133Xe-DSPECT: Bedeutung der zerebrovaskulären Reservekapazität für Diagnostik und Therapie der chronischen zerebralen Ischämie

1988 ◽  
Vol 27 (04) ◽  
pp. 127-134 ◽  
Author(s):  
P. Schmiedek ◽  
T. Kreisig ◽  
K. Einhäupl ◽  
W. Bauer ◽  
E. Moser ◽  
...  
Keyword(s):  
Blood Flow ◽  
Bypass Surgery ◽  
Reserve Capacity ◽  
Non Invasive ◽  
Flow Reserve ◽  
Diagnostik Und Therapie ◽  
Severe Reduction ◽  
Before And After ◽  
Invasive Method

Using 133Xe-DSPECT, measurements of regional cerebral blood flow (rCBF) were performed before and after stimulation with 1 g of Diamox® in 55 patients with symptomatic occlusion of the internal carotid artery (ICA) and 26 patients without evidence of brain disease (normals). In normals, a negative correlation (r = -0,74) of the Diamox-induced increase of hemispheric blood flow (reserve capacity) and rCBF at rest was observed. In 48 of the 55 patients (87%) with ICA-occlusion a reduced reserve capacity was found. The extent of reduction, however, did not correlate with the findings of transmission CT, because 15 of 21 patients (71 %) with normal CT-scans presented a moderate to severe reduction of reserve capacity. In contrast, reserve capacity corresponded to the extent of arterial collateralisation as documented by cerebral panangiography. In 31 patients EC/IC-bypass surgery was performed. In follow-up studies reserve capacity increased, especially in patients who had a severe reduction preoperatively. Therefore, the combined measurement of rCBF at rest and of reserve capacity is a sensitive, non-invasive method for the diagnosis of (even bilateral) cerebrovascular disease and can be helpful to identify patients with hemodynamic ischemia, who may benefit from EC/IC-bypass surgery.

133Xe-DSPECT: Normalwerte von zerebraler Ruhedurchblutung und Reservekapazität

1987 ◽  
Vol 26 (05) ◽  
pp. 192-197 ◽  
Author(s):  
T. Kreisig ◽  
P. Schmiedek ◽  
G. Leinsinger ◽  
K. Einhäupl ◽  
E. Moser
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebrovascular Disease ◽  
Correlation Coefficient ◽  
Regional Cerebral Blood Flow ◽  
Regression Line ◽  
Reserve Capacity ◽  
Regional Cerebral Blood ◽  
Quantitative Measurements ◽  
Before And After

Using the 133Xe-DSPECT technique, quantitative measurements of regional cerebral blood flow (rCBF) were performed before and after provocation with acetazolamide (Diamox) i. v. in 32 patients without evidence of brain disease (normals). In 6 cases, additional studies were carried out to establish the time of maximal rCBF increase which was found to be approximately 15 min p. i. 1 g of Diamox increases the rCBF from 58 ±8 at rest to 73±5 ml/100 g/min. A Diamox dose of 2 g (9 cases) causes no further rCBF increase. After plotting the rCBF before provocation (rCBFR) and the Diamox-induced rCBF increase (reserve capacity, Δ rCBF) the regression line was Δ rCBF = −0,6 x rCBFR +50 (correlation coefficient: r = −0,77). In normals with relatively low rCBF values at rest, Diamox increases the reserve capacity much more than in normals with high rCBF values before provocation. It can be expected that this concept of measuring rCBF at rest and the reserve capacity will increase the sensitivity of distinguishing patients with reversible cerebrovascular disease (even bilateral) from normals.

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

Abstract WP171: Surgical Strategy And Results Of Additional Bypass For Patients With Moyamoya Disease Refractory To Previous Surgery

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Satoshi Kuroda ◽  
Naoki Akioka ◽  
Daina Kashiwazaki ◽  
Hideo Hamada ◽  
Naoya Kuwayama ◽  
...  
Keyword(s):  
Disease Progression ◽  
Moyamoya Disease ◽  
Bypass Surgery ◽  
Posterior Cerebral Artery ◽  
Cerebral Hemodynamics ◽  
Surgical Revascularization ◽  
Surgical Strategies ◽  
Cerebrovascular Events ◽  
Before And After

Introduction —It is well known that surgical revascularization can improve cerebral hemodynamics and prevent further ischemic cerebrovascular events in moyamoya disease. However, a certain subgroup of patients repeats ischemic attacks even after surgery because of insufficient surgery or disease progression during follow-up periods. Hypothesis —Relevant designs and techniques in additional bypass surgery can resolve ischemic cerebrovascular events in patients with moyamoya disease refractory to previous bypass surgery. Methods —This study included totally 7 patients (9 hemispheres) with moyamoya disease refractory to previous bypass surgery. There were 5 children and 2 adults. They underwent previous bypass surgery in Japan and Europe 6 to 240 months before admission. Based on precise clinical and radiological analysis, cerebrovascular events were considered to occur because of insufficient bypass surgery in 5 patients and disease progression in the ipsilateral posterior cerebral artery in 2. Surgical strategies included wide craniotomy to cover the area where cerebral hemodynamics is still impaired and appropriate bypass procedures such as STA-MCA anastomosis, OA-PCA anastomosis, and indirect bypass. Using [123]I-IMP SPECT or [15]O-gas PET, cerebral hemodynamics was precisely examined before and after surgery Results —Postoperative course was uneventful and cerebral hemodynamics significantly improved in all 7 patients. Postoperative cerebral angiography revealed that additional bypass provided collateral blood flow to ischemic area before surgery. Ischemic cerebrovascular events rapidly resolved in 5 patients and gradually decreased in 2. Conclusion —This study strongly suggests adequate surgical design and procedures can resolve ischemic cerebrovascular events in patients with moyamoya disease refractory to previous bypass surgery.

scholarly journals Trochanteric Femur Fractures: Application of Skeletal Traction during Surgery Does Not Alter Soft-Tissue Microcirculation

Medicina ◽  
2021 ◽  
Vol 57 (9) ◽  
pp. 884
Author(s):  
Kenneth P. van Knegsel ◽  
Bergita Ganse ◽  
Pascal C. Haefeli ◽  
Filippo Migliorini ◽  
Mario F. Scaglioni ◽  
...  
Keyword(s):  
Blood Flow ◽  
Soft Tissue ◽  
Oxygen Saturation ◽  
Subcutaneous Tissue ◽  
Skeletal Traction ◽  
Non Invasive ◽  
Femur Fractures ◽  
Vasoactive Factors ◽  
Before And After ◽  
Haemoglobin Content

Background and Objectives: Wound infections provoked by alterations in microcirculation are major complications in the treatment of trochanteric femur fractures. Surgical fracture fixation on a traction table is the gold standard for treatment, but the effect on tissue microcirculation is unknown. Microcirculation could be impaired by the pull on the soft-tissue or by a release of vasoactive factors. We hypothesized that intraoperative traction impairs soft-tissue microcirculation. Materials and Methods: In 22 patients (14 women, eight men), average age 78 years (range 36–96 ± 14), with trochanteric femur fractures, non-invasive laser-Doppler spectrophotometry was used to assess oxygen saturation, hemoglobin content, and blood flow in the skin and subcutaneous tissue before and after application of traction. Measurements were recorded in nine locations around the greater trochanter at a depth of 2, 8, and 15 mm before and after fracture reduction by traction. Results: No differences were found in any depth with traction compared to without (oxygen saturation: p = 0.751, p = 0.308, and p = 0.955, haemoglobin content: p = 0.651, p = 0.928, and p = 0.926, blood flow: p = 0.829, p = 0.866, and p = 0.411). Conclusion: In this pilot study, the application of traction does not affect skin and subcutaneous microcirculation in the surgery of proximal femur fractures.

Abstract P225: Non-invasive Measurement of Renal Blood Flow (RBF) in Different Rat Models by Magnetic Resonance Imaging (MRI)

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Cesar A Romero ◽  
Robert Knight ◽  
Glauber Cabral ◽  
Oscar A Carretero
Keyword(s):  
Blood Flow ◽  
Sham Group ◽  
Motion Artifacts ◽  
Arterial Stenosis ◽  
7 Tesla ◽  
Hypertensive Rats ◽  
Rat Models ◽  
Non Invasive ◽  
Sd Rats ◽  
Invasive Method

Quantitative measure of RBF provides important information regarding renal physiology and pathology, in different animal’s models. Arterial Spin Labelling-MRI (ASL-MRI) is a non-invasive method to measure blood flow without exogenous contrast media, using arterial water protons labeled by radiofrequency as an endogenous tracer. However, the low signal/noise radio, and the motion artifacts are a challenge for the acquisition of RBF in small animals. Our objective is evaluated the feasibility and reproducibility of the RBF measure by ASL-MRI in different hypertensive rats models. ASL-MRI images were obtained in Sprague-Dawley (SD) rats (200-300g) under inhalation anesthesia using a 7 Tesla Varian MRI system with a spin echo imaging sequence. After 4 days the MRI studies was repeated to evaluate reproducibility, using paired sample T-test and the test-retest reliability (TR) equation. RBF was also measured in in Dahl SS rats on regular chow and spontaneous hypertensive rats (SHR). Additionally we measure the RBF in a set of animals under unilateral nephrectomy (UNx) and renal arterial stenosis (RS) before and after the surgery. Table 1 shows the mean cortical RBF in different rat strains and models. Re-test analysis showed no relevant differences, being the means of differences 9.4±35 ml/min/100g tissue (p=0.58) in SD rats. The TR was 92.4±6%. UNx increase the RBF in 69.1% in comparison with sham group. (p<0.01). After the RS the blood pressure increased and the RBF decrease 56% (p<0.01) in comparison with sham group. ASL-MRI performed with navigator correction and respiratory gating is a feasible and reproducible non-invasive method to measure RBF in several rat models.

Contrast-Free Blood Flow Velocity Profile Measurement With Ultrasound in Real-Time

2011 ◽  
Author(s):  
G. G. Koutsouridis ◽  
N. Bijnens ◽  
S. van Geldermalsen ◽  
P. J. Brands ◽  
F. N. van de Vosse ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Velocity ◽  
Profile Measurement ◽  
Doppler Measurement ◽  
Non Invasive ◽  
Hemodynamic Variables ◽  
Vascular Impedance ◽  
Velocity Profile Measurement ◽  
Invasive Method ◽  
Flow Velocity Profile

In clinical practice, ultrasound is frequently used as a non-invasive method to estimate geometric properties of large arteries such as diameter and intima-media wall thickness and in a separate Doppler measurement hemodynamic variables such as blood velocity. For the purpose of deducing biomechanical parameters and hemodynamic variables that are related to the development of Cardiovascular Disease, such as compliance and vascular impedance, the assessment of only geometry and blood velocity is not sufficient. A simultaneous and non-invasive assessment of blood flow and blood pressure is required. This can only be obtained by an accurate and simultaneous measurement of the blood velocity distribution and wall motion, which is not feasible with the commonly used Doppler technique.

scholarly journals Measurement of Blood Flow in Arteriovenous Malformations before and after Embolization Using Arterial Spin Labeling

2012 ◽  
Vol 18 (1) ◽  
pp. 42-48 ◽  
Author(s):  
L. Suazo ◽  
B. Foerster ◽  
R. Fermin ◽  
H. Speckter ◽  
C. Vilchez ◽  
...  
Keyword(s):  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Conventional Angiography ◽  
Vein Of Galen Aneurysm ◽  
Non Invasive ◽  
Shunt Occlusion ◽  
Before And After ◽  
Invasive Method ◽  
Magnetic Resonance Imaging Mri ◽  
Partially Occluded

The assessment of shunt reduction after an embolization of an arteriovenous malformation (AVM) or fistula (AVF) from conventional angiography is often difficult and may be subjective. Here we present a completely non-invasive method using magnetic resonance imaging (MRI) to measure shunt reduction. Using pulsed arterial spin labeling (PASL), we determined the relative amount of signal attributed to the shunt over 1.75 s and 6 different slices covering the lesion. This amount of signal from the shunt was related to the total signal from all slices and measured before and after embolization. The method showed a fair agreement between the PASL results and the judgement from conventional angiography. In the case of a total or subtotal shunt occlusion, PASL showed a shunt reduction between 69% and 92%, whereas in minimal shunt reduction as judged by conventional angiography, the ASL result was −6% (indicating slightly increased flow) to 35% in a partially occluded vein of Galen aneurysm. The PASL method proved to be fairly reproducible (up to 2% deviation between three measurements without interventions). On conclusion, PASL is able to reliably measure the amount of shunt reduction achieved by embolization of AVMs and AVFs.

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