Temporal changes of coronary artery plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Implantation of a coronary stent results in a mechanical enlargement of the coronary lumen with stretching of the surrounding atherosclerotic plaque. Using intravascular ultrasound virtual-histology (IVUS-VH) we examined the temporal changes in composition of the plaque behind the struts (PBS) following the implantation of the everolimus eluting bioresorbable vascular scaffold (BVS). Using IVUS-VH and dedicated software, the composition of plaque was analyzed in all patients from the ABSORB B trial who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA) post-treatment and at 6-month follow-up. This dedicated software enabled analysis of the PBS after subtraction of the VH signal generated by the struts. The presence of necrotic core (NC) in contact with the lumen was also evaluated at baseline and follow-up. IVUS-VH data, recorded with s5i system, were available at baseline and 6-month follow-up in 15 patients and demonstrated an increase in both the area of PBS (2.45 ± 1.93 mm(2) vs. 3.19 ± 2.48 mm(2), P = 0.005) and the external elastic membrane area (13.76 ± 4.07 mm(2) vs. 14.76 ± 4.56 mm(2), P = 0.006). Compared to baseline there was a significant progression in the NC (0.85 ± 0.70 mm(2) vs. 1.21 ± 0.92 mm(2), P = 0.010) and fibrous tissue area (0.88 ± 0.79 mm(2) vs. 1.15 ± 1.05 mm(2), P = 0.027) of the PBS. The NC in contact with the lumen in the treated segment did not increase with follow-up (7.33 vs. 6.36%, P = 0.2). Serial IVUS-VH analysis of BVS-treated lesions at 6-month demonstrated a progression in the NC and fibrous tissue content of PBS.

Saliva/pathogen biomarker signatures and periodontal disease progression

The purpose of this study was to determine the role of saliva-derived biomarkers and periodontal pathogens during periodontal disease progression (PDP). One hundred human participants were recruited into a 12-month investigation. They were seen bi-monthly for saliva and clinical measures and bi-annually for subtraction radiography, serum and plaque biofilm assessments. Saliva and serum were analyzed with protein arrays for 14 pro-inflammatory and bone turnover markers, while qPCR was used for detection of biofilm. A hierarchical clustering algorithm was used to group study participants based on clinical, microbiological, salivary/serum biomarkers, and PDP. Eighty-three individuals completed the six-month monitoring phase, with 39 [corrected] exhibiting PDP, while 44 [corrected] demonstrated stability. Participants assembled into three clusters based on periodontal pathogens, serum and salivary biomarkers. Cluster 1 members displayed high salivary biomarkers and biofilm; 71% [corrected] of these individuals were undergoing PDP. Cluster 2 members displayed low biofilm and biomarker levels; 76% [corrected] of these individuals were stable. Cluster 3 members were not discriminated by PDP status; however, cluster stratification followed groups 1 and 2 based on thresholds of salivary biomarkers and biofilm pathogens. The association of cluster membership to PDP was highly significant (p < 0.0007). [corrected] The use of salivary and biofilm biomarkers offers potential for the identification of PDP or stability (ClinicalTrials.gov number, CT00277745).

When that tune runs through your head: A PET investigation of auditory imagery for familiar melodies

The present study used positron emission tomography (PET) to examine the cerebral activity pattern associated with auditory imagery forfamiliar tunes. Subjects either imagined the continuation of nonverbaltunes cued by their first few notes, listened to a short sequence of notesas a control task, or listened and then reimagined that short sequence. Subtraction of the activation in the control task from that in the real-tune imagery task revealed primarily right-sided activation in frontal and superior temporal regions, plus supplementary motor area(SMA). Isolating retrieval of the real tunes by subtracting activation in the reimagine task from that in the real-tune imagery task revealedactivation primarily in right frontal areas and right superior temporal gyrus. Subtraction of activation in the control condition from that in the reimagine condition, intended to capture imagery of unfamiliarsequences, revealed activation in SMA, plus some left frontal regions. We conclude that areas of right auditory association cortex, together with right and left frontal cortices, are implicated in imagery for familiartunes, in accord with previous behavioral, lesion and PET data. Retrieval from musical semantic memory is mediated by structures in the right frontal lobe, in contrast to results from previous studies implicating left frontal areas for all semantic retrieval. The SMA seems to be involved specifically in image generation, implicating a motor code in this process.

When that tune runs through your head: a PET investigation of auditory imagery for familiar melodies

The present study used positron emission tomography (PET) to examine the cerebral activity pattern associated with auditory imagery for familiar tunes. Subjects either imagined the continuation of nonverbal tunes cued by their first few notes, listened to a short sequence of notes as a control task, or listened and then reimagined that short sequence. Subtraction of the activation in the control task from that in the real-tune imagery task revealed primarily right-sided activation in frontal and superior temporal regions, plus supplementary motor area (SMA). Isolating retrieval of the real tunes by subtracting activation in the reimagine task from that in the real-tune imagery task revealed activation primarily in right frontal areas and right superior temporal gyrus. Subtraction of activation in the control condition from that in the reimagine condition, intended to capture imagery of unfamiliar sequences, revealed activation in SMA, plus some left frontal regions. We conclude that areas of right auditory association cortex, together with right and left frontal cortices, are implicated in imagery for familiar tunes, in accord with previous behavioral, lesion and PET data. Retrieval from musical semantic memory is mediated by structures in the right frontal lobe, in contrast to results from previous studies implicating left frontal areas for all semantic retrieval. The SMA seems to be involved specifically in image generation, implicating a motor code in this process.

Hearing in the mind's ear: A PET investigation of musical imagery and perception

Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.

Contrast-enhanced 3-D MRA in decision making for carotid endarterectomy: a 6-year experience

BACKGROUND: Systematic need for angiography in diagnosis of carotid artery stenosis and indication of surgical therapy is still debated. Noninvasive imaging techniques such as MR angiography (MRA) or CT angiography (CTA) offer an alternative to digital subtraction angiography (DSA) and are increasingly used in clinical practice. In this study, we present the radiological characteristics and clinical results of a series of patients operated on the basis of combined ultrasonography (US)/MRA. METHODS: This observational study included all the patients consecutively operated for a carotid stenosis in our Department from October 1998 to December 2004. The applied MRA protocol had previously been established in a large correlation study with DSA. DSA was used only in case of discordance between US and MRA. The preoperative radiological information furnished by MRA was compared with intraoperative findings. The outcome of the operation was assessed according to ECST criteria. RESULTS: Among 327 patients, preoperative MRA was performed in 278 (85%), DSA in 44 (13.5%) and CT angiography in 5 (1.5%). Most of DSA studies were performed as emergency for preparation of endovascular therapy or for reasons other than carotid stenosis. Eleven additional DSA (3.3%) complemented US/MRA, mostly because diverging diagnosis of subocclusion of ICA. No direct morbidity or intraoperative difficulty was related to preoperative MRA. Combined mortality/major morbidity rate was 0.9% (3 patients) and minor morbidity rate 5.5% (18 patients). CONCLUSIONS: This observational study describes a well-established practice of carotid surgery and supports the exclusive use of non invasive diagnostic imaging for indicating and deciding the operation.

Hemophilia A pseudoaneurysm in a patient with high responding inhibitors complicating total knee arthroplasty: embolization: a cost-reducing alternative to medical therapy

Joint hemorrhages are very common in patients with severe hemophilia. Inhibitors in patients with hemophilia are allo-antibodies that neutralize the activity of the clotting factor. After total knee replacement, rare intra-articular bleeding complications might occur that do not respond to clotting factor replacement. We report a 40-year-old male with severe hemophilia A and high responding inhibitors presenting with recurrent knee joint hemorrhage after bilateral knee prosthetic surgery despite adequate clotting factor treatment. There were two episodes of marked postoperative hemarthrosis requiring extensive use of substitution therapy. Eleven days postoperatively, there was further hemorrhage into the right knee. Digital subtraction angiography diagnosed a complicating pseudoaneurysm of the inferior lateral geniculate artery and embolization was successfully performed. Because clotting factor replacement therapy has proved to be excessively expensive and prolonged, especially in patients with inhibitors, we recommend the use of cost-effective early angiographic embolization.

Increased sensitivity in mapping task demand in visuospatial processing using reaction-time-dependent hemodynamic response predictors in rapid event-related fMRI

Searching for the neural correlates of visuospatial processing using functional magnetic resonance imaging (fMRI) is usually done in an event-related framework of cognitive subtraction, applying a paradigm comprising visuospatial cognitive components and a corresponding control task. Besides methodological caveats of the cognitive subtraction approach, the standard general linear model with fixed hemodynamic response predictors bears the risk of being underspecified. It does not take into account the variability of the blood oxygen level-dependent signal response due to variable task demand and performance on the level of each single trial. This underspecification may result in reduced sensitivity regarding the identification of task-related brain regions. In a rapid event-related fMRI study, we used an extended general linear model including single-trial reaction-time-dependent hemodynamic response predictors for the analysis of an angle discrimination task. In addition to the already known regions in superior and inferior parietal lobule, mapping the reaction-time-dependent hemodynamic response predictor revealed a more specific network including task demand-dependent regions not being detectable using the cognitive subtraction method, such as bilateral caudate nucleus and insula, right inferior frontal gyrus and left precentral gyrus.

Magnetic resonance angiography in infrapopliteal arterial disease: prospective comparison of 1.5 and 3 Tesla magnetic resonance imaging

PURPOSE: To prospectively determine the accuracy of 1.5 Tesla (T) and 3 T magnetic resonance angiography (MRA) versus digital subtraction angiography (DSA) in the depiction of infrageniculate arteries in patients with symptomatic peripheral arterial disease. PATIENTS AND METHODS: A prospective 1.5 T, 3 T MRA, and DSA comparison was used to evaluate 360 vessel segments in 10 patients (15 limbs) with chronic symptomatic peripheral arterial disease. Selective DSA was performed within 30 days before both MRAs. The accuracy of 1.5 T and 3 T MRA was compared with DSA as the standard of reference by consensus agreement of 2 experienced readers. Signal-to-noise ratios (SNR) and signal-difference-to-noise ratios (SDNRs) were quantified. RESULTS: No significant difference in overall image quality, sufficiency for diagnosis, depiction of arterial anatomy, motion artifacts, and venous overlap was found comparing 1.5 T with 3 T MRA (P > 0.05 by Wilcoxon signed rank and as by Cohen k test). Overall sensitivity of 1.5 and 3 T MRA for detection of significant arterial stenosis was 79% and 82%, and specificity was 87% and 87% for both modalities, respectively. Interobserver agreement was excellent k > 0.8, P < 0.05) for 1.5 T as well as for 3 T MRA. SNR and SDNR were significantly increased using the 3 T system (average increase: 36.5%, P < 0.032 by t test, and 38.5%, P < 0.037 respectively). CONCLUSIONS: Despite marked improvement of SDNR, 3 T MRA does not yet provide a significantly higher accuracy in diagnostic imaging of atherosclerotic lesions below the knee joint as compared with 1.5 T MRA.

Initial clinical experience with the 4-F self-expanding XPERT stent system for infrapopliteal treatment of patients with severe claudication and critical limb ischemia

PURPOSE: To evaluate the primary success and short-term patency associated with a new 4-F sheath-compatible self-expanding nitinol stent after failed conventional angioplasty of distal popliteal and infrapopliteal lesions in severe lifestyle-limiting claudication (LLC) and chronic critical limb ischemia (CLI). MATERIALS AND METHODS: Between May 2003 and July 2005, 35 patients with Rutherford category 3-5 disease (16 patients with CLI, 19 patients with LLC) underwent percutaneous transluminal angioplasty (PTA) and stent implantation. Indications for stent placement were residual stenosis, flow-limiting dissections, or elastic recoil after PTA. Before and after the intervention and during the 6-month follow-up, clinical investigation, color-flow and duplex Doppler ultrasonography, and digital subtraction angiography were performed. Technical success, primary patency at 6 months, clinical improvement as defined by Rutherford with clinical and hemodynamic measures, and complications were evaluated. RESULTS: A total of 22 patients underwent distal popliteal artery stent placement and 13 underwent tibioperoneal artery stent placement. Stent implantation was successfully performed in all patients. After stent placement, the primary cumulative patency rate for the study group at 6 months was 82%. The mean resting ankle-brachial index at baseline was 0.50 +/- 0.16 and significantly increased to 0.90 +/- 0.17 at 12-24 hours after intervention and 0.82 +/- 0.24 at latest follow-up (P < .001 for both). The sustained clinical improvement rate was 80% at the 6-month follow-up. The 6-month limb salvage rate regarding major amputation was 100%. The rate of major complications was 17%. CONCLUSIONS: Infrapopliteal application of the new nitinol stent is a safe, feasible, and effective method with good short-term patency rate in the treatment of severe LLC and chronic CLI.

Immunization of Macaca fascicularis against experimental periodontitis using a vaccine containing cysteine proteases purified from Porphyromonas gingivalis

INTRODUCTION: Periodontitis is a common infectious disease to which Porphyromonas gingivalis has been closely linked, in which the attachment tissues of the teeth and their alveolar bone housing are destroyed. We conducted a study to determine if immunization using a purified antigen could alter the onset and progression of the disease. METHODS: Using the ligature-induced model of periodontitis in Macaca fascicularis, we immunized five animals with cysteine protease purified from P. gingivalis and used an additional five animals as controls. Alveolar bone loss was measured by digital subtraction radiography. RESULTS: Immunization induced high titers of specific immunoglobuin G serum antibodies that were opsonic. Total bacterial load, levels of P. gingivalis in subgingival plaque and levels of prostaglandin E(2) in gingival crevicular fluid were significantly reduced. Onset and progression of alveolar bone loss was inhibited by approximately 50%. No manifestations of toxicity were observed. CONCLUSIONS: Immunization using a purified protein antigen from P. gingivalis inhibits alveolar bone destruction in a ligature-induced periodontitis model in M. fascicularis.

Effects of non-ionic iodinated contrast media on patient heart rate and pressures during intra-cardiac or intra-arterial injection

PURPOSE: To compare the effects on heart rate (HR), on left ventricular (LV) or arterial pressures, and the general safety of a non-ionic low-osmolar contrast medium (CM) and a non-ionic iso-osmolar CM in patients undergoing cardiac angiography (CA) or peripheral intra-arterial digital subtraction angiography (IA-DSA). MATERIALS AND METHODS: Two double-blind, randomized studies were conducted in 216 patients who underwent CA (n=120) or peripheral IA-DSA (n=96). Patients referred for CA received a low-osmolar monomeric CM (iomeprol-350, n=60) or an iso-osmolar dimeric CM (iodixanol-320; n=60). HR and LV peak systolic and end-diastolic pressures were determined before and after the first injection during left and right coronary arteriography and left ventriculography. Monitoring for all types of adverse event (AE) was performed for 24 h following the procedure. t-tests were performed to compare CM for effects on HR. Patients referred for IA-DSA received iomeprol-300 (n=49) or iodixanol-320 (n=47). HR and arterial blood pressure (BP) were evaluated before and after the first 4 injections. Monitoring for AE was performed for 4 h following the procedure. Repeated-measures ANOVA was used to compare mean HR changes across the first 4 injections, whereas changes after the first injection were compared using t-tests. RESULTS: No significant differences were noted between iomeprol and iodixanol in terms of mean changes in HR during left coronary arteriography (p=0.8), right coronary arteriography (p=0.9), and left ventriculography (p=0.8). In patients undergoing IA-DSA, no differences between CM were noted for effects on mean HR after the first injection (p=0.6) or across the first 4 injections (p=0.2). No significant differences (p>0.05) were noted in terms of effects on arterial BP in either study or on LV pressures in patients undergoing CA. Non-serious AE considered possibly CM-related (primarily headache and events affecting the cardiovascular and digestive systems) were reported more frequently by patients undergoing CA and more frequently after iodixanol (14/60 [23.3%] and 2/47 [4.3%]; CA and IA-DSA, respectively) than iomeprol (10/60 [16.7%] and 1/49 [2%], respectively). CONCLUSIONS: Iomeprol and iodixanol are safe and have equally negligible effects on HR and LV pressures or arterial BP during and after selective intra-cardiac injection and peripheral IA-DSA. CLINICAL APPLICATION: Iomeprol and iodixanol are safe and equally well tolerated with regard to cardiac rhythm and clinical preference should be based on diagnostic image quality alone.

Ultrasound diagnosis of spontaneous carotid dissection with isolated Horner syndrome

BACKGROUND AND PURPOSE: Isolated Horner syndrome without associated cranial nerve palsies or ischemic symptoms is an important presentation of spontaneous internal carotid artery dissection (sICAD). Ultrasound is often used as a screening method in these patients because cervical MRI is not always available on an emergency basis. Current knowledge on ultrasound findings in patients with sICAD presenting with isolated Horner syndrome is limited. METHODS: Patients were recruited from prospective cervical artery dissection databases of 3 tertiary care centers. Diagnosis of sICAD was confirmed by cervical MRI and MR angiography or digital subtraction angiography in all patients. Data on Doppler sonography and color duplex sonography examinations performed within 30 days of symptom onset were analyzed. RESULTS: We identified 88 patients with Horner syndrome as the only sign of sICAD. Initial ultrasound examination was performed in 72 patients after a mean time interval from symptom onset to examination of 11 (SD 8) days. The overall frequency of false-negative ultrasound findings was 31% (22 of 72 patients). It showed stenosis >or=80% or occlusion in 34 (47%) patients, and stenosis

Clinical validation of an automated vessel-segmentation software of the extracranial-carotid arteries based on 3D-MRA: A prospective study

OBJECTIVES: To determine the accuracy of automated vessel-segmentation software for vessel-diameter measurements based on three-dimensional contrast-enhanced magnetic resonance angiography (3D-MRA). METHOD: In 10 patients with high-grade carotid stenosis, automated measurements of both carotid arteries were obtained with 3D-MRA by two independent investigators and compared with manual measurements obtained by digital subtraction angiography (DSA) and 2D maximum-intensity projection (2D-MIP) based on MRA and duplex ultrasonography (US). In 42 patients undergoing carotid endarterectomy (CEA), intraoperative measurements (IOP) were compared with postoperative 3D-MRA and US. RESULTS: Mean interoperator variability was 8% for measurements by DSA and 11% by 2D-MIP, but there was no interoperator variability with the automated 3D-MRA analysis. Good correlations were found between DSA (standard of reference), manual 2D-MIP (rP=0.6) and automated 3D-MRA (rP=0.8). Excellent correlations were found between IOP, 3D-MRA (rP=0.93) and US (rP=0.83). CONCLUSION: Automated 3D-MRA-based vessel segmentation and quantification result in accurate measurements of extracerebral-vessel dimensions.

Focal laminar cortical infarcts following aneurysmal subarachnoid haemorrhage

INTRODUCTION: The aim of this prospective study was to analyse small band-like cortical infarcts after subarachnoid haemorrhage (SAH) using magnetic resonance imaging (MRI) with reference to additional digital subtraction angiography (DSA). METHODS: In a 5-year period between January 2002 and January 2007 10 out of 188 patients with aneurysmal SAH were evaluated (one patient Hunt and Hess grade I, one patient grade II, four patients grade III, two patients grade IV, and two patients grade V). The imaging protocol included serially performed MRI with diffusion- and perfusion-weighted images (DWI/PWI) at three time points after aneurysm treatment, and cerebral vasospasm (CVS) was analysed on follow-up DSA on day 7+/-3 after SAH. RESULTS: The lesions were located in the frontal lobe (n=10), in the insular cortex (n=3) and in the parietal lobe (n=1). The band-like infarcts occurred after a mean time interval of 5.8 days (range 3-10 days) and showed unexceptional adjacent thick sulcal clots. Seven out of ten patients with cortical infarcts had no or mild CVS, and in the remaining three patients DSA disclosed moderate (n=2) or severe (n=1) CVS. CONCLUSION: The infarct pattern after aneurysmal SAH includes cortical band-like lesions. In contrast to territorial infarcts or lacunar infarcts in the white matter which develop as a result of moderate or severe proximal and/or distal vasospasm visible on angiography, the cortical band-like lesions adjacent to sulcal clots may also develop without evidence of macroscopic vasospasm, implying a vasospastic reaction of the most distal superficial and intraparenchymal vessels.