Differentiating intraparenchymal hemorrhage from contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients undergoing endovascular treatment

Introduction

This study aimed to identify the imaging characteristics that can help differentiate intraparenchymal hemorrhage from benign contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients after endovascular treatment.

Methods

We reviewed the clinical and imaging records of all acute ischemic stroke patients who underwent endovascular treatment in two hospitals over a 3.5-year period. The immediate post-procedural CT scan was evaluated for the presence of hyperdense lesion(s). The average attenuation of the lesion(s) was measured. Intraparenchymal hemorrhage was defined as a persistent hyperdensity visualized on follow-up CT scan, 24 h or greater after the procedure.

Results

Of the 135 patients studied, 74 (55 %) patients had hyperdense lesion(s) on immediate post-procedural CT scan. Follow-up scans confirmed the diagnosis of intraparenchymal hemorrhage in 20 of these 74 patients. A receiver operating characteristic analysis showed that the average attenuation of the most hyperdense lesion can differentiate intraparenchymal hemorrhage from contrast extravasation with an area under the curve of 0.78 (p?=?0.001). An average attenuation of <50 Hounsfield units (HU) in the most visually hyperattenuating hyperdense lesion had 100 % specificity and 56 % sensitivity for identification of contrast extravasations. Petechial hyperdensity was seen in 46/54 (85 %) patients with contrast extravasation versus 9/20 (45 %) patients with intraparenchymal hemorrhage on the immediate post-procedural CT scan (p?Conclusion An average attenuation <50 HU of the most hyperattenuating hyperdense parenchymal lesion on immediate post-procedural CT scan was very specific for differentiating contrast extravasation from intraparenchymal hemorrhage in acute ischemic stroke patients after endovascular treatment.     

The role of dual energy CT in differentiating between brain haemorrhage and contrast medium after mechanical revascularisation in acute ischaemic stroke

Objectives

To assess the feasibility of dual energy computed tomography (DE-CT) in intra-arterially treated acute ischaemic stroke patients to discriminate between contrast extravasation and intracerebral haemorrhage.

Methods

Thirty consecutive acute ischaemic stroke patients following intra-arterial treatment were examined with DE-CT. Simultaneous imaging at 80 kV and 140 kV was employed with calculation of mixed images. Virtual unenhanced non-contrast (VNC) images and iodine overlay maps (IOM) were calculated using a dedicated brain haemorrhage algorithm. Mixed images alone, as “conventional CT”, and DE-CT interpretations were evaluated and compared with follow-up CT.

Results

Eight patients were excluded owing to a lack of follow-up or loss of data. Mixed images showed intracerebral hyperdense areas in 19/22 patients. Both haemorrhage and residual contrast material were present in 1/22. IOM suggested contrast extravasation in 18/22 patients; in 16/18 patients this was confirmed at follow-up. The positive predictive value (PPV) of mixed imaging alone was 25 %, with a negative predictive value (NPV) of 91 % and accuracy of 63 %. The PPV for detection of haemorrhage with DE-CT was 100 %, with an NPV of 89 % and accuracy improved to 89 %.

Conclusions

Dual energy computed tomography improves accuracy and diagnostic confidence in early differentiation between intracranial haemorrhage and contrast medium extravasation in acute stroke patients following intra-arterial revascularisation.

Key Points

? Contrast material and haemorrhage have similar density on conventional 120-kV CT. ? Contrast material hinders interpretation of CT in stroke patients after recanalisation. ? Iodine and haemorrhage have different attenuation at lower kVs. ? Dual energy CT improves accuracy in early differentiation of haemorrhage and contrast extravasation. ? Early differentiation between iodine and haemorrhage helps to initiate therapy promptly.     

Periprocedural aspects in mechanical recanalization for acute stroke: data from the ENDOSTROKE registry

Introduction

The ENDOSTROKE registry aims to accompany the spreading use of endovascular stroke treatment (EVT) in academic and non-academic hospitals. This analysis focuses on preprocedural imaging, patient handling and referral, as well as on different treatment modalities in mechanical recanalization.

Methods

Data for this study were from observational registry study in 12 stroke centers in Germany and Austria with online assessment of prespecified variables concerning endovascular stroke therapy.

Results

Data from 734 patients undergoing EVT were analyzed. Preferred imaging modality prior to EVT was CT (83 %) and CTA (78 %). In 95 %, EVT was performed under general anesthesia. In 55 % of patients, a combination of intravenous (IV) thrombolysis and EVT was used, followed by pure EVT (25 %), intra-arterial (IA) thrombolysis plus EVT (13 %) and IV?+?IA thrombolysis plus EVT (7 %). Intrahospital time delay until start of EVT was 91 and 99 min in anterior and vertebrobasilar circulation stroke, respectively. Average duration of EVT was 60 min. Overall thrombolysis in myocardial infarction grade 2/3 recanalization rate was 85 %. Stent retrievers were used in 75 %, being associated with higher recanalization rates than non-stent retrievers. Hemorrhagic complications (symptomatic and asymptomatic) occurred in 12 %. Overall vessel occlusion time was approximately 60 min longer in patients being referred from a primary care hospital for EVT.

Conclusion

This study gives an overview of procedure-related factors in current EVT practice. It gives estimates on preprocedural imaging modalities, periprocedural handling, and treatment combinations used for EVT. Patient referral for EVT from primary care hospitals is associated with longer vessel occlusion times.     

Efficacy and safety of an early Solitaire stent retrieval technique for acute ischemic stroke

Purpose

The aim of this study was to retrospectively evaluate the efficacy and safety of early pull-back of a Solitaire stent as a thrombectomy device in patients with acute ischemic stroke.

Methods

The study group comprised 23 consecutive cases presenting with acute ischemic stroke who were treated with intra-arterial therapy using the Solitaire device as a first-line endovascular procedure. The stent was deployed to cover the thrombus and then left in place for 1–2 min. Immediate angiographic results are presented. Neurologic status was assessed according to the NIH Stroke Scale score (NIHSS) and the modified Rankin Scale (mRS) score.

Results

Successful recanalization (TICI grade ≥2b) was achieved in 21 of the 23 (91.3 %) treated vessels, and 6 of the patients showed immediate flow restoration after the deployment of the first stent. The mean number of passes for maximal recanalization was 1.96. There were no symptomatic procedure-related complications. Of the cases, 34.8 % improved by >10 points on the NIHSS at discharge; 30.4 % of cases revealed good functional outcome (mRS score 0–2) at 90 days.

Conclusions

The early retrieval technique with the Solitaire stent appears to be a safe and effective method in patients with acute ischemic stroke.     

Tissue at risk in acute stroke patients treated beyond 8 h after symptom onset

Introduction

The decision on thrombolytics administration is usually based on a generalized, rigid time-based rule rather than an individualized evaluation of the “tissue at risk of infarction” which is the target of the recanalization therapies. The goals of our article are to assess whether there is tissue at risk of infarction in a group of acute stroke patients treated beyond 8 h after symptom onset and to investigate the baseline imaging and clinical features that predict the fate of this tissue at risk.

Methods

We retrospectively reviewed a series of patients with acute ischemic stroke treated with endovascular recanalization therapies beyond 8 h after symptom onset. The tissue at risk was calculated as the difference between the infarct volumes on baseline and follow-up imaging (infarct growth). We analyzed the epidemiological distribution of infarct growth, and we performed a multivariate regression analysis to identify the baseline variables that predict infarct growth.

Results

Our study group included 75 patients (65?±?13.8 years, baseline National Institutes of Health Stroke Scale 14?±?4.9, time to treatment 15.2?±?8.7 h). The mean infarct growth was 78.6?±?95.0 cc (p?<?0.001), and, overall, the infarct growth was greater when the baseline volume of infarct tissue was small (p?<?0.001) and in the case of a unsuccessful arterial recanalization (p?=?0.001).

Conclusions

There is potentially salvageable ischemic tissue at risk in acute stroke patients treated beyond 8 h after symptom onset.     

Stability of ischemic core volume during the initial hours of acute large vessel ischemic stroke in a subgroup of mechanically revascularized patients

Introduction

This study aimed to relate growth of the infarct core with time to recanalization in patients receiving mechanical recanalization in whom the time of recanalization is known.

Methods

We analyzed data from patients with anterior circulation acute ischemic stroke who underwent mechanical recanalization. Demographic and angiographic characteristics, initial apparent diffusion coefficient (ADC) infarct volume, time-to-peak defect volume, revascularization grade, 24–48 h nonenhanced computed tomography (CT) infarct volume, symptom onset to recanalization time, diffusion-weighted imaging to recanalization time, and discharge National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores were compared between minimal and substantial infarct growth groups. Substantial infarct growth was defined as an increase of infarct volume >10 cm³ assessed by subtracting initial ADC infarct core volume from infarct volume at 24–48 h CT.

Results

Of 25 patients, 9 had minimal infarct growth (median 0 cm³, interquartile range (IQR) ?3 to 5 cm³) and 16 had substantial infarct growth (median 103 cm³, IQR 48–132 cm³). Patients with minimal infarct growth had a median time from symptom onset to recanalization of 329 min (IQR 314–412 min) and a median time from imaging to recanalization of 231 min (IQR 198–309 min). On univariate analysis, minimal infarct growth was related to male gender (p?=?0.04), smaller initial ADC volume (p?=?0.04), higher recanalization grade (p?<?0.001), and lower discharge NIHSS (p?=?0.04) and mRS grades (p?=?0.04).

Conclusion

There was no or minimal infarct core growth in at least one third of patients despite an exceptionally long median time from magnetic resonance imaging to recanalization of almost 4 h.     

Dual-energy computed tomography for the assessment of early treatment effects of regorafenib in a preclinical tumor model: comparison with dynamic contrast-enhanced CT and conventional contrast-enhanced single-energy CT

Objectives

The potential diagnostic value of dual-energy computed tomography (DE-CT) compared to dynamic contrast-enhanced CT (DCE-CT) and conventional contrast-enhanced CT (CE-CT) in the assessment of early regorafenib treatment effects was evaluated in a preclinical setting.

Methods

A rat GS9L glioma model was examined with contrast-enhanced dynamic DE-CT measurements (80 kV/140 kV) for 4 min before and on days 1 and 4 after the start of daily regorafenib or placebo treatment. Tumour time-density curves (0-240 s, 80 kV), DE-CT (60 s) derived iodine maps and the DCE-CT (0-30 s, 80 kV) based parameters blood flow (BF), blood volume (BV) and permeability (PMB) were calculated and compared to conventional CE-CT (60 s, 80 kV).

Results

The regorafenib group showed a marked decrease in the tumour time-density curve, a significantly lower iodine concentration and a significantly lower PMB on day 1 and 4 compared to baseline, which was not observed for the placebo group. CE-CT showed a significant decrease in tumour density on day 4 but not on day 1. The DE-CT-derived iodine concentrations correlated with PMB and BV but not with BF.

Conclusions

DE-CT allows early treatment monitoring, which correlates with DCE-CT. Superior performance was observed compared to single-energy CE-CT.

Key Points

? Regorafenib treatment response was evaluated by CT in a rat tumour model. ? Dual-energy contrast-enhanced CT allows early treatment monitoring of targeted anti-tumour therapies. ? Dual-energy CT showed higher diagnostic potential than conventional contrast enhanced single-energy CT. ? Dual-energy CT showed diagnostic potential comparable to dynamic contrast-enhanced CT. ? Dual-energy CT is a promising method for efficient clinical treatment response evaluation.     

Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

Purpose

Decreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).

Materials and Methods

Twenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.

Results

In 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.

Conclusion

PBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.     

Mechanische Revaskularisation beim Schlaganfall

Clinical/methodical issue

Stroke is the third most common cause of death in the developed world and the leading cause of disability worldwide. The present demographic development will lead to increased numbers of stroke patients in the future.

Standard radiological methods

Patient selection takes place by using various computer tomographic (CT) or magnetic resonance (MR) imaging modalities. For endovascular stroke treatment a modern biplane angiography suite is recommended.

Methodical innovations

Intra-arterial chemical thrombolysis was shown to be effective in achieving recanalization and improving clinical outcome. Mechanical devices were introduced in the late 1990s and the highly effective stent retriever was recently included.

Performance

Mechanical devices allows a recanalization rate of up to 90?% of affected brain vessels.

Achievements

The advantage of a stent retriever compared to other mechanical devices seems to be an improvement in good clinical outcome.

Practical recommendations

Currently, the stent retriever seems to be the definitive first choice in the use of mechanical devices for intra-arterial recanalization treatment in acute ischemic stroke.     

The value of 15-minute delayed contrast-enhanced CT to differentiate hyperattenuating adrenal masses compared with chemical shift MR imaging

Objectives

To investigate the diagnostic performance of 15-min delayed contrast-enhanced computed tomography (15-DECT) compared with that of chemical shift magnetic resonance (CSMR) imaging in differentiating hyperattenuating adrenal masses and to perform subgroup analysis in underlying malignancy and non-malignancy.

Methods

This study included 478 adrenal masses in 453 patients examined with 15-DECT and 235 masses in 217 patients examined with CSMR. Relative percentage washout (RPW) and absolute percentage washout (APW) on 15-DECT, and signal intensity index (SII) and adrenal-to-spleen ratio (ASR) on CSMR were measured. Sensitivity, specificity and accuracy of 15-DECT and CSMR were analysed for characterisation of adrenal adenoma. Subgroup analyses were performed in patients with and without underlying malignancy. Attenuation and size of the masses on unenhanced CT correlated with the risk of non-adenoma.

Results

RPW calculated from 15-DECT showed the highest diagnostic performance for characterising hyperattenuating adrenal masses regardless of underlying malignancy, and the sensitivity, specificity and accuracy were 91.7 %, 74.8 % and 88.1 %, respectively in all patients. The risk of non-adenoma increased approximately threefold as mass size increased 1 cm or as its attenuation value increased by 10 Hounsfield units.

Conclusions

15-DECT was more accurate than CSMR in characterising hyperattenuating adrenal masses regardless of underlying malignancy.

Key Points

? Delayed contrast-enhanced CT and chemical shift magnetic resonance (CSMR) characterise adrenal lesions. ? 15-min DECT is more accurate than CSMR in characterising hyperattenuating adrenal masses. ? Sensitivity of CSMR decreases as the CT attenuation of adenomas increases. ? Risk of non-adenoma is increased 2.9-fold as size increased by 1 cm. ? Risk of non-adenoma is increased 2.9-fold as attenuation increased by 10 HU.     

Clinical significance of post-interventional cerebral hyperdensities after endovascular mechanical thrombectomy in acute ischaemic stroke

Introduction

This study aims to investigate the clinical significance of post-interventional cerebral hyperdensities (PCHD) after endovascular mechanical thrombectomy in acute ischaemic stroke.

Methods

Data of 102 consecutive patients who received post-interventional CT scans within 4.5 h after mechanical thrombectomy were analysed retrospectively.

Results

Sixty-two of 102 patients (60.8 %) had PCHD on their post-interventional CT scans. The most common site of PCHD was the basal ganglia. PCHD were persisting in 13 of 62 patients (21.0 %), and transient in the remaining 49 patients (79.0 %) within 24 h. Four patients with PCHD and four patients without PCHD suffered from parenchymal haemorrhage. Neither ASA nor Clopidogrel, Tirofiban or rtPA were risk factors for PCHD. Final infarction size was congruent with or bigger than areas of PCHD in 93.3 % of cases in our series.

Conclusion

PCHD was not a risk factor for parenchymal haemorrhage in our series. The occurrence of PCHD was strongly related to the prior presence of infarction. PCHD was also a strong predictor for final infarction size.     

Long-term clinical and radiological results of endovascular internal trapping in vertebral artery dissection

Introduction

Previous reports have suggested that endovascular parent artery occlusion is an effective and safe procedure for the treatment of vertebral artery dissection (VAD). However, the results of long-term outcomes are still unclear. This study reviewed the clinical and imaging outcomes of patients with VAD treated by endovascular internal trapping.

Methods

A total of 73 patients were treated for VAD by endovascular internal trapping between March 1998 and March 2011. Patients were regularly followed up by magnetic resonance imaging, magnetic resonance angiography, and clinical examinations. Clinical outcomes were evaluated using the modified Rankin Scale.

Results

Forty-five patients had ruptured VADs, and 28 had unruptured VADs. Clinical follow-up of at least 6 months data was obtained for 61 patients (83.6 %). The follow-up period ranged from 6 to 145 months (mean?±?SD, 55.6?±?8.9 months). Two patients with ruptured VADs had recurrence (2.74 %). Cranial nerve paresis (CNP) was observed in six patients (8.21 %), spinal cord infarction in two patients (2.74 %), and a perforating artery ischemia was diagnosed in seven patients (9.59 %); all patients with CNP and five of the patients with partial Wallenberg syndrome experienced only temporary symptoms; two of the patients with partial Wallenberg syndrome had permanent neurological deficits. Despite their symptoms, most patients were in good general condition, as shown by their clinical scores.

Conclusions

The results of this study have proven that endovascular internal trapping is a stable and durable treatment for closure of VADs. Recanalization is rather rare and occurred only in ruptured cases, both within 3 months after initial treatment without rupture. CNPs were observed in 8.21 %, perforating ischemia in 9.59 %, and spinal cord infarction in 2.74 %. The former two are temporary, while the last can be a factor that affects the modified Rankin Scale. Patients rated their quality of life as good, as corroborated by their posttreatment clinical score. Endovascular internal trapping for VAD is a therapy with a satisfactory long-term outcome.     

Thrombus imaging in acute stroke: correlation of thrombus length on susceptibility-weighted imaging with endovascular reperfusion success

Objectives

Susceptibility-weighted imaging (SWI) enables visualization of thrombotic material in acute ischemic stroke. We aimed to validate the accuracy of thrombus depiction on SWI compared to time-of-flight MRA (TOF-MRA), first-pass gadolinium-enhanced MRA (GE-MRA) and digital subtraction angiography (DSA). Furthermore, we analysed the impact of thrombus length on reperfusion success with endovascular therapy.

Methods

Consecutive patients with acute ischemic stroke due to middle cerebral artery (MCA) occlusions undergoing endovascular recanalization were screened. Only patients with a pretreatment SWI were included. Thrombus visibility and location on SWI were compared to those on TOF-MRA, GE-MRA and DSA. The association between thrombus length on SWI and reperfusion success was studied.

Results

Eighty-four of the 88 patients included (95.5 %) showed an MCA thrombus on SWI. Strong correlations between thrombus location on SWI and that on TOF-MRA (Pearson’s correlation coefficient 0.918, P?<?0.001), GE-MRA (0.887, P?<?0.001) and DSA (0.841, P?<?0.001) were observed. Successful reperfusion was not significantly related to thrombus length on SWI (P?=?0.153; binary logistic regression).

Conclusions

In MCA occlusion thrombus location as seen on SWI correlates well with angiographic findings. In contrast to intravenous thrombolysis, thrombus length appears to have no impact on reperfusion success of endovascular therapy.

Key Points

? SWI helps in assessing location and length of thrombi in the MCA ? SWI, MRA and DSA are equivalent in detecting the MCA occlusion site ? SWI is superior in identifying the distal end of the thrombus ? Stent retrievers should be deployed over the distal thrombus end ? Thrombus length did not affect success of endovascular reperfusion guided by SWI     

Assessment of the diagnostic value of dual-energy CT and MRI in the detection of iatrogenically induced injuries of anterior cruciate ligament in a porcine model

Introduction

Magnetic resonance imaging (MRI) is the standard of reference for the non-invasive evaluation of ligament injuries of the knee. The development of dual-energy CT (DE-CT) made it possible to differentiate between tissues of different density by two simultaneous CT measurements with different tube voltages. This approach enables DE-CT to discriminate ligament structures without intra-articular contrast media injection. The aims of this study were on the one hand to determine the delineation of the anterior cruciate ligament (ACL) and on the other hand to assess the diagnostic value of DE-CT and MRI in the detection of iatrogenically induced injury of the ACL in a porcine knee joint model.

Materials and methods

Twenty porcine hind legs, which were placed in a preformed cast in order to achieve a standardized position, were scanned using DE-CT. Thereafter, a 1.5-T MRI using a standard protocol was performed. The imaging procedures were repeated with the same parameters after inducing defined lesions (total or partial incision) on the ACL arthroscopically. After post-processing, two radiologists and two orthopedic surgeons first analyzed the delineation of the ACL and then, using a consensus approach, the iatrogenically induced lesions. The result of the arthrotomy was defined as the standard of reference.

Results

The ACL could be visualized both on DE-CT and MRI in 100% of the cases. As for the MRI, the sensitivity and specificity of detecting the cruciate ligament lesion respectively compared with the defined arthrotomy was 66.7% and 78.6% for intact cruciate ligaments, 100% and 75% in the case of a complete lesion, 33.3% and 78.6% for lesions of the anteromedial bundle, and 0% and 100% for lesions of the posterolateral bundle. In comparison, DE-CT demonstrated a sensitivity and specificity of 66.7% and 71.4% in the case of intact cruciate ligaments, 75% and 68.8% in the case of completely discontinued ACLs, 0% and 92.9% in the case of lesions of the anteromedial bundle, and 25% and 87.5% in the case of lesions of the posterolateral bundle.

Conclusions

The present ex vivo experiment shows that both study modalities (DE-CT and MRI) are equal with regard to the delineation of the ACL, while MRI achieved higher sensitivity and specificity regarding iatrogenically induced complete ACL lesions. DE-CT could be a possible alternative to MRI for certain indications in the diagnosis of a knee ligament injury.     

Predictive factors of outcome and hemorrhage after acute ischemic stroke treated by mechanical thrombectomy with a stent-retriever

Introduction

The study attempts to identify notable factors predicting poor outcome, death, and intracranial hemorrhage in patients with acute ischemic stroke undergoing mechanical thrombectomy with stent retriever. These data could be useful to improve the selection of patients for thrombectomy.

Methods

Patients with acute ischemic stroke treated with the Solitaire FR device were retrospectively analyzed from a prospectively collected database. We assessed the effect of selected demographic characteristics, clinical and imaging factors on poor outcome at 3 months (modified Rankin score 3–6), mortality at 3 months, and hemorrhage at day 1 (symptomatic and asymptomatic).

Results

From May 2010 to April 2012, 59 consecutive patients with an acute ischemic stroke underwent mechanical thrombectomy. At 3 months, 57.6 % of the patients were functionally independent (modified Rankin Scale 0–2) and mortality was 20.4 %. Multivariate analyses revealed that a thrombus length?>?14 mm (p?=?0.02; OR 7.55; 95 % CI 1.35–42.31) and longer endovascular procedure duration (p?=?0.01; OR 1.04; 95 % CI 1.01–1.07) were independently associated with poor outcome. A higher baseline Alberta Stroke Program Early CT (ASPECT) score (p?=?0.04; OR 0.79 per point; 95 % CI 0.63–0.99) and successful recanalization (p?=?0.02; OR 0.07; 95 % CI 0.01–0.72) were independent predictors of good functional outcome. Baseline ASPECT score (p?<?0.01; OR 0.65; 95 % CI 0.54–0.78) independently predicted symptomatic intracranial hemorrhage at day 1.

Conclusion

Absolute baseline ASPECT score reflects early symptomatic hemorrhage risk and functional outcome at 3 months. Thrombus length measured on MRI play an important role on functional outcome at 3 months after thrombectomy. Further analyses are needed to determine its importance in the selection of patients for mechanical thrombectomy.     

Transjugular Endovascular Recanalization of Splenic Vein in Patients with Regional Portal Hypertension Complicated by Gastrointestinal Bleeding

Purpose

Regional portal hypertension (RPH) is an uncommon clinical syndrome resulting from splenic vein stenosis/occlusion, which may cause gastrointestinal (GI) bleeding from the esophagogastric varices. The present study evaluated the safety and efficacy of transjugular endovascular recanalization of splenic vein in patients with GI bleeding secondary to RPH.

Methods

From December 2008 to May 2011, 11 patients who were diagnosed with RPH complicated by GI bleeding and had undergone transjugular endovascular recanalization of splenic vein were reviewed retrospectively. Contrast-enhanced computed tomography revealed splenic vein stenosis in six cases and splenic vein occlusion in five. Etiology of RPH was chronic pancreatitis (n = 7), acute pancreatitis with pancreatic pseudocyst (n = 2), pancreatic injury (n = 1), and isolated pancreatic tuberculosis (n = 1).

Results

Technical success was achieved in 8 of 11 patients via the transjugular approach, including six patients with splenic vein stenosis and two patients with splenic vein occlusion. Two patients underwent splenic vein venoplasty only, whereas four patients underwent bare stents deployment and two covered stents. Splenic vein pressure gradient (SPG) was reduced from 21.5 ± 7.3 to 2.9 ± 1.4 mmHg after the procedure (P < 0.01). For the remaining three patients who had technical failures, splenic artery embolization and subsequent splenectomy was performed. During a median follow-up time of 17.5 (range, 3–34) months, no recurrence of GI bleeding was observed.

Conclusions

Transjugular endovascular recanalization of splenic vein is a safe and effective therapeutic option in patients with RPH complicated by GI bleeding and is not associated with an increased risk of procedure-related complications.     

Mechanical Revascularization for Acute Ischemic Stroke: A Single-Center, Retrospective Analysis

Background

Endovascular mechanical revascularization (thrombectomy) is an increasingly used method for intracranial large vessel recanalization in acute stroke. The purpose of the study was to analyze the recanalization rate, clinical outcome, and complication rate in our stroke patients treated with mechanical revascularization.

Methods

A total of 57 patients with large vessel stroke (within 3 h for anterior and 12 h for posterior circulation) were treated with mechanical revascularization at a single center during 24 months. The primary goal of endovascular treatment using different mechanical devices was recanalization of the occluded vessel. Recanalization rate (reported as thrombolysis in cerebral infarction [TICI] score), clinical outcome (reported as National Institutes of Health Stroke Scale [NIHSS] score and modified Rankin scale [mRS] score), as well as periprocedural complications were analyzed.

Results

The mean age of the patients was 63.1 ± 12.9 years, with baseline median NIHSS score of 14 (interquartile range, 9.5–19). Successful recanalization (TICI 2b or 3) was achieved in 41 (72 %) patients. Twenty patients (35 %) presented with favorable outcome (mRS ≤2) 30 days after stroke. Overall, significant neurological improvement (≥4 NIHSS point reduction) occurred in 36 (63 %) patients. A clinically significant procedure-related adverse events (vessel disruption, peri/postprocedural intracranial bleeding) defined with decline in NIHSS of ≥4 or death occurred in three (5 %) patients.

Conclusions

The study showed a high recanalization rate with improved clinical outcome and a low rate of periprocedural complications in our stroke patients treated with mechanical revascularization. Therefore, we could conclude that endovascular revascularization (primary or in combination with a bridging thrombolysis) was an effective and safe procedure for intracranial large vessel recanalization in acute stroke.     

The combination of baseline magnetic resonance perfusion-weighted imaging-derived tissue volume with severely prolonged arterial-tissue delay and diffusion-weighted imaging lesion volume is predictive of MCA-M1 recanalization in patients treated with endovascular thrombectomy

Introduction

Indices of collateral flow deficit derived from MR perfusion imaging that are predictive of MCA-M1 recanalization after intravenous thrombolysis have been recently reported. Our objective was to test the performance of such MRI-derived collateral flow indices for prediction of recanalization after endovascular thrombectomy.

Methods

Fifty-seven patients with MCA-M1 occlusion evaluated with multimodal MRI prior to thrombectomy were included. Bayesian processing allowed quantification of collateral perfusion indices like the volume of tissue with severely prolonged arterial-tissue delay (>6 s) (VolATD6). Baseline DWI lesion volume was also measured. Correlations with angiographic collateral flow grading and post-thrombectomy recanalization were assessed.

Results

VolATD6?<?27 ml or DWI lesion volume <15 ml provide the most accurate diagnosis of excellent collateral supply (p?<?0.0001). The combination of VolATD6?>?27 ml and DWI lesion volume >15 ml significantly discriminates recanalizers versus nonrecanalizers (whole cohort, p?=?0.032; MERCI cohort (n?=?50), p?=?0.024). When both criteria are positive, 76.2 % of the patients treated with the MERCI retriever do not fully recanalize (p?=?0.024). In multivariate analysis, the aforementioned combined criterion and the angiographic collateral grade are the only independent predictors of recanalization with the MERCI retriever (p?=?0.015 and 0.029, respectively).

Conclusion

Bayesian arterial-tissue delay maps and DWI maps provide a non-invasive assessment of the degree of collateral flow and a combined index that is predictive of MCA-M1 recanalization after endovascular thrombectomy. Further studies are needed to evaluate the accuracy of this index in patients treated with novel stent retriever devices.     

Role of whole-body diffusion-weighted MRI in detecting bone metastasis

Purpose

The aim of this study was to compare the results of whole-body diffusion-weighted magnetic resonance (DW-MR) imaging with staging based on computed tomography (CT) and nuclear scintigraphy using Tc99m results as the standard of reference.

Methods and materials

Seventeen patients with known malignant tumours were included in the study. The thorax and the abdomen were imaged using breath-hold diffusion-weighted imaging and T1-weighted imaging sequences in the coronal plane. Location and size of osseous metastases were documented by two experienced radiologists. Whole-body DW-MR imaging findings were compared with results obtained at skeletal scintigraphy and CT bone survey.

Results

The mean examination time for whole-body DW-MR imaging was 25.5 min. All bone metastases regardless of the size were identified with whole-body DW-MR imaging; MR imaging depicted more bone metastases than CT. Skeletal scintigraphy depicted osseous metastases in 13 patients (with greater sensitivity to the lower limb), whereas whole-body DW-MR imaging revealed osseous metastases in 13 patients (with greater sensitivity to the spine). DW-MR did not show good results for detection of rib cage metastases. The additional osseous metastases seen with MR imaging were confirmed at follow-up examinations and some had a change in therapy. MR identified 22 % more metastatic lesions when compared to bone scintigraphy and 119 % when compared to CT. Bone scintigraphy identified 80 % more metastatic lesions when compared to CT. On a per-patient basis, whole-body DW-MR imaging revealed sensitivity and specificity values of 100 %.

Conclusion

Whole-body DW-MR imaging was more sensitive in the detection of osseous metastases than were skeletal scintigraphy and CT bone survey.     

Endovascular management for retreatment of postsurgical intracranial aneurysms

Introduction

Incomplete surgical treatment of intracranial aneurysms and recurrent postsurgical aneurysms are associated with a risk of rebleeding, and additional treatment is generally recommended. Surgical retreatment may carry a risk of procedural complications due to technical difficulty. We present here our experience with the endovascular approach for the retreatment of intracranial aneurysms that were initially treated with open surgery.

Methods

From January 2002 through January 2013, a total of 43 patients with 43 postsurgical index aneurysms were identified and underwent subsequent endovascular treatment. Clinical and radiological data were retrospectively reviewed.

Results

Thirty-one patients were surgically clipped before endovascular coiling and 12 patients were nonclipped, which included wrapping. Hemorrhagic presentation occurred in 21 patients prior to coiling. The interval between the initial surgical treatment and coiling varied from 0 days to 264 months (median, 9 months). Endovascular coiling resulted in the successful occlusion of 36 aneurysms (84 %). Procedure-related complications included asymptomatic thrombus formation in six patients, symptomatic cerebral infarction in two patients, and retroperitoneal hemorrhage in one patient. Delayed cerebral infarction occurred in two patients with a deployed stent. The procedure-related permanent morbidity and mortality rates were 6.9 and 0 %, respectively. Radiological follow-up evaluations beyond 6 months were available in 26 patients (60 %), which revealed major recanalization in three patients (11.5 %). There was no rebleeding during the follow-up period, which ranged from 3 to 115 months (mean, 34.5 months).

Conclusion

Endovascular embolization may serve as a safe, efficacious, and durable treatment option in the management of postsurgical intracranial aneurysms.