Transesophageal Echocardiography - Dysphagia Risk in Acute Stroke (TEDRAS): a prospective, blind, randomized and controlled clinical trial.

BACKGROUND AND PURPOSE: Dysphagia is common in acute stroke and leads to worse overall outcome. Transesophageal echocardiography (TEE) is used in the diagnostic evaluation of stroke with regard to its etiology and is a known cause of postoperative dysphagia in cardiac surgery. The prevalence of dysphagia in acute stroke patients undergoing TEE remains unknown. The aim of the Transesophageal Echocardiography - Dysphagia Risk in Acute Stroke (TEDRAS) study was to assess the influence of TEE on swallowing among patients who have experienced acute stroke. METHODS: The TEDRAS study was a prospective, blind, randomized, controlled trial that included two groups of patients with acute stroke. Simple unrestricted randomization was performed, and examiners were blinded to each other's results. Swallowing was tested using flexible endoscopic evaluation of swallowing (FEES) at three different time points in the intervention group (24 h before, immediately after and 24 h after TEE) and in the control group (FEES on three consecutive days and TEE earliest after the third FEES). Validated scales were used to assess dysphagia severity for all time points as primary outcome measures. RESULTS: A total of 34 patients were randomized: 19 to the intervention group and 15 to the control group. The key findings of the repeated-measures between-group comparisons were significant increases in the intervention group for the following dysphagia measures: (1) secretion severity score (immediately after TEE: P < 0.001; 24 h after TEE: P < 0.001) and (2) Penetration-Aspiration Scale score for saliva (immediately after TEE: P < 0.001; 24 h after TEE: P = 0.007), for small (immediately after TEE: P = 0.009) and large liquid boli (immediately after TEE: P = 0.009; 24 h after TEE: P = 0.025). CONCLUSION: The results indicate a negative influence of TEE on swallowing in acute stroke patients for at least 24 hours.

A systematic review of the effects of temperature and precipitation on pollen concentrations and season timing, and implications for human health.

Climate and weather directly impact plant phenology, affecting airborne pollen. The objective of this systematic review is to examine the impacts of meteorological variables on airborne pollen concentrations and pollen season timing. Using PRISMA methodology, we reviewed literature that assessed whether there was a relationship between local temperature and precipitation and measured airborne pollen. The search strategy included terms related to pollen, trends or measurements, and season timing. For inclusion, studies must have conducted a correlation analysis of at least 5 years of airborne pollen data to local meteorological data and report quantitative results. Data from peer-reviewed articles were extracted on the correlations between seven pollen indicators (main pollen season start date, end date, peak date, and length, annual pollen integral, average daily pollen concentration, and peak pollen concentration), and two meteorological variables (temperature and precipitation). Ninety-three articles were included in the analysis out of 9,679 articles screened. Overall, warmer temperatures correlated with earlier and longer pollen seasons and higher pollen concentrations. Precipitation had varying effects on pollen concentration and pollen season timing indicators. Increased precipitation may have a short-term effect causing low pollen concentrations potentially due to "wash out" effect. Long-term effects of precipitation varied for trees and weeds and had a positive correlation with grass pollen levels. With increases in temperature due to climate change, pollen seasons for some taxa in some regions may start earlier, last longer, and be more intense, which may be associated with adverse health impacts, as pollen exposure has well-known health effects in sensitized individuals.

Cerebral oxygen saturation and cardiac output during anaesthesia in sitting position for neurosurgical procedures: a prospective observational study.

BACKGROUND: Neurosurgical operations in the dorsal cranium often require the patient to be positioned in a sitting position. This can be associated with decreased cardiac output and cerebral hypoperfusion, and possibly, inadequate cerebral oxygenation. In the present study, cerebral oxygen saturation was measured during neurosurgery in the sitting position and correlated with cardiac output. METHODS: Perioperative cerebral oxygen saturation was measured continuously with two different monitors, INVOS® and FORE-SIGHT®. Cardiac output was measured at eight predefined time points using transoesophageal echocardiography. RESULTS: Forty patients were enrolled, but only 35 (20 female) were eventually operated on in the sitting position. At the first time point, the regional cerebral oxygen saturation measured with INVOS® was 70 (sd 9)%; thereafter, it increased by 0.0187% min-1 (P<0.01). The cerebral tissue oxygen saturation measured with FORE-SIGHT® started at 68 (sd 13)% and increased by 0.0142% min-1 (P<0.01). The mean arterial blood pressure did not change. Cardiac output was between 6.3 (sd 1.3) and 7.2 (1.8) litre min-1 at the predefined time points. Cardiac output, but not mean arterial blood pressure, showed a positive and significant correlation with cerebral oxygen saturation. CONCLUSIONS: During neurosurgery in the sitting position, the cerebral oxygen saturation slowly increases and, therefore, this position seems to be safe with regard to cerebral oxygen saturation. Cerebral oxygen saturation is stable because of constant CO and MAP, while the influence of CO on cerebral oxygen saturation seems to be more relevant. CLINICAL TRIAL REGISTRATION: NCT01275898.

Time course of cerebrovascular autoregulation during extreme Trendelenburg position for robotic-assisted prostatic surgery.

Trendelenburg positioning in combination with pneumoperitoneum during robotic-assisted prostatic surgery possibly impairs cerebrovascular autoregulation. If cerebrovascular autoregulation is disturbed, arterial hypertension might induce cerebral hyperaemia and brain oedema, while low arterial blood pressure can induce cerebral ischaemia. The time course of cerebrovascular autoregulation was investigated during use of the Trendelenburg position and a pneumoperitoneum for robotic-assisted prostatic surgery using transcranial Doppler ultrasound. Cerebral blood flow velocity was correlated with arterial blood pressure and the autoregulation index (Mx) was calculated. In 23 male patients, Mx was assessed at baseline, after induction of general anaesthesia, during the Trendelenburg position (40-45°), and after repositioning. During the Trendelenburg position, Mx increased over time, indicating an impairment of cerebrovascular autoregulation. After repositioning, Mx recovered to baseline levels. It can be concluded that with longer durations of Trendelenburg position and pneumoperitoneum, cerebrovascular autoregulation deteriorates, and, therefore, blood pressure management should be adapted to avoid cerebral oedema and the duration of Trendelenburg position should be as short as possible.

Human cerebral microcirculation and oxygen saturation during propofol-induced reduction of bispectral index.

BACKGROUND: Propofol reduces cerebral blood flow (CBF) secondary to cerebral metabolic depression. However, in vitro and in vivo studies demonstrate that propofol directly dilates the vascular smooth muscle. This study investigates the effects of propofol-induced changes in bispectral index (BIS) on cerebral microcirculation and oxygenation during craniotomies. METHODS: In 21 craniotomy patients undergoing routine craniotomy, anaesthesia was maintained with propofol 4-10 mg kg⁻¹ h⁻¹ and remifentanil 0.1-0.4 µg kg⁻¹ min⁻¹. Propofol concentration was adjusted to achieve higher BIS (target 40) or lower BIS (target 20). Regional measurements of capillary venous blood flow (rvCBF), oxygen saturation (srvO2), and haemoglobin amount (rvHb) at 2 mm (grey matter) and 8 mm (white matter) cerebral depth were randomly performed at higher and lower BIS by combined laser-Doppler flowmetry and spectroscopy. Calculations: approximated arteriovenous difference in oxygen content (avDO2) and cerebral metabolic rate of oxygen (aCMRO2). RESULTS: mean values (sd). STATISTICS: Mann-Whitney test (*P<0.05). Results Human cerebral microcirculation and oxygen saturation were assessed at propofol dosages 5.1 (2.3) mg kg⁻¹ h⁻¹ [BIS 40 (9)] and 7.8 (2.1) mg kg⁻¹ h⁻¹ [BIS 21 (7)]. Propofol-induced reduction in BIS resulted in increased srvO2 (P=0.018), and decreased avDO2 (P=0.025) and aCMRO(2) (P=0.022), in 2 mm cerebral depth, while rvCBF and rvHb remained unchanged. In 8 mm cerebral depth, srvO2, rvCBF, rvHb, and also calculated parameters avDO2 and aCMRO2 remained unaltered. CONCLUSIONS: Findings suggest alteration of the CBF/CMRO2 ratio by propofol in cortical brain regions; therefore, it might be possible that propofol affects coupling of flow and metabolism in the cerebral microcirculation.

Acute Endovascular Stroke Treatment in Germany in 2019 : Results from a Nationwide Database.

PURPOSE: Since the incidental discovery and systematic introduction of mechanical endovascular stroke treatment in 2015 there are few reports about the real-life situation in daily clinical practice. The aim of this study was to evaluate the mechanical thrombectomy data documented in the quality assurance database of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR) and the German Society of Neuroradiology (DGNR) in 2019. METHODS: We retrospectively analyzed the clinical and procedural data of all mechanical thrombectomies that were entered into the voluntary nationwide database in 2019. The information of each procedure was provided on a standardized web-based data sheet. Data were exported and analyzed by a group of experts on behalf of the DGNR. RESULTS: A total of 13,840 data sets from 158 participating centers could be analyzed. Mean age of the patients was 74 ± 13 years; 53.9% were female. Vessel occlusion was located in the anterior circulation in 87.4%, in the posterior circulation in 10.7%. On hospital admission, the median National Institutes of Health Stroke Scale (NIHSS) was 14 (lower/upper quartile 10/19); at hospital discharge, median NIHSS had dropped to 9 (lower/upper quartile 2/12; p < 0.001). Recanalization of the occluded vessel segment was successful (TICI 2b + 3) in 88.4%. The reported complication rate was 7.3%, with subarachnoid hemorrhage as the most frequent complication (3.4%), followed by parenchymal hemorrhage (1.7%) and embolization in new territories (1.2%). Overall, the median time interval from symptom onset to hospital admission was 94 min (quartiles 59/180 min), the median time from hospital admission to groin puncture was 74 min (lower/upper quartile 47/103 min), and the median duration of the procedure 43 min (lower/upper quartile 25.2/73.2 min). A comparison between primary and secondary referral revealed a significant faster symptom-to-intervention time for primary referrals, whereas in-house workflows showed no significant difference. CONCLUSION: The analysis represents the largest documented cohort of acute stroke patients treated by thrombectomy. The documentation allows for a detailed evaluation of procedural, clinical, logistic and radiation exposure data and might be used for monitoring the quality of the treatment on a nationwide scale.

Randomized Trial of 2 Self-Titrated Oral Appliances for Airway Management.

The effectiveness and predictability of 2 different oral appliance (OA) designs to reduce the respiratory event index (REI) in moderate and severe obstructive sleep apnea (OSA) patients requires elucidation. The primary aim of the trial was to determine if 2 widely used midline-traction and bilateral-thrust OA designs differ in effectiveness to reduce the REI within a single test population categorized by OSA severity. Moderate and severe adult OSA patients, who were previously prescribed continuous positive airway pressure therapy (CPAP) but were dissatisfied with it (n = 56), were studied by home-polygraphy in a randomized crossover trial using either midline-traction with restricted mouth opening (MR) or bilateral thrust with opening permitted (BP) design OAs. OAs were used nightly for 4 wk (T2) followed by a 1-wk washout period, then 4 wk (T4) using the alternate OA. REI and oxygen saturation (SaO2) were primary outcomes, while predictability and efficacy comparison of the 2 OAs were secondary outcomes. Thirty-six participants had used MR and BP OAs during both 4-wk study legs. Twenty (55.6%) MR OA-using participants, 25 (69.4%) BP OA-using participants, and 16 (44.4%) participants using both OAs had significant REI reductions. Overall baseline (T0) median REI (interquartile range) of 33.7 (20.7-54.9) was reduced to 18.0 (8.5-19.4) at T2 and to 12.5 (8.2-15.9) at T4 (P < 0.001). Comparison of the 2 sequence groups' (MR-BP and BP-MR) REI showed the median differences between T0 and T2 and T4 were highly significant (P < 0.001). Regression analysis predicted about half of all users will have REIs between 8 and 16 after 2 mo. Baseline overjet measures >2.9 mm predicted greater OA advancement at T4. Mean and minimum SaO2 did not change significantly from T0 to T2 or T4. MR and BP OA designs similarly attenuated REI in moderate and severe OSA individuals who completed the 8-wk study protocol with greater REI reduction in those with severe OSA (ClinicalTrials.gov NCT03219034).

High-intensity transient signals during laparoscopic surgery in children.

BACKGROUND: Laparoscopic interventions in children gain increasing popularity. Pneumoperitoneum as applied during laparoscopic surgery can induce gas emboli formation, but it is unclear whether this is associated with cerebral embolic events. To investigate the hypothesis that pneumoperitoneum causes cerebral emboli in children, the number and intensity of high-intensity transient signals (HITS) detected using transcranial Doppler ultrasonography were assessed before and after induction of pneumoperitoneum. METHODS: Twenty children were monitored during laparoscopic surgery. General anaesthesia was performed using sevoflurane and sufentanil or alfentanil. Pressure-controlled ventilation was adapted to maintain end-tidal Pco(2) (Pe'(co(2))) between 4.7 and 6.0 kPa. Baseline measurement of HITS rate, cerebral blood flow velocity, and mean arterial pressure (MAP) were recorded during steady-state anaesthesia before skin incision and during pneumoperitoneum with intra-abdominal pressure of 1.6-2.0 kPa applied using CO(2). RESULTS: In 14 children (70%), HITS were detected during baseline and pneumoperitoneum. Three additional children (15%) developed HITS during pneumoperitoneum only and another three children (15%) presented no HITS during the investigation period. MAP and cerebral blood flow velocity increased with pneumoperitoneum. CONCLUSIONS: HITS are present in 70% of paediatric surgical patients under balanced anaesthesia before surgical interventions. Pneumoperitoneum further increased the occurrence of HITS.

An Appeal to Standardize CT- and MR-Perfusion.

Multiple treatment options and risk assessment in cerebrovascular diseases are the actual challenges in diagnostic as well as in interventional neuroradiology.Acute ischemic stroke essentially requires rapid detection of the location and extent of infarction and tissue at risk for making treatment decisions. In the acute setting, modern multiparametric perfusion imaging protocols help to determine infarct core and adjacent penumbral tissue, and they enable the estimation of collateral flow of intra- and extracranial arteries. In subacute delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) or chronic occlusive neurovascular diseases estimation of residual and collateral flow may be even more difficult.Prediction of sufficient or insufficient supply of brain tissue may be essential to balance conservative against interventional therapies. However, so far no established reliable thresholds are available for determining tissue at acute, subacute, chronic progressive, or chronic risk.Reliable and reproducible thresholds require quantitative perfusion measurements with a calibrated instrument. But the measurement instrument is not at all defined-a variety of parameter settings, different algorithms based on multiple assumptions and a wide variety of published normal and pathologic values for perfusion parameters indicate the problem. In the following text, we explain how deep the problem may be enrooted within techniques and algorithms impeding broad use of perfusion for many clinical issues.

CT and diffusion-weighted MR imaging in randomized order: diffusion-weighted imaging results in higher accuracy and lower interrater variability in the diagnosis of hyperacute ischemic stroke.

BACKGROUND AND PURPOSE: Diffusion-weighted MRI (DWI) has become a commonly used imaging modality in stroke centers. The value of this method as a routine procedure is still being discussed. In previous studies, CT was always performed before DWI. Therefore, infarct progression could be a reason for the better result in DWI. METHODS: All hyperacute (<6 hours) stroke patients admitted to our emergency department with a National Institutes of Health Stroke Scale (NIHSS) score >3 were prospectively randomized for the order in which CT and MRI were performed. Five stroke experts and 4 residents blinded to clinical data judged stroke signs and lesion size on the images. To determine the interrater variability, we calculated kappa values for both rating groups. RESULTS: A total of 50 patients with ischemic stroke and 4 patients with transient symptoms of acute stroke (median NIHSS score, 11; range, 3 to 27) were analyzed. Of the 50 patients, 55% were examined with DWI first. The mean delay from symptom onset until CT was 180 minutes; that from symptom onset until DWI was 189 minutes. The mean delay between DWI and CT was 30 minutes. The sensitivity of infarct detection by the experts was significantly better when based on DWI (CT/DWI, 61/91%). Accuracy was 91% when based on DWI (CT, 61%). Interrater variability of lesion detection was also significantly better for DWI (CT/DWI, kappa=0.51/0.84). The assessment of lesion extent was less homogeneous on CT (CT/DWI, kappa=0.38/0.62). The differences between the 2 modalities were stronger in the residents' ratings (CT/DWI: sensitivity, 46/81%; kappa=0.38/0.76). CONCLUSIONS: CT and DWI performed with the same delay after onset of ischemic stroke resulted in significant differences in diagnostic accuracy. DWI gives good interrater homogeneity and has a substantially better sensitivity and accuracy than CT even if the raters have limited experience.

The value of REM sleep parameters in differentiating Alzheimer's disease from old-age depression and normal aging.

Pseudodementia as a common trait in elderly depressives presents a major problem in gerontopsychiatry, especially for the differential diagnosis between Old-Age Depression (OAD) and Dementia of the Alzheimer Type (DAT). The present polysomnographic study examined parameters of sleep continuity, sleep architecture, and REM sleep to differentiate DAT from OAD. The investigation was based on the theoretical framework of the cholinergic-aminergic imbalance model of depression, the cholinergic deficit hypothesis of Alzheimer's disease and the reciprocal interaction model of Non-REM/REM sleep regulation, according to which REM sleep parameters should have high discriminative value to differentiate OAD and DAT. We investigated 35 DAT patients, 39 OAD patients and 42 healthy controls for two consecutive nights in the sleep laboratory. The DAT patients were in relatively early/mild stages of the disease, the severity of depression in the OAD group was moderate to severe. Depressed patients showed characteristic 'depression-like' EEG sleep alterations, i.e. a lower sleep efficiency, a higher amount of nocturnal awakenings and decreased sleep stage 2. Sleep continuity and architecture in DAT was less disturbed. Nearly all REM sleep measures differentiated significantly between the diagnostic groups. OAD patients showed a shortened REM latency, increased REM density and a high rate of Sleep Onset REM periods (SOREM), whereas in DAT REM density was decreased in comparison to control subjects. REM latency in DAT was not prolonged as expected. To assess the discriminative power of REM sleep variables a series of discriminant analyses were conducted. Overall, 86% of patients were correctly classified, using REM density and REM latency measures. Our findings suggest that REM density as an indicator of phasic activity appears to be more sensitive as a biological marker for the differential diagnosis of OAD and DAT than REM latency. The results support the role of central cholinergic neurotransmission in REM sleep regulation and the pathogenesis of DAT and OAD.

First experiences with a high-resolution ultrasonic scanner in the diagnosis of malignant melanomas.

The use of high-resolution ultrasonic instruments with transducer frequencies above 8 MHz makes it possible to visualize malignant melanomas of a thickness of more than 0.7 mm. While the sonolucent structure has not permitted the dignity of a lesion to be judged to date, it is easy to determine the maximal tumor thickness as well as infiltration of the subcutis. Thus "low-risk" and "high-risk" melanomas may be differentiated preoperatively according to these parameters. The results are of great use for the operator to plan the extent of his intervention, as well as to select patients for prophylactic regional lymphonodectomy.

[Effects of long-term use of mesterolone on different urine metabolites in andrological patients (author's transl)]. / Auswirkung von mesterolon-langzeitgabe auf verschieden urinmetabolite des androgenstoffwechsels bei andrologischen patienten.

We studied whether long-term use of mesterolone (12 weeks and longer) changed the pattern of steroid metabolites in urine from male subjects. We noticed an increase in dehydroepiandrosterone (DHEA) levels from 211-4 +/- 130.5 ug/die to 9943.8 +/- 6564.7 ug/die in the urine of all subjects tested. This increase was significant. After mesterolone administration was discontinued, DHEA levels decreased to their initial value. DHEA levels showed the smallest increase in those subjects having high plasma FSH levels. Perhaps the delta 4 pathway of testosterone synthesis may be preferred in these three subjects. We suppose that mesterolone has a blocking effect on the delta 5 pathway of testosterone synthesis. DHEA from the DHEA-pool can be used for testosterone synthesis and mesterolone seems to block some enzymes in the synthetic pathway. We were not able to detect a decrease in plasma testosterone levels during mesterolone use because of technical problems. Moreover, our patients told us that they felt ill after discontinuing mesterolone use; it may be possible that there is a psychotropic DHEA-effect during mesterolone use.

Steroid hormone receptors in human melanoma.

Human melanomas were investigated for the presence of high-affinity estrogen-, gestagen-, and glucocorticoid-binding proteins. A statistically significant difference was found for mean estrogen receptor (ER) concentrations in melanomas of male versus female origin: female origin 37.6 (0-107) fmol/mg protein, male origin 3.9 (0-8.3) fmol/mg protein. No significant difference between sexes was found for gestragen receptors: 41.5 (0-194) fmol/mg protein for melanomas of female origin versus 99 (0-362) fmol/mg protein for male. Sucrose density gradient analyses revealed specific binding for both receptor types in the 4-5 S region as well as in the 8 S region. The binding affinities were in the same order of magnitude as reported for receptors found in typical steroid target organs. No significant difference in receptor values depending on sex was found for the glucocorticoid receptor: 19.2 (0-43) fmol/mg protein.

[The value of multi-slice computed tomography for early diagnosis of focal cerebral ischemia]. / Zur Rolle der Mehrschicht-CT in der Frühdiagnostik der fokalen zerebralen Ischämie.

The aim of this survey is the characterization of the present value of multi-slice computed tomography (MSCT) for the assessment of hyperacute cerebral ischemia based on our experience and a review of the literature. MSCT is compared with single-slice CT (SSCT) as to the diagnostic value of standard cranial CT, CT angiography (CTA) and perfusion CT. CTA obtained with MSCT surpasses CTA obtained with SSCT. For perfusion CT, the value added by MSCT is small. With regard to standard cranial CT, MSCT and SSCT are considered equivalent. CTA and perfusion CT should be used in patients with acute stroke if the indication for thrombolysis is entertained but diffusion and perfusion weighted MRI cannot be carried out. This applies to both SSCT and MSCT. If advanced MRI and advanced CT are available, MRI continues to be the preferred imaging modality.

[Radiation load to the gonads in the sclerosing treatment of varicocele]. / Strahlenbelastung der Gonaden bei der Sklerosierungsbehandlung der Varikozele.

Vague notions concerning the radiation dose to the gonads during sclerosing treatment of varicoceles have lead to the unjust neglect of this form of therapy. Accurate measurements have shown that the dose is less than the dose to the female breast resulting from chest radiographs in two planes, if the treatment proceeds without complication. Although the dose is so low, an attempt has been made to evaluate the risk.

Combination of behaviour therapy with fluvoxamine in comparison with behaviour therapy and placebo. Results of a multicentre study.

BACKGROUND: We investigated whether the combination of multi-modal behaviour therapy (BT) with fluvoxamine is superior to BT and placebo in the acute treatment of severely ill in-patients with obsessive-compulsive disorder (OCD). METHOD: In a randomised, double-blind design, 30 patients were treated for nine weeks with BT plus placebo and 30 patients with BT plus fluvoxamine (maximum dosage 300 mg, mean dose 288.1 mg). BT included exposure with response prevention, cognitive restructuring and development of alternative behaviours. RESULTS: Both groups showed a highly significant symptom reduction after treatment. There were no significant differences between the groups concerning compulsions. Obsessions were significantly more reduced in the fluvoxamine and BT group than in the placebo and BT group. Furthermore, the group BT plus fluvoxamine showed a significantly higher response rate (87.5 v. 60%) according to a previously defined response criterion. Severely depressed patients with OCD receiving BT plus placebo presented a significantly worse treatment outcome (Y-BOCS scores) than all other groups. CONCLUSIONS: The results suggest that BT should be combined with fluvoxamine when obsessions dominate the clinical picture and when a secondary depression is present.

Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: qualitative and quantitative analysis of 3D parameter maps.

OBJECT: Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of "whole brain" VPCT for detecting localization and characteristics of arterial vasospasm. METHODS: 23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values. RESULTS: 82% patients (n=19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9s), MTT (median 5.9s) and TTD (median 7.6s). CBV showed no significant differences. In 78% (n=18) focal vessel aberrations could be detected either on CTA or DSA or on both. CONCLUSION: VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions.

4D CT angiography more closely defines intracranial thrombus burden than single-phase CT angiography.

BACKGROUND AND PURPOSE: In patients with acute stroke, the location and extent of intravascular thrombi correlate with clinical and imaging outcomes and have been used to predict the success of intravenous thrombolysis. We hypothesized that 4D-CTA reconstructed from whole-brain CTP more closely outlines intracranial thrombi than conventional single-phase CTA. MATERIALS AND METHODS: Sixty-seven patients with anterior circulation occlusion were retrospectively analyzed. For 4D-CTA, temporal maximum intensity projections were calculated that combine all 30 spiral scans of the CTP examination through temporal fusion. Thrombus extent was assessed by a semi-quantitative clot burden score (0-10; in which 0 = complete unilateral anterior circulation occlusion and 10 = patent vasculature). In patients with sufficient collateral flow, the length of the filling defect and corresponding hyperdense middle cerebral artery sign on NCCT were measured. RESULTS: Clot burden on temporal maximum intensity projection (median clot burden score, 7.0; interquartile range, 5.1-8.0) was significantly lower than on single-phase CT angiography (median, 6.0; interquartile range, 4.5-7.0; P < .0001). The length of the hyperdense middle cerebral artery sign (14.30 ± 5.93 mm) showed excellent correlation with the filling defect in the middle cerebral artery on temporal maximum intensity projection (13.40 ± 6.40 mm); this filling defect was larger on single-phase CT angiography (18.08 ± 6.54 mm; P = .043). CONCLUSIONS: As the result of an increased sensitivity for collateral flow, 4D-CTA temporal maximum intensity projection more closely outlines intracranial thrombi than conventional single-phase CT angiography. Our findings can be helpful when planning acute neurointervention. Further research is necessary to validate our data and assess the use of 4D-CTA in predicting response to different recanalization strategies.