Transcranial Access Using Fluoroscopic Flat Panel Detector CT Navigation

Abstract

SUMMARY:FPCT and navigation software on contemporary fluoroscopic units perform imaging of a quality comparable with conventional CT. They can accurately guide percutaneous procedures, providing live instrument visualization and the capability to re-image without patient transfer. FPCT navigation was used in the placement of a ventricular drain in a 62-year-old woman for subarachnoidrelated hydrocephalus by using an otherwise standard bedside technique. Ventriculostomy catheter placement was technically successful without complication with a catheter at the foramen of Monro.ABBREVIATIONS: DSA ϭ digital subtraction angiography; FPCT ϭ flat panel detector CT F PCT and integrated guidance software available on contemporary fluoroscopic systems emit a lower radiation dose while producing imaging of a quality comparable with that of conventional CT.1-5 They also have the ability to perform percutaneous procedures within the body, spine, and head and neck safely and accurately.4-11 FPCT demonstrates excellent spatial resolution and, though limited in subtle contrast differentiation, is of diagnostic accuracy in the assessment of general cerebral anatomy and higher attenuation features such as hemorrhage. [5][6][7][8]10,11 Beyond the ability of FPCTbased navigation to quickly and accurately target a particular focus is the provision of real-time instrument visualization using live fluoroscopic overlay and the capability of re-imaging without moving the patient, limitations of current neuronavigational programs. 10Ventricular drain catheter placement in the setting of subarachnoid hemorrhageϪrelated hydrocephalus is a common neurosurgical procedure. Performed at the bedside by using anatomic landmarks, ventriculostomy placement is safe and accurate with a low rate of complications.12-15 Given the frequent need for ventricular drain placement and the relative technical ease of the procedure, we chose it as means to demonstrate proof of principle regarding transcranial FPCT guidance. We herein describe the use of the navigation system in the placement of a ventriculostomy catheter. Case ReportA 62-year-old woman presented with altered mental status. Physical examination revealed an intubated obtunded patient with left-sided hemiplegia and equal and reactive pupils. CT of the head showed diffuse subarachnoid hemorrhage, hydrocephalus, and significant hemorrhage in the basal cisterns. CT angiography revealed a 6 ϫ 7 mm right-sided posterior communicating artery aneurysm and a 3 ϫ 2 mm left-sided middle cerebral artery aneurysm.The patient underwent emergent FPCT-guided ventriculostomy placement in the angiography suite. To minimize movement, we carefully taped her head to the table. The left scalp was prepped, and a 1-cm incision was made at the Kocher point, approximately 11 cm posterior to the glabella and 3 cm lateral to midline in the midpupillary line. A twist-drill craniostomy was performed. The dura and pia mater were cauterized and incised.Before catheter placement, an FPCT (XperCT and XperGuide; Philips Healthcare,...

Integrated cone-beam CT and fluoroscopic navigation in treatment of head and neck vascular malformations and tumors

“…This is similar to the reported accuracy of 1.1 mm in phantom studies in frameless neurosurgical intraoperative guidance systems 27. Our clinical needle tip targeting accuracy appears to be better than the recent reports of 3.0–3.5 mm error in standard and intracranial phantom studies using the same integrated 3D fluoroscopic guidance system 28 29. This discrepancy may be due to more precise needle placement with respect to the 3D overlay target by the neurointerventionalists in our study, but may also be due to the verification method used in our study—namely, a follow-up cone-beam CT.…”

Accuracy of flat panel detector CT with integrated navigational software with and without MR fusion for single-pass needle placement

“…A notable difference between the techniques that we used in this study and most stereotactic systems used for neurosurgical intracranial access are that we passed the needle freehand without any additional stabilisation of the needle. Nonetheless, the fidelity of the navigation system is sufficient for targeting larger anatomic targets such as the ventricles, or pathology such as a haematoma, and could potentially be applied to navigation towards MRI-defined targets with similar accuracy 1 3 11. This system could be applied to intracranial access in either a hybrid operating room or an interventional angiographic suite with appropriate safety precautions.…”

“…The concept of FDCT procedural guidance has been successfully applied with slight variations to percutaneous procedures in the brain, head and neck, and spine 1–3 7 8 10 11 14–16. There are some notable advantages to using FDCT guidance as opposed to conventional CT, including potentially lower radiation doses depending on individual procedure specifics and the fact that a traditional CT room stays functional for diagnostic studies 4 28 29.…”

“…The second FDCT was performed as a second error measurement and could potentially be omitted in clinical practice depending on the need for needle confirmation. One notable difference between our technique and similar procedures described in the literature is that we did not advance the needle under fluoroscopic guidance, skipping any progression views (similar to figure 2D) and instead only using the system's laser to line up the needle and advancing the needle in a single pass 1 3 11 28 32. The progression view could potentially be useful as a guide for depth if needed.…”

“…Integrated navigational software can be used to plan a needle trajectory and provide real-time guidance for percutaneous procedures throughout the body including for intracranial, spinal, and head and neck procedures 1–3 7 8 10 11 13–15. FDCT allows the performance of complex percutaneous procedures with the safety and convenience of performing these procedures in an interventional suite or hybrid operating room as opposed to a standard CT suite 1–3 8 10 11 15. FDCT data acquired at the time of or during a procedure can additionally be fused with pre-procedure MRI data to allow navigational guidance towards FDCT occult targets 2 16…”