Standard Scan Research Articles

Focused, low tube potential, coronary calcium assessment prior to coronary CT angiography: A prospective, randomized clinical trial

Coronary artery calcium (CAC) scanning is commonly performed before coronary CT angiography (CTA) based partly on its potential to influence CTA scan parameters. Encompassing the whole heart and performed at high tube potential (120​kVp), standard (Agatston) CAC scanning adds to patient radiation exposure. Most CAC exists in the proximal and mid coronary segments and is easily visualized at low kVp. We tested the impact of a modified calcium scan on coronary CTA acquisition decision-making and image quality in a randomized clinical trial. Providers documented planned CTA acquisition parameters prior to CAC scanning in a blinded manner. Standard Agatston CAC scans proceeded in typical fashion whereas modified scans utilized 80​kVp and reduced z-axis length focused on the proximal-to-mid coronary arteries. CTA providers reviewed the CAC burden then documented final acquisition parameters. The study included 172 patients (48% female; mean age 59​±​6.7). As planned, the calcium scan effective dose was significantly lower in the modified CAC scan group (0.14 vs. 0.74​mSv using a 0.014 k-factor or 0.26 vs. 1.38​mSv using a 0.026 k-factor; both p​<​0.001). Initially selected CTA parameters were changed at an identical rate following visual CAC assessment (59%). There was no significant difference in coronary CTA image quality (median quality score​=​4 in both groups, p​=​0.26), noise (31.0 vs 31.4 HU; p​=​0.81), or signal/noise ratio (17.9 vs 16.8; p​=​0.26). A low-kVp scan with focused field-of-view provides actionable information regarding the presence and severity of CAC prior to coronary CTA. Coronary CTA parameters based on patient variables are frequently modified after assessing CAC burden in the CTA suite. CLINICALTRIALS. NCT02972242.

Testosterone, estradiol and 25-hydroxyvitamin D effects at the proximal femur in 3D analysis from a standard 2D DXA scans of adult men

Testosterone, estradiol and 25-hydroxyvitamin D effects at the proximal femur in 3D analysis from a standard 2D DXA scans of adult men

Validation of a Telemedicine Quality Assurance Method for Point-of-Care Obstetric Ultrasound Used in Low-Resource Settings.

A remote quality assurance and improvement protocol for point-of-care obstetric ultrasound in low-resource areas was validated against the standard of care for obstetric ultrasound in the United States. Compressed movie clip ultrasound images (obstetric sweep protocol) obtained by minimally trained personnel were read and interpreted by physicians with training in obstetric ultrasound. Observed findings were compared among readers and between each reader and the gold standard ultrasound scan report. Descriptive statistics were used for the analysis. The agreements among readers and between readers and the gold standard, for the anterior and posterior variables of the placental location were excellent, with Cohen κ values of 0.81 to 0.88 and 0.77 to 0.9, respectively. Cohen κ values were slight or slight/fair for other placental locations (left, right, fundal, and low), and the sensitivity and specificity ranged widely. The agreement among readers and between readers and the gold standard for fetal number comparisons was also excellent, with Cohen κ values ranging from 0.82 to 1, sensitivity from 0.83 to 1, and specificity from 0.99 to 1. The agreement among readers for fetal presentation comparisons, according to the Cohen κ, ranged from 0.79 to 0.85 and between readers and the gold standard had values of 0.43 to 0.49. For biometric parameters and estimated gestational age calculations based on these parameters, inter-reader reliability ranged from 0.79 to 0.85 for all parameters except femur length. Greater than 94% of obstetric sweep protocol ultrasound ages were within 7 days of the corresponding gold standard age. Movie clip ultrasound images provided adequate information for remote readers to reliably determine the placental location, fetal number, fetal presentation, and pregnancy dating.

Advanced CT visualization improves the accuracy of orthopaedic trauma surgeons and residents in classifying proximal humeral fractures: a feasibility study.

Osteosynthesis of proximal humeral fractures remains challenging with high reported failure rates. Understanding the fracture type is mandatory in surgical treatment to achieve an optimal anatomical reduction. Therefore, a better classification ability resulting in improved understanding of the fracture pattern is important for preoperative planning. The purpose was to investigate the feasibility and added value of advanced visualization of segmented 3D computed tomography (CT) images in fracture classification. Seventeen patients treated with either plate-screw-osteosynthesis or shoulder hemi-prosthesis between 2015 and 2019 were included. All preoperative CT scans were segmented to indicate every fracture fragment in a different color. Classification ability was tested in 21 orthopaedic residents and 12 shoulder surgeons. Both groups were asked to classify fractures using three different modalities (standard CT scan, 3D reconstruction model, and 3D segmented model) into three different classification systems (Neer, AO/OTA and LEGO). All participants were able to classify the fractures more accurately into all three classification systems after evaluating the segmented three-dimensional (3D) models compared to both 2D slice-wise evaluation and 3D reconstruction model. This finding was significant (p < 0.005) with an average success rate of 94%. The participants experienced significantly more difficulties classifying fractures according to the LEGO system than the other two classifications. Segmentation of CT scans added value to the proximal humeral fracture classification, since orthopaedic surgeons were able to classify fractures significantly better into the AO/OTA, Neer, and LEGO classification systems compared to both standard 2D slice-wise evaluation and 3D reconstruction model.

68 Ga-PSMA-PET/CT helps to select patients for salvage radical prostatectomy with local recurrence after primary radiotherapy for prostate cancer.

To investigate the diagnostic performance of gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography (68 Ga-PSMA PET/CT) in patients with recurrent prostate cancer with regard to the presence of lymph node metastases (LNM) and local recurrences after primary radiotherapy. We retrospectively reviewed 142 patients following salvage radical prostatectomy (sRP), 50 of which had a 68 Ga-PSMA PET/CT performed as a preoperative staging module. Predictive clinical parameters were analysed in a multivariate Cox regression analysis. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) and the accuracy of 68 Ga-PSMA PET/CT were analysed with regard to LNM and local recurrence. In all, 613 lymph nodes were resected in 40 patients and 23 lymph nodes had metastatic deposits in 14 patients. In all patients local recurrence could have been found with 68 Ga-PSMA PET/CT. Sensitivity, specificity, PPV and NPV and accuracy on a per lymph node basis were 34.78% (16.38-57.2%), 100% (99.38-100%), 100%, 97.52% (96.69-98.15%) and 97.55% (96.00-98.62%). For detecting local recurrence, the sensitivity and PPV were both 100% with an accuracy of 100% (92.89-100%). 68 Ga-PSMA PET/CT should be the standard imaging in biochemical recurrent prostate cancer. With this imaging module one detects first local recurrence and can detect locoregional and distant metastases more precisely than standard CT and bone scan.

Reliability of radiological indices in comparison with dual energy x-ray absorptiometry in diagnosis of osteoporosis: A cross-sectional study

Background: Osteoporosis projects a dominant issue related to health in the community in developing country like ours –India and is often unrecognised or undiagnosed. Early Diagnosis and treatment of osteoporosis is of utmost importance. This study evaluates the accuracy of Radiological Indices in comparison to gold standard DEXA scan for diagnosis of osteoporosis, so that diagnosis of Osteoporosis can be done using simple radiographs which would be cost effective and less exposure to radiation. Methods and Material: The is study is a one year hospital based comparative study which included a total of 80 patients who presented to OPD / IPD of Department of Orthopaedics and met the inclusion criteria were enrolled in the study. Patients were subjected to DEXA scan and a plain radiograph of either of the hip joint with full length femur in AP and Lateral views. Subsequently, the Singh’s Index, Cortical Thickness Index(CTI) AP and Lateral, Calcar to Canal Ratio (CCR) were measured and compared with the standard DEXA scan. Statistical analysis used: Spearman’s Rank co-efficient was used to find correlation between Radiological Indices and DEXA scan, Kappa Statistics for level of agreement, Sensitivity and Specificity for Radiological Indices was calculated. Results: The data analysed showed significant correlation (Spearman co-efficient) between Radiological Indices and DEXA scan. Cortical thickness index Antero-posterior view and Lateral view with cut-off 0.43(r=0.8172, p< 0.0001 and r=0.8243, p< 0.0001 respectively), calcar to canal ratio with cut-off 0.50 (r=0.8188, p< 0.0001). Similarly for Singh’s Index (r=0.6002, p< 0.0001). Conclusion: Radiological indices are reliable in the diagnosis of Osteoporosis and have a good correlation with T scores decuded by DEXA scan.

Opportunistic muscle measurements on staging chest CT for extremity and truncal soft tissue sarcoma are associated with survival.

Computed tomography (CT) measurements of sarcopenia have been proposed as biomarkers associated with outcomes in various cancers and have typically been evaluated at the L3 vertebral level. However, staging imaging for patients with extremity and truncal soft tissue sarcoma (STS) often only includes chest CT imaging which precludes evaluation at L3. Therefore, we sought to evaluate muscle metrics at T12 on standard staging chest CT scans and evaluate for correlation with overall and event-free survival in patients with STS. CT chest imaging for 89 patients with intermediate and high-grade STS (53 male, 36 female; 58.5 ± 19.0 years old, follow-up 37.4 ± 27.1 months) was reviewed on PACS at T12 for skeletal muscle density (SMD) and skeletal muscle index (SMI). Overall survival increased with increased SMD on univariate (hazard ratio [HR] = 0.61 [0.43, 0.86]) and age-adjusted analysis (HR = 0.65 [0.42, 0.89]. Event-free survival also increased with increased SMD in univariate analyses (HR = 0.68 [0.49, 0.95]) but did not maintain significance after adjusting for age (HR = 0.68 [0.43, 1.07]). SMI was not a predictor of overall or event-free survival. Higher SMD measured on routinely obtained staging chest CTs in STS patients is associated with improved survival.

Impact of Scan Tilt on Quantitative Assessments Using Optical Coherence Tomography Angiography.

PurposeTo investigate the impact of scan tilt on quantitative assessments using swept-source optical coherence tomography angiography (SS-OCTA) in healthy participants.MethodsHealthy participants were imaged with a SS-OCTA system (PLEX Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA). After a standard scan was obtained, tilted scans were obtained by moving the optical coherence tomography beam entrance position horizontally. The tilting angle was measured from the B-scan image, and the flattest (horizontal) and the most tilted images were selected for comparative analysis. Foveal avascular zone (FAZ) area, vessel density (VD), and vessel length density (VLD) from the superficial and deep retinal capillary plexus (SCP, DCP), and choriocapillaris flow deficits (CC FDs) were computed and compared between horizontal and tilted images.ResultsThirteen eyes were excluded due to poor image quality or small angle difference (<8°) between the horizontal and tilted images. A final cohort of 27 normal eyes of 17 participants with a mean age of 39.3 ± 5.9 years was eligible for analysis. The FAZ area, VD, and VLD of both SCP and DCP were not significantly different between horizontal and tilted images. The CC FD, however, was significantly higher in horizontal images compared with tilted images (21.65% ± 2.41% vs. 21.06% ± 2.19%, P = 0.005).ConclusionsCC FD measurements may be significantly affected by the position of the scanning beam and resultant scan tilting. These findings highlight the importance of capturing on-axis (pupil-centered) scans for quantitative OCTA analyses.Translational RelevanceBy assessing what impact a titled scan can have on OCTA measurements, this study will aid clinicians in understanding how to interpret their results in this situation.

USE OF ULTRASONOGRAPHY IN REDUCTION OF ISOLATED ZYGOMATIC ARCH FRACTURE

Background: Isolated zygomatic arch fractures, managed by closed methods, can be inadequate leading to facial asymmetry. Assessment of the reduction and ensuring correct alignment of frac­tured fragments in the operation table always avoids next surgery. This study aims to determine intraoperative, adequacy of reduction of by use of ultrasound in isolated zygomatic arch fracture.&#x0D; Methods: During the closed reduction of isolated zygomatic arch linear probe of ultrasound was used to check the continuity of the echogenic line. The intraoperative ultrasound finding was com­pared with the gold standard CT scan.&#x0D; Results: Ultrasound has 100% sensitivity and 80 % specificity. It also has high precision and accu­racy to determine the reduction of the fractured bone.&#x0D; Conclusions: Ultrasound is a handy tool in the reduction of zygomatic arch fracture. It not only shows but also guides to adequate reduction.

Use of ultrasonography in reduction of isolated zygomatic arch fracture

Background: Isolated zygomatic arch fractures, managed by closed methods, can be inadequate leading to facial asymmetry. Assessment of the reduction and ensuring correct alignment of frac­tured fragments in the operation table always avoids next surgery. This study aims to determine intraoperative, adequacy of reduction of by use of ultrasound in isolated zygomatic arch fracture.&#x0D; Methods: During the closed reduction of isolated zygomatic arch linear probe of ultrasound was used to check the continuity of the echogenic line. The intraoperative ultrasound finding was com­pared with the gold standard CT scan.&#x0D; Results: Ultrasound has 100% sensitivity and 80 % specificity. It also has high precision and accu­racy to determine the reduction of the fractured bone.&#x0D; Conclusions: Ultrasound is a handy tool in the reduction of zygomatic arch fracture. It not only shows but also guides to adequate reduction.

Combining analysis of multi-parametric MR images into a convolutional neural network: Precise target delineation for vestibular schwannoma treatment planning.

Manual delineation of vestibular schwannoma (VS) by magnetic resonance (MR) imaging is required for diagnosis, radiosurgery dose planning, and follow-up tumor volume measurement. A rapid and objective automatic segmentation method is required, but problems have been encountered due to the low through-plane resolution of standard VS MR scan protocols and because some patients have non-homogeneous cystic areas within their tumors. In this study, we retrospectively collected multi-parametric MR images from 516 patients with VS; these were extracted from the Gamma Knife radiosurgery planning system and consisted of T1-weighted (T1W), T2-weighted (T2W), and T1W with contrast (T1W + C) images. We developed an end-to-end deep-learning-based method via an automatic preprocessing pipeline. A two-pathway U-Net model involving two sizes of convolution kernel (i.e., 3 × 3 × 1 and 1 × 1 × 3) was used to extract the in-plane and through-plane features of the anisotropic MR images. A single-pathway model that adopted the same architecture as the two-pathway model, but used a kernel size of 3 × 3 × 3, was also developed for comparison purposes. In addition, we used multi-parametric MR images with different image contrasts as the model training input in order to effectively segment tumors with solid as well as cystic parts. The results of the automatic segmentation demonstrated that (1) the two-pathway model outperformed single-pathway model in terms of dice scores (0.90 ± 0.05 versus 0.87 ± 0.07); both of them having been trained using the T1W, T1W + C and T2W anisotropic MR images, (2) the optimal single-parametric two-pathway model (dice score: 0.88 ± 0.06) was then trained using the T1W + C images, and (3) the two-pathway models trained using bi-parametric (T1W + C and T2W) and tri-parametric (T1W, T2W, and T1W + C) images outperformed the model trained using the single-parametric (T1W + C) images (dice scores: 0.89 ± 0.05 and 0.90 ± 0.05, respectively, larger than 0.88 ± 0.06) because it showed improved segmentation of the non-homogeneous parts of the tumors. The proposed two-pathway U-Net model outperformed the single-pathway U-Net model when segmenting VS using anisotropic MR images. The multi-parametric models effectively improved on the defective segmentation obtained using the single-parametric models by separating the non-homogeneous tumors into their solid and cystic parts.

The Role of Rapid Prototyping for Surgical Planning In A Case of Caval Thrombosis from Kidney Carcinoma

Aim: To define the impact of rapid prototyping for surgical planning in the surgeon’s decision-making process when dealing with a very complex clinical scenario. Method &amp; framework: A straightforward questionnaire involving four simple questions regarding specific technical aspects was administered to the surgeons to evaluate their basic judgments on the surgical strategy to follow. Images from a standard CT scan were used for the subsequent processing and 3D printing of a very cheap anatomical model of a surgical scenario with a low-cost printer, which was shared with the surgeons. At last, the same questionnaire was re-administered to the surgeons. The degree of judgment was found to be modified by approximately 25%. Conclusion: From a surgical point of view, the interaction with technical experts seems to add precious information to the clinical pre-surgical scenario for decision making. Nevertheless, 3D printing was judged too slow for routine adoption.

Using 3D Imaging Technology to Accurately Collect Postmortem Anthropometric Measurements in Children Under 5 Years of Age

Abstract Objectives The Child Health and Mortality Prevention Surveillance Network (CHAMPS) aims to identify causes of under-5 mortality in sub-Saharan African and South Asian surveillance sites. To address challenges in postmortem nutritional assessment, we evaluated anthropometry training and 3D imaging in the CHAMPS Kenya site. Methods Staff were trained using World Health Organization (WHO) recommended standard anthropometry equipment as well as 3D imaging to collect postmortem measurements. Following the training, 76 cases were measured in duplicate using standard anthropometry and 3D imaging and were compared to 75 pre-intervention cases. Outcomes included data quality metrics [standard deviations (SD), digit preference, % biologically implausible values (BIV, Length-for-age z-score (LAZ) BIV = ± 6 SD), measurement reliability (technical errors of measurement, TEM), and accuracy (correlation coefficients and Bland Altman plots of standard vs. 3D scan measurements). We used both WHO growth standard and internal standardization to produce sex and age-specific LAZ. Results Standard anthropometry data quality improved as indicated by digit preference (all measures rounded to 0.0 or 0.5 pre-intervention vs. no preference post-intervention). When using the WHO growth standards, we observed increases between pre- and post-training LAZ SD (2.55 vs. 2.92) and % BIV (5.33 vs. 15.13). Internal standardization eliminated the % BIV, with pre-intervention LAZ ranging from-1.78 to 2.27, and post intervention LAZ: −2.27 to 2.04, falling within the WHO ranges for biologically plausible values (−6 SD &amp;lt; LAZ &amp;lt; 6 SD). Reliability of length measurements post-intervention was high as indicated by low relative TEM of 0.53%. Accuracy of 3D imaging was high (R = 0.99) comparing post-training vs. 3D imaging for length; however, examination of Bland Altman plots revealed that on average 3D scans overestimated length by 3.87 centimeters. Conclusions Training on standard anthropometry improved data quality. 3D imaging may be an accurate alternative to standard anthropometry, but adjustment of the technology is needed to avoid overestimation of length. Future research on the appropriate use of reference standards to define malnutrition in this severely ill population is needed. Funding Sources Bill &amp; Melinda Gates Foundation.

0294 Baseline Response Speed Predicts Locus Coeruleus Integrity Change After Sleep Deprivation

Abstract Introduction Locus coeruleus (LC) is the major source of norepinephrine (NE) in the brain, which plays a key role in maintaining arousal and alertness. Sleep loss significantly impairs arousal and alertness. However, it is unknown whether sleep loss disrupts LC integrity, which can be measured non-invasively by diffusion tensor imaging (DTI). In the current study, we used DTI to examine the effects of one night of acute total sleep deprivation (TSD) on fractional anisotropy (FA), an index reflecting fiber density, axonal diameter and myelination. Methods We analyzed DTI and psychomotor vigilance test (PVT) data from N=54 health adults (23 females, age range 21–50 years) from a well controlled in-laboratory sleep deprivation study. Participants were randomized to either a TSD condition (n=40) without sleep on night 2, or a control condition (n=14) with no sleep loss. Standard DTI scans were conducted on the morning of day 2 and day 3 between 0700h-1000h. The PVT reciprocal response time (RRT) was used to measure individual’s response speed at baseline without sleep loss. LC regions-of-interest (ROI) were defined by standard templates from Keren et al. (2009). Imaging data were analyzed using FSL toolbox. Results For the whole TSD group, no differences were found in the LC FA values before and after sleep deprivation (p &amp;gt; .2). However, when dividing the TSD group to a slow group and a fast group based on their baseline PVT response speed, significantly increased LC FA were found in the slow group (p = .007) but not in the fast group (p &amp;gt; .4). The PVT RRT negatively correlated with LC FA value changes after TSD (r = -.44, p = .004). No correlations were found between the PVT RRT and LC FA changes in the control group. Conclusion Our results showed that baseline vigilance response speed correlated with LC integrity change after sleep deprivation, with slower response exhibiting greater changes in LC integrity. These findings support the key role of LC-NE system in the regulation of alertness and arousal. Support Supported in part by NIH grants R01-HL102119, R01-MH107571, R21-AG051981. CTRC UL1RR024134, and P30-NS045839.

Nonmass Enhancement Breast Lesions: Diagnostic Performance of Kinetic Assessment on Ultrafast and Standard Dynamic Contrast-Enhanced MRI in Comparison With Morphologic Evaluation

OBJECTIVE. The purpose of this article was to evaluate the diagnostic performance of the kinetic parameters of ultrafast and standard dynamic contrast-enhanced MRI (DCE-MRI) compared with morphologic evaluation in differentiating benign from malignant nonmass enhancement (NME) breast lesions. MATERIALS AND METHODS. A total of 77 consecutive patients with 77 NMEs (23 benign and 54 malignant) underwent 3-T MRI, including one unenhanced and eight contrast-enhanced ultrafast DCE-MRI scans (7-second scans) and standard DCE-MRI scans. The two readers evaluated the lesions' likelihood of malignancy on a continuous scale from 0 to 100% as the morphologic score using standard DCE-MRI. The kinetic curves of ultrafast DCE-MRI were fitted using an empirical mathematical model, ΔS(t) = A × (1 - e-αt), where A is the upper limit of signal intensity, e is the Euler number, and alpha (s-1) is the rate of signal increase. The initial slope of the kinetic curve (A × α) and the initial AUC (AUC30, which is the integration of the kinetic curve from 0 to 30 seconds) were calculated. From standard DCE-MRI, initial enhancement rate and signal enhancement ratio (SER) were calculated. These parameters were compared between benign and malignant NMEs. RESULTS. The morphologic score of malignant NME was statistically significantly higher than that of benign NME (p < 0.0001). The upper limit of signal intensity, rate of signal increase, initial slope of the kinetic curve, and AUC30 of ultrafast DCE-MRI, initial enhancement rate, SER of standard DCE-MRI of malignant NMEs were statistically significantly higher than those of benign NMEs (p = 0.0011, 0.0045, < 0.0001, < 0.0001, 0.0017, and < 0.0001, respectively). AUC ROC analysis found no statistically significant difference between morphologic score, AUC30 of ultrafast DCE-MRI, or SER of standard DCE-MRI. CONCLUSION. The kinetic parameters of ultrafast and standard DCE-MRI were as effective as morphologic evaluation for differentiation between benign and malignant NMEs.

Effect of CBCT dose reduction on the mandibular canal visibility: ex vivo comparative study.

To compare the difference in mandibular canal (MC) visibility using three different cone beam computed tomography (CBCT) acquisition protocols: high resolution (HR), standard resolution (ST) and Quick scan+ (QS+). Twenty-five human dry mandibles were scanned by one CBCT machine; i-CAT FLX (Imaging Sciences International, Hatfield, PA, USA), using three different acquisition protocols: high-resolution (HR), standard (ST) and Quick scan+ (QS+). DICOM data were transferred to a third party software Ondemand 3D (Cybermed Co., Seoul, Korea). The fusion module was used to superimpose images derived from different acquisition protocols to standardize the areas to compare the MC visibility. Comparison was performed at nine selected cross sections extending from an area distal to the third molar posteriorly to the first premolar anteriorly. Two expert radiologists evaluated the degree of MC visibility using five-scale scoring system. There was a statistically significant difference between the three acquisition protocols (HR, ST, QS+) at all investigated areas regardless of dentition status (p value < 0.001-0.034) except at the MR1M area where there was no statistically significant difference (p value = 0.094). HR protocol showed the highest prevalence of fully and partially corticated MCat almost all investigated areas while QS+ protocol showed the highest prevalence of invisible MC and clear and unclear non-corticated MC at almost all investigated areas. QS+ protocol of i-CAT FLX CBCT machine is a recommended low-dose CBCT acquisition protocol for MC visibility at dentulous posterior mandibular regions while ST protocol is recommended at edentulous areas.

Long term outcome of early single stage surgery in multi-ligamentous injuries of knee

BackgroudMulti-ligamentous knee injuries have been a grey area due to unavailability of large scale control trials with a long term follow up. Several studies have documented good results with different protocols of management regarding time of treatment, repair versus reconstruction, choice of graft and sequence of repair. The author wishes to put forward long-term results of early (<6 weeks) single-stage surgery in multi ligamentous injuries. MethodsThe prospective trial included 29 patients diagnosed with three or more ligaments involved. Patients having fractures involving proximal tibia, distal femur, patella, patients with history of compound trauma to knee, osteochondral lesions, associated neuro-vascular injury & poly-trauma patients were excluded from the study. The patients also underwent AP, lateral & stress skiagrams in addition to a standard 3T MR scan for pre-operative planning and confirmation of diagnosis. The pre & post-operative outcomes were assessed using KSS & Lysholm score. The patients were followed up for two years with clinical examination and stress skiagrams. ResultsThe mean increase in knee scores was statistically significant at both 12 months and 24 months (p < 0.05) with mean ROM of 132.8° at final follow-up. Three patients required manipulation under anaesthesia. All patients could carry out their activities of daily living at mean period of 8.2 months. Osteoarthritis was most common complication at 2 years follow-up. ConclusionThe most important aspect of a single stage reconstruction lies in earlier restoration of function with a tremendous decrease in loss of medical expenses, improvement of quality of life and early & improved function in terms of both physical and psychological factors. Better restoration of kinematics from early rehabilitation is probably the factor responsible for the results. Osteoarthritis remains an important follow-up finding.

Can modifying shielding, field of view, and exposure settings make the effective dose of a cone-beam computed tomography comparable to traditional radiographs used for orthodontic diagnosis?

To analyze the effect of changes in exposure settings, field of view (FOV), and shielding on radiation to an adult and child phantom from cone-beam computed tomography (CBCT) imaging compared to panoramic and lateral cephalometric radiographs. The effective dose to an adult and child anthropomorphic phantom by the CS 9300 using various scan protocols was recorded. Absorbed radiation was measured with optically stimulated luminescence dosimeters and effective dose calculated using 2007 International Commission on Radiological Protection tissue weighting factors. Scan protocols included different FOVs, voxel sizes, and standard versus low-dose protocols. Radiation shielding was used when it did not interfere with FOV. Panoramic and lateral cephalometric radiographs were taken with the Orthophos SL. Even with shielding, smaller FOVs, and increased voxel sizes, the effective dose of standard CBCT scans was higher than panoramic and lateral cephalometric radiographs. A shielded limited FOV standard scan combined with a lateral cephalometric radiograph resulted in a lower dose (P < .001) than a full FOV standard scan. Low-dose shielded scans resulted in significant dose reductions to the adult (P < .05) and child (P < .001) phantoms compared to the respective panoramic and lateral cephalometric radiographs combined. Image quality analysis was not possible with radiation equivalent phantoms. Unlike standard CBCTs, shielded low-dose CBCT protocols in the CS 9300 have lower effective doses than conventional radiographs for adult and child phantoms. If high resolution and cranial base visualization are necessary, combining a shielded LFOV standard exposure with a cephalometric radiograph is recommended.

TO USE OR NOT USE PATIENT SHIELDING ON PREGNANT WOMEN UNDERGOING CT PULMONARY ANGIOGRAPHY: A PHANTOM STUDY.

Pregnancy increases the risk of pulmonary embolism. Computed tomography pulmonary angiography (CTPA) is used for diagnosis. CT generates ionising radiation, and thus, abdominal shielding may be used. This phantom study investigated the effects of patient shielding and scan length reduction on the fetal and maternal ionising radiation dose from CTPA. The absorbed dose to the fetus was measured using thermoluminescent dosemeters. Estimated effective doses to the pregnant patient were based on the dose-length products. Shielding increased both the effective dose to the patient by 47% and the mean absorbed dose to the fetus (0.10 vs. 0.12 mGy; p < 0.001) compared with unshielded standard CTPA, as it affected the automatic exposure control. Shielded short CTPA marginally lowered only the mean fetal absorbed dose (0.03 vs. 0.02 mGy; p = 0.018). Shortening the scan reduced the fetal absorbed dose most effectively by 70% (0.10 vs. 0.03 mGy; p = 0.006), compared with the standard unshielded scan. Shielding modestly reduces fetal radiation dose but may compromise automatic exposure control, possibly increasing the maternal and fetal radiation dose. Shortening the scan is beneficial, assuming anatomical coverage is secured.

Predictors of patient preference for either whole body magnetic resonance imaging (WB-MRI) or CT/ PET-CT for staging colorectal or lung cancer.

IntroductionWhole body magnetic resonance imaging (WB‐MRI) may be more efficient in staging cancers, but can be harder for patients to tolerate. We examined predictors of patient preference for WB‐MRI vs. CT/ PET‐CT for staging colorectal or lung cancer.MethodsPatients recruited prospectively to two multicentre trials comparing diagnostic accuracy of WB‐MRI with standard staging scans were sent two questionnaires: the first, administered at trial registration, captured demographics, educational level and comorbidities; the second, administered after staging completion, measured emotional distress (GHQ‐12), positive mood (PANAS), perceived scan burden, patients’ beliefs about WB‐MRI, and preference for either WB‐MRI or CT (colorectal trial), WB‐MRI or PET‐CT (lung trial). Preference for WB‐MRI or CT/ PET‐CT was analysed using logistic regression.ResultsBaseline and post‐staging questionnaires were completed by 97 and 107 patients, respectively. Overall, 56/107 (52%) preferred WB‐MRI over standard scans and were more likely to have no additional comorbidities, higher positive mood, greater awareness of potential benefits of WB‐MRI and lower levels of perceived WB‐MRI scan burden. In adjusted analyses, only awareness of potential WB‐MRI benefits remained a significant predictor (OR: 1.516, 95% CIs 1.006–2.284, P = 0.047). Knowledge that WB‐MRI does not use radiation predicted preference (adjusted OR: 3.018, 95% CIs 1.099–8.288, P = 0.032), although only 45/107 (42%) patients were aware of this attribute.ConclusionsA small majority of patients undergoing staging of colorectal or lung cancer prefer WB‐MRI to CT/ PET‐CT. Raising awareness of the potential benefits of WB‐MRI, notably lack of ionizing radiation, could influence preference.