CT Workstation Research Articles

Morphometric Evaluation of Foramen Magnum and its Shape Variations using Computed Tomographic Images of Normal Adults

Background and aims Skull morphology plays a key role in determining gender in medico-legal cases. Computed Tomography CT measurements of foramen magnum are useful in estimating gender. In this study sagittal diameter transverse diameter and area of foramen magnum were correlated. Also different variations in the shape of foramen magnum were evaluated using computed tomography.Methods This study was conducted using CT Brain Scan images of individuals belonging to both the genders in the age group of 18 to 85 years. Morphometry of foramen magnum sagittal diameter transverse diameter area of foramen magnum measurements and different shapes of foramen magnum were estimated on CT images using a 3D program on the CT workstation and were correlated against gender.Result In this study sagittal diameter of foramen magnum was 33.5 plusmn 2.9 mm among males and 31.4 plusmn 3.2 mm among females. Transverse diameter was found to be 29.1 plusmn 3.3 mm in males and 26.7plusmn3.7 mm in females. Area of foramen magnum was measured to be 642 plusmn 94.2 mm in males and 559.9 plusmn 115.5 mm in females. All the variables showed significant higher values in males than in females.Conclusion Based on the findings of this study conducted using CT scan images the foramen magnums diameter and area demonstrated a high degree of precision in gender identification. The results of this study could be used to identify human remains if other identifying techniques were unsuccessful.

Preoperative evaluation of vascular anatomy of right colic vessels using enhanced computed tomographic colonography.

The purpose of this study is to define the blood vessels from a surgical perspective and show the frequency of vascular anatomical anomalies as well as the positional relationship with the surrounding organs, including the number of jejunal veins that cross the dissection area in our series. From January 2016 to December 2018, 126 patients who received ileocecal resection or right hemicolectomy for colonic cancer in our institution were retrospectively analyzed by preoperative enhanced computed tomographic colonography images that were obtained using an 80-detector row CT scanner and workstation. The ileocolic artery/vein, right colic artery/vein and middle colic artery/vein were defined as the vessels that flow directly from or into the superior mesenteric artery/vein. All colic veins that flowed into the gastro-colic trunk were defined as accessory right colic veins. The accessory right colonic vein existed more than two in 62.6% of cases. In 11 cases (8.9%), the inflow point of the ileocecal vein was on the ventral side of the pancreas. There was one jejunal vein that straddled the dissection area in 31% and two in 6.3%. This study elucidated the vascular anatomy and positional relationship with surrounding organs that is required in central vascular ligation during complete mesocolic excision for right sided colon cancer.

Clinical Application of Quantitative CT Technique in Assessing Liver Fat Content in Patients with Schizophrenia.

This paper investigates the clinical application value of quantitative CT (QCT) technique in evaluating liver fat content in patients with schizophrenia. 457 patients with schizophrenia underwent abdominal CT and QCT scans. QCT postprocessing software (QCT Pro version 6.1) measures the percentage of liver fat content in all patients and calculates the average value. Then, the CT workstation displays the corresponding liver/spleen CT value ratio. SPSS 25.0 software is used for statistical analysis of data, and the correlation coefficient between the mean liver fat content. The ratio of liver/spleen CT values is calculated and the consistency between the results is compared. The ROC curve is used to define the cutoff value of the target and evaluate its diagnostic efficiency. There is a high negative correlation between the mean liver fat content and the ratio of liver/spleen CT value in all schizophrenia patients (r = −0.935, P < 0.05). The identification rate of patients with mild fatty liver by QCT technology is 4 times higher than that of the liver and spleen CT value ratio (50.98% Vs 12.47%). Taking the ratio of the liver to the spleen as the standard, the ROC curve of the liver fat content in QCT is drawn, the cutoff values of the mean liver fat content of the normal liver and mild fatty liver and mild and moderate fatty liver were 9.35% and 19.4%, respectively. Comparing this result with the results obtained by the existing QCT for the fatty liver diagnosis and grading standard value (American standard) shows that there is a difference of about 5% between the two. Compared with the semiquantitative liver/spleen ratio, QCT technology can quantify the liver fat content. Given the particularity of patients with schizophrenia, QCT can be used as an important test for identifying early fatty liver and assessing the severity of fatty liver.

Quantitative Analysis of Residual COVID-19 Lung CT Features: Consistency among Two Commercial Software.

Objective: To investigate two commercial software and their efficacy in the assessment of chest CT sequelae in patients affected by COVID-19 pneumonia, comparing the consistency of tools. Materials and Methods: Included in the study group were 120 COVID-19 patients (56 women and 104 men; 61 years of median age; range: 21–93 years) who underwent chest CT examinations at discharge between 5 March 2020 and 15 March 2021 and again at a follow-up time (3 months; range 30–237 days). A qualitative assessment by expert radiologists in the infectious disease field (experience of at least 5 years) was performed, and a quantitative evaluation using thoracic VCAR software (GE Healthcare, Chicago, Illinois, United States) and a pneumonia module of ANKE ASG-340 CT workstation (HTS Med & Anke, Naples, Italy) was performed. The qualitative evaluation included the presence of ground glass opacities (GGOs) consolidation, interlobular septal thickening, fibrotic-like changes (reticular pattern and/or honeycombing), bronchiectasis, air bronchogram, bronchial wall thickening, pulmonary nodules surrounded by GGOs, pleural and pericardial effusion, lymphadenopathy, and emphysema. A quantitative evaluation included the measurements of GGOs, consolidations, emphysema, residual healthy parenchyma, and total lung volumes for the right and left lung. A chi-square test and non-parametric test were utilized to verify the differences between groups. Correlation coefficients were used to analyze the correlation and variability among quantitative measurements by different computer tools. A receiver operating characteristic (ROC) analysis was performed. Results: The correlation coefficients showed great variability among the quantitative measurements by different tools when calculated on baseline CT scans and considering all patients. Instead, a good correlation (≥0.6) was obtained for the quantitative GGO, as well as the consolidation volumes obtained by two tools when calculated on baseline CT scans, considering the control group. An excellent correlation (≥0.75) was obtained for the quantitative residual healthy lung parenchyma volume, GGO, consolidation volumes obtained by two tools when calculated on follow-up CT scans, and for residual healthy lung parenchyma and GGO quantification when the percentage change of these volumes were calculated between a baseline and follow-up scan. The highest value of accuracy to identify patients with RT-PCR positive compared to the control group was obtained by a GGO total volume quantification by thoracic VCAR (accuracy = 0.75). Conclusions: Computer aided quantification could be an easy and feasible way to assess chest CT sequelae due to COVID-19 pneumonia; however, a great variability among measurements provided by different tools should be considered.

Changing of pulmonary artery diameter in accordance with severity of COVID-19 (assessment based on non-contrast computer tomography)

BACKGROUND: Computed tomography is the method of choice for assessing the volume of lung damage in viral pneumonia, including those associated with COVID-19. In addition, computed tomography can determine the main vessels size of the thorax. This allowed us to analyze the relationship between the severity of COVID-19 and the changes in the diameters of the pulmonary artery (PA) and ascending aorta (Ao). Dilation of the PA is a sign of pulmonary hypertension. The study of these patterns may be of clinical significance in determining the treatment tactics and prognosis of the course of COVID-19 disease.&#x0D; AIM: To evaluate the relationship between PA diameter and the severity of the COVID-19 course in patients of different ages.&#x0D; MATERIALS AND METHODS: This study is a single-centered, cross-section, continuous, uncontrolled study performed on a group of patients (n=511, 267 men, median 59 years, IQR 49.065.0, ages 3184 years) who were treated in a temporary hospital to treat patient with COVID-19. During hospitalization all patients were examined by CT scan of the chest. All studies were carried out using a mobile CT scan system Airo TruCT (Stryker, USA). The degree of damage to the lung tissue was assessed using the CT volume scale 14. Measurement of the LA and Ao diameters was carried out using standard instruments of the radiologists CT workstation perpendicular to the long axis of the vessel.&#x0D; RESULTS: The following statistically significant regularities were obtained: the detection of a dilated pulmonary artery (PA) and an increased PA/Ao ratio correlated to an increase in the degree of lung damage in COVID-19 (Kruskal-Wallis test, K-W p 0.001; median test, MT p 0.001), the diameter of the ascending aorta (Ao) significantly increases with the patients age (K-W p 0.001; MT p 0.001). An insignificant correlation between an increase in the diameter of the pulmonary artery (PA) and the patients age (K-W p=0.094; MT p=0.311) and an insignificant correlation between detection of a change in aortic (Ao) diameter and the degree of lung damage (K-W p=0.061; MT p=0.165) were shown. In groups with a severe course of the disease and a large volume of lung lesions (CT-3 and CT-4), a significantly greater number of patients with signs of pulmonary hypertension (detection of the dilated pulmonary artery: 29 mm and more) was shown for all age groups.&#x0D; CONCLUSION: The study showed that PA dilatation and increased PA/Ao diameter ratio were significantly associated with increased pulmonary lesion volume in COVID-19 in all age groups.

Abdominal CT radiation dose reduction at Siriraj Hospital (Phase II)

Objective: To compare radiation dose, radiologists’ satisfaction, and image noise between the standard dose abdominal CT currently performed at our hospital and the new automatic tube current modulation (ATCM) low dose abdominal CT, using various parameters (0%, 10%, 20%, and 30%) of the Adaptive Statistical Iterative Reconstruction (ASiR). Materials and Methods: We prospectively performed the ATCM low dose abdominal CT in 111 participants who had prior standard dose CT for comparison. The ATCM low dose CT images were post processed with 4 parameters (0%, 10%, 20% and 30%) of ASiR on a CT workstation. The volume CT dose index (CTDIvol) of the ATCM low dose and the standard dose CT were compared. Four experienced abdominal radiologists independently assessed the quality of the ATCM low dose CT with the aforementioned ASiR parameters using a 5-point-scale satisfaction score (1 = unacceptable, 2 = poor, 3 = average, 4 = good, and 5 = excellent image quality) by using the prior standard dose CT as a reference of an excellent image quality (5). Each reader selected the preferred ASiR parameter for each participant. The image noise of the liver and the aorta in all 5 techniques (1 prior standard dose and 4 current ATCM low dose techniques) was measured. The correlation between the image quality vs the participants’ body mass index (BMI) and waist circumferences were analyzed. Results: The mean CTDIvol of the ATCM low dose CT was significantly lower than of the standard dose CT (7.29 ± 0.20 vs 11.28 ± 0.23 mGy, p&lt;0.001). The mean satisfaction score for the ATCM low dose CT with 0%, 10%, 20% and 30% ASiR were 4.14, 4.16, 4.17, and 4.26, respectively with the ranges of 3 to 5 in all techniques. The preferred ASiR parameters of each participant randomly selected by each reader were varied, depending on the readers’ opinions. The mean image noise of the aorta on the standard dose CT and the ATCM low dose CT with 0%, 10%, 20%, and 30% ASiR was 30.69, 36.60, 34.05, 31.43, and 29.09, respectively, while the mean image noise of the liver was 24.96, 29.90, 27.86, 25.66, and 23.68, respectively. There was a correlation between the image quality (satisfaction score and image noise) vs the participants’ BMI and waist circumferences. Conclusion: The ATCM low dose CT received acceptable radiologists’ satisfaction with significant radiation dose reduction. The increment of ASiR was helpful in reducing the image noise and had a tendency to increase the radiologists’ satisfaction score.

Quantitative Analysis of Calcium Oxide in the In Vivo Human Organs

Back Ground and PurposeWhen Ca2+ reacts with O2−, CaO is synthesized. If we can detect in vivo CaO in the human body, we will be able to investigate one of the pathogenesis of calcium metabolism. CT values can be assigned to the objects. The objects are assigned to different optical properties along with X‐ray CT values. Volume rendering 3D images are generated from discrete samples of the volume data obtained by X‐ray CT. To make volume rendering 3D images of a specific object are created from its optimal thresholding, opacity, and brightness. When exposed to water, CaO converts to Ca(OH)□. Volume rendering technique is carried out on the CaO to Ca(OH)□ transformation and quantitative the amount of CaO/Ca(OH)□ under the defined threshold with 100% opacity, 100% brightness, and black and red color assignment. This simplified volume rendering algorithm has found ubiquitous applications in materials science and biology of CaO. We will present a clinical usage of several common diseases.Materials and MethodsTwo clinical body CT data of osteoporosis (one was medically treated, the other was non‐treated), COPD, arteriosclerosis and back pain were used. We used the thresholding trapezoid curved algorithm which was combined with the segmentation methodology. After transferring the image data to the CT workstation, the 3D CaO image based on interactive direct volume rendering was made.ResultsThe case 1 was suffered from COPD (emphysematous type), arteriosclerosis, medically treated osteoporosis, and back pain. The 3D CaO image represented that the red lesions were seen in the ribs, the bilateral pleura or/and peripheral lung fields, the bilateral erector spinae muscle, the bilateral pedicle, the right crus, and the descending aorta posterior wall. But, there was no red lesion in the thoracic vertebra. In case 2 of postmenopausal untreated osteoporosis without any disease, there were red lesions at the cortex and the fracture lesion of the vertebra and the rib cortex. Others organs showed no CaO deposited lesions.ConclusionThis simplified technique is adapted for only in vivo CaO detection in the human body, and will attribute an in vivo calcium function and metabolism in the human organs. This is because CaO was the highest CT value in the human body. In COPD, CaO activated at the peripheral lung fields. The arteriosclerotic wall deposited CaO. In the untreated postmenopausal osteoporosis, CaO activated at the cortex and the vertebral fracture. But, the treated case did not show CaO deposited at the cortex. These CaO accumulated regions will indicate that it is considered that a chemical reaction between Ca2+ and O2− or/and O− occurred. These images will implicate CaO metabolisms in the human organs. These facts show that CaO is an important role for several diseases. We think that this simplified technique of 3D CaO imaging makes a new step of etiological researches. The 3D reconstructed anatomical fusion image in Case 1. The red lesions are seen at the ribs, the bilateral pleura or/and peripheral lung fields, the bilateral erector spinae muscle, the bilateral pedicle, the right crus, and the descending aorta posterior wall. .imageThe 3D reconstructed anatomical fusion image in Case 1. The red lesions are seen at the ribs, the bilateral pleura or/and peripheral lung fields, the bilateral erector spinae muscle, the bilateral pedicle, the right crus, and the descending aorta posterior wall. . Case 2: The untreated postmenopausal osteoporosis. CaO activates at the cortex and the vertebral fracture.imageCase 2: The untreated postmenopausal osteoporosis. CaO activates at the cortex and the vertebral fracture.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Superior vena cava syndrome in the CT scanning

The study concerns a 67-year-old woman with symptoms such as swelling of the face, neck and upper limbs; bruising in the head and neck region; conjunctival hyperemia; excessive filling of the jugular veins. The CT examination was performed using the SOMATOM Definition AS (Siemens) and analyzed with SYNGO Multi-Modality CT Workstation (Siemens). The study showed a tumoral mass (67 x 91 mm) located in the right upper lobe and adjacent to the mediastinum, simultaneously invades the superior vena cava and causes it to narrow completely.

Establishment and application of three-dimensional model of deep inferior epigastric artery perforator flap based on computed tomography angiography

Objective: To explore the establishment and application of three-dimensional model of deep inferior epigastric artery perforator flap based on computed tomography angiography (CTA). Methods: Six patients with breast absence after modified radical mastectomy because of breast cancer, 5 patients with congenital absence of vagina, and 6 patients with Paget's disease of penis and scrotum were hospitalized in our unit from January 2012 to April 2017. The size of wounds after excision of the lesion or that of flaps needed for reconstruction ranged from 17 cm×5 cm to 25 cm×9 cm. Abdominal CTA was performed before the surgery, and data of CTA were sent to CT workstation to make three-dimensional model of deep inferior epigastric artery perforator flap according to shape and size of wound. The number, course, and location of deep inferior epigastric artery, vein, and their perforators, and the superficial inferior epigastric vein were observed in the above-mentioned three-dimensional model. The rectangular plane coordinate system with the umbilicus as the origin was established to locate and observe course and type of the largest deep inferior epigastric artery perforator in left and right side. Deep inferior epigastric artery perforator flaps were designed and deep inferior epigastric artery perforators etc. were marked according to three-dimensional models of the flaps before the surgery. The condition observed in three-dimensional model of the flap was compared with the clinical condition in the surgery of free transverse bilateral deep inferior epigastric artery perforator flap transplantation for breast reconstruction and longitudinal pedicled thinned unilateral deep inferior epigastric artery perforator flap transplantation for vagina reconstruction and wound repair of Paget's disease of penis or scrotum. The size of flap ranged from 17 cm×6 cm to 25 cm×10 cm. Results: Seventeen three-dimensional models of deep inferior epigastric artery perforator flaps were established, including 6 bilateral models and 11 unilateral models. Seventy-two reliable deep inferior epigastric artery perforators were observed in the three-dimensional model with 3.2±0.7 in the right and 3.1±0.8 in the left. The locations of the largest deep inferior epigastric artery perforators in the right and left were [(-3.2±1.4) cm, (-1.0±0.7) cm] and [(4.0±1.2) cm, (-1.2±1.1) cm] respectively. Fourteen largest deep inferior epigastric artery perforators coursed directly and nine coursed tortuously in the rectus muscle. Twenty-three superficial inferior epigastric veins were detected in the three-dimensional models of the flaps. The number, location, and course of deep inferior epigastric artery and vein and superficial inferior epigastric vein observed in the three-dimensional model of deep inferior epigastric artery perforator flap were in accordance with the condition observed in the surgery. Seventy reliable deep inferior epigastric artery perforators were detected in the surgery, and the other 2 perforators were unclear due to bleeding. Course of these perforators were in accordance with the condition observed in the three-dimensional model. Deep inferior epigastric artery perforator flaps of all patients survived well with no complication except that 1 patient suffered from delayed healing of wound in perineum. During follow-up of 1 to 12 months, all flaps survived with good shape and texture. Conclusions: The three-dimensional model of deep inferior epigastric artery perforator flap based on CTA can be established easily and can provide information of number, location, and course of deep inferior epigastric artery, vein, and their perforators, and superficial inferior epigastric vein to guide preoperative design and intraoperative dissection of the flap effectively.

Novel weight-based dose threshold for 18F-NaF PET-CT imaging using advanced PET-CT systems: a potential tool for reducing radiation burden.

Fluorine-18-sodium fluoride (F-NaF) PET/CT is an important tool for detecting and evaluating metastatic bone cancer. Besides traditional dose metrics, recent methods such as real-time dose mapping, dose calculation from DICOM information, and their relevance to entrance skin exposure are currently in use to reduce the radiation burden. In this study, we have analyzed the data of 1062 patients retrospectively to evaluate patterns of absorbed dose for institutional weight-based dose protocol as compared with fixed dose method guidelines of Society of Nuclear Medicine and Molecular Imaging (SNMMI). The effective dose imparted by F-NaF (internal exposure) was calculated by using coefficient 0.089 mrem/mCi (0.024 mSv/MBq) according to ICRP publication 106. To estimate the effective dose from whole-body CT scan (external exposure), volume CT dose index (mGy) and dose length product (mGy cm) were directly obtained from the display screen of CT workstation. Effective dose was calculated by multiplying DLP (mGy cm) with ICRP conversion coefficient 'k' 0.015 (mSv/mGy cm). Of the total 1062 patients, there were metastases in 44% (464), probable malignancy in 9% (96), negative findings in 40.5% (433), equivocal findings in 3% (32), and probable benignancy in 3.5% (37). All patients were injected with an institutional agreed protocol of 2.22 MBq/kg (0.06 mCi/kg). The mean injected activity for entire population came out to be 4.79±0.99 mCi. The mean effective absorbed doses were 3.37±0.70 and 5.5±1.35 mSv for F-NaF alone and CT alone, respectively. The mean cumulative effective dose of combined F-NaF PET and CT scan was calculated to be 8.8±1.8 mSv. The minimum absorbed dose for our method was as follows: 1.37 mSv for Kuwait Cancer Control Center vs. 4.44 mSv for SNMMI. Absorbed dose for maximum injected activity was as follows: 5.7 mSv for Kuwait Cancer Control Center vs. 8.88 mSv for SNMMI. Our weight-based doses were also lower when compared with minimum and maximum absorbed doses of technetium-99m-methylene diphosphonate as per SNMMI guidelines (i.e. 4.21 and 6.32 mSv, respectively). Our weight-based dose protocol showed a significant reduction in absorbed doses (i.e. 69.14% for F-NaF and 67.45% for technetium-99m-methylene diphosphonate) when compared with fixed dose method guidelines of SNMMI. It is suggested that further prospective studies may be performed in adult population, to evaluate dosimetry efficacy of F-NaF at a low dose of 0.06 mCi/kg as inferred in our current study.

A comparison of radiation dose in single and split bolus multidetector computed tomography urography

Introduction: Routine multidetector computed tomography (MDCT) urography protocols include three phase scan with single bolus contrast material injection. To reduce the radiation dose a split bolus MDCT urography technique has been introduced. Methods: Nephrographic phase in single bolus was obtained by injecting 90 ml of Ioversol (Optiray320mgI/ml) contrast at the rate of 3ml/s during the preset time of 90 second. The excretory phase was taken at the delay of 10 minutes after the contrast injection. For split bolus only two phases (unenhanced and combined) were scanned from the diaphragm to the base of the urinary bladder. The combined phase in split bolus was performed by injecting the contrast in two bolus in which 40 ml at 2ml/s was injected in the first bolus and after a delay of 9 minutes, 60 ml at a rate of 3ml/s was injected, then the scan was obtained 90 second after the second bolus. The volume CT dose index (CTDIvol) and CT dose length product (CTDLP) were assessed in CT work station. Results: The mean effective radiation dose for single bolus MDCT urography was 40.5% more than the split bolus MDCT urography. Conclusion: Split bolus MDCT urography protocol was significantly better in effective radiation dose reduction compared with the single bolus MDCT urography protocol.

The Quantitative Observation of Interbody Fusion with Local Autogenous Bone Harvested from Single Interlaminar Fenestration in PLIF

Introduction Local autogenous bone (LABORATORY) harvested from interlaminar fenestration or total facetectomy has been widely applied in interbody fusion of lumbar disc degenerative diseases (DDD) with satisfactory clinical results. However, there was lack of weight and volume observation of LABORATORY harvested from single interlaminar fenestration(SIF). The aim of this study was to quantitative observe the interbody fusion feasibility with LABORATORY harvested from SIF in PLIF. Materials and Methods 107 patients were undergone PLIF only by LABORATORY+one cage at L4/5 and/or L5S1 due to DDD. The weight and volume of LABORATORY from SIF were measured by analytical balance and 5ml disposal sterile syringe. The height of cages used intraoperative were recorded. The area of endplate (Se) and the contact area (Sc) between the cartilaginous endplate and LABORATORY +cage at every intervertebral space was measured and calculated by PACS of CT workstation. The clinical results and fusion status were estimated by JOA score and 3D-CT at 12, 18 and 24 months postoperative. Results 113 segments of 107 patients were successfully fused only by LABORATORY harvested from SIF. The weight and volume of LABORATORY from SIF showed no significant differences at different ages, genders, segments and type of DDD, and the same result exists about Se and the height of interbody space in L4/5 or L5S1 segments. The mean volume and weight of LABORATORY were 3.1ml and 3.7 g from SIF. The packing ratio (PR) of LABORATORY+one cage was 38.1%. The volume and weight to reach 30% PR needed ~2.5ml and 3.0 g LABORATORY. 94 cases (98 segments) were followed up for average 24 months postoperative. The improvement rate of JOA score was 82.5%, and the fusion rate was 92.9%. Conclusion SIF can provide enough LABORATORY for one interbody fusion in PLIF. The average volume and weight of LABORATORY from SIF were 3.1ml and 3.7 g respectively. 38% PR, including one cage, is achievable at fusion segment in present study. 2.5 ml (3.0 g) LABORATORY+one cage can perform ~30% PR.

Radiological mass casualty incident (MCI) workflow analysis: single-centre data of a mid-scale exercise.

The aim of the study was to analyse and interpret radiological mass casualty incident workflow data. In a mid-scale mass casualty incident exercise, the on-site triage assigned 12 cases to the investigated institution (11 included in the study). Two out of five institutional multislice-CT-scanners were used and the whole CT workflow and radiological service process chain were simulated as close to realistic as possible. The respective time intervals for reaching defined milestones were measured. The average CT in-room time, i.e. from entering to leaving the CT room was 9.43 min [(standard deviation) SD: 2.27 min; 95% (confidence interval) CI: 7.90-10.95 min]. Time spent on CT table was 6.75 min (SD: 1.67; CI: 5.63-7.87), and the pure scan time was 4.22 min (SD: 0.64; CI: 3.79-4.65). The first images after entering the CT room were available at a dedicated CT workstation after 5.85 min (SD: 2.20; CI: 4.37-7.32) and institution wide via picture archiving system (PACS) after 7.85 min (SD: 1.27; CI: 7.00-8.71). However, the PACS archiving process, that is, transfer of standard reconstruction set of CT images into the PACS was finished after 20.85 min (SD: 2.97; CI: 18.85-22.84). Up to six patients may be served per hour and per CT scanner by using a standard whole body CT polytrauma protocol. Dedicated CT triage protocols may even increase this number. The time portion until images were available at end points was relatively long. A solution has to be developed in order to avoid scenarios of patients being faster at end points than their images.

Morphometric and radiological assessments of dimensions of Axis in dry vertebrae: A study in Indian population.

Background:The technique of intralaminar screw placement for achieving axis (C2) fixation has been recently described. The purpose of the study was to provide the morphometric and radiological measurements in Indian population and to determine the feasibility of safe translaminar screw placement in this population. To the best of our knowledge there is no study (cadaveric or radiological) done in Indian population to detect suitability of axis bone for laminar screw fixation.Material and Methods:38 dry axis vertebrae from adult South Indian population were subjected to morphometric measurement and CT scan analysis. Height of posterior arch, midlaminar width(bilateral) in upper 1/3rd, middle 1/3rd and lower 1/3rd were measured using high precision Vernier Calipers. Each vertebra was subjected to a spiral CT scan (Philips brilliance 16 slice) thin 0.5 mm slices were taken and reconstruction was done in coronal and sagittal plane. Analysis was done on a CT work station. Using axial slices, sagittal cuts were reconstructed in plane perpendicular to the lamina at the mid laminar point and upper-middle and lower 1/3rd width of the lamina measured. Height of the posterior arch was measured in the sagittal plane. Intralaminar angle was measured bilaterally.Results:Middle 1/3rd lamina was the thickest portion (mean 5.17 mm +/- 1.42 mm). A total of 32 (84.2%) specimen were having midlaminar width in both lamina greater than 4 mm, however only 27 (71%) out of them had spinous process more than 9 mm. CT scan measurement in middle and lower 1/3rd lamina was found to be strongly correlated with the direct measurement.Conclusion:There is high variability in the thickness of the C2 lamina. As compared to western population, the axis bones used in the present study had smaller profiles. Hence the safety margin for translaminar screw insertion is low.

Novel Application of Postmortem CT Angiography for Evaluation of the Intracranial Vascular Anatomy in Cadaver Heads.

Postmortem CT angiography is a common procedure used to visualize the entire human vasculature. For visualization of a specific organ's vascular anatomy, casting is the preferred method. Because of the permanent and damaging nature of casting, the organ cannot be further used as an experimental model after angiography. Therefore, there is a need for a minimally traumatic method to visualize organ-specific vascular anatomy. The purpose of this study was to develop and evaluate a contrast enhancement technique that is capable of visualizing the intracranial vascular anatomy while preserving the anatomic integrity in cadaver heads. Seven human heads were used in this study. Heads were prepared by cannulating the vertebral and internal carotid arteries. Contrast agent was injected as a mixture of tap water, polyethylene glycol 600, and an iodinated contrast agent. Postmortem imaging was executed on a 64-MDCT scanner. Primary image review and 3D reconstruction were performed on a CT workstation. Clear visualization of the major cerebral arteries and smaller intracranial branches was achieved. Adequate visualization was obtained for both the anterior and posterior intracranial circulation. The minimally traumatic angiography method preserved the vascular integrity of the cadaver heads. A novel application of postmortem CT angiography is presented here. The technique can be used for radiologic evaluation of the intracranial circulation in cadaver heads. After CT angiography, the specimen can be used for further experimental or laboratory testing and teaching purposes.

Preoperative Prediction of Ki-67 Labeling Index By Three-dimensional CT Image Parameters for Differential Diagnosis Of Ground-Glass Opacity (GGO).

The aim of this study was to predict Ki-67 labeling index (LI) preoperatively by three-dimensional (3D) CT image parameters for pathologic assessment of GGO nodules. Diameter, total volume (TV), the maximum CT number (MAX), average CT number (AVG) and standard deviation of CT number within the whole GGO nodule (STD) were measured by 3D CT workstation. By detection of immunohistochemistry and Image Software Pro Plus 6.0, different Ki-67 LI were measured and statistically analyzed among preinvasive adenocarcinoma (PIA), minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC). Receiver operating characteristic (ROC) curve, Spearman correlation analysis and multiple linear regression analysis with cross-validation were performed to further research a quantitative correlation between Ki-67 labeling index and radiological parameters. Diameter, TV, MAX, AVG and STD increased along with PIA, MIA and IAC significantly and consecutively. In the multiple linear regression model by a stepwise way, we obtained an equation: prediction of Ki-67 LI=0.022*STD+0.001* TV+2.137 (R=0.595, R’s square=0.354, p<0.001), which can predict Ki-67 LI as a proliferative marker preoperatively. Diameter, TV, MAX, AVG and STD could discriminate pathologic categories of GGO nodules significantly. Ki-67 LI of early lung adenocarcinoma presenting GGO can be predicted by radiologic parameters based on 3D CT for differential diagnosis.

The usefulness of stone density and patient stoutness in predicting extracorporeal shock wave efficiency: Results in a North African ethnic group.

We determine the role of stone density and skin-to-stone distance (SSD) by non-contrast computed tomography of the kidneys, ureters and bladder (CT-KUB) in predicting the success of extracorporeal shock wave lithotripsy (ESWL). We evaluated 89 patients who received ESWL for renal and upper ureteric calculi measuring 5 to 20 mm, over a 12-month period. The mean stone density in Hounsfield units (HU) and mean SSD in mm was determined on pre-treatment CT-KUB at the CT workstation. ESWL was successful if post-treatment residual stone fragments were ≤3 mm. ESWL success was observed in 68.5% of patients. Mean stone densities were 505 ± 153 and 803 ± 93 HU in the ESWL successful and failure groups, respectively (p < 0.001, student's t-test). The mean SSD were 10.6 ± 2.0 and 11.2 ± 2.6 cm in ESWL successful and failure groups, respectively; this was not statistically significant. This study shows that stone density can help to predict the outcome of ESWL. We propose that stone density <500 HU are highly likely to result in successful ESWL. Conversely, stone densities >800 HU are less likely to be successful.

The footprint of femoral insertion of anterior cruciate ligament three-dimensionally reconstructed by dual-source CT

Objective To measure the double-bundle footprints of the anterior cruciate ligament (ACL) three-dimensionally reconstructed by dual-source three-dimensional computed tomography (DSCT) so as to provide parameters for anatomic double-bundle ACL reconstruction in clinic.Methods This study enrolled 55 healthy volunteers,32 men and 23 women,20 to 50 years of age (average,28 years).One hundred and ten knees were scanned and processed with 64-slice spiral CT workstation (GE,Volume Share2-AW 4.4 version).The lateral wall of the intercondylar notch and the ACL femoral footprint were reconstructed three-dimensionally.The angle,length and width of the footprint,the distance between the double-bundle centers (DDBC) (anteromedial bundle and posterolateral bundle),and the distance from the footprint edge to the margin of the articular cartilage were measured.Results In this serial,the footprint angle averaged 6.8° ± 4.6°,the long footprint axis 16.8 ± 1.7 mm,the short footprint axis 7.5 ± 1.4 mm,DPCM 1.9 ± 1.0 mm,DDCM 1.5 ± 1.3 mm,and DDBC 8.0 ± 1.0 mm.There were no significant differences concerning footprint angle,long footprint axis,short footprint axis,DPCM,DDCM and DDBC between the left and the right knees in men and in women ( P ＞ 0.05) except concerning DPCM between the left and the right knees in women ( P ＜ 0.05).There were no significant differences concerning footprint angle and short footprint axis between men and women (P＞ 0.05),but there were significant differences concerning long footprint axis,DPCM,DDCM and DDBC between men and women ( P ＜ 0.05).Conclusions Measurements of femoral ACL footprints by DSCT reconstruction in normal population are reliable and representative.The footprint angle,DDBC and the distance from the footprint edge to the margin of the articular cartilage vary from individual to individual. Key words: Anterior cruciate ligament; Femur; Tomography; spiral computed

The relationship between aortic aneurysm sac thrombus volume on coagulation, fibrinolysis and platelet activity

AimAbdominal aortic aneurysm (AAA) is associated with chronic mural inflammation and a pro-thrombotic diathesis. It has been suggested that both may be related to biologically active intra-sac thrombus. The aim of this study was to examine the relationship between thrombin generation, fibrinolysis, platelet activity and AAA sac thrombus volume. Methods30 patients (29 men) of median (IQR) age 75 (71–82) years with an infra-renal AAA >5.5cm in antero-posterior diameter were prospectively studied. AAA, lumen and thrombus volumes were calculated using a CT workstation (Vitrea). Plasma thrombin-antithrombin (TAT), plasminogen activator inhibitor (PAI)-1, and soluble (s) P-selectin were measured as biomarkers of coagulation, fibrinolysis and platelet activity, respectively ResultsMedian (IQR) AAA total, lumen and thrombus volumes were 188 (147–247) cm3, 80 (54.3-107) cm3 and 97.6 (63–127) cm3 respectively.TAT levels were significantly higher (median, QR, 7.15 [4.7-31.3] μg/L, p=<0.001) and sP-selectin levels significantly lower (median, IQR, 80.5 [68–128] ng/ml, p=<0.0001) than the normal range. PAI-1 levels (median, IQR, 20.9 [8.4-50.7] ng/ml) were normal. There was no correlation between AAA thrombus volume and PAI-1 (r=−0.25, p=0.47), sP-Selectin (r=0.26, p=0.43) or TAT plasma levels (r=−0.21, p=0.54). ConclusionThe present study confirms that patients with AAA demonstrate haemostatic derangement, but the extent of the haemostatic derangement does not correlate with AAA sac thrombus volume.

Three-dimensional reconstruction of the femoral footprint of anterior cruciate ligment by dual-source CT

Objective To reconstruct three-dimensional femoral footprint of the anterior cruciate ligament (ACL) by dual-source CT (DSCT),which can provide a novel positioning system particularly applicable in the anatomic ACL reconstruction under arthroscopy. Methods DSCT scanning was performed for the bilateral knees of 30 healthy volunteers.Three-dimensional reconstruction of the lateral wall of the intercondylar notch was done with 64-slice spiral CT workstation (GE,Volume Share2-AW 4.4 version).Double-bundle footprints of the ACL femoral insertions were identified, outlined and marked on the three-dimensional models.The over-the-top junction of the distal femur and the trochlea of femoral lateral condyle was dotted as a reference point O.The femoral footprint long and short axes,the footprint angle between the line passing through 2 centers of anteromedial and posterolateral bundles and the femoral shaft,the distance between 2 bundle centers,the shortest distance from the footprint edge to the distal femoral cartilage,and the shortest distance from the footprint edge to the posterior margin of the femoral cartilage were measured on the models with a standardized scale. Results All the ACL femoral footprints were successfully reconstructed by DSCT in the 60 knee joints.They were relatively protruding,plain,irregular in shape but identical in grey scale,distinct areas on the image. On the three-dimensional models of femoral lateral condyle,a 3-point-2-angle positioning system applicable in arthroscopic anatomic ACL reconstruction was successfully established and used to define and describe the double-bundle insertions of ACL.The mean long and short axes of ACL femoral footprint were respectively 16.5 ± 1.8 mm and 8.0 ± 1.3 mm; the mean ACL footprint angle was 8.3° ±4.9°; the mean distance between 2 bundle centers was 7.8 ± 1.0 mm; the mean shortest distance from the footprint edge to the distal femoral cartilage was 1.6 ± 1.5 mm; the mean shortest distance from the footprint edge to the posterior margin of the femoral cartilage was 1.7 ± 0.9 mm. Conclusions Three-dimensional ACL femoral footprints can be clearly reconstructed with DSCT.Natural ACL femoral footprints vary from person to person,which indicates a need of individualized reconstruction in order to restore the anatomy in maximum.The 3-point-2-angle positioning system we have developed is just suitable for arthroscopic ACL reconstruction. Key words: Anterior cruciate ligament; Femur; Tomography, spiral computed