scholarly journals Preoperative Surgical Risk Assessment by Evaluation of Tumor Blood Flow Using Perfusion Imaging by Computed Tomography in Transsphenoidal Surgery for Pituitary Adenoma

2020 ◽  
Author(s):  
Nakamasa Hayashi ◽  
Koichi Mitsuya ◽  
Shoichi Deguchi ◽  
Atsushi Urikura ◽  
Masahiro Endo
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Transsphenoidal Surgery ◽  
Mean Value ◽  
Tumor Diameter ◽  
Preoperative Prediction ◽  
Perfusion Studies ◽  
Incomplete Removal ◽  
Significant Difference ◽  
Suprasellar Extension

Abstract Background: Complete removal of large and giant pituitary adenomas (PAs) with suprasellar extension by transsphenoidal surgery (TSS) is sometimes difficult. Swelling and bleeding of a residual suprasellar tumor after incomplete removal via TSS can compress the surrounding neurovascular structures, resulting in postoperative complications. We measured PA blood flow by perfusion computed tomography (PCT) and assessed its usefulness in the preoperative prediction of postoperative hemorrhagic complications after TSS.Method: We performed PCT in 28 patients with PAs with suprasellar extension before TSS. Perfusion studies were performed with a 320-row multidetector computed tomography system. We measured cerebral blood volume (CBV) and cerebral blood flow (CBF) of the tumor (CBVt and CBFt) and normal-appearing white matter (CBVw and CBFw).Results: In all patients, CBVt was greater than CBVw. There was a statistically significant difference between CBFt and CBFw (p < 0.0001). The patients were divided into 2 groups according to CBFt: high CBF (CBFt> mean value) and low CBF (CBFt< mean value). There were no statistically significant differences between the 2 groups in terms of gender, age, maximum tumor diameter, suprasellar extension grade, and extent of resection. Two of the 7 patients in the high CBF group suffered from visual acuity deterioration and visual field stenosis due to postoperative hemorrhage, while no patients in the low CBF group did (p = 0.014).Conclusions: PCT may be useful in the preoperative prediction of postoperative residual tumor hemorrhage, which can be a hazardous postoperative complication after TSS for large and giant PAs.

scholarly journals Preoperative surgical risk assessment by evaluation of tumor blood flow using perfusion imaging by computed tomography in transsphenoidal surgery for pituitary adenoma

2020 ◽  
Author(s):  
Nakamasa Hayashi ◽  
Koichi Mitsuya ◽  
Shoichi Deguchi ◽  
Atsushi Urikura ◽  
Masahiro Endo
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Transsphenoidal Surgery ◽  
Mean Value ◽  
Tumor Diameter ◽  
Preoperative Prediction ◽  
Perfusion Studies ◽  
Incomplete Removal ◽  
Significant Difference ◽  
Suprasellar Extension

Abstract Background: Complete removal of large and giant pituitary adenomas (PAs) with suprasellar extension by transsphenoidal surgery (TSS) is sometimes difficult. Swelling and bleeding of a residual suprasellar tumor after incomplete removal via TSS can compress the surrounding neurovascular structures, resulting in postoperative complications. We measured PA blood flow by perfusion computed tomography (PCT) and assessed its usefulness in the preoperative prediction of postoperative hemorrhagic complications after TSS.Method: We performed PCT in 28 patients with PAs with suprasellar extension before TSS. Perfusion studies were performed with a 320-row multidetector computed tomography system. We measured cerebral blood volume (CBV) and cerebral blood flow (CBF) of the tumor (CBVt and CBFt) and normal-appearing white matter (CBVw and CBFw).Results: In all patients, CBVt was greater than CBVw. There was a statistically significant difference between CBFt and CBFw (p < 0.0001). The patients were divided into 2 groups according to CBFt: high CBF (CBFt > mean value) and low CBF (CBFt < mean value). There were no statistically significant differences between the 2 groups in terms of gender, age, maximum tumor diameter, suprasellar extension grade, and extent of resection. Two of the 7 patients in the high CBF group suffered from visual acuity deterioration and visual field stenosis due to postoperative hemorrhage, while no patients in the low CBF group did (p = 0.014).Conclusions: PCT may be useful in the preoperative prediction of postoperative residual tumor hemorrhage, which can be a hazardous postoperative complication after TSS for large and giant PAs.

Imaging studies of the hindlimbs of pacas (Cuniculus paca) bred in captivity

2010 ◽  
Vol 23 (06) ◽  
pp. 439-443 ◽  
Author(s):  
S. C. Rahal ◽  
D. P. Doiche ◽  
M. R. F. Machado ◽  
L. C. Vulcano ◽  
C. R. Teixeira ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mean Value ◽  
Imaging Studies ◽  
Anteversion Angle ◽  
Future Studies ◽  
Significant Difference ◽  
In Captivity ◽  
Inclination Angles ◽  
Norberg Angle ◽  
Ct Studies

Summary Objective: To evaluate the hindlimbs of pacas bred in captivity using radiographic and computed tomography (CT) studies. Animals: Nine mature pacas (Cuniculus paca) 5.9–8.2 kg in body weight. Methods: Radiographical aspects of the bones of the hindlimbs were evaluated, and the Norberg angle and inclination angle were measured for each hindlimb. Anteversion angle were measured in CT examination. Results: The bone anatomy of the hindlimb of the paca was similar to that of the guinea pig, apart from two lunulae and a single fabella (lateral) which were observed. The Norberg angle had mean value of 130.56º ±13.81 without any significant difference between testers. Inclination angles ranged from 142.44º ±4.82 to 145.44º ±4.09 by Hauptman’s method, and from 144.94º ±3.13 to 148.22º ±3.25 by Montavon’s method, for right and left hindlimbs respectively. Average values for the anteversion angles measured with CT ranged from 28.56º ±5.56 to 32.91º ± 2.62. Clinical significance: The data may be used in future studies comparing the paca to other rodent species. In addition, the paca could be used as an animal model in orthopaedic research.

Incidence and risk factors associated with reoperation for sellar hematoma following endoscopic transsphenoidal pituitary surgery

2020 ◽  
Vol 133 (3) ◽  
pp. 702-708 ◽  
Author(s):  
Iyan Younus ◽  
Mina M. Gerges ◽  
Saniya S. Godil ◽  
Rafael Uribe-Cardenas ◽  
Georgiana A. Dobri ◽  
...  
Keyword(s):  
Risk Factors ◽  
Pituitary Adenoma ◽  
Transsphenoidal Surgery ◽  
Severe Headache ◽  
Tumor Diameter ◽  
Median Length ◽  
Factors Associated ◽  
Postoperative Hematoma ◽  
Clot Evacuation ◽  
Suprasellar Extension

OBJECTIVEPostoperative sellar hematoma is an uncommon complication of endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma that often requires emergency surgical evacuation. Sellar hematomas can cause mass effect and compress parasellar structures, leading to clinically significant symptoms such as visual impairment and severe headache. The objective of this study was to determine the incidence and risk factors associated with reoperation for postoperative hematoma after EETS for pituitary adenoma.METHODSThe authors reviewed a prospectively acquired database of EETS for pituitary adenoma over 13 years at Weill Cornell Medicine, NewYork-Presbyterian Hospital and identified cases that required reoperation for confirmed hematoma. They also reviewed clinical and radiographic data of a consecutive series of patients undergoing EETS for pituitary adenoma who did not have postoperative hematoma, which served as the control group. Demographic data and risk factors were compared between the groups using univariate and multivariate analyses via binary logistic regression.RESULTSAmong a cohort of 583 patients undergoing EETS for pituitary adenoma, 9 patients (1.5%) required operation for sellar hematoma evacuation. All 9 patients with reoperation for sellar hematoma presented with worsening in their vision, and severe headache was present in 67%. New postoperative endocrine dysfunction developed in 78%. Clot evacuation improved vision in 88%. The mean time to hematoma evacuation was 4.5 days. The median length of stay for patients with sellar hematoma was 8 days (range 4–210 days) compared with a median length of stay of 3 days (range 1–32 days) for the control patients (p < 0.005). Significant risk factors in univariate analysis were tumor diameter ≥ 30 mm (p < 0.005), suprasellar extension (p < 0.005), tumor volume (p < 0.005), cavernous sinus invasion (p < 0.05), gonadotroph histology (p < 0.05), antiplatelet use (p < 0.05), and elevated BMI (p < 0.05). On multivariate analysis, tumor diameter ≥ 30 mm (OR 4.555, CI 1.30–28.90; p < 0.05) and suprasellar extension (OR 1.048, CI 1.01–1.10; p < 0.05) were found to be the only independent predictors of sellar hematoma. The incidence of hematoma in tumors ≥ 30 mm was 5% (7/139).CONCLUSIONSPostoperative sellar hematoma requiring reoperation is a rare phenomenon after transsphenoidal surgery, often presenting with visual loss and headache. Clot evacuation results in improvement in vision, but long-term endocrinopathy often ensues. Tumor diameter ≥ 30 mm and suprasellar extent are the most reliable risk factors. Close postoperative scrutiny should be given to patients at high risk.

Determining the Accuracy of the Mandibular Canal Region in 3D Biomodels Fabricated from CBCT Scanned Data: A Cadaveric Study

2019 ◽  
Vol 15 (7) ◽  
pp. 645-653 ◽  
Author(s):  
Syed Yusoff Alzawawi Syed Abd Fattah ◽  
Firdaus Hariri ◽  
Phrabhakaran Nambiar ◽  
Zulkiflee Abu Bakar ◽  
Zainal Ariff Abdul Rahman
Keyword(s):  
Computed Tomography ◽  
Gold Standard ◽  
Mandibular Canal ◽  
Mean Value ◽  
Cone Beam ◽  
Cross Sectional ◽  
Measurement Protocol ◽  
Significant Difference ◽  
The Mean ◽  
Using Data

Objective:To validate the accuracy of the mandibular canal region in 3D biomodel produced by using data obtained from Cone-Beam Computed Tomography (CBCT) of cadaveric mandibles.Methods:Six hemi-mandible samples were scanned using the i-CAT CBCT system. The scanned data was transferred to the OsiriX software for measurement protocol and subsequently into Mimics software to fabricate customized cutting jigs and 3D biomodels based on rapid prototyping technology. The hemi-mandibles were segmented into 5 dentoalveolar blocks using the customized jigs. Digital calliper was used to measure six distances surrounding the mandibular canal on each section. The same distances were measured on the corresponding cross-sectional OsiriX images and the 3D biomodels of each dentoalveolar block.Results:Statistically no significant difference was found when measurements from OsiriX images and 3D biomodels were compared to the “gold standard” -direct digital calliper measurement of the cadaveric dentoalveolar blocks. Moreover, the mean value difference of the various measurements between the different study components was also minimal.Conclusion:Various distances surrounding the mandibular canal from 3D biomodels produced from the CBCT scanned data was similar to that of direct digital calliper measurements of the cadaveric specimens.

Renal Blood Flow in Twins

1998 ◽  
Vol 47 (3-4) ◽  
pp. 161-169
Author(s):  
M. K. Kornacka ◽  
E. Burzyńska ◽  
J. Gadzinowski
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Gestational Age ◽  
Clinical Symptoms ◽  
Mean Value ◽  
Control Group ◽  
Left Renal Artery ◽  
Mean Velocity ◽  
Significant Difference ◽  
And Control

AbstractThe aim of this preliminary study was the estimation of renal blood flow in 16 premature newborns from twin pregnancies with mean body weight 1270 g and mean gestational age 29 weeks.In control group we have 16 singleton newborns with mean gestational age 29 weeks and mean birth weight 1240 g. In both intervention and control group we have the similar clinical symptoms. The renal blood flow was carried out in the first day of life with the Acuson 128 XP Colour Doppler using the 6 and 7 MHz linear transducer. The renal blood flow parameters-PI, RI, Vmax, Vmin Vmean were measured in right and left renal arteries in theirs courses from the aorta to the renal hilus, by color sinal. In the investigation group the mean value of RI in right and left renal artery was 0,88. Mean PI in right vessel was 1,67 and in left 1,56. Mean V min in right and in left artery was 0,03 and mean V max in right artery was 0,34 and in left 0,33. Mean value of mean velocity in right vessels was 0,18 and in left 0,19.In control group we observed in right artery mean value of PI 1,74 and in left 1,6. Mean RI was 0,86 and 0,86 in right vessel in left vessel. Mean V min was 0,05 in right and 0,04 in left artery. Mean V max was 0,37 in right and 0,34 in left artery. Mean value of V mean was 0,19 in right artery and 0,18 in left artery.Using the student, Mann-Whitney and Shapiro-Wilk tests we have not observed statistically significant difference of Doppler parameters between control and investigation group and between the left and right artery. Although in newborns with broad PDA we noted significant higher value of RI (0,97, 0,98) than in newborns without PDA (0,78, 0,81).

Abstract 2547: Quantification of Myocardial Perfusion in Patients Using 256-Row Multidetector Computed Tomography: Evaluation of Endocardial vs. Epicardial Blood Flow

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Richard T George ◽  
Omair Yousuf ◽  
Kakuya Kitagawa ◽  
Hyuk-Jae Chang ◽  
David A Bluemke ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Multidetector Computed Tomography ◽  
Perfusion Imaging ◽  
Ct Perfusion ◽  
Spect Imaging ◽  
Slice Thickness ◽  
Mdct Angiography ◽  
Predictive Values ◽  
Perfusion Studies

Introduction: The advent of 256x0.5 mm high resolution multidetector computed tomography (MDCT) created the potential to quantify subendocardial myocardial blood flow (MBF) reduction, the hallmark of ischemia. The purpose of this study was to test the hypothesis that adenosine stress / rest 256x0.5mm MDCT can detect ischemia by measuring differences in subendo-cardial versus subepicardial MBF. Methods: Nineteen patients with abnormal SPECT perfusion studies underwent adenosine (140μg/kg/min) stress 256x0.5mm MDCT perfusion imaging (CTP): 120kV, 100mAs, 3 gantry rotations at 0.5 secs, followed by rest 256x0.5mm MDCT angiography (CTA): 120kV, 175mAs, 3 gantry rotations at 0.5 secs. CT perfusion images were reconstructed in the short axis with a 3 mm slice thickness. Endocardial and epicardial borders were defined, myocardium was sectored according to the standard 17 segment model, and divided circumferentially into endocardial and epicardial layers. The transmural perfusion ratio (TPR) was calculated by dividing the endocardial attenuation density (AD) by the epicardial AD in each sector. Ischemia was defined as TPR <0.8 in more than one sector. The TPR results were compared to the presence or absence of stenoses ≥50% on CTA and perfusion deficits on SPECT. Results: Mean TPR in abnormal and normal sectors was 0.71±0.05 and 1.01±0.06, respectively (p<0.01). Mean number of abnormal sectors for patients with no stenoses, 1-vessel, and multi-vessel disease were 1.6, 2.5, and 6.3; respectively (p<0.05). The sensitivity and specificity of TPR for detecting a stenosis ≥50% severity was 62% and 86% compared with 62% and 71% for SPECT (NS). When defining territorial ischemia as a SPECT perfusion abnormality plus a stenosis ≥50%, the sensitivity, specificity, positive and negative predictive values were 75%, 95%, 75%, and 95% for combined CTA/CTP imaging, respectively. Conclusions: The transmural perfusion ratio measured from 256x0.5mm MDCT perfusion images can detect the presence of obstructive atherosclerosis with similar accuracy compared with SPECT imaging. The combination of 256x0.5mm MDCT angiography and perfusion imaging may avoid the high false positive rate seen with SPECT imaging alone as well as improve its prediction of territorial ischemia.

Alterations in Cerebral Blood Flow in Preterm Infants with Intraventricular Hemorrhage

PEDIATRICS ◽  
1981 ◽  
Vol 68 (6) ◽  
pp. 763-769
Author(s):  
Laura R. Ment ◽  
Richard A. Ehrenkranz ◽  
Robert C. Lange ◽  
Peter T. Rothstein ◽  
Charles C. Duncan
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ct Scan ◽  
Preterm Infants ◽  
Intraventricular Hemorrhage ◽  
Mean Value ◽  
Germinal Matrix ◽  
The Mean ◽  
Xenon 133

Xenon-133 inhalation hemispheric cerebral blood flow (HCBF) determinations at one to two days and four to six days postnatally and at 37 weeks postconceptual age have been correlated with computed tomography (CT) scan and autopsy findings in 15 preterm infants weighing less than 1,250 gm at birth. Ten of these infants had germinal matrix hemorrhages (GMH) or intraventricular hemorrhages (IVH). Although HCBF obtained at one to two days showed no mean difference between the GMH/IVH group and the nonhemorrhage infants, hemispheric flow ratios showed significant discrepancies in the GMH/IVH group. In addition, in four of five patients in whom the hemorrhage appeared asymmetric on CT scan, the side of higher flow correlated with the hemorrhage. At four to six days HCBF showed a lower mean value in the GMH/IVH patients than in the nonhemorrhage patients and differences in the interhemispheric ratios in the GMH/IVH group persisted. There were no differences in the mean HCBF values or hemispheric ratios between the two groups of infants at 37 weeks postconceptual age.

Respiratory responses to intravenous and intrapulmonary CO2 in awake dogs

1978 ◽  
Vol 45 (1) ◽  
pp. 109-114 ◽  
Author(s):  
E. C. Greco ◽  
W. E. Fordyce ◽  
F. Gonzalez ◽  
P. Reischl ◽  
F. S. Grodins
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Mean Value ◽  
Low Flow ◽  
Co2 Response ◽  
Flow Rates ◽  
Ventilatory Responses ◽  
Ventilatory Drive ◽  
Significant Difference ◽  
Co2 Response Curve

Ventilatory responses to CO2 inhalation and CO2 infusion were compared in the awake dog. The CO2 was introduced directly into the systemic venous blood via a membrane gas exchanger in a femoral arteriovenous shunt circuit, and the extracorporeal blood flow, QX, was maintained constant at one of two rates: low, 0.5 l/min; or high, 2.0 l/min. A total of 13 experiments was performed in four dogs comprising 50 control and 25 inhalation and infusion observations at each of the two flow rates. Comparison of CO2-response curve slopes, S = delta V E/delta PaCO2, between CO2 inhalation and infusion showed no significant difference either within or between flow rates. The mean value of S for all conditions was 1.88 l/min per Torr with a 95% confidence interval of 1.66 -2.14. An independent additive ventilatory drive amounting to 28% of low-flow control VE was found at the highflow rate. We conclude that at constant blood flow the responses to both CO2 inhalation and infusion are hypercapnic and not significantly different.

Reproducibility of dynamic computed tomography brain perfusion measurements in patients with significant carotid artery stenosis

2009 ◽  
Vol 50 (2) ◽  
pp. 226-232 ◽  
Author(s):  
Z. Serafin ◽  
M. Kotarski ◽  
M. Karolkiewicz ◽  
R. Mindykowski ◽  
W. Lasek ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Blood Flow ◽  
Carotid Artery ◽  
Carotid Artery Stenosis ◽  
Cerebral Blood Volume ◽  
Artery Stenosis ◽  
Intraobserver Variability ◽  
Maximum Slope ◽  
Perfusion Computed Tomography ◽  
Significant Difference

Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and interexamination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Interexamination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and interexamination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The interexamination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the interexamination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver variability. Differences in CBF between two examinations as high as 30% may be considered as significant in such patients.

Clinical Comparison of the Ocular Blood Flow Tonograph and the Goldmann Applanation Tonometer

1998 ◽  
Vol 8 (3) ◽  
pp. 162-166 ◽  
Author(s):  
H. Esgin ◽  
M.L. Alimgil ◽  
S. Erda
Keyword(s):  
Blood Flow ◽  
Ocular Blood Flow ◽  
Mean Value ◽  
Applanation Tonometry ◽  
Goldmann Applanation Tonometry ◽  
Goldmann Applanation Tonometer ◽  
Significant Difference ◽  
Applanation Tonometer ◽  
Group 2 ◽  
Group 1

Purpose To compare the IOP readings of an ocular blood flow (OBF) tonograph (OBF Labs UK Ltd) with Goldmann applanation tonometry. Methods 194 patients were studied. In group 1, the software version 8.2 of the OBF tonograph was used in 214 eyes of 107 patients and in group 2, the 11.2 version of the tonograph was used in 174 eyes of 87 patients. Results We found 63% of the OBF tonograph readings to be within ±2mm Hg of the Goldmann applanation tonometry readings in group 1 and 60% in group 2. In group 1 the correlation coefficient between the readings of the two instruments was 0.71 and 0.82 in group 2. The mean value for the paired differences in group 1 was –1.34±2.75mm Hg overall and –1.04±2.91mm Hg overall in group 2. There was a significant difference between the Goldmann applanation tonometer and OBF tonograph readings in the 8–10mm Hg interval (p<0.001) in group 1, but not in group 2 (p>0.1). Conclusions The 11.2 version of the OBF tonograph is more accurate than the 8.2 version and measures IOP in a manner that corresponds well to the Goldmann applanation tonometer in the 8–10mm Hg and 21–29mm Hg intervals. It corresponds fairly well in the 11–20mm Hg interval.

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