In this paper, signal-to-noise ratio (SNR) and signal different-to-noise ratio (SDNR) methods were used to compare image quality using two different radiofrequency coils. The two coil types included an eight-element phased-array coil and a quadrature birdcage head coil with endcap and the comparison studies performed on a uniform cylindrical phantom and volunteer respectively. The results showed phased-array coil have advantages and proved effectiveness of the method in the evaluation and selection of coils.
Adult ; Cerebral Angiography ; methods ; Humans ; Magnetic Resonance Angiography ; methods ; Male ; Signal-To-Noise Ratio

OBJECTIVETo discuss the feasibility and clinical value of high-resolution magnetic resonance vessel wall imaging (HRMR VWI) for intracranial arterial stenosis.

DATE SOURCESWe retrieved information from PubMed database up to December 2015, using various search terms including vessel wall imaging (VWI), high-resolution magnetic resonance imaging, intracranial arterial stenosis, black blood, and intracranial atherosclerosis.

STUDY SELECTIONWe reviewed peer-reviewed articles printed in English on imaging technique of VWI and characteristic findings of various intracranial vasculopathies on VWI. We organized this data to explain the value of VWI in clinical application.

RESULTSVWI with black blood technique could provide high-quality images with submillimeter voxel size, and display both the vessel wall and lumen of intracranial artery simultaneously. Various intracranial vasculopathies (atherosclerotic or nonatherosclerotic) had differentiating features including pattern of wall thickening, enhancement, and vessel remodeling on VWI. This technique could be used for determining causes of stenosis, identification of stroke mechanism, risk-stratifying patients, and directing therapeutic management in clinical practice. In addition, a new morphological classification based on VWI could be established for predicting the efficacy of endovascular therapy.

CONCLUSIONSThis review highlights the value of HRMR VWI for discrimination of different intracranial vasculopathies and directing therapeutic management.

Carotid Stenosis ; diagnosis ; Cerebral Angiography ; methods ; Humans ; Intracranial Arteriosclerosis ; diagnosis ; Magnetic Resonance Angiography ; methods

BACKGROUNDFenestration of the proximal anterior cerebral artery (ACA) A1 segment is a rare anatomic variation. The purpose of the this study was to report the incidence of fenestration in the proximal segment of the anterior cerebral artery and to delineate its configurations on cranial MR angiography.

METHODSMagnetic resonance angiography (MRA) was performed in 762 patients using 1.5 T imagers during the period July 2007 through September 2008. All images were obtained by the three-dimensional time-of-flight (3D TOF) technique. Volume rendering (VR) images in the horizontal rotation view were displayed stereoscopically. The presence of fenestration in the proximal segment of the anterior cerebral artery was identified and evaluated retrospectively by MRA.

RESULTSSix patients (four men and two women, 15 to 63 years of age, median age 50 years) had proximal ACA fenestration. The appearance rate of ACA fenestration was 0.8% (6/762). All 6 fenestrations were located at the A1 segment: three of them were with a slit-like shape and three were with a convex-lens-like shape, 5 of the right A1 segment, 1 of the left A1 segment.

CONCLUSIONRecognizing ACA fenestration is important to interpret cranial MR angiographys and helpful to make a plan for neurosurgical procedures or neurological intervention.

Adolescent ; Adult ; Anterior Cerebral Artery ; abnormalities ; Cerebral Angiography ; methods ; Cerebral Arterial Diseases ; diagnosis ; Female ; Humans ; Magnetic Resonance Angiography ; methods ; Male ; Middle Aged ; Young Adult

OBJECTIVETo explore the significance of the trans-longitudinal fissure keyhole approach for distal anterior cerebral artery aneurysms.

METHODSFrom March 2000 to October 2002, the trans-longitudinal fissure keyhole approach was adopted for 11 cases of distal anterior cerebral artery aneurysms, which including 9 cases of A2 segment and 2 cases of A3 segment.

RESULTSAll cases were clipped successfully without any obvious neurological deficit and surgical death. Post-operative digital subtraction argiography demonstrated that all aneurysms disappeared. There was no need for foreign blood transformation. The mean hospitalization was 11 days.

CONCLUSIONSThe keyhole approach is an effective and minimal-invasive approach in treating distal anterior cerebral artery aneurysms. It can also shorten hospitalization, decrease foreign blood transformation rate and reduce medical cost.

Adult ; Angiography, Digital Subtraction ; Anterior Cerebral Artery ; surgery ; Cerebral Angiography ; Female ; Humans ; Intracranial Aneurysm ; diagnostic imaging ; surgery ; Male ; Microsurgery ; methods ; Middle Aged ; Neurosurgical Procedures ; methods

OBJECTIVETo compare the feasibility of bone and calcified plaque subtracted dual-energy CT angiography (CTA) with time of flight magnetic resonance angiography (TOF MRA) in evaluation of internal carotid artery atherosclerosis.

METHODSTotally 32 patients received a dual-energy CTA scan, along with a cerebral TOF MRA scan before or after CTA examination from one day to one month. Dual-energy software was used for bone and calcified plaque subtraction. Five anatomical segments were described for each internal carotid artery according to Fischer (1938). Ratings were based on a 1-4 scale for the dual-energy CTA maximum intensity projection (MIP) image: 1 not diagnostic, 2 partially diagnostic, 3 diagnostic, and 4 excellent. Lesions were categorized as mild (0-29%), moderate (30%-69%), severe (70%-99%), or occluded (no flow detected). Stenosis of internal carotid artery was evaluated based on post-subtracted CTA images and TOF MRA images.

RESULTSIn 320 arterial segments, 99% of arterial segments were > or = 3 score. Grading of stenosis on dual-energy CTA agreed with grading of stenoses on MRA images in 98% of arteries. In the mild and occlusion group, the agreement was 100% respectively. In the moderate and severe group, dual-energy CTA showed more severe stenosis than MRA in 7 vessels and there was significant difference between the results from the two different modalities (Z = -3.071, P = 0.002).

CONCLUSIONDual-energy CTA can be used to assess the stenosis of internal arteries around skull base, but may exaggerate the severe stenosis of cerebral arteries compared with TOF MRA.

Aged ; Angiography, Digital Subtraction ; methods ; Carotid Artery, Internal ; pathology ; Carotid Stenosis ; diagnosis ; Cerebral Angiography ; methods ; Cerebral Arteries ; diagnostic imaging ; pathology ; Female ; Humans ; Intracranial Arteriosclerosis ; diagnosis ; Magnetic Resonance Angiography ; Male ; Middle Aged ; Radiographic Image Enhancement ; methods ; Tomography, X-Ray Computed ; methods

OBJECTIVE: We aimed to introduce our method involving prepuncture ultrasound scan for cannulation of the common femoral artery (CFA) during transfemoral cerebral angiography (TFCA), and to assess the clinical and radiological outcomes. MATERIAL AND METHODS: Our study included 90 patients who underwent prepuncture ultrasound examination of the inguinal area for TFCA between April 2015 and June 2015. Prior to skin preparation and draping of the inguinal area, we identified the CFA and its bifurcation using ultrasound. Based on the ultrasound findings, we marked cruciate lines in the inguinal area. Thereafter, we inserted a puncture needle at the interface between the horizontal and vertical lines at a 30–45° angle, simultaneously palpating the pulsation of the femoral artery. After TFCA was completed, femoral artery angiography was performed in the anteroposterior and oblique directions. Clinical and radiological parameters, including CFA cannulation, the ultrasound scan time, the first pass success rate, the time required for the passage of the wire, and complications, were evaluated. RESULTS: The mean ultrasound scan time of the CFA and its bifurcation was 72.6 seconds, and the mean time between administration of local anesthesia and wire passage was 67.44 seconds. The first pass success rate was 77.8% (70/90 patients), and the CFA puncture rate was 98.8% (89/90 patients). Although minor complications were noted in 7 patients, no patient reported serious complications (a large hematoma [≥ 5 cm], pseudoaneurysms, dissection, and/or a retroperitoneal hematoma.) CONCLUSION: Prepuncture ultrasound examination might be a simple, safe, and accurate technique for cannulation of the CFA during TFCA.
Anesthesia, Local ; Aneurysm, False ; Angiography ; Catheterization ; Cerebral Angiography* ; Femoral Artery* ; Hematoma ; Humans ; Methods ; Needles ; Punctures ; Skin ; Ultrasonography*

OBJECTIVETo investigate the value of virtual imaging technique in diagnosis of intracranial aneurysms.

METHODSFifty-four cases of 54 intracranial aneurysm diagnosed by three-dimensional CT angiography (3D-CTA) examinations were enrolled in this study. Three-dimensional virtual images of the skull and cerebral vessels were acquired by three-dimensional reconstruction of the original CT images using the surgical planning system, and the location, size and shape of the aneurysms and their anatomical relationship with the adjacent tissues were observed and measured from several angles. All the patients underwent surgical planning and simulated surgical operations using the virtual surgical instruments available in the system.

RESULTSAll the 54 cases had successful three-dimensional virtual image reconstruction and the surgical planning operations. The virtual imaging system generated clear and vivid three-dimensional virtual images which clearly visualized the location and size of the aneurysms and their precise anatomical relations to the parent arteries and skull. This virtual reality imaging system also allowed simulation of simple surgical procedures.

CONCLUSIONThe surgical planning system based on the virtual reality imaging can serve as a useful means to assist the diagnosis and provide precise imaging details of intracranial aneurysms.

Cerebral Angiography ; methods ; Humans ; Imaging, Three-Dimensional ; methods ; Intracranial Aneurysm ; diagnostic imaging ; Tomography, X-Ray Computed ; methods

OBJECTIVETo evaluate the safety and efficacy of stent placement for the treatment of complex intracranial aneurysms.

DATA SOURCESWe searched six databases, including Pubmed, Embase, SCI-expanded, the Cochrane Library, ISI Proceedings and ProQuest Dissertations & Theses for the relevant studies using multiple key words from December, 1997 to February, 2009.

STUDY SELECTIONThirty-three studies about stent placement for intracranial aneurysms were identified, which reported data from a total of 1069 patients with 1121 intracranial aneurysms.

DATA EXTRACTIONWe prepared a standardized data extraction form (DEF), which was used by two independent researchers to extract data from the included 33 studies.

RESULTSThe overall initial complete occlusion rate was 52.5% (456/869, 95%CI: 49.2% - 55.8%). The overall complication rate was 14.3% (162/1130, 95%CI: 12.3% - 16.4%), of which 3.6% (38/1044, 95%CI: 2.5% - 4.8%) were permanent. Clinical follow-up showed a dependence rate of 8.4% (39/465, 95%CI: 5.9% - 10.9%). Angiographic follow-up showed an improvement rate of 24.3% (117/481, 95%CI: 20.5% - 28.2%) and a recurrence rate of 12.9% (62/481, 95%CI: 9.9% - 15.9%). Chi-squared tests were performed to compare the following subgroups: self-expandable vs. balloon-expandable stents, unruptured vs. acutely ruptured aneurysms, and with vs. without pre-medication. Statistical significance was reached in eight tests.

CONCLUSIONSIntracranial stent is a safe and effective tool for embolizing complex intracranial aneurysms. Self-expandable stents are significantly easier and safer than balloon-expandable stents with respect to navigation and deployment through the tortuous cerebral vasculature. Patients with acutely ruptured aneurysms are more likely to be dependent, but not more likely to suffer more procedure-related complications.

Cerebral Angiography ; Embolization, Therapeutic ; methods ; Humans ; Intracranial Aneurysm ; diagnostic imaging ; therapy ; Stents ; adverse effects

PURPOSE: The purpose of this study was to examine the effects of bed angles and bed rest time combined with hemostatic methods on discomfort and hemorrhagic complications in patients after transfemoral cerebral angiography. METHODS: Data were collected from 93 inpatients following transfemoral cerebral angiography, from April 20 to September 23, 2016. Patients were grouped according to bed angle (0° vs. 30°) and bed rest time combined with hemostatic methods (4-hour bed rest after manual compression vs. 2-hour bed rest after applying vascular closure device). RESULTS: There was a significant group differences on discomfort (F=46.44, p<.001). The post-hoc analysis showed the lowest score of discomfort in those with bed angle 30o and 2-hour bed rest. There was no difference in hemorrhagic complications among 4 groups. CONCLUSION: The postangiograpy discomfort can be effectively reduced with the least hemorrhagic complications by bed angle 30° elevation and 2-hour bed rest after applying vascular closure device for those underwent transfemoral cerebral angiography.
Bed Rest ; Cerebral Angiography ; Hemorrhage ; Humans ; Inpatients ; Methods ; Vascular Closure Devices

OBJECTIVE: To assess the safety and efficacy of Neuroform Atlas stent used in treatment of unruptured wide-neck intracranial aneurysms. METHODS: Clinical data of 62 patients with unruptured wide-neck intracranial aneurysms undergoing Neuroform Atlas stent-assisted coiling from August 2020 to September 2021 were retrospectively analyzed. There were 64 aneurysms in those 62 patients. Among them, 25 aneurysms were located at the bifurcation of M1 segment on middle cerebral artery, 16 at the anterior communicating artery, 10 at the C7 segment of internal carotid artery, 5 at the C6 segment of internal carotid artery, 4 at the apex of basilar artery, 3 at the A3 segment of anterior cerebral artery, and 1 at the M2 segment of middle cerebral artery. All the patients underwent Neuroform Atlas stent-assisted coiling, including 49 patients with single stent assisted coiling and 15 patients with dual stents assisted coiling (14"Y"style and 1"X"style). After the procedure, the immediate DSA was performed to evaluate the status of aneurysm occlusion and the parent artery patency. The clinical follow-up was performed 3 months after the operation and evaluated based on the modified Rankin Scale(mRS).DSA image was reviewed at 6 months after operation and Raymond grading scale was used to assess the status of aneurysm occlusion and the parent artery patency. RESULTS: A total of 62 patients with 64 aneurysms were all achieved technical success(100%).The immediate post-procedural Raymond scale was assessed, including Raymond Ⅰ in 57 aneurysms(89.1%, 57/64), Raymond Ⅱ in 6 aneurysms(9.3%, 6/64) and Raymond Ⅲ in 1 aneurysm(1.6%, 1/64). The peri-procedural complications rate was 4.8%(3/62), 2 patients developed intraoperative thrombosis and 1 patient suffered from local subarachnoid hemorrhage. Among them, 55 patients obtained 3 months clinical follow-up after operation and all the patients had good outcomes (mRS≤2), 50 patients with 52 aneurysms were followed up with DSA 6 months after operation, including Raymond Ⅰ in 45 aneurysms(86.5%, 45/52), Raymond Ⅱ in 4 aneurysms(7.7%, 4/52) and Raymond Ⅲ in 3 aneurysms(5.8%, 3/52). CONCLUSION Neuroform Atlas stent for the treatment of unruptured wide-neck intracranial aneurysms has high safety and good efficacy, and has its advantages over other traditional stents.
Humans ; Intracranial Aneurysm/etiology* ; Retrospective Studies ; Treatment Outcome ; Embolization, Therapeutic/methods* ; Stents/adverse effects* ; Cerebral Angiography