Laser-Doppler microvascular flow of dental pulp in relation to caries progression

2021 ◽  
Author(s):  
Lidija Nemeth ◽  
Luka Birk ◽  
Leja Birk ◽  
Ksenija Cankar
Keyword(s):  
Dental Pulp ◽  
Laser Doppler ◽  
Microvascular Flow ◽  
Caries Progression

Pituitary Microcirculation: Physiological Aspects and Clinical Implications. A Laser-Doppler Flow Study during Transsphenoidal Adenomectomy

Neurosurgery ◽  
1991 ◽  
Vol 29 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Ralf Steinmeier ◽  
Rudolf Fahlbusch ◽  
Alexandros D. Powers ◽  
Andreas Dötterl ◽  
Michael Buchfelder
Keyword(s):  
Animal Experiments ◽  
Vascular Supply ◽  
Laser Doppler ◽  
Prospective Clinical Study ◽  
Current Output ◽  
Doppler Flowmetry ◽  
Laser Doppler Flow ◽  
Microvascular Flow ◽  
Transsphenoidal Adenomectomy ◽  
Size Growth

Abstract The anterior and posterior pituitary lobes (AL and PL, respectively) are assumed to differ in the type of vascular supply and structure of their microvascular networks. Animal experiments have shown that the pituitary microvascular flow differs between the two lobes, being extremely high in the PL and low in the AL. For technical reasons, it has hitherto not been possible to study pituitary microflow in humans. Laser-Doppler flowmetry (LDF) is now a well-established method for real-time monitoring of microcirculation, applicable also in humans. In a prospective clinical study, the microflow in the AL and PL was measured during transsphenoidal microsurgery in 52 patients with adenomas of different size, growth characteristics, and endocrinological activity. The mean microflow in the PL (177.7 ± 12.6 [flux]) was found to be about six times higher than that in the AL (27.4 ± 2.7 [flux]). No difference in the laser-Doppler fractional volume of the lobes could be detected (0.73 ± 0.006 [] vs. 0.77 ± 0.07 [], where [] designates the ratio of the alternating current output to the direct current output signals). Microflow within the pituitary lobes was influenced neither by the histological type nor the size of the adenoma. Additionally, LDF signal-averaging triggered by the electrocardiogram allowed detection of different characteristic pulsatile microvascular flow patterns in the AL and PL. Our findings provide strong physiological support for the idea that the angioarchitecture of the pituitary lobes differs. With this method, the AL and PL can be identified objectively during surgery. LDF might provide useful information concerning intraoperative surgical approach. (Neurosurgery 29:47-54, 1991)

T2 Mapping as a Tool for Assessment of Dental Pulp Response to Caries Progression: An in vivo MRI Study

2019 ◽  
Vol 54 (1) ◽  
pp. 24-35 ◽  
Author(s):  
Ksenija Cankar ◽  
Jernej Vidmar ◽  
Lidija Nemeth ◽  
Igor Serša
Keyword(s):  
Dental Pulp ◽  
T2 Mapping ◽  
Root Apex ◽  
Mapping Method ◽  
Assessment System ◽  
Caries Detection ◽  
Root Canals ◽  
Caries Progression ◽  
Mri Study

Among radiological methods, magnetic resonance imaging (MRI) excels in its ability to image soft tissue at great contrast and without the need of harmful radiation. This study tested whether in vivo MRI based on standard MRI sequences run on a standard clinical MRI system can be used to quantify dental pulp response to caries progression using the T2 mapping method. In the study, 74 teeth were scanned on a 3-T MRI system, and caries was assessed according to the International Caries Detection and Assessment System (ICDAS). The T2 maps were processed to obtain T2 profiles along selected root canals (from crown to apex), and the profiles were sorted according to both tooth type (single-rooted vs. molar) and ICDAS score. In all the examined dental pulps, it was found that T2 values decrease with an increase in the ICDAS score. In the coronal part of dental pulps, average T2 values of 166, 153, and 115 ms were found in ICDAS groups 0, 1–3, and 4–6, respectively. In single-rooted teeth, T2 values were found approximately constant as a function of dental pulp depth, while in multi-rooted teeth, they were found increasing in the coronal part and decreasing towards the root apex. The study confirmed that T2 mapping of dental pulp can be used to reliably quantify its response to caries progression and that it has a potential to become a complementary diagnostic tool to standard radiographic methods in the assessment of dental pulp response to caries.

Laser-Doppler measurements of concentration and velocity of moving blood cells in rat cerebral circulation

1997 ◽  
Vol 160 (1) ◽  
pp. 123-132
Author(s):  
C. BARFOD ◽  
N. AKGÖREN ◽  
M. FABRICIUS ◽  
U. DIRNAGL ◽  
M. LAURITZEN
Keyword(s):  
Blood Cells ◽  
Cerebral Circulation ◽  
Laser Doppler
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