Precision of orthodontic cephalometric measurements on ultra low dose-low dose CBCT reconstructed cephalograms

Abstract Objectives To analyze differences in variation of orthodontic diagnostic measurements on lateral cephalograms reconstructed from ultra low dose-low dose (ULD-LD) cone beam computed tomography (CBCT) scans (RLC) as compared to variation of measurements on standard lateral cephalograms (SLC), and to determine if it is justifiable to replace a traditional orthodontic image set for an ULD-LD CBCT with a reconstructed lateral cephalogram. Material and methods ULD-LD CBCT images and SLCs were made of forty-three dry human skulls. From the ULD-LD CBCT dataset, a lateral cephalogram was reconstructed (RLC). Cephalometric landmarks (13 skeletal and 7 dental) were identified on both SLC and RLC twice in two sessions by two calibrated observers. Thirteen cephalometric variables were calculated. Variations of measurements, expressed as standard deviations of the 4 measurements on SLC and RLC, were analyzed using a paired sample t-test. Differences in the number of observations deviating ≥ 2.0 mm or degrees from the grand mean between SLC and RLC were analyzed using a McNemar test. Results Mean SDs for 7 out of 13 variables were significantly smaller for SLCs than those for RLCs, but differences were small. For 9 out of 13 variables, there was no significant difference between SLC and RLC for the number of measurements outside the range of 2 mm or degrees. Conclusions Based on the lower radiation dose and the small differences in variation in cephalometric measurements on reconstructed LC compared to standard dose LC, ULD-LD CBCT with reconstructed LC should be considered for orthodontic diagnostic purposes. Clinical relevance ULD-LD CBCT with reconstructed LC should be considered for orthodontic purposes.

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Detectability of Osseous Lesions with a Pre-Programmed Low-Dose Protocol for Cone-Beam Computed Tomography

Applied Sciences ◽

10.3390/app10144961 ◽

2020 ◽

Vol 10 (14) ◽

pp. 4961

Author(s):

Quirin Döbelin ◽

Bernd Stadlinger ◽

Daniel B. Wiedemeier ◽

Dominique Bichsel ◽

Martin Rücker ◽

...

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Low Dose ◽

Standard Dose ◽

Correct Diagnosis ◽

Three Dimensional ◽

Cone Beam ◽

Diagnostic Reliability ◽

Significant Difference ◽

User Friendly

The present study aimed to compare the diagnostic reliability of a pre-set, manufacturer-specific, low-dose mode against a standard-dose mode in the detection of four different osseous lesions in the mandible with cone-beam computed tomography (CBCT). Four types of lesions (periapical lesion, extended periodontal gap, recession of the buccal lamella, sequestrum/fracture) were prepared on 40 pig mandibles. CBCT images were obtained from each mandible, with both the low-dose and standard-dose modes using the Orthophos SL CBCT device (Dentsply-Sirona, Bensheim, Germany). Twelve assessors quantitatively (detection of lesions) and qualitatively (assessment of detectability) evaluated the CBCT images in SIDEXIS 4 (Dentsply-Sirona) using a study-specific digital examination tool. A correct diagnosis was achieved in almost 71% (LD: 70.8%; SD: 70.9%) of 1920 lesions, without a statistically significant difference between the low-dose and standard-dose mode. This finding was consistent across all four lesion types. In conclusion, while low-dose mode and standard-dose mode CBCT scans performed similarly in the detection of four prepared lesions of the mandible, the former may be a promising, user-friendly alternative method of obtaining radiation-optimized, three-dimensional images in accordance with the As Low As Diagnostically Acceptable (ALADA) principle.

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Ultra-low-dose cone-beam CT compared to standard dose in the assessment for acute fractures

Skeletal Radiology ◽

10.1007/s00256-021-03825-5 ◽

2021 ◽

Author(s):

M. C. Murphy ◽

B. Gibney ◽

J. Walsh ◽

G. Orpen ◽

E. Kenny ◽

...

Keyword(s):

Low Dose ◽

Standard Dose ◽

Cone Beam Ct ◽

Cone Beam

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Linear Mandibular Measurements: Comparison between Orthopantomograms and Lateral Cephalograms

The Cleft Palate-Craniofacial Journal ◽

10.1597/07-123.1 ◽

2009 ◽

Vol 46 (2) ◽

pp. 147-153 ◽

Cited By ~ 24

Author(s):

E. M. Ongkosuwito ◽

M. M. J. Dieleman ◽

A. M. Kuijpers-Jagtman ◽

P. G. H. Mulder ◽

J. W. van Neck

Keyword(s):

Interobserver Variability ◽

Intraclass Correlation ◽

Kappa Statistics ◽

Magnification Factor ◽

Linear Measurements ◽

Lateral Cephalogram ◽

X Ray ◽

Lateral Cephalograms ◽

Left And Right ◽

Cephalometric Measurements

Objective: To investigate the reliability of length measurements of the mandible by comparing orthopantomograms (OPTs) with lateral cephalograms. Design: Observational study. Setting: OPTs and lateral cephalograms were taken of 20 human dry skulls. Four orthodontists and four maxillofacial surgeons located landmarks on all radiographs using a computer program for cephalometric measurements. Intraobserver and interobserver variability in locating landmarks was assessed, as well as positioning of the skulls prior to radiography between the x-ray assistants. Magnification differences between the left and right side of the mandible on the OPT were determined for five skulls. Kappa statistics were used to calculate the intraclass correlation coefficient for intraobserver and interobserver differences. An F test was used to assess differences between methods and between type of observer. Results: No significant differences were found in the magnification factor of the left and right side of the mandible. Compared with a lateral cephalogram, the OPT had comparable reliability in measuring mandibular distances condylion-gonion, gonion-menton, and condylion-menton. No significant differences were observed between the x-ray assistants in taking the OPTs and lateral cephalograms or in repositioning the skulls. Significant differences were found between orthodontists and maxillofacial surgeons for landmark measurements. Conclusion: An OPT is as reliable as a lateral cephalogram for linear measurements of the mandible (condylion-gonion, gonion-menton, and condylion-menton).

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Comparative Analysis on Low- and Standard-Dose Regimes of Alteplase Thrombolytic Therapy for Acute Ischemic Stroke: Efficacy and Safety

European Neurology ◽

10.1159/000485460 ◽

2017 ◽

Vol 79 (1-2) ◽

pp. 68-73 ◽

Cited By ~ 2

Author(s):

Guangjian Zhao ◽

Tingfen Huang ◽

Mei Zheng ◽

Yansen Cui ◽

Yunyong Liu ◽

...

Keyword(s):

Ischemic Stroke ◽

Thrombolytic Therapy ◽

Acute Ischemic Stroke ◽

Dose Group ◽

Low Dose ◽

Standard Dose ◽

Efficacy And Safety ◽

Significant Difference ◽

Symptomatic Intracranial Hemorrhage ◽

Intravenous Alteplase

Objective: This study analyzed the efficacy and safety of low-dose and standard-dose alteplase intravenous thrombolytic therapy for acute ischemic stroke (AIS). Methods: Patients with AIS who underwent intravenous alteplase thrombolysis from July 2012 to December 2016 were retrospectively analyzed and correspondingly divided into low-dose (0.6–0.89 mg/kg) group and standard-dose group (0.9 mg/kg) according to alteplase dosage. The clinical outcome was evaluated by modified Rankin Scale (mRS) at 90 days after onset. The safety index was the mortality at 90 days after onset and the incidence of symptomatic intracranial hemorrhage (SICH) within 7 days. Results: A total of 1,486 patients were included (1,115 cases in low-dose group and 371 cases in standard-dose group). There were no significant differences in baseline data between the 2 groups. As mRS, good outcome rate as well as mortality rate in both groups had no significant difference (36.1 vs. 37.6%; χ2 = 10.882, p = 0.890; 5.5 vs. 7.3%; χ2 = 2.163, p = 0.076), but the incidence of SICH in low-dose group was significantly lower than that of the standard-dose group (2.2 vs. 5.9%; χ2 = 3.157, p = 0.001). Conclusion: The efficacy of low-dose alteplase intravenous thrombolytic therapy for AIS was equivalent to the standard-dose regimen but with higher safety.

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Comparison of low dose CT and standard dose Cone-beam CT for periprocedural 3D-planning of TIPSS guidance

10.1055/s-0040-1703202 ◽

2020 ◽

Author(s):

A Estler ◽

K Nikolaou ◽

R Hoffmann ◽

J Herrmann ◽

U Grosse ◽

...

Keyword(s):

Low Dose ◽

Standard Dose ◽

Cone Beam Ct ◽

Cone Beam ◽

Low Dose Ct

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Randomised, placebo-controlled, trial comparing low dose versus standard dose Lenograstim (L) following myeloablative chemotherapy (HDT) and peripheral blood progenitor cell rescue (PBPCR) for lymphoma

Journal of Clinical Oncology ◽

10.1200/jco.2006.24.18_suppl.7624 ◽

2006 ◽

Vol 24 (18_suppl) ◽

pp. 7624-7624

Author(s):

L. Nolan ◽

S. Chilton ◽

P. Lorigan ◽

R. Else ◽

P. Smith ◽

...

Keyword(s):

Hospital Stay ◽

Peripheral Blood ◽

Low Dose ◽

Standard Dose ◽

Controlled Trial ◽

White Cell Count ◽

N Recovery ◽

Antibacterial Prophylaxis ◽

Normal Peripheral Blood ◽

Significant Difference

7624 Background: This trial was performed to determine whether low-dose or standard dose L would influence recovery of haematopoiesis following HDT and PBPCR. Methods: 61 patients (pts) with non-Hodgkin lymphoma (40) or Hodgkin’s disease (21) undergoing HDT were randomised. Pts had normal peripheral blood counts prior to HDT (Hb ≥100g/L, total white cell count ≥ 3.0, neutrophils (N) ≥ 1.0 and platelets ≥ 50, and had a minimum 2.5 million CD34+ cells/kg PBPC previously collected following mobilisation with Cyclophosphamide 3g/m2 and G-CSF. All received HDT with BCNU 300mg/m2 d-7, Etoposide 200mg/m2 od d-5-d-2, Cytosine arabinoside 200mg/m2 bd d-5-d-2 and Melphalan 140mg/m2 d-1 before return of PBPC on D0. Pts were allocated standard dose L 263mcg daily (20 pts), low dose L 105mcg daily (21 pts) or placebo injections (20 pts). These commenced on day +5 following PBPCR and continued until N≥0.5. Pts received standard supportive care including prophylactic Fluconazole and Acyclovir, but not routine antibacterial prophylaxis, until haemopoietic recovery. Results: L at any dose resulted in a significantly shorter median time to N recovery ≥0.1 (10.0 vs 11.0 days, P=0.02) and ≥0.5 (11.0 vs 14.0 days, p=0.0003) compared to placebo. The only significant difference between standard- and low-dose L was in hospital stay (21.0 vs 22.0 days, p=0.04), however L at any dose showed a significant reduction over placebo (22.0 vs 23.0 days, p=0.01). Conclusions: Short course low dose L is as effective as standard dose in reducing neutrophil engraftment time following HDT and PBSCR. L at any dose reduces hospital stay when compared to placebo. This approach should be considered for those patients in whom growth factor support is indicated. Long-term follow-up data will be presented. [Table: see text] No significant financial relationships to disclose.

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Characteristics, management and response to alteplase in China versus non-China participants of the ENCHANTED trial

Stroke and Vascular Neurology ◽

10.1136/svn-2017-000085 ◽

2017 ◽

Vol 2 (2) ◽

pp. 53-58 ◽

Cited By ~ 2

Author(s):

Lily Song ◽

Xia Wang ◽

Thompson Robinson ◽

Richard I Lindley ◽

Hisatomi Arima ◽

...

Keyword(s):

Low Dose ◽

Standard Dose ◽

Artery Occlusion ◽

Lipid Lowering ◽

Large Artery ◽

Stroke Study ◽

Significant Difference ◽

Scale Scores ◽

Management Factors ◽

Artery Disease

BackgroundThe characteristics of patients with acute ischaemic stroke (AIS) and their management vary across regions, which may influence outcomes. We examined for differential patterns of outcome between China and non-China participants of the ENhanced Control of Hypertension And Thrombolysis strokE stuDy (ENCHANTED), which tested different alteplase doses in AIS.MethodsENCHANTED was an international, multicentre, open, blinded-endpoint trial of the effects of low-dose (0.6 mg/kg) versus standard-dose (0.9 mg/kg) intravenous alteplase on 90-day disability outcomes and symptomatic intracerebral haemorrhage (sICH) in 3310 patients with AIS.ResultsParticipants (n=1419, 48%) in China were younger, and more often male, hypertensive and with prior stroke and coronary artery disease, but less likely to have atrial fibrillation and use antihypertensive, antithrombotic and lipid-lowering agents, compared with non-China patients with AIS. Although China participants had more AIS due to large artery occlusion, were treated later and had differing ancillary management, there was no significant difference in 90-day modified Rankin scale scores 2–6 (55.6% vs 47.8%; OR, adjusted for baseline and management factors 0.87 (95% CI 0.71 to 1.07; p=0.20)) and risk of sICH (Safe Implementation of Thrombolysis in Stroke-Monitoring Study criteria: 1.4% vs 1.8%; p=0.12) compared with non-China participants. There was no heterogeneity in the treatment effects of low-dose versus standard-dose alteplase between China and non-China participants.ConclusionPatients with AIS recruited to the ENCHANTED trial in China had similar outcomes in response to thrombolysis treatment despite significantly differing demographic, clinical and management factors to patients with AIS in other regions.

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Is sub-mSv CT for evaluation of non-specific findings in bone scintigraphy of oncological patients feasible?

Acta Radiologica ◽

10.1177/0284185119874481 ◽

2019 ◽

Vol 61 (5) ◽

pp. 662-667 ◽

Cited By ~ 1

Author(s):

Yousuf Zakko ◽

Daniel Thor ◽

Irina Savitcheva ◽

Albert Sundvall ◽

Cecilia Wassberg ◽

...

Keyword(s):

Bone Scintigraphy ◽

Low Dose ◽

Standard Dose ◽

Observer Agreement ◽

Ct Scans ◽

Significant Shift ◽

Low Dose Ct ◽

Oncological Patients ◽

Significant Difference

Background Hybrid SPECT/CT systems allow the shortening of lead time for investigation of cancer patients, since a complementary CT for radiological characterization of focally increased isotope uptake of unclear origin in bone scintigraphy can be performed simultaneously. The use of low-dose CT (sub-mSv CT) reduces radiation dose compared to standard-dose CT and facilitates the application of complementary CT. Purpose To test the feasibility of sub-mSv CT for the characterization of non-specific findings in the bone scintigraphy of oncological patients. Material and Methods Nineteen oncological patients with a total of 50 findings of unclear origin on bone scintigraphy which required further correlation with morphologic data were included in the study. Each patient underwent two CT scan series consecutively: one low-dose CT and one standard-dose CT. The CT studies were randomized and each finding was rated by four blinded experienced radiologists. A shift in ratings between standard-dose and low-dose images were assessed using the Stuart–Maxwell chi-squared test. Inter-observer agreement and intra-observer agreement was assessed using Light’s kappa and Cohen’s kappa, respectively. Results The mean effective dose of low-dose CT scans was 0.8 mSv compared to 4.2 mSv for the standard-dose CT scans. No statistically significant shift in ratings was observed ( P = 0.62). There was no statistically significant difference in the inter-observer agreements: the values for the standard-dose and low-dose groups were 0.68 (95% confidence interval [CI] 0.57–0.79) and 0.60 (95% CI 0.47–0.72), respectively. Conclusion These results indicate that sub-mSv CT for characterization of non-specific findings in bone scintigraphy of oncological patients is feasible.

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Low-dose versus standard-dose lenograstim prophylaxis after chemotherapy: a randomized, crossover comparison.

Journal of Clinical Oncology ◽

10.1200/jco.1998.16.12.3874 ◽

1998 ◽

Vol 16 (12) ◽

pp. 3874-3879 ◽

Cited By ~ 23

Author(s):

G C Toner ◽

J D Shapiro ◽

C R Laidlaw ◽

D Rischin ◽

M J Millward ◽

...

Keyword(s):

Low Dose ◽

Crossover Trial ◽

Standard Dose ◽

Trial Methodology ◽

Significant Difference ◽

The Difference ◽

The Cost ◽

Stimulating Factor ◽

Randomized Crossover Study ◽

Grade Iii

PURPOSE Granulocyte colony-stimulating factor (G-CSF) administered prophylactically after chemotherapy reduces the duration and severity of neutropenia. This randomized crossover study was designed to assess whether a lower dose of G-CSF is as effective as a standard dose of 5 microg/kg daily. PATIENTS AND METHODS Patients who received standard-dose chemotherapy regimens expected to cause neutropenia received G-CSF (lenograstim) that started the day after chemotherapy for 14 days or until the absolute neutrophil count (ANC) recovered to greater than 10 x 10(9)/L. The lenograstim dose was randomly allocated to be 2 or 5 microg/kg daily in the first cycle of chemotherapy and crossed over to the alternate dose for the second cycle. The study was designed to accrue 40 assessable patients to provide a power of 80% to detect a difference in duration of neutropenia of 1 day. Fifty-two patients were randomized to treatment and 43 patients completed two cycles of identical chemotherapy. RESULTS There was little neutropenia irrespective of the dose used. Twenty-three patients (53%) had no grade III or IV neutropenia and 30 patients (70%) had no grade IV neutropenia. Crossover trial methodology was used to assess the difference in outcome caused by the lower dose compared with the standard dose (estimated treatment effect). There was no significant difference in the measures of neutropenia, hospitalization, or other clinical outcomes. The 95% confidence interval (one-sided) for the additional duration of neutropenia caused by the lower dose of lenograstim was 0.43 days or less for grade III or IV neutropenia and 0.34 days or less for grade IV neutropenia. CONCLUSION Lenograstim 2 microg/kg provides similar protection to 5 microg/kg against neutropenia that complicates standard-dose chemotherapy. The use of a lower dose has important implications for the cost-effectiveness of prophylactic G-CSF therapy.

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Comparative efficacy between rituximab versus conventional therapy and different dosage of rituximab in idiopathic membranous nephropathy

10.22541/au.161589993.31384782/v1 ◽

2021 ◽

Author(s):

Miaomiao Chen ◽

Gaosi Xu ◽

Xuexin Chen

Keyword(s):

Serum Albumin ◽

Membranous Nephropathy ◽

Dose Regimen ◽

Conventional Therapy ◽

Low Dose ◽

Standard Dose ◽

Cochrane Collaboration ◽

Idiopathic Membranous Nephropathy ◽

Moderate Risk ◽

Significant Difference

Abstract Objective: This study was to evaluate the efficacy of rituximab (RTX) versus conventional agents and different RTX dose regimens in the treatment of idiopathic membranous nephropathy (IMN). Methods: After systematically searched associated studies up to 1st December 2020, we performed a fixed and random-effects meta-analysis using the Stata software and evaluated the quality of included studies by the risk of bias scale of the Cochrane collaboration tool. Results: RTX had a higher total remission (TR) (OR = 2.663, 95% CI 1.361 to 5.210, P = 0.004) than conventional therapy for patients at moderate risk for lose of kidney function (pre-study proteinuria < 8 g/d), however, for patients at severe risk (pre-study proteinuria > 8 g/d), there was no significant difference in TR (OR = 0.691, 95% CI 0.064 to 7.423, P = 0.761). In RTX dose studies, standard dose regimen had a better effect of reducing proteinuria than low-dose regimen (Low dose MD = -3.999, 95% CI -6.177 to -1.820; standard dose MD = -5.220, 95% CI -7.160 to -3.279, P < 0.0001). Significant improvement in serum albumin was seen in patients treated with standard dose than low dose regimen (Low dose MD = 0.601, 95% CI 0.052 to 1.150, P = 0.032; standard dose MD = 0.963, 95% CI 0.740 to 1.185, P < 0.0001). Conclusion: For patients with moderate risk IMN, RTX treatment has a higher TR than conventional therapy. Standard dose RTX is more effective than low dose in reducing proteinuria and recovering serum albumin levels.

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