Comparison of the Sagittal Spine Lordosis by Supine Computed Tomography and Upright Conventional Radiographs in Patients with Spinal Trauma

Study Design.Retrospective data analysis.Objective.To compare the sagittal lordosis of the lumbar spine by supine computed tomography (CT) and upright conventional radiographs.Summary of Background Data.There is sparse data about position and modality dependent changes of radiographic measurements in the sagittal lumbar spine.Methods.The anatomical and functional Cobb angles of the thoracolumbar spine in 153 patients with spinal injury were measured by conventional upright sagittal radiographs and supine CT scans. Patients were assigned either to group A (n=101), with radiologically confirmed vertebral fractures, or to group B (n=52), without any osseous lesions. The interchangeability of the two imaging modalities was calculated using a ±3° and 5° range of acceptance.Results.Group A showed a mean intraindividual difference of −3.8° for both the anatomical and the functional Cobb angle. Only 25.7% and 27.7% of the 101 patients showed a difference within the tolerated ±3° margin. Using the ±5° limits, only 46 and 47 individuals fell within the acceptable range, respectively. In the patients in group B, the mean intraindividual difference was −2.1° for the anatomical and −1.5° for the functional Cobb angle. Of the 52 patients, only 14 and 13 patients, respectively demonstrated an intraindividual difference within ±3°. With regard to a threshold of ±5°, both the functional and anatomical values were within the defined margins in only 25 (48%) patients.Conclusion.The use of supine CT measurements as a baseline assessment of the sagittal lordosis of the injured thoracolumbar spine does not appear to be appropriate when upright conventional sagittal plane radiographs are used for follow-up measurements.

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Use of the sagittal cobb* angle to guide the rod bending in the treatment of thoracolumbar fractures: a retrospective clinical study

10.21203/rs.3.rs-60473/v2 ◽

2020 ◽

Author(s):

Zongpo Shi ◽

Gang Wang ◽

Zhen Jin ◽

Tao Wu ◽

Haoran Wang ◽

...

Keyword(s):

Cobb Angle ◽

Pedicle Screw ◽

Thoracolumbar Spine ◽

Adjacent Segment ◽

Thoracolumbar Fractures ◽

Connecting Rod ◽

Bending Angle ◽

Retrospective Clinical Study ◽

Group A ◽

Group B

Abstract Background: Pedicle screw fixation is a well-established technique for thoracolumbar fracture. A large number of studies have shown that the bending angle of the connecting rod has a significant correlation with the postoperative spinal stability. However, no studies have confirmed an objective indicator to guide the bending angle of the connecting rod during the operation. Our study aims to define a sagittal Cobb* angle to guide the bending angle of the connecting rod during surgery.Methods: The frontal and lateral X-ray films in 150 cases of normal thoracolumbar spine were included to measure the normal spinal sagittal Cobb* angle in each segment. The patients who underwent single segment thoracolumbar fractures and pedicle screw internal fixation surgery were included. The radiological parameters included lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA) and sacral slope (SS) were measured. The incidence of adjacent segment degeneration（ASD）two years after surgery were measured.Results: The average values of normal sagittal Cobb* angle in each segment were -5.196±3.318 degrees (T12), 2.279±3.324 degrees (L1), 7.222±2.798 degrees (L2) and 12.417±11.962 degrees (L3) respectively. The LL in the three groups was 35.20±9.12 degrees，46.26±9.68 degrees and 54.24±15.31 degrees, respectively. Comparing with the normal group, there were significant differences in group A and group C respectively (P< 0.05). The results were similar in the parameters of TL, PT and SS. The incidences of SVA>50mm in group A, group B and group C were 23.33%,12.50% and 19.23%, respectively. The parameter of PI in three groups were 41.36±12.69, 44.53±15.27 and 43.38±9.85 degrees，respectively. The incidences of ASD in group A, group B and group C 2 years after surgery were 21.67%，13.75% and 17.95%, respectively.Conclusions: The study confirmed that the sagittal Cobb* angle can be used as a reference angle for bending rods. When the bending angle of the connecting rod is 4 to 8 degrees greater than the corresponding segment sagittal Cobb* angle, the patient's spinal sagittal stability is the best two years after the operation.

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Use of the Sagittal Cobb* Angle to Guide the Rod Bending in the Treatment of Thoracolumbar Fractures：A Retrospective Clinical Study

10.21203/rs.3.rs-60473/v1 ◽

2020 ◽

Author(s):

Zongpo Shi ◽

Gang Wang ◽

Zhen Jin ◽

Tao Wu ◽

Haoran Wang ◽

...

Keyword(s):

Cobb Angle ◽

Pedicle Screw ◽

Thoracolumbar Spine ◽

Sacral Slope ◽

Adjacent Segment ◽

Connecting Rod ◽

Bending Angle ◽

Retrospective Clinical Study ◽

Group A ◽

Group B

Abstract Background: Pedicle screw fixation is a well-established technique for thoracolumbar fracture. A large number of studies have shown that the bending angle of the connecting rod has a significant correlation with the postoperative spinal stability. However, no studies have confirmed an objective indicator to guide the bending angle of the connecting rod during the operation. Our study aims to define a sagittal Cobb* angle to guide the bending angle of the connecting rod during surgery.Methods: The frontal and lateral X-ray films in 150 cases of normal thoracolumbar spine were included to measure the normal spinal sagittal Cobb* angle in each segment. The patients who underwent single segment thoracolumbar fractures and pedicle screw internal fixation surgery were included. The radiological parameters included lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), pelvic incidence (PI) and sacral slope (SS) were measured. The incidence of adjacent segment degeneration（ASD）two years after surgery were measured.Results: The average values of normal sagittal Cobb* angle in each segment were -5.196±3.318 degrees (T12), 2.279±3.324 degrees (L1), 7.222±2.798 degrees (L2) and 12.417±11.962 degrees (L3) respectively. The LL in the three groups was 35.20±9.12 degrees，46.26±9.68 degrees and 54.24±15.3 degrees, respectively. Comparing with the normal group, there were significant differences in group A and group C respectively (P< 0.05). The results were similar in the parameters of TL, PT and SS. The incidences of SVA>50mm in group A, group B and group C were 23.33%,12.50% and 19.23%, respectively. The parameter of PI in three groups were 41.36±12.69, 44.53±15.27 and 43.38±9.85 degrees，respectively. The incidences of ASD in group A, group B and group C 2 years after surgery were 21.67%，13.75% and 17.95%, respectively.Conclusions: The study confirmed that the sagittal Cobb* angle can be used as a reference angle for bending rods. When the bending angle of the connecting rod is 4 to 8 degrees greater than the corresponding segment sagittal Cobb* angle, the patient's spinal sagittal stability is the best two years after the operation.

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Use of the sagittal Cobb* angle to guide the rod bending in the treatment of thoracolumbar fractures: a retrospective clinical study

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-020-02115-5 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Zongpo Shi ◽

Gang Wang ◽

Zhen Jin ◽

Tao Wu ◽

Haoran Wang ◽

...

Keyword(s):

Cobb Angle ◽

Pedicle Screw ◽

Thoracolumbar Spine ◽

Adjacent Segment ◽

Thoracolumbar Fractures ◽

Connecting Rod ◽

Bending Angle ◽

Retrospective Clinical Study ◽

Group A ◽

Group B

Abstract Background Pedicle screw fixation is a well-established technique for thoracolumbar fracture. A large number of studies have shown that the bending angle of the connecting rod has a significant correlation with the postoperative spinal stability. However, no studies have confirmed an objective indicator to guide the bending angle of the connecting rod during the operation. Our study aims to define a sagittal Cobb* angle to guide the bending angle of the connecting rod during surgery. Methods The frontal and lateral X-ray films in 150 cases of normal thoracolumbar spine were included to measure the normal spinal sagittal Cobb* angle in each segment. The patients who underwent single segment thoracolumbar fractures and pedicle screw internal fixation surgery were included. The radiological parameters included lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), and sacral slope (SS) were measured. The incidence of adjacent segment degeneration (ASD) 2 years after surgery was measured. Results The average values of normal sagittal Cobb* angle in each segment were − 5.196 ± 3.318° (T12), 2.279 ± 3.324° (L1), 7.222 ± 2.798° (L2), and 12.417 ± 11.962° (L3), respectively. The LL in the three groups was 35.20 ± 9.12°, 46.26 ± 9.68°, and 54.24 ± 15.31°, respectively. Compared with the normal group, there were significant differences in group A and group C, respectively (p < 0.05). The results were similar in the parameters of TL, PT, and SS. The incidences of SVA > 50 mm in group A, group B, and group C were 23.33%, 12.50%, and 19.23%, respectively. The parameter of PI in three groups was 41.36 ± 12.69, 44.53 ± 15.27, and 43.38 ± 9.85°, respectively. The incidences of ASD in group A, group B, and group C 2 years after surgery were 21.67%, 13.75%, and 17.95%, respectively. Conclusions The study confirmed that the sagittal Cobb* angle can be used as a reference angle for bending rods. When the bending angle of the connecting rod is 4 to 8° greater than the corresponding segment sagittal Cobb* angle, the patient’s spinal sagittal stability is the best 2 years after the operation.

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Beta—tricalcium phosphate as a substitute for autograft in interbody fusion cages in the canine lumbar spine

Journal of Neurosurgery Spine ◽

10.3171/spi.2002.97.3.0350 ◽

2002 ◽

Vol 97 (3) ◽

pp. 350-354 ◽

Cited By ~ 10

Author(s):

Takashiro Ohyama ◽

Yoshichika Kubo ◽

Hiroo Iwata ◽

Waro Taki

Keyword(s):

Lumbar Spine ◽

Tricalcium Phosphate ◽

Interbody Fusion ◽

Donor Site ◽

Posterolateral Approach ◽

Content Type ◽

Spine Model ◽

Group A ◽

Group B ◽

Fine Print

Object. An interbody fusion cage has been introduced for cervical anterior interbody fusion. Autogenetic bone is packed into the cage to increase the rate of union between adjacent vertebral bodies. Thus, donor site—related complications can still occur. In this study a synthetic ceramic, β—tricalcium phosphate (TCP), was examined as a substitute for autograft bone in a canine lumbar spine model. Methods. In 12 dogs L-1 to L-4 vertebrae were exposed via a posterolateral approach, and discectomy and placement of interbody fusion cages were performed at two intervertebral disc spaces. One cage was filled with autograft (Group A) and the other with TCP (Group B). The lumbar spine was excised at 16 weeks postsurgery, and biomechanical, microradiographic, and histological examinations were performed. Both the microradiographic and histological examinations revealed that fusion occurred in five (41.7%) of 12 operations performed in Group A and in six (50%) of 12 operations performed in Group B. The mean percentage of trabecular bone area in the cages was 54.6% in Group A and 53.8% in Group B. There were no significant intergroup differences in functional unit stiffness. Conclusions. Good histological and biomechanical results were obtained for TCP-filled interbody fusion cages. The results were comparable with those obtained using autograft-filled cages, suggesting that there is no need to harvest iliac bone or to use allo- or xenografts to increase the interlocking strength between the cage and vertebral bone to achieve anterior cervical interbody fusion.

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The Value of Abdominal and Pelvic CT Scan in Trauma Patients With Low Injury Severity Score and High Glasgow Coma Scale

The American Surgeon ◽

10.1177/00031348211047496 ◽

2021 ◽

pp. 000313482110474

Author(s):

Tarik Wasfie ◽

Daniel Rivera ◽

Mursal Naisan ◽

Shelby Zaremba ◽

Mikayla Depuydt ◽

...

Keyword(s):

Computed Tomography ◽

Glasgow Coma Scale ◽

Physical Examination ◽

Injury Severity ◽

Surgical Intervention ◽

Trauma Patients ◽

Ct Findings ◽

Group A ◽

Fast Exam ◽

Group B

Introduction Computed tomography scans became the mainstay of emergency department (ED) evaluation of trauma patients including those with a high Glasgow Coma Scale (GCS) and a low Injury Severity Score (ISS). We elected to find the value of abdominal and pelvic CT in patients with negative physical examination and Focused Assessment of Sonography for Trauma (FAST) on arrival to the ED. Methods This study is a retrospective analysis of 901 consecutive patients from 2017 to 2019 who presented to the ED with level 2 and 3 activation criteria. Each patient received a physical examination, CT abdomen and pelvis, and FAST exam. Data were collected on external factor including GCS, ISS, age, sex, comorbidities, anticoagulation use, and surgical intervention. The patients were divided into 2 groups, Group A and B. Group A consisted of patients with a negative physical exam, FAST, and CT result. Group B included patients with a negative physical exam and FAST exam with positive CT findings. Statistical analysis was done using a Student’s t-test and chi-square test for significance value of P < .05. Institutional Review Board approval was obtained for this study. Results A total of 901 patients were analyzed which included 489 (54.3%) male and 412 (45.7%) female with a mean age of 56.2 (SD = 22.62) years. Out of the 901 patients, 461 patients received a physical, FAST, and CT exam. Group A consisted of 442 (95.9%) patients and Group B had 19 (4.1%) patients. Both groups were similar in GCS and ISS scoring with no significance difference in age, sex, comorbidities, and anticoagulation use. There was a significant difference in the ICU and hospital mean length of stay when CT scan was positive [2 (SD = 4.23) days vs. .6 (SD = 1.33) days with P < .0001 and 4.57 (SD ± 4.17) days vs. 2.5 (SD = 2.00) days with P < .0001, respectively]. The CT findings of the 19 patients in group B consisted of 6 incidentalomas, 5 vertebral compression fractures, 4 pelvic bone fractures, 1 minor liver contusion, 1 non-specific bowel thickening, 1 non-displaced rib fracture, and 1 case of small amount of free fluid in the pelvis. None of the CT findings required surgical intervention. Conclusion Computed tomography of the abdomen and pelvis in trauma patients with high GCS and low ISS with initial negative physical and FAST examination did not provide additional critical information.

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Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

Acta Veterinaria Scandinavica ◽

10.1186/s13028-019-0495-8 ◽

2019 ◽

Vol 61 (1) ◽

Author(s):

Christin Röttiger ◽

Maren Hellige ◽

Bernhard Ohnesorge ◽

Astrid Bienert-Zeit

Keyword(s):

Computed Tomography ◽

Image Quality ◽

Post Mortem ◽

Mr Images ◽

Adjacent Structures ◽

Group A ◽

Group B ◽

The Impact ◽

Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

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A direct correlation between commissural orientation and annular shape in bicuspid aortic valves: a new anatomical and computed tomography classification

Interactive CardioVascular and Thoracic Surgery ◽

10.1093/icvts/ivz325 ◽

2020 ◽

Vol 30 (5) ◽

pp. 666-670

Author(s):

Ilaria Chirichilli ◽

Francesco Giosuè Irace ◽

Luca Paolo Weltert ◽

Andrea Salica ◽

Lorenzo Guerrieri Wolf ◽

...

Keyword(s):

Computed Tomography ◽

Aortic Annulus ◽

Aortic Valves ◽

Elliptical Shape ◽

Anatomical Classification ◽

Bicuspid Aortic Valves ◽

Group A ◽

Group B ◽

Symmetrical Type

Abstract OBJECTIVES The shape of the aortic annulus is still under debate. Recent findings suggest a possible gradual spectrum of circularity from tricuspid aortic valves (TAVs), to type 1 bicuspid aortic valves (BAVs) to type 0 BAVs. BAVs have been recently classified in a symmetrical (type A), asymmetrical (type B) or very asymmetrical (type C) phenotype according to the commissural orientation (CO) (160°–180°, 140°–159° and 120°–139°, respectively). The aim of this study is to verify in BAVs the correlation between the aortic annular shape and the CO of valve cusps and to suggest a new anatomical and geometric classification of BAVs based on CO and annular shape. METHODS We retrospectively selected 191 consecutive patients who underwent both electrocardiography-gated computed tomography scan of the aortic root and transthoracic echocardiography between January 2016 and June 2019. The population was divided into 2 groups: 54 BAVs and 137 TAVs. We analysed the subgroup of BAV patients and divided them into group A, group B and group C depending on the CO. The shape of the aortic annulus was considered ‘circular’ or ‘elliptic’ according to the ellipticity index (EI).We studied the possible correlation between CO and annular shape in BAVs. We also analysed the subgroup of TAV patients studying their annular shape and EI. RESULTS After univariate linear regression, BAV patients showed a significant correlation between the CO and the EI (R = −0, 445, R2 = 0, 198, P = 0.001). As the CO decreases, the EI increases and approaches an elliptical shape. After grouping BAVs according to the CO, a mean EI of 1.10 ± 0.07 was found in group A, 1.13 ± 0.08 in group B, 1.18 ± 0.07 in group C, P = 0.0097 indicating a gradual spectrum of ellipticity with the decrease of CO. TAVs subgroup showed a mean EI of 1.27 ± 0.09, suggesting that the more the CO is reduced in BAVs, the more the annulus probably tends towards the very elliptical shape of TAVs. CONCLUSIONS This study shows a linear correlation between CO and annular shape in BAVs. In particular, the aortic annulus follows a continuous spectrum of ellipticity depending on the CO. These findings lay the groundwork for a new anatomical classification of BAVs based on CO and annular shape.

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Readjustment of abdominal computed tomography protocols in a university hospital: impact on radiation dose

Radiologia Brasileira ◽

10.1590/0100-3984.2014.0054 ◽

2015 ◽

Vol 48 (5) ◽

pp. 292-297 ◽

Cited By ~ 4

Author(s):

Ricardo Francisco Tavares Romano ◽

Priscila Silveira Salvadori ◽

Lucas Rios Torres ◽

Elisa Almeida Sathler Bretas ◽

Daniel Bekhor ◽

...

Keyword(s):

Computed Tomography ◽

Radiation Dose ◽

Clinical Suspicion ◽

University Hospital ◽

Abdominal Ct ◽

Abdominal Computed Tomography ◽

Computed Tomography Scans ◽

Group A ◽

Group B ◽

Tomography Scan

AbstractObjective:To assess the reduction of estimated radiation dose in abdominal computed tomography following the implementation of new scan protocols on the basis of clinical suspicion and of adjusted images acquisition parameters.Materials and Methods:Retrospective and prospective review of reports on radiation dose from abdominal CT scans performed three months before (group A – 551 studies) and three months after (group B – 788 studies) implementation of new scan protocols proposed as a function of clinical indications. Also, the images acquisition parameters were adjusted to reduce the radiation dose at each scan phase. The groups were compared for mean number of acquisition phases, mean CTDIvol per phase, mean DLP per phase, and mean DLP per scan.Results:A significant reduction was observed for group B as regards all the analyzed aspects, as follows: 33.9%, 25.0%, 27.0% and 52.5%, respectively for number of acquisition phases, CTDIvol per phase, DLP per phase and DLP per scan (p < 0.001).Conclusion:The rational use of abdominal computed tomography scan phases based on the clinical suspicion in conjunction with the adjusted images acquisition parameters allows for a 50% reduction in the radiation dose from abdominal computed tomography scans.

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Arthroscopic Ankle Arthrodesis

Foot & Ankle International ◽

10.3113/fai.2007.0695 ◽

2007 ◽

Vol 28 (6) ◽

pp. 695-706 ◽

Cited By ~ 98

Author(s):

Nikolaos E. Gougoulias ◽

Filon G. Agathangelidis ◽

Stephen W. Parsons

Keyword(s):

Sagittal Plane ◽

Deformity Correction ◽

Frontal Plane ◽

Ankle Arthrodesis ◽

Valgus Deformity ◽

Postoperative Treatment ◽

Average Hospital ◽

Superficial Wound ◽

Group A ◽

Group B

Background: Arthroscopic arthrodesis has been used mainly for in situ fusion of arthritic ankles without deformity. This paper presents the application of arthroscopic arthrodesis of ankles with marked deformity. Methods: The results of 78 consecutive cases of arthroscopic ankle arthrodeses, performed in 74 patients, were retrospectively evaluated. Forty-eight ankles had minor deformity (group A), whereas 30 ankles had a varus or valgus deformity of more than 15 degrees (maximum 45 degrees) (group B). The average hospital stay was 3.8 and 3.4 days in groups A and B, respectively ( p = 0.74). Postoperative treatment included ankle immobilization for 3 months. Progressive weightbearing was initiated at 2 weeks. Mean followup was 21.1 months. Results: Fusion occurred in 47 of 48 (97.9%) ankles in group A at an average time of 13.1 ± 5.8 weeks and in 29 of 30 (96.7%) ankles at 11.6 ± 2.4 weeks in group B ( p = 0.19). Unplanned operative procedures were required in 11 ankles (14.1%). One superficial wound infection occurred. Symptomatic arthritis from the adjacent joints developed in six ankles (7.7%). Postoperative ankle alignment in the frontal plane averaged 0.7 and 0.4 degrees of valgus ( p = 0.41), whereas the sagittal plane angle averaged 106 ± 4 degrees and 104.5 ± 7 degrees in groups A and B, respectively ( p = 0.22). The outcome was graded as very good in 79.2% (38 feet) in group A and 80% (24 feet) in group B, fair in 18.8% (9 feet) in group A and 16.7% (5 feet) in group B and poor in one ankle in each group ( p = 0.68). Conclusions: The arthroscopic technique offered high fusion rates and low morbidity. Deformity correction was achieved with good results.

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Comparison of 40 and 60 milliliters of contrast in assessment of the carotid artery by computed tomography angiography

Acta Radiologica ◽

10.1080/02841850802403748 ◽

2008 ◽

Vol 49 (9) ◽

pp. 1068-1078 ◽

Cited By ~ 9

Author(s):

N. Takeyama ◽

Y. Ohgiya ◽

H. Itokawa ◽

Y. Takahashi ◽

M. Obuchi ◽

...

Keyword(s):

Computed Tomography ◽

Carotid Artery ◽

Contrast Material ◽

Carotid Bifurcation ◽

Injection Rate ◽

Multidetector Row Computed Tomography ◽

Time To Peak ◽

Scan Speed ◽

Group A ◽

Group B

Background: Although fast acquisition of multidetector-row computed tomography (MDCT) can make it possible to acquire sufficient early vascular enhancement using small volumes and high concentrations of contrast material (CM), there are still some problems with nephrotoxicity and costs related to CM. Purpose: To compare the qualitative and quantitative performance in cervicocranial CT angiography (CTA) using two different iodine volumes and concentrations of CM. Material and Methods: CTA ranging from the aortic arch (AA) to distal to the circle of Willis (cW) was performed on a 32-MDCT system. Fifty-eight patients were randomly divided into two groups: group A (29 patients) received 60 ml of 300 mg I/ml CM, and group B (the other 29 patients) received 40 ml of 370 mg I/ml CM. Time to peak arterial enhancement at cW (Tc) was calculated. As scan speed was 96.9 mm/s and injection rate was 4.0 ml/s, scanning delay was individually decided according to Tc and scan duration between AA and cW. Arterial attenuation along the z-axis at eight points in the carotid-cerebral artery and venous attenuation of the internal jugular vein (IJV) at carotid bifurcation were measured. Mean attenuation values were then quantitatively analyzed. Postprocessing images were qualitatively assessed. Results: Arterial attenuation profiles revealed maximum attenuation at the distal common carotid artery in both groups. Although there were no significant differences in mean arterial attenuation in group A versus group B (402±70 HU vs. 407±67 HU; P=0.78), venous attenuation of the IJV was lower in group B than in group A (114±57 HU vs. 224±81 HU; P<0.001). Although arterial images demonstrated no difference qualitatively between the two groups, the venous contamination of IVC was less prominent in group B. Conclusion: Although a different amount of CM was administered in both groups, quantitative and qualitative arterial images did not show significant differences between the two groups.

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