Mobile Computed Tomography Scanner Research Articles

Initial experience with astate-of-the-art mobile head CT scanner for use in neurointensive care units.

Mobile head computed tomography (CT) scanners can reduce transport-related complications in neurointensive care unit (NICU) patients and decrease the burden on NICU staff; however, the initial investment cost and reduced image quality of early mobile scanners have prevented their widespread clinical use. Here, we report our initial experience with anovel 32-row mobile CT scanner for use in NICUs. Over a2-year period, 107 patients received amobile head CT scan. The technical characteristics of the scanner and the organizational procedures are described in detail. Patient characteristics were retrospectively collected and image quality was subjectively evaluated on aLikert scale ranging from 0 to 5 and compared with astationary CT scanner. Mobile head CT was used for follow-up of intracranial hemorrhage in 51%, routine postoperative imaging in 28%, evaluation of neurological deterioration in 14%, bedside monitoring after external ventricular drain placement in 4%, and follow-up of ischemic stroke in 3% of cases. Diagnostic imaging quality was achieved in all cases, eliminating the need for stationary CT scanning. The overall image quality of mobile CT (median 4points) was inferior to that of conventional stationary CT (median 5points, p < 0.01), but was rated with 4 or 5points in the majority of cases. State-of-the-art mobile CT was found to be easy to use and maneuver and has the potential to expedite the diagnosis of NICU patients and reduce staff workload. Image quality was adequate for common NICU issues.

Quality Assessment of Mobile Cone-beam Computerized Tomography Scanner Made in Thailand: A Phantom Study

Background: In 2011, the National Science and Technology Development Agency had successfully developed the first local-made mobile conebeam computed tomography (CBCT) scanner, called MobiiScan. Before a computed tomography (CT) scanner can be used in clinical practice, it must pass a quality assurance process. Objective: To assess the performance of MobiiScan before it can be further evaluated in human subjects. Materials and Methods: Images from scanning of an imaging phantom by MobiiScan were compared to a commercial 64-slice (GE Discovery CT750 HD) and a mobile (Neurologica CereTom) CT scanner, which were used as controls. Spatial resolution, uniformity, noise, accuracy of CT number, and geometric accuracy were examined by three investigators. Results: According to the bone scanning protocol, spatial resolution of the images produced by MobiiScan was comparable to the mobile scanner, but it was less than the 64-slice scanner. In addition, the signal uniformity of MobiiScan was poorer compared to the controls. MobiiScan produced more noise than the mobile and the 64-slice scanners at the 120-kVp mode, but less noise than the 64-slice scanner at the 80-kVp mode. Using the brain protocol, the spatial resolution from the MobiiScan was higher than the mobile scanner, but comparable to the 64-slice scanner. Although the signal uniformity of the MobiiScan was superior compared to the controls, the noise production was more than the controls. At all settings, the MobiiScan gave underrated distances and inaccurate CT numbers. However, it delivered very low radiation doses. Conclusion: MobiiScan had a good spatial resolution and delivered low radiation dose, which suggested that it could be used for bone examination as intended by the creator. However, its noise production and inaccurate CT numbers suggest that MobiiScan should not be used to diagnose soft tissue problems. It is recommended that the hardware and software should be adjusted to provide a better signal uniformity, lower noise level, accurate CT number, and geometric accuracy. Keywords: X-ray computed tomography; Cone-beam computed tomography; Craniofacial abnormalities; Radiologic phantom; MobiiScan

Cost Effectiveness of Mobile versus Fixed Computed Tomography and Magnetic Resonance Imaging: A Systematic Review

Mobile technologies are widely used in healthcare. The purpose of this study was to compare the effectiveness and cost-effectiveness of fixed computed tomography (CT) and magnetic resonance imaging (MRI) with the mobile ones. In this systematic review, PubMed, Cochrane Library, Scopus and CRD database were searched from 1995 to 2015. The data on safety and effectiveness of technologies were extracted from included studies. Because the review showed no significant differences in the performance of mobile CT and MRI compared to the fixed ones, then a cost minimization approach was used to explore the cost-effectiveness of three scenarios. Twenty two articles were included in the review that showed no statistically significant differences in the performance of mobile MRI and CT scan compared to the fixed ones. The cost minimization approach showed that the third scenario based on purchasing a common mobile MRI and CT scan; and using it by two or more hospitals that are in rational distance from each other is associated with the lowest costs, so it is the most cost-effectiveness strategy. The performance of Mobile CT and mobile MRI is comparable to the fixed ones; and using a combined mobile CT and MRI by two or three hospitals is the most cost-effective approach.

Marking method for peripheral non-palpable pulmonary nodules using a mobile computed tomography scanner with a navigation system.

Intraoperative localization is essential for video-assisted thoracoscopic surgery of non-palpable pulmonary nodules. Although a computed tomography (CT) guided hook-wire localization is widely used, it might be accompanied by a rare but fatal complication such as an air embolism. We applied a mobile CT scanner with a navigation system to resolve this problem. The three-dimensional images obtained by the mobile CT scanner were transferred to the navigation system, which allowed for virtual fluoroscopy to scan the nearest skin site from the target lesion using a navigation probe. The lung surface was stamped by a dyed gauze ball anchored just beneath the skin marking and a needle was placed at this point as a landmark. With this method, we could verify the positional relationship between the needle and target lesion by the additional CT scan without any procedure-related morbidity.

A Comparison of Intra-Observer and Inter-Observer Reliability of Plain Radiographs, Standard Computed Tomography Scans and Mobile Computed Tomography Scans in the Assessment of Distal Radius Fractures: A Cadaveric Study

Objective: Diagnosis of a distal end radius fracture relies on various imaging studies. However, the relative usefulness of these studies is still a matter of some controversy. The aim of this study was to compare the intra-observer and inter-observer reliability of plain radiographs, standard computed tomography (CT) scans and mobile CT scans in the assessment of distal radius fractures as categorized by the Fernandez classification method. The secondary objective was to compare the dosages of radiation between the different imaging modalities. Material and Methods: Sixteen fresh cadaveric wrist bones were used in this experimental study. The desired fractures were created in the bones to mimic Fernandez types I-V fractures and plain radiographs were taken in 4 views. Standard CT and mobile CT scans were also taken with the fractured bones in the same four positions. Interobserver reliability was assessed using Kappa statistics to determine the diagnostic consistency among the nine observers. Inter-observer agreement was assessed based on the Fernandez classification system diagnoses. Results: Overall, the inter-observer agreement was substantial for the Fernandez classifications (Kappa range 0.636 0.727) in all types of imaging. For intra-observer agreement, the analysis found higher agreement for both standard CT scans and mobile CT scans. The standard CT images imparted a higher average dose of radiation than both the mobile CT scans and the plain radiographs.Conclusion: The mobile CT scan can provide an alternative imaging method for precise diagnosis of distal end radius fractures, with the additional benefits of mobility and lower radiation exposure.

Remote post-mortem radiology reporting in disaster victim identification: experience gained in the 2017 Grenfell Tower disaster

On 14 June 2017 at 00:54 h, the worst residential fire since the conclusion of the Second World War broke out in Flat 16, 4th floor of the 24-storey residential Grenfell Tower Block of flats, North Kensington, West London, UK. Seventy-one adults and children died, including one stillbirth. All victims of the Grenfell Tower disaster who died at the scene underwent post-mortem computed tomography (PMCT) imaging using a mortuary-sited mobile computed tomography scanner. For the first time, to the authors’ knowledge, the disaster victim identification (DVI) radiology reporting was undertaken remote to the mortuary scanning. Over an 11-week period, 119 scans were undertaken on 16 days, with up to 18 scans a day. These were delivered to a remote reporting centre at Leicester on 13 days with between 2 and 20 scans arriving each day. Using a disaster-specific process pathway, a team of 4 reporters, with 3 support staff members, trialled a prototype INTERPOL DVI radiology reporting form and produced full radiology reports and supporting image datasets such that they were able to provide 96% of prototype DVI forms, 99% of image datasets and 86% of preliminary reports to the DVI teams in London within one working day of image receipt. This paper describes the first use of remote radiology reporting for DVI and exemplifies how remote PMCT reporting can be used to support a DVI process of this scale.

Use of a Mobile Intraoperative Computed Tomography Scanner for Navigation Registration During Laser Interstitial Thermal Therapy of Brain Tumors

In recent years laser interstitial thermal therapy (LITT) has become the ablative neurosurgical procedure of choice. Multiple methods for registration and laser fiber verification have been described, with each method requiring multiple steps and significant time expenditure. We evaluated the use of a commercially available mobile computed tomography (CT) scanner for stereotactic registration during LITT for brain tumors in an attempt to simplify the procedure and improve intraoperative awareness of laser position. This is a retrospective chart review comparing LITT of brain tumors in 23 patients undergoing a standard protocol requiring skull pins and transport of the patient to a CT suite to obtain a reference scan compared with 14 patients in whom the Medtronic O-arm was used intraoperatively for navigation registration and confirmation of laser position. Total ablation of the target was achieved in all patients with no surgical complications. Total surgery time was shorter for the O-arm group than for the standard protocol group, once experience was gained with bringing the O-arm in and out of the surgical field. Return from the magnetic resonance imaging suite to the operating roomfor repositioning of the laser was required for 1 patient in the standard protocol group, but for no patients in the O-arm group. Once experience was gained with using the O-arm, estimated surgical costs were lower for this group. Use of a mobile intraoperative CT scanner for navigation registration and confirmation of laser position during LITT may play a role in streamlining the procedure and improving patient safety and comfort.

Bedside computed tomography in traumatic brain injury: Experience of 10,000 consecutive cases in neurosurgery at a level 1 trauma center in India.

Patients with traumatic brain injury (TBI) need frequent computed tomography (CT) of the head for assessment and management. In view of the associated polytrauma, hemodynamic instability, and various in-dwelling catheters and tubes, shifting of patients for CT scans may be difficult. To assess the role of mobile CT (Ceretom®; NeuroLogica Corporation, Boston, MA, USA) in a trauma center with respect to patient management. In this retrospective study over 67 months (June 2009 to January 2015), the number of CT scans done, the time taken for CT and downtime were evaluated. Also, for the first 1000 mobile CT scans, the clinical and radiological records of all patients with TBI who underwent imaging using the mobile CT scanner in the intensive care units (ICUs) were analyzed. A total of 10,000 mobile CT scans were done on the mobile CT scanner till January 5, 2015. Of the first 1000 patients evaluated, 75.3% had severe TBI, 15.1% had moderate TBI, and 9.6% had mild TBI. 78.1% patients were on ventilator, with 80.2% requiring sedation and 8.4%, an inotropic support. An in situ intracranial pressure monitoring was present in 21.1% of patients. In all, 12.4% of patients had long-bone fractures requiring skeletal traction; and, the tube thoracostomy was in-situ in 7.4%. No adverse events related to line malfunction/pullout occurred. The mean time for the performance of imaging using the mobile CT scan was 11.6 minutes compared with 47.8 minutes when patients were shifted to a conventional CT scan suite. The machine was nonfunctional 94 times, with an average downtime of 4.2 hours (range 2-72 hours). The life-cycle cost per mobile CT scan was Rs. 1340. A mobile CT has considerably changed the management response time in the neurosurgical intensive care unit (ICU) setup and decreased patient transfer times and the associated complications. Inclusion of a mobile CT scanner in the armamentarium of a neurosurgeon as a "bedside tool" can dramatically change decision making and the response time. It should be considered as the standard of care in any large-volume emergency department or neurosurgical facility.

Demand of Innovative Services on a Computed Tomography Scan

This paper seeks to investigate the needs of service, innovative Mobile Computed Tomography (CT) Scan service, from the leading level of Neurosurgeon in Bangkok, Thailand. The research is proposed investigating Neurosurgeon’s expectations for Mobile CT Scan and current problems of CT scan operating. This is a survey research approach, performing in-depth interview which collected data from 21 Neurosurgeons, 12 hospitals in Bangkok and surrounding areas. Due to the number of samples limited, the descriptive statistics were used to analyze the data. The research address two research questions: According to the first research question, the authors’ findings that most of Neurosurgeon need to use Mobile CT Scan at Operation Room (OR), Intensive Care Unit (ICU), and Emergency Room (ER), respectively. Regarding the second research question, the authors’ analysis reveals purposes and found the current problems that when Neurosurgeon use CT Scan they faced low resolution and slice, moving unstable patients, wriggle patients, and Claustrophobia patients. Therefore, what are the findings of the survey are very useful in the design of new services for Mobile CT Scan to work in the next step.

Better Outcomes with Prehospital Stroke Thrombolysis

Investigators in Germany compared time to thrombolysis between stroke patients receiving routine care in an emergency department and those evaluated in the prehospital setting by a special ambulance called “stroke emergency mobile” or STEMO. The STEMO was staffed by a neurologist and was equipped with a mobile computed tomography scanner and a point-of-care laboratory. The unit of …

Delayed detection versus delayed occurrence of contralateral hematoma.

Dear Sir, Intraoperative or immediate development of contralateral hematoma, following decompressive craniectomy, with or without a coexisting fracture/hematoma, is a well documented entity in the literature.[1,2,3,4] Having read the following article “Contralateral delayed epidural hematoma following intra cerebral hematoma surgery” by Solomiichuk and Drizhdov,[4] had few queries/doubts. This 28-year-old male, who had a traumatic left frontal contusion with a fracture of right temporal bone, was treated by the left sided hemicraniectomy and evacuation of intracerebral haematoma in left frontal lobe. The authors have mentioned an intraoperative event of acute brain swelling, a well documented entity due to loss of tamponade effect resulting in contralateral hematomas, which warrants imaging in the immediate postoperative period.[5] However, the imaging was delayed for reasons not mentioned. On contacting the authors through the editor, the authors contended that the patient was hemodynamically unstable and that was the reason for delay in obtaining the computed tomography (CT) scan. Had the patient been hemodynamically stable, the authors too would have obtained a control CT scan immediately. Development of anisocoria is a late event in the manifestation of transtentorial herniation with other features, especially the initial clouding of consciousness being masked by an already poor preoperative Glasgow Coma Scale (GCS; 5/15). In the absence of immediate postoperative scan, the clinical and operative findings are not consistent with the term “delayed” occurrence of contralateral hematoma, for it could have developed when there was a brain swelling and was detected at a later date when all the described signs of herniation had developed. In fact, this is a case best strengthening the classical teaching of obtaining an imaging in the immediate postoperative period with the backdrop of adverse events intraoperatively (acute brain swelling), to rule in or out surgically treatable causes. However, circumstances may sometimes be unfavorable for shifting an hemodynamically unstable patient (as in the present case). This problem could possibly be avoided with widespread availability of mobile CT scanner in trauma care centers. The very aim of urgency in the setting of trauma is to have a relaxed brain at the earliest. The debate might not end here but we should aim to develop protocols for improved care especially following an adverse event.

Application of Postmortem 3D‐CT Facial Reconstruction for Personal Identification*

Postmortem computed tomography (CT) images can show internal findings related to the cause of death, and it can be a useful method for forensic diagnosis. In this study, we scanned a ready-made box by helical CT on 2-mm slices in a mobile CT scanner and measured each side of the box to assess whether reconstructed images are useful for superimposition. The mean difference between the actual measurements and the measurements on the three-dimensional (3D) reconstructed images (3D-CT images) is 0.9 mm; we regarded it as having no effect on reconstruction for the superimposition method. Furthermore, we could get 3D-CT images of the skull, which were consistent with the actual skull, indicating that CT images can be applied to superimposition for identification. This study suggested that postmortem CT images can be applied as superimpositions for unidentified cases, and thinner slices or cone beam CT can be a more precise tool.

Image-Guided Radiotherapy for Liver Cancer Using Respiratory-Correlated Computed Tomography and Cone-Beam Computed Tomography

To evaluate a novel four-dimensional (4D) image-guided radiotherapy (IGRT) technique in stereotactic body RT for liver tumors. For 11 patients with 13 intrahepatic tumors, a respiratory-correlated 4D computed tomography (CT) scan was acquired at treatment planning. The target was defined using CT series reconstructed at end-inhalation and end-exhalation. The liver was delineated on these two CT series and served as a reference for image guidance. A cone-beam CT scan was acquired after patient positioning; the blurred diaphragm dome was interpreted as a probability density function showing the motion range of the liver. Manual contour matching of the liver structures from the planning 4D CT scan with the cone-beam CT scan was performed. Inter- and intrafractional uncertainties of target position and motion range were evaluated, and interobserver variability of the 4D-IGRT technique was tested. The workflow of 4D-IGRT was successfully practiced in all patients. The absolute error in the liver position and error in relation to the bony anatomy was 8 +/- 4 mm and 5 +/- 2 mm (three-dimensional vector), respectively. Margins of 4-6 mm were calculated for compensation of the intrafractional drifts of the liver. The motion range of the diaphragm dome was reproducible within 5 mm for 11 of 13 lesions, and the interobserver variability of the 4D-IGRT technique was small (standard deviation, 1.5 mm). In 4 patients, the position of the intrahepatic lesion was directly verified using a mobile in-room CT scanner after application of intravenous contrast. The results of our study have shown that 4D image guidance using liver contour matching between respiratory-correlated CT and cone-beam CT scans increased the accuracy compared with stereotactic positioning and compared with IGRT without consideration of breathing motion.

Does imaging technology overcome problems of conventional postmortem examination?

We used a mobile computed tomography (CT) unit for postmortem examinations of deceased subjects to see how many mistakes on cause-of-death diagnoses were made in Japan. In 5 of 20 cases, the cause of death determined by CT was different from the diagnosis made by superficial postmortem examination. In one case, the superficial examination suggested no trauma, whereas a subdural hematoma was found on cranial CT images. We concluded that postmortem examinations in Japan were not effective when screening for crimes or accidents. Using a mobile CT scanner in postmortem examination may be a viable method of screening for causes of deaths, although it cannot be used as a substitute for autopsy.

Intraoperative Imaging Using a Mobile Computed Tomography Scanner

The radicality of tumour removal in patients suffering from glioma is discussed to be an important factor for longer survival times. Therefore intraoperative imaging modalities like magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) are tested in many neurosurgical facilities for clinical use. In our department a mobile CT for intraoperative applications is used for this purpose since 1999. The handling and useful application of the mobile CT scanner as well as results without intraoperative imaging are discussed. 470 CT scans with the mobile CT were accomplished, including 270 cases of neuronavigation planning, 76 cases of intraoperative scans, 48 cases of postoperative scans, 69 CT scans for stereotactic biopsy planning and control as well as 3 cases of emergency scanning in trauma patients and 4 spine applications. The results of the intraoperative CT scans are compared with those of the postoperative MRI scans. Additionally 87 patients with glioma were evaluated. These patients underwent surgery without intraoperative imaging. In 27 out of 43 patients with glioma residual tumour was detected with intraoperative CT. In 13 cases the surgery was resumed to complete resection, in 14 cases the operation was not continued due to close vicinity to eloquent areas or difficulties in image interpretation. In 44 cases the results of intraoperative CT and postoperative MRI were compared. In 6 cases the MRI demonstrated residual tumour in contrast to the results of the CT scans. In 3 cases the tumour removal could have been more complete (6.8 %). In 87 cases glioma surgery was performed without intraoperative CT. In 6 cases a more complete tumour removal could have been performed (6.9 %) according to the results of postoperative MRI. Intraoperative imaging with a mobile CT scanner is a good method for detection of residual tumour. The CT scanner can be integrated in an operative setting without problems. Although intraoperative imaging can be helpful in some selected cases, most of the neurosurgical procedures can be well performed with proper neuronavigation planning.

The use of a mobile computed tomography scanner in the pediatric intensive care unit to evaluate airway stenting and lung volumes with varying levels of positive end-expiratory pressure.

Presentation of a case report describing the use of a mobile computed tomography (CT) scanner in the pediatric intensive care unit (PICU) to radiographically evaluate tracheobronchial stenting and lung volumes while using different levels of positive end-expiratory pressure (PEEP) and positioning in a critically ill infant. Case report of a single patient. Pediatric intensive care unit in a University Hospital. A 6-month-old premature infant with bronchopulmonary dysplasia, tracheobronchomalacia, and progressive respiratory failure. CT scans of the chest were performed by using a mobile CT scanner in the PICU. Serial CT scans were performed at PEEP levels of 5, 10, 15, and 20 cm H(2)O in both the supine and prone position. Scheduled medical care and standard monitoring were continued during the course of the CT scans. Identical anatomic levels demonstrating the trachea, bronchi, and lung parenchyma were compared while different levels of PEEP and supine or prone positioning were used. From these comparisons, the level of PEEP in which lung volumes were optimized was radiographically determined. No significant changes in large airway caliber were observed. There was no difference noted between prone and supine positioning. CT scans were completed with minimal disruption to the patient's care. Mobile CT scanners can be used in the PICU for the diagnostic evaluation of critically ill children. This option allows for the continuation of medical therapies and monitoring in the intensive care setting while avoiding the potential complications of transporting a critically ill child to the radiology department. The use of mobile CT scanners may disrupt PICU routine and is more expensive than use of fixed CT scanners. Mobile CT scanners may be useful in radiographically determining the optimal level of PEEP in infants with tracheobronchomalacia and bronchopulmonary dysplasia.