New-generation tyrosine kinase inhibitor-associated asymptomatic cerebrovascular stenosis: two illustrative cases.

New-generation tyrosine kinase inhibitors (TKIs), nilotinib and ponatinib, for chronic myelogenous leukemia (CML) have been reported to cause symptomatic cerebral ischemia. Herein, we report two patients with asymptomatic cerebral artery stenosis associated with these TKIs, as a previously unreported finding. Both patients were in their 40 s and administered new-generation TKIs without vascular risk factors. New-generation TKIs for CML can cause major cerebrovascular stenosis without any symptoms. Examining the neck and intracranial arteries using magnetic resonance angiography and carotid ultrasonography may prevent future cerebral infarctions associated with these TKIs.

Analysis of key clinical features for achieving complete remission in stage III and IV non-small cell lung cancer patients.

BACKGROUND: Although development of immune checkpoint inhibitors and various molecular target agents has extended overall survival time (OS) in advanced non-small cell lung cancer (NSCLC), a complete cure remains rare. We aimed to identify features and treatment modalities of complete remission (CR) cases in stages III and IV NSCLC by analyzing long-term survivors whose OS exceeded 3 years. METHODS: From our hospital database, 1,699 patients, registered as lung cancer between 1st Mar 2004 and 30th Apr 2011, were retrospectively examined. Stage III or IV histologically or cytologically confirmed NSCLC patients with chemotherapy initiated during this period were enrolled. A Cox proportion hazards regression model was used. Data collection was closed on 13th Feb 2017. RESULTS: There were 164 stage III and 279 stage IV patients, including 37 (22.6%) and 51 (18.3%) long-term survivors and 12 (7.3%) and 5 (1.8%) CR patients, respectively. The long-term survivors were divided into three groups: 3 ≤ OS < 5 years, 5 years ≤ OS with tumor, and 5 years ≤ OS without tumor (CR). The median OS of these groups were 1,405, 2,238, and 2,876 days in stage III and 1,368, 2,503, and 2,643 days in stage IV, respectively. The mean chemotherapy cycle numbers were 16, 20, and 10 in stage III and 24, 25, and 5 in stage IV, respectively. In the stage III CR group, all patients received chemoradiation, all oligometastases were controlled by radiation, and none had brain metastases. Compared with non-CR patients, the stage IV CR patients had smaller primary tumors and fewer metastases, which were independent prognostic factors for OS among long-term survivors. The 80% stage IV CR patients received radiation or surgery for controlling primary tumors, and the surgery rate for oligometastases was high. Pathological findings in the stage IV CR patients revealed that numerous inflammatory cells existed around and inside resected lung and brain tumors, indicating strong immune response. CONCLUSIONS: Multiple line chemotherapies with primary and oligometastatic controls by surgery and/or radiation might achieve cure in certain advanced NSCLC. Cure strategies must be changed according to stage III or IV. This study was retrospectively registered on 16th Jun 2019 in UMIN Clinical Trials Registry (number UMIN000037078).

Wedge-technique for transposition of the vertebral artery in microvascular decompression for hemifacial spasm: technical nuances and surgical outcomes.

BACKGROUND: Transposition of the vertebral artery (VA) for microvascular decompression for hemifacial spasm (HFS) is often challenging. Various procedures have been proposed to transpose the immobile tortuous VA that cannot be decompressed satisfactorily in the usual manner. METHODS: A Teflon piece that is cut into a wedge shape was used for transposition of the VA as an offending artery in HFS. One or more wedge-shaped Teflon pieces were simply inserted into a small space between the VA and the brainstem or cerebellar hemisphere without any contact with the entry into the root exit zone (REZ) of the facial nerve. A minimal space can be created by slight mobilization of the VA through rostral or caudal, or in between to the lower cranial nerves (LCNs). In cases of a hypertrophic VA that is hard to mobilize, two or more rigid wedge-shaped Teflon pieces that are coated by fibrin glue can be applied to obtain adequate mobilization of the VA. Moreover, a much harder Teflon bar, which is bent into a V shape, can be used in cases of an immobile VA. Once the VA is transposed to an appropriate position, the Teflon, VA, and contacted surface of the brainstem are fixed together by drops of fibrin glue. RESULTS: The offending arteries were VA-posterior inferior cerebellar artery (PICA) in eight cases, VA in four cases, PICA in four cases, VA-anterior inferior cerebellar artery (AICA) in one case, and AICA in one case. Eighteen cases of HFS were successfully treated using the "Wedge technique." Symptoms disappeared within 2 weeks in all patients. Transient facial nerve palsy developed in one case, and transient hoarseness developed in one case. CONCLUSIONS: The wedge technique is a simple straight-line maneuver that facilitates sufficient transposition of the VA without any related complications. This technique is also useful for other large offending vessels, such as the anterior or posterior inferior cerebellar arteries, which are hard to mobilize due to the torque of the vessels.

How I do it: endoscopic microvascular decompression for hemifacial spasm associated with the vertebral artery.

BACKGROUND: Microvascular decompression (MVD) of hemifacial spasm (HFS) associated with the vertebral artery (VA) shows higher rates of incomplete cure and complications compared to non-VA-related HFS. METHOD: Purely endoscopic MVD for VA-associated HFS via a retrosigmoid keyhole was performed. Neurovascular conflicts by a directly offending artery and VA around the root exit zone of the facial nerve were clearly demonstrated under 30° endoscopic view without significant cerebellar retraction. The VA and directly offending artery were safely transposed with preservation of perforators under excellent view. CONCLUSION: Endoscopic MVD offers reliable decompression for VA-associated HFS with minimal invasiveness.

Predicting Intracerebral Hemorrhage Growth With the Spot Sign: The Effect of Onset-to-Scan Time.

BACKGROUND AND PURPOSE: Hematoma expansion after acute intracerebral hemorrhage is common and is associated with early deterioration and poor clinical outcome. The computed tomographic angiography (CTA) spot sign is a promising predictor of expansion; however, frequency and predictive values are variable across studies, possibly because of differences in onset-to-CTA time. We performed a patient-level meta-analysis to define the relationship between onset-to-CTA time and frequency and predictive ability of the spot sign. METHODS: We completed a systematic review for studies of CTA spot sign and hematoma expansion. We subsequently pooled patient-level data on the frequency and predictive values for significant hematoma expansion according to 5 predefined categorized onset-to-CTA times. We calculated spot-sign frequency both as raw and frequency-adjusted rates. RESULTS: Among 2051 studies identified, 12 met our inclusion criteria. Baseline hematoma volume, spot-sign status, and time-to-CTA were available for 1176 patients, and 1039 patients had follow-up computed tomographies for hematoma expansion analysis. The overall spot sign frequency was 26%, decreasing from 39% within 2 hours of onset to 13% beyond 8 hours (P<0.001). There was a significant decrease in hematoma expansion in spot-positive patients as onset-to-CTA time increased (P=0.004), with positive predictive values decreasing from 53% to 33%. CONCLUSIONS: The frequency of the CTA spot sign is inversely related to intracerebral hemorrhage onset-to-CTA time. Furthermore, the positive predictive value of the spot sign for significant hematoma expansion decreases as time-to-CTA increases. Our results offer more precise risk stratification for patients with acute intracerebral hemorrhage and will help refine clinical prediction rules for intracerebral hemorrhage expansion.

Acute subdural hematoma caused by a ruptured cavernous internal carotid artery giant aneurysm following abducens nerve palsy: case report and review of the literature.

The authors report a 61-year-old female patient with a giant cavernous aneurysm in the right internal carotid artery (ICA) leading to acute subdural hematoma (ASDH) 7 days after the occurrence of abducens nerve palsy. She underwent ICA occlusion associated with high-flow bypass. In all five reported patients with a cavernous ICA aneurysm causing ASDH, the size of the aneurysm was giant and cranial nerve signs preceded the rupture. When a patient with a symptomatic cavernous ICA giant aneurysm experiences sudden-onset headache and/or consciousness disturbance, rupture of the aneurysm should be differentiated, even though a cavernous ICA aneurysm rarely causes ASDH.

Identification of the internal carotid artery at the superior part of the cavernous sinus during endoscopic endonasal cavernous sinus tumor surgery.

BACKGROUND: Identification of the internal carotid artery (ICA) is essential for successful endoscopic endonasal cavernous sinus tumor surgery. This study aimed to develop a method for identifying the ICA in cavernous sinus tumors at the superior part of the cavernous sinus. METHODS: Ten fresh cadavers were studied with a 4-mm 0° and 30° endoscope to identify surgical landmarks of the ICA in the cavernous sinus. Clinical cases of cavernous sinus tumors were surgically treated using an endoscopic transpterygoid approach. RESULTS: Anatomical study indicated the ICA at the superior part of the cavernous sinus can be identified using three steps: 1) exposure of the optic nerve sheath by drilling the optic canal; 2) identification of the proximal orifice of the optic nerve sheath at the transition of the optic nerve sheath and dura mater of the tuberculum sellae; and 3) identification of the clinoid segment of the ICA at the distal dural ring just below the proximal orifice of the optic nerve sheath. Although the ICA was encased and transposed by tumors in preliminary surgical cases, the clinoid segment of the ICA was safely exposed at the superior part of the cavernous sinus using this method. CONCLUSIONS: Dural structures around the cavernous sinus are key to identifying the ICA at the superior part of the cavernous sinus. This method is expected to reduce the risk of ICA injury during endoscopic endonasal surgery for cavernous sinus tumors.

Risks and benefits of CT angiography in spontaneous intracerebral hemorrhage.

BACKGROUND: Few studies have examined the risk of computed tomography angiography (CTA) during the acute phase of spontaneous intracerebral hemorrhage (ICH), while the benefits of CTA in ICH have been well-documented. The present study investigated both the benefits of identifying spot signs, which are supposed to indicate hematoma enlargement after admission, and risks of CTA performed during the acute phase of ICH. METHODS: We retrospectively assessed 323 consecutive patients with spontaneous ICHs admitted to our hospital between April 2009 and March 2012 and who underwent CTA on admission. RESULTS: In 80 patients (24.7 %), spot signs were demonstrated on CTA source images. Multivariate analysis revealed two independent factors correlated with presence of the spot sign: age and hematoma volume (p < 0.05 each). The presence of spot sign was associated with unfavorable outcomes at discharge and hematoma growth after admission (p < 0.05 each). Adverse events related to CTA occurred in 17 patients (5.2 %), including transient renal dysfunction in 16 patients and allergy to contrast medium in one patient. All adverse events completely resolved within 1 week. CONCLUSIONS: Presence of the spot sign indicated the possibility of hematoma growth and unfavorable outcomes. A small number of adverse events occurred in association with CTA, but without any permanent deficits. Given the potential benefits and risks, we believe that CTA performed at admission in all patients with ICH is beneficial to improve the outcomes.

The striate artery, hematoma, and spot sign on coronal images of computed tomography angiography in putaminal intracerebral hemorrhage.

BACKGROUND AND PURPOSE: A spot sign is a bright spot on computed tomography angiography source images, which is predictive of hematoma growth in spontaneous intracerebral hemorrhage, although the cause of the spot sign is unclear. Our aim was to investigate the spot sign seen on computed tomography angiography and a striate artery, which is a presumed site of intracerebral hemorrhage bleeding origin in the putamen. METHODS: In consecutive cases of spontaneous intracerebral hemorrhage in the putamen, spot signs and striate arteries were evaluated. Coronal reformat images of computed tomography angiography were created to visualize the striate arteries. Acute deterioration, defined as hematoma enlargement, emergency hematoma removal, or death within the day of admission, was reviewed. RESULTS: Of the 141 patients undergoing computed tomography angiography, 15 of the 30 patients (50%) who had spot signs showed an intrahematoma striate artery (termed spot and tail sign), which was a linear density extending from the middle cerebral artery toward the spot sign. Acute deterioration occurred more frequently in patients who had a spot and tail sign compared with patients who had spot signs without intrahematoma striate arteries (P<0.05). Multivariate analysis revealed that hematoma volume, spot signs, and intrahematoma striate arteries were independent predictors of acute deterioration (P<0.05). CONCLUSIONS: The presence of a spot and tail sign, assumed to indicate active bleeding from the striate artery, could be a more sensitive predictor of acute deterioration than the presence of a simple spot sign.

Partial splenic embolisation using n-butyl cyanoacrylate: intraprocedural evaluation by magnetic resonance imaging.

OBJECTIVES: To evaluate the use of diffusion-weighted imaging (DWI) for estimating infarcted splenic volume during partial splenic embolisation (PSE) using n-butyl cyanoacrylate (NBCA). METHODS: Twenty consecutive patients (57.2 ± 11.7 years) with hypersplenism underwent PSE. Intrasplenic branches were embolised using NBCA via a 2.1-French microcatheter aiming at infarction of 50 to 80 % of total splenic volume. Immediately after PSE, signal intensities (SI) of embolised and non-embolised splenic parenchyma were measured on DWI. Semi-automated volumetry (SAV) on DWI was compared with conventional manual volumetry (MV) on contrast-enhanced CT 1 week after PSE. Platelet counts were recorded before and after PSE. RESULTS: The SI on DWI in the embolised parenchyma decreased significantly (P < 0.01) to 24.7 ± 8.1 % as compared to non-embolised parenchyma. SAV and MV showed a strong correlation (r = 0.913 before PSE, r = 0.935 after PSE, P < 0.01) and significant (P < 0.01) reduction of normal splenic volume was demonstrated on both SAV (71.9 ± 12.4 %) and MV (73.6 ± 9.3 %) after PSE. Based on the initial SAV, three patients (15 %) underwent additional branch embolisation to reach sufficient infarction volume. Platelet counts elevated significantly (522.8 ± 209.1 %, P < 0.01) by 2 weeks after PSE. No serious complication was observed. CONCLUSION: Immediate SI changes on DWI after PSE allowed semi-automated splenic volumetry on site. KEY POINTS: • Partial splenic embolisation (PSE) is an important interventional technique for hypersplenism • Diffusion-weighted MR reveals an immediate decrease in signal in the embolised parenchyma • Such signal reduction permits semi-automated splenic volumetry on site. • This allows precise quantification of the amount of parenchyma infarcted, avoiding additional PSE.

Neuroprotective effects of liraglutide for stroke model of rats.

The number of diabetes mellitus (DM) patients is increasing, and stroke is deeply associated with DM. Recently, neuroprotective effects of glucagon-like peptide-1 (GLP-1) are reported. In this study, we explored whether liraglutide, a GLP-1 analogue exerts therapeutic effects on a rat stroke model. Wistar rats received occlusion of the middle cerebral artery for 90 min. At one hour after reperfusion, liraglutide or saline was administered intraperitoneally. Modified Bederson's test was performed at 1 and 24 h and, subsequently, rats were euthanized for histological investigation. Peripheral blood was obtained for measurement of blood glucose level and evaluation of oxidative stress. Brain tissues were collected to evaluate the level of vascular endothelial growth factor (VEGF). The behavioral scores of liraglutide-treated rats were significantly better than those of control rats. Infarct volumes of liraglutide-treated rats at were reduced, compared with those of control rats. The level of derivatives of reactive oxygen metabolite was lower in liraglutide-treated rats. VEGF level of liraglutide-treated rats in the cortex, but not in the striatum significantly increased, compared to that of control rats. In conclusion, this is the first study to demonstrate neuroprotective effects of liraglutide on cerebral ischemia through anti-oxidative effects and VEGF upregulation.

[Visualization of Cerebrospinal Fluid Dynamics by Respiratory Motion Using Phase Dispersion: Optimization of Spatial and Temporal Resolutions].

PURPOSE: The purpose of this study was to investigate the optimal spatial resolution and temporal resolution of dynamic improved motion-sensitized driven-equilibrium steady-state free precession for visualization of respiratory-driven cerebrospinal fluid (CSF) dynamics. METHODS: We investigated the differences in the visualization using the midsagittal cross-sections of nine healthy volunteers by three imaging conditions. (A: spatial resolution 0.49×0.49×5 mm, temporal resolution 1000 ms; B: 0.49×0.49×5 mm, 430 ms; and C: 0.78×0.78×5 mm, 200 ms). First, we calculated the CSF of the third and fourth ventricles and the signal-to-noise ratio (SNR) of the pons. Next, we calculated the signal intensity ratio (SIR) of the CSF flowing at 10 cm/s or more and the CSF flowing at 10 cm/s or less due to respiration. We also calculated the difference between the inspiration and expiration SIR. Furthermore, 1) the presence of flow in the third and fourth ventricles centered on the cerebral aqueduct and 2) the change in flow due to respiration was investigated by a three-point scale visual assessment by seven radiological technologists. RESULTS: The SNR was the highest in A, the next highest in B, and the lowest in C in all cases. There were significant differences between A and B, and A and C in CSF of the third and fourth ventricles. However, there was no significant difference between B and C. The CSF signal intensity changed with respiration. The SIR of the third ventricle was higher on inspiration and lower on expiration. Conversely, the SIR of the fourth ventricle was lower on inspiration and higher on expiration. There was a significant difference between A and C and B and C in each SIR (p<0.05). The difference between inspiration and expiration SIR was the highest in B, the next highest in A, and the lowest in C in both the third and fourth ventricles. Significant differences were found between A and C, and between B and C (p<0.05). There was no significant difference in the presence of flow in the third and fourth ventricles centered on the cerebral aqueduct (p=0.264). On the other hand, there was a significant difference between the imaging conditions in the change in flow due to respiration, with B having a higher value than the others (p<0.001). CONCLUSION: The optimal spatial and temporal resolutions were 0.49×0.49×5 mm and 430 ms, respectively. The results also suggest that it is important to carefully set the imaging conditions for the spatial and temporal resolutions because of the use of phase dispersion in this method.

Intraoperative MR Imaging during Glioma Resection.

One of the major issues in the surgical treatment of gliomas is the concern about maximizing the extent of resection while minimizing neurological impairment. Thus, surgical planning by carefully observing the relationship between the glioma infiltration area and eloquent area of the connecting fibers is crucial. Neurosurgeons usually detect an eloquent area by functional MRI and identify a connecting fiber by diffusion tensor imaging. However, during surgery, the accuracy of neuronavigation can be decreased due to brain shift, but the positional information may be updated by intraoperative MRI and the next steps can be planned accordingly. In addition, various intraoperative modalities may be used to guide surgery, including neurophysiological monitoring that provides real-time information (e.g., awake surgery, motor-evoked potentials, and sensory evoked potential); photodynamic diagnosis, which can identify high-grade glioma cells; and other imaging techniques that provide anatomical information during the surgery. In this review, we present the historical and current context of the intraoperative MRI and some related approaches for an audience active in the technical, clinical, and research areas of radiology, as well as mention important aspects regarding safety and types of devices.

Nontraumatic Internal Carotid Aneurysms in the Paranasal Sinuses Presenting with Epistaxis: A Case Report.

Epistaxis due to rupture of a nontraumatic internal carotid artery (ICA) aneurysm in the paranasal sinus has rarely been reported. Here, we report a case of double ICA aneurysms located within both the sphenoid and ethmoid sinuses. A 78-year-old woman presented with recurrent massive epistaxis. Magnetic resonance angiogram (MRA) and cerebral angiogram showed two ICA aneurysms: one protruded into the sphenoid sinus and the other protruded into the ethmoid sinus. Intra-aneurysmal coil embolization was performed for both aneurysms. The patient recovered completely, and a follow-up MRA 3 years later showed no recurrence of the aneurysms. Intra-aneurysmal coil embolization is an option of treatment for an ICA aneurysm filling the paranasal sinus.

Evaluation of Cardiac- and Respiratory-driven Cerebrospinal Fluid Motions by Applying the S-transform to Steady-state Free Precession Phase Contrast Imaging.

PURPOSE: To extract the status of hydrocephalus and other cerebrospinal fluid (CSF)-related diseases, a technique to characterize the cardiac- and respiratory-driven CSF motions separately under free breathing was developed. This technique is based on steady-state free precession phase contrast (SSFP-PC) imaging in combination with a Stockwell transform (S-transform). METHODS: 2D SSFP-PC at 3 T was applied to measure the CSF velocity in the caudal-cranial direction within a sagittal slice at the midline (N = 3) under 6-, 10-, and 16-s respiratory cycles and free breathing. The frequency-dependent window width of the S-transform was controlled by a particular scaling factor, which then converted the CSF velocity waveform into a spectrogram. Based on the frequency bands of the cardiac pulsation and respiration, as determined by the electrocardiogram (ECG) and respirator pressure sensors, Gaussian bandpass filters were applied to the CSF spectrogram to extract the time-domain cardiac- and respiratory-driven waveforms. RESULTS: The cardiac-driven CSF velocity component appeared in the spectrogram clearly under all respiratory conditions. The respiratory-driven velocity under the controlled respiratory cycles was observed as constant frequency signals, compared to a time-varying frequency signal under free breathing. When the widow width was optimized using the scale factor, the temporal change in the respiratory-driven CSF component was even more apparent under free breathing. CONCLUSION: Velocity amplitude variations and transient frequency changes of both cardiac- and respiratory-driven components were successfully characterized. These findings indicated that the proposed technique is useful for evaluating CSF motions driven by different cyclic forces.

Posterior Fossa Chronic Subdural Hematoma Associated with Supratentorial Chronic Subdural Hematoma.

OBJECTIVE: Chronic subdural hematoma (CSDH) in the posterior fossa has until now been reported in only 16 patients. This study clarified the frequency and characteristics of the posterior fossa CSDH through the use of magnetic resonance imaging (MRI) in patients with supratentorial CSDH. METHODS: We retrospectively examined presurgical MRI findings in patients with supratentorial CSDH who underwent surgery between 2006 and 2020. RESULTS: MRI revealed posterior fossa CSDH in 24 (7.3%) of 329 patients. Multivariable analyses demonstrated that anticoagulant treatment (P = 0.033, odds ratio [OR] 3.53), cerebrospinal fluid leak (P = 0.001, OR 18.5), and lack of previous trauma 3 weeks or more before admission (P = 0.027, OR 3.03) were risk factors of posterior fossa CSDH. Computed tomography could not show the hematomas in 20 patients (83.3%). All the posterior fossa CSDHs improved after supratentorial CSDH drainage. CONCLUSIONS: Posterior fossa CSDH was observed on MRI in a minority of patients with supratentorial CSDH. Although most patients with posterior fossa CSDH had good outcomes, large posterior fossa CSDH sometimes must be treated surgically, according to previous reports.

Multimodality imaging suite: neo-futuristic diagnostic imaging operating suite marks a significant milestone for innovation in medical technology.

In February 2006, Tokai University Hospital officially opened the imaging operation suite, which is the first hybrid neurosurgical procedure suite to combine magnetic resonance imaging, computed tomography and angiography with a neurosurgical operating room. Here, we describe the concept of the imaging operation suite and the first 4 years' experience using this suite.

Improving patient safety in the intra-operative MRI suite using an on-duty safety nurse, safety manual and checklist.

This paper describes the use of an on-duty safety nurse, a surgical safety manual and a checklist as an essential precursor to evaluating how these approaches affect surgical quality, communication in surgery crews and contribute to the safety of surgical care in the intra-operative magnetic resonance imaging (MRI) suite.

Fusing of Preoperative Magnetic Resonance and Intraoperative O-arm Images in Deep Brain Stimulation Enhance Intuitive Surgical Planning and Increase Accuracy of Lead Placement.

Intraoperative fluoroscopy and microelectrode recording (MER) are useful techniques for guiding lead placement in deep brain stimulation (DBS). Recent advances in magnetic resonance imaging (MRI) have enabled information on the location of the basal ganglia, as the target of DBS, to be obtained preoperatively. However, intraoperative images with few artifacts are required to enable accurate fusion of preoperative imaging data with intraoperative lead position data. With our method, we first fuse preoperative MRI and pre-frame fixed computed tomography (CT) images, then fuse the CT images exactly after mounting the frame, using this fusion image as a platform image. Compared with before and after frame fixation, the pre-frame fixed CT has less artifacts, facilitating the identification of soft tissues such as the ventricles and cortical surface on pre-frame fixed CT images. By fusing the structural information for these soft tissues between pre-frame fixed CT and MR images, this fusion process can provide improved accuracy that is intuitively understood by the surgeon. Using platform images, surgical planning and intraoperative lead positioning can then be evaluated on the same coordinate axis. Positional data on the lead acquired as three-dimensional (3D) data are then added to the platform image. The proposed surgical steps permit the acquisition of accurate lead position data.