols varying FOV sizes (80 × 80 mm and 50 × 55 mm) and scanning modes (Standard and High Definition). The sample was positioned within the FOV in two pre-set positions (central and lateral) and in four positions established by the operator (quadrants). Detection of root fracture and artifact perception were assessed by two observers using 5-point and 4-point scales. Sensitivity, specificity, accuracy, and AUC values were calculated and compared by ANOVA two-way and Tukey’s test. Chi-square and Fisher’s exact test were used to assess artifact perception. The level of significance was set at p < 0.05. Results : The central position within the FOV presented higher sensitivity, specificity, accuracy, and AUC values and differed from the lateral position within the FOV for the studied metal posts (p<0.05). Quadrant 2 presented the best sensitivity, accuracy, and AUC values (p<0.05). The lateral position within the FOV, AgPd posts, quadrants 1 and 3 and protocols 1 (SM, 80 × 80) and 2 (HD, 80× 80) presented higher frequency of artifacts classified as “severe”. Conclusion: Positioning the object in the center or closer to the anterior periphery of the FOV while using a small FOV improved the detection of root fracture and decreased artifact perception.

scholarly journals IAEA survey of dental cone beam computed tomography practice and related patient exposure in nine Central and Eastern European countries

2020 ◽  
Vol 49 (1) ◽  
pp. 20190157
Author(s):  
Adnan Beganović ◽  
Olivera Ciraj-Bjelac ◽  
Iliya Dyakov ◽  
Vesna Gershan ◽  
Ivana Kralik ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Maxillofacial Surgery ◽  
Interquartile Range ◽  
Field Of View ◽  
Cone Beam ◽  
Imaging Method ◽  
Patient Exposure ◽  
Imaging Protocol ◽  
Technical Parameters ◽  
Clinical Indications

Objectives: Cone beam CT (CBCT) in dentistry and maxillofacial surgery is a widely used imaging method for the assessment of various maxillofacial and dental pathological conditions. The objective of this study was to summarize the results of a multinational retrospective–prospective study that focused on patient exposure in this modality. Methods: The study included 27 CBCT units and 325 adult and paediatric patients, in total. Data on patients, clinical indications, technical parameters of exposure, patient dose indicator, or, alternatively, dose to phantom were collected. The dose indicator used was air kerma–area product, PKA. Results: In most scanners operators are offered with a variety of options regarding technical parameters, especially the field of view size. The median and the third quartile value of PKA for adult patients in 14 different facilities were 820 mGy cm² and 1000 mGy cm² (interquartile range = 1058 mGy cm²), and 653 mGy cm² and 740 mGy cm² (interquartile range = 1179 mGy cm²) for children, as reported by four different institutions. Phantom dose data were reported from 15 institutions, and median PKA ranged from 125 mGy cm² to 1951 mGy cm². Median PKA values varied by more than a 10-fold between institutions, mainly due to differences in imaging protocol used, in particular field of view and tube current-exposure time product. Conclusions: The results emphasize the need for a cautious approach to using dental CBCT. Imaging only when the clinical indications are clear, accompanied with the appropriate radiographic techniques and the optimum imaging protocol, will help reduce radiation dose to patients.

scholarly journals Technetium-99m scintimammography in the diagnosis of malignant breast tumors

2004 ◽  
Vol 61 (1) ◽  
pp. 35-40
Author(s):  
Ljiljana Jaukovic
Keyword(s):  
Gamma Camera ◽  
Breast Disease ◽  
Field Of View ◽  
Large Field ◽  
Imaging Method ◽  
Diagnostic Reliability ◽  
Technetium 99M ◽  
99Mtc Tetrofosmin ◽  
Malignant Breast ◽  
Sensitivity Specificity

Background. Technetium-99m (99mTc) tetrofosmin scintigraphy is a new imaging method for the diagnosis of various malignancies, such as lung, thyroid, and most frequently breast neoplasms. The aim of this study was to evaluate the diagnostic reliability of 99mTc-Tetrofosmin breast scintigraphy in the detection of malignant breast disease. Methods. 99mTc -Tetrofosmin scintimammography (SMM) was performed in 28 patients with 30 breast lesions suspicious for malignancy. Standard mammography (MM) was also done. After surgery, the results of SMM and MM were compared to definitive histopathological findings as the "gold standard". After intravenous injection of radiotracer, SMM was performed in prone and supine views of the thorax, using large field-of-view Gamma camera. Results. The results of SMM were interpreted visually and semiquantitatively, and evaluated as positive or negative. Sensitivity, specificity and accuracy, positive (PPV) and negative predictive value (NPV) were obtained in relation to histopathology. After comparing the results of SMM and MM, SMM was proved more sensitive (95% for SMM vs. 80% for MM), while the specificity of both methods was similar. Conclusion. The results of this study indicate that the contribution of SMM as a nuclear medicine procedure has its place in the diagnostic protocol for patients suspected of malignant breast cancer.

scholarly journals Are Optimised CBCT Protocols Suitable to Detect Simulated Vertical Root Fracture in the Presence of Metal Outside and/or Inside the Fov?

2021 ◽  
Author(s):  
Amanda Pelegrin Candemil ◽  
Benjamin Salmon ◽  
Karla F Vasconcelos ◽  
Anne C Oenning ◽  
Reinhilde Jacobs ◽  
...  
Keyword(s):  
High Frequency ◽  
Cone Beam Ct ◽  
Field Of View ◽  
Cone Beam ◽  
Metallic Materials ◽  
Point Scale ◽  
Root Fracture ◽  
Vertical Root Fracture ◽  
Dose Optimisation ◽  
Sensitivity Specificity

Abstract Dose optimisation has been revisited in the literature due to the high frequency of cone-beam CT (CBCT) scans and, the reduction of the field-of-view (FOV) size has shown to be an effective strategy. However, small FOV scans have negative influences of the truncation effect from the exomass.The aim of this study was to evaluate the diagnostic accuracy of an optimised CBCT protocol for the detection of simulated vertical root fracture (VRF) in the presence of metallic artefacts from the exomass and/or endomass.Twenty teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in a human mandible, metallic materials were placed in the exomass and/or endomass, and CBCT scans were obtained at two dose protocols: standard and optimised. Three radiologists evaluated the images and indicated the presence of VRF using a 5-point scale. Sensitivity, specificity and area under the ROC curve (AUC) were obtained and compared using ANOVA (α=0.05). Overall, sensitivity, specificity and AUC did not differ significantly (p>0.05) between the dose protocols.In conclusion, optimised protocols should be considered in the detection of simulated VRF irrespective of the occurrence of artefacts from metallic materials in the exomass and/or endomass.

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker
Keyword(s):  
High Resolution ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Field Of View ◽  
Small Field ◽  
High Resolution Analysis ◽  
Ccd Observations ◽  
Resolution Analysis ◽  
Very High ◽  
Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

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