Head Clamp Research Articles

Accuracy analysis of robotic assistant needle placement for trigeminal gasserian ganglion

To evaluate the accuracy and feasibility of a custom robot system guided by optical navigation for needle puncture on trigeminal gasserian ganglion. A synthetic human skull model was used, with plasticine placed around the skull base to imitate the human soft tissue. Cone beam CT (CBCT) scanning was performed before the operation. With image data transferred to the graphical user interface of the computer workstation, the oval foramen was selected as the target and the "skin entry point" was also determined by the surgeon on the surgical planning software. Thus the needle trajectory was eventually planned. The skull model was fixed firmly to the trial table with a head clamp and relative size of the trial table was the same as a standard operating table. Following point-based registration, the data were sent to the robot control unit. Only after the surgeon's confirmation, the needle was automatically inserted into the intended target by the robot guided by optical navigation. When the procedure was completed, the instantaneous data of the needle tip orientation acquired by navigation system was sent back to the computer workstation for accuracy verification by calculating the geometric distance between the needle tip and the planning target after matrix transformation. Subsequently, after the needle had been released, CBCT scanning was also acquired to make image fusion of the preoperative skull and the postoperative skull. The data of the needle tip orientation was acquired on the postoperative image and the accuracy was re-verified by calculating the geometric distance between the needle tip and the planning target after matrix transformation. IBM SPSS Statistics 20 was used for statistical analysis and the paired t-test was used to compare the differences in the accuracy measured by the intraoperative navigation and postoperative image fusion. All 20 interventions were successfully located in oval foramen at the first needle insertion. The mean deviation of the needle tip was (0.56±0.07) mm (measured by the navigation system) and (1.49±0.14) mm (measured by the image fusion), respectively (P<0.001). The experimental results show the robot system is efficient and reliable. The navigation accuracy is one of the most significant factors in robotic procedures.

Transfemoral Approach for Intraoperative Angiography in the Prone or Three-quarter Prone Position : A Revisited Protocol for Intracranial Arteriovenous Malformation and Fistula Surgery.

Among the different arterial accesses, the femoral access is the main approach for intraoperative angiography (IOA) performed in aprone position. Without astandardized protocol, however, the application of prone IOAs in intracranial arteriovenous malformation (AVM) or arteriovenous fistula (AVF) surgery remains limited by its procedural complexity. This study describes the detailed protocol for prone IOA through atransfemoral approach and highlights several refinements in preparing this procedure. This study retrospectively reviewed the intracranial or high cervical AVM/AVF surgical cases in which both resection and IOA were performed in the prone or three-quarter prone position. Extended femoral sheath approaches and radiolucent head clamps were used in all cases. An aneurysm clip, serving as alocalization landmark in IOA, was routinely placed within the surgical field. The IOA imaging, clinical impact of IOA, and complications related to the procedure were recorded. Atotal of six AVM and three AVF cases, operated on in the prone (n = 7) or three-quarter prone (n = 2) positions, were included. Multiple vessel injections were required in 66.7% of cases, and IOA was successfully performed in every intended vessel. All IOA images were adequate for interpretation, except for two cases in which the non-radiolucent component of the head clamp obscured the region of interest in the lateral views. Incomplete occlusion was identified in two patients, and the aneurysm clip provided precise guidance in localizing the residual nidus. Final IOA confirmed complete lesion removal in all cases, and there were no IOA-related complications. Three key steps in setting-up aprone IOA procedure for intracranial AVM/AVF surgery areproposed: (1)utilize an extended femoral sheath approach, (2)establish alocalization landmark with an aneurysm clip and (3)avoid possible image interference from the non-radiolucent component of the head clamp.

Giant Olfactory Groove Meningioma-2-Staged Approach: 2-Dimensional Operative Video.

A 42-yr-old female presented with an olfactory groove meningioma causing progressive vision loss and anosmia. Given the size of the tumor, we opted for a 2-stage surgery: endoscopic endonasal approach (EEA) followed by a craniotomy. Stage I surgery was a transcribriform transplanum EEA using a binostril 4-hand/2 surgeons (ENT and neuro) technique, with the patient positioned supine with the head slightly turned to the right side and tilted to the left, fixed in a 3-pin head clamp, under imaging guidance, in which we drilled out all the affected skull base bone, devascularized and debulked the tumor. Stage II surgery was done through a right frontotemporal craniotomy 2 mo later. The surgery and postoperative period was uneventful with no complications and no need for further reconstruction of the skull base. The patient's vision was normalized. Postoperative magnetic resonance imaging (MRI) confirmed a Simpson Grade 1 resection. The rationale behind this staged approach is that we have found when using a transcranial 1-stage approach the brain edema and necessary retraction required for resection leads to brain injury, oftentimes readily identified in the diffusion-weighted imaging MRI which are associated with different degrees of cognitive impairment. The skull base bone involved is usually not removed via transcranial approaches. Despite requiring a second surgery, this staged approach allows a true total resection (including the affected bone) and in the transcranial stage the brain is more relaxed, with less edema, reducing the need for retraction, which may lead to a better outcome. The patient has given assent and written consent for videos, images, or clinical or genetic information to be published.

Development of a pin-less reference head frame: An experimental setup and preliminary experiences

Abstract Objectives Advantages of image guidance in neurosurgical procedures are undisputed. Although some approaches of flexible technologies already exist, today's gold standard for neuronavigation is the pin-assisted head clamp fixation. A reference tool that is simpler in handling, universally available and non-invasive would be desirable. We introduce two pin-less mobile head frames and investigate their feasibility in a series of exercises. Patients and methods A head frame, which is originally used as facebow in dentistry, was modified to create 2 head frames. A sequence of exercises was designed to imitate the different movements of a patients head in a real case of emergency. The trial was subdivided in two phases each with 10 healthy participants. The requirement to each participant was to complete the sequence of exercises whilst wearing the frame. Different parameters were collected. Results The frame-to-head stability was not sufficient for the first frame. It increased significantly for the second frame, mainly due to the flexible forehead- and the occiput-band. The handling of both devices was cumbersome and time-consuming. Conclusion The sequence of exercises proved to be a suitable approach to investigate the advantages and disadvantages of the frames. The presented devices are not acceptable for emergency clinical practice yet. Further modification is necessary. Invasive pins are not mandatory for a close fit of the frame. The presented trial is superior to the investigation using an immobile skull model.

Endoscopic Endonasal Resection of Tuberculum Sellae Meningioma with Utilization of Indocyanine Green.

We present the case of a 67-year-old female with an incidental finding of a left-sided tuberculum sellae meningioma on a brain magnetic resonance imaging (MRI) for an unrelated complaint. Formal visual field testing showed a small defect in the inferior nasal and temporal fields of the left eye, compatible with mass effect on the optic nerve by the tumor.An endoscopic endonasal transtuberculum approach with decompression of the left optic nerve was performed using a standard binostril four-hand technique, with the patient positioned supine with the head turned to the right side and tilted to the left, fixed in a three-pin head clamp, under imaging guidance. After exposure, we drilled the tuberculum sellae and the floor of the sella and after opening the dura, the tumor and optic nerve came into view. The tumor was completely removed and we confirmed the patency of all perforating vessels using indocyanine green. Reconstruction was done in a multilayered fashion, using collagen matrix and a nasoseptal flap. Patient had an uneventful postoperative stay and was discharged on postoperative day 3, neurologically stable with no new hormonal deficits. Pathology report confirmed a WHO Grade I meningioma with K i -67 of 1% and 3-month postoperative MRI confirmed a gross total resection and visual fields exam showed a complete recovery. The link to the video can be found at: https://youtu.be/zRmt2aIvX5c .

Endoscopic Endonasal Approach to a Suprasellar Craniopharyngioma.

We present the case of a 57-year-old male who presented with progressive right side vision loss whose workup revealed a large suprasellar lesion with invasion of the third ventricle. The pituitary stalk was not visible.Hormonal panel showed no hormonal deficits. The initial diagnosis was of a type II transinfundibular craniopharyngioma (as classified by Kassam et al).An endoscopic endonasal transplanum transtuberculum approach was done using a standard binostril four-hand technique, with the patient positioned supine with the head turned to the right side and tilted to the left, fixed in a three-pin head clamp, under imaging guidance. The tumor was carefully dissected away from the optic apparatus while preserving the vessels, mainly the superior hypophyseal artery. The stalk was identified around the tumor and preserved. The third ventricle was entered and inspected at the end of the procedure and a near-total resection (a small residual in the right hypothalamus) with decompression of the optic apparatus was achieved. Reconstruction was done in a multilayered fashion, using collagen matrix and a nasoseptal flap. Patient had an uneventful postoperative stay and was discharged on POD 4, neurologically stable with no hormonal deficits. Pathology confirmed an adamantinomatous craniopharyngioma. Due to a small growth of the residual, patient underwent fractionated stereotactic radiation (50.4Gy in 28 sessions). He presented with panhypopituitarism 2 years after radiation therapy. At 3-month follow-up, his vision was back to normal and 6-year postoperative magnetic resonance imaging showed no signs of recurrence. The link to the video can be found at: https://youtu.be/chG7XIz7a_A .

Venous air embolism following application of Mayfield head clamp: A word of caution.

Venous air embolism following application of Mayfield head clamp: A word of caution.

Novel Hybrid Operating Table for Neurovascular Treatment.

The integration of interventional and surgical techniques is requiring the development of a new working environment equipped for the needs of an interdisciplinary neurovascular team. However, conventional surgical and interventional tables have only limited ability to provide for these needs. We have developed a concept mobile hybrid operating table that provides the ability for such a team to conduct both endovascular and surgical procedures in a single session. We developed methods that provide surgeons with angiography-guided surgery techniques for use in a conventional operating room environment. In order to design a convenient device ideal for practical use, we consulted with mechanical engineers. The mobile hybrid operating table consists of two modules: a floating tabletop and a mobile module. The basic principle of the mobile hybrid operating table is as follows: firstly, the length of the mobile hybrid operating table is longer than that of a conventional surgical table and yet shorter than a conventional interventional table. It was designed with the goal of exhaustively meeting the intensive requirements of both endovascular and surgical procedures. Its mobile module allows for the floating tabletop to be moved quickly and precisely. It is important that during a procedure, a patient can be moved without being repositioned, particularly with a catheter in situ. Secondly, a slim-profile headrest facilitates the mounting of a radiolucent head clamp system for cranial stabilization and fixation. Briefly, we have introduced a novel invention, a mobile hybrid operating table for use in an operating suite.

Refinement of the Hybrid Neuroendovascular Operating Suite: Current and Future Applications

In early-generation hybrid biplane endovascular operating rooms, switching from surgical to angiographic position is cumbersome. In this report, we highlight the unique design of a new hybrid neuroendovascular operating suite that allows surgical access to the head while keeping the biplane system over the lower body of the patient. Current and future hybrid neuroendovascular operating suite applications are discussed. We collaborated with engineers to implement the following modifications to the design of the angiographic system: translation of the bed toward the feet to allow biplane cerebral imaging in the head-side position and the biplane left-side position; translation of the base of the A-plane C-arm away from the feet to allow increased operator space at the head of the bed and to allow cerebral imaging in both the head-side and left-side positions; use of a specialized boom mount for the display panel to increase mobility; and use of a radiolucent tabletop with attachments for the headrest or radiolucent head clamp system. The modified hybrid neuroendovascular operating suite allows for seamless transition between surgical and angiographic positions within seconds, improving workflow efficiency and decreasing procedure time as compared with early-generation hybrid rooms. Combined endovascular and surgical applications are facilitated by co-locating their respective technologies and refining the ergonomics of the system to ease transition between both sets of technologies. In so doing, hybrid neuroendovascular operating suites can be anticipated to improve patient outcomes, generate novel treatment paradigms, and improve time and cost efficiency.

Awake craniotomy. A patient`s perspective.

Objective:To report the personal experiences of patients undergoing awake craniotomy for brain tumor resection.Methods:We carried out a qualitative descriptive survey of patients’ experiences with awake craniotomies for brain tumor resection. The survey was conducted through a standard questionnaire form after the patient was discharged from the hospital.Results:Of the 9 patients who met the inclusion criteria and underwent awake craniotomy, 3 of those patients reported no recollection of the operation. Five patients had auditory recollections from the operation. Two-thirds (6/9) reported that they did not perceive pain. Five patients remembered the head clamp fixation, and 2 of those patients classified the pain from the clamp as moderate. None of the patients reported that the surgery was more difficult than anticipated.Conclusion:Awake craniotomy for surgical resection of brain tumors was well tolerated by patients. Most patients reported that they do not recall feeling pain during the operation. However, we feel that further work and exploration are needed in order to achieve better control of pain and discomfort during these types of operations.

Asleep-awake-asleep craniotomy: A comparison with general anesthesia for resection of supratentorial tumors

The anesthetic plan for patients undergoing awake craniotomy, when compared to craniotomy under general anesthesia, is different, in that it requires changes in states of consciousness during the procedure.This retrospective review compares patients undergoing an asleep-awake-asleep technique for craniotomy (group AW: n=101) to patients undergoing craniotomy under general anesthesia (group AS: n=77). Episodes of desaturation (AW=31% versus AS=1%, p<0.0001), although temporary, and hypercarbia (AW=43.75mmHg versus AS=32.75mmHg, p<0.001) were more common in the AW group. The mean arterial pressure during application of head clamp pins and emergence was significantly lower in AW patients compared to AS patients (pinning 91.47mmHg versus 102.9mmHg, p<0.05 and emergence 84.85mmHg versus 105mmHg, p<0.05). Patients in the AW group required less vasopressors intraoperatively (AW=43% versus AS=69%, p<0.01). Intraoperative fluids were comparable between the two groups. The post anesthesia care unit (PACU) administered significantly fewer intravenous opioids in the AW group. The length of stay in the PACU and hospital was comparable in both groups.Thus, asleep-awake-asleep craniotomies with propofol-dexmedetomidine infusion had less hemodynamic response to pinning and emergence, and less overall narcotic use compared to general anesthesia. Despite a higher incidence of temporary episodes of desaturation and hypoventilation, no adverse clinical consequences were seen.

How effective is the local anesthetic infiltration of pin sites prior to application of head clamps: A prospective observational cohort study of hemodynamic response in patients undergoing elective craniotomy

Background:Use of Mayfield clamps is associated with potentially hazardous hemodynamic effects. Use of local anesthetic infiltration has yielded varying results in blunting of this response. The authors′ objective was to study the effect of lidocaine with adrenaline infiltration at Mayfield pin sites on hemodynamic response in comparison with no intervention.Methods:This was a prospective cohort study conducted at a tertiary care center from January 2012 to July 2012. Patents undergoing elective craniotomies over the study period were included and divided in two groups, Group A received lidocaine infiltration of the pin sites prior to insertion, while Group B did not. Hemodynamic response to pin application was then studied at various intervals.Results:A total of 30 patients were enrolled in each group. The baseline mean arterial pressure (MAP) and heart rate prior to pin placement in Groups A and B were comparable (P = 0.985 and 0.313). The MAP at 60 seconds after application of skull pins was significantly different in the two groups; 86.13 (±9.73) mmHg versus 104.03 (±12.95) mmHg (P < 0.001). However, the MAP at 30 minutes after application of skull pins in both groups was comparable (P = 0.585). The mean heart rate measured at 60 seconds after skull pin insertion in Group A was 78.23 (±7.19)/min while in Group B, it was 103.07 (±6.98)/min, the difference being statistically significant (P < 0.001).Conclusion:Hemodynamic changes due to the application of Mayfield clamps during elective craniotomies can be effectively prevented by prior lidocaine with adrenaline infiltration of the pin insertion sites.

Intraoperative forces and moments analysis on patient head clamp during awake brain surgery

In brain surgery procedures, such as deep brain stimulation, drug-resistant epilepsy and tumour surgery, the patient is intentionally awakened to map functional neural bases via electrophysiological assessment. This assessment can involve patient's body movements; thus, increasing the mechanical load on the head-restraint systems used for keeping the skull still during the surgery. The loads exchanged between the head and the restraining device can potentially result into skin and bone damage. The aim of this work is to assess such loads for laying down the requirements of a surgical robotics system for dynamic head movements compensation by fast moving arms and by an active restraint able to damp such actions. A Mayfield(®) head clamp was tracked and instrumented with strain gages (SGs). SG locations were chosen according to finite element analyses. During an actual brain surgery, displacements and strains were measured and clustered according to events that generated them. Loads were inferred from strain data. The greatest force components were exerted vertically (median 5.5N, maximum 151.87N) with frequencies up to 1.5Hz. Maximum measured displacement and velocity were 9mm and 60mm/s, with frequencies up to 2.8Hz. The analysis of loads and displacements allowed to identify the surgery steps causing maximal loads on the head-restraint device.

The Use of Intraoperative Navigation for Percutaneous Procedures at the Skull Base Including a Difficult-to-Access Foramen Ovale

We describe the use of an intraoperative CT scan obtained using the Medtronic O-arm (Littleton, Massachusetts) for image-guided cannulation of the foramen ovale not previously accessible with the use of fluoroscopy alone. Unlike previously described procedures, this technique does not require placement of an invasive head clamp and may be used with an awake patient. To describe the use of intraoperative neuronavigation for accessing skull base foramina and, specifically, cannulating of the foramen ovale during percutaneous rhizotomy procedures using an intraoperative image guidance CT scanner (Medtronic O-arm, Littleton, Massachusetts). A noninvasive Landmark Fess Strap attached to a spine reference frame was applied to the heads of 4 patients who harbored a difficult-to-access foramen ovale. An intraoperative HD3D skull base scan using a Medtronic O-arm was obtained, and Synergy Spine software was used to create 3D reconstructions of the skull base. Using image guidance, we navigated the needle to percutaneously access the foramen ovale by the use of a single tract for successful completion of balloon compression of the trigeminal nerve. All 4 patients (3 females and 1 male; ages 65-75) underwent the procedure with no complications. Based on our experience, neuronavigation with the use of intraoperative O-arm CT imaging is useful during these cases.

Accuracy of Image-Guided Pedicle Screw Placement Using Intraoperative Computed Tomography-Based Navigation With Automated Referencing, Part I: Cervicothoracic Spine

Image-guided spinal instrumentation reduces the incidence of implant misplacement. To assess the accuracy of intraoperative computed tomography (iCT)-based neuronavigation (iCT-N). In 35 patients (age range, 18-87 years), a total of 248 pedicle screws were placed in the cervical (C1-C7) and upper and midthoracic (T1-T8) spine. An automated iCT registration sequence was used for multisegmental instrumentation, with the reference frame fixed to either a Mayfield head clamp and/or the most distal spinous process within the instrumentation. Pediculation was performed with navigated drill guides or Jamshidi cannulas. The angular deviation between navigated tool trajectory and final implant positions (evaluated on postinstrumentation iCT or postoperative CT scans) was calculated to assess the accuracy of iCT-N. Final screw positions were also graded according to established classification systems. Mean follow-up was 16.7 months. Clinically significant screw misplacement or iCT-N failure mandating conversion to conventional technique did not occur. A total of 71.4% of patients self-rated their outcome as excellent or good at 12 months; 99.3% of cervical screws were compliant with Neo classification grades 0 and 1 (grade 2, 0.7%), and neurovascular injury did not occur. In addition, 97.8% of thoracic pedicle screws were assigned grades I to III of the Heary classification, with 2.2% grade IV placement. Accuracy of iCT-N progressively deteriorated with increasing distance from the spinal reference clamp but allowed safe instrumentation of up to 10 segments. Image-guided spinal instrumentation using iCT-N with automated referencing allows safe, highly accurate multilevel instrumentation of the cervical and upper and midthoracic spine. In addition, iCT-N significantly reduces the need for reregistration in multilevel surgery.

Mayfield head clamp and intracranial epidural hematoma

Dear Editor, Having read with interest, the recent paper by Lee and Lin [1], “The use of the three-pronged Mayfield head clamp resulting in an epidural hematoma in an adult”, we would like to make a few observations based on our previously experience [2]. Firstly, the authors said that intracranial epidural hematomas related to the use of Mayfield has not been published in adults”. We recently published the case of a 19-year-old young admitted for a endoscopic third ventriculostomy who developed an epidural hematoma due to the penetration of the skull by a pin, and review the complications in adult patients, resulting from the use of this type of head holder and found other similar two cases in patients 23 and 24 years of age [3, 4]. Second, the neurosurgeons know the importance of correct positioning of the pins; in the case described by Lee and Lin [1], we can see that the pin was placed on the temporal squama and in this location the skull can be very thin, and should be avoided as possible skull-clamp pin-location sites. And finally, in our case, the epidural hematoma and the perforation of the skull were placed on the parietal bone, which was very thin due to the chronic hypertension of the patient [2].

Neck position affects the dimensions of the rat cervical esophagus

Might esophageal structure allow dimensional alterations? The rat esophagus has elastic fibers, skeletal muscle and keratinized epithelium. Will they shorten as the neck flexes and lengthen as it hyperextends? In eight adult female rats under pentobarbital six dots of dye were placed rostrocaudally on the cervical esophagus. When prone on a flat surface the neck was flexed to about 6° short of perpendicular (84° ± 4° s.d.) and maintained by a head clamp. Greater flexion caused the chin to mask the most rostral dot. Interdot measurements were made using a dividers and digital micrometer. A 1 cm diameter vial was then placed under the shoulders. The measurements were repeated with the neck hyperextended to about 6° below 180°. Paired “t”‐tests compared distances between adjacent dots. The paired measurements (mm) were: 1.71 ± 0.26 vs 2.58 ± 0.40; 1.69 ± 0.21 vs 2.48 ± 0.29; 2.69 ± 0.40 vs 3.71 ± 0.61; 1.99 ± 0.26 vs 2.43 ± 0.23; 1.95 ± 0.25 vs 2.34 ± 0.31. As it lengthened the esophagus narrowed. At the level of the rostralmost and caudalmost dots its widths were 2.91 ± 0.28 vs 2.67 ± 0.23 and 2.76 ± 0.19 vs 2.21 ± 0.16. All differences but the rostralmost width were significant (P &lt; 0.001). The cervical esophagus changes length and width as the neck moves. This is also likely in man. On looking down at one's plate while eating, esophageal dimensions and motility might differ from when one swallows while looking up at the waiter.

Intraoperative computed tomography angiography with computed tomography perfusion imaging in vascular neurosurgery: feasibility of a new concept

In vascular neurosurgery, there is a demand for intraoperative imaging of blood vessels as well as for rapid information about critical impairment of brain perfusion. This study was conducted to analyze the feasibility of intraoperative CT angiography and brain perfusion mapping using an up-to-date multislice CT scanner in a prospective pilot series. Ten patients with unruptured aneurysms underwent intraoperative scanning with a 40-slice sliding-gantry CT scanner. Multimodal CT acquisition was obtained in 8 patients consisting of dynamic perfusion CT (PCT) scanning followed by intracranial CT angiography. Two of these patients underwent CT angiography and PCT 2 times in 1 session as a control after repositioning cerebral aneurysm clips. In another 2 patients, CT angiography was performed alone. The quality of all imaging obtained was assessed in a blinded consensus reading performed by an experienced neurosurgeon and an experienced neuroradiologist. A 6-point scoring system ranging from excellent to insufficient was used for quality evaluation of PCT and CT angiography. In 9 of 10 PCT data sets, the quality was rated excellent or good. In the remaining case, the quality was rated insufficient for diagnostic evaluation due to major streak artifacts induced by the titanium pins of the head clamp. In this particular case, the quality of the related CT angiography was rated good and sufficient for intraoperative decision making. The quality of all 12 CT angiography data sets was rated excellent or good. In 1 patient with an anterior communicating artery aneurysm, PCT scanning led to a repositioning of the clip because of an ischemic pattern of the perfusion parameter maps due to clip stenosis of an artery. The subsequent PCT scan obtained in this patient revealed an improved perfusion of the related vascular territory, and follow-up MR imaging showed only minor ischemia of the anterior cerebral artery territory. Intraoperative CT angiography and PCT scanning were shown to be feasible with short acquisition time, little interference with the surgical workflow, and very good diagnostic imaging quality. Thus, these modalities might be very helpful in vascular neurosurgery. Having demonstrated their feasibility, the impact of these methods on patients' outcomes has now to be analyzed prospectively in a larger series.

The use of the three-pronged Mayfield head clamp resulting in an intracranial epidural hematoma in an adult patient

Complications from the use of a three-pronged Mayfield head clamp have been reported in the pediatric population, usually in children with intracranial pathology or hydrocephalus resulting in a thinner skull. We report the occurrence of an intracranial epidural hematoma in an adult patient without any prior intracranial pathology after the use of a Mayfield head clamp during posterior cervical spine surgery. The purpose of the study was to report an occurrence of epidural hematoma from the use of a Mayfield head clamp in an adult patient and to review the literature. The diagnosis of intracranial epidural hematoma should be considered in the presence of persistent headache and nausea after the use of a head clamp in spinal or intracranial surgery.

Mobile Computed Tomography : Early Experience in Korea

With improved technology, the values of intraoperative computed tomography (iCT) have been reevaluated. We describe our early clinical experience with a mobile CT (mCT) system for iCT and discuss its clinical applications, advantages and limitations. Compared with intraoperative magnetic resonance imaging, this mCT system has no need for major reconstruction of a preexisting operating room for shielding, or for specialized instruments or equipment. Patients are placed on a radiolucent head clamp that fits within the gantry. Because it consists simply of a scanner and a workstation, it can be moved between locations such as an operating room, an intensive care unit (ICU) or an emergency room without difficulty. Furthermore, it can achieve nearly all types of CT scanning procedures such as enhancement, temporal bone imaging, angiography and three-dimensional reconstruction. For intracranial surgery, mCT can be used for intraoperative real-time neuronavigation by interacting with preoperative images. It can also be used for intraoperative confirmation of the extent of resection of intracranial lesions and for immediate checks for preventing intraoperative unexpected accidents. Therefore, the goals of maximal resection or optimal treatment can be achieved without any guesswork. Furthermore, mCT can achieve improved patient care with safety and faster diagnosis for patients in an ICU who might be subjected to a ventilator and/or various monitoring devices. Our initial experience demonstrates that mCT with high-quality imaging offers very useful information in various clinical situations.