The New Fully Radiopaque Aperio Hybrid Stent Retriever: Efficient and Safe? An Early Multicenter Experience.

OBJECTIVE: To investigate the visibility, safety, and efficacy of the full-length radiopaque Aperio Hybrid stent retriever (APH) in mechanical thrombectomy of large vessel occlusions. METHODS: Multicentric retrospective analysis of patients with stroke, treated with the APH due to an acute ischemic stroke by large vessel occlusions in the anterior or posterior circulation, was performed. We focused on technical and angiographic parameters including device visibility, perfusion results (modified thrombolysis in cerebral infarction scale [mTICI]), procedural times, periprocedural complications, and favorable clinical outcome (modified Rankin Scale, 0-2) at discharge and after 90 days. RESULTS: A total of 48 patients (male: n = 22, 45.8%, mean age 73 years [standard deviation (SD), ±15], median baseline National Institutes of Health Stroke Scale: 15 [2-36], n = 25, 52.1% received additional intravenous thrombolytics) were treated with the APH with a mean number of 2 device passes (SD, +3) in APH-only cases (n = 41). The median time from groin puncture to the final mTICI was 54 minutes (SD, +33). In 46 patients (95.8%), mTICI 2b-3 was achieved (mTICI 2c, 12.5%; mTICI 3, 47.9%). Favorable outcome (modified Rankin Scale <2) was achieved in 15 (32.6%) patients at discharge and in 11 of the 30 (36.7%) patients available for 90-day follow-up. Symptomatic intracranial hemorrhage was recorded in 3 of 48 cases (6.3%). Difficulties during device delivery and/or deployment occurred in 6.3% (3 of 48). APH-related adverse events did not occur. APH radiopacity was rated as good and very good in 97.9% (47 of 48). CONCLUSIONS: Mechanical thrombectomy with the APH appeared feasible, efficient, and safe. Full-length device radiopacity may facilitate thrombectomy or support to adapt the course of action during retrieval, if required.

Non-invasive imaging of living kidney donors: intraindividual comparison of multislice computed tomography angiography with magnetic resonance angiography.

BACKGROUND: Evaluation of vascular variants is crucial for donor assessment prior to living kidney transplantation. Both contrast-enhanced (CE) magnetic resonance angiography (MRA) and multislice computed tomography (MSCT) are currently used for imaging living kidney donors. Aim of this study was the comparison of the accuracy of MSCT angiography and CE-MRA for the assessment of renal vascular anatomy. METHODS: Prospective study at a university transplant center including 65 potential living kidney donors. Pre-operative imaging by MSCT angiography and CE-MRA was correlated with the findings of laparoscopic donor nephrectomy in 48 donors. RESULTS: MSCT detected significantly more patients and more kidneys with accessory arteries than CE-MRA (p < 0.05). MSCT and CE-MRA performed similarly in identifying venous and ureteral abnormalities. The overall sensitivity, specificity, and accuracy for identifying accessory arteries were 85%/97%/94% for MSCT and 54%/97%/85% for CE-MRA. The sensitivity, specificity, and accuracy for the identification of supernumerary veins were 67%/95%/92% for MSCT and 67%/98%/94% for CE-MRA, respectively. CONCLUSION: We found MSCT angiography to be more sensitive and accurate than CE-MRA in the detection of supernumerary arteries prior to living donor nephrectomy.

Acrylamido polyvinyl alcohol microspheres for uterine artery embolization: 12-month clinical and MR imaging results.

PURPOSE: To report the 12-month clinical and magnetic resonance (MR) imaging results of an ongoing two-center registry involving acrylamido polyvinyl alcohol (PVA) microspheres for uterine artery embolization (UAE) for leiomyomas. MATERIALS AND METHODS: A total of 69 patients underwent UAE with 500-700-microm, 700-900-microm, and 900-1,200-mum acrylamido PVA microspheres (BeadBlock). Thirty-three patients underwent UAE with a limited embolization (protocol A) and 36 patients underwent UAE with stasis as the angiographic endpoint (protocol B). Primary objectives were clinical efficacy measured by a leiomyoma-specific quality of life (QOL) questionnaire and infarction rate of leiomyomas on early contrast agent-enhanced MR imaging. Secondary objectives were in-hospital complications, patient satisfaction, and frequency of clinical failure. RESULTS: Bilateral embolization was technically successful in 68 of 69 patients. A significant decrease (P < .001) in symptom severity and increase in health-related QOL was observed at 3 and 12 months with no significant differences between embolization protocols. However, contrast agent-enhanced MR imaging showed a significantly lower rate of completely infarcted leiomyomas in protocol A compared with protocol B (P < .05). Early clinical failures in patients treated according to protocol A were caused by incomplete tumor infarction. Minor complications occurred in five of 69 patients. Patient satisfaction was similar between protocols. CONCLUSIONS: Acrylamido PVA microspheres are a clinically effective and safe embolic agent for UAE. The use of 500-700-microm spheres and a limited embolization results in an unacceptably high rate of failed tumor infarction. Superior imaging results and fewer repeat interventions can be achieved with use of 700-900-microm spheres and stasis as the angiographic endpoint.

Use of the 4F Rösch inferior mesenteric catheter in embolization procedures in the pelvis: a review of 300 cases.

The aim of this study is to evaluate the use of a 4F Rösch inferior mesenteric (RIM) catheter for pelvic embolization procedures. Between October 2000 and January 2006, 364 patients (357 female, 7 male; age: 23-67 years) underwent embolization of various pathologies [uterine fibroids (n = 324), pure adenomyosis of the uterus (n = 19), postpartum hemorrhage (n =1), traumatic or postoperative hemorrhage (n = 9), bleeding related to cervical cancer (n =7), AV malformation of the uterus (n = 2) and high-flow priapism (n = 2)] at a single institution. In all cases, bilateral catheterization was primarily attempted with the use of a 4F hook-shaped braided endhole catheter (Rösch-Inferior-Mesenteric, RIM-Catheter, Cordis, Miami, FL). Frequency of initial failure to catheterize the vascular territory of interest and carry out the embolization were recorded and the types of difficulty encountered were noted. Catheterization of the main stem of the vessel territory of interest with the use of a unilateral femoral approach and the 4F RIM catheter was successful in 334/364 (91.8%) the embolization cases. Bilateral catheterization of the internal iliac arteries using a single common femoral artery access and the 4F RIM catheter was achieved in 322/364 (88.5%) patients. In 12/364 (3.3%) patients, a contralateral puncture was performed and the same 4F catheter was used. In 28/364 (7.7%) cases the 4F RIM catheter was exchanged for a catheter with a cobra-shaped or sidewinder configuration. The 4F RIM catheter is a simple and valuable alternative to catheters and techniques commonly employed for pelvic artery embolization.

Uterine fibroids: contrast-enhanced MR angiography to predict ovarian artery supply--initial experience.

PURPOSE: To prospectively evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography in helping predict ovarian artery supply of uterine fibroids by using postembolization conventional aortography as the reference standard. MATERIALS AND METHODS: The protocol for the study was approved by the institutional review board, and each patient gave informed consent. Ninety consecutive women (mean age, 42.5 years; range, 33-63 years) underwent MR angiography before uterine artery embolization (UAE). The number and origin of the ovarian arteries were determined. Ovarian artery supply of fibroids was graded as very unlikely, possible, or very likely by using a scoring system based on a combination of MR angiographic findings. MR angiographic results were compared with those of conventional aortography performed after UAE in all patients and followed by selective angiography in case of a suspected ovarian artery supply of fibroids. Analysis of the association between MR angiographic grading and conventional angiography as the standard of reference was performed with a chi(2) trend test. Sensitivity and specificity, including exact 95% confidence intervals (CIs), of MR angiography were determined. RESULTS: MR angiography depicted 18 ovarian arteries (four bilateral, 10 unilateral), one with an atypical origin. Five ovarian arteries were classified as very likely; three, as possible; and 10, as very unlikely sources of arterial fibroid supply. Seven (39%) of 18 ovarian arteries detected at MR angiography were visible at conventional aortography. Fibroid supply was verified at selective angiography in five ovarian arteries in five (6%) of 90 patients. There was a strong association between MR angiographic grading and the results of conventional angiography (P = .002). Sensitivity of MR angiography in depicting ovarian artery supply (grade, possible or very likely) was 100% (five of five, 95% CI: 48%; 100%) and specificity was 77% (10 of 13, 95% CI: 46%; 95%). CONCLUSION: Contrast-enhanced MR angiography can help predict ovarian artery supply of uterine fibroids.

Does ultra-low-dose CT with a radiation dose equivalent to that of KUB suffice to detect renal and ureteral calculi?

The objective of this study was to evaluate the diagnostic yield of multislice CT using a radiation dose equivalent to that of conventional abdominal x-ray (KUB). One hundred forty-two patients were prospectively examined with ultrasound and a radically dose-reduced CT protocol (120 kV, 6.9 eff. mAs). Number and size of calculi, presence of urinary obstruction, and alternative diagnoses were recorded and confirmed by stone removal/discharge or by clinical and imaging follow-up. The mean effective whole-body dose was 0.5 mSv in men and 0.7 mSv in women. The sensitivity and specificity in detecting patients with calculi was 97% and 95% for CT and 67% and 90% for ultrasound. Urinary obstruction was similarly assessed, whereas CT identified significantly more alternative diagnoses than ultrasound (P<0.001). With regard to published data for standard-dose CT, the present CT protocol seems to be comparable in its diagnostic yield in assessing patients with calculi, and its radiation dose is equivalent to that of KUB.

Percutaneous discography: comparison of low-dose CT, fluoroscopy and MRI in the diagnosis of lumbar disc disruption.

AIM: To compare the diagnostic accuracy of low-dose computed tomography (CT), magnetic resonance imaging (MRI) and fluoroscopy in percutaneous discography in patients scheduled for lumbar spondylodesis. MATERIAL AND METHODS: Within a prospective pilot study, 18 disc segments of 11 patients with radicular or pseudoradicular pain prior to anteroposterior spondylodesis were evaluated. After injection of a mixture of non-ionic iodine-containing contrast agent and gadolinium-based contrast medium into the disc spaces, all patients underwent conventional fluoroscopy, as well as low-dose CT and MRI. The occurrence of memory pain during contrast injection was recorded. CT, MRI and fluoroscopic images were analyzed independently by two readers blinded to the clinical findings. RESULTS: There was 100% agreement between CT and MRI discography in the detection, localization and grading of degenerative changes. In contrast, conventional fluoroscopy identified only 9 of the 12 abnormal segments. Memory pain following puncture was identified in 3 of the 12 affected segments. SUMMARY: Low-dose CT and MRI discography have a similar accuracy in the assessment of disc disruption and they are superior to fluoroscopic discography.

Magnetic resonance cholangiopancreatography using a free-breathing T2-weighted turbo spin-echo sequence with navigator-triggered prospective acquisition correction.

PURPOSE: The objective of this study was to evaluate the image quality of a respiratory-triggered T2-weighted (T2w) turbo spin-echo (TSE) sequence for magnetic resonance cholangiopancreatography (MRCP) using a new method for respiratory triggering by tracking the motion of the right diaphragm [prospective acquisition correction (PACE) technique]. MATERIALS AND METHODS: Fifty consecutive patients underwent MRCP imaging applying breath-hold half-Fourier single-shot TSE sequences and the respiratory-triggered T2w TSE sequence. Qualitative evaluation grading the depiction of eight segments of the pancreaticobiliary tree and the frequency of artifacts was performed. Quantitative evaluation included calculation of the relative contrast (RC) between fluid-filled ductal structures and organ parenchyma at four segments. RESULTS: A significantly higher (P<.01) RC was measured for the respiratory-triggered T2w TSE sequence [maximum intensity projection (MIP)] for all of the four investigated segments (one of four segments for the MIP) of the pancreaticobiliary tree, as well as a significant (P<.01) improvement of visualization of all ductal segments compared with the breath-hold sequences. The frequency of artifacts was significantly lower (P<.01) compared with the breath-hold sequences. CONCLUSION: Respiratory-triggered MRCP using a T2w TSE sequence with PACE significantly improves image quality and may be included into the routine MRCP sequence protocol.

Value of dual-phase multislice CT prior to minimally invasive therapy of iatrogenic renal injuries.

PURPOSE: To evaluate the diagnostic impact of multislice computed tomography (MSCT) in treatment planning prior to transarterial coil embolization of iatrogenic renal injuries. METHODS: Nine patients (median age 54 years, range 36-66) with iatrogenic renal vascular injury were treated with superselective coil embolization. Prior to therapy, a dual-phase (40 and 120 seconds) contrast-enhanced MSCT was applied in 6 patients. Seven patients underwent renal ultrasonography. Multiplanar reconstructions of the MSCT scans were used to affirm ongoing bleeding and to localize the bleeding site at the level of the segmental or interlobar artery. MSCT and angiographic findings were compared to evaluate the accuracy of MSCT in the detection of the bleeding source prior to therapy. RESULTS: Multiplanar reconstructions of early-phase MSCT scans allowed precise identification of the bleeding interlobar or segmental artery in all 6 cases prior to angiography. In one case, MSCT was even able to detect a source of bleeding that was not revealed by selective renal angiography. CONCLUSIONS: Multiplanar reconstructions of MSCT data demonstrate not only the presence of hematoma but also confirm ongoing bleeding and the location of the feeder artery prior to minimally invasive therapy.