Prioritized Venous Coiling Facilitating Endovascular Treatment of Brain Arteriovenous Malformations with a Fistulous Component.

BACKGROUND: Brain arteriovenous malformation (AVM) with a fistulous component presents a treatment challenge. The presence of the fistulous component may be related to either a complication from endovascular treatment, perioperative hemorrhagic events during surgical resection, or incomplete obliteration after radiosurgery. CASE DESCRIPTION: From December 2010 to May 2014, 7 consecutive patients (3 men, 4 women, average age, 28.7 years; age range, 11 months to 67 years) with AVMs with a high-flow fistulous component were treated at our institute with venous coiling before transarterial liquid embolization. One AVM was grade I based on the Spetzler-Martin grading system, 1 was grade II, 3 were grade III, and 2 were grade IV. The nidus size ranged from 1.7 to 6.0 cm. Four patients had pure fistulous-type lesions, and 3 had lesions of the mixed fistulous-plexiform type. All AVMs shared a common feature of a high-flow fistulous component with a large venous pouch emerging from the nidus. After endovascular embolization of the AVMs, 3 patients had complete occlusion, 3 patients had near-complete occlusion, and 1 patient had significant reduction in volume. There was no immediate complication after embolization, but 1 patient experienced delayed hemorrhage 3 days after the procedure. CONCLUSIONS: Prioritized transarterial venous coiling is feasible for the embolization of AVMs with a high-flow fistulous component and the procedure had an acceptable complication rate.

Endovascular treatment and computed imaging follow-up of 14 anterior condylar dural arteriovenous fistulas.

We report our experience in treating the anterior condylar dural arteriovenous fistula (DAVF) and confirm the location of the coils in the follow-up images after successful endovascular treatment. We retrospectively reviewed the 14 patients with anterior condylar DAVF treated successfully in our institute. Twelve of them had CT or MR follow-up images. All the patients had intravascular coiling of the fistula. Seven of our patients had retrograde drainage to different sinuses. Three had ocular symptoms as a clinical manifestation. We treated nine patients with coils alone (eight transvenous, one transarterial), four with adjuvant transarterial treatment with particles or liquid embolic for minimal residual after coiling packing. One patient had failed onyx treatment and successful treatment by following transvenous packing. All patients had total obliteration of the DAVF fistula on immediate post-procedure angiogram or on the follow-up images and no evidence of recurrence clinically. The mean follow-up period was 34.2 months (standard deviation=39.8). Twelve patients had computed images (CT alone in four, MR alone in five, both CT and MR in three). These findings were analyzed by four certified neuroradiologists. We found 100% of the coils at the anterior condylar veins inside the hypoglossal canal, 54.2% at the lateral lower clivus, and only 14.2% at the anterior condylar confluence which is ventrolateral to the anterior orifice of the hypoglossal canal. Intravascular coiling is the treatment of choice in patients with anterior condylar DAVF. All the coils were found at the anterior condylar veins inside the hypoglossal canal after successful treatment.

Reactive postural control deficits in patients with posterior parietal cortex lesions after stroke and the influence of auditory cueing.

OBJECTIVE: The purpose of this study was to investigate the ways in which stroke-induced posterior parietal cortex (PPC) lesions affect reactive postural responses and whether providing auditory cues modulates these responses. DESIGN: Seventeen hemiparetic patients after stroke, nine with PPC lesions (PPCLesion) and eight with intact PPCs (PPCSpared), and nine age-matched healthy adults completed a lateral-pull perturbation experiment under noncued and cued conditions. The activation rates of the gluteus medius muscle ipsilateral (GMi) and contralateral to the pull direction, the rates of occurrence of three types of GM activation patterns, and the GMi contraction latency were investigated. RESULTS: In noncued pulls toward the paretic side, of the three groups, the PPCLesion group exhibited the lowest activation rate (56%) of the GMi (P < 0.05), which is the primary postural muscle involved in this task, and the highest rate of occurrence (33%) of the gluteus medius muscle contralateral-activation-only pattern (P < 0.05), which is a compensatory activation pattern. In contrast, in cued pulls toward the paretic side, the PPCLesion group was able to increase the activation rate of the GMi to a level (81%) such that there became no significant differences in activation rate of the GMi among the three groups (P > 0.05). However, there were no significant differences in the GM activation patterns and GMi contraction latency between the noncued and cued conditions for the PPCLesion group (P > 0.05). CONCLUSIONS: The PPCLesion patients had greater deficits in recruiting paretic muscles and were more likely to use the compensatory muscle activation pattern for postural reactions than the PPCSpared patients, suggesting that PPC is part of the neural circuitry involved in reactive postural control in response to lateral perturbations. The auditory cueing used in this study, however, did not significantly modify the muscle activation patterns in the PPCLesion patients. More research is needed to explore the type and structure of cueing that could effectively improve patterns and speed of postural responses in these patients.

A remotely-controlled locomotive IC driven by electrolytic bubbles and wireless powering.

A batteryless remotely-controlled locomotive IC utilizing electrolytic bubbles as propelling force is realized in 0.35 µm CMOS technology. Without any external components, such as magnets and on-board coils, the bare IC is wirelessly powered and controlled by a 10 MHz ASK modulated signal with RS232 control commands to execute movement in four moving directions and with two speeds. The receiving coil and electrolysis electrodes are all integrated on the locomotive chip. The experiment successfully demonstrated that the bare IC moved on the surface of an electrolyte with a speed up to 0.3 mm/s and change moving directions according to the commands. The total power consumptions of the chip are 207.4 µW and 180 µ W while the output electrolysis voltages are 2 V and 1.3 V, respectively.

Rapid, sequential bilateral acute carotid blowout syndrome.

INTRODUCTION: This study aims to report the treatment and outcome of sequential bilateral acute carotid artery blowout syndrome. METHODS: From 2004 to 2010, we treated seven male patients with sequential bilateral blowout syndrome long after irradiation treatment for head and neck cancer. After first common carotid artery (CCA)-internal carotid artery (ICA) rupture, six were treated with CCA-ICA occlusion and one with graft stenting. The contralateral ICAs were normal or stenotic on angiography in all patients. After the contralateral CCA-ICA rupture, five patients received CCA-ICA occlusion, one received graft stent treatment, and one received no treatment. RESULTS: Five of the seven patients died soon after the final treatment. Two patients developed cerebral infarctions (one treated with bilateral stenting, one treated with occlusion), one died from extensive local infection, one died soon after a third treatment, one died of progression of the disease, and one refused a second treatment and died soon after the diagnostic angiography. Two patients survived with follow-up periods of 1 and 5 years. In all seven patients, the contralateral CCA-ICA blowout occurred within 3 months after the first ICA occlusion. CONCLUSION: Bilateral ICA occlusion is an alternative management for sequential carotid artery blowout, but the mortality is high and outcome is poor. A normal angiogram cannot exclude the possibility of rapid development of a contralateral carotid artery blowout shortly after a first episode in patients who have received radiotherapy for head and neck cancer.

Aggressive revascularization of acute internal carotid artery occlusion in patients with NIHSS>20 and poor collateral circulation: preliminary report.

BACKGROUND: Acute occlusion of internal carotid artery (ICA) is a clinical catastrophic entity with mortality as high as 50%. With innovative devices and technology, we want to clarify the benefit and risk of interventional treatment for those patients. METHODS AND RESULTS: From 2005 to 2009, 62 patients were enrolled and 7 patients were diagnosed as total ICA occlusion with severe neurological deficit and poor collateral circulation received endovascular interventions. Intra-arterial thrombolysis was performed in all the 7 patients. Besides, angioplasty was done in 2 patients, stenting in 3, and thrombosuction in 1. The average NIHSS was 23.3 (standard deviation=3.6) before revascularization, was 14.2(standard deviation=6.8) on day 7. Three patients had symptomatically hemorrhagic transformation and one developed severe brain edema after procedure. Decompressive craniotomy has been conducted in 3, who survived thereafter. One patient died for refusal of decompressive craniotomy. The 30-day modified Rankin scale was 1 in 1, 2 in 1, 3 in 1, and 4 in 3. All of our patients had distal residual lesions at anterior or middle cerebral artery area, and delayed recanalization was noted in 4. CONCLUSIONS: Endovascular therapy was promising as a hyperacute management for patients of ICA total occlusion leading to survival rate more than 80% and significant neurological recovery in 50% of our patients. Distal residual lesions were common in patients of total carotid occlusion after aggressive revascularization. Although the mechanism was not clear, delayed re-canalization was common in such patients.

A miniature patient-mount navigation system for assisting needle placement in CT-guided intervention.

BACKGROUND: CT-guided intervention is routinely performed in an iterative fashion that often leads to lengthy operation and high X-ray exposure to patients. To streamline the workflow, we develop a patient-mount navigation system for assisting needle placement in CT-guided interventions. METHODS: The system comprises three components, a miniature patient-mount tracking unit, an auto-registered reference-frame unit and an intuitive image-processing unit. The system is operated like a virtual biplane fluoroscopy with augmented CT reconstructed images to streamline the conventional CT-guided intervention workflow. Surgery efficiency and safety can be increased, while radiation for patients and surgeons can be reduced. Two preclinical validations were conducted to evaluate the technical applicability and accuracy of the system. RESULTS: The results of the rigid physical phantom test showed a machine position error of 1.6 mm and a tilting error of 1.5°. The results of the deformable porcine phantom test showed the operation position error to be 3.6 mm and tilting error to be 2.9°. CONCLUSIONS: We concluded that the accuracy of our system is within the comparable range of the existing navigation systems.

A patient-mount navigated intervention system for spinal diseases and its clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion.

STUDY DESIGN: Development of a patient-mount navigated intervention (PaMNI) system for spinal diseases. An in vivo clinical human trial was conducted to validate this system. OBJECTIVE: To verify the feasibility of the PaMNI system with the clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion (PRF-DRG). SUMMARY OF BACKGROUND DATA: Two major image guiding techniques, i.e., computed tomography (CT)-guided and fluoro-guided, were used for spinal intervention. The CT-guided technique provides high spatial resolution, and is claimed to be more accurate than the fluoro-guided technique. Nevertheless, the CT-guided intervention usually reaches higher radiograph exposure than the fluoro-guided counterpart. Some navigated intervention systems were developed to reduce the radiation of CT-guided intervention. Nevertheless, these systems were not popularly used due to the longer operation time, a new protocol for surgeons, and the availability of such a system. METHODS: The PaMNI system includes 3 components, i.e., a patient-mount miniature tracking unit, an auto-registered reference frame unit, and a user-friendly image processing unit. The PRF-DRG treatment was conducted to find the clinical feasibility of this system. RESULTS: The in vivo clinical trial showed that the accuracy, visual analog scale evaluation after surgery, and radiograph exposure of the PaMNI-guided technique are comparable to the one of conventional fluoro-guided technique, while the operation time is increased by 5 minutes. CONCLUSION: Combining the virtues of fluoroscopy and CT-guided techniques, our navigation system is operated like a virtual fluoroscopy with augmented CT images. This system elevates the performance of CT-guided intervention and reduces surgeons' radiation exposure risk to a minimum, while keeping low radiation dose to patients like its fluoro-guided counterpart. The clinical trial of PRF-DRG treatment showed the clinical feasibility and efficacy of this system.

Role of the premotor cortex in leg selection and anticipatory postural adjustments associated with a rapid stepping task in patients with stroke.

The premotor cortex (PMC) plays an important role in selecting and preparing for movement. This study investigates how stroke-induced PMC lesions affect stepping leg selection and anticipatory postural adjustments (APAs) preparation. Fifteen hemi-paretic patients (eight with PMC lesions (PMC(Lesion)) and seven PMC spared (PMC(Spared))) and eight age- and sex-matched healthy adults participated in the study. The subjects performed rapid forward stepping with the right or left leg under simple and choice reaction time conditions. The percentage of trials in which the subject showed the correct initial vertical ground reaction force pattern before lift-off of the stepping leg indicated the accuracy in selecting the designated stepping leg. The latency of bilateral contractions in the tibialis anterior (TA) and the reaction time (RT) of the stepping leg represented the time needed to prepare for stepping-related APAs and stepping movement, respectively. All three groups demonstrated a similar rate of accuracy of the stepping leg selection under both conditions. However, in both conditions, the PMC(Lesion) group exhibited a longer RT and TA contraction latency of the affected leg than the healthy and PMC(Spared) groups. The PMC(Lesion) group also presented a longer TA contraction latency of the unaffected leg than the healthy group in both conditions. These results suggest that the PMC is involved in APAs associated with leg stepping movement and that a PMC lesion in one hemisphere impairs APAs of both the contralateral and ipsilateral legs during stepping.

Intracranial dural arteriovenous fistulas: diagnosis and evaluation with 64-detector row CT angiography.

PURPOSE: To analyze the diagnostic effectiveness and application of computed tomographic (CT) angiography by using a new algorithm (hybrid CT angiography) in dural arteriovenous fistulas (AVFs). MATERIALS AND METHODS: Institutional review board approval was obtained for retrospectively postprocessing the raw data from CT angiography by using hybrid CT, which is a mixture of a bone subtraction and masking method for bone removal. The study included 22 patients with 24 dural AVFs and 14 control subjects. The grades in patients with dural AVF determined with hybrid CT angiography and digital subtraction angiography (DSA) were compared, and hybrid CT angiography was applied as a tool for planning endovascular treatment. The adjusted Wald method was used to estimate confidence intervals (CIs), and the Cohen kappa statistic was used to assess interobserver agreement. RESULTS: Hybrid CT angiography in the 24 dural AVFs revealed asymmetric sinus enhancement in 22 lesions (92%), engorged arteries in 19 (79%), transosseous enhanced vessels in 19 (79%), engorged extracranial veins in 13 (54%), engorged cortical veins in seven (29%), and sinus thrombosis in four (17%). In all 24 lesions, at least two of six imaging signs for diagnosis of dural AVFs were present. The kappa test analysis revealed a high level of interobserver agreement (kappa, 0.56-1.00) in reading the diagnostic imaging signs. The observed agreement between DSA and readers was 100% in the cavernous sinus region and in hypoglossal and clival lesions and 78%-89% in the transverse sigmoid sinus. The overall sensitivity, specificity, positive predictive value, and negative predictive value were 0.93 (95% CI: 0.85, 0.97), 0.98 (95% CI: 0.93, 1.00), 0.97 (95% CI: 0.90, 0.99), and 0.95 (95% CI: 0.90, 0.98), respectively. CONCLUSION: Hybrid CT angiography is a promising tool for the diagnosis of dural AVF. It can provide key information necessary for treatment planning.

Prophylactic vertebroplasty may reduce the risk of adjacent intact vertebra from fatigue injury: an ex vivo biomechanical study.

STUDY DESIGN: In vitro biomechanical study using human spine specimens. OBJECTIVE: To find the biomechanical consequences of prophylactic vertebroplasty post fatigue loading. SUMMARY OF BACKGROUND DATA: Percutaneous vertebroplasty man be an effective treatment for osteoporotic vertebral compression fracture. One frequently observed complication post surgery is the adjacent vertebral failure (AVF). The prophylactic vertebroplasty was proposed to prevent the AVF. The vertebroplasty is, nevertheless, an invasive intervention. More scientific proves are needed for the application of this surgery on a still intact vertebra. METHODS: Fourteen 5-level fresh human cadaveric thoracic motion segments were divided into standard and prophylactic group. Both ends of the specimen were mounted, leaving the center 3 vertebrae free. The lower level of free vertebrae was artificially injured and cement augmented. The center level vertebra of standard group remained intact and nonaugmented. The center level vertebra of prophylactic group also remained intact, but augmented with bone cement. The specimen was applied with a 2-hour, 5-Hz, 630-N (mean) compressive fatigue loading. Impulse test and CT scanning were conducted both before and after fatigue loading to find the variance of strain compliance of cortical shell and height of vertebral body. RESULTS: The strain compliance of cortical shell is generally not statistically significantly affected by the fatigue loading, cement augmentation and vertebral level (All P > 0.05). The only exception is that the cortical strain compliance of augmented vertebrae tentatively decreased post fatigue loading (P = 0.012 for tensile strain compliance, and P = 0.049 for compressive strain compliance). The height loss of intact vertebra adjacent to a 2-level augmented (or intact-augmented) vertebra is significantly lower than the one adjacent to a 1-level augmented (or injury-augmented) vertebra (P = 0.014). For an osteoporotic vertebra, neither cortical strain compliance nor vertebral height loss is connected with bone mineral density (all P > 0.05). CONCLUSION: The strain compliance of cortical shell is generally not a sensitive indicator to predict risk of fatigue injury if the fatigue loading is mild. The prophylactic augmentation strengthens the osteoporotic vertebrae, decreases the progression of vertebral height loss, reduces the anterior body shift, and hence protects the adjacent intact vertebra from elevated flexion bending. It can be cautiously suggested that if the vertebra is osteoporotic and adjacent level is located at pivot or lordotic level of spinal column, the prophylactic augmentation may be an option to prevent the AVF.

Cervicocranial arterial dissection: experience of 73 patients in a single center.

BACKGROUND: Arterial dissection involving cervicocranial arteries usually results in ischemia or SAH. This study correlated the clinical manifestations, image characteristics, and outcome of arterial dissection and compared the differences between arterial dissection of anterior and posterior circulation at our institute. METHODS: Clinical symptoms and neuroradiologic findings were retrospectively analyzed in 73 patients (6-75 years old) who had a spontaneous arterial dissection of cervicocranial vessels verified by angiography or MRI. Twenty-four cases of ACAD and 49 cases of PCAD were included in this study. RESULTS: The leading presentation of arterial dissection of ACAD group was ischemic stroke (79.2%), and that of posterior circulation was SAH (44.9%), followed by ischemic stroke (42.8%). In the ACAD group, the extracranial ICA was more commonly involved (62.5%), with long segmental narrowing the most common angiographic finding. In the PCAD group, the intracranial VA was more commonly involved (81.6%), with alternating narrowing and dilatation the leading angiographic picture. All the cases presenting with ischemic stroke or headache were conservatively treated with anticoagulants or antiplatelets, except for one treated with intra-arterial thrombolysis for thromboembolism in basilar artery at an early stage. One of them died of progressed brainstem infarct in spite of anticoagulation therapy. All the others reached improved or stable clinical condition. Eighteen cases were treated by surgical or endovascular intervention. None of them had rebleeding. Of the 5 patients with SAH due to dissecting lumens without treatment, 2 died of rebleeding. CONCLUSIONS: Ischemia is the predominant presentation of ACAD; and PCAD has similar occurrence of SAH and ischemia. Intracranial arterial dissection is not uncommon; and it should be kept in the list of differential diagnosis of young stroke. Aggressive treatment of arterial dissection presenting with SAH should be considered; otherwise, rebleeding may occur.

Vertebroplasty using real-time, fluoroscopy-controlled, catheter-assisted, low-viscosity cement injection.

STUDY DESIGN: Case series. OBJECTIVE: Evaluation of new vertebroplasty technique. SUMMARY OF BACKGROUND DATA: Viscous polymethylmethacrylate cement is frequently used to avoid leakage in vertebroplasty. However, the large force required to inject the cement can require the use of special equipment or the direct injection of the cement without a cannula. In addition, injection under fluoroscopic guidance with a short or absent cannula is associated with a higher intraoperative radiation dose. A method using an angiographic catheter for thin cement injection is presented. METHODS: Real-time, fluoroscopy-controlled, catheter-assisted, thin cement injection was used for 102 vertebroplasty sessions (84 patients, 148 vertebrae). Leakage was monitored in 85 procedures via computed tomography. RESULTS: All vertebral bodies were successfully and satisfactorily filled with bone cement. Cement leakage was evident in 50% of the 85 asymptomatic cases (25 paraspinal, 29 epidural, and 30 intradisc space). On follow-up, new compression fractures were noted in the same (n = 5) or adjacent (n = 16) vertebral body, and elsewhere (n = 10). Vertebroplasty provided pain relief in >90% of cases. Recurrent compression fracture occurred in 5 vertebrae of 4 patients after vertebroplasty. New compression fractures occurred in 16 adjacent vertebral bodies of 11 patients and in 10 vertebral bodies remote from the site. One patient who developed osteomyelitis was successfully treated with antibiotics alone. CONCLUSION: Real-time, fluoroscopy-controlled, catheter-assisted, low-viscosity cement injection is a safe and feasible method for vertebroplasty, and produces a comparable outcome as high-viscosity cements.

Simultaneous bilateral carotid stenting in one session in high-risk patients.

The authors report their experience in treating a group of 6 high-risk patients with severe bilateral carotid disease by carotid artery stenting in a single session. The patients were men aged 53 to 83 years. All had bilateral, synchronous, symptomatic ischemic disease. Five of the 6 patients had severe bilateral carotid stenoses due to atherosclerotic disease: the sixth had a dissecting aneurysm on one side. All were treated with self-expandable stents: a distal protection device was used. All stenting procedures were technically successful. Stenoses averaged 84 +/- 8% before the procedure and 10 +/- 7% after. No procedure-related complications occurred and no 30-day postoperative complications were found. One patient experienced bradhycardia and hypotension for 1 day and was treated medically. After careful preparation and perioperative procedures in a selected group of patients, simultaneous bilateral carotid stenting procedures are feasible when required and appear to be relatively safe.

The leakage pathway and effect of needle gauge on degree of disc injury post anular puncture: a comparative study using aged human and adolescent porcine discs.

STUDY DESIGN: An in vitro biomechanical study using aged human and adolescent porcine discs. OBJECTIVES: To find the leakage pathway and effect of needle gauge on the degree of disc injury post anular puncture. SUMMARY OF BACKGROUND DATA: Spinal needles are widely used for minimal invasive disc surgeries and disc degeneration/regeneration research. Applications of anular puncture require different diameters of spinal needles. However, the effect of needle diameters on the disc injury has not been systematically studied yet. METHODS: Four groups of experiments were conducted: 1) porcine thoracic disc, 2) human thoracic disc, 3) porcine thoracic disc with 200 N external loading, and 4) porcine lumbar discs. The disc was punctured consecutively with needles from smaller diameter to larger diameter. After each anular puncture, the quantitative discomanometry technique was conducted to quantify the disc rupture pressure and volume. The association between needle gauge and rupture pressure and volume was analyzed. RESULTS: The degree of disc injury increased with the diameter of needle. For an aged human thoracic disc, the anulus fibrosus cannot hold pressure more than 2 MPa after a 21-gauge-needle-anular-puncture. The leakage pathway of injected saline was through the anular fissure but was through the endplate when the disc was next to an osteoporotic vertebrae. The pressure holding power of porcine disc is stronger than of human disc. The rupture pressure of porcine lumbar disc is higher than of porcine thoracic disc. The axial compressive external loading increased the disc rupture pressure. The rupture volumes were not affected by the dimension of injury fissure. The rupture volume was at level of 0.3 mL without external loading and at 0.2 mL with external loading. CONCLUSION: A spinal needle of < or = 22 gauge and injection volume of < or = 0.2 mL are recommended to prevent postsurgery leakage.

The implantation of non-cell-based materials to prevent the recurrent disc herniation: an in vivo porcine model using quantitative discomanometry examination.

Recurrent disc herniation is frequently observed due to leakage of nucleus pulposus through injured anulus fibrosus. There is no effective treatment to prevent recurrent disc herniation yet. In this study, we proposed to implant non-cell-based materials into the porcine disc to stimulate the growth of fibrous tissue and thereby increase the disc functional integrity. The disc herniation was simulated by anular punctures using the spinal needles. Four clinically used implantation materials, i.e., gelfoam, platinum coil, bone cement and tissue glue, were delivered into the discs via percutaneous spinal needles. Two months after the surgery, the swine were killed. The degree of disc integrity of intact, naturally healed and implanted discs, was examined by quantitative discomanometry apparatus. We found the disc injury could not recover after 2 months of healing, and the disc implantation affected the degree of disc integrity. The disc integrity of gelfoam-implanted discs was better than that of coil-, bone cement-, and glue-implanted discs. The implantation of non-cell-based material was proved to be a potentially clinically applicable method to recover the integrity of injured discs and to prevent recurrent disc herniation.

Dissociated roles of the middle frontal gyri in the processing of Chinese characters.

The present study examined a hypothesis that the right middle frontal gyrus participates in processing orthography of Chinese characters, while the left middle frontal gyrus mediates access to phonology and semantics. Brain activation during three character tasks, which required processing orthography, phonology, or semantics of Chinese characters, respectively, was measured by functional magnetic resonance imaging. Comparable neural activity in the right middle frontal gyrus was observed in all three character tasks that always demand orthographical processing. In contrast, the left middle frontal gyrus showed greater activation in the phonological and semantic tasks than in the orthographic task. These results suggest that the right and left middle frontal gyrus have dissociable functions in achieving Chinese character recognition.

Aneurysms in twig-like middle cerebral artery.

BACKGROUND: We report a vascular abnormality of the middle cerebral artery (MCA) that has not been described in the literature before. METHODS: Two patients (1 male and 1 female; age 44 and 67 years, respectively) were found to have a vascular abnormality in which the main trunk of the MCA had a twig-like form. Both patients presented with intracranial hemorrhage. RESULTS: In these 2 patients, the abnormality was seen before the genu of the MCA. They had an intracranial hemorrhage due to an associated aneurysm inside the twigs. The twig appeared to be a network between the bifurcation of internal carotid artery and insular segment of MCA, and it was different from the collateral circulation due to acquired occlusion or moyamoya disease. CONCLUSION: This new type of vascular lesion of the MCA is not benign. It appears to be associated with the occurrence of an aneurysm, an important clinical aspect.

Cerebral diffusion tensor images in children with tuberous sclerosis: a preliminary report.

BACKGROUND: In tuberous sclerosis (TS), tubers usually involve the white matter. Diffusion tensor (DT) images are used to demonstrate white-matter tracts. OBJECTIVE: To determine the changes in DT indices in supratentorial tubers and associated changes in the white-matter tracts adjacent to tubers in patients with TS. MATERIALS AND METHODS: The DT imaging indices, including first, second and third eigenvalues (EVs), apparent diffusion coefficients (ADCs), and fractional anisotropy (FA) in the white-matter lesions of tubers, were assessed in seven patients with TS exhibiting developmental delay and compared with controls. RESULTS: EV1, EV2, EV3, ADC and FA of the white-matter lesions of tubers were significantly different from contralateral unremarkable regions of the brain and from controls (P<0.05). The number of frontal and parietal tubers was significantly negatively correlated with EV1 of the superior longitudinal fasciculi of TS patients (r=-0.60, P =0.04). In addition, TS patients had significantly larger ADCs in the corona radiata and sagittal stratum than the control subjects. EV3s of the inferior longitudinal fasciculus and sagittal stratum were significantly more increased in the TS patients than in the control subjects. CONCLUSIONS: EV1, EV2, EV3, ADC and FA maps are potential tools for demonstrating cerebral white-matter changes owing to TS.

18-fluoro-2-deoxyglucose positron emission tomography in detecting residual/recurrent nasopharyngeal carcinomas and comparison with magnetic resonance imaging.

BACKGROUND: It is known that 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is effective in the early detection of residual/recurrent nasopharyngeal carcinomas (NPC). To compare FDG-PET with the conventional magnetic resonance imaging (MRI) for the detection of residual/recurrent NPC, the authors studied 67 follow-up cases of patients with NPC using both FDG-PET and MRI. METHODS: From February 1997 to February 2001, 67 NPC patients (14 women, 53 men; age range, 16-67 years; mean age, 46.6 +/- 12.5 years) were recruited. Both FDG-PET and MRI of the head and neck area for each patient were performed at least 4 months (duration range, 4-70 months; mean, 14 +/- 13.5 months) after radiotherapy or radiotherapy with concurrent chemotherapy. The final diagnosis was confirmed by biopsy or clinical follow-up for at least 6 months. RESULTS: The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of FDG-PET images were 100%, 93.4%, 95.5%, 87.5%, and 100%, respectively. In contrast, the sensitivity, specificity, accuracy, PPV, and NPV of the MRI scans were 61.9%, 43.5%, 49.3%, 33.3%, and 70.0%, respectively. CONCLUSIONS: The results of the current study suggest that FDG-PET is much more effective than MRI in detecting residual/recurrent NPC.