Spasm induced by protection balloon during carotid artery stenting

Purpose The PercuSurge system is a distal balloon embolic protection device used for carotid artery stenting (CAS). We performed a retrospective study on the prognosis and clinical effects of spasms induced by the PercuSurge GuardWire system (PercuSurge-induced spasm). Materials and methods We performed CAS in 118 carotid stenoses using the PercuSurge system. Of the 118 procedures, 31 (26.3%) of the patients experienced PercuSurge-induced spasm, and all underwent postoperative follow-up studies by cerebral angiography and antiplatelet treatment. Results On follow-up angiograms obtained a mean of 5.2 months (range 3–10 months) after CAS, all 31 PercuSurge-induced spasms had disappeared, and no delayed stenosis was found at the sites where the spasms had occurred. No ischemic events due to the spasms occurred during a mean follow-up of 13 months (range 3–32 months). Conclusion In the hands of physicians experienced in endovascular surgery, CAS using the PercuSurge system is a safe method with which to treat patients with carotid stenosis. Our study demonstrated that PercuSurge-induced spasms had no morphological or clinical adverse effects.     

虚拟支架技术在颈动脉狭窄血管内支架成形术中的应用

目的:探讨虚拟支架技术在颈动脉狭窄血管内支架成形术中的应用价值。方法:选取符合颈动脉狭窄支架介入治疗标准的患者45例,通过颈部血管B超、MRA、血管造影和三维重建等方法,确定颈动脉狭窄的程度和部位。运用虚拟支架血管分析程序,得到颈动脉狭窄虚拟支架数据参数。结果:三维重建图像能够立体多角度直观清晰地观察和显示颈动脉狭窄的部位、形态、狭窄程度以及硬化斑块的位置、形态、大小。以虚拟支架技术测量的数据参数为依据,选择相应型号的支架治疗满意率达100%。结论:虚拟支架技术有助于术者在颈动脉狭窄支架成形术中正确地选择合适类型的支架。     

Thalamic hemorrhage following carotid angioplasty and stenting

Carotid angioplasty and stenting (CAS) has emerged as an alternative treatment of carotid stenosis for patients poorly suited for endarterectomy. Intracerebral hemorrhage following carotid revascularization is rare and thought to be related to hyperperfusion injury in most cases. Early experience suggests an increased incidence of hemorrhage following CAS as compared to endarterectomy. We describe a patient who suffered a thalamic hemorrhage following CAS. Because this hemorrhage occurred in a vascular territory unlikely to have been supplied by the treated artery, this case suggests that the mechanism of intracerebral hemorrhage following CAS may in some cases be different from the hyperperfusion hemorrhage classically described following endarterectomy.     

Evaluation of carotid stenosis with axial high-resolution black-blood MR imaging

High-resolution axial black-blood MR imaging (BB MRI) has been shown to be able to characterise carotid plaque morphology. The aim of this study was to explore the accuracy of this technique in quantifying the severity of carotid stenosis. A prospective study of 54 patients with symptomatic carotid disease was conducted, comparing BB MRI to the gold standard, conventional digital subtraction X-ray angiography (DSA). The BB MRI sequence was a fast-spin echo acquisition (TE=42 ms, ETL=24, field of view = 100×100 mm, slice thickness = 3.0 mm) at 1.5 T using a custom-built phased-array coil. Linear measurements of luminal and outer carotid wall diameter were made directly from the axial BB MRI slices by three independent blinded readers and stenosis was calculated according to European Carotid Surgery Trial (ECST) criteria. There was good agreement between BB MRI and DSA (intraclass correlation = 0.83). Inter-observer agreement was good (average kappa = 0.77). BB MRI was accurate for detection of severe stenosis (80%) with sensitivity and specificity of 87 and 81%, respectively. Eight cases of DSA-defined moderate stenosis were overestimated as severe by BB MRI and this may be related to non-circular lumens. Axial imaging with BB MRI could potentially be used to provide useful information about severity of carotid stenosis.     

Diffusion-weighted magnetic resonance imaging of pancreas tumours

The purpose of this study was to evaluate the accuracy of diffusion-weighted imaging (DWI) in diagnosis of pancreas cancer, to compare DWI with a conventional comprehensive MRI (MRI-c) and to analyse apparent diffusion coefficient (ADC) values of lesions. Thirty-six patients with pancreatic lesions (12 malignant and 24 benign) and 39 patients without lesions were included. MRI-c and DWI (free breathing, b values 0 and 500 s/mm²) were performed prospectively and consecutively in a 1.5-T system. The analysis was retrospectively performed blinded by two radiologists in consensus. The sensitivity, specificity, accuracy, and positive and negative predictive values of DWI and MRI-c were 92, 97, 96, 85, 98% and 100, 97, 97, 86, 100%, respectively. Mean ADC values of malignant lesions were significantly lower than those of benign lesions. DWI has a similar accuracy to MRI-c in diagnosis of pancreas cancer.     

颈动脉狭窄致脑低灌注损伤多模态MRI

目的：探讨颈动脉狭窄程度与颈内动脉血流动力学参数及相关脑区ADC值变化的关系。方法：27例患者经磁共振血管成像（MRA）证实有中度以上颈动脉狭窄。所有患者行颅脑常规 MRI、MRA和DWI检查,并采用血流定量测量（QFlow）和彩色多普勒超声（CDFI）对颈内动脉的血流动力学参数进行分析。对 QFlow技术与CDFI 测量的血流参数（血流量、平均流速、峰值流速及管腔面积）及其与颈动脉狭窄程度及相关脑区的表观扩散系数值（ADC ）之间的相关性行非参数检验。结果：①QFlow技术与CDFI测量的血流量和平均流速呈中度正相关（r＝0．695,P＜0．01;r＝0．795,P＜0．01）,峰值流速和管腔面积呈低度正相关（r＝0．453,P＜0．01;r＝0．573,P＜0．01）。②颈动脉狭窄程度与 QFlow 技术测量的颈内动脉流量呈低度负相关（r＝－0．467,P＜0．01）,与侧脑室旁前部和额叶白质的 ADC 值呈低度正相关（r＝0．373,P＜0．01;r＝0．372,P＜0．01）。③侧脑室旁前部和额叶白质的ADC 值与 QFlow 技术测量的颈内动脉流量分别呈中度和低度负相关（r＝－0．624,P＜0．01;r＝－0．533,P＜0．01）。结论：多模态 MRI能显示颈动脉狭窄所致的颈内动脉血流量减低及供血脑区的低灌注损伤,QFlow技术能较准确评价颈内动脉血流动力学变化。     

Magnetic resonance imaging of the normal carotid bifurcation

Summary A Siemens 0.5 Tesla Magnetic Resonance Imaging (MRI) system was used with the saddle head coil and transverse scout localization for imaging 10 normal cervical carotid artery bifurcations in the sagittal plane. Good to excellent visualization of the flow voids and vessel contours was accomplished in all cases. Careful technique and patient cooperation are required.This material was presented at the International Congress of Radiology Honolulu, Hawaii, July 8–12, 1985     

Evaluation of inflammatory status of atherosclerotic carotid plaque before thromboendarterectomy using delayed contrast-enhanced subtracted images after magnetic resonance angiography

Objective

To investigate the correlation among carotid plaque contrast enhancement (CPCE) at MRI, inflammatory cell infiltration (ICI) at histopathology, and carotid stenosis degree.

Materials and methods

Twenty-eight patients (19 males; mean age 67 ± 9 years) scheduled for thromboendarterectomy prospectively underwent 1.5-T MR imaging using: (a) axial T1-weighted gradient-echo (T1wGRE) sequence centered on carotid bifurcations; (b) contrast-enhanced MR angiography (CE-MRA) with 0.1 mmol/kg of gadobenate dimeglumine; (c) enhanced axial T1wGRE sequence as in (a), 3 min after contrast injection. A three-point score system (absent, focal, wide) was used to assess CPCE on native and subtracted MRI images (c minus a) and ICI at histopathology. Carotid stenosis degree was determined on CE-MRA.

Results

Six CPCE studies were discarded due to patient movement. In the remaining 22 studies, CPCE was absent, focal and wide in 13, 6 and 3 cases, respectively; ICI was absent, focal and wide in 13, 7 and 2 cases, respectively (k = 0.57). On CE-MRA 21/28 stenoses were severe and 7/28 moderate. There was no correlation either with ICI (p = 1.000, n = 28) or CPCE (p = 0.747, n = 22).

Conclusion

The correlation between CPCE and ICI suggests a role for CPCE as an independent marker of plaque inflammation.     

Magnetic resonance imaging of carotid artery abnormalities in patients with sphenoid sinusitis

Sphenoid sinusitis is unusual in children, but when it occurs, it can lead to serious intracranial complications. We show the value of MRI in demonstrating intracranial abnormalities due to sphenoid sinus infection, particularly those involving the internal carotid arteries and cavernous sinuses. We reviewed our imaging experience of sphenoid sinusitis and found four patients with ICA narrowing who had undergone MR evaluation including conventional and diffusion imaging. MR angiography was also performed in three patients to determine the extent of ICA narrowing. Narrowing of ICA was found in the cavernous segment in all patients and in the supraclinoid segment in three. Cerebral infarction was found in two patients. In one patient the cavernous sinus showed hyperintensity on diffusion-weighted images and hypointensity on apparent diffusion coefficient map, suggesting reduced diffusion. Although infrequent in children, sphenoid sinus infection should be considered as a possible cause of intracranial infection, particularly in teenagers. Early recognition of cavernous sinus involvement and ICA narrowing may lead to prompt treatment and hence a more favorable outcome.     

Lesion load in unprotected carotid artery stenting

Introduction  The purpose of the study was to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after unprotected carotid artery stent placement. Materials and methods  We retrospectively reviewed a nonrandomized cohort of 197 patients presenting with carotid occlusive disease who underwent unprotected carotid artery stent placement between 2003 and 2006. Mean degree of stenosis was 86.94% ± 9.72. In all patients, DWI was obtained before and 24 h after stent placement. New lesions were evaluated according to size and location. Results  In 59 of 197 patients (29.9%), new ischemic lesions were found on DWI in the vessel dependent area. In 23 of 197 patients (11.7%), new ischemic lesions were found in the vessel independent area. Combined stroke/death rate was 3.63%. Conclusion  In our series of unprotected carotid angioplasty with stent, we found new DWI lesions in 34% of the patients. Further studies should now show in how far protection devices can reduce these lesions. I. Q. Grunwald and P. Papanagiotou contributed equally to this work.     

Diffusion-weighted MR imaging in carotid angioplasty and stenting with protection by the reversed carotid arterial flow

BACKGROUND AND PURPOSE: Distal embolism during carotid angioplasty with stent (CAS) can be protected by a flow-reversal device. Diffusion-weighted MR imaging was used to evaluate this protective procedure and perform a comparison with the control. METHODS: Cases of CAS with protection procedures were included in this study. Sixty-five men (68 procedures) and 5 women (5 procedures), with an average age of 68.8 years, having severe carotid stenosis were treated in our department between 2002 and 2004. Eleven cases were treated with the Parodi Anti-Emboli System, with which the internal carotid blood flow is reversed by simultaneous occlusion of the proximal common carotid artery and external carotid artery. Diffusion-weighted MR imaging was performed within 1-3 days after CAS. As controls, data from diffusion-weighted MR imaging in 26 patients who had diagnostic angiography were included. RESULTS: Diffusion-weighted MR imaging in diagnostic angiography showed 11.5% appearance of ischemic spots after procedures. In the Parodi Anti-Emboli System, this value was 18.2%. In the CAS group, ischemic lesions appeared only in the hemisphere ipsilateral to carotid stenosis. There were no ischemic lesions in the opposite carotid or vertebrobasilar territory. The appearance rate of new ischemic spots was not significantly different between the control group and the group of CAS with Parodi Anti-Emboli System (chi2 test, P = .6227, Fisher exact method). CONCLUSIONS: Protection results obtained with the Parodi system were excellent and comparable with conventional angiography.     

Diffusion-weighted magnetic resonance imaging of head and neck squamous cell carcinomas

Objective

To evaluate whether diffusion-weighted imaging (DWI) is a reliable technique to quantify microstructural differences between head and neck squamous cell carcinomas (SCC) and tumour-free soft tissue.

Materials and methods

DWI was obtained from 20 patients with histologically proven, untreated head and neck SCC. DWI was acquired using a diffusion-weighted, navigated echo-planar imaging sequence with a maximum b-value of 800 s/mm². For an objective assessment of image quality, the signal-to-noise ratio (SNR) was calculated. Microstructural differences between vital tumour tissue and tumour-free soft tissue were quantified by calculating the apparent-diffusion-coefficients (ADC) on a pixel by pixel method.

Results

Echo-planar DWI provided good image quality in all patients (mean SNR 18.4). The mean ADC of SCC, (0.64 ± 0.28 × 10⁻³ mm²/s), was significantly (P < 0.0001) lower than that of the tumour-free soft tissue, (2.51 ± 0.82 × 10⁻³ mm²/s).

Conclusion

DWI is a reliable diagnostic tool to quantify the microstructural differences between vital tumour tissue and tumour-free soft tissue in patients with head and neck SCC.     

Association of carotid atherosclerotic plaque features with acute ischemic stroke: A magnetic resonance imaging study

Background and purpose

It remains unclear whether direct vessel wall imaging can identify carotid high-risk lesions in symptomatic subjects and whether carotid plaque characteristics are more effective indicators for cerebral infarct severity than stenosis. This study sought to determine the associations of carotid plaque characteristics by MR imaging with stenosis and acute cerebral infarct (ACI) sizes on diffusion weighted imaging (DWI).

Materials and methods

One hundred and fourteen symptomatic patients underwent carotid and brain MRI. ACI volume was determined from symptomatic internal carotid artery territory on DWI images. Ipsilateral carotid plaque morphological and compositional characteristics, and stenosis were also determined. The relationships between carotid plaque characteristics, stenosis and ACIs size were then evaluated.

Results

In carotid arteries with 30–49% stenosis, 86.7% and 26.7% were found to have lipid-rich necrotic core (LRNC) and intraplaque hemorrhage, respectively. Furthermore, 45.8% of carotid arteries with 0–29% stenosis developed LRNCs. Carotid morphological measurements, such as % wall volume, and the LRNC size were significantly associated with ipsilateral ACIs volume before and after adjustment for significant demographic factors (age and LDL) or stenosis in patients with carotid plaque (all p < 0.05).

Conclusions

A substantial number of high-risk plaques characterized by vessel wall imaging exist in carotid arteries with lower grade stenosis. In addition, carotid plaque characteristics, particularly the % wall volume and LRNC size, are independently associated with cerebral infarction as measured by DWI lesions. Our findings indicate that characterizing atherosclerotic plaque by MR vessel wall imaging might be useful for stratification of plaque risk and infarction severity.     

Diffusion-weighted magnetic resonance imaging in autoimmune pancreatitis

Purpose  The aim of this study was to investigate the usefulness of diffusion-weighted magnetic resonance imaging (DWI MRI) for the diagnosis and evaluation of autoimmune pancreatitis (AIP). Materials and methods  A total of 4 consecutive patients with AIP, 5 patients with chronic alcoholic pancreatitis (CP), and 13 patients without pancreatic disease (controls) were studied. DWI was performed in the axial plane with spin-echo echo-planar imaging single-shot sequence. Apparent diffusion coefficients (ADCs) were measured in circular regions of interest in the pancreas. In AIP patients, abdominal MRI was performed before, and 2–4 weeks after steroid treatment. Follow-up study was performed chronologically for up to 11 months in two patients. The correlation between ADCs of the pancreas and the immunoglobulin G4 (IgG4) index (serum IgG4 value/serum IgG4 value before steroid treatment) was evaluated. Results  In the AIP patients, DWI of the pancreas showed high signal intensity, and the ADCs of the pancreas (mean ± SD: 0.97 ± 0.18 × 10⁻³ mm²/s) were significantly lower than those in patients with CP (1.45 ± 0.10 × 10⁻³ mm²/s) or the controls (1.45 ± 0.16 × 10⁻³ mm²/s) (Mann-Whitney U-test, P < 0.05). In one AIP patient with focal swelling of the pancreas head that appeared to be a mass, DWI showed high signal intensity throughout the pancreas, indicating diffuse involvement. The ADCs of the pancreas and IgG4 index were significantly inversely correlated (Spearman’s rank correlation coefficient, r _s = −0.80, P < 0.05). Conclusion  Autoimmune pancreatitis showed high signal intensity on DWI, which improved after steroid treatment. ADCs reflected disease activity. Thus, diffusion-weighted MRI might be useful for diagnosing AIP, determining the affected area, and evaluating the effect of treatment. T. Taniguchi and H. Kobayashi contributed equally to this study     

Conventional digital subtraction x-ray angiography versus magnetic resonance angiography in the evaluation of carotid disease: patient satisfaction and preferences

AIM: To compare conventional digital subtraction x-ray angiography (DSA) and contrast-enhanced magnetic resonance angiography (MRA) of the carotid arteries in terms of patient satisfaction and preferences. METHODS: One hundred and sixty-seven patients with symptomatic carotid artery disease, who underwent both DSA and MRA, were prospectively recruited in this study. Patients' perceptions of each method were assessed by the use of a questionnaire after each procedure. Main outcome measures were anxiety, pain, satisfaction rate and patient preferences. RESULTS: DSA generated more anxiety and pain during the procedure, but the severity of these ill-effects was mild. Satisfaction rates for each method were similar. More patients were, however, willing to have a repeat MRA compared with DSA (67 versus 41%). The majority of patients (62%) preferred MRA over DSA (31%). The shorter MRA imaging time was found to be a significant factor in patients' acceptance of the technique. The main reasons cited by patients for their dislike of a particular procedure was noise and claustrophobia for MRA and invasiveness, pain and post-procedural bed rest for DSA. CONCLUSIONS: MRA is the method that is preferred by the majority of patients, although the actual disutility of DSA may be small. Assuming equal diagnostic accuracy, our data supports replacement of DSA by MRA for routine carotid imaging.     

颈动脉狭窄的支架治疗

目的:分析探讨颈动脉支架成形术治疗颈动脉狭窄的安全性。方法:本组34例患者,在球囊扩张及支架释放过程中,全部使用保护伞,并对颈动脉狭窄程度大于70%的16例患者进行预扩张,扩张后根据狭窄长度置入自膨式支架,未扩张的18例患者直接置入自膨式支架,其中有3例未扩张的患者,支架释放后未完全膨胀,但狭窄的直径超过了80%,血流通畅,未进行后扩张。结果:支架置入成功率100%,无1例患者出现脑出血、脑梗塞等严重并发症,支架置入后,支架膨胀良好,血流通畅,患者临床症状得到明显改善。结论:颈动脉支架置入治疗颈动脉狭窄是一种新的治疗方法,亦能代替经典颈动脉内膜剥离术,并对颈动脉狭窄引起的卒中的预防和治疗发挥了重要作用。     

Diffusion-weighted magnetic resonance imaging for demonstration of cerebral infarcts

Summary Forty-one patients demonstrating clinical symptoms for cerebral infarction were investigated by magnetic resonance imaging with diffusion-weighted echo-planar imaging (DWI) and T2-weighted imaging (T2WI). In 8 patients only DWI showed the cerebral lesions clearly. One patient with positive DWI and T2WI suffered from HSV encephalitis. DWI is superior to T2WI in assessment of small cortical infarcts and cerebral infarction in patients with preexisting vascular lesions. DWI is not specific, so other causes like cerebral hematoma and encephalitis have to be considered.      

How should we estimate carotid stenosis using magnetic resonance angiography?

Our purpose was to assess the reproducibility of and differences between the most commonly used methods for assessing carotid artery stenosis using magnetic resonance angiography (MRA). We studied 55 patients who underwent axial three-dimensional time-of-flight MRA (1.5 T). Quantitative caliper measurements were performed from maximum intensity projection (MIP) and multiple planar reconstruction (MPR) images, according to the criteria of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST). The measurements were compared to each other and to visual interpretation, using conventional angiography as the reference. The measured percentage stenoses were higher on MRA than on digital subtraction angiography (DSA) using both NASCET (mean difference 1.9–3.0%) and ECST (6.3–6.7%) criteria. The kappa coefficients for the agreement between DSA and MRA were higher using the NAS-CET (0.61–0.76) than the ECST criteria (0.52–0.65). No statistically significant differences were found between measurements from MIP and MPR images. The ECST measurement criteria gave significantly higher percentage stenoses than the NASCET criteria (P<0.001), this difference being more prominent on MRA (mean difference in diameter stenosis percentage 14.3–16.4%) than on DSA (7.6–11.2%) and most important with mild stenoses. The difference between visual interpretation and quantitative measurements on MRA was significant (P=0.01–0.001). There were no statistically significant interobserver differences in the MRA film readings, either in visually estimated degrees of stenosis or stenosis measurements. Thus, the different criteria of the two multicentre trials led to significantly different results, especially in the assessment of mild stenosis, and these differences are more important with MRA than with aging modalities or the reconstruction programs seem less important.     

颈动脉支架治疗颈动脉狭窄的并发症

目的 探讨颈内动脉狭窄血管内支架治疗的并发症.方法 对648例颈内动脉狭窄患者行全脑血管造影及颈部超声检查.365例患者使用脑保护装置,283例未使用保护装置283例.结果 648例患者技术成功率为100%,患者症状消失或好转率为78.7%.心率＜50次/min者占26.4%;术中栓子脱落5例,其中3例治疗后恢复,2例遗留一侧肢体运动障碍,术后颅内出血死亡3例,术后30 d内总脑卒中或死亡6例,占1.2%.随访率为77 8%.再狭窄17例,占3.3%.结论 颈内动脉狭窄的血管内支架治疗是安全的,但术前对临床及影像学检查正确评价,术中规范化操作及术后规范化护理,是减少并发症的关键.     

Reversal of a 30-h fixed deficit with carotid angioplasty and stenting: technical note

We describe the case of an 82-year-old man with a fixed neurological deficit of 30 h duration. A left hemispheric perfusion deficit was found on perfusion/diffusion imaging studies in conjunction with an ipsilateral carotid stenosis documented by cerebral angiography. Carotid angioplasty with stent placement was performed and resulted in dramatic clinical improvement. Carotid stenosis can cause acute hemodynamic hypoperfusion with a symptomatic reversible clinical deficit.