Simulation and evaluation of increased imaging service capacity at the MRI department using reduced coil-setting times.

The wait times for patients from their appointments to receiving magnetic resonance imaging (MRI) are usually long. To reduce this wait time, the present study proposed that service time wastage could be reduced by adjusting MRI examination scheduling by prioritizing patients who require examinations involving the same type of coil. This approach can reduce patient wait times and thereby maximize MRI departments' service times. To simulate an MRI department's action workflow, 2,447 MRI examination logs containing the deidentified information of patients and radiation technologists from the MRI department of a medical center were used, and a hybrid simulation model that combined discrete-event and agent-based simulations was developed. The experiment was conducted in two stages. In the first stage, the service time was increased by adjusting the examination schedule and thereby reducing the number of coil changes. In the second stage, the maximum number of additional patients that could be examined daily was determined. The average number of coil changes per day for the four MRI scanners of the aforementioned medical center was reduced by approximately 27. Thus, the MRI department gained 97.17 min/d, which enabled them to examine three additional patients per month. Consequently, the net monthly income of the hospital increased from US$17,067 to US$30,196, and the patient wait times for MRI examinations requiring the use of flexible torso and head, shoulder, 8-inch head, and torso MRI coils were shortened by 6 d and 23 h, 2 d and 15 h, 2 d and 9 h, and 16 h, respectively. Adjusting MRI examination scheduling by prioritizing patients that require the use of the same coil could reduce the coil-setting time, increase the daily number of patients who are examined, increase the net income of the MRI department, and shorten patient wait times for MRI examinations. Minimizing the operating times of specific examinations to maximize the number of services provided per day does not require additional personnel or resources. The results of the experimental simulations can be used as a reference by radiology department managers designing scheduling rules for examination appointments.

BlueLight: An Open Source DICOM Viewer Using Low-Cost Computation Algorithm Implemented with JavaScript Using Advanced Medical Imaging Visualization.

Recently, WebGL has been widely used in numerous web-based medical image viewers to present advanced imaging visualization. However, in the scenario of medical imaging, there are many challenges of computation time and memory consumption that limit the use of advanced image renderings, such as volume rendering and multiplanar reformation/reconstruction, in low-cost mobile devices. In this study, we propose a client-side rendering low-cost computation algorithm for common two- and three-dimensional medical imaging visualization implemented by pure JavaScript. Particularly, we used the functions of cascading style sheet transform and combinate with Digital Imaging and Communications in Medicine (DICOM)-related imaging to replace the application programming interface with high computation to reduce the computation time and save memory consumption while launching medical imaging interpretation on web browsers. The results show the proposed algorithm significantly reduced the consumption of central and graphics processing units on various web browsers. The proposed algorithm was implemented in an open-source web-based DICOM viewer BlueLight; the results show that it has sufficient rendering performance to display 3D medical images with DICOM-compliant annotations and has the ability to connect to image archive via DICOMweb as well.Keywords: WebGL, DICOMweb, Multiplanar reconstruction, Volume rendering, DICOM, JavaScript, Zero-footprint.

Ensemble classification and segmentation for intracranial metastatic tumors on MRI images based on 2D U-nets.

The extraction of brain tumor tissues in 3D Brain Magnetic Resonance Imaging (MRI) plays an important role in diagnosis before the gamma knife radiosurgery (GKRS). In this article, the post-contrast T1 whole-brain MRI images had been collected by Taipei Veterans General Hospital (TVGH) and stored in DICOM format (dated from 1999 to 2018). The proposed method starts with the active contour model to get the region of interest (ROI) automatically and enhance the image contrast. The segmentation models are trained by MRI images with tumors to avoid imbalanced data problem under model construction. In order to achieve this objective, a two-step ensemble approach is used to establish such diagnosis, first, classify whether there is any tumor in the image, and second, segment the intracranial metastatic tumors by ensemble neural networks based on 2D U-Net architecture. The ensemble for classification and segmentation simultaneously also improves segmentation accuracy. The result of classification achieves a F1-measure of [Formula: see text], while the result of segmentation achieves an IoU of [Formula: see text] and a DICE score of [Formula: see text]. Significantly reduce the time for manual labeling from 30 min to 18 s per patient.

Can 3D artificial intelligence models outshine 2D ones in the detection of intracranial metastatic tumors on magnetic resonance images?

BACKGROUND: This study aimed to compare the prediction performance of two-dimensional (2D) and three-dimensional (3D) semantic segmentation models for intracranial metastatic tumors with a volume ≥ 0.3 mL. METHODS: We used postcontrast T1 whole-brain magnetic resonance (MR), which was collected from Taipei Veterans General Hospital (TVGH). Also, the study was approved by the institutional review board (IRB) of TVGH. The 2D image segmentation model does not fully use the spatial information between neighboring slices, whereas the 3D segmentation model does. We treated the U-Net as the basic model for 2D and 3D architectures. RESULTS: For the prediction of intracranial metastatic tumors, the area under the curve (AUC) of the 3D model was 87.6% and that of the 2D model was 81.5%. CONCLUSION: Building a semantic segmentation model based on 3D deep convolutional neural networks might be crucial to achieve a high detection rate in clinical applications for intracranial metastatic tumors.

Visiting in disguise: Analysis of inpatient companions in the time of COVID-19.

BACKGROUND: As outbreak of COVID-19 infection, on April 3, 2020, it is stipulated that the number of inpatient companions is limited to one in Taiwan. All companions are required to register their real personal data with 14 days of travel history, occupation, contact history, and cluster history. We would like to evaluate the impact of the new regulations to the accompanying and visiting culture in Taiwan, via analyzing the appearance and characteristics of inpatient companions in this period. METHODS: Using intelligent technology, we designed a novel system in managing the inpatient companions (InPatients Companions Management System [IPCMS]), and the IPCMS was used to collect data about characteristics of inpatients and companions between April 27 and May 3, 2020. The database is built using MySQL software. Microsoft Excel 2016 and SPSS version 20.0 statistical software were used for data analysis, including the basic data of the companions, differential analysis of companions' gender, person-days and cumulative time, differential analysis of accompaniment-patient relationship, and frequency of accompaniment and cumulative hours. RESULTS: During study period, daily inpatient admissions ranged from 2242 to 2514, the number of companions per day ranged from 2048 to 2293, and the number of companions for one inpatient is 1 to 9 per day, with an average of 1.20 to 1.26. The companions were mostly family members, and most of them were the inpatients' children (32.9%), and spouse (26.13%). More females than males were noted in all categories of companionship with statistical significance. CONCLUSION: The data obtained in this study could be an important basis for the transformation and reform of the companions culture in Taiwan's hospitals and will also provide a glimpse into the attitudes and culture of companions who have long been ignorant and neglected. The experience gained in our IPCMS could also serve as a reference for other hospitals in Taiwan and worldwide.

Hospital-Owned Apps in Taiwan: Nationwide Survey.

BACKGROUND: Over the last decade, the use of mobile phone apps in the health care industry has grown rapidly. Owing to the high penetration rate of Internet use in Taiwan, hospitals are eager to provide their own apps to improve the accessibility of medical care for patients. OBJECTIVE: The aims of this study were to provide an overview of the currently available hospital-owned apps in Taiwan and to conduct a cross-hospital comparison of app features. METHODS: In May 2017, the availability of apps from all 414 hospitals in Taiwan was surveyed from the hospital home pages and the Google Play app store. The features of the downloaded apps were then examined in detail and, for each app, the release date of the last update, download frequency, and rating score were obtained from Google Play. RESULTS: Among all the 414 hospitals in Taiwan, 150 (36.2%) owned Android apps that had been made available for public use, including 95% (18/19) of the academic medical centers, 77% (63/82) of the regional hospitals, and 22.0% (69/313) of the local community hospitals. Among the 13 different functionalities made available by the various hospital-owned apps, the most common were the doctor search (100%, 150/150), real-time queue monitoring (100%, 150/150), and online appointment scheduling (94.7%, 142/150) functionalities. The majority of apps (57.3%, 86/150) had a rating greater than 4 out of 5, 49.3% (74/150) had been updated at some point in 2017, and 36.0% (54/150) had been downloaded 10,000 to 50,000 times. CONCLUSIONS: More than one-third of the hospitals owned apps intended to increase patient access to health care. The most common app features might reflect the health care situation in Taiwan, where the overcrowded outpatient departments of hospitals operate in an open-access mode without any strict referral system. Further research should focus on the effectiveness and safety of these apps.

A rational approach to estimating the surgical demand elasticity needed to guide manpower reallocation during contagious outbreaks.

BACKGROUND: Emerging infectious diseases continue to pose serious threats to global public health. So far, however, few published study has addressed the need for manpower reallocation needed in hospitals when such a serious contagious outbreak occurs. AIM: To quantify the demand elasticity of the major surgery types in order to guide future manpower reallocation during contagious outbreaks. MATERIALS AND METHODS: Based on a nationwide research database in Taiwan, we extracted the monthly volumes of major surgery types for the period 1998-2003, which covered the SARS period, in order to carry out a time series analysis. The demand elasticity of each surgery type was then estimated by autoregressive integrated moving average (ARIMA) analysis. RESULTS: During the study period, the surgical volumes of most selected surgery types either increased or remained steady. We categorized these surgery types into low-, moderate- and high-elastic groups according to their demand elasticity. Appendectomy, 'open reduction of fracture with internal fixation' and 'free skin graft' were in the low demand elasticity group. Transurethral prostatectomy and extracorporeal shockwave lithotripsy (ESWL) were in the high demand elasticity group. The manpower of the departments carrying out the surgeries with low demand elasticity should be maintained during outbreaks. In contrast, departments in charge of surgeries mainly with high demand elasticity, like urology departments, may be in a position to have part of their staff reallocated. CONCLUSIONS: Taking advantage of the demand variation during the SARS period in 2003, we adopted the concept of demand elasticity and used a time series approach to figure out an effective index of demand elasticity for various types of surgery that could be used as a rational reference to carry out manpower reallocation during contagious outbreak situations.

Risk of post-vertebroplasty fracture in adjacent vertebral bodies appears correlated with the morphologic extent of bone cement.

BACKGROUND: New fractures in adjacent vertebral bodies were found after percutaneous vertebroplasty. We evaluated the correlation between extent of polymethylmethacrylate cement and occurrence of post-vertebroplasty fractures in patients with osteoporosis. METHODS: Totally 162 adjacent vertebral bodies with no fracture at the time of vertebroplasty and the distribution of cement in corresponding treated vertebral bodies of 98 patients were included for the evaluation. Length of follow-up after vertebroplasty was 734 ± 314 days (range, 366-1838 days). Based on proximity of bone cement to the adjacent vertebral body, cement extent was classified as disc level (the closest), endplate level, or trabecula level (the farthest). RESULTS: Forty-one adjacent vertebrae had post-vertebroplasty fracture occurring 2-1038 days after vertebroplasty. The percentages of adjacent vertebral bodies having post-vertebroplasty fracture about cement extent were: disc level, 44; endplate level, 29; and trabecula level, 7. CONCLUSION: Our study revealed that the risk of subsequent fracture in the adjacent vertebral bodies was correlated with the extent of bone cement after vertebroplasty. Preventive measures can be taken from this observation to reduce the percentage of post-vertebroplasty fracture in adjacent vertebral bodies.

Comparing the working time between Bar-Code Medication Administration system and traditional medication administration system: an observational study.

BACKGROUND: The medical institutions had paid attention to the medication error via Bar-Code Medication Administration system (BCMA) to improve the accuracy of the medication process for patient safety. Yet, the working time of drug delivery was under investigated. OBJECTIVES: Comparing the working time of oral drugs between Bar-Code Medication Administration system and traditional medication administration system. METHODS: Purposive sampling, observational and questionnaire study design was used. Participants were invited from a medical center in North Taiwan, 51 nurses from three neurosurgical wards who were using the BCMA system; 51 nurses from three neurological wards who were using traditional medication administration record (MAR). The working time of oral medication administration including order transcribing, verifying, drug giving, and renew in BCMA and traditional group were observed and recorded. RESULTS: (1) Working time for oral medication administration reduced from 36.49 to 18.42 s after BCMA implementation. (2) In the same period, working times for oral drug administration were 62.89 and 56.07 s before and after BCMA implementation in the traditional group. (3) Most nurses (66.7%) felt BCMA could save their oral drug administration time under 50%. (4) Frequent crash of the wireless network, which extended the oral drug administration time was the major threat in the process of BCMA implementation. (5) 93.5% nurses think that BCMA could enhance patient oral medication safety and promote quality of oral medication. CONCLUSIONS: The results demonstrated that implementation of BCMA for oral medication could reduce half of the time for oral medication delivery. Nurses coordinated the hardware and software by accommodating the new facilities and operating BCMA system. The stability of wireless Internet was the main threat. However, 93.5% nurses think that BCMA could enhance patient oral medication safety in spite of making more effort in learning new technology.

Torticollis due to atlantoaxial rotatory fixation.

Torticollis due to atlantoaxial rotatory fixation (AARF) is rare. Most cases are idiopathic or occur after infection or minor trauma. AARF can cause neurologic deficits, and patients often present with torticollis that fails to resolve. AARF should be excluded before idiopathic spasmodic torticollis is diagnosed. Computed tomography helps in confirming AARF, and early diagnosis can improve outcomes, although treatment is debatable. We present three children and one adult with AARF and review the literature.

Are Non-contrast MR Images enough for Detection of Fracture Levels Prior to Percutaneous Vertebroplasty in Patients with Osteoporosis?

SUMMARY: We evaluated the detectability of painful vertebral compression fractures (VCFs) on different MRI protocols in 40 osteoporotic patients with thoraco-lumbar osteoporotic vertebral fractures. Five hundred and ten thoracic and lumbar vertebrae in 40 patients were evaluated. All patients underwent percutaneous vertebroplasty. Vertebral fractures were found in 126 (24.7%) of 510 vertebrae. Healed vertebral fractures were found in 33 (26.2%) of 126 vertebral fractures. Painful osteoporotic VCFs was found in 93 (73.8%) of 126 fractures. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of contrast-enhanced MR images, and the non-contrasted combined protocol (including T1-weighted, T2-weighted and STIR images) for the detection of painful osteoporotic VCFs were all more than 90%. Therefore, the non-contrasted combined protocol can be used for detection of painful osteoporotic VCFs prior to percutaneous vertebroplasty, unless there are conditions where contrast-enhanced MR is needed to rule out other causes of VCFs.

The current role of 1.5T non-contrast 3D time-of-flight magnetic resonance angiography to detect intracranial steno-occlusive disease.

BACKGROUND/PURPOSE: This study was performed to evaluate the role of non-contrast 3D time-of-flight (TOF) magnetic resonance angiography (MRA) to detect and quantify intracranial steno-occlusive disease. METHODS: Between April 2004 and January 2006, 45 patients with both 1.5T TOF MRA and digital subtraction angiography (DSA) performed within a 30-day interval were included. We evaluated the following intracranial arterial segments: petrous internal carotid artery (ICA), cavernous ICA, supraclinoid ICA, M1 of middle cerebral artery, A1 of anterior cerebral artery, P1 of posterior cerebral artery, basilar artery, and distal vertebral artery. In total, 675 arterial segments were evaluated and categorized as negative, moderate-1 (3049% stenosis), moderate-2 (5069%), severe (7099% stenosis, including gap sign on MRA), and occlusion. RESULTS: The sensitivity and specificity of TOF MRA for > 29% stenosis and > 49% stenosis were 94%, 96% and 95%, 96%, respectively; while sensitivity and specificity for occlusion lesions were both 100%. However, 44 segments (37% of diseased segments) were overestimated by MRA, including 20 false-positive stenoses (which occurred in 10 [22%] patients) and 24 overestimated stenosis degree. The gap sign as severe stenosis only showed about 21% sensitivity and 41% specificity. Seven lesions were underestimated by MRA: three arterial segments were out of the field of MRA examination, and four were moderate-1stenosis on DSA. CONCLUSION: TOF MRA has high sensitivity and specificity in detecting all categories of stenosis degree and occlusion. However, it tends to overestimate lesions. Therefore, MRA can be considered as a screening study. Confirmation with other studies is recommended in doubtful cases.

The Relationship between Carotid Artery Diameter and Percentage of Stenosis.

In order to understand percentage of stenosis from the residual lumen of the carotid artery, we explored the relationship between the residual diameter at the carotid stenosis, its stenosis percentage and the size of the internal carotid artery. Diameters of 103 carotid arteries of Taiwan residents were retrospectively measured from digital subtraction angiograms. Severe cases of near occlusion with the angiographic string sign, and cases with tandem lesions or intracranial occlusion were excluded. Of the total 103 carotid arteries, 22 (21%) had one or both of the following signs of reduced distal arterial caliber: (1) obvious narrowing of the distal carotid artery; (2) the caliber of the cervical internal carotid artery was smaller than the caliber of the corresponding external carotid artery. That the diameter of the distal carotid artery was smaller when the stenosis was greater at the site of minimal lumen was true in the group of patients with signs of reduced distal caliber and in the group of patients without such signs. Therefore, reduced distal caliber may be present in patients without such signs. After excluding cases with at least one of the above signs of reduced distal arterial caliber, the relation between percentage of stenosis (y) and the absolute value of the diameter at the stenosis (x) can be represented by the formula: y = 96.83-18.27 x. From our data, a diameter of 2 mm is about 60% stenosis and 1.5 mm is 70% stenosis. According to this formula, we can estimate percentage of carotid stenosis using residual diameter at the site of minimal lumen obtained from other imaging modalities, such as carotid Doppler, CT angiogram or MR angiogram.

Variable pump flow-based Doppler ultrasound method: a novel approach to the measurement of access flow in hemodialysis patients.

Decreasing vascular access flow (Qa) is an important predictor of future access thrombosis and malfunction for hemodialysis (HD) patients. Among all of the methods for determining Qa, the variable pump flow (VPF) Doppler method measures Qa according to the change in Doppler signal between the arterial and the venous needles under different pump flow. After this technique was combined with spectral analysis of Duplex Doppler imaging, the variable pump flow-based Doppler ultrasound method (VPFDUM) for Qa measurement was developed. This study compared the reproducibility and correlation of Qa measurements for three different methods-VPFDUM, ultrasound dilution method (UDM), and conventional Doppler ultrasound method (CDUM)-in 55 HD patients. The mean value of Qa by VPFDUM (870.8 +/- 412.0 ml/min) was close to that by UDM (868.6 +/- 417.9 ml/min) but higher than that by CDUM (either of the above values versus 685.1 +/- 303.6 ml/min; P < 0.005). The mean values of coefficient of variation were similar by VPFDUM (1.6%) and UDM (1.4%) but lower than that by CDUM (either of the above values versus 6.8%; P < 0.01). The correlation coefficient and intraclass correlation coefficient of the repeated Qa measurements by VPFDUM (0.985 and 0.993; P < 0.001) were also similar to those by UDM (0.992 and 0.995; P < 0.001) but slightly higher than those by CDUM (0.917 and 0.948; P < 0.005). Either the reproducibility of VPFDUM (r=0.98, P < 0.0001) or the correlation between VPFDUM and UDM (r=0.99, P < 0.0001) in Qa measurements is good. The unassisted patency of vascular access at 6 mo was significantly poorer in patients with Qa <500 ml/min than those with Qa >500 ml/min (13.6% versus 92.2%; P < 0.0001). In conclusion, VPFDUM is a noninvasive, accurate, and reliable procedure for Qa measurement and prediction of the prognosis of vascular access in HD patients.

Comparison of shoulder ultrasound and MR imaging in diagnosing full-thickness rotator cuff tears.

Ultrasound (US) and magnetic resonance imaging (MRI) of 422 cases were evaluated to compare the feasibility in diagnosing full-thickness rotator cuff tears (FTRCTs). On the basis of different US performers, they were divided into two groups: Group 1 performed by a 5-year experience technician and Group 2 performed by a 10-year experience radiologist. Sensitivity, negative predictive value (NPV), accuracy of US, and correlation between the two modalities were better in Group 2. When an expert is available, US can be used for diagnosing FTRCTs; otherwise, MRI should be performed.