bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computed Tomography Cholangiography Using the Magnetic Resonance Contrast Agent Gadoxetate Disodium
Authors: Dilger Samantha K.N. , Nelson Noelle , Venkatesh Sudhakar K. , Ehman Eric C. , Fidler Jeff L. , Fletcher Joel G. , McCollough Cynthia H. , Yu Lifeng 
Published: July 2019

Objective
The purpose of this work is to determine whether low doses of gadoxetate disodium (Eovist; Bayer Healthcare LLC, Whippany, NJ), a gadolinium-based contrast agent used for magnetic resonance liver imaging, can be visualized for computed tomography (CT) cholangiography using a phantom setup.

Materials and Methods
Vials containing 4 concentrations of gadoxetate disodium (1.9, 3.4, 4.8, and 9.6 mg Gd/mL) were placed in a 35 × 26-cm2 water phantom and imaged on 2 CT scanners: Siemens Somatom Flash and Force (Siemens Healthcare, Erlangen, Germany). These concentrations correspond to the estimated concentration in the bile duct for a 40-, 70-, or 100-kg patient, and twice the concentration of a 100-kg patient, respectively. Single-energy (SE) scans were acquired at 70, 80, 90, 100, 120, and 140 kVp, and dual-energy scans were acquired at 90/150Sn (Force) and 100/150 (Flash) for 2 dose levels (CTDIvol 13 and 23 mGy). Virtual monoenergetic images at 50 keV were created (Mono+; Siemens Healthcare, Erlangen, Germany). The mean intensity and standard deviation for each concentration of gadoxetate disodium and the water background were extracted from each image set and used to compute the contrast and contrast-to-noise ratio (CNR). To determine whether the signal provided by gadoxetate disodium was clinically sufficient, the measures were compared with those acquired from 12 clinical CT cholangiography examinations performed with iodine-containing iodipamide meglumine.

Results
From the retrospective clinical cohort, mean contrast (± standard deviation) of 239 ± 107 HU and CNR of 12.8 ± 4.2 were found in the bile duct relative to the liver. Comparing these metrics to the gadoxetate disodium samples, the highest concentration (9.6 mg Gd/mL) surpassed these thresholds at all energy levels. The 4.8 mg Gd/mL had sufficient CNR in the Force, but not in the Flash. The 3.4 mg Gd/mL had clinically relevant CNR at low kV of SE (<100 kVp) and 50 keV of dual energy in the Force but was insufficient in the Flash. Images acquired by the Force had a lower noise level and greater CNR compared with the Flash. Similar trends were seen at both dose levels.

Conclusions
Gadoxetate disodium shows promise as a viable contrast agent for CT cholangiography, with CNR similar to those seen clinically with an iodine-based contrast agent. Dual-energy CT or low kV SE-CT is helpful to enhance the signal.
Can Virtual Contrast Enhancement in Brain MRI Replace Gadolinium?
Authors: Kleesiek Jens , Morshuis Jan Nikolas , Isensee Fabian , Deike-Hofmann Katerina , Paech Daniel , Kickingereder Philipp , Köthe Ullrich , Rother Carsten , Forsting Michael , Wick Wolfgang , Bendszus Martin , Schlemmer Heinz-Peter , Radbruch Alexander 
Published: July 2019

Objectives
Gadolinium-based contrast agents (GBCAs) have become an integral part in daily clinical decision making in the last 3 decades. However, there is a broad consensus that GBCAs should be exclusively used if no contrast-free magnetic resonance imaging (MRI) technique is available to reduce the amount of applied GBCAs in patients. In the current study, we investigate the possibility of predicting contrast enhancement from noncontrast multiparametric brain MRI scans using a deep-learning (DL) architecture.

Materials and Methods
A Bayesian DL architecture for the prediction of virtual contrast enhancement was developed using 10-channel multiparametric MRI data acquired before GBCA application. The model was quantitatively and qualitatively evaluated on 116 data sets from glioma patients and healthy subjects by comparing the virtual contrast enhancement maps to the ground truth contrast-enhanced T1-weighted imaging. Subjects were split in 3 different groups: enhancing tumors (n = 47), nonenhancing tumors (n = 39), and patients without pathologic changes (n = 30). The tumor regions were segmented for a detailed analysis of subregions. The influence of the different MRI sequences was determined.

Results
Quantitative results of the virtual contrast enhancement yielded a sensitivity of 91.8% and a specificity of 91.2%. T2-weighted imaging, followed by diffusion-weighted imaging, was the most influential sequence for the prediction of virtual contrast enhancement. Analysis of the whole brain showed a mean area under the curve of 0.969 ± 0.019, a peak signal-to-noise ratio of 22.967 ± 1.162 dB, and a structural similarity index of 0.872 ± 0.031. Enhancing and nonenhancing tumor subregions performed worse (except for the peak signal-to-noise ratio of the nonenhancing tumors). The qualitative evaluation by 2 raters using a 4-point Likert scale showed good to excellent (3–4) results for 91.5% of the enhancing and 92.3% of the nonenhancing gliomas. However, despite the good scores and ratings, there were visual deviations between the virtual contrast maps and the ground truth, including a more blurry, less nodular-like ring enhancement, few low-contrast false-positive enhancements of nonenhancing gliomas, and a tendency to omit smaller vessels. These “features” were also exploited by 2 trained radiologists when performing a Turing test, allowing them to discriminate between real and virtual contrast-enhanced images in 80% and 90% of the cases, respectively.

Conclusions
The introduced model for virtual gadolinium enhancement demonstrates a very good quantitative and qualitative performance. Future systematic studies in larger patient collectives with varying neurological disorders need to evaluate if the introduced virtual contrast enhancement might reduce GBCA exposure in clinical practice.
Real-Time Magnetic Resonance Imaging
Authors: Frahm Jens , Voit Dirk , Uecker Martin 
Published: July 2019

Objective
The aim of this study is to evaluate a real-time magnetic resonance imaging (MRI) method that not only promises high spatiotemporal resolution but also practical robustness in a wide range of scientific and clinical applications.

Materials and Methods
The proposed method relies on highly undersampled gradient-echo sequences with radial encoding schemes. The serial image reconstruction process solves the true mathematical task that emerges as a nonlinear inverse problem with the complex image and all coil sensitivity maps as unknowns. Extensions to model-based reconstructions for quantitative parametric mapping further increase the number of unknowns, for example, by adding parameters for phase-contrast flow or T1 relaxation. In all cases, an iterative numerical solution that minimizes a respective cost function is achieved with use of the iteratively regularized Gauss-Newton method. Convergence is supported by regularization, for example, to the preceding frame, whereas temporal fidelity is ensured by downsizing the regularization strength in comparison to the data consistency term in each iterative step. Practical implementations of highly parallelized algorithms are realized on a computer with multiple graphical processing units. It is “invisibly” integrated into a commercial 3-T MRI system to allow for conventional usage and to provide online reconstruction, display, and storage of regular DICOM image series.

Results
Depending on the application, the proposed method offers serial imaging, that is, the recording of MRI movies, with variable spatial resolution and up to 100 frames per second (fps)—corresponding to 10 milliseconds image acquisition times. For example, movements of the temporomandibular joint during opening and closing of the mouth are visualized with use of simultaneous dual-slice movies of both joints at 2 × 10 fps (50 milliseconds per frame). Cardiac function may be studied at 30 to 50 fps (33.3 to 20 milliseconds), whereas articulation processes typically require 50 fps (20 milliseconds) or orthogonal dual-slice acquisitions at 2 × 25 fps (20 milliseconds). Methodological extensions to model-based reconstructions achieve improved quantitative mapping of flow velocities and T1 relaxation times in a variety of clinical scenarios.

Conclusions
Real-time gradient-echo MRI with extreme radial undersampling and nonlinear inverse reconstruction allows for direct monitoring of arbitrary physiological processes and body functions. In many cases, pertinent applications offer hitherto impossible clinical studies (eg, of high-resolution swallowing dynamics) or bear the potential to replace existing MRI procedures (eg, electrocardiogram-gated cardiac examinations). As a consequence, many novel opportunities will require a change of paradigm in MRI-based radiology. At this stage, extended clinical trials are needed.
Evaluation of Skeletal Muscle Microcirculation and Reserve Function of the Type 2 Diabetes with Contrast-Enhanced Ultrasonography
Authors: Xu Zhen-Hong , Chen Jiao-Hong , Huang Feng-Bin , Lv Guo-Rong 
Published: July 2019

Objective
This study aimed to discuss clinical application value of contrast-enhanced ultrasonography on lesion skeletal muscle microcirculation and arterial perfusion reserve in type 2 diabetes mellitus and complicated microvessels.

Methods
Patients in the control group, type 2 diabetes mellitus (DM) group, diabetic microangiopathy (DM + MC) group underwent contrast-enhanced ultrasonography before and after temporary arterial occlusion to observe blood perfusion of gastrocnemius muscle; draw the time-intensity curve of arteriole, muscular tissue, and venule, and obtain perfusion parameters such as contrast agent arrival time and contrast agent transit time. Blood glucose, insulin, insulin resistance index, and relevant blood rheology parameters were measured.

Results
Contrast agent transit time of the DM + MC group before arterial occlusion was significantly longer than that of the DM group and control group (P < 0.05). Contrast agent transit time of the DM + MC group after temporary arterial occlusion was significantly longer than that of the DM group and control group (P < 0.05). Contrast agent transit time of △artery-muscle, △artery-vein, and △muscle-vein of the DM group and control group and △artery-muscle of the DM + MC group after arterial occlusion was significantly shortened, when compared with that before arterial occlusion (P < 0.05). For △muscle-vein and △artery-vein contrast agent transit time in the DM + MC group, the difference was not statistically significant. By comparing blood glucose, insulin, insulin resistance index, and relevant blood rheology parameters among the DM + MC group, DM group, and control group, the difference was statistically significant, and there was a good correlation.

Conclusion
Contrast-enhanced ultrasonography can be used to evaluate skeletal muscle microcirculation disturbance and arterial reserve function of patients who had type 2 diabetic microangiopathy.
Assessment of Somatosensory Reorganization by Functional Magnetic Resonance Imaging After Hand Replantation
Authors: Guillier David , Moris Vivien , Daubail Benoit , Rizzi Philippe , Tchurukdichian Alain , Baudoin Nathalie , Bejot Yannick , Zwetyenga Narcisse , Jacquin-Piques Agnes 
Published: July 2019

Introduction
Amputation of the hand is a rare and extremely intense trauma. Replanting and allografting after this type of injury require a major reorganization of the brain. Brain plasticity, though better known in the context of disorders of the central nervous system, is just as indispensable when the extremities are damaged.

Materials and Methods
A 17-year-old patient underwent replantation of the nondominant hand after transmetaphyseal amputation after traumatic injury. After 18 days in hospital and subsequent treatment in a physical rehabilitation center, the patient attended clinical and radiology follow-up sessions over the next 2 years.

Results
The management of this patient led to an excellent functional outcome in conjunction with successful social and professional reintegration. Electromyography at 18 months confirmed nerve regrowth. Functional magnetic resonance imaging was done at 2 years to evaluate cerebral plasticity. Motor function, largely dependent on the primary motor area, is aided by the addition of secondary and accessory motor areas for both simple and complex movements. A change in sensory information is stimulation in its own right hemisphere and increases solicitation of the contralateral precentral and postcentral gyrus.

Conclusions
There seems to be a real reversible dynamic plasticity under the balance of inhibitory and excitatory influences exerted on the cortical neurons. Any disruption of this balance requires the brain to adapt to the new circumstances to reestablish the hand as a functioning part of the body.
Cranial Erosion Associated With Non-Midline Dermoid Cysts in the Pediatric Population
Authors: Van Kouwenberg Emily , Kanth Aditi M. , Mountziaris Paschalia , Adetayo Oluwaseun A. 
Published: July 2019

Background:
While the risk for intracranial extension of midline nasoglabellar dermoid cysts is well-described, the risk in non-midline dermoid cysts and role of preoperative imaging in these lesions is less understood. This study aims to address this gap and provide preoperative recommendations.

Materials and Methods:
A retrospective review was performed evaluating patients who underwent excision of craniofacial dermoid cysts by a single surgeon. Findings on preoperative physical examination and imaging modalities were compared to intraoperative findings to assess effectiveness of each in predicting bony erosion. A treatment algorithm is proposed.

Results:
Twenty-eight patients were included and 50% had intraoperatively confirmed bony erosion. Bony erosion was identified in 100% of lesions immobile on examination, compared to 30% of mobile lesions (P = 0.001). Bony erosion was identified in 40.9% of lateral brow cysts compared to 83.3% of lesions located elsewhere (P = 0.03), in 60% of patients with periorbital sequelae compared to 47.8% without periorbital sequelae, and in 66.7% of patients with reported change in cyst size with Valsalva compared to 48.0% without change with Valsalva. Sensitivities for preoperative identification of bony erosion were as follows: physical examination 57.1%, US 11.1%, MRI 66.7%, and CT 100%.

Conclusions:
A management algorithm for non-midline dermoid cysts is presented. CT or MRI is recommended for lesions that are immobile, in atypical locations, or have associated periorbital sequelae or change with Valsalva. The authors feel there is no role for ultrasound and don’t recommend routine imaging in patients with non-midline dermoid cysts without features suggestive of bony erosion.
Autologous Fat Grafting for the Treatment of Mild to Moderate Velopharyngeal Insufficiency
Authors: Adams Saleigh , Xoagus Elizabeth A. , Lazarus Dirk , Lentin Roslyn , Hudson Donald A. 
Published: July 2019

Background:
To assess speech results following the treatment of mild to moderate velopharyngeal insufficiency (VPI) post cleft palate surgery with autologous fat grafting to the velopharynx.

Methods:
A retrospective study was conducted on 9 consecutive patients who underwent velopharyngeal fat grafting for the treatment of VPI at the Red Cross War Memorial Children's hospital from 2010 to 2014. All the patients previously had primary palatoplasty performed and subsequently developed VPI. Patients were assessed pre- and postoperatively by an experienced speech and language therapist looking at perceptual speech and by 2 senior cleft surgeons interpreting lateral view videofluoroscopies.

Results:
Eleven fat grafting procedures were performed on 9 patients and an average of 5.64 mL (range 1–7 mL) of autologous fat was transferred to the velopharynx. The average age at the time of operation was 6.5 years (range 3–14 years) with a follow-up period of 18 months (range 7–34 months). Most of the patients (7 out of 9) showed improved speech after fat grafting. One of the 7 patients had multiple procedures. The 2 who did not show speech improvement only had a single procedure. There were no complications related to the fat grafting procedure.

Conclusion:
This small study suggests that fat grafting either as a single procedure or as multiple procedures is an effective, safe, minimally invasive surgical alternative, and/or adjunct for the treatment of mild to moderate VPI in patients following cleft palate surgery and to the knowledge, is the first reported study from Africa.
Perioperative Outcomes Following Pediatric Cranial Vault Remodeling: Are Improvements Possible?
Authors: Morrow Brad T. , Ditthakasem Kanlaya , Herbert Morley , Fearon Jeffrey A. 
Published: July 2019

Purpose:
The Pediatric Craniofacial Collaborative Group recently reported pooled perioperative data from 31 North American centers performing open cranial vault remodeling procedures. The authors sought to determine if outcomes were different at a single higher-volume center and if identified, ascertain reasons for any differences and propose strategies for improvement.

Methods:
A retrospective review was performed of all open pediatric cranial vault procedures performed at our center during the identical 3.25-year period reported by the Collaborative group, including demographic, perioperative management and outcome data, to permit multiple comparative analyses.

Results:
The 310 procedures were performed by our center during this time period, compared to 1223 by the combined 31 institutions (median: 29.5 cases/center; interquartile range: 12–54.5). Multiple outcome differences were found: our higher-volume center had a significantly lower overall red blood cell transfusion rate (≤2 years: 7.5 percent vs 91 percent, P <0.001), those requiring transfusions were transfused considerably smaller volumes (≤2 years: 3.8mL/kg vs 45.3 mL/kg, P <0.001), and exposure to ≥3 blood donors was significantly less (none vs 20 percent, P <0.001). There were no mortalities in either group, but almost all matched adverse events were less common at our center. Both the intensive care unit and hospital lengths of stay were significantly shorter at our center (1 vs 2 days, 2 vs 4 days, both P <0.001).

Conclusions:
Perioperative outcomes following pediatric craniosynostosis corrections performed at a single higher-volume center compare favorably to median national data. Multiple potential strategies to reduce blood utilization, minimize perioperative complications, and shorten hospitalizations are proposed.
A Promising New Technique for Correcting a Deviated Nose: Partial Disarticulation of Keystone Area
Authors: Cabbarzade Cavid 
Published: July 2019

Abstract
Correction of the septum is essential for the correction of deviated nose. If no intervention is made to the septum that does not start from midline at the keystone area, either the crookedness will persist or thicker spreader grafts will need to be placed at the opposite side of the crookedness or further camouflaging will be required. The latter may cause dorsum to get wider. In the present study, partial disarticulation of keystone (PDK) method is presented for the correction of septum that does not start from the midline at the keystone area. This retrospective study included 18 patients in whom PDK method was employed to correct nasal deformity. The keystone area was repositioned by disarticulating the cartilage from the bone on the anterior part of the junction of the ethmoid bone with the septal cartilage. The patients were followed up for the duration of 12 to 33 (mean: 22.5) months. No patients developed a serious complication or required revision surgery. The PDK method can be applied to patients if dorsal septum does not start from the midline at the keystone area. This is a minimally invasive, time-saving method that has a short learning curve and decreases the possibility of further widening of dorsum.
Cone-Beam Computed Tomography Study of Mandibular Condylar Morphology
Authors: Yalcin Eda Didem , Ararat Emine 
Published: July 2019

Objective:
The purpose of this study was to evaluate the morphology of mandibular condyle using cone-beam computed tomography (CBCT) on coronal sections in a South-Eastern Anatolian population.

Methods:
A total of 1820 joints in 910 subjects with age range of 18 to 86 years were examined retrospectively on CBCT images. The mandibular condylar morphology was examined in right and left sides on coronal sections and classified as convex, round, flat, and angled. In addition, condyle morphology was assessed according to age, gender, edentulism, Angle's classification.

Results:
The study sample contained CBCT scans of 910 patients (50.3% female, 49.7% male) with a mean age of 42.31 ± 15.74. Condylar morphologies were analyzed as convex in 40.5%, angled in 34.3%, flat in 15.5%, round in 9.6% of the cases. Condyle shape was found statistically related to group age, gender, edentulism (P <0.05).

Conclusion:
The findings suggest that mandibular condyle shape is associated with age, gender, and edentulism. CBCT may be considered as an appropriate imaging method for detection of condyle alterations of temporomandibular joints and it could provide early diagnosis of temporomandibular joint disorder.
Incidence of Preventable Nonfatal Craniofacial Injuries and Implications for Facial Transplantation
Authors: Kantar Rami S. , Alfonso Allyson R. , Ramly Elie P. , Diaz-Siso J. Rodrigo , Jacoby Adam , Sosin Michael , Ceradini Daniel J. , Rodriguez Eduardo D. 
Published: July 2019

Introduction:
The number of patients who may benefit from evaluation for face transplantation in the United States (US) remains largely unknown. The goal of our study was to better delineate the pool of patients who might benefit from face transplant evaluation based on the characteristics and mechanisms of injury of previously reported face transplant recipients.

Methods:
The authors utilized data from the National Electronic Injury Surveillance System-All Injury Program in this study. The US Census Bureau data were used for population estimates. Inclusion and exclusion criteria were determined based on the characteristics of face transplant recipients to date, and the mechanisms of injury they sustained ultimately necessitating face transplantation. Statistical significance was reached if P <0.05.

Results:
The estimated annual incidence of preventable craniofacial injuries from firearms (44,266–58,299; 31.7% increase), burns (5712–19,433; 240.2% increase), and animal attacks (5355–14,666; 173.9% increase) increased from 2005 to 2014, whereas the estimated annual incidence of craniofacial injuries from machinery (3927–2933; 25.3% decrease) decreased between 2005 and 2014. The authors estimate the annual incidence rate to fall between 32.1 per 100,000 and 58.1 per 100,000 among individuals aged 20 to 64 in the US.

Conclusion:
In this study, the authors estimate the annual incidence rate of individuals aged 20 to 64 in the US who may benefit from face transplant evaluation and believe that this quantification has the potential to initiate actionable discussions regarding geographical and financial factors affecting access to care in this patient population.