Value of 3D-Volume Rendering in the Assessment of Coronary Arteries with Retrospectively Ecg-Gated Multislice Spiral CT

International Nuclear Information System (INIS)

Mahnken, A.H.; Wildberger, J.E.; Dedden, K.; Schmitz-Rode, T.; Guenther, R.W.; Sinha, A.M.; Hoffmann, R.; Stanzel, S.

2003-01-01

Purpose: To assess the diagnostic value and measurement precision of 3D volume rendering technique (3D-VRT) from retrospectively ECG-gated multislice spiral CT (MSCT) data sets for imaging of the coronary arteries. Material and Methods: In 35 patients, retrospectively ECG-gated MSCT of the heart using a four detector row MSCT scanner with a standardized examination protocol was performed as well as quantitative X-ray coronary angiography (QCA). The MSCT data was assessed on segmental basis using 3D-VRT exclusively. The coronary artery diameters were measured at the origin of each main coronary branch and 1 cm, 3 cm and 5 cm distally. The minimum, maximum and mean diameters were determined from MSCT angiography and compared to QCA. Results: A total of 353 of 525 (67.2%) coronary artery segments were assessable by MSCT angiography. The proximal segments were more often assessable when compared to the distal segments. Stenoses were detected with a sensitivity of 82.6% and a specificity of 92.8%. According to the Bland-Altman method the mean differences between QCA and MSCT ranged from 0.55 to 1.07 mm with limits of agreement from 2.2 mm to 2.7 mm. Conclusion: When compared to QCA, the ability of 3D-VRT to quantitatively assess coronary artery diameters and coronary artery stenoses is insufficient for clinical purposes

Study of the usefulness of large intestine screening inspections using multi-slice CT (MSCT)

International Nuclear Information System (INIS)

Yamasaki, Michihiro; Nonogaki, Hidehiko; Hara, Koji; Naruse, Yutaka; Hara, Hiroto; Suematsu, Seiji; Yanase, Tadahiko; Otou, Taiji

2005-01-01

CT-colonography (CT-C), a new diagnostic imaging technique for cancer of the large intestine-which is increasing rapidly owing to westernized eating habits-has advanced from the developmental stage to the stage of practical application, thanks to progress in MSCT and workstation development. Therefore, based on the results of CT-C application using 16 lines of MSCT to a screening test, we reviewed the usefulness of CT-C in our clinic. We supplemented defective depiction, and found that change of position was effective for virtual image exclusion. We consider that CT-C can support diagnosis if the target of screening tests is a polypoid lesion of more than 6 mm. In addition, it is expected that the number of examinations performed during office visits will increase because of the decreased invasiveness of the procedure, its lack of pain, and its ability to provide early lesion detection. (author)

Evaluation of the nutcracker syndrome using multi-slice spiral CT

International Nuclear Information System (INIS)

Shi Heshui; Fan Yanqing; Han Ping; Zhou Chengkai; Zhao Long; Wu Hongying; Yu Qun; Liu Yonghua

2007-01-01

Objective: To evaluate the ability of multi-slice spiral CT (MSCT) in diagnosing nutcracker syndrome(NCS). Methods: MSCT angiography (MSCTA) or contrast enhanced CT data of 16 patients clinically diagnosed as NCS( patient group) and 80 subjects with nomal kidneys and renal vessels (control group ) were retrospectively reviewed. The anatomy, course and relationship to the adjacent structure of left renal vein (LRV) and its branches were observed. The angle (a) between SMA and the abdominal aorta (AA), the distance (d) between SMA and AA at the level of LRV passing through, the cross areas of LRV through the angle (s1) and at the largest diameter near the renal hilar (s2) were measured and the ratio(q) of s2 to sl was calculated. Results: All LRVs were compressed and showed dilated, 7 of them with the genesial gland vein enlargement. The causes of the LRV narrowing and obstruction were small angle (a) in 14 patients and abnormal path of LRV posterior to AA in 2 cases. The value of a,d,s1,s2 and q in the patient group and the control group were: (21±4) degree, (0.53±0.11) cm, (0.28±0.06) cm 2 , (1.42±0.48) cm 2 , 5.26 and (52±24) degree, (1.39±0.70) cm, (0.81±0.32) cm 2 , (1.21±0.35) cm 2 , 1.52, respectively. The differences were significant between the two groups (P< 0.05). Conclusion: The appearance and its path of the LRV could be well delineated on the MSCT, allowing a accurate evaluation of the LRV narrowing non-invasively. (authors)

Imaging of head and neck tumors -- methods: CT, spiral-CT, multislice-spiral-CT

International Nuclear Information System (INIS)

Baum, Ulrich; Greess, Holger; Lell, Michael; Noemayr, Anton; Lenz, Martin

2000-01-01

Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the

Multi-slice spiral CT coronary angiography: influence of heart rate and reconstruction window on image quality

International Nuclear Information System (INIS)

Mao Dingbiao; Hua Yanqing; Wang Mingpeng; Zhang Guozhen; Wu Weilan; Hu Fei; Ge Xiaojun; Ding Qiyong

2004-01-01

Objective: To evaluate the influence of heart rate and reconstruction window on image quality of multi-slice spiral CT coronary angiography. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 80 healthy cases. Results: Four coronary (RCA, LM, LAD, LCX) segments were analyzed in each patient with regard to image quality. 82.1% (46/56) of the coronary segments were sufficient for analysis in patients with heart rate ≤60 bpm, 63.4% (104/164) with 61-70 bpm, 41.2%(28/68) with 71-80 bpm, and 31.2%(10/32) with>80 bpm, respectively. The left anterior descending artery, left circumflex artery, and the right coronary artery were best visualized when the reconstruction window was 60%-70%, 50%-60%, and 50%-70%, respectively. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate and reconstruction window

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

Science.gov (United States)

Wenz, Holger; Maros, Máté E; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

2015-01-01

To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (pspiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

Basic examination of in-plane spatial resolution in multi-slice CT

International Nuclear Information System (INIS)

Hara, Takanori; Kato, Hideki; Akiyama, Mitsutoshi; Murata, Katsutoshi

2002-01-01

In computed tomography (single-slice spiral CT, conventional CT), in-plane (x-y plane) spatial resolution is consistently identified as depending on the detector density of the in-plane (x-y plane). However, we considered that the in-plane (x-y plane) spatial resolution of multi-slice CT (MSCT) was influenced by an error in the detector's sensitivity to the Z-axis and by the frequency of use of direct row data and complementary row data when the image of spiral pitches (SP) was reconstructed. Our goal in this experiment was to analyze the relationship of the in-plane (x-y plane) spatial resolution of an asymmetric-type detector in MSCT to SP, tube current, and rotation time. By employing a tungsten wire phantom of 0.2 mm in diameter, we examined modulation transfer functions (MTF) by point-spread functions (PSF) of CT-images. Next, using the mean-square-root bandwidth theory, we analyzed the MTF of wire phantoms. The analysis of in-plane (x-y plane) spatial resolution revealed that various tube currents had no effect on the value of the mean-square-root bandwidth. However, rotation time and high spiral pitch did have an effect on mean-square-root bandwidth. Considering the results mentioned above, spiral pitch (z-axis reconstruction algorithm) had a slight effect on in-plane (x-y plane) spatial resolution of asymmetric-type detectors in MSCT. Accordingly, we proposed a new general view of VDDz (view/mm) in MSCT that considered view data density on the Z-axis according to spiral pitch (mm/rotation), rotation time (view/rotation), and slice collimation. (author)

The value of multislice spiral CT in the pre-operative diagnosis of cleft palate

International Nuclear Information System (INIS)

Tang Guangxi; Sun Lianfen; Zhang Xiaolin; Yu Chengxin; Lu Ji; Wang Xiaopeng; Li Liya; Yang Cheng; Wang Jun; Tian Yiqing

2004-01-01

Objective: To evaluate the practical value of multislice spiral CT (MSCT) in the preoperative diagnosis of cleft palate. Methods: Twenty patients with cleft palate were examined by using thin-slice (1.25 mm/4i) axial MSCT scanning and CT virtual endoscope (CTVE) imaging before and after operations. The cleft of each lesion was measured in the primary axial images. Results: Of the 20 cases, soft-and-hard cleft palate (grade II) was detected in 10 cases, with the clefts of soft palate between 1.5 cm and 2.2 cm, and the clefts of soft-and-hard palate between 1.2 cm and 2.0 cm. The right utter cleft palates were found in 3 cases with the clefts of soft palate between 2.0 cm and 2.5 cm, the clefts of soft-and-hard palate between 2.0 cm and 2.4 cm, and the clefts of hard palate between 1.8 cm and 2.2 cm. The left utter cleft palates (grade III) were found in 5 cases with the clefts of soft palate between 1.2 cm and 1.8 cm, the clefts of soft-and-hard palate between 0.9 cm and 2.0 cm, and the clefts of hard palate between 0.9 cm and 1.8 cm. The bilateral utter cleft palates (grade III) were detected in 2 cases with the clefts of soft palate between 2.1 cm and 2.3 cm, the clefts of soft-and-hard palate between 1.8 cm and 2.0 cm, and the clefts of hard palate between 1.9 cm and 2.3 cm. Conclusion: MSCT could excellently display the shape of all lesions before operation, especially the splitting degree of hard cleft palates in the axial images. Accurate measurements could be done for the cleft of different lesions in MSCT images. CTVE could clearly and directly show the shape of the lesion's interior surface. The pre-operative and post-operative images of each case could be perfectly compared by the combination of MSCT and CTVE

Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

International Nuclear Information System (INIS)

Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

2007-01-01

Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

Triple-phase enhanced MSCT in evaluating solitary pulmonary nodules

International Nuclear Information System (INIS)

Zhang Jin'e; Zhao Zhenjun; Liang Changhong; He Hui; Zhang Jia; Ru Guangteng

2005-01-01

Objective: An evaluation of the triple-phase enhanced MSCT in the assessment of solitary pulmonary nodules (SPN). Methods: Prospective study was made on 102 SPN using triple-phase enhanced MSCT, and the net elevation of the CT value of nodules as well as the neoplastic blood vessels were assessed. In total 102 patients were enrolled, including 63 males and 39 females, aged from 17 to 87 years (57.2 years in average). The nodules sized from 2.1 to 4.0 cm (3.3cm in average). Pulmonary carcinoma was proved in 71 cases and benign SPN in 31 cases(including 11 inflammatory pseudo tumors, 6 tuberculosis, 3 inflammatory granulomas, 3 lesions of acute nonspecific inflammation, 3 hamartomas, 3 mycosis and 2 abscesses). The spiral scan was performed on an 8-row detector spiral CT (GE/light speed Qx/I Extra) with 5mm/4 slices. The scan time was 1 second per circle. The 5mm sliced imaging was done for CT value measurement and 1.25mm sliced imaging was for MPR(multiplanar reconstruction) or VR(volume rendering), 20ml Ultravist(300 mg/I) was administered at first at a rate of 4ml/s via forearm superficial vein by a power injector. The peak CT values in pulmonary artery and aorta were to determine the delay time for the acquisition in pulmonary phase and aortal phase. Then Ultravist in a volume of lml/ body kilogram was injected, followed by 50 ml of sodium chloride. Delay phase was 3 minutes. Results: The differences of net increased CT value in three phases were statistically significant respectively between lung cancer and benign nodules (F=30.668, 4.495 and 56.141, respectively, P=0.000, 0.036 and 0. 000, respectively). When the net increased CT value≥20 HU was set as a diagnostic threshold, the sensitivity, specificity, positive predict value, negative predict value and veracity were 93%, 29%, 75%, 64.3% and 73.5%. When net increased CT value ≥20 HU in aortal phase while net increased CT value < 20 HU in pulmonary phase was set as a di- agnostic threshold, those values

A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

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Liang Xin, E-mail: Xin.Liang@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); College of Stomatology, Dalian Medical University (China); Jacobs, Reinhilde, E-mail: Reinhilde.Jacobs@uz.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Hassan, Bassam, E-mail: b.hassan@acta.n [Department of Oral Radiology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); Li Limin, E-mail: Limin.Li@uz.kuleuven.b [Department of Paediatric Dentistry and Special Dental Care, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Pauwels, Ruben, E-mail: Ruben.Pauwels@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Corpas, Livia, E-mail: LiviaCorpas@gmail.co [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Souza, Paulo Couto, E-mail: Paulo.CoutoSouza@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Martens, Wendy, E-mail: wendy.martens@uhasselt.b [Department of Basic Medical Sciences, Faculty of Medicine, University of Hasselt, Diepenbeek (Belgium); Shahbazian, Maryam, E-mail: Maryam.Shahbazian@student.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Alonso, Arie, E-mail: ariel.alonso@uhasselt.b [Department of Biostatistics and Statistical Bioinformatics, Universiteit Hasselt (Belgium)

2010-08-15

Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

International Nuclear Information System (INIS)

Liang Xin; Jacobs, Reinhilde; Hassan, Bassam; Li Limin; Pauwels, Ruben; Corpas, Livia; Souza, Paulo Couto; Martens, Wendy; Shahbazian, Maryam; Alonso, Arie

2010-01-01

Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

Primary research on direct multi-slice spiral CT venography in inferior vena cava

International Nuclear Information System (INIS)

Gong Peiyou; Liu Fengli; Ma Xianying; Zhao Li; Wang Liping; Li Xuehua; Li Jian

2010-01-01

Objective: To investigate the superiority of direct multi-slice spiral CT venography in inferior vena cava. Methods: Twenty-eight patients performed MSCT venography in inferior vena cava, including 2 cases with both indirect and direct venography, 10 cases with indirect venography, 20 cases with direct venography through unilateral or bilateral lower extremity venous injection. The image quality and enhancement degree of the inferior vena cava were compared in double-blind method. Results: Of 10 cases with indirect venography of inferior vena cava, 1 case was failed due to mild enhancement in inferior vena cava. Image quality was good in 2 cases, poor in 7 cases, no excellent case. Of 20 cases with direct venography of inferior vena cava, the enhancement degree was scored 1, 2 degree in 16, 4 cases respectively and no case was scored 3 degree, the image quality was excellent, good in 16, 4 cases and no case was bad. The success rate was 100%. Conclusion: The image quality of direct MSCT venography in inferior vena cava is better than that of indirect method. (authors)

Value of multi-slice spiral CT in diagnosis the detection of fish bone impaction in the esophagus

International Nuclear Information System (INIS)

Luo Min; Hu Daoyu; Wang Qiuxia; Pei Yigang

2009-01-01

Objective: To investigate the detection rate and diagnostic value of multi-slice spiral CT scan in detecting fish bone impaction in the esophagus. Methods: Experimental group: 30 fresh water fish bones from three variety classes were divided into three groups with length of (23.36±0.15), (28.51± 0.07) and (30.89±0.10) mm, and diameter of (4.49±0.31), (1.78±0.09) and (0.49±0.07) mm. The fish bones were put into esophagus models in three different types including parallel, perpendicular and oblique. MSCT with axial scan combined with three dimensional reconstruction technique and plain X-ray film ( CR and DR) were used to examine the model. The relations of the number and rate of fish bones were compared between MSCT and X-ray film. Clinical group: MSCT imaging were performed in 20 cases proved by esophageal endoscope or clinical operation, among which 11 cases received plain X-ray film (CR and DR), 15 cases received Barium-soaked cotton and 17 cases received endoscope. Paired Chi-square test was used to compare the differences of detection of fishbone by the different ways. Results: In experimental group: All the 90 cases (100%) fish bones of three different species were clearly revealed on MSCT image; only 60 cases (66.7%) fish bones were revealed by plain X-ray film (CR and DR). The number and rate of fish bones detected by MSCT was higher than that of plain X-ray film (CR and DR) (χ 2 =28.03, P 2 =7.11, P 2 =4.17, P<0.05). Conclusions: The sensitivity and detection rate of fish bone with MSCT was high and could evaluate the surrounding and complications of the esophagus. MSCT could be used as the first examination of impacted fish bones in the esophagus. (authors)

Correlation study of multislice spiral CT and pathology in relationship between solitary pulmonary nodule and bronchus

International Nuclear Information System (INIS)

Qiang Jinwei; Ye Xuanguang; Zhou Kangrong; Jiang Yaping; Wang Qun; Xu Songtao; Tan Lijie

2003-01-01

Objective: To investigate the relationship between solitary pulmonary nodule (SPN) and bronchus and its value in predicting the nature of nodule. Methods: Continuous volume targeted scans of 0.5 mm collimation were prospectively performed with multislice spiral CT (MSCT) and reconstructed images of MPR, CPR, and SSD in workstation in 75 patients of SPN with ≤3 cm in diameter were acquired. The emphasis was paid on the manifestation of the shapes and patterns of SPN with related bronchi. The results were correlated with macroscopic and microscopic specimens. Results: (1) The SPN-bronchus relationship was shown very clearly in all patients by the designed protocol. CT demonstrated the relations between SPN and bronchus in 44 (86.3%) malignant and 16 (66.7%) benign nodules. There was no statistically significant difference (P=0.065). (2) Five types of SPN-bronchus relationship were identified with MSCT. Type I: bronchus was obstructed abruptly by the SPN, type II: bronchus penetrated into SPN with tapered narrow and interruption, type III: bronchus lumen shown within SPN was patent and intact, type IV: bronchus ran at the periphery of SPN with intact lumen, and type V: bronchus was displaced, compressed, and narrowed by SPN. (3) With respect to the nature of SPN, malignant nodule most commonly showed type I, secondly type IV, and rarely type V. Benign nodule most often showed type V, secondly type I, and no type II. With respect to the pattern, type I, II, and IV patterns were more commonly seen in malignant nodule, whereas type V pattern was seen frequently in benign nodule. Type III pattern was slightly more common in benign cases. Conclusion: Spiral targeted scan of ultra-thin section with MSCT and followed by MPR, CPR, and SSD reconstruction can greatly improve the manifestation of the bronchioles and accurately demonstrate the patterns of SPN-bronchus relationship. Varied patterns are corresponding to certain nodule and reflect definite pathologic changes

First experience with multidetector-CT for the diagnosis of coronary atherosclerosis

International Nuclear Information System (INIS)

Becker, C.R.; Hong, C.; Schoepf, U.J.; Reiser, M.F.; Knez, A.; Leber, A.; Treede, H.; Wildhirt, S.; Ohnesorge, B.; Flohr, T.

2000-01-01

Purpose: Multirow-detector-spiral-CT (MSCT) allows for 250 ms effective exposure time. The purpose of this study was to demonstrate the possibilities and limitations of this CT technology for non enhanced and contrast enhanced investigation of the coronary arteries. Methods: Investigation of the coronary arteries without contrast medium for quantification of coronary calcifications was performed in an obese patient (140 kg) with MSCT and electron beam CT (EBCT). In 56 patients contrast enhanced CT angiography of the coronary arteries was performed to determine image quality depending on the heart rate. Results: In the obese patient superior image quality could be achieved with MSCT allowing for reliable quantification of coronary calcifications. With MSCT angiography of the coronary arteries good image quality was achieved in patients with a heart rate of 59±8 beats per minute. Conclusion: Even if there are limitations in patients with higher heart rates with an effective exposure time of 250 ms MSCT has clear advantage of image quality in the assessment of non enhanced and contrast enhanced coronary arteries. (orig.) [de

Early clinical phase of patient's management after polytrauma using 1- and 4-slice helical CT; Fruehes klinisches Management nach Polytrauma mit 1- und 4-Schicht-Spiral-CT

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Kloeppel, R.; Kahn, T. [Klinik und Poliklinik fuer Diagnostische Radiologie, Universitaetsklinikum Leipzig (Germany); Schreiter, D. [Chirurgische Intensivtherapieabteilung, Zentrum fuer Chirurgie, Universitaetsklinikum Leipzig (Germany); Dietrich, J. [Abt. Neuroradiologie der Klinik und Poliklinik fuer Diagnostische Radiologie, Universitaetsklinikum Leipzig (Germany); Josten, C. [Klinik und Poliklinik fuer Unfall- und Wiederherstellungschirurgie, Zentrum fuer Chirurgie, Universitaetsklinikum Leipzig (Germany)

2002-07-01

In the early clinical phase the comprehensive imaging of patients with multiple trauma using helical CT is already established. Aim of this study was to assess whether MSCT may improve the patient management and the diagnostic results.The procedure is designed as follows: after life-thretening treatment x-ray of chest and ultrasound are carried out in the emergency room. Then the patient is moved to CT. From 1998 to december 2000 241 patients were examined using a single slice helical CT (Somatom plus 4), in 2001 79 patients using a 4-slice helical CT (Somatom VZ, Siemens Med.Sol.). After CT selected radiograms of the extremities were taken.359 of 360 procedures were carried out successfully. Excluding 1 case (death during 1-sl. h CT) all relevant lesions of head, neck, and body were diagnosed. Although the patients had an injury severity score of {approx}30. The change from 1slice-helical CT to 4 slice-helical CT allowed us to reduce the stay in the CT room from 28 to 16 min. The total lethality decreased by {approx}4%.Advantages for the patient arose from the standardized examination protocol using multislice CT. If integrated in an interdisciplinary management concept, it is a good compromise between examination time, comprehensive diagnostic imaging, life-saving therapeutic procedures, and therapy planning. (orig.) [German] Die klinische Erstversorgung Polytraumatisierter schliesst inzwischen in vielen Unfallkliniken den fruehzeitigen Einsatz der Spiral-CT ein. Kann die neuerlich eingefuehrte Mehrschicht-Spiral-CT Ergebnisse und Patientenmanagement weiter verbessern?Nach lebensrettenden Sofortmassnahmen, Thoraxroentgen und Notsonographie im Schockraum erfolgte die CT: Von 1998-2000 wurden 241 Patienten mit einem 1-Schicht-Spiral-CT (Somatom plus 4) und in 2001 79 Patienten mit einem 4-Schicht-Spiral-CT (Somatom VZ, beide Siemens Med. Sol.) untersucht. Klinisch ausgewaehlte Extremitaetenaufnahmen wurden ergaenzt.359 von 360 Untersuchungen verliefen erfolgreich

The value of multi-slice spiral CT in the preoperative assessment of living renal donor

International Nuclear Information System (INIS)

Li Qinghai; Yan Fuhua; Xu Pengju; Zhou Meiling; Zhu Tongyu; Xu Ming; Wang Guomin

2008-01-01

Objective: The purpose of this study is to assess the value of multi-slice spiral CT (MSCT) in the preoperative evaluation of living renal donor as a all in one modality. Methods: Thirty-six potential living renal donors underwent the examination using a GE light VCT scanner. Informed consent was obtained from all participants. The plain scan, early arterial phase, late arterial phase and excretory phase scans are performed in the former 25 donors (injection rate 5 rolls, total volume 100 mi, tube tension 120 kV). While in the later 11 donors (2 ml/s 40 ml +4 ml/s 60 ml), the scanning protocol included the plain scan ( 100 kV), vascular phase and excretory phase scans (100 kV). The excretory phase data were used in the reconstruction of CT urography in both groups. All images were reviewed by one radiologist and one urologist, and the findings of MSCT were compared with intraoperative findings for 33 donors, to investigate the utilities of MSCT in assessing renal vascularity, urinary tract and lesions of renal parenchyma. When discrepancies are found between the two reviewers, consensus was obtained via discussion. Au data was statiscally processed with SPSS for Windows. Results: MSCT angiography is in accordance with intraoperative findings in demonstrating the anatomy of renal arteries and renal vein trunk, accesary arteries, early branching of renal artery. The findings from CTA are highly in accordance with the intraoperative findings, which facilitate intraoperative ligation and reduce relevant complications. CTU demonstrates the anatomy of urinary, tract in good agreement with the intraoperative findings. The image quality of 3D vascularity and CTU between the two groups, scored 4.4 ± 1.2 vs 4.2 ± 1.3 and 4.6 ± 0.8 vs 4.4 ± 0.9 respectively, no statistical between-groups difference was found (Z=-0.89, -0.47, P>0.05). Conclusion: MSCT multiphase scanning combined with CTA and CTU play a important role in the evaluation of living renal donor, which

The technique advantages of 16-detector multic-slice spiral CT in evaluating combined pulmonary and deep vein thromboembolism

International Nuclear Information System (INIS)

Xia Shuang; Qi Ji; Lei Xinwei; Wen Lianqing; Li Yiming; Liu Jisheng

2004-01-01

Objective: To study the scanning technique of 16-detector multic-slice spiral CT(MSCT) for combined pulmonary artery and deep vein of lower limb in pulmonary thromboembolism (PE) patients. Methods: Forty suspected pulmonary thromboembolism patients were performed both pulmonary artery angiography (CTA) and indirect deep vein venography (CTV) on 16-detector MSCT. The parameters of the latter as following: total contrast volume 120-150 ml, injection rate 4.0-4.5 ml/s (from antecubital vein), delay time 4.0 for CTA 20-23 s, CTV 120-180 s, collimation for CTA 1.25 mm and 0.625 mm, CTV 2.5 mm, scan range of CTV: from popliteal vein to the level of bilateral renal vein into the inferior vena cava. Postprocessing include MPR, MIP, and VR. The test was used to analyzed the images. Results: Twenty five patients had both pulmonary thromboembolism (PE) and deep vein thromboembolism (DVT), 8 patients had only DVT, 2 had only PE, and 5 had neither. There was no difference between different collimation in depicting thrombus. The CT value number of enhanced pulmonary artery and lower deep vein was obviously higher than the thrombus. The value of MPR, MIP, VR for PE was 100%, 100%, and 65%, The value of MPR, MIP, VR for DVT is 100%, 60%, and 50%. Conclusion: The technique of combined pulmonary CTA and deep vein CTV of 16-detector MSCT will provide a new modality for pulmonary thromboembolism patients. (author)

A dynamic approach to identifying desired physiological phases for cardiac imaging using multislice spiral CT

International Nuclear Information System (INIS)

Vembar, M.; Garcia, M.J.; Heuscher, D.J.; Haberl, R.; Matthews, D.; Boehme, G.E.; Greenberg, N.L.

2003-01-01

In this investigation, we describe a quantitative technique to measure coronary motion, which can be correlated with cardiac image quality using multislice computed tomography (MSCT) scanners. MSCT scanners, with subsecond scanning, thin-slice imaging (sub-millimeter) and volume scanning capabilities have paved the way for new clinical applications like noninvasive cardiac imaging. ECG-gated spiral CT using MSCT scanners has made it possible to scan the entire heart in a single breath-hold. The continuous data acquisition makes it possible for multiple phases to be reconstructed from a cardiac cycle. We measure the position and three-dimensional velocities of well-known landmarks along the proximal, mid, and distal regions of the major coronary arteries [left main (LM), left anterior descending (LAD), right coronary artery (RCA), and left circumflex (LCX)] during the cardiac cycle. A dynamic model (called the 'delay algorithm') is described which enables us to capture the same physiological phase or 'state' of the anatomy during the cardiac cycle as the instantaneous heart rate varies during the spiral scan. The coronary arteries are reconstructed from data obtained during different physiological cardiac phases and we correlate image quality of different parts of the coronary anatomy with phases at which minimum velocities occur. The motion characteristics varied depending on the artery, with the highest motion being observed for RCA. The phases with the lowest mean velocities provided the best visualization. Though more than one phase of relative minimum velocity was observed for each artery, the most consistent image quality was observed during mid-diastole ('diastasis') of the cardiac cycle and was judged to be superior to other reconstructed phases in 92% of the cases. In the process, we also investigated correlation between cardiac arterial states and other measures of motion, such as the left ventricular volume during a cardiac cycle, which earlier has been

Diagnosis of pancreatic tumors by spiral angio CT

International Nuclear Information System (INIS)

Miura, Kohi; Nakao, Norio; Takayasu, Yukio; Okawa, Tomohisa

1995-01-01

Spiral angio were performed with injection of 30 ml of contrast material at a rate of 1 ml/sec with a scan delay of 6 sec through catheter into the celiac artery while the blood flow of the superior mesenteric artery (SMA) was occluded by the inflated balloon catheter. Spiral CT scans were obtained using Somatom Plus (Siemens). Parameter for spiral CT were 24-sec acquisition time, 5 mm collimation, 5 mm/sec table incrementation. Reconstructions were performed every 5 mm. Pancreatic cancers were characteristically depicted with spiral angio CT as hypodensity relative to normal enhanced pancreatic parenchyma. On dynamic angio CT studies performed in pancreatic cancers, the area of cancer and normal parenchyma had maximum level of enhancement at 10-15 sec after injection of contrast material via catheter into the celiac, and there was no difference in enhancement between tumor and normal parenchyma. On the other hand, the lesions of cancer were revealed as hypodensity with spiral angio CT. In case of chronic pancreatitis, the enhancement of the entire pancreas obtained with spiral angio CT was homogeneous. Insulinoma in the tail of pancreas was detected by spiral angio CT but was not detected by both selective angiography and conventional CT. Three-dimensional (3-D) rendering spiral angio CT data shows the extent of vascular involvement by pancreatic cancer and provides useful information for surgical planning. Spiral angio CT is the most useful procedure for diagnosis of pancreatic tumor. (author)

Clinical implications of immediate or later periportal edema in MS-CT trauma scans: surrogate parameter of intravenous fluid status and venous congestion.

Science.gov (United States)

Kleber, C; Buschmann, C T

2013-06-01

Periportal edema (PPE) of the liver in multislice computed tomography (MS-CT) scans that develops immediately (primary PPE [pPPE]) or later (secondary PPE [sPPE]) is not uncommon in severe trauma patients. Although PPE may serve as a marker for blunt abdominal trauma (22-31 % of cases), distinct causes and clinical implications of PPE are unclear. We analyzed the incidence of pPPE and sPPE in 68 MS-CT scans in severe trauma patients (2007-2009). Exclusion criteria were severely burned patients and patients with preexistent liver diseases predisposing to PPE. We divided PPE+ patients into two subpopulations-either initial/primary PPE (pPPE+) or later/secondary PPE (sPPE+). Further patient data were collected and statistically analyzed. PPE+ was found in 27.9 % (n = 19). Females predominated (p = 0.01), and PPE+ patients presented with a significantly better pH at admission (p = 0.008). The total amount of volume resuscitation (1,983 ± 1,155 ml; p = 0.02) and crystalloids (1,117 ± 796 ml; p = 0.006) administered before MS-CT scans was significantly higher in PPE+, whereas the amount of administered colloids (797 ± 640 ml) showed no significant difference in both groups. PPE+ was not associated with further patient data, i.e., trauma mechanism, injury severity, prognosis-relevant factors, adverse clinical events, or mortality. pPPE+ in MS-CT may serve as a surrogate parameter for intravenous volume load and/or venous congestion, and sPPE+ may also indicate venous congestion and right heart failure after severe trauma. In severe trauma patients with pPPE+/sPPE+ in MS-CT scans, causes of PPE relating to intravenous fluid overload and/or venous congestion should be excluded or treated.

Spiral CT versus conventional CT in the preoperative assessment of metallic intraocular foreign bodies

International Nuclear Information System (INIS)

Prokesch, R.; Bankier, A.; Ba-Ssalamah, A.; Imhof, H.; Lakits, A.; Scholda, C.

1998-01-01

Purpose: To compare the effectiveness of spiral CT versus conventional CT in the preoperative assessment of metallic intraocular foreign bodies. Results: All foreign bodies were detected by each scanning modality on the axial and on the reconstructed planes. The quality of the axial images was similar for spiral and conventional CT. The spiral technique provided high-quality reconstructed images which allowed accurate localization of the foreign bodies in all cases. Reconstructions by conventional technique were inadequate for preoperative assessment. The examination time for the total orbital volume was 18 s for spiral CT and 52 s for conventional CT. Radiation dose delivered to the lens was 35 mGy for spiral CT and 56 mGy for conventional CT axial scanning. Conclusion: Spiral CT multiplanar offers several significant advantages for the preoperative assessment of metallic intraocular foreign bodies compared to the conventional CT technique in clinical practice, including short examination time, minimized motion artifacts, reduced radiation exposure, and accurate localization. (orig.) [de

Comparison of multi-slice CT (MSCT) and TI-201 myocardial SPECT in detection of coronary artery disease: relation to coronary arteriography

Energy Technology Data Exchange (ETDEWEB)

Pai, M. S.; Kim, Y. K.; Shim, S. S. [College of Medicine, Univ. of Ewha Womens, Seoul (Korea, Republic of)

2003-07-01

To evaluate the diagnostic potentials of MSCT and TI-201 SPECT in the assessment of coronary artery disease. Twenty-four patients (15 men, 9 women, 42-79 years) with clinically suspected coronary artery disease were studied by TI-201 myocardial SPECT and MSCT. MSCT data were obtained with 12 x 0.75 mm, 420ms rotation, multi-slice CT scanner (SOMATOM Sensation, Siemens) using non-ionic contrast, 80ml, 4ml/sec. Multiplanar reconstruction techniques were used for evaluation of coronary arteries. TI-201 myocardial SPECT were performed at stress with adenosine and at rest. Data from MSCT and TI-201 SPECT were compared territory by territory (divided into two segments; LAD and RCA/LCx) and related to coronary arteriography, in which more than 60% stenoses are regarded as significant. MSCT and TI-201 SPECT showed agreement in 37 out of 48 segments (77.1%). Out of 11 disagreed segments (22.9), TI-201 SPECT was superior in 6 segments and MSCT was superior in 5 segments. Sensitivities and specificities of MSCT and TI-201 SPECT by coronary arteriography are 81.8%, 69.2% and 86.3%, 76.9%, respectively. Agreed 4 segments between MSCT and TI-201 SPECT exhibited results that differ from the results of coronary arteriography. Myocardial bridge in two cases were detected as significant stenoses by MSCT but showed normal perfusion in TI-201 SPECT. Agreement between MSCT and TI-201 SPECT in the assessment of coronary artery disease was good but TI-201 SPECT has higher sensitivity and specificity for the detection of jeopardized myocardium than MSCT. MSCT and TI-201 SPECT provide complementary information in the assessment of coronary artery disease and could help reduce probable mistake in the interpretation of hemo dynamically insignificant lesion in coronary arteriography.

The effect of pitch in multislice spiral/helical CT

International Nuclear Information System (INIS)

Wang, G.; Vannier, M.W.

2000-01-01

The purpose of this study is to understand the effect of pitch on raw data interpolation in multislice spiral/helical computed tomography (CT) and provide guidelines for scanner design and protocol optimization. Multislice spiral CT is mainly characterized by the three parameters: the number of detector arrays, the detector collimation, and the table increment per x-ray source rotation. The pitch in multislice spiral CT is defined as the ratio of the table increment over the detector collimation in this study. In parallel to the current framework for studying longitudinal image resolution, the central fan-beam rays of direct and opposite directions are considered, assuming a narrow cone-beam angle. Generally speaking, sampling in the Radon domain by the direct and opposite central rays is nonuniform along the longitudinal axis. Using a recently developed methodology for quantifying the sensibility of signal reconstruction from non-uniformly sampled finite points, the effect of pitch on raw data interpolation is analyzed in multislice spiral CT. Unlike single-slice spiral CT, in which image quality decreases monotonically as the pitch increases, the sensibility of raw data interpolation in multislice spiral CT increases, suggesting that image quality does not decrease monotonically in this case. The most favorable pitch can be found from the sensitivity-slice spiral CT is provided. The study on the effect of pitch using the sensitivity analysis approach reveals the fundamental characteristics of raw data interpolation in multislice spiral CT, and gives insights into interaction between pitch and image quality. These results may be valuable for design of multislice spiral CT scanners and imaging protocol optimization in clinical applications. (authors)

Diagnosis of tracheal instability: inspiratory and expiratory spiral CT and cine CT

International Nuclear Information System (INIS)

Heussel, C.P.; Thelen, M.; Kauczor, H.U.; Hafner, B.; Lill, J.

2000-01-01

Purpose: In tracheo- and bronchomalacia, localization and determination of collapse is necessary for planning a surgical procedure. We compared inspiratory and spiral CT, cine CT, and bronchoscopy and evaluated the relevance of each method. Methods: Seventeen patients with suspected or verified tracheal stonosis or collapse underwent paired inspiratory and exspiratory spiral CT and cine CT during continuous respiration (temporal increment 100 ms). The tracheal cross-sectional area was calculated and compared. Results: In addition to bronchoscopy, further information concerning localization, extent, collapse, stability of the tracheal wall, distal portions of the stenosis, and extraluminal compressions was obtained. A significantly higher degree of tracheal collapse was seen using cine CT compared to paired spiral CT (p [de

Floating venous thrombi: diagnosis with spiral-CT-venography; Diagnose flottierender venoeser Thromben mittels Phlebo-Spiral-CT

Energy Technology Data Exchange (ETDEWEB)

Gartenschlaeger, M. [Mainz Univ. (Germany). Klinik fuer Radiologie; Klose, K.J. [Univ. Marburg, Medizinisches Zentrum fuer Innere Medizin, Abt. Poliklinik (Germany); Schmidt, J.A. [Univ. Marburg, Medizinisches Zentrum fuer Radiologie, Abt. fuer Strahlendiagnostik (Germany)

1996-05-01

Local application of contrast agent into an ipsilateral dorsal foot vein and spiral CT were used to examine 16 consecutive cases with deep venous thrombosis proven at conventional venography; in addition, colour Doppler flow imaging was performed. At conventional venography, 8/16 thrombi appeared to be floating and the remaining 8/16 were adherent to the vessel wall. Spiral-CT showed 15/16 thrombi to be adherent to the vessel wall; the floating thrombus correlated with findings in conventional venography. At colour Doppler flow imaging 3/16 thrombi were considered floating, one of them was discordant to conventional venography. The comparison of conventional venography to spiral-CT demonstrates complete agreement for adherence to vessel wall seen in conventional venography (p=1,0) and significant discordance in cases with free-floating appearance in conventional venography. Adherence of thrombi to the wall of the vessel at conventional venography is in agreement with computed tomography. Conventional venography probably overestimates the prevalence of free floating thrombi. (orig./MG) [Deutsch] Mittels lokaler Kontrastmittelapplikation in eine ipsilaterale Fussrueckenvene und Spiral-CT wurden 16 konsekutive Faelle konventionell phlebographisch gesicherter Phlebothrombose untersucht, zusaetzlich wurde die farbkodierte Doppler-Ultraschalluntersuchung durchgefuehrt. In der konventionellen Phlebographie waren 8/16 Thromben flottierend, die uebrigen 8/16 wandadhaerent. In der Spiral-CT zeigten sich Wandadhaerenzen in 15/16 Faellen; der nachgewiesene flottierende Thrombus stimmte mit der konventionellen Phlebographie ueberein. Im farbkodierten Doppler-Ultraschall erschienen die Thromben in 3/16 Faellen flottierend, darunter ein von der konventionellen Phlebographie abweichender Befund. Der Vergleich von konventioneller und CT-Phlebographie ergab eine komplette Uebereinstimmung fuer konventionell phlebographisch nachgewiesene Wandadhaerenz und eine signifikante Abweichung

Spiral CT manifestations of spherical pneumonia

International Nuclear Information System (INIS)

Li Xiaohong; Yang Hongwei; Xu Chunmin; Qin Xiu

2008-01-01

Objective: To explore the Spiral CT manifestations and differential diagnosis of spherical pneumonia. Methods: 18 cases of spherical pneumonia and 20 cases of peripheral pulmonary carcinoma were selected, both of them were confirmed by clinic and/or pathology. The SCT findings of both groups were compared retrospectively. Results: Main spiral CT findings of spherical pneumonia were showed as followings: square or triangular lesions adjacent to pleura; with irregular shape, blurry, slightly lobulated margin, sometimes with halo sign. Small inflammatory patches and intensified vascular markings around the lesions were seen. Lesions became smaller or vanished after short-term anti-inflammatory treatment. Conclusion: Spherical pneumonia showed some characteristics on Spiral CT scan, which are helpful in diagnosis and differential diagnosis of this disease. (authors)

Measurement of lung volumes : usefulness of spiral CT

International Nuclear Information System (INIS)

Kang, Ho Yeong; Kwak, Byung Kook; Lee, Sang Yoon; Kim, Soo Ran; Lee, Shin Hyung; Lee, Chang Joon; Park, In Won

1996-01-01

To evaluate the usefulness of spiral CT in the measurement of lung volumes. Fifteen healthy volunteers were studied by both spirometer and spiral CT at full inspiration and expiration in order to correlated their results, including total lung capacity (TLC), vital capacity (VC) and residual volume (RV). 3-D images were reconstructed from spiral CT, and we measured lung volumes at a corresponding CT window range ; their volumes were compared with the pulmonary function test (paired t-test). The window range corresponding to TLC was from -1000HU to -150HU (p=0.279, r=0.986), and for VC from -910HU to -800HU (p=0.366, r=0.954) in full-inspiratory CT. The optimal window range for RV in full-expiratory CT was from -1000HU to -450HU (p=0.757, r=0.777), and TLC-VC in full-inspiratory CT was also calculated (p=0.843, r=0.847). Spiral CT at full inspiration can used to lung volumes such as TLC, VC and RV

Diagnosis of multidetector spiral CT and its reconstruction techniques in trachea and principal bronchus tumors

Energy Technology Data Exchange (ETDEWEB)

Mingyue, Luo; Hong, Shan; Zaibo, Jiang; Lufang, Li; Jiansheng, Zhang [Zhongshan Univ., Guangzhou (China). The Third Univ. Hospital, Dept. of Radiology; Lijia, Gu; Shaohong, Huang; Yi, Jin; Zhiqiang, Hou

2003-12-01

Objective: To investigate the clinical diagnostic value of multidetector spiral CT (MSCT) and its reconstruction techniques including multiplanar volume reformation (MPVR), volume rendering (VR), and virtual bronchoscopy (VB) in the trachea and principal bronchus tumors. Methods: Thin slice MSCT scanning was performed in 31 patients with suspected trachea or principal bronchus tumors, and image reconstruction data were formed after retro-reconstructing of initial scanning data. MPVR, VR, and VB images were obtained respectively by postprocessing of image reconstruction data with MPVR, VR, and VB image processing software in AW workstation. The findings of MSCT initial axial images, MPVR, VR, and VB images were compared with surgical and pathological results. Results: MSCT initial axial images combined with MPVR, VR, and VB images displayed the locations (tracheae, n=19; right principal bronchi, n=6; left principal bronchi, n=6), morphologies (endoluminal nodular tumors with narrow bases, n=2; endoluminal nodular tumors with wide bases, n=13; intraluminal and extraluminal massive tumors, n=16), internal features (1 had homogeneous density, 1 had low density, they both without obvious enhancement; 23 squamous cell carcinomas and 3 adenocarcinomas had fairly homogeneous density and rather obvious enhancement; 1 had homogeneous density, 1 had inhomogeneous density, 1 had punctate calcification, all with obvious enhancement), extramural invasion situations (broke through only serous membrane, n=1; no clear border with right atelectatic lung tissue, n=1; ranges of extramural invasion 4-56 mm, n=14), morphologies of luminal stenoses (eccentric, n=1; irregular, n=26; circular, n=3; conical interruption, n=1), extents (mild, n=5; moderate, n=7; severe, n=19); measured longitudinal invasion ranges (only 3 mm, n=1; invaded the whole right principal bronchus wall and carina, n=1; 5-68 mm, n=29), and distances between principal bronchus tumors and carina (invaded carina, n=1

Kidney spiral CT, indications, realization, results

International Nuclear Information System (INIS)

Braunschweig, R.; Beilicke, M.; Hundt, W.; Breiteneder, T.; Reiser, M.

1999-01-01

The introduction of spiral computed tomography (spiral CT) has vastly enriched the methodologically diversity of computer-tomographic scans. It allows for the recording of different perfusion or excretion stages of the kidney parenchyma of the urine draining paths by carrying out long-distance, phase-identical multiple examinations of the retroperitoneum. The description of the findings which are characterized by their local and contrasts behavior is possible. The following report describes the indications and technological process of kidney spiral CT using kidney-typical intravenous contrast media. Special emphasis is put on the advantages and limits of multiple phase spiral CT. Decisive preconditions are: 1. Specific clinical query, 2. selection of the corresponding phase contrasts of the kidneys and uretra or bladder, 3. exact technical and temporal adjustment of the acquisition parameters. Scanning times are in the range of seconds. The overall examination can be carried out quick and without any major strain on the part of the patient. A sound proof and a general differentiation of focal kideny lesions can be derived from the acquired data. This is also true for kidneys and ureters findings. Bladder findings can be localized and differentiated according to stage. More than two 'spiral acquisitions' should be carried out with restraint taking exposure to radiation into account. Due to the sound registration of focal lesions, its capability of reproduction and its short-time examination, the spiral CT of the kidneys can be said to be the most effective current scanning method of the retroperitoneum following clinical examinations and sonography. (orig.) [de

The potentials of spiral CT for detection of focal liver lesions; Moeglichkeiten der Spiral-CT zur Diagnostik fokaler Leberlaesionen

Energy Technology Data Exchange (ETDEWEB)

Helmberger, H. [Technische Univ. Muenchen, Klinikum rechts der Iser, Inst. fuer Roentgendiagnostik (Germany); Kersting-Sommerhoff, B. [Technische Univ. Muenchen, Klinikum rechts der Iser, Inst. fuer Roentgendiagnostik (Germany); Lenz, M. [Technische Univ. Muenchen, Klinikum rechts der Iser, Inst. fuer Roentgendiagnostik (Germany); Kirsten, R. [Technische Univ. Muenchen, Klinikum rechts der Iser, Inst. fuer Roentgendiagnostik (Germany); Bautz, W. [Technische Univ. Muenchen, Klinikum rechts der Iser, Inst. fuer Roentgendiagnostik (Germany)

1996-03-01

Spiral CT currently is the modality of choice for all aspects of diagnostic evaluation of the liver. Optimal selection of treatment should be based inter alia on the findings obtained by spiral CT with arterial application of contrast medium, as for example S-CTA (primary liver tumors), or S-CTAP (secondary liver tumors). Ultrasonography is the major supplementing modality. In the near future, MR imaging applying liver-specific contrast-enhancing agents is expected to become an important competing technique, and further developments of interest in diagnostic imaging of the liver are in the offing: it is not yet known which technique will be the modality of choice at the onset of the 21st century. (orig.) [Deutsch] Die Spiral-CT ist zur Zeit das empfehlenswerte Verfahren fuer alle Fragen der Leberdiagnostik. Zur optimalen praetherapeutischen Beurteilung der Leber sollte die Spiral-CT mit arterieller Kontrastmittelapplikation als S-CTA (primaere Lebertumoren) bzw. S-CTAP (sekundaere Lebertumoren) durchgefuehrt werden. Der US kommt ein Stellenwert als ergaenzende Methode zu. In Zukunft wird die MRT mit leberspezifischen Kontrastmitteln ein konkurrierendes Verfahren zur Spiral-CT darstellen, wobei eine weitere interessante Entwicklung auf dem Gebiet der hepatischen Bildgebung zu erwarten ist: Das diagnostische Verfahren der Wahl fuer die Leber zu Beginn des 21. Jahrhunderts ist noch nicht definiert. (orig.)

Spiral CT for evaluation of chest trauma

International Nuclear Information System (INIS)

Roehnert, W.; Weise, R.

1997-01-01

After implementation of spiral CT in our department, we carried out an analysis for determining anew the value of CT as a modality of chest trauma diagnosis in the emergency department. The retrospective study covers a period of 10 months and all emergency patients with chest trauma exmined by spiral CT. The major lesions of varying seriousness covered by this study are: pneumothorax, hematothorax, pulmonary contusion or laceration, mediastinal hematoma, rupture of a vessel, injury of the heart and pericardium. The various fractures are not included in this study. In many cases, spiral CT within relatively short time yields significant diagnostic findings, frequently saving additional angiography. A rigid diagnostic procedure cannot be formulated. Plain-film chest radiography still remains a diagnostic modality of high value. (Orig.) [de

Substantial dose reduction in modern multi-slice spiral computed tomography (MSCT)-guided craniofacial and skull base surgery

International Nuclear Information System (INIS)

Widmann, G.; Fasser, M.; Jaschke, W.; Bale, R.; Schullian, P.; Zangerl, A.; Puelacher, W.; Kral, F.; Riechelmann, H.

2012-01-01

Purpose: Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs). Materials and Methods: An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120 kV/100 mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100 kV/35ref. mAs, (LD-II) 80 kV/40 - 41ref. mAs, and (LD-III) 80 kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05). Results: CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1,62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt fuer Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols. Conclusion: Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery. (orig.)

Diagnosis of acute appendicitis with MSCT

International Nuclear Information System (INIS)

Li Xi

2011-01-01

Objective: To analyze the CT appearance of acute appendicitis and investigate diagnostic value of MSCT on acute appendicitis. Methods: The type and CT appearance of 15 cases with acute appendicitis proved by surgery and histopathology or clinic was analyzed retrospectively. Multi-stages scanning was carried out on the whole abdomen with 16 row CT. Post processing techniques including MPR, CPR and MIP were performed to observe the lesions. Results: There were 3 acute suppurative appendicitis, 12 acute gangrene and perforative appendicitis and appendiceal abscess. Complication occurred in 10 cases with gangrene and perforative appendix or appendix molten. The complication included 4 pelvic abscess, 3 intra-abdminal abscess, 1 combined pelvic and intra-abdominal abscess, 4 conglutination bowel obstruction, 1 ureteritis stegnosis and 1 abdominal wall fistulae. The exact ratio of CT diagnosis on acute suppurative appendicitis and appendiceal abscess reached 93.3% preoperatively. It is difficult to distinguish between acute suppurative appendicitis and acute gangrenous appendicitis without perforation. Conclusion: The MSCT appearance of acute appendicitis was marked and of important value on diagnosis of acute appendicitis. (authors)

The diagnostic value of multi-slice CT on the congenital malformation of coronary sinus

International Nuclear Information System (INIS)

Li Wei; Ma Xiaojing; Sun Qingjun

2012-01-01

Objective: To investigate the application value of multi-slice spiral CT on the congenital malformation of coronary sinus. Methods: MSCT finding of 98 patients with coronary sinus malformation confirmed by surgery were retrospectively analyzed,and the cases were divided into four categories based on the Mantini theory and comparison was made between the diagnosis from ultrasound and CT. A 2 × 2 table for Chi-square test was also used for statistics analysis. Results: Among 98 patients,there were 72 patients with persistent left superior vena cava reflowed to right atria through coronary sinus, with 48 patients diagnosed by ultrasound and 72 patients by MSCT; there were 13 patients with anomalous pulmonary venous connection to coronary sinus, with 12 patients diagnosed by ultrasound and 13 patients by MSCT diagnosis; there were 10 patients with unroofed coronary sinus syndrome, with 6 patients diagnosed by ultrasound and 8 patients by MSCT, there were 2 patients with coronary sinus atresia, all diagnosed by MSCT; there were 1 patient with coronary sinus anomaly reflow to left arita. The significant difference between 2 modalities (χ 2 =22.7, P<0.01) shows that CT is superior to ultrasound. Conclusion: MSCT is much more better than ultrasound in the diagnosis of malformation of coronary sinus and it can provide reliable diagnosis prior to surgery or interventional therapy. (authors)

Assessment of coronary arteries in infants by 64-detector-row multislice spiral computed tomography

International Nuclear Information System (INIS)

Tahara, Masahiro; Waki, Chiaki; Komatsu, Hiroaki; Hayashi, Tomohiro; Sato, Tomoyasu

2008-01-01

Heart rate is one of the most important factors for optimal visualization of cardiac CT. We investigated the relation between heart rate and visibility of the coronary arteries with 64-detector row multislice spiral computed tomography (MSCT). Three simulated coronary artery stenosis models (3, 4, and 5 mm) were attached to a moving heart phantom and scanned using 64-detector row MSCT. The heart rate of the phantom was varied between 60 and 150 beats per minutes (bpm). The visibility of simulated coronary arteries was assessed in comparison between cardiac half reconstruction (CHR) and multi-sector reconstruction (MSR). Then contrast-enhanced 64-detector row MSCT was performed in 16 patients under 3 years of age with congenital heart disease and Kawasaki disease without heart rate control. The visibility of coronary artery segments was graded on a three-point scale. The simulated coronary artery patency was detected in the moving phantom at maximum heart rate (150 bpm) with MSR. Minimum lumen diameter was 0.75 mm. Electrocardiogram (ECG)-gated cardiac CT was performed in 9 patients, and non-ECG-gated cardiac CT was performed in 7 patients. The origin and proximal course of coronary arteries in all 9 patients with ECG-gated acquisition were visually evaluated. 64-detector row MSCT with ECG-gated acquisition is able to visualize the origin and proximal course of coronary arteries in infants under 3 years of age. (author)

Principles of spiral CT: III. Quality assurance

International Nuclear Information System (INIS)

Suess, C.; Kalender, W.A.

1998-01-01

Since its introduction in 1989 spiral CT has gained wide clinical acceptance and meanwhile it covers a large range of CT applications. This new technology, however, has not yet been recognized and acknowledged in the national or international regulations on scanner quality assurance (QA) programs. The conventional QA procedures should be extended to check the distribution of resolution and noise within the image plane. Imaging performance in the axial direction constitutes one of the major advantages of spiral scanning. Therefore, the slice sensitivity profiles and the spatial and low-contrast resolution along the z-axis have to be assessed. The high demands on table feed accuracy require additional tests. We suggest phantoms and procedures to check and quantify these parameters. Thereby, we hope to support the ongoing discussion about spiral CT quality assurance. (orig.) [de

A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

International Nuclear Information System (INIS)

Liang Xin; Lambrichts, Ivo; Sun Yi; Denis, Kathleen; Hassan, Bassam; Li Limin; Pauwels, Ruben; Jacobs, Reinhilde

2010-01-01

Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G, Accuitomo 3D, i-CAT, Galileos, Scanora 3D) and one MSCT scanner (Somatom Sensation 16). A 3D surface bone model was created from the six systems. The reference (gold standard) 3D model was obtained with a high resolution laser surface scanner. The 3D models from the five systems were compared with the gold standard using a point-based rigid registration algorithm. Results: The mean deviation from the gold standard for MSCT was 0.137 mm and for CBCT were 0.282, 0.225, 0.165, 0.386 and 0.206 mm for the i-CAT, Accuitomo, NewTom, Scanora and Galileos, respectively. Conclusion: The results show that the accuracy of CBCT 3D surface model reconstructions is somewhat lower but acceptable comparing to MSCT from the gold standard.

Diagnosing extracranial atherosclerotic diseases with spiral CT

International Nuclear Information System (INIS)

Moran, C.J.; Vannier, M.W.; Erickson, K.K.; Broderick, D.F.; Kido, D.K.; Yoffie, R.L.

1991-01-01

This paper reports that this discovery study was performed to determine whether extracranial carotid artery plaques could be diagnosed with a new CT technique (spiral CT) that allows nondistorted three-dimensional (3D) reconstructions in the z axis. Twenty carotid arteries were examined with spiral CT in normal volunteers and in patients suspected of having atherosclerotic plaques in the extracranial carotid arteries. The Somatom Plus CT table was advanced at a constant rate, the x-ray tube was continuously rotated, and 3D data were continuously acquired. Sixty milliliters of nonionic contrast medium was injected intravenously previous to and during the acquisition of data. The carotid bifurcations were identified in all patients. Planar images, similar to conventional intraarterial angiograms, were routinely produced from the volumetric CT data

Multislice helical CT (MSCT) for mid-facial trauma: optimization of parameters for scanning and reconstruction

International Nuclear Information System (INIS)

Dammert, S.; Funke, M.; Obernauer, S.; Grabbe, E.; Merten, H.A.

2002-01-01

Purpose: To determine the optimal scan parameters in multislice helical CT (MSCT) of the facial bone complex for both axial scanning and multiplanar reconstructions. Material and Methods: An anthropomorphic skull phantom was examined with a MSCT. Axial scans were performed with continuously increasing collimations (4 x 1.25 - 4 x 2.5 mm), tube current (20 - 200 mA) and table speeds (3.75 mm/rot. and 7.5 mm/rot.). Multiplanar reconstructions in coronal and parasagittal planes with different reconstruction increment and slice thickness were evaluated in terms of image noise, contour artifacts and visualisation of anatomical structures. Results: The best image quality was obtained with a collimation of 4 x 1.25 mm and a - table speed of 3.75 mm/rot. A reconstruction increment of 0.6 mm achieved the best time to image quality relation. With these parameters the bone structures were depicted in an optimal way without artifacts. The tube current could be reduced to 50 mA without significant loss of image quality. The optimized protocol was used for regular routine examinations in patients with facial trauma (n = 66). Conclusions: Low-dose MSCT using thin collimation, low table speed and small reconstruction increments provides excellent data for both axial images and multiplanar reconstructions in patients with facial trauma. An additional examination in coronal orientation is therefore no longer necessary. (orig.) [de

Choice ofoptimal phase for liver angiography and multi-phase scanning with multi-slice spiral CT

International Nuclear Information System (INIS)

Fang Hong; Song Yunlong; Bi Yongmin; Wang Dong; Shi Huiping; Zhang Wanshi; Zhu Hongxian; Yang Hua; Ji Xudong; Fan Hongxia

2008-01-01

Objective: To evaluate the efficacy of test bolus technique with multi-slice spiral CT (MSCT) for determining the optimal scan delay time in CT Hepatic artery (HA)-portal vein (PV) angiography and multi-phase scanning. Methods: MSCT liver angiography and multi-phase scanning were performed in 187 patients divided randomly into two groups. In group A (n=59), the scan delay time was set according to the subjective experiences of operators; in group B (n=128), the scan delay time was determined by test bolus technique. Abdominal aorta and superior mesenteric, vein were selected as target blood vessels, and 50 HU was set as enhancement threshold value. 20 ml contrast agent was injected intravenously and time-density curve of target blood vessels were obtained, then HA-PV scanning delay time were calculated respectively. The quality of CTA images obtained by using these 2 methods were compared and statistically analysed using Chi-square criterion. Results: For hepatic artery phase, the images of group A are: excellent in 34 (58%), good in 17 (29%), and poor in 8 (13%), while those of group B are excellent in 128(100%), good in 0(0%), and poor in 0(0%). For portal vein phase, the images of group A are: excellent in 23 (39%), good in 27 (46%), and poor in 9 (15%), while those of group B are excellent in 96 (75%), good in 28 (22%), and poor in 4 (3%) respectively. There was statistically significant difference between the ratios of image quality in group A and group B (χ 2 =14.97, 9.18, P< 0.05). Conclusion: Accurate scan delay time was best determined by using test bolus technique, which can improve the image quality of liver angiography and multi-phase scanning. (authors)

Multislice spiral computed tomography to determine the effects of a recruitment maneuver in experimental lung injury

Energy Technology Data Exchange (ETDEWEB)

Henzler, Dietrich; Rossaint, Rolf [University Hospital, RWTH Aachen, Anesthesiology Department, Aachen (Germany); Mahnken, Andreas H.; Wildberger, Joachim E.; Guenther, Rolf W. [University Hospital of the RWTH Aachen, Clinic of Diagnostic Radiology, Aachen (Germany); Kuhlen, Ralf [University Hospital of the RWTH Aachen, Operative Intensive Care Department, Aachen (Germany)

2006-06-15

Although recruitment of atelectatic lung is a common aim in acute respiratory distress syndrome (ARDS), the effects of a recruitment maneuver have not been assessed quantitatively. By multislice spiral CT (MSCT), we analyzed the changes in lung volumes calculated from the changes in the CT values of hyperinflated (V{sub HYP}), normally (V{sub NORM}), poorly (V{sub POOR}) and nonaerated (V{sub NON}) lung in eight mechanically ventilated pigs with saline lavage-induced acute lung injury before and after a recruitment maneuver. This was compared to single slice analysis near the diaphragm. The increase in aerated lung was mainly for V{sub POOR} and the less in V{sub NORM}. Total lung volume and intrathoracic gas increased. No differences were found for tidal volumes measured by spirometry or determined by CT. The inspiratory-expiratory volume differences were not different after the recruitment maneuver in V{sub NON} (from 62{+-}18 ml to 43{+-}26 ml, P=0.114), and in V{sub NORM} (from 216{+-}51 ml to 251{+-}37 ml, P=0.102). Single slice analysis significantly underestimated the increase in normally and poorly aerated lung. Quantitative analysis of lung volumes by whole lung MSCT revealed the increase of poorly aerated lung as the main mechanism of a standard recruitment maneuver. MSCT can provide additional information as compared to single slice CT. (orig.)

Multislice spiral computed tomography to determine the effects of a recruitment maneuver in experimental lung injury

International Nuclear Information System (INIS)

Henzler, Dietrich; Rossaint, Rolf; Mahnken, Andreas H.; Wildberger, Joachim E.; Guenther, Rolf W.; Kuhlen, Ralf

2006-01-01

Although recruitment of atelectatic lung is a common aim in acute respiratory distress syndrome (ARDS), the effects of a recruitment maneuver have not been assessed quantitatively. By multislice spiral CT (MSCT), we analyzed the changes in lung volumes calculated from the changes in the CT values of hyperinflated (V HYP ), normally (V NORM ), poorly (V POOR ) and nonaerated (V NON ) lung in eight mechanically ventilated pigs with saline lavage-induced acute lung injury before and after a recruitment maneuver. This was compared to single slice analysis near the diaphragm. The increase in aerated lung was mainly for V POOR and the less in V NORM . Total lung volume and intrathoracic gas increased. No differences were found for tidal volumes measured by spirometry or determined by CT. The inspiratory-expiratory volume differences were not different after the recruitment maneuver in V NON (from 62±18 ml to 43±26 ml, P=0.114), and in V NORM (from 216±51 ml to 251±37 ml, P=0.102). Single slice analysis significantly underestimated the increase in normally and poorly aerated lung. Quantitative analysis of lung volumes by whole lung MSCT revealed the increase of poorly aerated lung as the main mechanism of a standard recruitment maneuver. MSCT can provide additional information as compared to single slice CT. (orig.)

Pulmonary embolism: spiral CT evaluation; Embolie pulmonaire: apport de la tomodensitometrie helicoidale

Energy Technology Data Exchange (ETDEWEB)

Senac, J.P.; Vernhet, H.; Bousquet, C.; Giron, J.; Pieuchot, P.; Durand, G.; Benezet, O.; Aubas, P. [Centre Hospitalier Universitaire, 34 - Montpellier (France)

1995-06-01

Purpose: Spiral computed tomography was compared retrospectively with digital substraction pulmonary angiography (PA) in 45 patients suspected of having acute or chronic pulmonary embolism. Materials and method : 45 patients in whom the presence of acute or chronic pulmonary embolism was suspected underwent examination by spiral CT and PA. Diagnosis of pulmonary embolism was based on the direct visualization of intraluminal clots. The study of the agreement between the two methods was based on the Kappa test. In 35 cases, pulmonary emboli were proved. Acute pulmonary emboli were present in 28 cases and chronic in 7 cases. Results: Spiral computed tomography represents an excellent way to detect acute pulmonary embolism. In the chronic form, spiral CT is better than PA to detect intraluminal clots. However, Spiral CT can fail to detect small emboli in the peripheral arterial bed. In the 10 patients without pulmonary embolism, the spiral CT proved diagnosis pulmonary oedema (n=3), lymphangi-carcinoma (n=4), pleural effusion (n=3). Conclusion: This study suggest that the spiral CT examination is accurate for diagnosis of pulmonary embolism specifically in case of suspected important embolism. The advantages of spiral CT are multiple (non invasive, wide diagnosis spectrum). However, may be a limitation to is use is insufficient distal thrombi detection. This eventuality (5 to 10% in the Pioped study) justify the practice of pulmonary angiography. Spiral CT improvements should reduce this insufficiency in the next future. (Authors). 16 refs., 4 figs., 3 tabs.

Spiral CT-angiography of the aorta

NARCIS (Netherlands)

Balm, R.; Eikelboom, B. C.; van Leeuwen, M. S.; Noordzij, J.

1994-01-01

AIMS: To determine whether the new technique of CT-angiography was accurate in displaying the complex anatomy of the aorta and its major branches. METHODS: Seventeen patients with a variety of aortic pathology were examined. Using a spiral CT-scanner a volumetric scan was made during injection of

Evaluation of computed tomography coronary angiography in patients with a high heart rate using 16-slice spiral computed tomography with 0.37-s gantry rotation time

International Nuclear Information System (INIS)

Zhang, Shi-Zheng; Hu, Xiu-Hua; Zhang, Qiao-Wei; Huang, Wen-Xin

2005-01-01

The aim of our study is to evaluate computed tomography (CT) coronary angiography in patients with a high heart rate using 16-slice spiral CT with 0.37-s gantry rotation time. We compare the image quality of patients whose heart rates were over 70 beats per minute (bpm) with that of patients whose heart rates were 70 bpm or less. Sixty patients with various heart rates underwent retrospectively ECG-gated multislice spiral CT (MSCT) coronary angiography. Two experienced observers who were blind to the heart rates of the patients evaluated all the MSCT coronary angiographic images and calculated the assessable segments. A total of 620 out of 891 (69.6%) segments were satisfactorily visualized. On average, 10.3 coronary artery segments per patient could be evaluated. In 36 patients whose heart rates were below 70 bpm [mean 62.2 bpm±5.32 (standard deviation, SD)], the number of assessable segments was 10.72±2.02 (SD). In the other 24 patients whose heart rates were above 70 bpm [mean 78.6 bpm±8.24 (SD)], the corresponding number was 9.75±1.74 (SD). No statistically significant difference was found in these two subgroups' t test, P>0.05. The new generation of 16-slice spiral CT with 0.37-s rotation time can satisfactorily evaluate the coronary arteries of patients with high heart rates (above 70 bpm, up to 102 bpm). (orig.)

Spiral CT findings of inflammatory pseudotumor of the liver

International Nuclear Information System (INIS)

Lee, Ha Jong; Nam, Kyung Jin; Lee, Ki Nam; Park, Byeong Ho; Choi, Jong Cheol; Koo, Bong Sik; Nam, Ki Dong; Kim, Chan Seong

1998-01-01

To assess the spiral CT findings of inflammatory pseudotumor of the liver(IPTL), in order to distinguish this tumor from hepatocellular carcinoma, hepatic abscess or other space occupying liver lesions. The spiral CT findings of IPTL were retrospectively evaluated in six patients. All cases were confirmed by ultrasonography-guided gun biopsy. Four patients were men and two were women, and they were aged between 37 and 74 (mean, 49) years. The site, size, and number of IPTL were assessed, and their enhancement patterns were evaluated during the arterial, portal and delayed phases of spiral CT. Five cases involved a solitary mass and in one there were multiple masses with surrounding small nodules. Four cases occurred in the right lobe and two in the left lobe. Four of five surrounding nodules were in the left lobe. During the arterial phase of spiral CT scanning, three layers were separated from four of five cases of solitary mass;they were composed of central and peripheral portions of low attenuation, and an intermediate portion of isoattenuation. Delayed enhancement of the peripheral portion was prominent during the delayed phase. In the case involving multiple masses three layers were not seen during the arterial phase, but during the delayed phase enhancement was noted. The features of three layers, as seen on spiral CT, is considered to be very specific for distinguishing IPTL from other hepatic focal lesions.=20

Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT.

Science.gov (United States)

Parsa, Azin; Ibrahim, Norliza; Hassan, Bassam; van der Stelt, Paul; Wismeijer, Daniel

2015-01-01

The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the accuracy of cone beam computed tomography (CBCT) in evaluating trabecular bone density and microstructure using MSCT and micro-CT, respectively, as reference gold standards. Twenty partially edentulous human mandibular cadavers were scanned by three types of CT modalities: MSCT (Philips, Best, the Netherlands), CBCT (3D Accuitomo 170, J Morita, Kyoto, Japan), and micro-CT (SkyScan 1173, Kontich, Belgium). Image analysis was performed using Amira (v4.1, Visage Imaging Inc., Carlsbad, CA, USA), 3Diagnosis (v5.3.1, 3diemme, Cantu, Italy), Geomagic (studio(®) 2012, Morrisville, NC, USA), and CTAn (v1.11, SkyScan). MSCT, CBCT, and micro-CT scans of each mandible were matched to select the exact region of interest (ROI). MSCT HU, micro-CT BV/TV, and CBCT gray value and bone volume fraction of each ROI were derived. Statistical analysis was performed to assess the correlations between corresponding measurement parameters. Strong correlations were observed between CBCT and MSCT density (r = 0.89) and between CBCT and micro-CT BV/TV measurements (r = 0.82). Excellent correlation was observed between MSCT HU and micro-CT BV/TV (r = 0.91). However, significant differences were found between all comparisons pairs (P micro-CT BV/TV (P = 0.147). An excellent correlation exists between bone volume fraction and bone density as assessed on micro-CT and MSCT, respectively. This suggests that bone density measurements could be used to estimate bone microstructural parameters. A strong correlation also was found between CBCT gray values and BV/TV and their gold standards, suggesting the potential of this modality in bone quality assessment at implant site. © 2013 John Wiley & Sons A/S. Published by

Three-dimensional spiral CT for neurosurgical planning.

Science.gov (United States)

Klein, H M; Bertalanffy, H; Mayfrank, L; Thron, A; Günther, R W; Gilsbach, J M

1994-08-01

We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important.

Three-dimensional spiral CT for neurosurgical planning

International Nuclear Information System (INIS)

Klein, H.M.; Bertalanffy, H.; Mayfrank, L.; Thron, A.; Guenther, R.W.; Gilsbach, J.M.

1994-01-01

We carried out 22 examinations to determine the value of three-dimensional (3D) volumetric CT (spiral CT) for planning neurosurgical procedures. All examinations were carried out on a of the first generation spiral CT. A tube model was used to investigate the influence of different parameter settings. Bolus injection of nonionic contrast medium was used when vessels or strongly enhancing tumours were to be delineated. 3D reconstructions were carried out using the integrated 3D software of the scanner. We found a table feed of 3 mm/s with a slice thickness of 2 mm and an increment of 1 mm to be suitable for most purposes. For larger regions of interest a table feed of 5 mm was the maximum which could be used without blurring of the 3D images. Particular advantages of 3D reconstructed spiral scanning were seen in the planning of approaches to the lower clivus, acquired or congenital bony abnormalities and when the relationship between vessels, tumour and bone was important. (orig.)

Added diagnostic benefit of 16-row whole-body spiral CT in patients with multiple trauma differentiated by region and injury severity according to the ATLS registered concept

International Nuclear Information System (INIS)

Maurer, M.H.; Knopke, S.; Schroeder, R.J.

2008-01-01

Purpose: to determine the added diagnostic benefit of using MS-CT in multiple trauma patients differentiated by severity of injury and affected body region. Materials and methods: a retrospective analysis was performed of the 16-row whole-body spiral CT findings in 275 multiple trauma patients (73% men, 27% women; age 39.6 ± 18.9 years) with regard to additional findings and new findings obtained with CT compared to the findings obtained by conventional projection radiography and abdominal ultrasound in the emergency room. The additional and new findings were differentiated by body region (head, face, chest, pelvis, abdomen, spine) and the degree of severity according to the three classes of injuries distinguished by the ATLS registered concept (class 1: simple injury, class 2: potentially life threatening, class 3: immediately life threatening). Results: a total of 921 additional findings (findings potentially relevant for further diagnosis and therapy in addition to the findings obtained by conventional radiography or ultrasound) were obtained by MS-CT in all patients. The distribution by number of patients and body region was as follows: 22 neck, 76 face, 125 chest, 112 abdomen, 50 pelvis, and 91 spine. Most additional findings were categorized as potentially life threatening (ATLS class 2). In addition, there were 439 completely new findings, involving the head in 128 patients (mostly ATLS class 3), the face in 18, the chest in 47, the abdomen in 26, and the spine in 9 patients. Most new findings involving the face, abdomen, and spine were ATLS class 2 injuries. (orig.)

Late-phase MSCT in the different stages of myocardial infarction: animal experiments

International Nuclear Information System (INIS)

Mahnken, Andreas H.; Bruners, Philipp; Kinzel, Sylvia; Katoh, Marcus; Muehlenbruch, Georg; Guenther, Rolf W.; Wildberger, Joachim E.

2007-01-01

The purpose of this study was to intraindividually evaluate myocardial late enhancement on multislice spiral computed tomography (MSCT) for the assessment of the different stages of myocardial infarction (MI) in comparison with magnetic resonance (MR) imaging. Reperfused MI was successfully induced in seven pigs. Delayed enhancement MR imaging and late-phase MSCT were performed on day 0 as well as 7, 28 and 90 days after the procedure. The pigs were sacrificed, and 2,3,5-triphenyltetrazolin-chloride (TTC) staining was acquired. MI size was compared between the different imaging techniques and over time applying Bland-Altman plots and multivariate analysis with repeated measures. On day 0 the mean MI size was 23.7 ± 11.8% of the left ventricular area on MSCT and 24.5 ± 10.6% on MR imaging. On day 90 infarct sizes decreased significantly to 16.9 ± 8.4% and 18.9 ± 8.0%, respectively (P 0.0019). On TTC staining the size of MI was 16.8 ± 8.2%. Bland-Altman plots showed a good agreement between MSCT and MR imaging with mean deviations ranging from -3.4% to -1.9%. No significant difference between MSCT and MR imaging was found. Myocardial late enhancement on MSCT correlates well with delayed enhancement MR imaging during the different stages of MI and allows for reliable assessment of reperfused MI during acute, subacute and chronic stages. (orig.)

Percutaneous CT-guided lung biopsy: sequential versus spiral scanning. A randomized prospective study

International Nuclear Information System (INIS)

Ghaye, B.; Dondelinger, R.F.; Dewe, W.

1999-01-01

The aim of this study was to evaluate in a prospective and randomized study spiral versus sequential scanning in the guidance of percutaneous lung biopsy. Fifty thoracic lesions occurring in 48 patients were biopsied by a senior and a junior operator. Six different time segments of the procedure were measured. Scanning mode versus length of procedure, pathological results, irradiation and complications were evaluated. Total duration of the procedure and of the first sampling was significantly longer with spiral CT for the senior operator (p < 0.004). No significant time difference was observed for the junior operator. Diameter of the lesion, depth of location, position of the patient and needle entry site did not influence the results. The sensitivity was 90.9, specificity 100, positive predictive value 100 and negative predictive value 60 % for spiral CT, and 94.7, 100, 100 and 85.7 % for sequential CT, respectively. Eleven pneumothoraces and ten perinodular hemorrhages were seen with spiral CT and six and ten, respectively, with sequential CT. The mean dose of irradiation was 4027 mAs for spiral CT and 2358 mAs for conventional CT. Spiral CT does neither reduce procedure time nor the rate of complications. Pathological results do not differ compared with sequential CT, and total dose of irradiation is higher with spiral scanning. (orig.)

The value of MSCT on prostate disease

International Nuclear Information System (INIS)

Li Xi

2009-01-01

Objective: To analyze the CT signs of BPH, and to investigate the value of diagnosis and differential diagnosis of BPH by MSCT. Methods: Multi-phase CT scanning including plain scan, arterial phase (35sec), venous phase (65sec), parenchymal phase (95sec), lag period (180sec) scan after giving contrast medium was performed in 22 cases with BPH proven pathologically and clinically. CT signs of plain scan and dynamic scan were analyzed. Results: Morphology of prostatic hyperplasia was: chestnuts like in lightly hyperplasia with normal or slightly increased volume; round in obviously hyperplasia with enlarged volume; all the hyperplasia prostate impressed to the base of bladder, even with lobulated incisure of bladder neck. Symphyso-cyst of prostate, bladder stone, bladder diverticulum, vesicocele, hydronephrosis, etc may be combined. BPH located in the central of prostate. Uniform density showed in plain scan. CT value was 35.7 ± 3.5HU; average CT value was 50.7 ± 10.4HU in arterial phase, 67.2 ± 12.3HU in venous phase, 70.1 ± 7HU in parenchymal phase and 68.8 ± 8.2HU in lag period scan, Densr-time-curve of BPH was slow-flatbed pattern. Conclusion: MSCT is of important value in diagnosis and differential diagnosis of BPH for the morphologic characteristics and development of BPH can be evaluated thoroughly by it. (authors)

The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

International Nuclear Information System (INIS)

Lei Zhen; Ma Heji; Xu Na; Xi Huanjiu

2011-01-01

Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

Energy Technology Data Exchange (ETDEWEB)

Lei Zhen, E-mail: leizhen2004@163.com [Department of Anatomy, Chinese Medical University, No. 92, Beiermalu Road, Heping District, Shenyang, 110001 (China) and Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Ma Heji, E-mail: maheji9831@sina.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xu Na, E-mail: xuna821230@sohu.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xi Huanjiu, E-mail: xihuanjiu2004@yahoo.cn [Anthropology Institute, Liaoning Medical College, No. 40, Sanduan, Songpo Rd, Jinzhou, 121001 (China)

2011-05-15

Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

Vascular imaging with spiral CT. The way to CY angiography

International Nuclear Information System (INIS)

Prokop, M.; Schaefer, C.; Kalender, W.A.; Polacin, A.; Galanski, M.

1993-01-01

Spiral CT is a technique that allows for high-quality two-dimensional angiographic projections and 3D imaging of vascular structures. The authors present the technical and methodological principles of the technique, including scan parameters and parameters of contrast application for various clinical imaging tasks. They present their experience with over 150 clinical cases using spiral CT angiography. Suitable applications of this technique include cogenital anomalies, aneurysms, dissections, stenoses, thrombi and vascular tumor involvement. Given a problem-adapted examination technique, pathologic changes in vessels of as little as 2 mm can be visualized. In some cases with complex vascular anatomy, spiral CT angiography can be superior to arterial angiography. (orig.) [de

Modelling the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner

International Nuclear Information System (INIS)

Amin, A T Mohd; Rahni, A A Abd

2017-01-01

Reconstructing large volumetric 3D images with minimal radiation dosage exposure with reduced scanning time has been one of the main objectives in the advancement of CT development. One of its advancement is the introduction of multi-slice arc detector geometry from a cone-beam source in third generation scanners. In solving this complex geometry, apart from the known vast computations in CT image reconstruction due to large CT images, iterative reconstruction methods are preferred compared to analytic methods due to its flexibility in image reconstruction. A scanner of interest that has this type of geometry is the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner , which has a total of 32 slices with 672 detector elements on each slice. In this paper, the scanner projection is modelled via the intersecting lengths between each ray (exhibited from the source to the detector elements) with the scanned image voxels, which are evaluated using the classical Siddon’s algorithm to generate the system matrix, H . This is a prerequisite to perform various iterative reconstruction methods, which involves solving the inverse problem arising from the linear equation: S = H· I; where S is the projections produced from the image, I. Due to the ‘cone-beam geometry’ along the z -axis, the effective field-of-view (FOV) with voxel dimensions (0.4×0.4×0.4) mm 3 is 512×512×32 voxels. The scanner model is demonstrated by reconstructing an image from simulated projections using the analytic Feldkamp-Davis-Kress (FDK) method against basic iterative image reconstruction methods. (paper)

Floating venous thrombi: diagnosis with spiral-CT-venography

International Nuclear Information System (INIS)

Gartenschlaeger, M.; Schmidt, J.A.

1996-01-01

Local application of contrast agent into an ipsilateral dorsal foot vein and spiral CT were used to examine 16 consecutive cases with deep venous thrombosis proven at conventional venography; in addition, colour Doppler flow imaging was performed. At conventional venography, 8/16 thrombi appeared to be floating and the remaining 8/16 were adherent to the vessel wall. Spiral-CT showed 15/16 thrombi to be adherent to the vessel wall; the floating thrombus correlated with findings in conventional venography. At colour Doppler flow imaging 3/16 thrombi were considered floating, one of them was discordant to conventional venography. The comparison of conventional venography to spiral-CT demonstrates complete agreement for adherence to vessel wall seen in conventional venography (p=1,0) and significant discordance in cases with free-floating appearance in conventional venography. Adherence of thrombi to the wall of the vessel at conventional venography is in agreement with computed tomography. Conventional venography probably overestimates the prevalence of free floating thrombi. (orig./MG) [de

Hypoxic-ischemic encephalopathy in neonates and infants: an evaluation with spiral CT

International Nuclear Information System (INIS)

Zhu Linghua

2006-01-01

Objective: To evaluate spiral CT imaging in the diagnosis of hypoxic-ischemic encephalopathy (HIE) in the neonates and infants. Methods: 112 children with history of asphyxia in peri-natal period and evident clinical symptoms were evaluated with Spiral CT. CT findings were studied. Results: 46 minor cases, 57 moderate cases and 9 severe cases were found out of 112 patients. Intracranial hemorrhage was revealed in 38 cases. Mortality occurred in 1 case. Conclusion: Spiral CT is helpful for evaluating brain damage and predicting prognosis in neonates with HIE. (authors)

Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective

International Nuclear Information System (INIS)

Mahnken, Andreas H.; Wildberger, Joachim E.; Koos, Ralf; Guenther, Rolf W.

2005-01-01

Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram-gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique

Value of noncontrast spiral CT for suspected acute appendicitis

International Nuclear Information System (INIS)

Choi, Pil Yeob; Lee, Sang Wook; Kwon, Jae Soo; Sung, Young Soon; Rho, Myoung Ho; Chang, Jeong A.

1998-01-01

To assess the diagnostic accuracy and clinical efficacy of noncontrast spiral CT in patients with suspected acute appendicitis. Over a six-month period, 100 patients with suspected acute appendicitis were prospectively evaluated with noncontrast spiral CT. All scans were obtained from the lower body of L3 to the symphysis pubis, with 5mm or 10mm collimation and pitch of 1 or 1.5, and without intravenous or oral contrast material. Diagnosis was established by means of surgical or clinical follow-up. Prospective diagnosis based on CT findings was compared with surgical results and clinical follow-up. Acute appendicitis was confirmed in 47 of 100 patients. On the basis of the Ct findings, SI patients were prospectively interpreted as positive for appendicitis, but in six the diagnosis was false-positive. Two of the 47 with acute appendicitis were prospectively interpreted as normal. The preoperative diagnosis of acute appendicitis was, thus, 45 true-positive, 47 true-negative, six false-positive and two false-negative yielding a sensitivity of 96%, a specificity of 89%, an accuracy of 92%, a positive predictive value of 88%, and a negative predictive value of 96%. Using CT, an alternative diagnosis was established in 14 patients. Noncontrast spiral CT is a useful technique for diagnosing acute appendicitis. =20

Whole-body CT. Spiral and multislice CT. 2. tot. rev. and enl. ed.; Ganzkoerper-Computertomographie. Spiral- und Multislice-CT

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Prokop, M.; Galanski, M.; Schaefer-Prokop, C.; Molen, A.J. van der

2007-07-01

Spiral and multidetector techniques have improved the diagnostic possibilities of CT, so that image analysis and interpretation have become increasingly complex. This book represents the current state of the art in CT imaging, including the most recent technical scanner developments. The second edition comprises the current state of knowledge in cT imaging. There are new chapters on image processing, application of contrasting agents and radiation dose. All organ-specific pathological findings are discussed in full. There are hints for optimum use and interpretation of CT, including CT angiography, CT colonography, CT-IVPL, and 3D imaging. There is an introduction to cardio-CT, from calcium scoring and CTA of the coronary arteries to judgement of cardiac morphology. There are detailed scan protocols with descriptions of how to go about parameter selection. Practical hints are given for better image quality and lower radiation exposure of patients, guidelines for patient preparation and complication management, and more than 1900 images in optimum RRR quality. (orig.)

Enhancement pattern of small hepatic hemangioma: findings on multiphase spiral CT and dynamic MRI

International Nuclear Information System (INIS)

Choi, Byung In; Lee, Seung Koo; Kim, Myeong Jin; Chung, Jae Joon; Yoo, Hyung Sik; Lee, Jong Tae

1999-01-01

To compare the enhancement characteristics of small hemangiomas seen on multiphase spiral CT and dynamic MR imaging. Thirteen patients with 20 hepatic hemangiomas less than 25mm in diameter underwent both multiphase spiral CT and dynamic MR imaging. All lesions were assigned to one of three classified into 3 categories according to the enhancement pattern seen on multiphase spiral CT : typical delayed pooling, atypical early enhancement, or continuous low attenuation. The enhancement patterns seen on spiral CT and on dynamic MRI were correlated. On CT scans, ten lesions (50%) showed delayed pooling. Six (30%) showed early arterial enhancement and four (20%) showed continuous low attenuation. On delayed-phase MRI, all lesions showed delayed high signal intensity compared to adjacent liver parenchyma. Four of six lesions with early enhancement on CT showed peripheral globular enhancement on early arterial-phase MRI. On multiphase spiral CT scans, small hemangiomas can show variable atypical enhancement features. In this situation, contrast-enhanced dynamic MRI is helpful for the diagnosis of hemangiomas

First results of spiral CT angiography in the evaluation of carotid artery stenosis

International Nuclear Information System (INIS)

Link, J.; Mueller-Huelsbeck, S.; Brossmann, J.; Grabener, M.; Voss, C.; Heller, M.

1995-01-01

To determine the value of spiral CT angiography in Maximum Intensity Projection (MIP)-technique for evaluation of carotid artery stenosis. A comparison of the MIP technique with intraarterial DSA was done in 24 patients with 40 stenoses. Quantification of stenosis was determined according to the NASCET study: mild (0-29%), moderate (30-69%), severe (70-99%) and occlusion (100%). Totally the correlation of spiral CT angiography with DSA was 80% (r=0.93; p=0.0001). In the moderate stenosis group (r=1; p=0.1573), severe stenosis group (r=0.89; p=0.002) and the occlusion group (r=1; p=0.0009) there was a good correlation with DSA. In the mild stenosis group (r=0.55; p=0.0704) correlation of spiral CT angiography with DSA was poor. Spiral CT angiography allows an excellent delineation of calcifications. Tandem lesions and collateral flow cannot be shown with spiral CT angiography. (orig./MG) [de

The influence factors in image quality of multi-slice spiral CT coronary angiography (MSCTA)

International Nuclear Information System (INIS)

Zeng Huiliang; Zhu Xinjin; Liang Jianhao; Zhong Yingze; Chen Xueguang; Ou Weiqian; Wen Haomao; Li Peiwen

2007-01-01

Objective: To evaluate the influence of heart rate on image quality of multi-slice spiral CT coronary angiography(MSCTA) and the optimization of image reconstruction windows. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 67 cases. The cases were divided into four groups by heart rate, groupl with heart rate less than 60 beats per minute(bpm), group 2 with heart rate 61-70 bpm, group 3 with heart rate 71-80 bpm and group 4 with heart rate over 81 bpm. The impact of heart rate on image quality of MSCTA and the optimization of image reconstruction windows were evaluated. Results: 4 coronary (RCA,LM,LAD,LCX) segments were analyzed in each patients with regard to image quality. 86.7%(112/128) of the coronary segments were sufficient for analysis in patients with heart rate less than 60 bpm,62.5%(55/88) with 61-70 bpm,40%(8/20) with 71-80 bpm and 12.5%(2/16) with heart rate over 81 bpm, respectively. There were statistically significances between every coronary segments of group 1 and 2, group 3 and 4 (P<0.05). All coronary segments of group 1 were optimally visualized on the image reconstructed at 75% image reconstruction window of' cardiac cycle; 89.5% cases at 75% in group 2; for group 3.55% of coronary artery were best presented at 75% image reconstruction window, 45% of coronary artery at 45%; All coronary segments of group 4 were optimally visualized on the image reconstructed at 45% image reconstruction window. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate. Coronary artery is usually best shown at 75% image reconstruction window of cardiac cycle for those with heart rate less than 70 bpm. 30%-90% image reconstruction should be performed when heart rate is over 71 bpm. (authors)

The value of spiral CT scan on fracture of ankle joint and tarsal bones

International Nuclear Information System (INIS)

Li Zhaoli; Liang Jingyin; Pan Zhifeng

2009-01-01

Objective: To study the value of spiral CT scan on the fracture of ankle joint and tarsal bones. Methods: 43 cases with the fracture of ankle joint and tarsal bones were collected and analyzed. All the cases were examined by plain film radiography and spiral CT thin slice scan. Multi-planar reformation (MPR), surface shaded display (SSD) and other techniques of image post-processing were performed in 35 cases of them. Results: Spiral CT scan could demonstrate more fractures than plain film radiography in 28 cases(65.1%). There are 15 cases (34.9%) which are normal in plain film radiography but abnormal in Spiral CT scan. Spiral CT could demonstrate the different length, width, direction and number of linear low density shadow. SSD and MPR were performed again in the cases with avulsion fracture and fragmental fracture to demonstrate the fracture direction and the shape, size and location of fragments more clearly. Conclusion: Spiral CT thin slice scan with image post-processing techniques can play an important role in fracture of ankle joint and tarsal bones. (authors)

Lung studies with spiral CT. pitch 1 versus pitch 2

International Nuclear Information System (INIS)

Sartoni Galloni, S.; Miceli, M.; Lipparino, M.; Burzi, M.; Gigli, F.; Rossi, M.S.; Santoli, G.; Guidarelli, G.

1999-01-01

In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality [it

Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

International Nuclear Information System (INIS)

Wang Ximing; Wu Lebin; Sun Cong; Liu Cheng; Chao, Bao-Ting; Han Bo; Zhang Yunting; Chen Haisong; Li Zhenjia

2007-01-01

Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot

Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

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Wang Ximing [Tianjin Medical University, Tianjin City (China) and Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)], E-mail: wxming369@163.com.cn; Wu Lebin [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Sun Cong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Liu Cheng [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Chao, Bao-Ting [Shandong University Medical College, Shandong Jinan 250012 (China); Han Bo [Shandong Provincial Hospital Pediatric Department, Shandong, Jinan 250021 (China); Zhang Yunting [Tianjin Medical University, General Hospital MR Department, Tianjin City (China); Chen Haisong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Li Zhenjia [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)

2007-11-15

Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

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Coche, E.E.; Hammer, F.D.; Goffette, P.P. [Dept. of Radiology, St. Luc University Hospital, Brussels (Belgium)

2001-11-01

The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

International Nuclear Information System (INIS)

Coche, E.E.; Hammer, F.D.; Goffette, P.P.

2001-01-01

The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

Measurement and analysis of cardiopulmonary vascular in Lanzhou healthy adults with multislice spiral CT

International Nuclear Information System (INIS)

Shi Xiaonan; Guo Shunlin

2013-01-01

Objective: To constitute a normal standard of cardiopulmonary vascular diameter and size of normal adult in Lanzhou, and to compared with the other's data reported in the previous bibliography by measuring diameter and area of cardiopulmonary artery lumen of the healthy adults in Lanzhou with multislice spiral CT (MSCT). Methods: Three hundred Lanzhou adults with no cardiopulmonary disease were equally assigned to 3 groups according to their age (A group: 18-39 years, B group: 40-60 years, C group: 61-80 years; 50 females and 50 males in each group). CT data were acquired at the end of deep inspiration phase and measurements were done on 3D reconstruction image with precise landmarks. All the results were statistically analyzed. Results: The diameters and areas of the main pulmonary artery left pulmonary artery right pulmonary artery ascending aorta and descending aorta differed significantly among the 3 groups (P<0.05). In groups B and C, there were significant differences in diameters and areas of pulmonary artery left pulmonary artery and right pulmonary between different genders (P<0.05). Conclusion: Imaging standard is provided for Lanzhou adult in early diagnosis of cardiopulmonary disease. The diameters and areas of main pulmonary artery left pulmonary artery and right pulmonary artery of Lanzhou healthy adults are different from that of other regions. It may be related to the geographical environment and the state of air pollution in Lanzhou. (authors)

Measurement of total lung capacity : a comparison of spiral CT and spirometry

International Nuclear Information System (INIS)

Chung, Kyung Il; Park, Kyung Ju; Lee, Eh Hyung; Yune, Heun Young; Suh, Jung Ho; Choe, Kyu Ok; Lim, Tae Hwan; Chung, In Hyuk

1996-01-01

To determine the potential of spiral CT as a functional imaging modality of the lung aside from its proven value in morphological depiction. Spiral CT scan was performed in ten normal female and nine normal male adults (mean age: 39, height: 163 cm, weight: 62 kg ) after single full breath-holding. Three dimensional lung images were reconstructed(minimal threshold value: -1,000HU, maximal threshold values: -150, 250, -350, -450 HU) to obtain total lung volume(TLV) on a histogram. Total lung volume measured by spiral CT was compared with TLV obtained by spirometry. Mean TLV measured by spirometry was 5.62L and TLV measured by CT at maximal threshold values of -150, -250, -350, and -450 HU was 5.53, 5.33, 5.15, and 4.98L, respectively. Mean absolute differences between the modalities of 0.17L(3%), 0.32L(5.6%), 0.48L(8.5%), 0.65L(11.5%) were statistically significant(p<0.001). Linear regression coefficients between the modalities were 0.99, 0.97, 095, and 0.94 and no statistically significant differences in accuracy of threshold levels in the estimation of lung volume(r=0.99, standard error=0.034L in all) were seen. TLV measured by spiral CT closely approximated that measured by spirometry. Spiral CT may be useful as a means of evaluating lung function

Relationship of radiation dose and spiral pitch for multi-slice CT system

International Nuclear Information System (INIS)

Song Shaojuan; Wang Wei; Liu Chuanya

2006-01-01

Objective: To study the relations of radiation dose and spiral pitch for multi-slice CT system. Methods: 16 mm dose phantom with solidose 300/400 pen-style ion chamber inserted into each of five holes in turn was scanned with different spiral pitch by LightSpeed 16-slice CT and Sensation 16-slice and 64-slice CT and radiation dose. Results: CTDI vol of axial scan and spiral scan for the three types of CT system are: (1) LightSpeed 16-slice CT: 28.9 (axial), 51.4 (pitch 0.562), 30.8 (pitch 0.938) and 16.5 ( pitch 1.75 ); (2) Sensation 16-slice CT: 41.2(axial) and 40.3(pitch 0.5) ,41.5(pitch 1) and 43.2(pitch 1.5); (3) Sensation 64- slice CT: 41.2(axial) and 40.3(pitch 0.5),41.5(pitch 1),43.2(pitch 1.5). Conclusions: For LightSpeed 16-slice CT, the measured radiation dose decreased with the increase of spiral pitch, the image quality could keep constant only if we increase mAs. While for Sensation 16-slice and 64-slice CT system, the measured radiation dose was identical for different pitch, and the image quality was identical because of the use of mAs auto control technique The mAs should be adjusted in different way according to the type of CT system when the pitch is changed in daily operation. (authors)

Enhanced dual-phase spiral CT features of polypoid ampullary carcinoma

International Nuclear Information System (INIS)

Zeng Mengsu; Yan Fuhua; Zhou Kangrong; Chen Huiming; Chen Gang; Chen Jin

2001-01-01

Objective: To understand CT features of polypoid ampullary carcinoma by enhanced dual-phase spiral CT. Methods: 15 cases of polypoid ampullary carcinoma (PAC) confirmed by surgical and pathological results were studied with thin slice enhanced dual-phase spiral CT (including arterial and portal phase scanning)with retrospective analysis, the scanning parameters were 5 mm thickness and 1.0 pitch for arterial phase scanning, and 5 mm thickness and 5 mm space for portal phase scanning. Results: All cases could display an enhanced mass as local filling defect at the site of the duodenal Vater's ampulla during arterial and portal phase scanning, the tumors ranged in size from 1 cm to 5 cm with mean of 2.3 cm, all were accompanied with dilated intrahepatic and common bile duct, enlarged gallbladder and dilated pancreatic duct, except one case which had marked atrophy of the pancreatic body and tail. Conclusion: The thin slices enhanced dual-phase spiral CT could not only accurately define the level of obstruction, but also demonstrate an enhanced mass as direct CT sign of the PAC, which is crucial for diagnosis of the PAC

MSCT versus CBCT: evaluation of high-resolution acquisition modes for dento-maxillary and skull-base imaging

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Dillenseger, Jean-Philippe; Goetz, Christian [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Matern, Jean-Francois [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Gros, Catherine-Isabelle; Bornert, Fabien [Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Universite de Strasbourg, Faculte de Chirurgie Dentaire, Strasbourg (France); Le Minor, Jean-Marie [Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Universite de Strasbourg, Institut d' Anatomie Normale, Strasbourg (France); Constantinesco, Andre [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Choquet, Philippe [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Hopital de Hautepierre, Imagerie Preclinique, Biophysique et Medecine Nucleaire, Strasbourg Cedex (France)

2014-09-24

Our aim was to conduct a quantitative and qualitative evaluation of high-resolution skull-bone imaging for dentistry and otolaryngology using different architectures of recent X-ray computed tomography systems. Three multi-slice computed tomography (MSCT) systems and one Cone-beam computed tomography (CBCT) system were used in this study. All apparatuses were tested with installed acquisition modes and proprietary reconstruction software enabling high-resolution bone imaging. Quantitative analyses were performed with small fields of view with the preclinical vmCT phantom, which permits to measure spatial resolution, geometrical accuracy, linearity and homogeneity. Ten operators performed visual qualitative analyses on the vmCT phantom images, and on dry human skull images. Quantitative analysis showed no significant differences between protocols in terms of linearity and geometric accuracy. All MSCT systems present a better homogeneity than the CBCT. Both quantitative and visual analyses demonstrate that CBCT acquisitions are not better than the collimated helical MSCT mode. Our results demonstrate that current high-resolution MSCT protocols could exceed the performance of a previous generation CBCT system for spatial resolution and image homogeneity. (orig.)

MSCT versus CBCT: evaluation of high-resolution acquisition modes for dento-maxillary and skull-base imaging

International Nuclear Information System (INIS)

Dillenseger, Jean-Philippe; Goetz, Christian; Matern, Jean-Francois; Gros, Catherine-Isabelle; Bornert, Fabien; Le Minor, Jean-Marie; Constantinesco, Andre; Choquet, Philippe

2015-01-01

Our aim was to conduct a quantitative and qualitative evaluation of high-resolution skull-bone imaging for dentistry and otolaryngology using different architectures of recent X-ray computed tomography systems. Three multi-slice computed tomography (MSCT) systems and one Cone-beam computed tomography (CBCT) system were used in this study. All apparatuses were tested with installed acquisition modes and proprietary reconstruction software enabling high-resolution bone imaging. Quantitative analyses were performed with small fields of view with the preclinical vmCT phantom, which permits to measure spatial resolution, geometrical accuracy, linearity and homogeneity. Ten operators performed visual qualitative analyses on the vmCT phantom images, and on dry human skull images. Quantitative analysis showed no significant differences between protocols in terms of linearity and geometric accuracy. All MSCT systems present a better homogeneity than the CBCT. Both quantitative and visual analyses demonstrate that CBCT acquisitions are not better than the collimated helical MSCT mode. Our results demonstrate that current high-resolution MSCT protocols could exceed the performance of a previous generation CBCT system for spatial resolution and image homogeneity. (orig.)

The role of spiral CT in pelvic trauma management

International Nuclear Information System (INIS)

Cheung, E.C.F.; Fung, K.K.L.

1999-01-01

Rapid and accurate assessment of pelvic injury is critical for good patient management. Plain X-ray is often used as a preliminary evaluation of the injury but this may not give adequate diagnosis of the acetabulum fracture, subtle fracture of the pelvic bone and the associated soft tissue injuries. Nowadays, spiral CT has taken an increasing role in the evaluation of pelvic trauma. It gives a rapid assessment of the bone and soft tissue injuries as compared to conventional CT. Besides, 2-D (multiplanar imaging) and 3-D image reconstruction with multiple angle views, provide the maximum information which facilitates detailed pelvic trauma evaluation. Three cases were used to illustrate the role of spiral CT in pelvic trauma management. Copyright (1999) Blackwell Science Pty Ltd

Measurement of slice sensitivity profile for a 64-slice spiral CT system

International Nuclear Information System (INIS)

Liu Chuanya; Qin Weichang; Wang Wei; Lu Chuanyou

2006-01-01

Objective: To measure and evaluate slice sensitivity profile (SSP) and the full width at half-maximum(FWHM) for a 64-slice spiral CT system. Methods: Using the same CT technique and body mode as those used for clinical CT, delta phantom was scanned with Somatom Sensation 64-slice spiral CT. SSPs and FWHM were measured both with reconstruction slice width of 0.6 mm at pitch=0.50, 0.75, 1.00, 1.25, 1.50 and with reconstruction slice width of 0.6, 1.0, 1.5 mm at pitch=1 respectively. Results: For normal slice width of 0. 6 mm, the measured FWHM, i.e. effective slice width, is 0.67, 0.67, 0.66, 0.69, 0.69 mm at different pitch. All the measured FWHM deviate less than 0.1 mm from the nominal slice width. The measured SSPs are symmetrical, bell-shaped curves without far-reaching tails, and show only slight variations as a function of the spiral pitch. When reconstruction slice width increase, relative SSP become wider. Conclusions: The variation of pitch hardly has effect all on SSP, effective slice width, and z-direction spatial resolution for Sensation 64-slice spiral CT system, which is helpful to optimize CT scanning protocol. (authors)

Comparative analysis of multi-slice spiral CT and positron emission tomography-CT in evaluation of axillary lymph nodes in breast cancer patients

International Nuclear Information System (INIS)

Sun Xianchang; Zhang Ruyi; Liu Qingwei; Zhao Suhong; Zu Degui; Li Xin

2008-01-01

Objective: To evaluate and compare spiral CT and positron emission tomography-CT (PET-CT) in characterization of of axillary lymph nodes in breast cancer patients. Methods: Forty patients with pathologically proven breast cancer underwent contrast-enhanced spiral CT of the breast and axilla, 13 of them also underwent PET-CT examination. One hundred and fifty-eight axillary lymph nodes were found in the 40 patients through contrast enhanced spiral CT, while 57 lymph nodes were found in the 13 patients through PET-CT. Three radiologists rated the lymph nodes found in CT images on a five-point scale. If the score was equal to or greater than 3, it was defined as positive (metastatic), otherwise negative. Visual observation and semiquantitative analysis were used to classify lymph nodes in PET-CT images. The results of spiral CT observation and PET-CT observation of lymph nodes were compared with pathological results. The relative value of CT and PET-CT was analyzed. Exact probability statistics were employed. Results: One hundred and fifty eight lymph nodes of 40 patients were detected by spiral CT, 91 of them were diagnosed as positive and 67 as negative Among the lymph nodes found in spiral CT, 99 were positive and 59 were negative pathologicall. A total of 57 lymph nodes were found by PET-CT. Thirty-nine of them were defined as positive and 18 as negative. Among the lymph nodes found in PET-CT, 39 were positive and 18 were negative pathologically. The sensitivity, specificity, accuracy, positive and negative predictive values in CT prediction in axillary lymph nodes metastases were 88.89%, 94.91%, 91.14%, 96.70%, and 83.58%, respectively. The sensitivity, specificity, accuracy, positive and negative predictive values in PET-CT prediction in axillary lymph nodes metastases were 97.44%, 94.44%, 96.49%, 97.44%, and 94.44%, respectively. PET-CT had no significant difference with spiral CT in sensitivity, accuracy, positive and negative predictive values for detection

Improvement in printing technique of spiral CT three-dimensional colour image

International Nuclear Information System (INIS)

Wang Yicheng; Liu Feng; Zhang Ling

2005-01-01

Objective: To investigate the printing technique of spiral CT three-dimensional (3D) colour image. Methods: The 3D colour images of 136 patients were printed, with the equipment of Marconi spiral CT, personnel computer, colour ink printer, and network switchboard. Results: All printed images were satisfied by this method. Conclusion: This technique is economic, simple, and useful, and can meet the need for clinical diagnosis and operation. (authors)

Evaluation of recent curative effect of chemotherapy on hepatocellular carcinoma with MSCT

International Nuclear Information System (INIS)

Zhao Jing; Zheng Keguo

2009-01-01

Objective: To study the value of MSCT in evaluating the recent curative effect of hepatocellular carcinoma (HCC) after the chemotherapy with Oxaliplatin combined with 5-FU and Folinic Acid. Methods: 6 cases with HCC or post hepatectomy metastasis HCC confirmed by pathohistology underwent chemotherapy with Oxaliplatin combined with 5-FU and Folinic Acid. MultiSpiral Computed Tomography was used to determine the target lesions before and after the chemotherapy. The size of the target lesions before the chemotherapy was refer as the basic value (x0), and that after the chemotherapy was regarded as the observed value (y1). The theoretic value was obtained based on tumor growth dynamics mathematic model y2(x)=X 0 2 t/3td . Results: Before and after the first chemotherapy or between the consecutive chemotherapy cycles, the target lesions could be follow-up one by one with MSCT. There was significant statistical difference between observed increase size and theoretical increase size, P=0.0442. Conclusion: Tumor growth velocity can be effectively controlled with this chemotherapy plan, and MSCT may used to be an objective tool to evaluate the recent curative effect of chemotherapy on hepatocellular carcinoma. (authors)

Initial clinical experience with spiral CT angiography in the abdomen

International Nuclear Information System (INIS)

Gaa, J.; Stehling, M.K.; Costello, P.

1993-01-01

The latest developments in modern CT instruments, offering scanning times of a second, opened up new possibilities in CT imaging in combination with the spiral technique. The data set normally taken with single-breath-hold technique is free of respiratory artefacts and thus is a good basis for accurate 3D image reconstruction. Spiral CTA allows a non-invasive 3D imaging of various blood vessels. Patients with abdominal aortic aneurysms of aorto-iliac bypass can be examined as outpatients within 15 minutes. (orig.) [de

Correlation between Podoplanin-positive Lymphatic Microvessel Density 
and CT Characteristics of Non-small Cell Lung Cancer

Directory of Open Access Journals (Sweden)

Hui ZHOU

2012-01-01

Full Text Available Background and objective It has been proven that ymphatic microvessel density (LMVD was closely correlated with the lymphatic metastasis of non-small cell lung cancer (NSCLC. The aim of the present study is to explore the relationship between podoplanin-LMVD and multi-slice spiral computed tomography (MSCT characteristics of NSCLC. Methods MSCT scanning was performed on 34 cases of NSCLC (squamous carcinoma, 15 cases; adenocarcinoma, 15 cases; and adenosquamous carcinoma, 4 cases prior to operation. Clinical pathology results, including lymph node metastasis, were obtained. CT characteristics, such as shape of the edge, internal structure, and adjacent structures, were described. LMVD in the central and peripheral areas examined respectively using SP immunohistochemical technique were analyzed. Results Lymph node metastasis was found to be associated with LMVD in the peripheral areas. LMVD in the peripheral areas of the resected lesions, the MSCT findings of which included spinous process, pleural indentation, and carcinomatous lymphangitis, was higher than that of the lesions without these MSCT characteristics (P<0.05. Conclusion MSCT findings of spinous process, pleural indentation, or carcinomatous lymphangitis of NSCLC may suggest a higher level of tumor lymphangiogenesis with a higher risk of lymph node metastasis.

Spiral CT scanning plan to generate accurate Fe models of the human femur

International Nuclear Information System (INIS)

Zannoni, C.; Testi, D.; Capello, A.

1999-01-01

In spiral computed tomography (CT), source rotation, patient translation, and data acquisition are continuously conducted. Settings of the detector collimation and the table increment affect the image quality in terms of spatial and contrast resolution. This study assessed and measured the efficacy of spiral CT in those applications where the accurate reconstruction of bone morphology is critical: custom made prosthesis design or three dimensional modelling of the mechanical behaviour of long bones. Results show that conventional CT grants the highest accuracy. Spiral CT with D=5 mm and P=1,5 in the regions where the morphology is more regular, slightly degrades the image quality but allows to acquire at comparable cost an higher number of images increasing the longitudinal resolution of the acquired data set. (author)

MSCT multi-criteria: A novel approach in assessment of mediastinal lymph node metastases in non-small cell lung cancer

International Nuclear Information System (INIS)

Volterrani, Luca; Mazzei, Maria Antonietta; Banchi, Benedetta; Voltolini, Luca; La Sala, Filomena; Carbone, Salvatore Francesco; Ricci, Veronica; Gotti, Giuseppe; Zompatori, Maurizio

2011-01-01

Summary: Purpose: To evaluate the accuracy of multi-slice computed tomography (MSCT) in diagnosing mediastinal lymph node metastases in patients with non-small cell lung cancer (NSCLC) using a multi-criteria approach. Methods: We retrospectively reviewed contrast-enhanced MSCT of the chest in 86 consecutive patients with histopathologically proven NSCLC. All patients underwent surgical lymph node resection within 30 days from the CT examination. In all cases pathological and CT results were reviewed and correlated. Results: The sensitivity, specificity, positive and negative predictive values, and accuracy of MSCT using a multi-criteria approach in the detection of the N2 stage were 100%, 98.5%, 100%, 94.4% and 98.8% respectively, whereas using the size criterion alone 64%, 61%, 87%, 40%, and 62% respectively. Conclusions: To improve MSCT accuracy for diagnosing N staging other criteria can be associated with lymph node size. The use of different dimensional cut-offs for each mediastinal lymph node station, the matching of positive nodal stations with tumour location, the structural characteristics and the type of enhancement allow for a high accuracy of MSCT in the staging of mediastinal nodes in NSCLC.

Comparative analysis between spiral CT and pathology of pulmonary nodules

International Nuclear Information System (INIS)

Wang Kaifu; Zhang Zhanqing

2007-01-01

Objective: To explore the value of spiral CT in the diagnosis of atypical pulmonary nodules. Methods: CT, clinic and histopathologic data of 72 patients with atypical pulmonary nodules confirmed by surgical resection in 41 cases and/or biopsy in 31 cases were retrospectively analyzed. Results: CT scans demonstrated slight lobulation in 34 cases, irregular margin in 50 cases, long speculate in 10 cases, air-bronchogram in 2 case, vacuole in 2 case. 38 pulmonary cancer, 22 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were diagnosed with spiral CT. However, 30 pulmonary cancer, 30 pulmonary tuberculosis and 12 pulmonary inflammatory pseudotumors were confirmed by histopathology. The overall accurate diagnostic rate of pulmonary cancer was 66.7% (20/30), pulmonary tuberculosis was 60%(18/30), pulmonary inflammatory pseudotumors was 16.7%(2/12). 40 cases were diagnosed correctly and 32 cases were misdiagnosed with CT in 72 cases of atypical pulmonary nodules. The misdiagnostic rate of CT was 44.4%. 10 cases of lung cancer were misdiagnosed, including 4 cases of tuberculosis (long speculate or irregular margin) and 6 cases of inflammatory pseudotumors (irregular margin or long speculate or air-bronchogram). 12 cases of tuberculosis were misdiagnosed, including 8 cases lung cancer (slight lobulation) and 4 cases of inflammatory pseudotumors (slight lobulation). 10 cases inflammatory pseudotumor were misdiagnosed as lung cancer (slight lobulation). Conclusion: Spiral CT was very useful in the localization and morphological describing, but difficult in qualitative diagnosing of atypical pulmonary nodules, exactly diagnosis was relied on surgery and biopsy. (authors)

[Significance and mechanism of MSCT perfusion scan on differentiation of NSCLC].

Science.gov (United States)

Liu, Jin-Kang; Hu, Cheng-Ping; Zhou, Mo-Ling; Zhou, Hui; Xiong, Zeng; Xia, Yu; Chen, Wei

2009-06-01

To determine the significance of MSCT perfusion scan on differentiation of NSCLC and to investigate its possible mechanisms. Forty four NSCLC patients underwent CT perfusion scan by MSCT. Among them, 22 cases were selected to detected the two-dimensional tumor microvascular architecture phenotype (2D-TMAP), the relationships between CT perfusion parameters (BF, BV, PEI, TIP), and the differentiation of NSCLC were analysed by using the correlation analysis and trend test. Spearman correlation analysis was used to study the relationships between CT perfusion parameters, differentiation, and 2D-TMAP. The total BF, BV and PEI decreased with decreasing differentiation of NSCLC (P<0.05). The total PEI showed a positive correlation with the total MVD (P<0.05). There were negative correlations between the surrounding area BF, the total BF, BV, and PEI, the uncomplete lumen of the surrounding area MVD, and expression of PCNA, respectively (P<0.05). There were positive correlations between degree of differentiation and the uncomplete lumen of the surrounding area MVD (P<0.05). It was the same as degree of differentiation and expression of PCNA, VEGF, respectively. There were positive correlations between the uncomplete lumen of the surrounding area MVD and expression of VEGF, ephrinB2, EphB4, and PCNA, respectively (P<0.05). Perfusion parameters reflect the difference of density of vassels with mature functional lumen. Careful evaluation of the differences of blood flow pattern in pulmonary space-occupying lesions by MSCT perfusion scan can be used to identify the degree of NSCLC differentiation.

Analysis on the value of the multi-slice spiral CT and MRI scanning for applying to the identifying diagnosis of the new and old vertebral compresion fracture

International Nuclear Information System (INIS)

Huo Zhiyi; Gao Shuming; Li Dasheng; Pei Lijun; Qu Hui

2008-01-01

Objective: To analyze and explore the value of the mutislice spiral CT (MSCT) scanning, its reconstructive technology and MRI scanning for applying to the identifying diagnosis of new and old vertebral compresion fracture. Methods: One hundred and sixty-seven cases with the new and old vertebral compresion fracture who have 189 vertebrae in total were examined using the MSCT scanning, their imaging information were postprocessed with 2D and 3D reconstruction at the work station. Thirty-four patients with overall 43 vertebrae were carried out by MRI scanning and their images were compared with those of MSCT. Results: They had the highest proportion of vertebrae in L1 with accounting for 27.68% (31/112) and 35.06% (27/77) among the patients with new and old vertebral compresion fracture, respectively. The next was T12, L2 and T11. There were statistically significant differences between new and old cases in such appearance as fracture line clear and sharp (102 and 21), contusion and hemorrhage of spinal cord (15 and 0), parenchyma shadow beside vertebrae(103 and 11), appendant fracture(26 and 5), organ's lacerated wound around vertebral body (30 and 0), discus intervertebrales vacuum (10 and 36), derangement and hardening of vertebral bone trabecularism (29 and 51) (P 1 WI signal, 27 vertebrae with the T 2 WI fat-suppresion irregular high signal were demonstrated in MRI scanning among 27 vertebrae of 21 cases with new vertebral compresion fracture. While 16 vertebrae with the T 1 WI and T 2 WI signals were the same as those of the normal vertebrae, 16 vertebrae were the T 2 WI fat-suppresion low signal among 13 cases with old vertebral compresion fracture. Conclusions: The MSCT plays an important role in identifying diagnosis for the most of the patients with the new and old vertebral compresion fracture, while MRI scanning may reflect the pathophysiological characteristics in diagnosis of the spinal cord and the ligament lesion. Therefore, the MSCT and MRI scanning

Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

International Nuclear Information System (INIS)

Hou Yang; Guo Wenli; Yue Yong; Chen Liying; Guo Qiyong; Yu Xianyi; Wang Hong

2006-01-01

Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

Three phase dynamic CT with double spiral CT: utility of determination of stomach cancer stage

International Nuclear Information System (INIS)

Jung, Min Ha; Kim, Hong In; Kim, Tae Hyung; Lee, Ki Yeol; Cho, June Il; Park, Cheol Min; Cha, In Ho

1997-01-01

To evaluate the utility of three phases of spiral CT in the diagnosis of stomach cancer. Between August 1994 and March 1995, thirty eight patients with stomach cancer, demonstrated on spiral CT, underwent surgery. Twenty-eight cases were advanced and ten were early. There were 27 men, and 11 women, and their average age was 52.8 years old (33-77). After ingestion of 600-700ml of water, 120-140ml of nonionic contrast material was injected intravenously. Spiral CT scanning was performed in 10mm slice thickness and of 10mm/sec table speed. Three phase image were obtained at 25sec (arterial phase), 60-65sec (venous phase) and 4min (equilibrium phase) after the start of bolus injection. On each phase, CT findings were compared with pathologic results, and tumor detectibility, depth of tumor invasion and lymph node metastasis was analysed. Thirty of the 38 carcinomas (79%) were detected on the arterial phase, 33 (81%) on the venous phase and 30 (79%) on the equilibrium phase. Depth of tumor invasion was measured accurately in 27 of 38 cases (71%) : T1-4/10 (40%), T2-8/11 (73%), T3-13/15 (87%), T4-2/2 (100%). We overstaged one case of T1 as T2 and two cases of T2 as T3, and understaged one case of T2 as T1 and two cases of T3 as T2. Among the 16 enlarged lymph nodes larger than 8mm, 13 cases were positive on pathologic examination and the sensitivity was 65%. With three-phase spiral CT scanning, we obtained 71% accuracy of depth of tumor invasion. The venous phase is most useful for tumor detection and for determining depth of tumor invasion and lymph node metastasis

Design of wireless data transmission system for spiral CT

International Nuclear Information System (INIS)

Wang Jue; Wang Fuquan; Liu Huaili

2010-01-01

A new wireless data transmission scheme based on UWB was proposed after studying the structure and character of spiral CT transmission system, the system was designed and validated. Using UWB device as wireless module to realize wireless data transmission. Using FPGA as main controller to meet the requirement of timing control for system module. Using two pieces of SDRAM in pingpang operation to realize large capacity storage mechanism. Using USB 2.0 interface to realize high-speed connection with UWB module. The results show that the transmission speed of the system arrival at 16.87 M bit ps within 3 meters, and the precision is 100%, it can be used for line-array spiral CT. (authors)

[Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

Science.gov (United States)

Kirchner, J; Laufer, U; Jendreck, M; Kickuth, R; Schilling, E M; Liermann, D

2000-01-01

Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

Staging of gastric adenocarcinoma using two-phase spiral CT: correlation with pathologic staging

International Nuclear Information System (INIS)

Seo, Tae Seok; Lee, Dong Ho; Ko, Young Tae; Lim, Joo Won

1998-01-01

To correlate the preoperative staging of gastric adenocarcinoma using two-phase spiral CT with pathologic staging. One hundred and eighty patients with gastric cancers confirmed during surgery underwent two-phase spiral CT, and were evaluated retrospectively. CT scans were obtained in the prone position after ingestion of water. Scans were performed 35 and 80 seconds after the start of infusion of 120mL of non-ionic contrast material with the speed of 3mL/sec. Five mm collimation, 7mm/sec table feed and 5mm reconstruction interval were used. T-and N-stage were determined using spiral CT images, without knowledge of the pathologic results. Pathologic staging was later compared with CT staging. Pathologic T-stage was T1 in 70 cases(38.9%), T2 in 33(18.3%), T3 in 73(40.6%), and T4 in 4(2.2%). Type-I or IIa elevated lesions accouted for 10 of 70 T1 cases(14.3%) and flat or depressed lesions(type IIb, IIc, or III) for 60(85.7%). Pathologic N-stage was NO in 85 cases(47.2%), N1 in 42(23.3%), N2 in 31(17.2%), and N3 in 22(12,2%). The detection rate of early gastric cancer using two-phase spiral CT was 100.0%(10 of 10 cases) among elevated lesions and 78.3%(47 of 60 cases) among flat or depressed lesions. With regard to T-stage, there was good correlation between CT image and pathology in 86 of 180 cases(47.8%). Overstaging occurred in 23.3%(42 of 180 cases) and understaging in 28.9%(52 of 180 cases). With regard to N-stage, good correlation between CT image and pathology was noted in 94 of 180 cases(52.2%). The rate of understaging(31.7%, 57 of 180 cases) was higher than that of overstaging(16.1%, 29 of 180 cases)(p<0.001). The detection rate of early gastric cancer using two-phase spiral CT was 81.4%, and there was no significant difference in detectability between elevated and depressed lesions. Two-phase spiral CT for determing the T-and N-stage of gastric cancer was not effective;it was accurate in abont 50% of cases understaging tended to occur.=20

Virtual gastroscopy using spiral CT in gastric lesions

International Nuclear Information System (INIS)

Shin, Sang Soo; Kang, Heoung Keun; Jeong, Yong Yeon; Yoon, Man Won; Song, Sang Gook; Jeong, Gwang Woo

1998-01-01

To compare virtual gastroscopy using spiral CT with conventional endoscopy for the detection and evaluation of gastric lesions. During a previous six-month period, 30 patients with pathologically-proven gastric lesions underwent conventional endoscopy and virtual gastroscopy using spiral CT. There were 18 cases of advanced gastric carcinoma, eight benign ulcers, and four submucosal tumors(two leiomyomas, two lymphomas). Source images of virtual gastroscopy were three-dim-ensionally reconstructed within an Advantage Windows Workstation and virtual gastroscopic images were obtained using Navigator Software. On analysis, images were graded according to their quality(excellent, good, poor). Virtual gastroscopic images were interpreted by two radiologists blinded to conventional endoscopic findings, and were subsequently compared with endoscopic findings in terms of detectability and findings. In the cases of advanced gastric carcinoma, lesions were classified according to Borrmann's system. For virtual gastroscopy, overall image quality was excellent in 21 cases(70%), good in five(17%), and poor in four(13%). Lesions were detected in 25 cases(83%). Among the 18 advanced gastric carcinomas, virtual gastroscopy image quality was excellent in 14 cases(78%), good in two(11%), and poor in two(11%). Lesions were detected in 16 cases(89%). Two Borrmann type IV cases were not detected. Among the eight benign ulcers, virtual gastroscopy image quality was excellent in three cases(38%), good in three(38%), and poor in two(25%). The detection of lesion was possible in five cases(63%). In all submucosal tumors, virtual gastroscopy image quality was excellent. Lesions were detected in all cases. Virtual gastroscopy using spiral CT is safe and noninvasive, and for the evaluation of gastric lesions may be complementary to axial CT. It successfully detects gastric lesions, and in depicting the pattern of gastric folds its image quality is excellent.=20

Intra-individual diagnostic image quality and organ-specific-radiation dose comparison between spiral cCT with iterative image reconstruction and z-axis automated tube current modulation and sequential cCT

International Nuclear Information System (INIS)

Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Gawlitza, Joshua; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Groden, Christoph; Henzler, Thomas

2016-01-01

•Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose.•Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT.•State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. Superiority of spiral versus sequential cCT in image quality and organ-specific-radiation dose. Spiral cCT: lower organ-specific-radiation-dose in eye lense compared to tilted sequential cCT. State-of-the-art IR spiral cCT techniques has significant advantages over sequential cCT techniques. To prospectively evaluate image quality and organ-specific-radiation dose of spiral cranial CT (cCT) combined with automated tube current modulation (ATCM) and iterative image reconstruction (IR) in comparison to sequential tilted cCT reconstructed with filtered back projection (FBP) without ATCM. 31 patients with a previous performed tilted non-contrast enhanced sequential cCT aquisition on a 4-slice CT system with only FBP reconstruction and no ATCM were prospectively enrolled in this study for a clinical indicated cCT scan. All spiral cCT examinations were performed on a 3rd generation dual-source CT system using ATCM in z-axis direction. Images were reconstructed using both, FBP and IR (level 1–5). A Monte-Carlo-simulation-based analysis was used to compare organ-specific-radiation dose. Subjective image quality for various anatomic structures was evaluated using a 4-point Likert-scale and objective image quality was evaluated by comparing signal-to-noise ratios (SNR). Spiral cCT led to a significantly lower (p < 0.05) organ-specific-radiation dose in all targets including eye lense. Subjective image quality of spiral cCT datasets with an IR reconstruction level 5 was rated significantly higher compared to the sequential cCT acquisitions (p < 0.0001). Consecutive mean SNR was significantly higher in all spiral datasets (FBP, IR 1–5) when compared to sequential cCT with a mean

In-vitro studies to determine the degree of stenosis using spiral-CT angiography

International Nuclear Information System (INIS)

Wittenberg, G.; Lenk, G.; Jenett, M.; Elsner, H.; Kaiser, W.A.; Kellner, M.; Schultz, G.; Trusen, A.; Hahn, D.

1998-01-01

Purpose: Aim of the study was to evaluate the influence of different spiral-CT parameters for the visualisation of vascular stenoses, especially of the renal arteries. Material and methods: Models with a density equivalent to that of fat, filled with diluted contrast agent, and an inner lumen of 4, 6, 8 mm were scanned in x-, y- and z-direction. Data were acquired in up to 24 second long spiral-CT scans using different spiral-CT parameters (collimation, table speed, reconstruction algorithm, tube current). Detection of the degree of stenosis was achieved by assessment of the axial images and 3D reconstructions. Results: The best correlation between real and measured degree of stenosis was seen by using a small collimation, a low table increment and assessment of the axial images reconstructed in standard algorithm. The stenosis degrees of models directed in x- and y-direction were overestimated and those in z-direction were underestimated depending on the spiral-CT parameters. Conclusion: For optimal imaging of renal artery stenoses, collimation of 2 mm (pitch=1-2) and a reconstruction interval of 1 mm is recommended. (orig.) [de

The value of spiral CT thin imaging reconstruction in the diagnosis of obstructive jaundice

International Nuclear Information System (INIS)

Huang Zhi; Liu Zhang; Yang Chaoxiang; Lin Chengye; Zhang Li; Li Yuxiang; Ma Yunyan; Xiao Haisong; Lu Zhifeng; Wang Bo; Zhou Yunhong

2009-01-01

Objective: To approach the value of spiral CT thin imaging reconstruction in the diagnosis of obstructive jaundice in order to improve the correctness of the diagnosis. Methods: Analysis the cases' clinical manifestation and the CT images, who were diagnosed as obstructive jaundice by operation. All of cases had high-resolution computed tomograyhy scan. The thickness and the interval is 5mm, reconstructed the thickness and the interval to 1 mm and 1.5 mm, then send the images to the workstation and MRR were processed. Analysis the date with the pathology. Results: Spiral CT thin imaging reconstruction have 98% and 93% in the accuracy of location and characterization in the obstruction. Conclusion: The spiral CT thin imaging reconstruction is a good method to improve the accuracy of location and characterization in the obstructive jaundice. (authors)

Multi-slice spiral CT diagnosis of arterial sequestration

International Nuclear Information System (INIS)

Yu Hong; Li Huimin; Liu Shiyuan; Xiao Xiangsheng

2010-01-01

Objective: The purpose of this study was to present the characteristic features on MSCT angiography of arterial sequestration. Methods: The MSCT images of 5 patients with arterial sequestration were retrospectively reviewed. All patients underwent MSCT contrast-enhanced angiography. 3D rendering was made to evaluate the lung parenchyma, bronchial system, and vascular anatomy. Results: All 5 cases demonstrated the anomalous systemic artery (ASA) as an isolated and tortuous artery arising from the descending thoracic aorta, taking a sigmoid course and running along with airway, entering the basal segments of the left lowed lobe. The inferior pulmonary vein (IPV) was significantly engorged. The typical AS was diagnosed in 4 patients. Its ASA intercrossed with the IPV and two branches entering segments 7 and 8 over the IPV, and two branches entering segments 9 and 10 under the IPV. The volume of involved lung shrunk with the artery markedly engorged. A characteristic avascular section was found between the pulmonary artery supplying area and the ASA supplying area, and the bronchi did not accompany the arteries. One was diagnosed atypical AS because of coexistence with bronchial atresia. Conclusion: The arterial sequestration had characteristic MSCT findings. The typical type can be definitely diagnosed, but the atypical type needs further three-dimensional analysis. (authors)

Assessment of pulmonary function using pixel indexes of multiple-slice spiral CT low-dose two-phase scanning in chronic obstructive pulmonary disease

International Nuclear Information System (INIS)

Zhang Lihua; Wang Yunhua; Jiang Zhongbiao; Zhang Lejun; Sun Wanli; Zhang Chunming

2012-01-01

Objective: To explore the values of pixel indexes (PI) with multiple-slice spiral CT low-dose two-phase scanning for assessing the pulmonary function in chronic obstructive pulmonary disease (COPD). Methods: Thirty-six patients with COPD (COPD group)and 30 healthy people (control group)underwent pulmonary function test (PFT). Chest 64-MSCT low-dose (50 mAs) scanning at full inspiration and expiration, routine scanning (100 mAs) at inspiration were performed. The effective dose (ED) was calculated. The lung was divided into three regions (upper, middle, lower). PI of lung were divided into five groups: -960--1024, -910--960, -800--910, -700--800, -400--700. The PI -910 (sum of the PI under -910 HU) of low-dose scanning at each region were measured and calculated using pulmo software. All PI included PIin -910 , PIiex -910 , PIin -910 -PIiex -910 , PIiex -910 /PIin -910 and (PIin -910 -PIiex -910 )/PIin -910 . All patients underwent PFT within 3 days after 64-MSCT canning, FEV1% and FEV1/FVC were selected for comparison. Results: The PIin in three regions (-960 - -1024, -910 - -960, -800 - -910) were statistically significant between normal and COPD groups (U=0.00, 57.00, 20.50, P<0.01). The PIex in all regions were statistically significant (U=0.00, 0.00, 71.52, 191.00, 6.00, P<0.01). PI -910--1024 at expiration and inspiration were correlated with FEV1% and FEV1/FVC (r=-0.548, -0.664, -0.752, -0.781, P<0.01). PIin -910 , PIex -910 ,PIiex -910 /PIin -910 , (PIin -910 -PIex -910 )/PIin -910 had a good correlation with FEV1% and FEV1/FVC (r=-0.548, -0.664, -0.752, -0.781, -0.674, -0.642, 0.674, 0.642, P<0.01). Conclusion: Pixel indexes of 64-MSCT low-dose two-phase scanning can be used to evaluate pulmonary function in COPD patients. (authors)

Evaluation of radiation exposure with singleslice- and a multislice-spiral CT system (a phantom study)

International Nuclear Information System (INIS)

Giacomuzzi, S.M.; Rieger, M.; Lottersberger, C.; Peer, S.; Peer, R.; Buchberger, W.; Bale, R.; Mallouhi, A.; Jaschke, W.; Torbica, P.; Perkmann, R.

2001-01-01

The purpose of study was to compare patient dose applying singleslice- and multislice-spiral CT. Methods: The examinations were performed with a singleslice-spiral CT (Highspeed Advantage; GE Medical Systems; Milwaukee, USA) and with a multislice CT systems (LightSpeed QX/i GE Medical Systems; Milwaukee, USA). For the determination of the radiation exposure (absorbed dose) a selection of most executed protocols (thorax-helical, abdomen-helical, petrous bone-axial, head-axial) were simulated using an Alderson Rando Phantom. The dose was determined by means of lithiumfluorid-thermoluminescence dosimeters (TLD-GR 200). Results: For thorax and abdomen protocols higher energy dose values could be found using a multislice CT. On the average the energy dose values were increased by 2.6 on an average in relation to single slice spiral CT. The energy dose values of the multisclice CT using head protocols could be reduced by 30% in relation to single slice spiral CT due to suitable parameter selections. The energy dose applying a petrous bone protocol resulted in an average increase by a factor 1.5 using a multislice CT. Conclusion: Using the new multislice CT technique protocol strategies must be optimized regarding the patient doses. Users can operate critically in the sense of the radiation protection only if they are aware of the occurring dose amounts to the patient. (orig.) [de

Clinical application of the three-dimensional reconstruction of spiral CT pneumocolon

International Nuclear Information System (INIS)

Yu Shenping; Li Ziping; Xu Dasheng; Lin Erjian; Lin Peizhang; Xu Qiaolan

2000-01-01

Objective: To evaluate the clinical role of the 3 types of reconstruction of the spiral CT pneumocolon in the diagnosis of colon lesions. Methods: Three types of reconstruction with spiral CT pneumocolon including air cast imaging (ACI), CT virtual endoscopy (CTVE), and multiple planner reconstruction (MPR) in 34 patients with colorectal cancer or polyps were correlated with surgical pathology respectively. Results: Among the 34 patients, 30 was colorectal cancer and 6 was polyps (2 of which in the proximal lumen of 2 colon cancer). (1) Comparison between the 3 types of the spiral CT pneumocolon reconstruction and pathology in colorectal cancer. 1) ACI: tumor patterns: coincide (n =22), anti-coincide (n = 8); tumor extension: coincide (n = 24), anti-coincide (n = 6); tumor size: coincide (n = 28), anti-coincide (n = 2). 2) CTVE: tumor patterns: coincide (n = 26), anti-coincide (n = 4); tumor extension: coincide (n = 25), anti-coincide ( n 5); tumor size: coincide (n = 23), anti-coincide (n = 7). 3) MPR: tumor patterns: coincide (n = 24), anti-coincide (n = 6); tumor extension: coincide (n = 30), anti-coincide (n = 0); tumor size: coincide (n = 26), anti-coincide (n = 4). (2) Comparison between the 3 types of the spiral CT pneumocolon reconstruction and pathology in colorectal polyps: the lesions were displayed in 4 (ACI) and in 6 (CTVE and MPR). Conclusion: (1) For the diagnosis of colorectal cancers: CTVE was the best means to display the tumor patterns, MPR most correct to judge the tumor extension, and ACI most suitable to measure the tumor size. (2) For the diagnosis of colorectal polyps, ACI can be used for oriented diagnosis, CTVE can well display the intra-luminal three-dimensional structure and can be used for characteristic diagnosis, MPR can be used for differential diagnosis

Synchronized control of spiral CT scan for security inspection device

International Nuclear Information System (INIS)

Wang Jue; Jiang Zenghui; Wang Fuquan

2008-01-01

In security inspection system of spiral CT, the synchronization between removing and rotating, and the scan synchronization between rotating and sampling influence quality of image reconstruction, so it is difficulty and important that how to realize synchronized scan. According to the controlling demand of multi-slice Spiral CT, the method to realize synchronized scan is given. a synchronized control system is designed, in which we use a industrial PC as the control computer, use magnetic grids as position detectors, use alternating current servo motor and roller motor as drivers respectively drive moving axis and rotating axis. This method can solve the problem of synchronized scan, and has a feasibility and value of use. (authors)

Functioning islet cell tumor of the pancreas. Localization with dynamic spiral CT

International Nuclear Information System (INIS)

Chung, M.J.; Choi, B.I.; Han, J.K.; Chung, J.W.; Han, M.C.; Bae, S.H.

1997-01-01

Purpose: The purpose of this study was to evaluate the usefulness of dynamic spiral CT, including multidimensional reformation, in the detection and localization of islet cell tumors of the pancreas. Material and Methods: Seven patients with histopathologically proven functioning islet cell tumors of the pancreas were studied with 2-phase contrast-enhanced spiral CT. Scanning of the arterial phase and late phase was started 30 s and 180 s, respectively, after injection of 100 ml of contrast medium at a rate of 3 ml/s. Results: Axial images in the arterial phase depicted the lesions in 5 patients, but in the late phase in only one patient. Multiplanar reformatted images of the arterial phase depicted the lesions in all 7 patients. Maximal intensity projection images demonstrated all lesions with information of their relationship to the vascular structure. Conclusion: Dynamic spiral CT with scanning during the arterial phase and retrospective multidimensional reformation is useful for preoperative detection and localization of small islet cell tumors of the pancreas. (orig.)

Prevalence of ligamentum arteriosum calcification on multi-section spiral CT and digital radiography.

Science.gov (United States)

Hong, Gil-Sun; Goo, Hyun Woo; Song, Jae-Woo

2012-06-01

To investigate the prevalence of ligamentum arteriosum calcification (LAC) on multi-section spiral CT and digital radiography. Five hundred and eight children and 232 adults who performed multi-section chest CT were included in this study and were divided into nine age groups: A (0-5 years), B (6-10 years), C (11-15 years), D (16-20 years), E (21-30 years), F (31-40 years), G (41-50 years), H (51-60 years), and I (61-70 years). Two radiologists assessed the presence of LAC on axial and coronal CT images, defined as focal calcific density on both or on one plane with attenuation >100 Hounsfield unit. The prevalence of LAC on CT was compared between children and adults, and between unenhanced and enhanced CT in children. The prevalence of LAC on digital radiography was evaluated in 476 children. The prevalence of definite LAC on unenhanced multi-section CT was significantly higher in children (37.8 %) than in adults (11.2 %) (P CT were 4.5, 12.8, 8.1, 19.0, 0.0, 0.0, 0.0, 2.0, and 1.9 %. In children, the prevalence of LAC was significantly higher on unenhanced than on enhanced CT (37.8 vs. 16.4 %, P children. LAC is frequently observed in children and adults on multi-section spiral CT, more frequently than previously reported. Compared with that on multi-section spiral CT, the prevalence of LAC on digital radiography is substantially low.

Value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis

International Nuclear Information System (INIS)

Wang Kang; Zhao Zehua; Wang Zhi; Wang Weizhong; Xu Songsen; Zhang Miao; Liu Wenjin; Zhang Guozhen; Feng Dianxu

2005-01-01

Objective: To investigate the value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis. Methods: A total of 39 patients with clinically suspected acute appendicitis underwent surgery from February, 2002 to September, 2003. They were prospectively examined before surgery with routine CT scanning and MPVR reconstruction spiral CT. 31 cases of appendicitis were confirmed after appendectomy. CT scans and surgery-pathology reports were evaluated on a five-grade scale from hyperemic-edematous appendix to abscess (normal appendix: 0 grade). Results: The results of spiral CT MPVR reconstruction were compared with the surgical and pathologic findings at appendectomy, yielding an accuracy of 87.2%, sensitivity of 90.3%, specificity of 75%, positive predictive value of 93.3%, and negative predictive value of 66.7%, respectively. Results of routine CT yielded an accuracy of 38.5%, sensitivity of 38.7%, specificity of 37.5%, positive predictive value of 70.6%, and negative predictive value of 13.6%, respectively. MPVR reconstruction signs of 28 patients with acute appendicitis included enlarged appendix ( > 6 mm) (96.4%), appendicoliths (26.7%), caecal apical thickening (36.7%), periappendiceal inflammation (71.4%), and abscess (10.7%). Conclusion: The use of spiral CT MPVR reconstruction in patients with equivocal clinical presentation suspected of having acute appendicitis can lead to a significant improvement in the preoperative diagnosis and maybe a decrease in surgical-pathologic severity of appendiceal disease. (authors)

Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

DEFF Research Database (Denmark)

Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

2008-01-01

PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twenty......-seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP (3)He-MRI and MSCT. Mean age was 55 (+/-12) years, 18 female and 9 male. Mean ADC from (3)He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0...

Automatic exposure control to reduce the dose in subsecond multislice spiral CT: phantom measurements and clinical results

International Nuclear Information System (INIS)

Greess, H.; Bautz, W.; Baum, U.; Wolf, H.; Suess, C.; Kalender, W.A.

2004-01-01

Purpose: To investigate the potential of dose reduction in multislice spiral CT (MSCT) with automatic exposure control. Materials and Methods: The study was performed on a Sensation 4 multislice scanner. This prototype implementation analyzed the distribution of the attenuation along the z-axis in the lateral and sagittal directions of the digital radiogram. Depending on this distribution of the attenuation, the tube current (mA) is defined for every tube rotation. In addition, the tube current was modulated during each tube rotation. First, a three step oval water phantom was measured to evaluate the potential of this method with respect to dose reduction and image quality. In a patient study (n=26), four different scan regions (shoulder, thorax, abdomen, pelvis) were examined and dose (mAs) and image quality evaluated in comparison to examinations with a standard protocol for these regions in adults and a weight-adjusted standard protocol in children. The image quality was classified in consensus as good, sufficient and poor image quality. Results: By adapting and modulating the tube current, we substantially reduced the variation of noise in one spiral scan and in one scan region of our patient collective. The dose (average mAs) was reduced by 31% to 66% in children (mean 44%) and between 35% and 64% in adults (mean 53%), depending on the scan region. The image quality was substantially improved in regions with high attenuation and did not suffer in low attenuation regions. Conclusion: The dose can be reduced substantially by an automatic exposure control including angular tube current modulation with the same or improved image quality. (orig.) [de

Hyaline cartilage thickness in radiographically normal cadaveric hips: comparison of spiral CT arthrographic and macroscopic measurements.

Science.gov (United States)

Wyler, Annabelle; Bousson, Valérie; Bergot, Catherine; Polivka, Marc; Leveque, Eric; Vicaut, Eric; Laredo, Jean-Denis

2007-02-01

To assess spiral multidetector computed tomographic (CT) arthrography for the depiction of cartilage thickness in hips without cartilage loss, with evaluation of anatomic slices as the reference standard. Permission to perform imaging studies in cadaveric specimens of individuals who had willed their bodies to science was obtained from the institutional review board. Two independent observers measured the femoral and acetabular hyaline cartilage thickness of 12 radiographically normal cadaveric hips (from six women and five men; age range at death, 52-98 years; mean, 76.5 years) on spiral multidetector CT arthrographic reformations and on coronal anatomic slices. Regions of cartilage loss at gross or histologic examination were excluded. CT arthrographic and anatomic measurements in the coronal plane were compared by using Bland-Altman representation and a paired t test. Differences between mean cartilage thicknesses at the points of measurement were tested by means of analysis of variance. Interobserver and intraobserver reproducibilities were determined. At CT arthrography, mean cartilage thickness ranged from 0.32 to 2.53 mm on the femoral head and from 0.95 to 3.13 mm on the acetabulum. Observers underestimated cartilage thickness in the coronal plane by 0.30 mm +/- 0.52 (mean +/- standard error) at CT arthrography (P cartilage thicknesses at the different measurement points was significant for coronal spiral multidetector CT arthrography and anatomic measurement of the femoral head and acetabulum and for sagittal and transverse CT arthrography of the femoral head (P cartilage thickness from the periphery to the center of the joint ("gradients") were found by means of spiral multidetector CT arthrography and anatomic measurement. Spiral multidetector CT arthrography depicts cartilage thickness gradients in radiographically normal cadaveric hips. (c) RSNA, 2007.

Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography

International Nuclear Information System (INIS)

Young, N.; Kingston, R.J.; Markson, G.; Dorsch, N.W.C.; McMahon, J.

2001-01-01

The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97%, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74%) with clips. The specificity of CTA was 86% with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms. (orig.)

Whole-body CT. Spiral and multislice CT. 2. tot. rev. and enl. ed.

International Nuclear Information System (INIS)

Prokop, M.; Galanski, M.; Schaefer-Prokop, C.; Molen, A.J. van der

2007-01-01

Spiral and multidetector techniques have improved the diagnostic possibilities of CT, so that image analysis and interpretation have become increasingly complex. This book represents the current state of the art in CT imaging, including the most recent technical scanner developments. The second edition comprises the current state of knowledge in cT imaging. There are new chapters on image processing, application of contrasting agents and radiation dose. All organ-specific pathological findings are discussed in full. There are hints for optimum use and interpretation of CT, including CT angiography, CT colonography, CT-IVPL, and 3D imaging. There is an introduction to cardio-CT, from calcium scoring and CTA of the coronary arteries to judgement of cardiac morphology. There are detailed scan protocols with descriptions of how to go about parameter selection. Practical hints are given for better image quality and lower radiation exposure of patients, guidelines for patient preparation and complication management, and more than 1900 images in optimum RRR quality. (orig.)

Efficacy of spiral CT in the evaluation of peritoneal seeding of gastric cancer

International Nuclear Information System (INIS)

Choi, Hyuck Jae; Han, Joon Koo; Kim, Tae Kyoung; Kim, Ah Young; Lee, Joon Woo; Moon, Min Hoan; Yang, Han Kwang; Choi, Byung Ihn

2001-01-01

To determine usefulness of spiral CT in the preoperative evaluation of peritoneal seeding from a gastric carcinoma. From a database of 411 consecutive patients with surgically proven advanced gastric cancinoma obtained over a six-month period, 17 with peritoneal seeding and a control group of 24 without peritoneal seeding underwent spiral CT scanning with 7-8 mm scan thickness and interval during the portal phase. Preoperative CT images were analyzed by two readers who reached a consensus with regard to the presence and location of the ascites, thickening of the parietal peritoneum, and changes in the omentum and mesentery. Ascites was present in 47% (8/17) of patients with peritoneal seeding the right subhepatic space (n=6, 35%) and right paracolic gutter (n=5, 29%)-but not the cul-de-sac (n=2, 12%)-were common sites of fluid collection. Permeative changes in the omentum and mesentery were seen in 18% (3/17) and 12% (2/17) of patients, respectively. Among five controls with false positive results, ascites in the cul-de-sac was present in three (two males and one female, 12%) while omental nodules and a thickened peritoneum were found in two (8%) and one (4%), respectively. In nine controls with false negative results, small disseminated nodules were seen in the mesentery and omentum at surgical field. The sensitivity and specificity of spiral CT were 47% (8/17) and 79% (19/24), respectively. In terms of sensitivity and specificity, spiral CT is not especially accurate in distinguishing peritoneal seeding from gastric carcinoma

Measurement error of spiral CT volumetry: influence of low dose CT technique

International Nuclear Information System (INIS)

Chung, Myung Jin; Cho, Jae Min; Lee, Tae Gyu; Cho, Sung Bum; Kim, Seog Joon; Baik, Sang Hyun

2004-01-01

To examine the possible measurement errors of lung nodule volumetry at the various scan parameters by using a small nodule phantom. We obtained images of a nodule phantom using a spiral CT scanner. The nodule phantom was made of paraffin and urethane and its real volume was known. For the CT scanning experiments, we used three different values for both the pitch of the table feed, i.e. 1:1, 1:15 and 1:2, and the tube current, i.e. 40 mA, 80 mA and 120 mA. All of the images acquired through CT scanning were reconstructed three dimensionally and measured with volumetry software. We tested the correlation between the true volume and the measured volume for each set of parameters using linear regression analysis. For the pitches of table feed of 1:1, 1:1.5 and 1:2, the mean relative errors were 23.3%, 22.8% and 22.6%, respectively. There were perfect correlations among the three sets of measurements (Pearson's coefficient = 1.000, p< 0.001). For the tube currents of 40 mA, 80 mA and 120 mA, the mean relative errors were 22.6%, 22.6% and 22.9%, respectively. There were perfect correlations among them (Pearson's coefficient=1.000, p<0.001). In the measurement of the volume of the lung nodule using spiral CT, the measurement error was not increased in spite of the tube current being decreased or the pitch of table feed being increased

The experimental study and clinical application on the detection of pulmonary nodules with low-dose multislice spiral CT

International Nuclear Information System (INIS)

Wu Xiaohua; Ma Daqing; Zhang Zhongjia; Ji Jingling; Zhang Yansong

2004-01-01

Objective: To investigate the detection rate of pulmonary nodules ,especially nodules ≤5 mm, in variable low-doses, and to evaluate the imaging quality of low-dose MSCT. Methods: Six postmortem specimens of patients with pneumoconiosis after necropsy were fixed at end-inspiratory volume. The fixed specimens were examined by using MSCT with standard dose (130 mA) and low-dose (50, 30, 10 mA, respectively). Low-dose MSCT scans of 40 asymptomatic volunteers and 60 patients with pulmonary metastasis were also examined with 30 mA. The numbers of pulmonary nodules less than 5 mm at standard-dose and different low-dose were recorded. Nodules were assessed by diagnostic confidence ('definite nodule', 'questionable nodule', and 'definite not nodule'). The number of images with artifact in specimens and in 40 volunteers and 60 patients with pulmonary metastasis were recorded. Results: In specimen's study, the Kappa values of groups of low-dose (50, 30, 10 mA) were 0.515, 0.242, and 0.154, respectively. The group of 50 mA had a good coincidence with standard-dose group by U test. The sensitivity of group 50, 30, 10 mA was 88.0%, 78.4%, and 75.0%, respectively. The positive predictive values of which were 98%, 94%, and 93%, respectively. The correction rates of which were 85%, 73%, and 69%, respectively. In specimens' images, subtle linear artifact was showed only in paravertebral lung field in 21 images of 31 at the group of 10 mA. Linear artifacts that affected small nodule detection were showed in lung apexes in 3 of 100 subjects. Conclusion: Low-dose MSCT is expected to improve early detection of lung cancer. Pulmonary nodules less than 5 mm could be reliably detected at 50 mA tube current in specimens. Low-dose CT (30 mA) showed satisfactory imaging quality in our study. Low-dose CT screening for lung cancer may be applied if situation permits. (authors)

Thin-section CT vs spiral CT in candidates for lung volume reduction surgery: a comparison based on radiologists' subjective preferences

International Nuclear Information System (INIS)

Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B.; Bergstrand, L.

2001-01-01

The aim of this study was to investigate whether high-resolution (HRCT) or spiral CT was preferred in evaluating severe emphysema in patients undergoing lung volume reduction surgery (LVRS), whether there is any difference in this regard between the cranial and caudal part of the lung, and whether the degree of emphysema has an impact on the radiologists' preference. The study was performed by letting four radiologists compare images obtained with the two techniques (film pairs) and decide which technique they preferred or if the techniques were considered as equal in evaluating emphysema. In evaluation of 188 film pairs, the HRCT images were preferred in 56 %, spiral CT in 19 % and the techniques considered as equal in 25 %. Spiral CT images were preferred more often in the caudal part of the lung and in more advanced emphysema compared with the HRCT images. The study confirms our clinical assumption that use of both CT techniques are valuable in evaluating advanced emphysema and there may be technical as well as histopathological reasons for this. (orig.)

Malignant focal hepatic lesions complicating underlying liver disease: dual-phase contrast-enhanced spiral CT sensitivity and specificity in orthotopic liver transplant patients

International Nuclear Information System (INIS)

Mortele, K.J.; De Keukeleire, K.; Praet, M.; Van Vlierberghe, H.; Hemptinne, B. de; Ros, P.R.

2001-01-01

The aim of this study was to determine the accuracy of contrast-enhanced biphasic spiral CT as a screening tool in the preoperative evaluation of orthotopic liver transplant (OLT) patients. Spiral-CT examinations were performed before liver transplantation in 53 patients. Scans were retrospectively reviewed and compared with pathologic findings in fresh-sectioned livers. When findings between spiral CT and pathology were discordant, formalized livers were reexamined with lesion-by lesion evaluation. Fresh pathologic evaluation revealed 23 liver lesions (16 HCC, 7 macro-regenerative nodules). Malignancy was identified in 13 of 53 patients (24.5%). Pre-transplantation spiral CT depicted 27 liver lesions (23 HCC, 4 macro-regenerative nodules). Malignancy was suspected in 14 patients (26.4%). In 10 of 53 (18.9%), spiral CT and pathologic evaluation were discordant. Subsequent retrospective pathologic evaluation showed malignancy in 4 additional patients. Spiral CT compared with the retrospective pathologic findings revealed 36 real-negative, 14 real-positive, 0 false-positive, and 3 false-negative patients with malignancy. Sensitivity and specificity of spiral CT in detection of malignancy was 82 and 100%, respectively. Contrast-enhanced biphasic spiral CT is an accurate technique in the evaluation of patients preceding OLT. Routine fresh-sectioned liver pathologic findings are not as sensitive as previously estimated. (orig.)

The potentials of spiral CT for detection of focal liver lesions

International Nuclear Information System (INIS)

Helmberger, H.; Kersting-Sommerhoff, B.; Lenz, M.; Kirsten, R.; Bautz, W.

1996-01-01

Spiral CT currently is the modality of choice for all aspects of diagnostic evaluation of the liver. Optimal selection of treatment should be based inter alia on the findings obtained by spiral CT with arterial application of contrast medium, as for example S-CTA (primary liver tumors), or S-CTAP (secondary liver tumors). Ultrasonography is the major supplementing modality. In the near future, MR imaging applying liver-specific contrast-enhancing agents is expected to become an important competing technique, and further developments of interest in diagnostic imaging of the liver are in the offing: it is not yet known which technique will be the modality of choice at the onset of the 21st century. (orig.) [de

Pulmonary sequestration: diagnosis with three dimensional reconstruction using spiral CT

International Nuclear Information System (INIS)

Nie Yongkang; Zhao Shaohong; Cai Zulong; Yang Li; Zhao Hong; Zhang Ailian; Huang Hui

2003-01-01

Objective: To evaluate the role of three dimensional (3D) reconstruction using spiral CT in the diagnosis of pulmonary sequestration. Methods: Ten patients with pulmonary sequestration were analyzed. The diagnoses were confirmed by angiography in 2 patients, by operation in 2 patients, and by CT angiography in 6 patients. All patients were examined with Philips SR 7000 or GE Lightspeed Plus scanner. CT images were transferred to a workstation and 3D reconstruction was performed. All images were reviewed and analyzed by two radiologists. Results: Among 10 patients, the pulmonary sequestration was in the right lower lobe in 1 patient and in the left lower lobe in 9 patients. Anomalous systemic arteries originated from thoracic aorta in 8 patients and from celiac artery in 2 patients. On plain CT scan, there were 4 patients with patchy opacities, 3 patients with hilar mass accompanying vascular engorgement and profusion in adjacent parenchyma, 2 patients with finger-like appendage surrounded by hyper-inflated lung, and 1 patient with lung mass-like lesion. Enhanced CT revealed anomalous systemic arteries in 9 patients and drainage vein in 7 patients. Maximum intensity projection (MIP) and curvilinear reconstruction could depict the abnormal systemic artery and drainage vein in sequestration. Surface shadow display (SSD) and volume rendering (VR) could delineate the anomalous systemic artery. Conclusion: 3D reconstruction with enhanced spiral CT can depict anomalous systemic artery and drainage vein and it is the first method of choice in diagnosing pulmonary sequestration

Fuzzy-neural network in the automatic detection and volumetry of the spleen on spiral CT scans

International Nuclear Information System (INIS)

Heitmann, K.R.; Mainz Univ.; Rueckert, S.; Heussel, C.P.; Thelen, M.; Kauczor, H.U.; Uthmann, T.

2000-01-01

Purpose: To assess spleen segmentation and volumetry in spiral CT scans with and without pathological changes of splenic tissue. Methods: The image analysis software HYBRIKON is based on region growing, self-organized neural nets, and fuzzy-anatomic rules. The neural nets were trained with spiral CT data from 10 patients, not used in the following evaluation on spiral CT scans from 19 patients. An experienced radiologist verified the results. The true positive and false positive areas were compared in terms to the areas marked by the radiologist. The results were compared with a standard thresholding method. Results: The neural nets achieved a higher accuracy than the thresholding method. Correlation coefficient of the fuzzy-neural nets: 0.99 (thresholding: 0.63). Mean true positive rate: 90% (thresholding: 75%), mean false positive rate: 5% (thresholding>100%). Pitfalls were caused by accessory spleens, extreme changes in the morphology (tumors, metastases, cysts), and parasplenic masses. Conclusions: Self-organizing neural nets combined with fuzzy rules are ready for use in the automatic detection and volumetry of the spleen in spiral CT scans. (orig.) [de

Comparison of spiral CT angiography with conventional digital subtraction angiography in the evaluation of renal transplant donors: a pilot study

International Nuclear Information System (INIS)

Chu, C.; Young, N.; Lau, H.

2001-01-01

Conventional digital subtraction renal arteriography (IA-DSA) has been traditionally used as the preoperative imaging modality for assessment of renal vascular anatomy for renal transplant donors. This study evaluates the potential use of spiral CT angiography in replacing IA-DSA in the preoperative assessment of this group of patients. Seven patients underwent both spiral CT angiography and IA-DSA between October 1997 and April 1998. It is concluded that spiral CT angiography can demonstrate the number, length and location of renal arteries and it is suggested that spiral CT angiography can potentially replace IA-DSA in the preoperative assessment of renal donors. Copyright (2001) Blackwell Science Pty Ltd

Pitfalls in the use of spiral CT for identification of intracranial aneurysms

International Nuclear Information System (INIS)

Young, N.; Kingston, R.J.; Dorsch, N.W.C.

1999-01-01

We describe problems encountered in our first 136 patients, with 95 aneurysms, who underwent spiral CT for investigation of possible aneurysms involving the circle of Willis and adjacent major vessels, and who had surgical and/or angiographic confirmation. There were seven false-positive cases, of which the first three could be explained by operator inexperience. There were four false negatives, all small aneurysms; two were not seen because of operator error and two were hidden by an adjacent larger aneurysm. Clip artefacts prevented diagnostic studies in six of 21 postoperative studies. One aneurysm was outside the CT field of view, being on a pericallosal artery. One basilar artery tip aneurysm was excluded from the field of the CT study because of a planning error. Inspection of the axial source images is critical if the diagnosis of small or thrombosed aneurysms is to be made. Close attention to image acquisition and computer modelling is required to reduce errors in spiral CT angiography of intracranial aneurysms. (orig.)

The findings and the role of axial CT imaging and 3D imaging of gastric lesion by spiral CT

International Nuclear Information System (INIS)

Lee, Dong Ho; Ko, Young Tae

1996-01-01

The purpose of this study is to assess the efficacy of axial CT imaging and 3D imaging by spiral CT in the detection and evaluation of gastric lesion. Seventy-seven patients with pathologically-proven gastric lesions underwent axial CT and 3D imaging by spiral CT. There were 49 cases of advanced gastric carcinoma(AGC), 21 of early gastric carcinoma (EGC), three of benign ulcers, three of leiomyomas, and one case of lymphoma. Spiral CT was performed with 3-mm collimation, 4.5mm/sec table feed, and 1-1.5-mm reconstruction interval after the ingestion of gas. 3D imaging was obtained using the SSD technique, and on analysis a grade was given(excellent, good, poor). Axial CT scan was performed with 5-mm collimation, 7mm/sec table feed, and 5-mm reconstruction interval after the ingestion of water. Among 49 cases of AGC, excellent 3D images were obtained in seven patients (14.3%), good 3D images in 30(61.2%), and poor 3D images in 12(24.5%). Among the 12 patients with poor images, the cancers were located at the pyloric antrum in eight cases, were AGC Borrmann type 4 in three cases, and EGC-mimicking lesion in one case. Using axial CT scan alone, Borrmann's classification based tumor morphology were accurately identified in 67.3% of cases, but using 3D imaging, the corresponding figure was 85.7%. In 33 cases receiving surgery, good correlation between axial CT scan and pathology occurred in 72.7% of T class, and 69.7% of N class. Among 21 cases of EGC, excellent 3D images were obtained in three patients (14.3%), good 3D images in 14 (66.7%), and poor 3D images in two (9.5%). The other two cases of EGC were not detected. By axial CT scan, no tumor was detected in four cases, and there were two doubtful cases. 3D images of three benign ulcers were excellent in one case and good in two. 3D images of three leiomyomas and one lymphoma were excellent. Combined axial CT imaging and 3D imaging by spiral CT has the potential to accurately diagnose gastric lesions other than AGC

Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

International Nuclear Information System (INIS)

Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo; Kim, Ah Young; Lee, Hyun Ju; Song, Chi Sung; Choi, Byung Ihn

2000-01-01

To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

Thin-section CT vs spiral CT in candidates for lung volume reduction surgery: a comparison based on radiologists' subjective preferences

Energy Technology Data Exchange (ETDEWEB)

Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B. [Dept. of Thoracic Radiology, Karolinska Hospital, Stockholm (Sweden); Bergstrand, L. [Dept. of Radiology, Danderyds Hospital (Sweden)

2001-03-01

The aim of this study was to investigate whether high-resolution (HRCT) or spiral CT was preferred in evaluating severe emphysema in patients undergoing lung volume reduction surgery (LVRS), whether there is any difference in this regard between the cranial and caudal part of the lung, and whether the degree of emphysema has an impact on the radiologists' preference. The study was performed by letting four radiologists compare images obtained with the two techniques (film pairs) and decide which technique they preferred or if the techniques were considered as equal in evaluating emphysema. In evaluation of 188 film pairs, the HRCT images were preferred in 56 %, spiral CT in 19 % and the techniques considered as equal in 25 %. Spiral CT images were preferred more often in the caudal part of the lung and in more advanced emphysema compared with the HRCT images. The study confirms our clinical assumption that use of both CT techniques are valuable in evaluating advanced emphysema and there may be technical as well as histopathological reasons for this. (orig.)

The application and value of 64 multislice spiral CT of left atrium and pulmonary vein in radio-frequency ablation of atrial fibrillation

International Nuclear Information System (INIS)

Guo Xi; Lv Biao; Zhang Zhaoqi; Zhao Yike; Jiang Hong; Ma Changsheng; Yu Ronghui; Wang Xue; Cao Hainian

2008-01-01

Objective: Analyzing the left atrium and pulmonary vein morphologically by 64 multislice spiral CT (MSCT) scan to guide the catheter ablation of Atrial fibrillation. Methods: Two hundred and thirty-two patients (146 cases in atrial fibrillation group and 86 cases in control group) received 64 MSCT examination of the left atrium and pulmonary vein. The incidence of anatomical variation of pulmonary vein was compared between atrial fibrillation group and control group. For each group, the anatomical morphology of every pulmonary vein and the auricle of left atrium was analyzed, the diameter of the orifice of each pulmonary vein and the size of left atrium were measured. Results: Sixty-four MSCT of left atrium and pulmonary vein could demonstrate detailed connecting type between left atrium and pulmonary veins and the possible anatomical variation. Anatomical variation of pulmonary vein in this study accounted for 16.8% (39/232) of total sample. For both groups, orifices of pulmonary veins appeared oval and their superoinferior diameters were larger than their anteroposterior diameters. There was significant difference in the inner diameter of left atrium between atrial fibrillation group and control group [atrial fibrillation group: (39.47 ± 8.98) mm, control group: (36.94±5.49) mm, P=0.02], while there was no difference in the diameters of orifices of pulmonary veins between two groups [superoinferior diameters of pulmonary veins in atrial fibrillation group: left-up (18.15±1.35) mm, left-down (16.96±1.18) mm, right-up (17.50±1.12) mm, fight-down (17.65±0.94) mm, superoinferior diameters of pulmonary veins in control group: left-up (18.07±0.94) mm, left-down (17.50±0.57) mm, right-up (18.03±1.02) mm, fight-down (17.94±0.76) mm, the corresponding P>0.05, respectively, anteroposterior diameters of pulmonary veins in atrial fibrillation group: left-up (12.26±1.89) mm, left-down (11.96±0.61) mm, right-up (12.32± 1.08) mm, fight-down (12.39±0.95) mm

Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction

International Nuclear Information System (INIS)

Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stephane; Maldague, Baudouin

2003-01-01

Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries. (orig.)

Value of cardiac multislice spiral CT for the assessment of degenerative aortic stenosis: comparison with echocardiography

International Nuclear Information System (INIS)

Mahnken, A.H.; Wildberger, J.E.; Das, M.; Muehlenbruch, G.; Guenther, R.W.; Koos, R.; Sinha, A.M.; Stanzel, S.

2004-01-01

Objective: To non-invasively assess the severity of aortic valve stenosis (AS) by the determination of aortic valve calcification (AVC) using multislice spiral computed tomography (MSCT). Materials and Methods: Forty-one consecutive patients (17 male, 24 female, mean age 71.0±7.9 years) with a history of AS and an aortic valve area ≤2 cm 2 underwent retrospectively ECG-gated 4-slice MSCT and echocardiography. The AVCs were quantitatively assessed using the score described by Agatston as well as by calculating the calcium mass. The echocardiographically determined aortic valve area (AVA) and the severity of AS according to the ACC/AHA guidelines were compared to the degree of a aortic valve calcifications. Pearson's correlation coefficient, cut-off values, kappa test and F-test with post hoc Boneferroni t-tests were calculated. Results: Calcium scores were significantly higher in patients with severe AS, when compared to mild or moderate AS (p<0.001). In patients suffering from severe AS, the mean Agatston score was 4125.5±1168.9 (calcium mass 904.1±263.3) while in patients with moderate and mild AS the corresponding values were 1596.3±987.0 (319.1±208.3) and 785.9±390.1 (149.1±90.2), respectively. Pearson's correlation coefficients were r-=0.75 for the Agatston score and r=-0.72 for the calcium mass. There was a moderate agreement between severity of AS according to the ACC/AHA guidelines and the degree of AS determined from AVC scores with κ=0.6091 and κ=0.6985, respectively. Conclusion: Severe AS may be differentiated from moderate or mild AS using cardiac MSCT. Extensive calcifications of the aortic valve presenting with an Agatston-Score ≥2824 (calcium mass ≥611) indicate a severe AS and should be taken as an indication for further diagnostic workup. (orig.)

Evaluation of spiral CT in staging of colon and rectum carcinoma

International Nuclear Information System (INIS)

Hundt, W.; Braunschweig, R.; Reiser, M.

1999-01-01

The purpose of our study was to evaluate the capability of a subsecond spiral-CT scanner using two contrast medium phases in staging of colorectal cancer. In our study we included 37 patients with proven rectum or colon carcinoma. Spiral CT was performed following tap-water enema of the colon in the arterial and venous phases of contrast medium enhancement. Our results were compared with the findings of pathological examination after surgery. The tumor's size and extension were evaluated in the arterial and venous phases, the lymph nodes in the venous phase of the CT scan. The tumor was in the rectum (n = 14), sigma (n = 11), descending colon (n = 6), and cecum (n = 6). Two-phase spiral CT had a sensitivity of 97.2 % in the arterial phase and 89.1 % in the venous phase in detecting the carcinoma. The staging results were in the arterial phase in 30 of 37 cases (81.0 %) and in the venous phase in 24 of 37 cases (64.8 %) according to pathology. In 27 of 32 patients (84.3 %) lymph nodes were detected. The correct classification of the N-stage was possible in 23 of 34 cases (67.6 %). The combined use of arterial and venous phases in staging of colorectal cancer can improve the T- and N-stage classification in comparison with using only one contrast medium phase. The arterial phase is superior compared with the venous phase for local tumor staging and the venous phase is used for lymph node assessment. (orig.) (orig.)

Hepatic hemangioma: contrast enhancement patterns on two-phase spiral CT

International Nuclear Information System (INIS)

Yun, Eun Joo; Choi, Byung Ihn; Han, Joon Koo; Jang, Hyun Jung; Kim, Tae Kyoung; Kim, Ah Young; Lee, Ki Yeol

1998-01-01

To evaluate contrast enhancement patterns of hemangioma according to size, as seen during the arterial and portal venous phase of spiral CT. Overall, the most common enhancement pattern was peripheral high (44/82, 53.7%), during the arterial and portal venous phase. The second and third most common patterns were uniform high (11/82, 13.4%) and peripheral high-uniform high (9/82, 11.0%), also during the arterial and portal venous phase. In tumors smaller than 20 mm, low-low attenuation was seen in eight (9.8%), and iso-low attenuation in two (2.4%), during the arterial and portal venous phase, respectively. On two-phase spiral CT, the most common enhancement pattern of hemangioma was peripheral high, seen during the arterial and portal venous phase. However, a small hemangioma less than 2cm may show atypical patterns, including low and iso attenuation. (author). 23 refs., 1 tab., 4 figs

Optimising imaging parameters in experimental spiral CT

International Nuclear Information System (INIS)

Tiitola, M.; Vehmas, T.; Kivisaari, R.P.; Kivisaari, L.

1997-01-01

Purpose: This in vitro study was conducted to analyse lesion detection and relative radiation exposure in different CT techniques. Material and Methods: We used a plastic phantom (12 x 8 x 2 cm) containing holes filled with air or fluid of varying densities to simulate lesions. This was imaged with Siemens Somatom Plus S and GE High Speed Advantage units. We varied table feeds (3 and 6 mm/s in Siemens and 3 and 4.5 mm/s in GE) and increments (2 mm and 4 mm) while keeping collimation at 3 mm. The SmartScan program of GE and the reformating algorithm of Siemens were also analysed. To evaluate the different methods, the phatnom lesions were counted by 3 observers. Radiation exposures associated with each technique were also measured. Results: The images reformatted to a coronal direction were significantly inferior (p<0.01) to those in other techniques. The use of SmartScan did not influence lesion detection, nor did changes in pitch or increment. Spiral and non-spiral techniques proved to be equal. Radiation exposure was lowest when a greater pitch or the SmartScan program was used. Conclusion: Radiation exposure in CT can be limited without significantly impairing the image quality by using low-dose techniques. Reformatting to a coronal direction should be used with care as it debases the image quality. (orig.)

Advanced single-slice rebinning for tilted spiral cone-beam CT

International Nuclear Information System (INIS)

Kachelriess, Marc; Fuchs, Theo; Schaller, Stefan; Kalender, Willi A.

2001-01-01

Future medical CT scanners and today's micro CT scanners demand cone-beam reconstruction algorithms that are capable of reconstructing data acquired from a tilted spiral trajectory where the vector of rotation is not necessarily parallel to the vector of table increment. For the medical CT scanner this case of nonparallel object motion is met for nonzero gantry tilt: the table moves into a direction that is not perpendicular to the plane of rotation. Since this is not a special application of medical CT but rather a daily routine in head exams, there is a strong need for corresponding reconstruction algorithms. In contrast to medical CT, where the special case of nonperpendicular motion is used on purpose, micro CT scanners cannot avoid aberrations of the rotational axis and the table increment vector due to alignment problems. Especially for those micro CT scanners that have the lifting stage mounted on the rotation table (in contrast to setups where the lifting stage holds the rotation table), this kind of misalignment is equivalent to a gantry tilt. We therefore generalize the advanced single-slice rebinning algorithm (ASSR), which is considered a very promising approach for medical cone-beam reconstruction due to its high image quality and its high reconstruction speed [Med. Phys. 27, 754-772 (2000)], to the case of tilted gantries. We evaluate this extended ASSR approach (which we will denote as ASSR + , for convenience) in comparison to the original ASSR algorithm using simulated phantom data for reconstruction. For the case of nonparallel object motion ASSR + shows significant improvements over ASSR, however, its computational complexity is slightly increased due to the broken symmetry of the spiral trajectory

Spiral CT features and anatomic basis of posterior pararenal space involvement in acute pancreatitis

International Nuclear Information System (INIS)

Min Pengqiu; Yan Zhihan; Yang Hengxuan; Liu Zaiyi; Song Bin; Wu Bing; Zhang Jin; Liu Rongbo

2005-01-01

Objective: To evaluate spiral CT features and anatomic basis of the posterior pararenal space (PPS) involvement in acute pancreatitis (AP). Methods: CT images of 87 cases with AP were retrospectively studied with focus on spiral CT features, incidence of the PPS involvement, and its correlations with the posterior renal fascia or lateroconal fascia. Results: Our study showed that the incidence of the PPS involvement was 47% (41/87), with Grade A 53% (46/87), Grade B 24%(21/87), and Grade C 23% (20/87), and Grade 0 53% (46/87), Grade I 22% (19/87), and Grade II 25% (22/87), respectively. The pancreatitis fluid collection in the PPS was continuous with that in the anterior pararenal space or with the fluid between the two laminae of the posterior renal fascia. In 3 follow-up cases, pseudocysts in the PPS were continuous with that in anterior pararenal space below the cone of renal fascia. Conclusion: Spiral CT features of the PPS involvement varies from mild inflammatory changes to fluid collection or phlegmonous mass. Fluid within anterior pararenal space in AP flows into the PPS by three routes. (authors)

The experimental study on bowel ischemia in closed loop obstruction by using multi-phase spiral CT

International Nuclear Information System (INIS)

Zhang Xiaoming; Yang Hanfeng; Huang Xiaohua; Tang Xianying; Jian Pu; Yang Zhengwei; Zhou Jiyong; Zhao Zongwen

2005-01-01

Objective: To evaluate the bowel ischemia in experimental closed loop obstruction by using multi-phase spiral CT. Methods: Twenty-four New Zealand rabbits of both sexes (mean age, 4 months, and mean body weight, 2.5-3.0 kg) were divided randomly into three groups with each group containing 8 rabbits. After clamping 10-15 cm segments of small bowel and their veins for 0.5 hours (Group A), 1-2 hours (Group B), and 3-5 hours (Group C), respectively, multi-phase spiral CT was performed at baseline, and at arterial, venous, and delayed phases after intravenous contrast administration. Then the rabbits were sacrificed to observe their surgical and histological changes. Two radiologists, blinded to the animal model classification and their histological results, individually reviewed the CT images to observe the CT appearances of the closed loop. Statistical significance criteria was determined by P 0.05) at baseline, however, they were significantly different (P<0.05) at all phases after enhancement. Among rabbits without necrotic closed loop, 11 of 13 had continuous enhancement at all phases, while only 1 of 11 rabbits with necrotic closed loop showed continuous enhancement (P<0.05). Conclusion: The ischemia of bowel wall in different phases after clamping small bowel and their veins can be evaluated by using enhanced multi-phase spiral CT. Continuous enhancement of bowel wall in multi-phase spiral CT can be seen prominently in the early bowel ischemia, but necrotic bowel shows no enhancement. (authors)

Spiral-CT-angiography of acute pulmonary embolism: factors that influence the implementation into standard diagnostic algorithms

International Nuclear Information System (INIS)

Bankier, A.; Herold, C.J.; Fleischmann, D.; Janata-Schwatczek, K.

1998-01-01

Purpose: Debate about the potential implementation of Spiral-CT in diagnostic algorithms of pulmonary embolism are often focussed on sensitivity and specificity in the context of comparative methodologic studies. We intend to investigate whether additional factors might influence this debate. Results: The factors availability, acceptance, patient-outcome, and cost-effectiveness-studies do have substantial influence on the implementation of Spiral-CT in the diagnostic algorithms of pulmonary embolism. Incorporation of these factors into the discussion might lead to more flexible and more patient-oriented algorithms for the diagnosis of pulmonary embolism. Conclusion: Availability of equipment, acceptance among clinicians, patient-out-come, and cost-effectiveness evaluations should be implemented into the debate about potential implementation of Spiral-CT in routine diagnostic imaging algorithms of pulmonary embolism. (orig./AJ) [de

Virtual endoscopy using spiral CT in patients with carcinomas of the hypopharynx and larynx

International Nuclear Information System (INIS)

Song, Sang Gook; Seo, Jeong Jin; Chung, Tae Woong; Kim, Hyeong Kil; Jeong, Gwang Woo; Jeong, Yong Yeon; Kang, Heoung Keun; Cho, Jae Sik

2000-01-01

To compare the usefulness of virtual endoscopy using spiral CT with that of laryngoscopy in the detection and evaluation of laryngeal and pharyngeal carcinomas. Twenty-four patients with pathologically proven laryngeal and pharyngeal carcinomas underwent laryngoscopy and virtual endoscopy using spiral CT. Eleven of the carcinomas were supraglottic, five were glottic, and eight were hypopharyngeal. Source images obtained by spiral CT were transmitted to an independent workstation and virtual endoscopic images were obtained using Navigator software. These were graded according to their quality (good, fair, bad), and were interpreted by two radiologists who were blinded to the conventional endoscopic findings. These latter were subsequently compared with the virtual endoscopic findings in terms of similarity to laryngoscopic examination and detectability of lesions. The overall image quality of virtual endoscopy was good in 16 cases (67%), fair in eight (33%), and bad in no case. Among the 11 supraglottic carcinomas, image quality was good in seven cases (64%), and fair in four (36%). In four of the five glottic carcinomas (80%) quality was good, and in one case (20%) it was fair, while among the eight hypopharyngeal carcinomas, quality was good in five cases (63%), and fair in three (37%). Overall, detection of the lesion was possible in 23 cases (96%). Due to the small size of the lesion, the one case of glottic carcinoma was not detected. Virtual endoscopy using spiral CT is a safe and noninvasive method, and also successfully detects laryngeal and pharyngeal lesions, with good image quality. For the evaluation of laryngeal and hypopharyngeal carcinoma, its use ma complement that of axial CT. (author)

Shallow and deep breath lung tumor volume as estimated by spiral volumetric CT in comparison to standard axial CT using virtual simulation

International Nuclear Information System (INIS)

Quader, M.A.; Kalend, A.M.; Deutsch, M.; Greenberger, J.S.

1995-01-01

Purpose/Objective: In order to assess an individual patient tumor volume (TV) margins that are sufficient to design a beam-eye-view (BEW) conformal portal, the radiographic extent of gross tumor volume (GTV) dimensions and its fluctuation with breathing are measured by fast spiral CT scanning of patients treated for Stage II, III lung cancers using 5-6 field multi-collimated conformal beams. Materials and Methods: Over the course of conformal radiotherapy for lung cancer, a full thorax CT scans of the patient were taken by conventional axial CT scanning with patients immobilized in the treatment position and breathing normally. Patient(s) with good pulmonary function test (PFT) status were selected to perform deep breathing and re-scanned by fast spiral techniques in order to re-acquire the tomographic variation in the (GTV) with breathing. A Picker spiral ZAP-100 software running on the AQSim-PQ-2000 was used with a variable helical pitch of 1.0, 1.5 and 2.0. The variable pitch spirals were limited to tumor bed, diaphragm and lung apex area for measurements. Effect of breathing motion along x,y,z direction were then assessed for each beam-eye-view portal as seen in digitally reconstructed radiography (DRR) at the treated gantry angle. Results: Comparison of axial and spiral scans shows the progression of lung and diaphram motion with breathing can be gauged better in spiral scans. The movement of the diaphragm during shallow breathing has been found to be 2-3cm by measuring the distance between the most inferior and superior slices where diaphragm is present. The variation of the tumor dimensions along AP/PA and lateral direction seems to be less sensitive to breathing than those along inferior-superior direction. Conclusion: The fast spiral CT scanning is sensitive to patient lung motion and can be used to determine the fluctuations of the gross tumor volume with breathing. The extent of the fluctuation is location dependent and increases as one moves from the

Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

Energy Technology Data Exchange (ETDEWEB)

Miller, Julie M.; Vavere, Andrea L.; Arbab-Zadeh, Armin; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Lima, Joao A.C. [Johns Hopkins Hospital, Johns Hopkins University, Department of Medicine, Division of Cardiology, Baltimore, MD (United States); Dewey, Marc [Charite - Universitaetsmedizin Berlin, Medical School, Humboldt-Universitaet und Freie Universitaet zu Berlin, Department of Radiology, Berlin, PO Box 10098 (Germany); Rochitte, Carlos E.; Lemos, Pedro A. [University of Sao Paulo Medical School, Heart Institute (InCor), Sao Paulo (Brazil); Niinuma, Hiroyuki [Iwate Medical University, Department of Cardiology, Morioka (Japan); Paul, Narinder [Toronto General Hospital, Department of Medical Imaging, Toronto (Canada); Hoe, John [Medi-Rad Associates Ltd, CT Centre, Mt Elizabeth Hospital, Singapore (Singapore); Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Yoshioka, Kunihiro [Iwate Medical University, Department of Radiology, Morioka (Japan); Cox, Christopher [Johns Hopkins Bloomberg School of Public Health, Department of Epidemiology, Baltimore, MD (United States); Clouse, Melvin E. [Harvard University, Department of Radiology, Beth Israel Deaconess, Boston, MA (United States)

2009-04-15

Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective ''CORE-64'' trial (''Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors''). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. (orig.)

Clinical application of low-dose spiral CT for orthodontics

International Nuclear Information System (INIS)

Xie Na; Gan Yungen; Shu Huang; Lin FeiFei; Li Zhiyong; Sun Jie

2009-01-01

Objective: To determine the effect of reducing the value of mA or kV on the image quality and the radiation dose of the patients undergoing low-dose spiral CT for orthodontics. Methods: Thirty patients were divided into three groups, each group has 10 patients. They were group 1 (80 kV and 200 mA), group 2 (120 kV and 80 mA), group 3 (120 kV and 200 mA) The volume CT dose index (CTDI) was recorded and the average dose-length produce (DLP) was calculated in three groups,respectively. Image quality of three groups were compared and scored by two radiologists, and the results were statistically analysed. Results: The CTDI and DLP of 80 kV group (group 2) were 8.7 mGy and (36.80 ± 3.60) mGy · cm, respectively, those of 80 mA group (group 3) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively, and those of conventional-dose group (group 1) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively. There was no significant difference among three groups in diagnostic image quality. Conclusions: Low-dose spiral CT for orthodontics, especially the low-kV scan, may decrease the radiation exposure and guarantee the image quality. (authors)

Preliminary feasibility assessment on the investigation of bronchogenic adenocarcinoma angiogenesis with dynamic multi-slice spiral computed tomography

International Nuclear Information System (INIS)

Li Shenjiang; Xiao Xiangsheng; Li Huimin; Liu Shiyuan; Li Chengzhou; Zhang Chenshi; Tao Zhiwei

2003-01-01

Objective: To evaluate the feasibility on the investigation of bronchogenic adenocarcinoma angiogenesis with dynamic multi-slice spiral computed tomography (MSCT) . Methods: 27 patients with bronchogenic adenocarcinomas (diameter ≤4 cm) underwent multi-location dynamic contrast material-enhanced (90 ml, 4 ml/s) serial CT. These dynamic images were processed with the 'time lapse' software and the 'functional CT' software. Peak heights of bronchogenic adenocarcinoma and the aorta, perfusion and mean transit time (MTT) were measured. Ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta was calculated. Perfusion and mean transit time images were obtained. Results: Peak height of bronchogenic adenocarcinoma was (36.66 ± 13.53) HU. No statistically significant difference in the peak height was found between our results and the results of Ukihide et al (mean peak height 34.1 HU) (t =0.981, P = 0.335). Bronchogenic adenocarcinoma-to-aorta ratio was (15.72±4.66 )%. The difference in bronchogenic adenocarcinoma -to-aorta ratio between our results and the results of Zhang and Kono (mean malignant SPN-to-aorta ratio 14.6%) did not reach statistical significance (t=1.244, P=0.225). The mean perfusion value (3.278 ml·min - · kg -1 ) was in the range of that (1.36-2.98 ml·min -1 ·kg -1 ) measured with a single photon emission CT (SPECT). Mean transit time was (17.60 ± 4.52) s. Conclusion: It is feasible to investigate bronchogenic adenocarcinoma angiogenesis with dynamic MSCT

Pulmonary spheral tuberculosis: features and clinical significance of spiral dynamic CT

International Nuclear Information System (INIS)

Xie Ruming; Ma Daqing; Li Tieyi; Chen Yi; Lu Fudong; Zhou Xinhua

2001-01-01

Objective: To assess the features and clinical significance of spiral dynamic CT in patients with pulmonary spheral tuberculosis. Methods: The 54 foci in 42 patients with pulmonary spheral tuberculosis were studied. Thin-sections at 2 mm thickness and 2 mm interval through the nodular center were obtained before and after administration of contrast material. Results: In 54 pulmonary spheral tuberculosis, maximum enhanced CT value in 51 (94.4%, 51/54) foci was less than 20 HU, and more than 20 HU in the other 3(5.6%, 3/54) foci. 27(50.0%, 27/54) foci showed no any enhancement, 24, (44%, 24/54) foci showed capsular enhancement, 1(1.9%, 1/54) focus showed peripheral enhancement and 2(3.7%, 2/54) foci showed extensive enhancement. The accuracy of the correct diagnosis was 25.9% in terms of plain CT and 94.4% in terms of enhanced CT scanning. The difference was significant (x 2 = 50.1, P < 0.05). The curative effect of extensive enhanced foci and peripheral enhanced foci was optimal, capsular enhanced foci was second, and non-enhanced foci was barely satisfactory. Conclusion: Spiral dynamic CT technique may improve the accuracy of diagnosing pulmonary spheral tuberculosis. No enhancement and/or capsular enhancement were suggestive of tuberculosis. The enhancing character of foci might contribute to assess the curative effect of anti-tuberculosis

Multi-slice spiral CT multiplanar reconstruction findings of localized fat collection adjection to the subdiaphragmatic inferior vena cava

International Nuclear Information System (INIS)

Cao Hetao; Lu Jian; Zhao Jinli; Liu Tingting; Qin Jufeng; Xu Wen; Qin Jiangchun; Jiang Junkang

2012-01-01

Objective: To discusses the MSCT multiplanar reconstruction manifestation (MPR) of localized fat collection adjection to subdiaphragmatic inferior vena cava (IVC fat ). Methods: The thoracic and abdominal MSCT scan data of 8246 patients were browsed,45 patients with presumed IVC fat on axial CT scans were further studied prospectively with MSCT MPR. The predisposing position of IVC fat and its relationship with IVC were observed. It was divided into two kinds of intraluminal type and extraluminal type according to the angle of IVC fat with respect of the wall of IVC.The other 50 patients without IVC fat were randomly selected as the control group. The sagittal inclination angle (SIA) and diameter ratio (DR) between supra- and sub-diaphragmatic IVC between the two groups were compared by using t test. Results: The detection rate was 0.55% (45/8246). Of which hepatic vein lacuna 8 patients, subdiaphragmatic gap medial to IVC 28 patients and IVC groove 9 patients. The shape of IVC fat showed mainly for the round, oval and crescents on axial CT scans, of 15 patients intraluminal type, 4 showed 'target signs'. The shape of IVC fat showed mainly for 'half-moon' at MPR.The SIA and DR at IVC fat group were 21.62° ± 8.42° and 2.01 ±0.84 respectively, at control group were 16.75° ±7.82° (t=1.594, P>0.05) and 1.31 ±0.28 (t=2.341, P<0.05) respectively. Conclusion: The round, oval or half of limited fat density shadow adjection to subdiaphragmatic inferior vena cava which similar to in the lumen is the characteristic performance of IVC fat , it may be an anatomical variation. (authors)

Detection of hepatocellular carcinoma with multi-slice spiral CT by ...

African Journals Online (AJOL)

STORAGESEVER

2010-06-07

Jun 7, 2010 ... The purpose of the study is to evaluate the effect of iodine concentration of contrast material on detection of hepatocellular carcinoma with multi-slice spiral computed tomography (CT) by using double-arterial phase and portal venous phase enhanced scanning. Ninety-four (94) patients with hepatocellular ...

Visual classification of emphysema heterogeneity compared with objective measurements: HRCT vs spiral CT in candidates for lung volume reduction surgery

International Nuclear Information System (INIS)

Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B.; Bergstrand, L.; Tylen, U.; Aspelin, P.

2002-01-01

The aim of this study was to investigate whether spiral CT is superior to high-resolution computed tomography (HRCT) in evaluating the radiological morphology of emphysema, and whether the combination of both CT techniques improves the evaluation in patients undergoing lung volume reduction surgery (LVRS). The material consisted of HRCT (with 2-mm slice thickness) and spiral CT (with 10-mm slice thickness) of 94 candidates for LVRS. Selected image pairs from these examinations were evaluated. Each image pair consisted of one image from the cranial part of the lung and one image from the caudal part. The degree of emphysema in the two images was calculated by computer. The difference between the images determined the degree of heterogeneity. Five classes of heterogeneity were defined. The study was performed by visual classification of 95 image pairs (spiral CT) and 95 image pairs (HRCT) into one of five different classes of emphysema heterogeneity. This visual classification was compared with the computer-based classification. Spiral CT was superior to HRCT with 47% correct classifications of emphysema heterogeneity compared with 40% for HRCT-based classification (p<0.05). The combination of the techniques did not improve the evaluation (42%). Spiral CT is superior to HRCT in determining heterogeneity of emphysema visually, and should be included in the pre-operative CT evaluation of LVRS candidates. (orig.)

Visual classification of emphysema heterogeneity compared with objective measurements: HRCT vs spiral CT in candidates for lung volume reduction surgery

Energy Technology Data Exchange (ETDEWEB)

Cederlund, K.; Hoegberg, S.; Rasmussen, E.; Svane, B. [Department of Thoracic Radiology, Karolinska Hospital, Stockholm (Sweden); Bergstrand, L. [Department of Radiology, Danderyds Hospital, Danderyd (Sweden); Tylen, U. [Deparment of Radiology, Sahlgrenska University Hospital, Gothenberg (Sweden); Aspelin, P. [Department of Radiology, Huddinge University Hospital, Huddinge (Sweden)

2002-05-01

The aim of this study was to investigate whether spiral CT is superior to high-resolution computed tomography (HRCT) in evaluating the radiological morphology of emphysema, and whether the combination of both CT techniques improves the evaluation in patients undergoing lung volume reduction surgery (LVRS). The material consisted of HRCT (with 2-mm slice thickness) and spiral CT (with 10-mm slice thickness) of 94 candidates for LVRS. Selected image pairs from these examinations were evaluated. Each image pair consisted of one image from the cranial part of the lung and one image from the caudal part. The degree of emphysema in the two images was calculated by computer. The difference between the images determined the degree of heterogeneity. Five classes of heterogeneity were defined. The study was performed by visual classification of 95 image pairs (spiral CT) and 95 image pairs (HRCT) into one of five different classes of emphysema heterogeneity. This visual classification was compared with the computer-based classification. Spiral CT was superior to HRCT with 47% correct classifications of emphysema heterogeneity compared with 40% for HRCT-based classification (p<0.05). The combination of the techniques did not improve the evaluation (42%). Spiral CT is superior to HRCT in determining heterogeneity of emphysema visually, and should be included in the pre-operative CT evaluation of LVRS candidates. (orig.)

[Application of Low Dose Spiral CT in Diagnosing Impacted Teeth in Children and Adolescents].

Science.gov (United States)

Wang, Meng-tian; Li, Xue-sheng; Li, Kai-ming; Bao, Li; Ning, Gang

2015-09-01

[ABSTRACT] To determine the value of low dose spiral CT scanning in diagnosing impacted teeth of children and adolescents. A total of 153 children and adolescents with confirmed impacted teeth in West China Second University Hospital, Sichuan University were enrolled in this study. They were divided into 5 groups according to the different spiral CT scan parameters (tube current time product, scanning thickness and collimation value): Group A (n=30, 330 mAs, 6 X 0. 75 mm and 3. 0 mm), Group B (n=30, 140 mAs, 6 X 0. 75 mm and 3. 0 mm), Group C (n=30, 80 mAs, 6 X 0. 75 mm and 3. 0 mm), Group D (n=31, 80 mAs, 6 X 1. 50 mm and 5. 0 mm), and Group E (n=32, 50 mAs, 6 X 1. 50 mm and 5. 0 mm). There were no significant differences in general clinical features (P>0. 05) among the participants of the five groups. The phantoms were used to measure spatial resolution and contrast resolution of the scan images. Dose length product (DLP) was recorded during CT scanning for calculating effective dose (ED) of exposure. The quality of images was evaluated using a list of quality scoring criteria. (1) Under 330, 140, 80, 80 and 50 mAs, the images had a spatial resolution of 1.0 mm, with contrast resolution of 2. 0, 3. 0, 4. 5, 4. 5 and 6. 0 mm, respectively. (2) Significant differences in ED values were found among the five groups (F=1 064. 119, P=0. 000) and between every two of those groups (P0. 05). The diagnostic results of the spiral CT were consistent with those of orthodontic surgery. Low dose spiral CT scanning can meet the image quality requirements for diagnosing impacted teeth, minimizing radiation exposure effectively.

A study of parameters in spiral CT volumetry using balloon phantoms

International Nuclear Information System (INIS)

Lee, Hak Jong; Han, Joon Koo

2001-01-01

To evaluate the effects of threshold values, reconstruction interval, slice thickness and table speed on the spiral CT volumetry. Two phantoms made of a balloon and diluted contrast media underwent spiral CT scanning with section thicknesses of 5, 7 and 10 mm and table speeds of 5, 8 and 10 mm with scans of 5 mm section thickness, 7, 10, and 14 mm with scans of 7 mm section thickness, and 10, 15, and 20 mm with scans of 10 mm section thickness. The volumetric values of phantom A and B were obtained at varying threshold values and a reconstruction interval of 5 and 10 mm for all scans. Volumes were also determined with the threshold value fixed and a reconstruction interval of 1, 5, 7 and 10 mm, respectively. Three-dimensional display and volumetric measurements were obtained using reconstructed images. The effects of threshold value, reconstruction interval, slice thickness and table speed on volumetry were analyzed. Volumetric values varied according to threshold values. Where a threshold value was low, value increased as pitch increased, but where a the threshold value was high, value decreased as pitch increased. With varying threshold values, measurement errors in CT volumetry were 1.6 to 9.0%. Volume decreased as reconstruction interval increased. Where the table speed/ slice thickness ratio was constant, volume was constant though slice thickness differed. At fixed threshold values, variation in the reconstruction interval was statistically more significant than variation in slice thickness or table speed (p<0.05, Kruskal-Wallis one-way ANOVA). Among serveral spiral scanning and image reconstruction parameters including threshold value, reconstruction interval, slice thickness, and table speed, threshold value most affected the result obtained. At fixed threshold values, the reconstruction interval used had more effect on CT volumetry than other parameters

MSCT diagnosis of pulmonary embolism

International Nuclear Information System (INIS)

Fang Jie; Yang Li; Zhang Ailian; Li Gongjie; Ren Shuanqun

2004-01-01

Objective: To analyze the distribution and size of intraluminal filling defects and corresponding parenchymal findings in pulmonary embolism (PE) on MSCT. Methods: Twelve PE cases diagnosed by spiral CTA were retrospected. The involved pulmonary arteries according to presence of filling defects were classified as central, peripheral and mixed type. Lobular pulmonary artery with filling defects classified as complete defect and partial defects. The presence or absence of parenchymal abnormalities and pleural effusion was noted. Results: Peripheral PE was identified in 2 of the 12 patients with PE, and others were with mixed type. Anatomic evaluation of filling defects at lobular level revealed a total of 25 arteries in 12 patients including 9 with complete filling defect and 16 with partial filling defect. Only 3 cases were found to have parenchyma consolidation from all the 12 cases, and 1 case was diagnosed as pneumonia. Pleural effusion was seen in 4 cases. Conclusion: Parenchymal changes in PE do not often take place and lack specified signs. Diagnosis of PE is based on conformation of parenchymal changes with occluded segment of pulmonary arteries. Clinical history and follow up are of very importance in defining parenchyma change arose from PE. (authors)

Comparison of scatter doses from a multislice and a single slice CT scanner

International Nuclear Information System (INIS)

Burrage, J. W.; Causer, D. A.

2006-01-01

During shielding calculations for a new multislice CT (MSCT) scanner it was found that the manufacturer's data indicated significantly higher external scatter doses than would be generated for a single slice CT (SSCT). Even allowing for increased beam width, the manufacturer's data indicated that the scatter dose per scan was higher by a factor of about 3 to 4. The magnitude of the discrepancy was contrary to expectations and also contrary to a statement by the UK ImPACT group, which indicated that when beam width is taken into account, the scatter doses should be similar. The matter was investigated by comparing scatter doses from an SSCT and an MSCT. Scatter measurements were performed at three points using a standard perspex CTDI phantom, and CT dose indices were also measured to compare scanner output. MSCT measurements were performed with a 40 mm wide beam, SSCT measurements with a 10 mm wide beam. A film badge survey was also performed after the installation of the MSCT scanner to assess the adequacy of lead shielding in the room. It was found that the scatter doses from the MSCT were lower than indicated by the manufacturer's data. MSCT scatter doses were approximately 4 times higher than those from the SSCT, consistent with expectations due to beam width differences. The CT dose indices were similar, and the film badge survey indicated that the existing shielding, which had been adequate for the SSCT, was also adequate for the MSCT

Abdominal spiral CT in children: which radiation exposure is required?

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Wormanns, D.; Diederich, S.; Lenzen, H.; Ludwig, K.; Papke, Karsten; Hagedorn, Claudia; Heindel, Walter [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie; Lange, P.; Link, T.M. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie; Dept. of Radiology, Technical Univ. Muenchen (Germany)

2001-11-01

We decided to test to what extent dose reduction is possible in abdominal spiral computed tomography (CT) in young children without loss of anatomic diagnostic information. A retrospective study was performed of 30 abdominal CT examinations of children aged 3 months to 7 years. These were divided into two groups: group A with reduced radiation exposure (tube current 50 mA, CT dose index CTDI{sub FDA} {<=}0.83 mGy) and group B with standard radiation exposure (tube current {>=}100 mA, CTDI{sub FDA} {>=}1.66 mGy). Image quality was assessed using a four-part scale ('excellent', 'good', 'sufficient', 'poor') on visual image impression and visibility of 32 anatomical details. Five experienced radiologists read the CT scans independently who were blinded to the examination parameters. Differences in ranked data were evaluated with Wilcoxon's rank sum test. No difference between groups A and B was observed in visual image impression. Detail visibility was significantly lower in group A, but the differences were limited to right upper quadrant structures (portal vein, common bile duct, pancreatic head, adrenals) and to arterial branches. Significant differences in visibility rated as 'poor' were only found for the hepatic, splenic and renal arteries; all other structures showed no difference between groups A and B. A protocol with reduced radiation exposure (50 mA, CTDI{sub FDA} {<=}0.83 mGy) allowed the demonstration of most anatomic structures in abdominal spiral CT in young children. For the precise demonstration of small details (e.g. structures of the right upper quadrant), a protocol with standard radiation exposure ({>=}100 mAs) was superior. (orig.)

CT pulmonary angiography using 64-row multi-slice spiral CT: a comparative study in low tube voltage setting combined with personalized contrast agent application

International Nuclear Information System (INIS)

Zhou Xuhui; Peng Zhenpeng; Zheng Lili; Li Shurong; Yang Zhiyun; Meng Quanfei; Chen Xing

2009-01-01

Objective: To investigate the feasibility of the low tube voltage setting and personalized contrast agent application in 64-row multi-slice spiral CT pulmonary angiography. Methods: Ninety patients with high risk of pulmonary artery embolism were sequentially enrolled in the study and divided into 3 groups employing completely randomized design: (l)Regular group included 30 patients using 120 kV and fixed dose of 70 ml contrast agent, (2)Another 30 patients were in 120 kV group, using 120 kV and the contrast amount was determined according to the patient weight (1.0 ml/kg), (3) The remaining 30 patients were included in 100 kV group, using 100 kV and the contrast amount was also determined according to the patient weight(1.0 ml/kg). Administration of contrast agent was completed within 20 seconds for all the patients, followed by 20 ml of saline. The objective and subjective indexes for assessing CT image quality, CT dose index volume (CTDIvol) and effective received dose (ERD) were compared between 120 kV group and 100 kV group; then the contrast media volume, injection rate, objective CT image indexes and subjective indexes for image quality was compared between the 100 kV group and regular group. The variance analysis and post hoc test were employed for the statistical analysis. Results: Compared with 120 kV group (3.4±0.7), the image quality of 100 kV group (5.2±1.8) had higher noise (52.9%), but subjective index for the image quality demonstrated no differences (q=0.272, P=0.063) in mediastinum window while CTDIvol and ERD decreased for 34.9% [(9.5±0.0) vs (14.6±0.0) mGy] and 36.8% [(3.8±0.6) vs (2.4±0.4) mSv]. The mean CT values on pulmonary artery of 100 kV group[ (269.2±54.7) HU] were 13.4% (31.8/237.4) higher than the 120 kV group [(237.4±62.9)HU], but there was no statistical differences compared to normal group (q=0.172,P=0.260). Conclusion: Using low kV setting (100 kV) to reduce radiation dose is proved to be effective and feasible in 64-MSCT

Three-dimensional spiral CT of craniofacial malformations in children

International Nuclear Information System (INIS)

Binaghi, S.; Gudinchet, F.

2000-01-01

Objective. To assess the value of three-dimensional CT (3D CT) in the diagnosis and management of suspected paediatric craniofacial malformations. Materials and methods. Twenty-eight children (12 girls, 16 boys) with a mean age of 4 years, suffering from craniofacial or cervical malformations, underwent craniofacial spiral CT. 3D reformatting was performed using an independent workstation. Results. 3D CT allowed the preoperative evaluation of 16 patients with craniosynostosis and the post-surgical management of 2 patients. 3D CT clearly depicted malformations of the skull base involving the petrous bone in seven patients (four cases of Goldenhar-Gorlin syndrome, one case of Treacher-Collins syndrome and two cases of Crouzon's disease). Four patients with craniofacial clefts were also evaluated. Radiological findings were confirmed by the clinical and intraoperative findings in all patients that underwent surgical treatment. Movement artefacts and ''Lego effect'' related to abrupt change of cranial vault border were encountered and are discussed. Conclusions. 3D CT of the skull can safely and reliably identify paediatric craniofacial malformations involving bone, and it should be used as morphological mapping to help the surgeon in planning surgical treatment. (orig.)

Effective dose estimation in whole-body multislice CT in paediatric trauma patients

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Munk, Robin D.; Saueressig, Ulrich; Kotter, Elmar; Langer, Mathias; Bley, Thorsten A. [University Hospital, Department of Radiology, Freiburg im Breisgau (Germany); Strohm, Peter C.; Zwingmann, Joern; Suedkamp, Norbert P. [University Hospital, Department of Orthopaedic and Trauma Surgery, Freiburg im Breisgau (Germany); Uhl, Markus [University Hospital, Department of Radiology, Section of Paediatric Radiology, Freiburg im Breisgau (Germany)

2009-03-15

The number of multislice CT (MSCT) scans performed in polytraumatized children has increased rapidly. There is growing concern regarding the radiation dose in MSCT and its long-term consequences, especially in children. To determine the effective dose to polytraumatized children who undergo whole-body MSCT. A total of 51 traumatized children aged 0-16 years underwent a polytrauma protocol CT scan between November 2004 and August 2006 at our institution. The effective dose was calculated retrospectively by a computer program (CT-Expo 1.5, Hannover, Germany). The mean effective dose was 20.8 mSv (range 8.6-48.9 mSv, SD{+-}7.9 mSv). There was no statistically significant difference in the effective dose between male and female patients. Whole-body MSCT is a superior diagnostic tool in polytraumatized children with 20.8 mSv per patient being a justified mean effective dose. In a potentially life-threatening situation whole-body MSCT provides the clinicians with relevant information to initiate life-saving therapy. Radiologists should use special paediatric protocols that include dose-saving mechanisms to keep the effective dose as low as possible. Further studies are needed to examine and advance dose-saving strategies in MSCT, especially in children. (orig.)

Spiral CT in kidney: assumption of renal function by objective evaluation of renal cortical enhancement

International Nuclear Information System (INIS)

Choi, Bo Yoon; Lee, Jong Seok; Lee, Joon Woo; Myung, Jae Sung; Sim, Jung Suk; Seong, Chang Kyu; Kim, Seung Hyup; Choi, Guk Myeong; Chi, Seong Whi

2000-01-01

To correlate the degree of renal cortical enhancement, objectively evaluated by means of spiral CT with the serum level of creatinine, and to determine the extent to which this degree of enhancement may be used to detect renal parenchymal disease. Eighty patients (M:F = 50:30; age + 25-19, (mean 53) years) with available serum level of creatinine who underwent spiral CT between September and October 1999 were included in this study. In fifty patients the findings suggested hepatic or biliary diseases such as hepatoma, biliary cancer, or stone, while in thirty, renal diseases such as cyst, hematoma, or stone appeared to be present. Spiral CT imaging of the cortical phase was obtained at 30-40 seconds after the injection of 120 ml of non-ionic media at a rate of 3 ml/sec. The degree of renal cortical enhancement was calculated by dividing the CT attenuation number of renal cortex at the level of the renal hilum by the CT attenuation number of aorta at the same level. The degree of renal cortical enhancement was compared with the serum level of creatinine, and the degree of renal cortical enhancement in renal parenchymal disease with that of the normal group. Among eighty patients there were five with renal parenchymal disease and 75 with normal renal function. The ratio of the CT attenuation number of renal cortex to that of aorta at the level of the renal hilum ranged between 0.49 and 0.99 (mean, 0.79; standard deviation, 0.15). while the serum level of creatinine ranged between 0.6 and 3.2 mg/dl. There was significant correlation (coefficient of -0.346) and a statistically significant probability of 0.002 between the ratio of the CT attenuation numbers and the serum level of creatinine. There was a significant difference (statistically significant probability of less than 0.01) between those with renal parenchymal disease and the normal group. The use of spiral CT to measure the degree of renal cortical enhancement provides not only an effective index for

Spiral CT and optimization of the modalities of the iodinated intravenous contrast material: Experimental studies in human pathology

International Nuclear Information System (INIS)

Bonaldi, V.

1998-01-01

Spiral (or helical) CT represents the most recent improvement in the field of computed assisted tomography (CAT scan). The capabilities of this new imaging modality are much superior to these of conventional CT scanning; then result from the rapid acquisition and from the volumetric nature of the derived data set. The short time of data acquisition had made mandatory the revision of protocols for intravenous administration of iodinated contrast material. By the means of several studies, carried out on pathologic and healthy patients, we have attempted to improve knowledge in factors influencing CT attenuation values after injection of contrast material, in the aim of improving contrast administration performed during spiral CT scanning. Anatomical landmarks that we have studied till now have been liver, the pancreas, the kidney and the cervical spine. In addition, a paired based methodology has been used. The volumetric set of data derived from spiral CT scanning leads to optimal post-processing tasks, the most interesting being related to cine-display and multiplanar reformatting; both modalities have been evaluated, about the pancreas and the musculo-skeletal system respectively. Conversely, this new modality, as for other imaging modalities, is responsible for additional costs derived from restless increase in the number of images to be dealt with and from the occurrence of new tasks (in post-processing particularly). The place of spiral CT in diagnostic strategies among other modern imaging modalities should be assessed, especially with respect to Magnetic Resonance Imaging (MRI). (author)

Spiral CT scanning technique in the detection of aspiration of LEGO foreign bodies.

Science.gov (United States)

Applegate, K E; Dardinger, J T; Lieber, M L; Herts, B R; Davros, W J; Obuchowski, N A; Maneker, A

2001-12-01

Radiolucent foreign bodies (FBs) such as plastic objects and toys remain difficult to identify on conventional radiographs of the neck and chest. Children may present with a variety of respiratory complaints, which may or may not be due to a FB. To determine whether radiolucent FBs such as plastic LEGOs and peanuts can be seen in the tracheobronchial tree or esophagus using low-dose spiral CT, and, if visible, to determine the optimal CT imaging technique. Multiple spiral sequences were performed while varying the CT parameters and the presence and location of FBs in either the trachea or the esophagus first on a neck phantom and then a cadaver. Sequences were rated by three radiologists blinded to the presence of a FB using a single scoring system. The LEGO was well visualized in the trachea by all three readers (both lung and soft-tissue windowing: combined sensitivity 89 %, combined specificity 89 %) and to a lesser extent in the esophagus (combined sensitivity 31 %, combined specificity 100 %). The peanut was not well visualized (combined sensitivity LEGO was 120 kV, 90 mA, 3-mm collimation, 0.75 s/revolution, and 2.0 pitch. This allowed for coverage of the cadaver tracheobronchial tree (approximately 11 cm) in about 18 s. Although statistical power was low for detecting significant differences, all three readers noted higher average confidence ratings with lung windowing among 18 LEGO-in-trachea scans. Rapid, low-dose spiral CT may be used to visualize LEGO FBs in the airway or esophagus. Peanuts were not well visualized.

Evaluation of experimental cartilage lesions with ultrahigh-resolution multi-slice-CT in comparison to histology

International Nuclear Information System (INIS)

Stork, A.; Kemper, J.; Begemann, P. G. C.; Habermann, C.R.; Adam, G.; Priemel, M.; Kummer, T.; Amling, M.

2004-01-01

Purpose: histologic validation of ultrahigh-resolution multislice (MS)-CT for the evaluation of focal, experimental cartilage lesions with special regard to the subchondral bone. Testing of micro-CT (μCT) as alternative reference standard. Methods: 32 experimental cartilage lesions in bovine patellae were imaged surrounded by air (MS-CT-air) and immersed in a contrast material solution (MS-CT-CM) with MS-CT (collimation 2 x 0,5 mm). After the μCT (8 μm-voxelsite) examination in three specimen and histologic work-up of 29 specimen two radiologist graded the defects on MS-CT images in consensus (subchondral bone involvement yes or no) and results were compared to the results of histomorphometry and μCT. Results: the MS-CT-air and -CM had an accuracy of 94% (30/32) and 88% (28/32), respectively. MS-CT-air led to one false-positive (remaining cartilage: = 0,1 mm) and false-negative result, each. MS-CT-CM showed false-positive results if the remaining cartilage was [de

Establishment of an orthotopic lung cancer model in nude mice and its evaluation by spiral CT.

Science.gov (United States)

Liu, Xiang; Liu, Jun; Guan, Yubao; Li, Huiling; Huang, Liyan; Tang, Hailing; He, Jianxing

2012-04-01

To establish a simple and highly efficient orthotopic animal model of lung cancer cell line A549 and evaluate the growth pattern of intrathoracic tumors by spiral CT. A549 cells (5×10(6) mL(-1)) were suspended and inoculated into the right lung of BALB/c nude mice via intrathoracic injection. Nude mice were scanned three times each week by spiral CT after inoculation of lung cancer cell line A549. The survival time and body weight of nude mice as well as tumor invasion and metastasis were examined. Tissue was collected for subsequent histological assay after autopsia of mice. The tumor-forming rate of the orthotopic lung cancer model was 90%. The median survival time was 30.7 (range, 20-41) days. The incidence of tumor metastasis was 100%. The mean tumor diameter and the average CT value gradually increased in a time-dependent manner. The method of establishing the orthotopic lung cancer model through transplanting A549 cells into the lung of nude mice is simple and highly successful. Spiral CT can be used to evaluate intrathoracic tumor growth in nude mice vividly and dynamically.

The anal verge: localization with multi-slice spiral CT

International Nuclear Information System (INIS)

Wang Wei; Tang Guangjian

2010-01-01

Objective: To determine and evaluate the method of localization of anal verge by multislice spiral CT. To provide an imaging reference for operative guidance of low-rectal cancer. Methods Forty eight consecutive adult patients suspected of abnormalities other than rectal disease were evaluated with abdominal and pelvic CT scans since August, 2009. They were divided into two groups based on sex and age. There were 23 men and 25 women. The ages of young group were 28 to 50 years and the average age was 41 years. The ages of elderly group were 52 to 81 years and the average age was 64 years. A small cotton ball dipped with contrast media was put at the anal verge as a marker and CT scans were performed with 64-slice spiral CT scanner. The distances between the cotton balls and the lower margin of the pubis combination (La), the lower margin of the Sth sacral vertebra (Lb), the inferior aperture of minor pelvis (Lc) and the lower margin of the basement of external anal sphincter (Ld) were measured on the mid- sagittal images obtained by MPR. The averages, the standard deviations (s), the 95% and 80% confidence intervals of La, Lb, Lc and Ld were calculated. We took the intervals of ±1.96 s or ±1.28 s 0.05) between two different sex groups [male group, (10.0±1.2) mm], female group, (9.6±1.2) mm and between two age groups [young group, (9.6±1.2) mm, elderly group, (9.9±1.3) mm]. Conclusions: The lower margin of the basement of external anal sphincter was a useful anatomic landmark for localizing the anal verge, and could be definitely identified on the middle sagittal pelvic CT image. The distance between the structure and anal verge is constant enough and can be used in measuring distance from low rectal lesion to the anal verge. (authors)

Borrmann type IV adenocarcinoma versus gastric lymphoma : spiral CT evaluation

International Nuclear Information System (INIS)

Seo, Bo Kyoung; Kim, Yun Hwan; Shin, Kue Hee; Hong, Suk Joo; Kim, Hong Weon; Park, Cheol Min; Chung, Kyoo Byung; Cho, Hyun Deuk

1999-01-01

To distinguish the spiral CT findings of Borrmann type IV adenocarcinoma from those of gastric lymphoma with diffuse gastric wall thickening. We retrospectively reviewed the spiral CT scans of 30 patients with Borrmann type IV adenocarcinoma and nine with gastric lymphoma with diffuse gastric wall thickening. In all patients the respective condition was pathologically confirmed by gastrectomy. CT scanning was performed after peroral administration of 500-700ml of water. A total of 120-140 ml bolus of nonionic contrast material was administered intravenously at a flow rate of 3 ml/sec and two-phase images were obtained at 35-45 sec(early phase) and 180 sec(delayed phase) after the start of bolus injection. Spiral CT was performed with 10mm collimation, 10mm/sec table feed and 10mm reconstruction. We evaluated the degree and homogeneity of enhancement of thickened entire gastric wall, and the enhancement pattern of gastric inner layer, as seen on early-phase CT scans. On early and delayed views, the thickness of gastric wall and the presence of perigastric fat infiltration were determined. The enhancement patterns of gastric inner layer were classified as either continuous or discontinuous thick enhancement, thin enhancement, or nonenhancement. The thickness of gastric wall was 1.2-3.5cm(mean 2.2cm) in cases of adenocarcinoma and 1.2-7.6cm(mean 4cm) in lymphoma. Perigastric fat infiltration was seen in 24 patients with adenocarcinoma(80%) and four with lymphoma(44%). In those with adenocarcinoma, the degree of enhancement of entire gastric wall was hyperdense in fifteen patients(50%) and isointense in eleven (37%). Seven patients with lymphoma(78%)showed hypodensity. In those with adenocarcinoma, continuous thick enhancement of gastric inner layer was seen in 18 patients(60%) and discontinuous thick enhancement in nine(30%). In lymphoma cases, no thick enhancement was observed. Thin enhancement of gastric inner layer was demonstrated in three patients with

Clinical application of 16-slice spiral CT in reconstruction imaging of coronary artery for diagnosing coronary disense

International Nuclear Information System (INIS)

Mao Xinbo; Zhu Xinjin; Zeng Huiliang; Chen Xueguang

2005-01-01

Objective: An evaluation of the reconstructed imaging of coronary arteries with 16-slice spiral CT in diagnosis of coronary disease. Methods: The reconstructed images of coronary arteries obtained on a 16-slice spiral CT scanner were reviewed in 60 cases, on which the following techniques were applied: retrospective ECG-gating, Segment method with 75% R-R interval, volume rendering technique (VRT), maximum intensity projection (MIP), mulfiplanar reconstruction (MPR), curved planar reconstruction (CPR) and CT virtual endoscopy (CTVE). Results: In all 60 cases, different stages of CHD were revealed in 21 cases; none abnormality was found in 33; and images were in poor quality in 2 cases, which was available for diagnosis. There were 4 stents planted in 4 cases: soft plaque suspected in lcase, patent in 2 and occlude in 1. Conclusion: The reconstructed imaging of coronary arteries with 16-slice spiral CT is superior modality in evaluation of severe coronary stenosis, plaques, and the pantency of the intra-luminal stents, which is an efficient and non-invasive imaging in diagnosis of early-stage CHD and screening in high risk population. (authors)

The diagnostic value of multi-slice spiral CT virtual bronchoscopy in tracheal and bronchial disease

International Nuclear Information System (INIS)

Han Ying; Ma Daqing

2006-01-01

Objective: To assess the diagnostic value of multi-slice spiral CT virtual bronchoscopy (CTVB) in tracheal and bronchial disease. Methods: Forty-two patients including central lung cancer (n=35), endobronchial tuberculosis (n=3), intrabronchial benign tumor (n=3), and intrabronchial foreign body (n=1) were examined by using multi-slice spiral CT examinations. All the final diagnosis were proved by pathology except 1 patient with endoluminal foreign body was proved by clinic. All patients were scanned on GE Lightspeed 99 scanner, using 10 mm collimation, pitch of 1.35, and reconstructed at 1 mm intervals and 1.25 mm thickness. The chest images of transverse CT and virtual bronchoscopy were viewed by two separate radiologists who were familiar with the tracheal and bronchial anatomy. Results: Among the 42 patients, the tumor of trachea and bronchial lumen appeared as masses in 22 of 35 patients with central lung cancer and bronchial stenosis was found in 13 of 35 patients with central lung cancer, and bronchial wall thickening was revealed on transverse CT in all 35 cases. 3 patients of endobronchial tuberculosis showed bronchial lumen narrowing on CTVB, the bronchial wall thickening was revealed on transverse CT, and the length of the wall thickening was long. 3 patients with intrabronchial benign tumor showed nodules in trachea and bronchial lumen on CTVB, and without wall thickening on transverse CT. CTVB could detect the occlusion of bronchial lumen in 1 patient with intrabronchial foreign body and CTVB was able to visualize the areas beyond stenosis, and the bronchial wall was without thickening on transverse CT. Conclusion: Multi- slice spiral CTVB could reflect the morphology of tracheal and bronchial disease. Combined with transverse CT, it could provide diagnostic reference value for bronchial disease. (authors)

Volume-artifact reduction modality by helical CT of the anterior, middle and posterior carnial fossae. Comparison with conventional CT; Volumen-Artefakt-Reduktionstechnik mittels Spiral-CT in der vorderen, mittleren und hinteren Schaedelgrube. Vergleich mit der konventionellen kranialen CT

Energy Technology Data Exchange (ETDEWEB)

Dorenbeck, U.; Finkenzeller, T.; Hill, K.; Feuerbach, S.; Link, J. [Regensburg Univ. (Germany). Inst. fuer Roentgendiagnostik

2000-04-01

Purpose: The object of this study was to determine the extent to which a new volume-artifact reduction (VAR) modality using helical CT was able to reduce artifacts in the anterior, middle and posterior fossae in comparison with conventional CT (sequential mode). Methods: In a prospective, randomized trial, 50 patients underwent helical CT (VAR) and 50 underwent sequential CT. The results were evaluated by three radiologists; influences on image quality where scaled between 1 (no artifact) and 4 (not assessable). Eight regions of the anterior, middle and posterior fossae were evaluated. Results: On average, artifacts were scaled at 2.5 in helical CT (VAR) and 3.1 in conventional CT. Significant differences were seen at the eyeball, anterior to the petrosol bone, at the internal occipital crest, and at the level of the transverse sinus (p<0.005). Conclusions: Helical CT with the VAR modality is superior to conventional, sequential CT in the area of the anterior, middle and posterior fossae. (orig.) [German] Ziel: Das Ziel dieser Studie war herauszufinden, inwieweit ein neuer Volumen-Artefakt-Reduktionsmodus (VAR) im Spiral-CT in der vorderen, mittleren und hinteren Schaedelgrube gegenueber der Einzelschicht-CT zu einer Artefaktverringerung beitragen kann. Methoden: In einer prospektiven randomisierten Studie wurden 50 Untersuchungen mit Spiral-CT und 50 mit Einzelschicht-CT bezueglich Artefakten verglichen. Die Auswertung erfolgte durch drei Radiologen, die Bildqualitaet wurde in einer Skala zwischen 1 (kein Artefakt) und 4 (Beurteilung der Region wegen Artefakten nicht moeglich) angegeben. Acht anatomische Regionen in der vorderen, mittleren und hinteren Schaedelgrube wurden auf Beeintraechtigung durch Artefakte untersucht. Ergebnisse: Im Durchschnitt betrug die Bewertung fuer die Artefaktbeeintraechtigung beim Spiral-CT (VAR) 2,5 gegenueber 3,1 bei der Einzelschicht-CT. Der VAR-Modus ermoeglichte in der mittleren und hinteren Schaedelgrube sowie im Balbus oculi

Risk-benefit analysis and cost-effectiveness analysis of lung cancer screening by spiral CT

International Nuclear Information System (INIS)

Iinuma, Takeshi

1999-01-01

Mass screening of lung cancer has been widely performed using indirect chest X-ray method in Japan. However reduction of the mortality for lung cancer is questioned. We have proposed that recently developed spiral CT should be adopted for the screening of lung cancer, since CT has an excellent detectability for small nodule. Lung Cancer Screening CT (LSCT) has been developed by author's group using spiral CT with low dose and light weight in order to make a mobile unit. In this paper risk-benefit analysis and cost-effectiveness analysis are described for the LSCT screening of lung cancer. As a risk, radiation carcinogenesis due to exposure from LSCT are compared with gain of life-expectancy by screening and men of 40 years or more and women of 45 years or more are justified. The cost per person-year is estimated for LSCT screening which is better than that of present method, although total cost is higher. The LSCT screening could be recommended if total cost is affordable. (author)

Pulmonary emphysema quantitation with Computed Tomography. Comparison between the visual score with high resolution CT, expiratory density mask with spiral CT and lung function studies

International Nuclear Information System (INIS)

Zompatori, Maurizio; Battaglia, Milva; Rimondi, Maria Rita; Vivacqua, Donatella; Biscarini, Manuela; Fasano, Luca; Pacilli, Angela Maria Grazia; Guerrieri, Aldo; Fabbri, Mario; Cavina, Mauro

1997-01-01

CT is the most accurate method to detect pulmonary emphysema in vivo. They compared prospectively two different methods for emphysema quantitation in 5 normal volunteers and 20 consecutive patients with chronic obstructive pulmonary disease (COPD). All subjects were submitted to function tests and HRCT; three scans were acquired at preselected levels during inspiration. The type and extent of pulmonary emphysema were defined by two independent observers under blind conditions. Disagreements were subsequently settled by consent. All subjects were also examined with expiratory spiral CT using a density mask program, at two different cut-off levels (-850,-900 HU). Visual score and expiratory spiral density mask values (-850 HU) were significantly correlated (r = 0.86), but the visual extent of emphysema was always higher than shown by expiratory spiral CT. The emphysema extent assessed with both CT methods correlated with the function result of expiratory airflow obstruction and gas diffusion impairment (visual score versus forced expiratory volume in one second: r = -0.81, versus single breath carbon monoxide diffusion: r = -0.78. Spiral expiratory density mask -850 HU versus forced expiratory volume in one second: r = -0.85 versus single breath carbon monoxide diffusion: r = -0.77). When -900 HU was used as the cut-off value for the expiratory density mask, the correlation with single breath carbon monoxide diffusion worsened (r = -0.56). Visual score and expiratory density mask -850 HU gave similar results and permitted COPD patients to be clearly distinguished from normal controls (p < 0.01). They believe the true residual volume should lie somewhere in between the CT value and the function results with the helium dilution technique and conclude that the extent of pulmonary emphysema can be confidently assessed with CT methods. Finally, the simple visual score may be as reliable as such highly sophisticated new methods as the spiral expiratory density mask

Three phase spiral liver Scanning

International Nuclear Information System (INIS)

Kanyanja, T.A.

2006-01-01

The ability to perform rapid back-to-back spiral acquisitions is an important recent technical advantage of spiral CT. this allows imaging of the upper abdomen (liver) during peak arterial enhancement (arterial phase) and during peak hepatic parenchymal enhancement (portal venous phase). Breatheld spiral CT has completely replaced dynamic incremental CT for evaluation of the liver. in selected patients with hyper vascular metastasis (hepatoma, neuroendocrine tumors, renal cell carcinoma, etc.) a biphasic examination is performed with one spiral acquisition obtained during the hepatic arterial phase and a second acquisition during the portal venous phase

Spiral CT scanning technique in the detection of aspiration of LEGO foreign bodies

International Nuclear Information System (INIS)

Applegate, K.E.; Dardinger, J.T.; Herts, B.R.; Davros, W.J.; Obuchowski, N.A.; Lieber, M.L.; Maneker, A.

2001-01-01

Background:. Radiolucent foreign bodies (FBs) such as plastic objects and toys remain difficult to identify on conventional radiographs of the neck and chest. Children may present with a variety of respiratory complaints, which may or may not be due to a FB. Objective: To determine whether radiolucent FBs such as plastic LEGOs and peanuts can be seen in the tracheobronchial tree or esophagus using low-dose spiral CT, and, if visible, to determine the optimal CT imaging technique. Materials and methods: Multiple spiral sequences were performed while varying the CT parameters and the presence and location of FBs in either the trachea or the esophagus first on a neck phantom and then a cadaver. Sequences were rated by three radiologists blinded to the presence of a FB using a single scoring system. Results: The LEGO was well visualized in the trachea by all three readers (both lung and soft-tissue windowing: combined sensitivity 89 %, combined specificity 89 %) and to a lesser extent in the esophagus (combined sensitivity 31 %, combined specificity 100 %). The peanut was not well visualized (combined sensitivity < 35 %). The optimal technique for visualizing the LEGO was 120 kV, 90 mA, 3-mm collimation, 0.75 s/revolution, and 2.0 pitch. This allowed for coverage of the cadaver tracheobronchial tree (approximately 11 cm) in about 18 s. Although statistical power was low for detecting significant differences, all three readers noted higher average confidence ratings with lung windowing among 18 LEGO-in-trachea scans. Conclusion: Rapid, low-dose spiral CT may be used to visualize LEGO FBs in the airway or esophagus. Peanuts were not well visualized. (orig.)

Different contrast injection protocols for 64-slice spiral CT coronary angiography

International Nuclear Information System (INIS)

Lu Jinguo; Lv Bing; Bai Hua; Tang Xiang; Yang Xinling; Jiang Shiliang; Dai Ruiping; Qiu Jinhai; Chen Tao

2008-01-01

Objective: To determine the optimal contrast protocols for 64-slice spiral CT coronary angiography in order to reduce the volume of contrast injection. Methods: One hundred fifty patients scheduled to undergo 64-slice spiral CT coronary angiography were prospectively randomized into the following five groups with different injection protocols: group 1: uniphasic injection without a flush; group 2: biphasic injection with a flush; group 3, group 4 and group 5 : triphasic injection with a diluted contrast material with 3:7, 5:5, 7:3 contrast/saline ratio respectively. Attenuation was measured in the right atrium, right ventricle, left atrium, left ventricle, ascending aorta, right coronary artery and left coronary artery and analyzed with single factor variance test (ANOVA). The quality of the coronary artery images was evaluated and compared using person Chi-Square. Results: The total contrast material volume were (67.0±5.3) ml, (59.9±4.9) ml, (62.9±3.2) ml, (69.2±5.7) ml and (70.9±4.6) ml in five groups respectively (F=27.43, P 2 =18.81, P 2 =31.44, P<0.01). The artifacts in the superior vena cava in group 1 was the most, and in group 2 was the least. The mean enhancement values of right and left coronary arteries in group 2 were significantly greater than those in other groups (F=2.47 and 4.10, P<0.05). The visualization of both left ventricle and right ventricle cavities was the best in group 3. Conclusion: Biphasic injection and triphasic injection are better than uniphasic injection for 64-slice spiral CT coronary angiography and triphasic injection is better than biphasic injection for the visualization of both left ventricle and right ventricle cavities. (authors)

The usefulness of levin tube inserted drip infusion spiral CT: comparison with conventional method in subtotal gastrectomy patients

International Nuclear Information System (INIS)

Park, Young Jin; Kim, Young Hwan; Yoon, Jung Hee; Cha, Soon Joo; Kim, Jeong Sook; Kim, Sung Rok; Hur, Gham; Rhim, Hyun Chul

1998-01-01

The purpose of this study is to access the usefulness of newly designed Levin tube inserted drip infusion spiral CT for the evaluation of remnant stomach and anastomosis site in patients who have undergone subtotal gastrectomy for stomach cancer. A new technique named Levin tube inserted drip infusion spiral CT was used to prospectively study 23 patients. A 16Fr Levin tube was inserted into the remnant stomach; 500 ml of tap water was drip infused just before CT scanning and an additional 500 ml of water was infused during IV contrast injection. Water was infused by gravity, using a water bottle suspended at a height of 90 cm (Group A). The 31 patients who underwent conventional spiral CT scanning immediately after the divided ingestion of 900 ml diluted gastrografin were selected as a control group (Group B). The anatomic delineation of the anastomosis site was graded by two radiologists as excellent (3), good(2), fair (1) or poor (0). To evaluate the degree of distension, the maximal diameters of remnant stomach and the anastomosis site, and the thickness of the stomach wall, were also measured. In patients who had undergone subtobal gastrectomy, Levin tube inserted drip infusion spiral CT showed excellent anatomic delineation of the site of anastomosis and remnant stomach. We found that because it increases the distension of remnant stomach and the anastomosis site, this technique is effective for the evaluation of postoperative stomach. (author). 10 refs., 2 tabs., 3 figs

CT fluoroscopy-guided vs. multislice CT biopsy mode-guided lung biopsies: Accuracy, complications and radiation dose

International Nuclear Information System (INIS)

Prosch, Helmut; Stadler, Alfred; Schilling, Matthias; Bürklin, Sandra; Eisenhuber, Edith; Schober, Ewald; Mostbeck, Gerhard

2012-01-01

Background: The aim of this retrospective study was to compare the diagnostic accuracy, the frequency of complications, the duration of the interventions and the radiation doses of CT fluoroscopy (CTF) guided biopsies of lung lesions with those of multislice CT (MS-CT) biopsy mode-guided biopsies. Methods: Data and images from 124 consecutive patients undergoing CTF-guided lung biopsy (group A) and 132 MS-CT-biopsy mode-guided lung biopsy (group B) were reviewed. CTF-guided biopsies were performed on a Siemens Emotion 6 CT scanner with intermittent or continuous CT-fluoroscopy, MS-CT biopsy mode-guided biopsies were performed on a Siemens Emotion 16 CT scanner. All biopsies were performed with a coaxial needle technique. Results: The two groups (A vs. B) did not differ significantly regarding sensitivity (95.5% vs. 95.9%), specificity (96.7% vs. 95.5%), negative predictive value (87.9% vs. 84%) or positive predictive value (98.8% vs. 98.9%). Pneumothorax was observed in 30.0% and 32.5% of the patients, respectively. Chest tube placement was necessary in 4% (group A) and 13% (group B) of the patients. The duration of the intervention was significantly longer in group A (median 37 min vs. 32 min, p = 0.04). The mean CT dose index (CTDI) was 422 in group A and 36.3 in group B (p < 0.001). Conclusion: Compared to CTF-guided biopsies, chest biopsies using the MS-CT biopsy mode show dramatically lower CTDI levels. Although the diagnostic yield of the procedures do not differ significantly, biopsies using the MS-CT-biopsy mode have a three-fold higher rate of chest tube placement.

The usefulness of three-dimensional imaging with spiral CT in the evaluation of upper airway stenosis

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Jang, Won Ho; Yoon, Dae Young; Bae, Sang Hoon; Rho, Young Soo; Jung, Yin Gyo [Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

1996-01-01

To assess the usefulness of three-dimensional (3D) spiral CT imaging in patients with upper airway stenosis. We performed 3D spiral CT imagings in ten patients in whom upper airway stenosis was clinically suspected. Eight of these patients had upper airway stenosis caused by intubation or tracheostomy (n-6), tuberculosis (n=1), or extrinsic compression by a thyroid mass (n=1). Spiral CT scanning (30-second continuous exposure and 90-mm length) was performed with a table speed of 3mm/sec and a section thickness of 3mm. The selected starting point was the epiglottis. The resulting data were reformatted by multiplanar reformation (MPR) and shaded surface display (SSD) with peeling after reconstruction of 2mm interval. In the evaluation of location and extent of stenosis, we compared fidings of 3D imaging with those of baseline axial images (n=10), endoscopy (n=9) and operation (n=4). The locations of stenosis in eight patients were as follows;tracheostoma (n=4), subglottic region (n=3), and larynx (n=1). In all eight, 3D imaging demonstrated the location and extent of stenosis, which exactly correlated with endoscopic and operative findings. In one patient, however, another stenotic area in the tracheal bifurcation was not discovered because this lesion was not included in the field of CT scan. In two patients, the diagnosis on 3D images of no 'stenosis' was comfirmed by clinical findings or operation. No differences in diagnostic accuracy were noted between axial images, MPR, and SSD when evalvating the location and extent of stenosis; vertical extent was shown more easily by 3D imaging than by axial images, however. 3D imaging with spiral CT may be an useful adjunctive method in the evaluation of upper airway stenosis with variable causes.

The usefulness of three-dimensional imaging with spiral CT in the evaluation of upper airway stenosis

International Nuclear Information System (INIS)

Jang, Won Ho; Yoon, Dae Young; Bae, Sang Hoon; Rho, Young Soo; Jung, Yin Gyo

1996-01-01

To assess the usefulness of three-dimensional (3D) spiral CT imaging in patients with upper airway stenosis. We performed 3D spiral CT imagings in ten patients in whom upper airway stenosis was clinically suspected. Eight of these patients had upper airway stenosis caused by intubation or tracheostomy (n-6), tuberculosis (n=1), or extrinsic compression by a thyroid mass (n=1). Spiral CT scanning (30-second continuous exposure and 90-mm length) was performed with a table speed of 3mm/sec and a section thickness of 3mm. The selected starting point was the epiglottis. The resulting data were reformatted by multiplanar reformation (MPR) and shaded surface display (SSD) with peeling after reconstruction of 2mm interval. In the evaluation of location and extent of stenosis, we compared fidings of 3D imaging with those of baseline axial images (n=10), endoscopy (n=9) and operation (n=4). The locations of stenosis in eight patients were as follows;tracheostoma (n=4), subglottic region (n=3), and larynx (n=1). In all eight, 3D imaging demonstrated the location and extent of stenosis, which exactly correlated with endoscopic and operative findings. In one patient, however, another stenotic area in the tracheal bifurcation was not discovered because this lesion was not included in the field of CT scan. In two patients, the diagnosis on 3D images of no 'stenosis' was comfirmed by clinical findings or operation. No differences in diagnostic accuracy were noted between axial images, MPR, and SSD when evalvating the location and extent of stenosis; vertical extent was shown more easily by 3D imaging than by axial images, however. 3D imaging with spiral CT may be an useful adjunctive method in the evaluation of upper airway stenosis with variable causes

Cerebral av angiomas: 3-dimensional demonstration by spiral CT

International Nuclear Information System (INIS)

Rieger, J.; Hosten, N.; Neumann, K.; Lemke, A.J.; Langer, R.; Lanksch, W.R.; Pfeifer, K.J.; Felix, R.

1994-01-01

In 20 patients with known or suspected supratentorial arteriovenous malformations, an attempt was made to see how far CT angiography with 3-dimensional reconstructions is able to make a diagnosis and to differentiate the various components of the angioma. Spiral CT was performed following an intravenous bolus injection of 60-80 ml of iodine containing contrast medium. In all patients the diagnosis was confirmed by intra-arterial DSA of the vertebral vessels. In 13 patients, av malformations could be diagnosed following multiplanar 3-D reconstructions which agreed with the findings on DSA. The large supplying vessels, the nidus and the large draining veins could be defined with certainty. In 6 patients follow-up examination after embolisation was performed. The results could be demonstrated in three dimensions and the success of treatment could be documented unequivocally. CT angiography with 3-D reconstruction is able to supply important information in the majority of intracranial av malformations, both during initial investigation and following treatment. (orig.) [de

Spiral CT portography: correlation with different injection rate

International Nuclear Information System (INIS)

Wu Dong; Zhou Kangrong; Chen Zuwang; Chen Gang; Chen Jin; Chen Huiming

2000-01-01

Objective: To choose optimal injection rate in spiral CT portography(CTP) by comparing 3D CTP images using different injection rates. Methods: Thirty-seven patients were randomly divided into 2 groups (11 and 26 cases in each group). Single-level dynamic scan was completed at the first liver hilus, starting at 15s or 30s after initial contrast injection(2 ml/kg) with injection rate 1.5 ml/s (slow group) or 3.0 ml/s (rapid group). The continuous scan were repeated every 5s for 120s or 135s. ROI was used to measure the CT value of the portal vein and the liver parenchyma, respectively, and then the time-density curves were drawn. Spiral CT portography were performed at injection rate of 1.5 ml/s or 3.0 ml/s as the delay time designed described above, including 98 cases in rapid group and 12 cases in slow group. Both MPVR (multi-projection volume reconstruction) and MIP (maximum intensity projection) were employed for reconstruction. All images were ranked according to the grade of portal vein, the different CT value between the portal vein and the liver parenchyma, the edge's definition of blood vessel, the grade of hepatic vein and the display of IVC by 2 radiologists. Results: The maximum density difference in average between the portal vein and the liver parenchyma was 53.4 HU and 83.9 HU, respectively (t = 16.418, P < 0.001) in slow group and rapid one, and the mean reaching time was 80s and 60s, respectively (t = 13.394, P < 0.001). In slow injection group, the average score of MPVR image was 9.3, while it was 12.5 (t = 3.514, P < 0.01) in rapid injection group. Rapid group was better than slow one at the PV-L, the grade of the portal vein, and the edge's definition of blood vessel. Conclusion: Using rapid injection rate (3.0 ml/s), the maximum density difference between the portal vein and the liver parenchyma increases, and the mean reaching time shortens. The quality of 3D CTP image of rapid injection rate (3.0 ml/s) is superior to that of slow injection rate

Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

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Obenauer, S.; Alamo, L.; Herold, T.; Funke, M.; Kopka, L.; Grabbe, E. [Department of Radiology, Georg August-University Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen (Germany)

2002-08-01

Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. (orig.)

Detection and classification of focal liver lesions in patients with colorectal cancer: Retrospective comparison of diffusion-weighted MR imaging and multi-slice CT

International Nuclear Information System (INIS)

Eiber, Matthias; Fingerle, Alexander A.; Brügel, Melanie; Gaa, Jochen; Rummeny, Ernst J.; Holzapfel, Konstantin

2012-01-01

Objectives: To compare the diagnostic performance of diffusion-weighted MR imaging (DWI) with multi-slice CT (MS-CT) in the detection and classification of focal liver lesions in patients with colorectal cancer. Methods: In a retrospective study 68 patients who underwent DWI at 1.5 T (b-values of 50, 300 and 600 s/mm 2 ) and contrast-enhanced MS-CT were analysed by two radiologists blinded to the clinical results. Imaging results were correlated with intraoperative surgical and ultrasound findings (n = 24), imaging follow-up or PET (n = 44). Sensitivity of DWI and MS-CT in detection of focal liver lesions was compared on a per-lesion and a per-segment basis. Receiver operator-characteristic (ROC) curves to determine the diagnostic performance and the sensitivities of correctly identifying liver metastases on a segmental base were calculated. Results: For lesion detection, DWI was significantly superior to MS-CT both on a per-lesion (difference in sensitivities for reader 1 and 2 22.65% and 19.06%, p < 0.0001) and a per-segment basis (16.86% and 11.76%, p < 0.0001). Especially lesions smaller than 10 mm were better detected with DWI compared to MS-CT (difference 41.10% and 29.45%, p < 0.0001). ROC-analysis showed superiority for lesions classification (p < 0.0001) of DWI (AUC: 0.949 and 0.951) as compared to MS-CT (AUC: 0.879 and 0.892, p < 0.0001 and p = 0.005). DWI was able to filter out metastatic segments with a higher sensitivity (88.2 and 86.5%) compared to MS-CT (68.0 and 67.4%, p < 0.0001 and p = 0.005, respectively). Conclusion: Compared to MS-CT DWI is both more sensitive in the detection of liver lesions and more accurate in determining the extent of metastatic disease in patients with colorectal cancer and therefore might help to optimize therapeutic management in those patients.

Spiral CT arthrography of the knee: technique and value in the assessment of internal derangement of the knee

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Berg, Vande B.C.; Lecouvet, F.E.; Maldague, B.; Malghem, J. [Department of Radiology, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium); Poilvache, P. [Department of Orthopedic Surgery, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium)

2002-07-01

Computed tomography imaging has achieved excellent multiplanar capability and submillimeter spatial resolution due to the development of the spiral acquisition mode and multidetector row technology. Multidetector spiral CT arthrography (CTA) yields valuable information for the assessment of internal derangement of the joints. This article focuses on the value of spiral CTA of the knee in the assessment of the meniscus, anterior cruciate ligament, and hyaline cartilage lesions. Advantages and disadvantages of spiral CTA with respect to MR imaging are presented. (orig.)

Diagnosis of pelvic wall tumor on multislice CT

International Nuclear Information System (INIS)

Zhang Keyun; Deng Lequn; Lei Hongwei

2011-01-01

Objective: To evaluate the value of multi-slice CT (MSCT) in diagnosing pelvic wall tumors. Methods: MSCT of 21 cases of pelvic wall tumors including metastasis (10), neurogenic tumor (5), chondrosarcoma (2), chordoma (1), aneurysmal bone cyst (1), giant cell tumor (1), and osteochondroma (1) was retrospectively analyzed. Results: CT appearances of pelvic wall tumors include bony destruction and soft tissue masses. Common features were bone destruction in metastasis, expansion of the neuroforamen in neurogenic tumor, pleomorphic calcification in chondrosarcoma, lower sacral vertebral location of chordoma, iliac crest bone destruction in giant cell tumor, cauliflower-like nodules in osteochondroma. Conclusion: MSCT with three-dimensional volume rendering demonstrates well the tumor shape, size, extent, internal structure and relationship with the surrounding organs to aid diagnosis of pelvic wall tumors. (authors)

Quantitative evaluation in enhancement of pancreas and adjacent vessels during spiral CT

International Nuclear Information System (INIS)

Kim, Hyoung Seuk; Shin, Kue Hee; Park, Cheol Min; Cha, Sang Hoon; Chung, Kyoo Byung

1997-01-01

To determine by quantitative evaluation of pancreatic and adjacent vascular enhancement during spiral CT, the ideal scan delay for examination of the pancreas. Dual(n=3D90) and triple(n=3D90) phase spiral CT scans of patients whose pancreas showed no pathologic condition were retrospectively evaluated. Dual-phase scans were performed at 43 seconds(early), and 5-6 minutes(delayed) after the injection of 120ml of contrast material at an injection rate of 3ml/sec;triple-phase scans were performed at 25 seconds(arterial),60-65 seconds (portal) and 5-6 minutes (delayed) after the injection of 120-140ml of contrast material at an injection rate of 2-4ml/sec, and ten patients also underwent precontrast scanning. CT attenuation values(HU) were measured in the head, body and tail of the pancreas, aorta, and main portal vein during each phase of all scans. Triple-phase protocol was used to measure the effect of different total volumes and injection rates on enhancement of the pancreas and adjacent vessels. There was no significant difference in the degree of enhancement of the pancreas head, body and tail during each phase(p>0.05). The pancreas was maximally enhanced on 43 second delayed scan(132±20HU)(p 0.05). The main portal vein showed maximum enhancement on 43-second delayed scan(207±44HU)(p<0.05). Different total volume of contrast material did not change the enhancement of the pancreas and adjacent vessels. At an injection rate of 2ml/sec, peak enhancement of the pancreas, aorta and portal vein was obtained on 60-65 second delayed scan, and at 4ml/sec, peak enhancement was obtained on 25 second delayed scan(p<0.05). Observing the usual protocols for abdominal spiral CT scanning, the pancreas was most effectively evaluated using a 43-second delayed scan. An increased injection rate resulted in earlier enhancement of the pancreas, aorta and portal vein

Experimental study of multi-slice CT for the evaluation of atherosclerotic plaques

International Nuclear Information System (INIS)

Tang Xiang; Lv Bin; Wu Wenhui; Lu Jinguo; Dai Ruping; Bai Hua; Tang Yue; Lv Fengying; Jiang Shiliang

2009-01-01

Objective: To evaluate the diagnostic values of MSCT for detecting atherosclerotic plaques on New Zealand rabbits models in comparison with pathologic results. Methods: Fifteen New Zealand rabbits were enrolled in this study, including 5 with balloon injury and high-fat diet (group A), 5 with high-fat diet only (group B) and 5 with regular feed (group C). 16th week late, contrast-enhanced MSCT scan was performed in all rabbits with 16 slice MSCT (16-MSCT) in group A and 64 slice MSCT (64-MSCT) in group B and C. The CT and pathological findings were compared in a double-blind manner. The sensitivities and specificities of 16-MSCT and 64-MSCT for detecting atherosclerotic plaques were evaluated by using Fisher test and χ 2 test. Results: Sixty and seventy-five images on 16-MSCT and 64-MSCT had corresponding pathological slices. The sensitivities for the detection of plaques on 16-MSCT and 64-MSCT were 41.5% (22/53) and 64.9% (24/37), and specificities of 85.7% (6/7) and 89.5% (34/38), respectively. Conclusions: 64-MSCT has a higher sensitivity in the detection of atherosclerotic plaques than 16-MSCT. Both scanners can be used to preclude the diagnosis of atherosclerosis. (authors)

MR appearance of cartilage defects of the knee: preliminary results of a spiral CT arthrography-guided analysis

International Nuclear Information System (INIS)

Berg, B.C. vande; Lecouvet, F.E.; Maldague, B.; Malghem, J.

2004-01-01

The aim of this study was to determine signal intensity patterns of cartilage defects at MR imaging. The MR imaging (3-mm-thick fat-suppressed intermediate-weighted fast spin-echo images) was obtained in 31 knees (21 male and 10 female patients; mean age 45.5 years) blindly selected from a series of 252 consecutive knees investigated by dual-detector spiral CT arthrography. Two radiologists determined in consensus the MR signal intensity of the cartilage areas where cartilage defects had been demonstrated on the corresponding reformatted CT arthrographic images. There were 83 cartilage defects at spiral CT arthrography. In 52 (63%) lesion areas, the MR signal intensity was higher than that of adjacent normal cartilage with signal intensity equivalent to (n=31) or lower than (n=21) that of articular fluid. The MR signal intensity was equivalent to that of adjacent normal cartilage in 17 (20%) lesion areas and lower than that of adjacent cartilage in 8 (10%) lesion areas. In 6 (7%) lesion areas, mixed low and high signal intensity was observed. The MR signal intensity of cartilage defects demonstrated on spiral CT arthrographic images varies from low to high on fat-suppressed intermediate-weighted fast spin-echo MR images obtained with our equipment and MR parameters. (orig.)

Noninvasive diagnosis of suspected severe pulmonary embolism. Trans-esophageal echocardiography vs spiral CT

International Nuclear Information System (INIS)

Pruszczyk, P.; Torbicki, A.; Pacho, R.

1998-01-01

Patients with pulmonary embolism (PE) and echocardiographic signs of right ventricular over-lead have worse prognosis and may be require aggressive therapy. Unequivocal confirmation of PE is required before thrombolysis or embolectomy. This study compares the value of trans-esophageal echocardiography (TEE) and spiral CT (sCT) in direct visualization of pulmonary artery thrombo-emboli in patients with suspected PE and echocardiographic signs of right ventricular over-lead. Because of high prevalence of bilateral central pulmonary thrombo-emboli in patients with hemo-dynamically significant PE, both sCT and TEE allow its definitive confirmation in most cases. Thrombi reported by sCT distally to lobar arteries should be interpreted with caution. (author)

SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

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Roemer, W.; Kuwert, T. [Nuklearmedizinische Klinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Beckmann, M.W. [Frauenklinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Forst, R. [Lehrstuhl fuer Orthopaedie mit Orthopaedischer Chirurgie, Friedrich-Alexander Univ. Erlangen/Nuernberg (Germany); Bautz, W. [Radiologisches Inst., Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany)

2005-07-01

In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

International Nuclear Information System (INIS)

Roemer, W.; Kuwert, T.; Beckmann, M.W.; Forst, R.; Bautz, W.

2005-01-01

In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

Pancreatic neuroendocrine tumours: correlation between MSCT features and pathological classification

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Luo, Yanji; Dong, Zhi; Li, Zi-Ping; Feng, Shi-Ting [The First Affiliated Hospital, Sun Yat-Sen University, Department of Radiology, Guangzhou, Guangdong (China); Chen, Jie [The First Affiliated Hospital, Sun Yat-Sen University, Department of Gastroenterology, Guangzhou, Guangdong (China); Chan, Tao; Chen, Minhu [Union Hospital, Hong Kong, Medical Imaging Department, Shatin, N.T. (China); Lin, Yuan [The First Affiliated Hospital, Sun Yat-Sen University, Department of Pathology, Guangzhou, Guangdong (China)

2014-11-15

We aimed to evaluate the multi-slice computed tomography (MSCT) features of pancreatic neuroendocrine neoplasms (P-NENs) and analyse the correlation between the MSCT features and pathological classification of P-NENs. Forty-one patients, preoperatively investigated by MSCT and subsequently operated on with a histological diagnosis of P-NENs, were included. Various MSCT features of the primary tumour, lymph node, and distant metastasis were analysed. The relationship between MSCT features and pathologic classification of P-NENs was analysed with univariate and multivariate models. Contrast-enhanced images showed significant differences among the three grades of tumours in the absolute enhancement (P = 0.013) and relative enhancement (P = 0.025) at the arterial phase. Univariate analysis revealed statistically significant differences among the tumours of different grades (based on World Health Organization [WHO] 2010 classification) in tumour size (P = 0.001), tumour contour (P < 0.001), cystic necrosis (P = 0.001), tumour boundary (P = 0.003), dilatation of the main pancreatic duct (P = 0.001), peripancreatic tissue or vascular invasion (P < 0.001), lymphadenopathy (P = 0.011), and distant metastasis (P = 0.012). Multivariate analysis suggested that only peripancreatic tissue or vascular invasion (HR 3.934, 95 % CI, 0.426-7.442, P = 0.028) was significantly associated with WHO 2010 pathological classification. MSCT is helpful in evaluating the pathological classification of P-NENs. (orig.)

Effect of the degree of sternal depression on the cardiac rotation in pectus excavatum: evaluation with spiral CT

International Nuclear Information System (INIS)

Yu Jianqun; Yang Zhigang; Li Zhenlin; Guo Yingkun; Lu Chunyan; Zhang Mei

2004-01-01

Objective: To evaluate the effects of the degree of sternal depression on the cardiac rotation in pectus excavatum by using spiral CT. Methods: Spiral CT features of 32 patients with surgically corrected pectus excavatum were retrospectively reviewed. They included 27 males and 5 females ranging in age from 6 months to 17 years (mean, 6.3 years). Analysis was based on relationship among the degree of sternal depression, CT depression index, cardiac rotation angle, and PV angle. Results: 32 cases of pectus excavatum presented the sternal depression (21 ± 7) mm, CT depression index 2.9 ± 1.8, cardiac rotation angle (55.9 ± 9.8) degree, and PV angle (49.8 ± 14.0) degree, respectively. The sternal depression (17 mm) in cases with CT depression index less than 2.4 was smaller than those with CT depression index 2.4-2.9 (21 mm) and CT depression index larger than 2.9 (27 mm) (F 5.39, P<0.01). Cardiac rotation angle (49.7 degree) in cases with CT depression index less than 2.4 was smaller than those with CT depression index 2.4-2.9 (55.5 degree) and CT depression index larger than 2.9 (66.9 degree) (F=7.44, P<0.01). PV angle (58.7 degree) in cases with CT depression index less than 2.4 was larger than those with CT depression index 2.4-2.9 (46.5 degree) and CT depression index more than 2.9 (42.4 degree) ( F=3.33, P<0.05). Cardiac rotation angle of pectus excavatum had positive correlation with the CT depression index (γ=0.73, P<0.01). Conclusion: Spiral CT is a better tool for revealing chest deformity and corresponding cardiac rotation. The degree of sternal depression in pectus excavatum directly influences the cardiac rotation, and they had positive correlation. (authors)

Clinical value of 64-slice spiral CT for classification of femoral neck fracture

International Nuclear Information System (INIS)

Zhu Jiangtao; Gong Jianping; Cai Wu; Zhu Jianbing; Chen Guangqiang; Qian Minghui

2011-01-01

Objective: To evaluate the clinical application of 64-slice spiral CT for classification of femoral neck fracture. Methods: The survey was comprised of 46 patients with femoral neck fractures detected with plain radiographs and CT images. Cases were randomly presented in 2 formats: plain radiographs and CT. Garden classification was queried. Modification of garden classification (nondisplaced vs displaced) was taken to compare with plain radiographs and CT in the study. Results: The results of classification for plain radiographs were 2 cases of Garden Ⅰ, 10 cases of Ⅱ, 22 cases of Ⅲ, and 12 cases of Ⅳ. Those for CT were 1 cases of Garden Ⅰ, 4 cases of Ⅱ, 26 cases of Ⅲ, and 15 cases of Ⅳ. CT improved the accuracy of Garden Classification (P<0.05). Conclusion: Garden classification using CT images shows good conformation with results of surgery. 64-Slic CT is better plain radiographs for Garden classification of femoral neck fracture. (authors)

Association between the mean CT value on a scout view and the dependent mA selection method in coronary artery imaging on 64-row multi-slice spiral CT

International Nuclear Information System (INIS)

Gao Jianhua; Li Tao; Mi Fengtang; Li Na; Cui Ying; Dai Ruping; Li Jianying

2009-01-01

Objective: To characterize the association between the mean CT value on a scout view and the dependent mA selection method, and to evaluate the clinical value of a mA selection method based on scout view mean CT value in obtaining individualized scan protocol and consistent image quality for patient population on 64-row MSCT CT coronary angiography (CTCA). Methods: One hundred patients (group A) underwent CTCA consecutively using standard protocol with a fixed mA. The mean CT value of a fixed ROI (region of interest) from the scout AP view and the CTCA image noise (standard deviation on the root of ascending aorta) were measured. The correlation between CT values and noise was studied to establish a formula and a list to determine the required mA for obtaining a consistent CTCA image noise based on the measured SV CT value. Another 100 patients (group B) were scanned using the same parameters as group A except the mA and the CT value was also measured. The mA was determined by the list established previously. The CTCA image quality (IQ) as well as the image noise (IN) and the effective dose (ED) from the two groups were statistically analyzed using t-test. The CT findings for the 32 patients in the group B were also compared with the selective coronary angiography (SCA) results. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CTCA for detection of significant stenosis were obtained. Results: The formula between the required mA and the CT value was: XmA=FmA x [(K 1 x CTscout + C 1 )/INa] 2 . The CTCA images in B group had statistically higher IN (27.66±2.57, 22.22±4.17, t=11.33, P=0.000), but no statistical difference between IQ scores for the two groups (3.29±0.66, 3.37±0.67, t=0.009, P=0.990), and ED [(8.72±2.51) versus (12.53±0.90) mSv] was 30% lower for the B group (P<0.01). For the 32 patients in the B group who had SCA, the CTCA sensitivity, specificity, positive predictive value, negative

The 64-MSCT study of relationship between renal corticomedullary differentiation, contrast between renal cortex and medulla, renal cortex and medulla CT peak value with the single renal function in hydronephrotic kidney

International Nuclear Information System (INIS)

Wang Yunhua; Hou Weiwei; Liu Ruihong; He Jianjun; Zhi Ke

2009-01-01

Objective: To study 64-MSCT perfusion imaging features about renal corticomedullary differentiation, contrast between renal cortex and medulla (CMC), renal cortex and medulla CT peak value in normal and hydronephrotic kidneys, and to explore the relationship between them and the unilateral renal function. Methods: Thirty-six patients with obstructive nephrohydrosis underwent 64-MSCT perfusion scanning. The split renal glomerular filtration rates (GFR) of their kidneys were measured by SPECT renal dynamic imaging. The 72 kidneys were divided into groups of normal renal function group, mild and severe renal impairment groups according to GFR. Renal corticomedullary differentiation on CT images was graded as clear, obscure, part clear. The CT intensity of cortex and medulla was measured in order to calculate contrast between renal cortex and medulla (CMC). Using Pearson correlation test, the correlation between them and renal GFR were examined. Results: (1) In the 24 kidneys of normal group, all kidneys showed clear CMD. In the 21 kidneys of mild renal impairment group, 14 kidneys showed clear CMD, 2 showed obscure CMD and 5 showed part clear of CMD. In the 27 kidneys of severe renal impairment group, 7 kidneys showed clear CMD, 5 showed obscure CMD and 15 showed part clear of CMD. (2)The CMC of normal group was 0.62 ± 0.20, while it was 0.52 ± 0.14 and 0.37 ± 0.11 for mild renal impairment group and severe renal impairment group CMC respectively. The CMC had positive linear correlation with GFR (r=0.536,P<0.05). (3) The renal cortex and medulla CT peak value of normal group were (133 ± 22) and (104 ± 16) HU; The renal cortex and medulla CT peak value of mild renal impairment group were (91 ± 29) and (76 ± 25) HU; The renal cortex and medulla CT peak value of severe renal impairment group were (68 ± 24) and (57 ± 21) HU(F=42.76 and 32.68,P<0.05). The renal cortex and medulla CT peak value had positive linear correlation with GFR (r=0.672 and 0.623, P<0

A backprojection-filtration algorithm for nonstandard spiral cone-beam CT with an n-PI-window

International Nuclear Information System (INIS)

Yu Hengyong; Ye Yangbo; Zhao Shiying; Wang Ge

2005-01-01

For applications in bolus-chasing computed tomography (CT) angiography and electron-beam micro-CT, the backprojection-filtration (BPF) formula developed by Zou and Pan was recently generalized by Ye et al to reconstruct images from cone-beam data collected along a rather flexible scanning locus, including a nonstandard spiral. A major implication of the generalized BPF formula is that it can be applied for n-PI-window-based reconstruction in the nonstandard spiral scanning case. In this paper, we design an n-PI-window-based BPF algorithm, and report the numerical simulation results with the 3D Shepp-Logan phantom and Defrise disk phantom. The proposed BPF algorithm consists of three steps: cone-beam data differentiation, weighted backprojection and inverse Hilbert filtration. Our simulated results demonstrate the feasibility and merits of the proposed algorithm

Study of liver volume measurement and its clinical application for liver transplantation using multiple-slice spiral CT

International Nuclear Information System (INIS)

Peng Zhiyi; Yu Zhefeng; Kuang Pingding; Xiao Shengxiang; Huang Dongsheng; Zheng Shusen; Wu Jian

2004-01-01

Objective: To study the accuracy of liver volume measurement using MSCT and its application in liver transplantation. Methods: (1) Experimental study. Ten pig livers were scanned using MSCT with two collimations (3.2 mm and 6.5 mm) and pitch 1.25. Semi-automatic method was used to reconstruct 3D liver models to measure the liver volume. (2) Clinical study. Twenty-three patients received MSCT scan with collimation of 6.5 mm before liver transplantation. Same method was used to calculate the liver volume and the measurement was repeated by the same observer after 1 month. Results: (1) Experimental study. Actual liver volumes were (1134.1 ± 288.0) ml. Liver volumes by MSCT with two collimations were (1125.0 ± 282.5) ml (3.2 mm) and (1101.6 ± 277.6) ml (6.5 mm). The accuracy was (99.5 ± 0.8)% and (97.4 ± 0.8)%, respectively. Both showed same good agreement with actual liver volume: r=0.999, P<0.01 (2) Clinical study. Actual liver volumes were (1455.7±730.0) ml. Liver volume by MSCT was (1462.7 ± 774.1) ml. The accuracy was (99.5±9.6)%, r=0.986, P<0.01. Liver volume measured again was (1449.4 ± 768.9) ml, r=0.991 (P<0.01). Conclusion: MSCT can assess the liver volume correctly, and could be used as a routine step for evaluations before liver transplantation

Comparison of endoscopic ultrasonography and multislice spiral computed tomography for the preoperative staging of gastric cancer - results of a single institution study of 610 Chinese patients.

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Xing-Yu Feng

Full Text Available BACKGROUND: This study compared the performance of endoscopic ultrasonography (EUS and multislice spiral computed tomography (MSCT in the preoperative staging of gastric cancer. METHODOLOGY/PRINCIPAL FINDINGS: A total of 610 patients participated in this study, all of whom had undergone surgical resection, had confirmed gastric cancer and were evaluated with EUS and MSCT. Tumor staging was evaluated using the Tumor-Node-Metastasis (TNM staging and Japanese classification. The results from the imaging modalities were compared with the postoperative histopathological outcomes. The overall accuracies of EUS and MSCT for the T staging category were 76.7% and 78.2% (P=0.537, respectively. Stratified analysis revealed that the accuracy of EUS for T1 and T2 staging was significantly higher than that of MSCT (P<0.001 for both and that the accuracy of MSCT in T3 and T4 staging was significantly higher than that of EUS (P<0.001 and 0.037, respectively. The overall accuracy of MSCT was 67.2% when using the 13th edition Japanese classification, and this percentage was significantly higher than the accuracy of EUS (49.3% and MSCT (44.6% when using the 6th edition UICC classification (P<0.001 for both values. CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that the overall accuracies of EUS and MSCT for preoperative staging were not significantly different. We suggest that a combination of EUS and MSCT is required for preoperative evaluation of TNM staging.

Spiral CT features of abdomen after whipple's operation

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Kim, T. H.; Lee, K. Y.; Shin, K. H.; Jung, M. H.; Park, C. M.; Cha, I. H. [Korea Univ. College of Medicine, Seoul (Korea, Republic of)

1997-04-01

To assess the CT features of postoperative anatomical changes, surgical complications, and patterns of tumor recurrence after Whipple's operation. 42 spiral CT scans of 31 patients who had undergone Whipple's operation were retrospectively reviewed. Postoperative diagnoses were distal CBD cancer in 13 patients, cancer of the ampulla of Vater in ten, cancer of the head of the pancreas in seven, and microcystic cystadenocarcinoma of the pancreas in one. Time intervals between surgery and CT ranged from 1 week to 5 years. CT features of postoperative anastomotic changes, surgical complications, and patterns of tumor recurrence were analyzed. Gastro- or duodeno-jejunal anastomosis was seen in 32 CT scans(74%), pancreaticojejunostomy in 27(64%), and choledochojejunostomy in 24(57%). Pneumobilia was seen in ten patients(34%). Abnormal fluid collections in the peripancreatic and perihepatic space were demonstrated in two patients who underwent CT scans within 3 weeks after operation. Other complications included wound abscess(n=2), and portal vein occlusion(n=1). The most common site of metastasis was the lymph node(n=8)(retroperitoneal:n=5; mesentery root:n=4; and celiac:n=2), followed by the liver(n=6), peritoneum(n=3), adrenal gland(n=2), and afferent loop(n=1). In three cases, there was local recurrence in the pancreatic bed. To reduce possible diagnostic errors during CT interpretation, a Knowledge of normal postoperative anatomy, common complications, and patterns of disease recurrence following Whipple's operation is important.

Recurrent pyogenic cholangitis: clinico-pathologic correlation of focal attenuation differences on multi-phasic spiral CT

International Nuclear Information System (INIS)

Jeong, Jun Yong; Han, Joon Koo; Kim, Tae Kyoung; Kim, Seog Joon; Kim, Hyun Bum; Choi, Byung Ihn

2002-01-01

To determine the clinical and the pathologic significance of the focal attenuation differences (FAD) and bile duct wall enhancement occurring in recurrent pyogenic cholangitis (RPC) and seen at multiphasic spiral CT. Among the multiphasic (non-contrast, arterial and portal or delayed phase) spiral CT findings of 60 consecutive patients, two types of FAD were noted during the non-contrast phase. These were Type A (iso) and Type B (low attenuation), and their distribution pattern (lobar versus patchy, multifocal) and the and the presence or absence of bile duct wall enhancement were recorded. The radiologic findings were correlated with the clinical and pathologic findings. Two types of FAD were noted in 40 of the 60 patients. Active in flammation was present in 19 of the 27 with Type-A and in ten of the 15 in whom the presence of RPC was pathologically proven. Ten of the 13 with Type-B FAD were in a subclinical state, and nine of the ten in whom RPC was pathologically proven had chronic inflammation. Among 20 patients who did not have FAD, RPC was subclinical in 18 and dormant in nine of the eleven in whom its presence was pathologically proven (p<0.001). Clinico-pathologic correlation with bile duct wall enhancement and the distribution pattern of FAD showed no statistical significance. The inflammatory activity of RPC can be predicted by analysis of the FAD seen at multiphasic spiral CT

Multiple-slice spiral CT evaluation of occipital condyle fractures

International Nuclear Information System (INIS)

Wang Xifu; Zhang Guixiang; Li Kang'an; Zhao Jinglong; Wang Han; Feng Yan; Zheng Linfeng

2011-01-01

Objective: To explore the MSCT findings of occipital condyle fracture (OCF) and improve its diagnostic accuracy. Methods: Nineteen patients with OCF, selected from 110 patients suffering high energy injuries at the craniocervical junction, were enrolled into the study. The MSCT appearances of OCFs were retrospectively analyzed by two experienced radiologists. OCF had four types: type Ⅰ was a comminuted fracture, type Ⅱ was a extension of basilar skull fracture, type Ⅲ was an avulsion fracture at the attachment site of alar ligament on occipital condyle, type Ⅳ was a fracture of mixed pattern consisting of two or more above fracture types. Results: In 19 patients, the left, right and bilateral OCFs were seen in 7, 11 cases, and 1 case, respectively. Type Ⅰ was found in one case, which was a comminution of the left occipital condyle. Type Ⅱ was found in 5 cases, which involved the middle and posterior parts of occipital condyles with 2 on the left and 3 on the right, Type Ⅲ was found in 12 cases which showed various degree of fragment displacement with 3 occurring on the left, 8 on the right, 1 involving bilateral sides, 6 involving articular surfaces and 7 accompanying by enlargement of alar ligaments. Type Ⅳ was found in one case, with coexistence of Type Ⅱ and type Ⅲ In addition, OCFs were accompanied by head and (or) cervical spine injuries in 14 cases, which included cranial fracture in 8 cases, epidural hematoma in 4 cases, subarachnoid hemorrhage in one case, cerebral contusion and laceration in one case, subfalcial hernia in one case, cervical spine fracture and dislocation in 9 cases, and so on. Conclusion: OCFs can be accurately diagnosed by MSCT, which is important for selection of treatment protocols. (authors)

Automatic detection of pulmonary nodules at spiral CT: clinical application of a computer-aided diagnosis system

International Nuclear Information System (INIS)

Wormanns, Dag; Fiebich, Martin; Saidi, Mustafa; Diederich, Stefan; Heindel, Walter

2002-01-01

The aim of this study was to evaluate a computer-aided diagnosis (CAD) workstation with automatic detection of pulmonary nodules at low-dose spiral CT in a clinical setting for early detection of lung cancer. Eighty-eight consecutive spiral-CT examinations were reported by two radiologists in consensus. All examinations were reviewed using a CAD workstation with a self-developed algorithm for automatic detection of pulmonary nodules. The algorithm is designed to detect nodules with diameters of at least 5 mm. A total of 153 nodules were detected with at least one modality (radiologists in consensus, CAD, 85 nodules with diameter <5 mm, 68 with diameter ≥5 mm). The results of automatic nodule detection were compared to nodules detected with any modality as gold standard. Computer-aided diagnosis correctly identified 26 of 59 (38%) nodules with diameters ≥5 mm detected by visual assessment by the radiologists; of these, CAD detected 44% (24 of 54) nodules without pleural contact. In addition, 12 nodules ≥5 mm were detected which were not mentioned in the radiologist's report but represented real nodules. Sensitivity for detection of nodules ≥5 mm was 85% (58 of 68) for radiologists and 38% (26 of 68) for CAD. There were 5.8±3.6 false-positive results of CAD per CT study. Computer-aided diagnosis improves detection of pulmonary nodules at spiral CT and is a valuable second opinion in a clinical setting for lung cancer screening despite of its still limited sensitivity. (orig.)

Skeletal and total body volumes of human fetuses: assessment of reference data by spiral CT

International Nuclear Information System (INIS)

Braillon, Pierre M.; Buenerd, Annie; Bouvier, Raymonde; Lapillonne, Alexandre

2002-01-01

Objective: To define reference data for skeletal and total body volumes of normal human fetuses. Materials and methods: Spiral CT was used to assess the skeletal and total body volumes of 31 normal human stillborn infants with gestational age (GA) and body weight (BW) ranging from 14 to 41.5 weeks and 22 to 3,760 g, respectively. CT scans (slice thickness 2.7 mm, pitch 0.7) were performed within the first 24 h after delivery. Precise bone and soft-tissue windows were defined from analysis of the density along the diaphysis of the fetal long bones and from the measurement of a phantom that mimics soft tissues. Lengths and volumes were obtained from 3D reconstructions. The femur lengths measured from CT images (FLct) were compared with those provided by US studies (FLus). Results: Significant correlations (r>0.9) were found between BW, measured volumes of the entire skeleton or head, long-bone lengths, biparietal diameter and GA. Strong linear correlations (r>0.98) were observed between FLct and FLus. Conclusions: Skeletal and total body volume values obtained using spiral CT were significantly correlated with fetal biometric measurements. These data could complement those obtained in obstetric investigations with US. (orig.)

Preliminary application of 320-detector spiral CT with ECG editing for assessing coronary artery in-stent restenosis

International Nuclear Information System (INIS)

Li Zhiming; Tan Lilian; Li Shuxin; Fu Xi; He Weihong; Liu Ke; Huang Yong; Yu Lin

2011-01-01

Objective: To determine the value of 320-detector spiral CT with retrospective ECG gating and editing software for detecting coronary artery in-stent restenosis. Methods: CT scans of 14 patients with coronary artery stnets were retrospectively analyzed. The examinations were performed using a 320-detector spiral CT scanner and retrospective ECG gating combined with ECG editing software. The image quality of reconstructed coronary artery in-stents was compared before and after the editing of synchronously recorded ECG. The paired-sample t test was used for statistical analysis. Results: Before ECG editing, arrhythmia and in-stent artifact resulted in image blurring, missing arterial segments, significant stepladder artifacts or non-visualization of the interior of stents. Of 14 cases before ECG editing, in-stent restenosis was detected in 10 and patency in 3. The coronary artery stent and distal bifurcation were delineated in one patient. After ECG editing, the image quality of coronary artery stents was improved with detection of in-stent restenosis (4 cases) including the one case that not evaluable before ECG editing. The average image quality score before ECG editing (2.14±0.86) was significantly (P<0.001) lower than that after ECG editing (3.07±0.73). Conclusion: Retrospective ECG gating combined with ECG editing of 320-detector spiral CT can reduce the artifacts produced by arrhythmia or in-stent swings and improve the imaging quality of coronary artery stents. (authors)

Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT

NARCIS (Netherlands)

Parsa, A.; Ibrahim, N.; Hassan, B.; van der Stelt, P.; Wismeijer, D.

2015-01-01

Objectives The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the

Helical CT defecography; La defecografia con Tomografia Computerizzata spirale

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Ferrando, R.; Fiorini, G.; Beghello, A.; Cicio, G.R.; Derchi, L.E.; Consigliere, M.; Resasco, M. [Genua Univ., Genua (Italy). Ist. di Radiologia, Cattedra R; Tornago, S. [Genua Univ. Genua (Italy). 2 Clinica Ortopedica

1999-11-01

The purpose of this work is to investigate the possible role of Helical CT defecography in pelvic floor disorders by comparing the results of the investigations with those of conventional defecography. The series analyzed consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with Helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; it is used a remote-control unit. The parameters for Helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 m As and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. Coronal Helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, Helical CT defecography performed well in study of pelvic floor disorders and can follow conventional defecography especially in questionable cases. [Italian] Scopo di questo lavoro e' ricercare un ruolo per la defeco-TC con apparecchiatura elicoidale nello studio delle malattie del pavimento pelvico confrontandola con i risultati consolidati della defecografia tradizionale. Si sono visionati 90 pazienti, 62 femmine e 28 maschi, con eta' compresa tra 24 e 82 anni, con defecografia tradizionale; di questi, 18 casi con diagnosi dubbia sono stati studiati anche con defeco-TC spirale

Assessment of colonic disease by multi-slice CT pneumocolon after incomplete colonoscopy

International Nuclear Information System (INIS)

Zhao Zehua; Liu Wenjin; Xu Songsen; Wang Kang; Wang Weizhong

2004-01-01

Objective: To evaluate the use of preoperative MSCT in patients with clinically suspected colorectal disease after incomplete colonoscopy. Methods: After incomplete colonoscopy, 31 patients underwent MSCT before and after intravenous injection of iodinated contrast agent. CT virtual colonography (CTVC), multiplanar reformation (MPR), shaded surface display (SSD), and Raysum images were obtained by using 4 different software in workstation. The results of MSCT were compared with the findings of colonoscopy, intraoperative colon palpation, and postoperative pathology. Results: After incomplete colonoscopy, MSCT was successfully performed in all 31 cases. Postoperative pathology revealed 22 colorectal cancers (one synchronous cancers, two with polyps) and 9 benign disease. 22 colonic carcinomas were all correctly diagnosed by MSCT (including synchronous disease), 2 benign diseases were misdiagnosed as malignancy, and one polyp was missed. Conclusion: MSCT is a feasible and useful method for evaluating the entire colon before surgery in patients with occlusive disease. (author)

Assessment of calcium scoring performance in cardiac computed tomography

International Nuclear Information System (INIS)

Ulzheimer, Stefan; Kalender, Willi A.

2003-01-01

Electron beam tomography (EBT) has been used for cardiac diagnosis and the quantitative assessment of coronary calcium since the late 1980s. The introduction of mechanical multi-slice spiral CT (MSCT) scanners with shorter rotation times opened new possibilities of cardiac imaging with conventional CT scanners. The purpose of this work was to qualitatively and quantitatively evaluate the performance for EBT and MSCT for the task of coronary artery calcium imaging as a function of acquisition protocol, heart rate, spiral reconstruction algorithm (where applicable) and calcium scoring method. A cardiac CT semi-anthropomorphic phantom was designed and manufactured for the investigation of all relevant image quality parameters in cardiac CT. This phantom includes various test objects, some of which can be moved within the anthropomorphic phantom in a manner that mimics realistic heart motion. These tools were used to qualitatively and quantitatively demonstrate the accuracy of coronary calcium imaging using typical protocols for an electron beam (Evolution C-150XP, Imatron, South San Francisco, Calif.) and a 0.5-s four-slice spiral CT scanner (Sensation 4, Siemens, Erlangen, Germany). A special focus was put on the method of quantifying coronary calcium, and three scoring systems were evaluated (Agatston, volume, and mass scoring). Good reproducibility in coronary calcium scoring is always the result of a combination of high temporal and spatial resolution; consequently, thin-slice protocols in combination with retrospective gating on MSCT scanners yielded the best results. The Agatston score was found to be the least reproducible scoring method. The hydroxyapatite mass, being better reproducible and comparable on different scanners and being a physical quantitative measure, appears to be the method of choice for future clinical studies. The hydroxyapatite mass is highly correlated to the Agatston score. The introduced phantoms can be used to quantitatively assess the

Measurement of modulation transfer function in z-axis for multi-slice spiral CT using the micro-disk method. Comparison with the bead method and examination of geometric influence

International Nuclear Information System (INIS)

Hara, Takanori

2003-01-01

Many methods of measuring the section-sensitive profile (SSP) of computed tomography (CT) by the input of a delta function have been reported. In Japan, the bead method is used as a common measurement because of the high flexibility of the multi-purpose method. However, the intensity of the response of the bead method tends to decline, creating a relatively large error in the base of SSPs. A problem is considered to be the accuracy of measurement in evaluating spatial resolution along the z-axis in multi-slice spiral/helical CT (MSCT). We therefore evaluated the modulation transfer function (MTF) by conducting research with the micro-disk method (100 μm thickness and 1.0 mmφ diameter) and the bead method (1.0 mmφ diameter) for the same input width. Moreover, in the micro-disk method, we also examined alignment, circular region of interest (ROI), and the energy characteristic. Our comparison of MTFs obtained by the micro-disk method and the bead method showed that the former resulted in a higher value and lower standard deviation. The difference was significant at p<0.01. Measurement using the micro-disk method did not show significant differences in terms of alignment and ROIs. Moreover, the energy characteristic was not indicated. This research demonstrated that the accuracy of MTF measurement with the micro-disk method was greater than that with the bead method, and it was found that there was no influence on the actual measurement level of the geometric structure with the micro-disk method. (author)

Comparative study of multi-slice spiral CT angiography and color doppler ultrasound in diagnosis of arteriosclerotic occlusive disease of lower extremity

International Nuclear Information System (INIS)

Li Wanjun; Lai Zhenhui; Cui Dong; Lin Xiupeng; Du Muxuan

2010-01-01

Objective: To compare the difference between multi-slice spiral CT angiography (MSCTA) and color doppler ultrasound in diagnosis of arteriosclerotic occlusive disease of lower extremity. Methods: Patients with arteriosclerosis occlusion were assessed by color doppler ultrasound, multi-slice spiral CT angiography and digital subtraction angiography (DSA). The image information of color doppler ultrasound and MSCTA were compared with that of DSA. Results: Color doppler ultrasound showed the anatomical shape and hemodynamics of the arteries of lower extremity. The sensitivity, specificity, and accuracy for diagnosis arteriosclerotic occlusive disease of lower extremity were 88.04%, 90.69% and 88.77% respectively. MSCTA showed the three dimensional structure of the arteries of lower extremity as well as the collateral arteries and the distal arterials. The sensitivity, specificity and accuracy of MSCTA were 97.69%, 96.90% and 97.66%, respectively. Conclusion: Multi-slice spiral CT angiography is an ideal imaging method for the diagnosis of arteriosclerotic occlusive disease of lower extremity. (authors)

Metacognitive and social cognition training (MSCT) in schizophrenia: a preliminary efficacy study.

Science.gov (United States)

Rocha, Nuno B F; Queirós, Cristina

2013-10-01

Psychosocial interventions have proven to be effective in treating social cognition in people with psychotic disorders. The current study aimed to determine the effects of a metacognitive and social cognition training (MSCT) program, designed to both remediate deficits and correct biases in social cognition. Thirty-five clinically stable outpatients were recruited and assigned to the MSCT program (n=19) for 10 weeks (18 sessions) or to the TAU group (n=16), and they all completed pre- and post-treatment assessments of social cognition, cognitive biases, functioning and symptoms. The MSCT group demonstrated a significant improvement in theory of mind, social perception, emotion recognition and social functioning. Additionally, the tendency to jump to conclusions was significantly reduced among the MSCT group after training. There were no differential benefits regarding clinical symptoms except for one trend group effect for general psychopathology. The results support the efficacy of the MSCT format, but further development of the training program is required to increase the benefits related to attributional style. © 2013 Elsevier B.V. All rights reserved.

The application of spiral-CT and 3D-imaging of airway for observation of efficacy and complication after tracheobronchial stent placement

International Nuclear Information System (INIS)

Wei Ning; Xu Hao; Zu Maoheng; Gu Yuming; Li Gang; Zhang Qingqiao; Xu Wei; Cui Yanfeng; Liu Hongtao; Wang Wenliang

2012-01-01

Objective: To evaluate the application of spiral-CT and 3D-imaging of airway for observation of efficacy and complication after tracheobronchial stent placement. Methods: Thirty-one patients treated with tracheal stents were retrospectively analyzed, of which there were 27 malignant tracheal stenosis, 2 benign tracheal stenosis, 1 bronchial remnant fistula and 1 gastroesophageal anastomosis tracheal fistula. The spiral-CT and 3D-imagings were analyzed and the location, shape and complication of the stents were assessed. Results: Thirty-one patients were treated with 8 Z-type stainless steel stents and 28 Ni-Ti memory alloy stents. The stents of 22 cases remained patent in the original position and restenosis was occurred in 5 cases, migration in 3 cases and fracture in 1 case. All the CT features were performed and reconstructed on the workstation, using multiplanar reconstruction, volume rendering, and CT virtual endoscopy. The location of tracheal stenosis and fistula were showed in different angle, and the location, shape of the stents, and the complications (such as restenosis, fracture) as well. Conclusion: Spiral-CT and 3D-imaging is a rapid, simple and effective method in assessing tracheal stent implantation and complication, therefore, it is of great value in clinical practice. (authors)

Multislice CT imaging of anomalous coronary arteries

International Nuclear Information System (INIS)

Shi Heshui; Aschoff, Andrik J.; Brambs, Hans-Juergen; Hoffmann, Martin H.K.

2004-01-01

The purpose of the present study was to evaluate the role of 16 multislice computed tomography (MSCT) to identify the origin of anomalous coronary arteries and to confirm their anatomic course in relation to the great vessels. Accuracy of coronary artery disease (CAD) detection was a secondary aim and was tested with conventional angiograms (CA) serving as standard of reference. Two hundred and forty-two consecutive patients referred for noninvasive coronary CT imaging were reviewed for the study. Sixteen patients (6.6%) with anomalous coronary arteries were detected and included as the study group. MSCT and CA images were analyzed in a blinded fashion for accuracy of anomalous artery origin and path detection. Results were compared in a secondary consensus evaluation. Accuracy ratios to detect CAD with MSCT in all vessels were calculated. Coronary anomalies for all 16 patients were correctly displayed on MSCT. CA alone achieved correct identification of the abnormality in only 53% (P=0.016). Sensitivity and specificity of MSCT to detect significantly stenosed vessels was 90 and 92%. 16-MSCT is accurate to delineate abnormally branching coronary arteries and allows sufficiently accurate detection of obstructive coronary artery disease in distal branches. It should therefore be considered as a prime non-invasive imaging tool for suspected coronary anomalies. (orig.)

MSCT findings in a controlled bus bombing using a pig model

DEFF Research Database (Denmark)

Hansen, Nikolaj Friis

2009-01-01

and recovering relevant foreign bodies that might have been used in the bomb to inflict more damages to bystanders. The author will present MSCT findings and the injuries found at autopsy in 10 dead pigs were positioned inside the bus in a controlled explosion. This will be done in correlation to the individual...... of the findings. 3D reconstructions of the MSCT studies using the Osirix Viewer were made to visualize injuries and foreign bodies. Results of these findings will be presented to demonstrate the advantages of MSCT to aid forensic pathologists and police investigators in understanding the injury types, patterns...

Spiral CT biliary virtual endoscopy: preliminary clinical applications in the detection of biliary calculus

International Nuclear Information System (INIS)

Xiong Minghui; Wang Dong; Song Yunlong; Zhang Wanshi; Xu Jiaxing

2000-01-01

Objective: To evaluate imaging features and clinical value of CT biliary virtual endoscopy in the detection of biliary calculus. Methods: Eighteen patients with biliary calculi underwent volume scanning using spiral CT (Hispeed Advantage CT/i GE ). All data were transferred to computer workstation, and CT biliary virtual endoscopy images with pseudocolor encoding were generated from the volumetric data using the Navigator Smooth soft-ware. All cases were proved by ultrasound, axial CT or operation. Results: Among 18 cases, gallstones were found 8 in cases, common bile duct stones in 2 cases, gallstones and bile duct stones in 6 cases. The stones were 0.3-3.2 cm in size. CT biliary virtual endoscopy correctly demonstrated the surface details of stones which were viewed from extra- or intraluminal orientation in a 3D fashion. The findings were consistent with those of US, CT or operation. Conclusion: The CT virtual biliary endoscopy is a further development of virtual endoscopy for observing biliary calculus from intra- and extra-luminal views and providing three dimensional information of stone

Assessment of hemodynamics in a rat model of liver cirrhosis with precancerous lesions using multislice spiral CT perfusion imaging.

Science.gov (United States)

Ma, Guolin; Bai, Rongjie; Jiang, Huijie; Hao, Xuejia; Ling, Zaisheng; Li, Kefeng

2013-01-01

To develop an optimal scanning protocol for multislice spiral CT perfusion (CTP) imaging to evaluate hemodynamic changes in liver cirrhosis with diethylnitrosamine- (DEN-) induced precancerous lesions. Male Wistar rats were randomly divided into the control group (n = 80) and the precancerous liver cirrhosis group (n = 40). The control group received saline injection and the liver cirrhosis group received 50 mg/kg DEN i.p. twice a week for 12 weeks. All animals underwent plain CT scanning, CTP, and contrast-enhanced CT scanning. Scanning parameters were optimized by adjusting the diatrizoate concentration, the flow rate, and the delivery time. The hemodynamics of both groups was further compared using optimized multislice spiral CTP imaging. High-quality CTP images were obtained with following parameters: 150 kV; 150 mAs; 5 mm thickness, 5 mm interval; pitch, 1; matrix, 512 × 512; and FOV, 9.6 cm. Compared to the control group, the liver cirrhosis group had a significantly increased value of the hepatic arterial fraction and the hepatic artery perfusion (P spiral CTP imaging can be used to evaluate the hemodynamic changes in the rat model of liver cirrhosis with precancerous lesions.

Mycotic Aneurysm of the Celiac Trunk: From Early CT Sign to Rupture

International Nuclear Information System (INIS)

Serafino, Gianpiero; Vroegindeweij, Dammis; Boks, Simone; Harst, Erwin van der

2005-01-01

We present a case of the rapid development and rupture of a mycotic celiac trunk aneurysm. Initiallyon multislice computed tomography (ms-CT) there was a normal celiac trunk with minimal haziness of the surrounding fat. Only 2 weeks later the patient went into hypovolemic shock due to a ruptured celiac aneurysm. Although aneurysms of the visceral arteries are rare, they are of major clinical importance as they carry a life-threatening risk of rupture. This case illustrates the use of ms-CT in detecting and evaluating visceral aneurysms, in order to prevent emergency operation

Intra-individual diagnostic image quality and organ-specific-radiation dose comparison between spiral cCT with iterative image reconstruction and z-axis automated tube current modulation and sequential cCT

Directory of Open Access Journals (Sweden)

Holger Wenz

2016-01-01

Conclusions: Spiral cCT combined with ATCM and IR allows for significant-radiation dose reduction including a reduce eye lens organ-dose when compared to a tilted sequential cCT while improving subjective and objective image quality.

Spiral CT of the pancreas. The value of small field-of-view targeted reconstruction

International Nuclear Information System (INIS)

Nishiharu, T.; Yamashita, Y.; Ogata, I.; Sumi, S.; Mitsuzaki, K.; Takahashi, M.

1998-01-01

Purpose: To compare the value of a retrospective targeted high-resolution spiral CT to the standard reconstruction technique in the assessment of pancreatic diseases. Material and methods: Spiral CT pancreatic images of a standard-size reconstruction protocol were compared prospectively with those of a retrospective targeted high-spatial-resolution reconstruction protocol in 30 patients. Prior to clinical evaluation, a phantom study was performed to evaluate the spatial resolution and signal-to-noise ratio of both protocols. Results: The high-resolution protocol achieved a good signal-to-noise ratio with acceptable spatial resolution. Phantom studies revealed increased image noise (+17%) with an increase in spatial resolution (+100%). In patients studied with the high-resolution protocol, the increase in noise was not significant but there was a marked improvement in the definition of small details. Conclusion: Images obtained with a targeted high-spatial-resolution reconstruction protocol showed superior lesion definition and vascular opacification compared with those obtained with a standard-size reconstruction protocol. This technique may have potential in the evaluation of small pancreatic abnormalities. (orig.)

Use of spiral CT in demonstrating early carcinoma of the stomach - I stage

International Nuclear Information System (INIS)

Pomakov, P.

2009-01-01

Full text: The aim of this lecture is to provide practical information about the methodology and technique of spiral computed tomography, which provide maximum diagnostic efficiency in early gastric cancer - I stage, and to present the semiotics of CT images seen in early gastric cancer stage I - a own and literature data. Methodology of the study covers optimal drug muscle relaxation of the abdominal wall by injection of 2 sg buskolizin intravenous; maximum distension of the stomach lumen by ingestion of 3 effervescent disintegrated tablets Vit. C with 1-2 sips of water, necessarily using of non-ionic contrast media - 100 ml / 300 mg iodine / 1 ml liquid bolus introduced for 30 seconds. Start scanning - 30 seconds of the start of injection - to visualize the arterial phase, use of slices with a thickness of 3 mm and 2 mm interval; exponential data 120 kV, 160 mAc. Earlier form of gastric cancer have to be presented by 5 CT image: unequal unsmooth, scallop or polycyclic contours of the lining, thinning the complete disappearance of the lining; undulating thickening of the lining; nodal formation like a polyp on a broad basis with a 2-5 mm, double contour of the lining - like a wave. These amendments are localized only in a limited segment of the gastric mucosa. Spiral CT is an effective diagnostic performance in gastric cancer, including the early stage I of cancer development. This is realized only by using the specific methodology of the study as well as good knowledge of the CT images semiology for carcinoma, localized only within a certain perimeter of the stomach lining

Accuracy of spiral CT and 3D reconstruction in the detection of acute pulmonary embolism - development of an animal model using porcine lungs and technical specimens. Development of an animal model using porcine lungs and technical specimens; Diagnostik der akuten Lungenembolie mittels Spiral-CT und 3D-Rekonstruktion. Entwicklung eines Tiermodells und technischer Probekoerper im Ex-vivo-Experiment

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Ries, B.G. [Klinik und Poliklinik fuer Radiologie, Univ. Mainz (Germany); Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany); Kauczor, H.U.; Thelen, M. [Klinik und Poliklinik fuer Radiologie, Univ. Mainz (Germany); Konerding, M.A. [Anatomisches Inst., Mainz Univ (Germany)

2001-02-01

Purpose: To develop a model for simulation the CT morphologic situation of acute pulmonary embolism, to evaluate the accuracy of spiral CT and 3D reconstruction in the detection of artificial emboli and to investigate the influence of the orientation of emboli depending on z-axis orientation. Materials and Methods: Standardized artificial emboli made of wax and of defined size and shape were positioned into the pulmonary arteries of porcine lungs. Castings of the embolized pulmonary arterial trees were made by injection of a special opaque resin. After performance of spiral CT the data sets of the emboli and the pulmonary arteries were post-processed. The 3D segmentations were compared with the anatomic preparation to evaluate the accuracy of spiral CT/3D reconstruction-technique. Technical specimens simulating CT-morphology of acute embolized vessels underwent spiral CT in six different positions with respect to the z-axis. The CT data were reconstructed using a standardized and a contrastadapted method with interactive correction. The 3D emboli were analysed under qualitative aspects, and measurements of their extent were done. Results: In nearly 91%, there was complete agreement between CT and the corresponding findings at the anatomical preparation. Measurements of the 3D reconstructed technical specimens showed discrepancies of shape and size in dependence of the size of the original preparation, orientation and reconstruction technique. Overestimation up to 4 mm and underestimation to 2,2 mm were observed. Measurements of preparations with heights from 14 to 26 mm showed variances of {+-}1,5 mm ({proportional_to}6-11%). Conclusion: The presented models are suitable to simulate CT morphology of acute pulmonary embolism under ex-vivo conditions. Accuracy in the detection of artificial emboli using spiral CT/3D reconstruction is affected by localization, size and orientation of the emboli and the reconstruction technique. (orig.) [German] Ziel: Die Entwicklung

A comparative study for spatial resolution and subjective image characteristics of a multi-slice CT and a cone-beam CT for dental use

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Honda, Eiichi; Tetsumura, Akemi; Kurabayashi, Tohru

2011-01-01

Purpose: Multi-slice CT (MSCT) and cone-beam CT (CBCT) are widely used in dental practice. This study compared the spatial resolution of these CT systems to elucidate which CT modalities should be selected for various clinical cases. Materials and methods: As MSCT and CBCT apparatuses, Somatom Sensation 64 and 3D Accuitomo instruments, respectively, were used. As an objective evaluation of spatial resolution of these CT systems, modulation transfer function (MTF) analysis was performed employing an over-sampling method. The results of MTF analysis were confirmed with a line-pair test using CATPHAN. As a subjective evaluation, a microstructure visualization ability study was performed using a Jcl:SD rat and a head CT phantom. Results: MTF analysis showed that for the in-plane direction, the z-axis ultrahigh resolution mode (zUHR) of the Sensation 64 and 3D Accuitomo instruments had higher spatial resolutions than the conventional mode (64x) of the Sensation 64, but for the longitudinal direction, the 3D Accuitomo had clearly higher spatial resolution than either mode of the Sensation 64. A line-pair test study and microstructure visualization ability studies confirmed the results for MTF analysis. However, images of the rat and the CT phantom revealed that the 3D Accuitomo demonstrated the failure to visualize the soft tissues along with aliasing and beam-hardening artifacts, which were not observed in the Sensation 64. Conclusions: This study successfully applied spatial resolution analysis using MSCT and CBCT systems in a comparative manner. These findings could help in deciding which CT modality should be selected for various clinical cases.

Pericardial sinuses and recesses effusion of 16-slice helical CT imaging and anatomic correlation

International Nuclear Information System (INIS)

Lu Chunyan; Yang Zhigang; Zhou Xiangping; Yu Jianqun; Zhu Jie; Yang Kaiqing

2007-01-01

Objective: To evaluate the CT features and implications of the pericardial sinuses and recesses effusion by combining the sectional cadavers and 16 multi-slice CT (MSCT) reformation. Methods: The anatomy and communication of the pericardial sinuses and recesses on the axial, coronal and saggital sectional cadavers (respectively 1 case), and the morphologic features on MSCT reformatted images in 104 patients were observed. The detection rate of effusion was analyzed. Results: The sectional cadavers and CT images showed that the pericardial sinuses and recesses were formed by the reflections of the pericardium on the root of the great vessels. The detection rate of the sinuses and recesses was lower in small effusion than in moderate and large effusion (P<0.05). The superior aortic recess was the most common recess for pericardial effusion. Conclusion: The MSCT reformatted images can show the morphologic features of pericardial sinuses and recesses effusion and communications with the pericardial cavity, help differentiate pericardial effusion from other mediastinal or pericardial lesions. (authors)

Power doppler ultrasound findings of renal infarct after experimental renal artery occlusion: comparison with spiral CT

International Nuclear Information System (INIS)

Jung, Seung Eun; Shinn, Kyung Sub; Kim, Hak Hee; Mun, Seok Hwan; Lee, Young Joon; Lee, Bae Young; Choi, Byung Gil; Lee, Jae Mun; Lee, Hee Jeong

1999-01-01

To evaluate the efficacy of power Doppler ultrasonography (PDUS) in depicting renal infarction in rabbits during experimental renal segmental arterial occlusion, and to compare the results with those of CT scanning. In 28 rabbits weighing 2.5 4kg, the segmental renal artery was occluded through the left main renal artery by embolization with Ivalon (Nycomed, Paris, France). Power Doppler ultrasonography and spiral CT scanning were performed before and at 2, 5, 8, 15, and 24 hours, and 3 and 7 days after occlusion of the segmental renal artery. The location of infarcted areas and collaterals, as seen on PDUS and CT scans, was evaluated by two radiologists. In all cases, as seen on power Doppler ultrasonography, infarcted areas-when compared with normal parenchyma, clearly demonstrated wedge-shaped perfusion defects in the kidney. The location of the lesion closely corresponded to the location seen during CT scanning. After renal arterial occlusion, transiently congested capsular arteries, which were named 'capsular sign', were seen in 63% of rabbits in the two and five-hour groups. No significant cortical rim sign was demonstrated on power Doppler ultrasonography, though it was noted on spiral CT at 15 and 24 hours, and 3 and 7 days after renal arterial occlusion. Power Doppler ultrasonography was useful for the diagnosis of renal infarction. Congested capsular artery seen in the early stage of renal infarction might be a characteristic finding of this condition, as seen on power Doppler ultrasonography

Classification of fractures of the distal r[ius - Comparative evaluation of spiral CT images and X-rays

International Nuclear Information System (INIS)

Roehnert, W.; Nitzsche, H.; Franck, W.M.; Amlang, M.

1998-01-01

Within the framework of a prospective study 35 patients with fractures of the distal r[ius safely diagnosed to require surgery have been [ditionally scanned by spiral CT. For more exact diagnostic evaluation of the joint surfaces and the fractures, multiplane reconstructions have been m[e to enhance the information obtained from the primary, axial tomographic images. Two experts independently performed classification on the basis of the X-rays and the CT scans, applying the AO scheme and the method of Frykman. Classifications according to the AO scheme were found to agree for only 28.6 % of the patients, which means that 57.1 % of the fractures shown by the X-rays were more or less underassessed. Classification according to Frykman's method revealed fewer deviations and agreement in 51.4 % of the cases. Biplanar r[iography continues to be considered as the standard method for examination of distal r[ius fractures, but it is recommended to perform spiral CT scans for evaluation of more complex distal r[ius fractures because these may require different therapies according to fracture types. (orig./CB) [de

Motion estimation and compensation in dynamic spiral CT reconstruction

International Nuclear Information System (INIS)

Kimdon, J.; Grangeat, P.; Koenig, A.; Bonnet, St.

2004-01-01

Respiratory and cardiac motion causes blurring in dynamic X-ray Computed Tomography (CT). Fast scans reduce this problem, but they require a higher radiation dose per time period to maintain the signal to noise ratio of the resulting images, thereby magnifying the health risk to the patient. As an alternative to increased radiation, our team has already developed a cone-beam reconstruction algorithm based on a dynamic particle model that estimates, predicts, and compensates for respiratory motion in circular X-ray CT. The current paper presents an extension of this method to spiral CT, applicable to modern multi-slice scanners that take advantage of the speed and dose benefits of helical trajectories. We adapted all three main areas of the algorithm: backprojection, prediction, and compensation/accumulation. In backprojection, we changed the longitudinal re-binning technique, filter direction, and the method of enforcing the data sufficiency requirements. For prediction, we had to be careful of objects appearing and disappearing as the scanner bed advanced. For compensation/accumulation, we controlled the reconstruction time and combined images to cover a greater longitudinal extent for each phase in the respiratory or cardiac cycle. Tests with moving numerical phantoms demonstrate that the algorithm successfully improves the temporal resolution of the images without increasing the dose or reducing the signal-to-noise ratio. (authors)

Clinical application of 3D spiral CT of the auditory ossicular chain and labyrinth: Preliminary report

International Nuclear Information System (INIS)

Huang Yong; Wang Yisheng

1998-01-01

Purpose: To assess the clinical application and limitation of 3D spiral CT of the auditory ossicular chain and labyrinth. Methods: 3D reconstruction of the auditory ossicular chain and labyrinth, including multiplanar reformation (MPR), minimum or maximum intensity projection (MinIP or MaxIP) and shaded surface display (SSD), were performed with 1 mm slice thickness, 5 cm field of view and 0.1 mm reconstruction interval spiral CT in 14 normal subjects, 15 patients with middle ear diseases. Results: With use of 3D reconstruction images in 14 normal subjects, 13 cases of ossicular chain showed that the long process of the incus was parallel to the manubrium and projected inferomedian toward the cochlear promontory, the incus-stapedial joint was like a 'L-shape' structure, and in 8 cases of labyrinth reconstruction, the cochlea and the three semicircular canals were demonstrated. 9 cholesteatomas of 13 chronic otitis media demonstrated destruction of ossicular chain of varying degrees. In 2 cases with congenital abnormality, ossicle dysplasia was seen. Conclusion: 3D CT is a useful technique for evaluating anatomic malformations and diseases of middle and inner ear, but there are still few pitfalls

Accuracy of automated volumetry of pulmonary nodules across different multislice CT scanners

International Nuclear Information System (INIS)

Das, Marco; Muehlenbruch, Georg; Mahnken, Andreas H.; Katoh, Markus; Guenther, Rolf W.; Wildberger, Joachim E.; Ley-Zaporozhan, Julia; Kauczor, Hans-Ulrich; Gietema, H.A.; Prokop, Mathias; Czech, Andre; Diederich, Stefan; Bakai, Annemarie; Salganicoff, Marcos

2007-01-01

The purpose of this study was to compare the accuracy of an automated volumetry software for phantom pulmonary nodules across various 16-slice multislice spiral CT (MSCT) scanners from different vendors. A lung phantom containing five different nodule categories (intraparenchymal, around a vessel, vessel attached, pleural, and attached to the pleura), with each category comprised of 7-9 nodules (total, n = 40) of varying sizes (diameter 3-10 mm; volume 6.62 mm 3 -525 mm 3 ), was scanned with four different 16-slice MSCT scanners (Siemens, GE, Philips, Toshiba). Routine and low-dose chest protocols with thin and thick collimations were applied. The data from all scanners were used for further analysis using a dedicated prototype volumetry software. Absolute percentage volume errors (APE) were calculated and compared. The mean APE for all nodules was 8.4% (±7.7%) for data acquired with the 16-slice Siemens scanner, 14.3% (±11.1%) for the GE scanner, 9.7% (±9.6%) for the Philips scanner and 7.5% (±7.2%) for the Toshiba scanner, respectively. The lowest APEs were found within the diameter size range of 5-10 mm and volumes >66 mm 3 . Nodule volumetry is accurate with a reasonable volume error in data from different scanner vendors. This may have an important impact for intraindividual follow-up studies. (orig.)

Preoperative assessment of gastric artery in patients with gastric cancer by CT angiography on 64-slice spiral CT

International Nuclear Information System (INIS)

Tang Lei; Zhang Xiaopeng; Sun Yingshi; Cao Kun; Qi Liping; Cui Yong; Wang Ning

2010-01-01

Objective: To evaluate the efficacy of different three-dimensional CTA methods on 64-slice sprial CT in the preoperative assessment of gastric arteries and their variations. Methods: Sixty-six consecutive patients with gastric cancer who underwent 64-slice spiral CT examinations preoperatively were retrospectively studied. To get the STS-MIP images, the thickness of slab was adjusted according to the inner diameter of targeted blood vessels and their cross-layer distribution. After four weeks, the AVVR images of all cases was got by the auto-vessel technique. The demonstration rates and origins of the direct and indirect feeding arteries were analyzed on AVVR and STS-MIP. McNemar tests were used to compare the detection rates of gastric feeding arteries by STS-MIP and AVVR. The relationship between CT value and display rate of vessels was analyzed using independent-samples t test. The variations of blood vessels were analyzed. Results: The display rate of indirect feeding arteries were all 100% (66/66) by STS-MIP and AVVR. The display rates of left gastric artery (LGA) and right gastroepiploic artery (RGEA) were 98.5% (65/66), 100.0% (66/66) and 97.0% (64/66), 100.0% (66/66) by STS-MIP and AVVR respectively. The display rates of right artery (RGA), left gastroepiploic artery (LGEA), short gastric artery (SGA) and posterior gastric artery (RGA), left gastroepiploic artery (LGEA), short gastric artery (SGA) and posterior gastric artery (PGA) by AVVR were lower than those of STS-MIP with statistical significances [RGA: 68.2% (45/66) vs. 98.5% (65/66), P<0.01; LGEA: 53.0% (35/66) vs. 97.0% (64/66), P<0.01; SGA: 7.6%(5/66) vs. 59.1% (39/66), P<0.01; PGA: 18.2% (12/66) vs. 63.6% (42/66), P<0.01]. The demonstration rates of LGEA, RGEA and SGA increased accompanied with the increasing of CT value in celiac axis (LGEA: 35 cases displayed with mean CT value of (272 ± 44) HU, 31 cases did not display with mean CT value of (229 ± 42) HU, t=4.043, P<0.01; RGEA: 64 cases

To evaluate vascular complications of transplant kidney examined by multislice spiral CT angiograph

International Nuclear Information System (INIS)

Peng Qian; Fan Miao; Luo Xiaomei

2008-01-01

Objective: To evaluate the value of multislice CT angiography (MSCTA) in vascular complications of transplant kidney. Methods: Six transplant kidneys were undergone enhanced MSCT scanning postoperation. MPR, CPR, VR and VP reformation were performed to observe transplant kidney's parenchyma, renal artery, and renal vein. To analysis all the reconstruction technique and find the advantage and shortage of them. Results: One case showed enhanced function of transplant kidney decreased. Vascular stenosis was found in one case and false aneurysm was found in another transplant kidney. Transplant kidney were enhanced normal in the left three cases. MPR couldn't reconstruct all the tortuous vessel of renal hilus in one plane. But all six cases could expose the vessel of renal hilus very clearly in coronal section and sagittal plane of CPR. Six cases of VR could observe the vessel direction and lesions outside vessel through rotate the reconstruction image. VP could see through inside the vessel of transplant kidney. Conclusion: MSCTA has an important role as an imaging technique to evaluate vascular complications of transplant kidney, it can replace DSA. (authors)

Accuracy and reliability of different cone beam computed tomography (CBCT) devices for structural analysis of alveolar bone in comparison with multislice CT and micro-CT.

Science.gov (United States)

Van Dessel, Jeroen; Nicolielo, Laura Ferreira Pinheiro; Huang, Yan; Coudyzer, Walter; Salmon, Benjamin; Lambrichts, Ivo; Jacobs, Reinhilde

The aim of this study was to assess whether cone beam computed tomography (CBCT) may be used for clinically reliable alveolar bone quality assessment in comparison to its clinical alternatives, multislice computed tomography and the gold standard (micro-CT). Six dentate mandibular bone samples were scanned with seven CBCT devices (ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170, Carestream 9300, Scanora 3D, I-CAT Next generation), one micro-CT scanner (SkyScan 1174) and one MSCT machine (Somatom Definition Flash) using two protocols (standard and high-resolution). MSCT and CBCT images were automatically spatially aligned on the micro-CT scan of the corresponding sample. A volume of interest was manually delineated on the micro-CT image and overlaid on the other scanning devices. Alveolar bone structures were automatically extracted using the adaptive thresholding algorithm. Based on the resulting binary images, an automatic 3D morphometric quantification was performed in a CT-Analyser (Bruker, Kontich, Belgium). The reliability and measurement errors were calculated for each modality compared to the gold standard micro-CT. Both MSCT and CBCT were associated with a clinically and statistically (P max, bone surface density -0.47 mm-1 min to 0.16 mm-1 max and trabecular thickness 0.15 mm min to 0.31 mm max) were significantly (P max and fractal dimension 0.08 min to 0.17 max) in all scanners compared to micro-CT. However, the structural pattern of the alveolar bone remained similar compared to that of the micro-CT for the ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170 and Carestream 9300. On the other hand, the Scanora 3D, i-CAT Next Generation, standard and high-resolution MSCT displayed an overrated bone quantity and aberrant structural pattern compared to other scanning devices. The calculation of morphometric indices had an overall high reliability (intraclass correlation coefficient [ICC] 0.62 min to 0.99 max), except

MSCT在主动脉壁内血肿诊断和转归中的应用%Application of multi-slice spiral CT in diagnosis and prognosis of aortic artery intramural hematoma

Institute of Scientific and Technical Information of China (English)

黄源义; 谢欢; 邬正宏; 刘四斌

2011-01-01

Objective To investigate the applied value of multi-slice spiral CT in diagnosis and prognoses of aortic artery intramural hematoma(IMH). Methods 11 patients with IMH underwent plain CT scan and CT angiography with 16-slice spiral CT of GE. Endovascular stent for the treatment in 3 cases and conservative treatment in 8 cases was performed. All patients were followed-up twice or 4 times for 15 - 210 days(mean 112. 5 days). Results 3 cases with Stanford A and 8 cases with Stanford B IMH were diagnosed. The main CT findings were as follows: Crescent or circular thickening(>5 mm)of aortic wall with higher density or isodensi-ty without intimal flap as well as true and false lumen in 11 cases;atherosclerosis in 7 cases;intimal calcification ingression in 4 cases; intimal leakages in 3 cases;penetrating ulcer in 3 cases. The hematomas in 7 cases were completely absorbed,incomplete absorbed in 2 cases,while 2 cases were transformed to dissecting aneurysm. Conclusion MSCT is a significant method in diagnosis and follow-ing-up of IMH, and can provide important informations for clinical treatment.%目的 探讨MSCT在主动脉壁内血肿(IMH)诊断和转归中的应用价值.方法 采用GE 16排螺旋CT对11例IMH行平扫和CTA扫描.3例行腔内支架隔绝术,8例保守治疗.所有病例治疗后随访2～4次,随访时间15～210 d(平均112.5 d).结果 A型IMH 3例,B 型IMH 8例.MSCT主要征象为:11例主动脉壁新月形或环形增厚＞5 mm,呈等密度或高密度,无内膜片撕裂及真、假两腔形成;主动脉粥样硬化7例;内膜钙化内移4例;内膜渗漏3例;穿透性溃疡3例.7例完全吸收,2例部分吸收,2例进展成夹层动脉瘤.结论 MSCT能对IMH作出明确的诊断,并可作为IMH随访的重要检查手段,对临床治疗有重要的指导意义.

Multi-slice CT pulmonary function evaluation in emphysema

International Nuclear Information System (INIS)

Ge Xiaojun; Zhang Guozhen; Zhu Yanping; Shan Lin; Mao Dingbiao; Ding Qiyong; Hua Yanqing

2007-01-01

Objective: To explore the feasibility of evaluating the lung function by MSCT in emphysema. Methods: The MSCT scan and pulmonary function tests (PFT) were respectively performed in 147 receptors within one week. They were randomly divided into 2 groups: group A (120 receptors), including normal, mild, moderate and severe abnormal pulmonary function based on the PFT, for comparing the correlation between pulmonary quantitative indexes of MSCT pulmonary function and PFT and settingup the primary, grade criteria of abnormal pulmonary, function in emphysema, group B (27 receptors) for evaluating the diagnostic accuracy in group A. The total lung was respectively scanned at the full inspiration and full expiration with MSCT. The pulmonary quantitative indexes of MSCT were measured with Siemens Pulmo pulmonary quantitative software. Results: There was correlation between pulmonary quantitative indexes of MSCT and PFT. The Piex/in -910 showed best correlation with FEV 1 % (r= -0. 905, P -910 (χ 2 0.267, P=0.966, accuracy 81.5%), and the primary criteria for abnormal pulmonary, function of emphysema was normal (0-9.9), mild (10.0-34.9), moderate (35.0-74.9) and severe (≥75.0). Conclusion: It is feasible to evaluate the abnormal lung function of emphysema with pulmonary quantitative indexes of CT. The Piex/in 910 was the most effective one in various indexes. (authors)

Accuracy of liver lesion assessment using automated measurement and segmentation software in biphasic multislice CT (MSCT)

International Nuclear Information System (INIS)

Puesken, M.; Juergens, K.U.; Edenfeld, A.; Buerke, B.; Seifarth, H.; Beyer, F.; Heindel, W.; Wessling, J.; Suehling, M.; Osada, N.

2009-01-01

Purpose: To assess the accuracy of liver lesion measurement using automated measurement and segmentation software depending on the vascularization level. Materials and Methods: Arterial and portal venous phase multislice CT (MSCT) was performed for 58 patients. 94 liver lesions were evaluated and classified according to vascularity (hypervascular: 13 hepatocellular carcinomas, 20 hemangiomas; hypovascular: 31 metastases, 3 lymphomas, 4 abscesses; liquid: 23 cysts). The RECIST diameter and volume were obtained using automated measurement and segmentation software and compared to corresponding measurements derived visually by two experienced radiologists as a reference standard. Statistical analysis was performed using the Wilcoxon test and concordance correlation coefficients. Results: Automated measurements revealed no significant difference between the arterial and portal venous phase in hypovascular (mean RECIST diameter: 31.4 vs. 30.2 mm; p = 0.65; κ = 0.875) and liquid lesions (20.4 vs. 20.1 mm; p = 0.1; κ = 0.996). The RECIST diameter and volume of hypervascular lesions were significantly underestimated in the portal venous phase as compared to the arterial phase (30.3 vs. 26.9 mm, p = 0.007, κ 0.834; 10.7 vs. 7.9 ml, p = 0.0045, κ = 0.752). Automated measurements for hypovascular and liquid lesions in the arterial and portal venous phase were concordant to the reference standard. Hypervascular lesion measurements were in line with the reference standard for the arterial phase (30.3 vs. 32.2 mm, p 0.66, κ = 0.754), but revealed a significant difference for the portal venous phase (26.9 vs. 32.1 mm; p = 0.041; κ = 0.606). (orig.)

Characteristics and application of inner ear CT in 20 cases of sensorineural hearing loss in children.

Science.gov (United States)

Huo, Liang; Wang, Hua

2012-12-01

This study shows that a number of children with sensorineural hearing loss (SNHL) have inner ear malformations demonstrated by multi-slice spiral computed tomography (MSCT). MSCT allows a comprehensive assessment of various congenital inner ear malformations through high quality multiplanar reformation (MPR) and can display the site and degree of the malformation three-dimensionally and intuitively. This is very useful for cochlear implantation. To evaluate the feasibility and usability of MSCT in pediatric SNHL with inner ear malformations. Sixty-five patients were diagnosed with SNHL by brainstem auditory evoked response (BAER). Inner ear MSCT scan and coronal MPR reconstruction were performed in all cases. This study demonstrated 20 cases (33 ears) with inner ear malformations, which included 10 ears with cochlear malformations, 7 with vestibular malformations, 5 with semicircular canal malformations, 8 with internal auditory canal (IAC) malformations, and 15 with vestibular malformations. Cochlear malformations included one ear with Michel deformity, two ears with common cavity deformity, one with cochlear aplasia, one with hypoplastic cochlea, two with incomplete partition type I, and three with incomplete partition type II (Mondini deformity).

TRIPLE PHASE SPIRAL C.T. IN THE EVALUATION OF HEPATIC MASSES

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Prasad

2015-10-01

Full Text Available BACKGROUND AND OBJECTIVE : The goal of the study is to determine the value of various phases of Triple, Helical CT, Hepatic arterial Phase (HAP, Portal venous phase (PVP and Equilibrium Phase (EP, is the detection and characterization of Hepatic Lesions and to evaluate whether u nenhanced and hepatic arterial phases when used in conjunction with porto venous phase would lead to detection of greater number of lesions or better characterization of lesion. METHODOLOGY : The study population consists of 50 Patients aged between 30 Years and 80 Years were examined with multiphase (plain, hepatic arterial, portal venous and equilibrium phases. Spiral CT of liver. Patients were referred for CT scan when liver diseases were suspected clinically, if ultrasound and other previous investi gations revealed lesions which had to be further evaluated by spiral CT and to detect liver metastases in known cases of primary extra hepatic malignancy. CT TECHNIQUE: Helical scanning of liver with Toshiba astein s4, continuous spiral run and the images were reconstructed at 5mm intervals. Contrast material 100ml was injected through 18 or 20G catheter at the rate of 3ml per second using automatic medrad power injector. Non - ionic contrast [IOHEXOl – 300mg perml was used in all the patients]. After obtaine d unenhanced CT scan HAP scanning was initiated 25 seconds after initiation of contrast injection. Portal venous phase scanning was initiated 60 - 65 seconds after start of contrast injection. Equilibrium phase scanning was initiated after 180 seconds after the start of contrast injection. IMAGE EVALUATION: All the images of 4 phases were reviewed. First Step : The presence, appearance and enhancement of each Lesion were noted in all phases and lesion were described Isodense, Hypodense Hyperdense based on thei r attenuation relative to liver parenchyma during that phase of scanning. Based on enhancement pattern of the lesion during various phases they were

Optimized control of X-ray exposure and image noise using a particular multislice CT scanner

International Nuclear Information System (INIS)

Yamamoto, Shuji; Suzuki, Masahiro; Kakinuma, Ryutaro; Moriyama, Noriyuki; Koyama, Yoshihiro; Nagasawa, Hirofumi

2008-01-01

Patient dose reduction in computed tomography (CT) always results in a trade off between radiation exposure and image quality. There are few reports that estimate the relationship between image quality and X-ray exposure in CT examinations as one optimal index. The purpose of this study was to determine the optimal parameter settings enabling a low radiation exposure without compromising image quality using a particular 4-row multislice CT (MSCT) scanner (Aquilion VZ 4-slice CT scanner, Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan). Normalized dose divided by image noise for helical pitches (nDNR: normalized dose to noise ratio) were calculated in consideration of beam collimation and tube current-time product. Optimal tube current-time product was calculated using the nDNR for the helical pitches based on user-defined standards of quality of the CT image. As a result, the nDNR proved to be well-supported to decrease the patient exposure in various exposure conditions of MSCT scans; however, the dose and image noise did not show a linear relation to the helical pitch. In conclusion, nDNR can be applied to patient dose reduction while keeping an acceptable image quality using a particular 4-row MSCT scanner. (author)

Value of electron beam tomography (EBT). II. non-cardiac applications and radiation exposure

International Nuclear Information System (INIS)

Enzweiler, C.N.H.; Lembcke, A.; Rogalla, P.; Taupitz, M.; Wiese, T.H.; Hamm, B.; Becker, C.R.; Bruening, R.; Reiser, M.F.; Schoepf, U.J.; Felix, R.; Knollmann, F.D.; Georgi, M.; Weisser, G.; Lehmann, K.J.

2004-01-01

Electron beam tomography (EBT) has been scientifically evaluated to a much lesser degree for non-cardiac indications than for cardiac purposes. Therefore, four groups of investigators in Berlin (2), Mannheim and Muenchen, which were supported by the Deutsche Forschungsgemeinschaft (DFG), included applications outside the heart in their evaluation of EBT technology. EBT has proven useful to look for pulmonary embolism and to assess other vessels (aorta, aortic branches, and intracranial arteries). Imaging of the lung parenchyma benefits from its intrinsic high contrast and from the fast data acquisition of EBT. Limited photon efficiency, higher radiation exposure, increased noise levels and other artifacts, however markedly reduce the value of EBT for imaging of low contrast objects compared to conventional spiral CT and multislice CT (MSCT), compromising, in particular, the morphologic depiction of parenchymal abdominal organs and the brain. Consequently, scientific studies to further evaluate EBT for scanning of the brain and parenchymal abdominal organs were not pursued. Radiation exposure for non-cardiac EBT studies is up to three times higher than that for respective spiral CT studies, and in children EBT can only be advocated in select cases. Radiation exposure for the various prospectively triggered cardiac examination protocols of EBT is lower than that for conventional coronary angiography. Radiation exposure in cardiac multislice CT exceeds severalfold that of EBT, but the dose efficiency of EBT and MSCT are similar due to higher spatial resolution and less image noise of MSCT. In addition, modifications of MSCT (ECG pulsing) can further reduce radiation exposure to the level of EBT. Technical improvements of the EBT successor scanner 'e-Speed' enable faster data acquisiton at higher spatial resolution. Within comparative studies, the 'e-Speed' will have to prove its value and competitiveness, particularly in comparison with multislice CT. After profound

CT assessment of tracheobronchial anomaly in left pulmonary artery sling

Energy Technology Data Exchange (ETDEWEB)

Zhong, Yu-Min M.; Zhu, Ming; Sun, Ai-Min M.; Wang, Qian [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Shanghai Children' s Medical Center, Shanghai (China); Jaffe, Richard B. [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States); Gao, Wei [Shanghai Jiao Tong University School of Medicine, Department of Cardiology, Shanghai Children' s Medical Center, Shanghai (China)

2010-11-15

The left pulmonary artery sling (LPAS) is a rare vascular anomaly where the left pulmonary artery arises from the right pulmonary artery, passes over the right bronchus, and goes posteriorly between the trachea and esophagus. The LPAS is frequently associated with cardiac and non-cardiac defects including tracheobronchial abnormalities. To evaluate the utility of multislice CT (MSCT) and helical CT (HCT) in diagnosing and defining the tracheobronchial anomaly and anatomic relationships between the trachea and aberrant left pulmonary artery. MSCT or HCT was performed in 27 children to determine the tracheobronchial anatomy and identify tracheobronchial stenosis. Eighteen children underwent surgery. According to the Wells [6] classification of LPAS, which includes two main types and two subtypes, there were eight cases of type 1A, five cases of type 1B, six cases of type 2A and eight cases of type 2B in this group. Twenty-four of the 27 children had substantial tracheobronchial stenosis. Four died before surgery; the 18 had reanastomosis of the left pulmonary artery. Five children also had tracheoplasty; three died after surgery. CT, especially MSCT, is an ideal modality for simultaneously identifying aberrant left pulmonary artery and any associated tracheobronchial anomaly. The Wells classification is useful for operative planning. (orig.)

Spiral CT: An innovative method of volumetric recording. Pt. 1

International Nuclear Information System (INIS)

Kalender, W.A.; Vock, P.; Polacin, A.; Soucek, M.

1990-01-01

A major advance in the field of CT diagnosis has been made with the development of spiral computed tomography. It permits a complete photographic recording of volumes in such a way that even 'minor' pathological changes can be detected and reconstructed providing the absence of respiration-induced organ displacement. During one session, in which up to 24 360deg scans may be obtained within 24 seconds, the patient is continuously shifted at a speed of 10 mm/s, which permits the volumes recorded to be increased up to a height of 24 cm. The underlying methodology is described, as is the procedure to be used in the reconstruction of planar pictures from the volumes recorded. (orig./GDG) [de

Accuracy and reliability of thyroid volumetry using spiral CT and thyroid volume in a healthy, non-iodine-deficient Chinese adult population

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Shu Jian, E-mail: shujiannc@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Zhao Jiannong, E-mail: zhaojiannong@tom.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Guo Dajing, E-mail: guodaj@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Luo Yindeng, E-mail: yindengluo_1019@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Zhong Weijia, E-mail: zhongweijia2003@eyou.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China); Xie Weibo, E-mail: radiologycq@163.com [Department of Radiology, Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010 (China)

2011-02-15

Objective: The purpose of this study was to assess the accuracy and reliability of thyroid volumetry using spiral CT and to investigate thyroid volumes for a healthy, non-iodine-deficient adult population in southwestern region of China. Materials and methods: Spiral CT was performed in phantoms and adult subjects with normal thyroid, and the volumes were measured by observers with 5 years or more of CT experience. The phantom volumes and the thyroid volumes of all subjects were noted. Results: For the thyroid phantoms, there was no significant difference between the true and CT calculated volumes (t = 0.862, P = 0.399), and the correlation was excellent (ICC = 0.9995, P = 0.000). In the subjects for reliability analysis, the intraobserver or interobserver differences for CT volumetric measurement of thyroid were not significant (P > 0.05). The intraobserver or interobserver correlations were very high (ICC > 0.99, P < 0.001). In the subjects for population analysis, the median of the thyroid volumes was 11.45 cm{sup 3}. The nonparametric Mann-Whitney U-test showed no significant difference for the thyroid volume between sexes (U = 4388.00, Z = -1.118, P = 0.264). The nonparametric Kruskall-Wallis test showed no significant difference in all age groups ({chi}{sup 2} = 13.466, P = 0.062). There was a slight negative correlation between the thyroid volume and age (r{sub s} = -0.166, P = 0.019). Conclusion: The accuracy and reliability of multi-slice spiral CT in measuring thyroid volume are very high. The thyroid volumes are not significantly difference between genders or among decades for the healthy, non-iodine-deficient adult population in southwestern region of China.

Spiral CT during pharmacoangiography with angiotensin II in patients with pancreatic disease. Technique and diagnostic efficacy

Energy Technology Data Exchange (ETDEWEB)

Kuroda, C.; Mihara, N.; Hosomi, N.; Inoue, E.; Fujita, M. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Diagnostic Radiology; Ohigashi, H.; Ishikawa, O. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Surgery; Nakaizumi, A. [Osaka Medical Center for Cancer and Cardiovascular Deseases (Japan). Dept. of Internal Medicine; Ishiguro, S. [Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan). Dept. of Pathology

1998-03-01

Purpose: To compare the diagnostic efficacy of pancreatic pharmacoangiographic CT using angiotensin II with conventional angiographic CT. Material and Methods: Eighteen patients with space-occupying pancreatic disease were examined in this study. Pharmacoangiographic CT was performed with a 1-3-{mu}/6-ml solution of angiotensin II injected through a catheter into the celiac artery during spiral CT. Results: In 17 of the 18 (94%) patients, the area of pancreatic parenchymal enhancement was the same or larger at pharmacoangiographic CT than at conventional angiographic CT. The attenuation value of the pancreatic parenchyma was significantly increased at pharmacoangiographic CT (p=0.0010). Although the attenuation value of tumors was also increased on images obtained after the injection of angiotensin II, the tumor-to-pancreas contrast was significantly greater at pharmacoangiographic CT (p=0.0479). The mean differences in attenuation between tumor and pancreas at angiographic CT with and without angiotensin II were respectively 182 HU and 115 HU. Conclusion: Pharmacoangiographic CT with angiotensin II proved superior to conventional angiographic CT in the diagnosis of pancreatic disease. We therefore recommend it as a supplementary technique at the angiographic examination of patients with suspected pancreatic tumor. (orig.).

Coronary artery stent imaging with 128-slice dual-source CT using high-pitch spiral acquisition in a cardiac phantom: comparison with the sequential and low-pitch spiral mode

International Nuclear Information System (INIS)

Wolf, Florian; Loewe, Christian; Plank, Christina; Schernthaner, Ruediger; Bercaczy, Dominik; Lammer, Johannes; Leschka, Sebastian; Goetti, Robert; Marincek, Borut; Alkadhi, Hatem; Homolka, Peter; Friedrich, Guy; Feuchtner, Gudrun

2010-01-01

To evaluate coronary stents in vitro using 128-slice-dual-source computed tomography (CT). Twelve different coronary stents placed in a non-moving cardiac/chest phantom were examined by 128-slice dual-source CT using three CT protocols [high-pitch spiral (HPS), sequential (SEQ) and conventional spiral (SPIR)]. Artificial in-stent lumen narrowing (ALN), visible inner stent area (VIA), artificial in-stent lumen attenuation (ALA) in percent, image noise inside/outside the stent and CTDIvol were measured. Mean ALN was 46% for HPS, 44% for SEQ and 47% for SPIR without significant difference. Mean VIA was similar with 31% for HPS, 30% for SEQ and 33% for SPIR. Mean ALA was, at 5% for HPS, significantly lower compared with -11% for SPIR (p = 0.024), but not different from SEQ with -1%. Mean image noise was significantly higher for HPS compared with SEQ and SPIR inside and outside the stent (p < 0.001). CTDIvol was lower for HPS (5.17 mGy), compared with SEQ (9.02 mGy) and SPIR (55.97 mGy), respectively. The HPS mode of 128-slice dual-source CT yields fewer artefacts inside the stent lumen compared with SPIR and SEQ, but image noise is higher. ALN is still too high for routine stent evaluation in clinical practice. Radiation dose of the HPS mode is markedly (less than about tenfold) reduced. (orig.)

Influence of a small field-of-view size on the detection of coronary artery calcifications with MSCT: in vitro and in vivo study

International Nuclear Information System (INIS)

Mahnken, Andreas H.; Muehlenbruch, Georg; Das, Marco; Pohl, Saskia; Guenther, Rolf W.; Wildberger, Joachim E.; Koos, Ralf; Stanzel, Sven

2006-01-01

The purpose of this study is to asses the impact of small field-of-view (FOV) sizes on the detection of coronary artery calcifications using multislice-spiral computed tomography (MSCT). First, a static chest phantom containing calcium inserts was scanned 10 times using a standardized scan protocol. Secondly, 50 patients (28 male, 63.6±10.6 years) underwent cardiac MSCT using the same protocol. Images were reconstructed with three different FOV sizes (180 x 180, 220 x 220, 380 x 380 mm 2 ). Coronary calcium scoring and risk stratification were performed for each image series. In the phantom study, the Agatston score calculated with a FOV size of 180 x 180 mm 2 was 657.80±20.05. At a FOV of 220 x 220 mm 2 and 380 x 380 mm 2 , the corresponding values were 657.04±21.36 and 655.04±20.74, respectively. The corresponding values in the patient study were 541.65±869.87, 541.91±872.57 and 536.61±867.81. No statistically significant differences in the calcium score were found comparing different FOV sizes. Significantly more lesions (p=0.00149) were detected in the patient study. Comparing the different FOV sizes of 180 x 180 mm 2 and 220 x 220 mm 2 (380 x 380 mm 2 ), four (six) patients had to be assigned to different risk groups. The use of small FOV sizes resulted in an improved detection of coronary calcifications influencing the risk stratification for further cardiac events in MSCT coronary calcium scoring. (orig.)

The values of MSCT multi-planar reconstruction in the diagnosis of lumbar spondylolysis

International Nuclear Information System (INIS)

Tan Qixuan; Zhu Gangming; Qian Huirong; Zhong Sheng

2007-01-01

Objective: To study the reasonable schedule and diagnostic values of MSCT multi-planar reconstruction in patients with lumbar spondylolysis. Methods: Volume scan ranging from T12 to S1 was done in 540 cases suffered from backleg pain without definite trauma. The lumbar disc axial and whole lumbar axial, sagital, coronal images were reconstructed from raw data of MSCT. Results: Of the 540 cases, 54 spondylolysis in isthmus of lumbar pedicle were demonstrated in 29 ones (29/540, 5.37%). 20 cases were accompanied with spondylolisthesis. The sagital multi-planar reconstruction was the best way to reveal the fissures of spondylolysis and accompanying abnormalities. The detectable ratio of fissures in lumbar disc with axial, whole lumbar axial, sagital and coronal multi-planer reconstruction images were 7.41%, 100%, 100% and 51.85% respectively. Conclusions: MSCT sagital multi-planar reconstruction is the best images to reveal the fissures of spondylolysis. It should be taken as routine item in MSCT examination for the patients with lower back pain. (authors)

Feasibility study of automatic tube current modulation in low-dose thoracic imaging for young children with 64-slice spiral CT

International Nuclear Information System (INIS)

Peng Yun; Li Jianyin; Zhang Qifeng; Liu Yue; Wang Bei; Zheng Jinjin

2008-01-01

Objective: To assess the feasibility of using an automatic tube current modulation (ATCM) method to obtain consistent image quality with reduced radiation dose for young children undergoing chest scans with a set of 64-slice spiral CT. Methods: Fifty young children underwent chest scans on a GE 64-slice VCT with automatic tube current modulation. The noise index (NI) for this study group was set to 8 or 9 based on the proposed reference for pediatric chest imaging in our hospital. We compared image quality and radiation dose for the study group with the age-matched control group of 50 young children acquired with standard protocol of fixed-mAs (120 and 150 mAs for under 1 and above 1 year old, respectively). The volume CT dose index(CTDIvol) values were recorded for both groups. Two experienced pediatric radiologists assessed image quality on a 5-point scale with 5 being the best. Scores greater than or equal to 3 were considered clinically acceptable. The degree of interobserver concordance was determined by Kappa statistics. Results: The average objective image noise and CTDIvol for control group was (4.78±0.58) and (6.68±0.62) mGy, respectively. For the study group the mean value of objective mAs was (41.6±11.6) (20-79 mAs) with mean CTDIvol of (2.34±0.71) mGy, and the use of ATCM produced mean noise of (7.84±0.66). The average CTDIvol with the use of NI of 8-9 was about 65% lower than that with the fixed mAs setting. The mean image quality score for the study group and control group was (3.46±0.40) and (4.65±0.46) respectively. All studies had acceptable image quality, and there was good inter-observer agreement in diagnostic acceptability (Kappa=0.474 and 0.536). Conclusion: The automatic tube current modulation method could be used to obtain consistent image quality for young children undergoing 64-slice MSCT chest scans. With proper noise level setting (NI=8 or 9), one may obtain clinically acceptable images with much reduced radiation dose. (authors)

The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography; Die Rolle der Ganzkoerper-Spiral-CT bei der Primaerdiagnostik polytraumatisierter Patienten - Vergleich mit konventioneller Radiographie und Abdomensonographie

Energy Technology Data Exchange (ETDEWEB)

Albrecht, T.; Schlippenbach, J. von; Wolf, K.J. [Klinik und Poliklinik fuer Radiologie und Nuklearmedizin, Charite - Campus Benjamin Franklin (Germany); Stahel, P.F.; Ertel, W. [Klinik fuer Unfall- und Wiederherstellungschirurgie, Charite - Campus Benjamin Franklin (Germany)

2004-08-01

Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

Induced pneumoperitoneum in spiral CT evaluation of gastric cancer

International Nuclear Information System (INIS)

Guo Hua; Gao Jianbo; Li Yintai; Yang Xuehua; Chen Xuejun; Guan Sheng

2001-01-01

Objective: To evaluate the diagnostic value and clinical significance of preoperative staging in gastric cancer with induced pneumoperitoneum in spiral CT (SCTPP). Methods: Both routine SCT and SCTPP were performed in 52 lean patients suffered from gastric cancers, and comparison was made between SCT findings and surgical and histopathologic findings. Results: The accuracy of routine SCT and SCTPP in determining the T-staging was 72% and 96%, respectively (x 2 = 8.0, P 2 = 0.006, P > 0.05). The sensitivity in determining M-staging was 61% and 100%, respectively (x 2 = 0.04, P 2 6.03, P < 0.05). Conclusion: The accuracy of SCTPP in determining preoperative staging of gastric cancer was significantly higher than that of routine SCT. SCTPP has important guiding significance for the selection of the treatment strategy in gastric cancer

Characterization of liver lesions with mangafodipir trisodium-enhanced MR imaging: multicenter study comparing MR and dual-phase spiral CT

NARCIS (Netherlands)

M. Oudkerk (Matthijs); C.G. Torres; B. Song; M. Konig; J. Grimm; J. Fernandez-Cuadrado; B. op de Beeck; M. Marquardt; P. van Dijk (Pieter); J.C. de Groot (Jan Cees)

2002-01-01

textabstractPURPOSE: To evaluate whether mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance (MR) imaging surpasses dual-phase spiral computed tomography (CT) in differentiating focal liver lesions. MATERIALS AND METHODS: One hundred forty-five patients who had or were

Measurements of computed tomography dose index for axial and spiral CT scanners

International Nuclear Information System (INIS)

Breiki, G; Abbas, Y.; Diab, H.M.; Gomaa, M

2007-01-01

The energy deposited in the patient by the rotating x-ray beam in computed tomography produces more uniform absorbed dose values within the section of imaged tissue than those produced in conventional radiological procedures. The dose values within a specific section are determined by factors such as voltage, current, scan field, rotation angle, filtration, collimation, and section thickness and spacing. This study is a part of extensive project, aiming to investigate practice of computed tomography at various hospitals and to implement a Reference Dose Levels (RDLs) to routine CT examinations in Egypt. The dosimetric quantities proposed in the European Guidelines (EG) for CT are weighted computed tomography dose index (CTDI w ) for a single slice and dose-length product (DLP) for a complete examination. Patient-related data as well as technical parameters for head, chest, abdomen and pelvis examinations were collected for seven CT scanners in public and private hospitals.Dose measurements were performed for both axial and spiral models for a range of CT examinations using CT dosimetry head and body phantoms, and ion chamber designed for CT dosimetry. The determined CTDI w and DLP values were compared with the European Commission reference dose levels (ECRDLs) and also with some international survey results. Mean values of CTDI w had a range of 36-69 m Gy with average 55 m Gy for head, and 11-35 mGy with average 23 mGy for chest, abdomen and pelvis examinations. The current reference CTDI w values are 60 m Gy for adult head and 25 m Gy for adult Abdomen

Left coronary to right ventricle fistula in a child: management strategy based on cardiac-gated 64-slice CT

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Marini, Davide; Agnoletti, Gabriella; Bonnet, Damien [University Rene Descartes-Paris V, Department of Paediatric Cardiology, Hopital Necker-Enfants Malades, AP-HP, Paris (France); Brunelle, Francis; Ou, Phalla [University Rene Descartes-Paris V, Department of Paediatric Radiology, Hopital Necker-Enfants Malades, AP-HP, Paris (France)

2008-03-15

Congenital coronary fistulae are a diagnostic challenge. A prerequisite for best management is accurate anatomical evaluation, traditionally provided by invasive catheter angiography. Multislice CT (MSCT) is an emerging noninvasive technique for coronary artery evaluation. We present a 3-year-old boy and highlight the clinical usefulness of new-generation MSCT to study coronary artery fistulae in children. Multiplanar and 3-D reconstruction offer invaluable information to plan the best therapeutic strategy in this setting. We provide evidence for the expanding clinical role of MSCT for coronary artery imaging in children. (orig.)

Left coronary to right ventricle fistula in a child: management strategy based on cardiac-gated 64-slice CT

International Nuclear Information System (INIS)

Marini, Davide; Agnoletti, Gabriella; Bonnet, Damien; Brunelle, Francis; Ou, Phalla

2008-01-01

Congenital coronary fistulae are a diagnostic challenge. A prerequisite for best management is accurate anatomical evaluation, traditionally provided by invasive catheter angiography. Multislice CT (MSCT) is an emerging noninvasive technique for coronary artery evaluation. We present a 3-year-old boy and highlight the clinical usefulness of new-generation MSCT to study coronary artery fistulae in children. Multiplanar and 3-D reconstruction offer invaluable information to plan the best therapeutic strategy in this setting. We provide evidence for the expanding clinical role of MSCT for coronary artery imaging in children. (orig.)

Prevalence of emphysematous changes as shown by low-dose spiral CT screening images in 6144 healthy subjects

International Nuclear Information System (INIS)

Nawa, Takeshi

2002-01-01

We assessed the prevalence of emphysematous changes among healthy workers and retired persons, using subjective evaluations of low-dose spiral CT images obtained during thoracic CT screenings for lung cancer. Among 6144 male participants (50-69 years old; mean age, 57), we detected 686 cases (11.2%) with emphysematous changes. The majority (95.3%) of CT-detected emphysema cases were in current or former smokers, and 169 cases (24.6%) showed significant obstructive impairment. Of 236 cases with emphysematous changes in the internal region (more than 20 mm from the costal margin), 98 (41.5%) had significant obstructive impairment. Smoking was found to be the major risk factor for CT-detected emphysema. Longitudinal observation of the emphysema cases, as well as health care support for cessation of smoking, is very important. (author)

Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT

International Nuclear Information System (INIS)

Picozzi, Giulia; Paci, Enrico; Lopes Pegna, Andrea

2005-01-01

Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64±4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was [it

CT coronary angiography: examination technique, clinical results, and outlook on future developments

International Nuclear Information System (INIS)

Dewey, M.; Hamm, B.

2007-01-01

Multislice computed tomography (MSCT) after intravenous contrast agent administration enables visualization of the coronary arteries with high spatial resolution (voxel sizes down to 0.5 x 0.35 x 0.35 mm3) and a short scan time. Magnetic resonance imaging (MRI) is also intensively studied with respect to the noninvasive detection of coronary artery stenosis and thus the detection of coronary artery disease (CAD) without radiation exposure but is not equal to MSCT at present. This article provides an overview of the historical development of CT coronary angiography from 4-slice CT to 16-slice CT and 64-slice CT. A crucial aspect of this development is the improvement in image quality resulting from shorter breath-hold periods and the reduced gantry rotation time. Other techniques that appear to considerably improve image quality and accuracy and make CT independent of patient heart rates are multisegment reconstruction and dual-source CT. Sublingual nitroglycerin as well as oral or intravenous betablocker administration should be considered in relation to the diagnostic question to be answered and the patient's heart rate. In the studies available CT coronary angiography with at least 12 simultaneous detector rows has a sensitivity of 96.9 % and a specificity of 75.3 % at the patient level. Especially the negative predictive value of CT (94.6 %) emphasizes the idea that this technique may reliably exclude CAD in patients with intermediate pretest likelihood. In the near future, 256-slice CT will allow examination of the entire heart during one heartbeat or even 4D CT scanning with simultaneous assessment of myocardial perfusion. Automatic or semiautomatic software tools will assume a central place in detecting and quantifying coronary artery stenoses and plaques as well as in the analysis of cardiac function in the clinical setting over the next years. Prior to its routine clinical use, the cost-effectiveness of CT coronary angiography must be determined and the

Multi-slice CT (MSCT) in cardiac function imaging: threshold-value-supported 3D volume reconstructions to determine the left ventricular ejection fraction in comparison to MRI

International Nuclear Information System (INIS)

Ehrhard, K.; Oberholzer, K.; Gast, K.; Mildenberger, P.; Kreitner, K.F.; Thelen, M.

2002-01-01

Purpose: To assess MSCT of the heart to determining left ventricular ejection fraction (EF) based on threshold-value-supported 3D volume reconstructions compared to MRI. Methods: Cardiac MSCT was performed in 7 patients. Images were reconstructed during end-systolic and end-diastolic phases of the cardiac cycle and transformed to 3D volumes to determine end-systolic (ESV) and end-diastolic volume (EDV) by using different lower threshold values: besides fixed lower threshold values, identical for each image sequence, individual lower threshold values dependent on contrast enhancement of the left ventricle were applied. The latter represent the mean value calculated by combining the average CT-density of the myocardium and the contrast-enhanced blood in the left ventricle. The EF derived from ESV and EDV. Results: The best correlation with MR imaging was obtained for ESV and EDV by using the individual lower threshold values for the respective sequence. The correlation coefficient for ESV was 0.95 and for EDV it was 0.93. On average, the ESV was overestimated by 3.72 ml, while the ESD was underestimated by 2.85 ml. The respective standard deviation for the ESV was 14,87 ml, for the EDV it was 26.83 ml. On average, the EF was underestimated by 3.57% with a standard deviation of 9.43% and a correlation coefficient of 0.83 in comparison to MRI. Conclusion: The threshold-value-supported 3D volume reconstruction of the left ventricle represents a good method to determine the left ventricular function parameters. Due to the differences in the contrast enhancement, the use of an individual lower threshold value for every image sequence is of particular importance. (orig.) [de

Clinical application of MSCT in the diagnosis of anomalous pulmonary venous connection in infants and children

International Nuclear Information System (INIS)

Huang Meiping; Liang Changhong; Zeng Hui; Liu Qishun; Zhang Zhonglin; Zhang Jin'e; Huang Biao

2005-01-01

Objective: To investigate the clinical usefulness of multislice computed tomography (MSCT) in the diagnosis of anomalous pulmonary venous connection in infants and children. Methods: Retrospective analysis on 20 cases with anomalous pulmonary venous connection was performed using contrast-enhanced MSCT volume scan. The age ranged from 11 days to 12 years. The slice thickness and slice interval were 1.250 mm and 0.625 mm, respectively. Three-dimensional reconstructions were performed with multiplanar reformation (MPR), sliding thin-slabmaximum intensity projection (STS-MIP), volume rendering (VR), and shade-surface displayment (SSD). Ultrasound echocardiography (US) was performed in all patients. Conventional cardiovascular angiography (CAG) was performed in 12 patients, and 14 cased received operation. Results: Of the 20 patients received MSCT, total anomalous pulmonary venous connection was diagnosed in 9, and partial anomalous pulmonary venous connection in 11, including supracardiac type (n=5), cardiac type (n=10), infracardiac type (n=4), and mixed type (n=1). MSCT clearly displayed the number, distribution, and location of anomalous pulmonary venous connection in all patients. Among them, the misdiagnosis by CAG and US were encountered in 3 cases and 10 cases, respectively. The diagnosis by MSCT was compatible with the operative findings in all 14 patients receiving surgery. Conclusion: MSCT has significant value in the diagnosis of pediatric anomalous pulmonary venous connection which may not be detectable with echocardiography or even cardiovascular angiography. (authors)

Dual source multidetector CT-angiography before transcatheter aortic valve implantation (TAVI) using a high-pitch spiral acquisition mode

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Wuest, W.; Anders, K.; May, M.S.; Uder, M. [University of Erlangen, Department of Radiology, Erlangen (Germany); Schuhbaeck, A.; Gauss, S.; Marwan, M.; Arnold, M.; Muschiol, G.; Daniel, W.G.; Achenbach, S. [University of Erlangen, Department of Cardiology, Erlangen (Germany); Ensminger, S. [University of Erlangen, Department of Cardiac Surgery, Erlangen (Germany)

2012-01-15

Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access. 42 patients (82 {+-} 6 years) scheduled for TAVI underwent dual source (DS) CT angiography (CTA) of the aorta using a prospectively ECG-triggered high-pitch spiral mode (pitch = 3.4) with 40 mL iodinated contrast agent. We analyzed aortic root/iliac dimensions, attenuation, contrast to noise ratio (CNR), image noise and radiation exposure. Aortic root/iliac dimensions and distance of coronary ostia from the annulus could be determined in all cases. Mean aortic and iliac artery attenuation was 320 {+-} 70 HU and 340 {+-} 77 HU. Aortic/iliac CNR was 21.7 {+-} 6.8 HU and 14.5 {+-} 5.4 HU using 100 kV (18.8 {+-} 4.1 HU and 8.7 {+-} 2.6 HU using 120 kV). Mean effective dose was 4.5 {+-} 1.2 mSv. High-pitch spiral DSCTA can be used to assess the entire aorta and iliac arteries in TAVI candidates with a low volume of contrast agent while preserving diagnostic image quality. (orig.)

Spiral hydro-CT of the pancreas in the thin-slice method; Hydrospiral-CT des Pankreas in Duennschichttechnik

Energy Technology Data Exchange (ETDEWEB)

Richter, G.M. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); Simon, C. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany)]|[Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Hoffmann, V. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); DeBernardinis, M. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany); Seelos, R. [Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Senninger, N. [Abt. Allgemeine Chirurgie, Chirurgische Universitaetsklinik Heidelberg (Germany); Kauffmann, G.W. [Abt. fuer Radiodiagnostik, Radiologische Universitaetsklinik Heidelberg (Germany)

1996-05-01

In an open prospective study, 151 patients with a suspected pancreatic neoplasm based on clinical, laboratory or other imaging data were examined between May 94 and October 95. Our newly developed Hydro-CT methodology included intravenous injection of 40 mg N-butylscopolaminium bromide (Buscopan) for intestinal paralysis, gastric and duodenal wall distension by oral administration of an average of 1.5 l warm tap water, 30 RAO patient positioning, an individualized contrast injection technique as determined beforehand by time-to-peak measurement in the portal vein and thin-slice spiral CT (3 mm increment, 6 mm table feed and 3 mm secondary reconstruction). A detailed evaluation form was used to assess (1) tumor detection rate, (2) differentiation of malignant versus benign disease, (3) differential diagnosis, and (4) accuracy of assessment of resectability by identification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, portal vein and celiac trunk, superior mesenteric, splenic and hepatic arteries. As the gold standard for positive tumor detection surgery and microscopic diagnosis were used, and for negative tumor detection an event-free survival of 6 months. Almost all examinations were well tolerated. In only 4% was on-site administration of a gastric tube required because of vomiting. In 2% of the patients a slight allergic reaction to be contrast medium was seen. The prevalence of a pancreatic neoplasm was 38%. In tumor detection Hydro-CT reached an overall accuracy of 97.4% with a sensitivity of 100% and a specificity of 95.9%. In the differentiation of benign versus malignant disease Hydro-CT reached an overall accuracy of 89.7% with a sensitivity of 92.5% and a specificity of 83.3%. The prevalence of a pancreatic carcinoma was 24%; 4% other malignant tumors were found (distal common bile duct carcinoma, cystadenocarcinoma). (orig./MG) [Deutsch] Von Mai 1994 bis Oktober 1995 wurden

Negative spiral CT in acute pulmonary embolism

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Nilsson, T.; Olausson, A. [Karolinska Hospital, Stockholm (Sweden). Dept. of Thoracic Radiology; Johnsson, H. [Karolinska Hospital, Stockholm (Sweden). Dept. of Internal Medicine; Nyman, U. [County Hospital, Trelleborg (Sweden). Dept. of Radiology; Aspelin, P. [Huddinge Univ. Hospital (Sweden). Dept. of Radiology

2002-09-01

Purpose: To retrospectively evaluate the clinical outcome of non-anticoagulated patients with clinically suspected acute pulmonary embolism (PE) and no symptoms or signs of deep venous thrombosis (DVT) following a negative contrast medium-enhanced spiral CT of the pulmonary arteries (s-CTPA). Material and Methods: During a 24-month period, 739 of 751 patients underwent s-CTPA with acceptable diagnostic quality for clinically suspected acute PE. All patients who had a CT study not positive for PE were followed up with a questionnaire, a telephone interview and review of all medical reports, including autopsies and death certificates for any episodes of venous thromboembolism (VTE) during a 3-month period. Results: PE was diagnosed in 158 patients. Of the remaining 581 patients with a negative s-CTPA, 45 patients were lost to follow-up. 88 patients were excluded because of anticoagulation treatment (cardiac disorder n=32, chronic VTE or acute symptomatic DVT n=31, PE diagnosed at pulmonary angiography n=1, thrombus prophylaxis during diagnostic work-up or other reasons than VTE n=24) and 7 patients undergoing lower extremity venous studies because of symptoms of DVT (all negative). Thus, 441 patients with a negative s-CTPA and no DVT symptoms, venous studies or anticoagulant treatment constituted the follow-up cohort. Four of these patients had proven VTE (all PE) during the 3-month follow-up period. Two of the PE episodes contributed to the patient's death. Conclusion: Patients with clinically suspected acute PE, no symptoms or signs of DVT and a negative single slice s-CTPA using 3-5 mm collimation, may safely be left without anticoagulation treatment unless they are critically ill, have a limited cardiopulmonary reserve and/or if a high clinical suspicion remains.

Dose reduction in spiral CT angiography of thoracic outlet syndrome by anatomically adapted tube current modulation

International Nuclear Information System (INIS)

Mastora, I.; Remy-Jardin, M.; Remy, J.; Suess, C.; Scherf, C.; Guillot, J.P.

2001-01-01

The aim of this study was to evaluate dose reduction in spiral CT angiography of the thoracic outlet by on-line tube-current control. Prospectively, 114 patients undergoing spiral CT angiography of the subclavian artery for thoracic outlet arterial syndromes were evaluated with and without tube-current modulation at the same session (scanning parameters for the two successive angiograms, one in the neutral position and one after the postural maneuver): 140 kV; 206 mA; scan time 0.75 s; collimation 3 mm; pitch = (1). The dose reduction system was applied in the neutral position in the first 92 consecutive patients and after postural maneuver in the remaining 22 consecutive patients. Dose reduction and image quality were analyzed in the overall study group (group 1; n = 114). The influence of the arm position was assessed in 44 of the 114 patients (group 2), matched by the transverse diameter of the upper thorax. The mean dose reduction was 33 % in group 1 (range 22-40 %) and 34 % in group 2 (range 26-40 %). In group 2 the only difference in image quality was a significantly higher frequency of graininess on low-dose scans compared with reference scans whatever the patient's arm position, graded as minimal in 38 of the 44 patients (86 %). When the low-dose technique was applied after postural maneuver in group 2: (a) the mean dose reduction was significantly higher (35 vs 32 % in the neutral position; p = 0.006); (b) graininess was less frequent (82 vs 91 % in the neutral position); and (c) the percentage of graininess graded as minimal was significantly higher (83 vs 70 % in the neutral position; p = 0.2027). On-line tube-current modulation enables dose reduction on high-quality, diagnostic spiral CT angiograms of the thoracic outlet and should be applied during data acquisition in the neutral position and after postural maneuver for optimal use. (orig.)

Dose reduction in spiral CT angiography of thoracic outlet syndrome by anatomically adapted tube current modulation

Energy Technology Data Exchange (ETDEWEB)

Mastora, I.; Remy-Jardin, M.; Remy, J. [Dept. of Radiology, University Center Hospital Calmette, Lille (France); Medical Research Group, Lille (France); Suess, C.; Scherf, C. [Siemens Medical Systems, Forcheim (Germany); Guillot, J.P. [Dept. of Radiology, University Center Hospital Calmette, Lille (France)

2001-04-01

The aim of this study was to evaluate dose reduction in spiral CT angiography of the thoracic outlet by on-line tube-current control. Prospectively, 114 patients undergoing spiral CT angiography of the subclavian artery for thoracic outlet arterial syndromes were evaluated with and without tube-current modulation at the same session (scanning parameters for the two successive angiograms, one in the neutral position and one after the postural maneuver): 140 kV; 206 mA; scan time 0.75 s; collimation 3 mm; pitch = (1). The dose reduction system was applied in the neutral position in the first 92 consecutive patients and after postural maneuver in the remaining 22 consecutive patients. Dose reduction and image quality were analyzed in the overall study group (group 1; n = 114). The influence of the arm position was assessed in 44 of the 114 patients (group 2), matched by the transverse diameter of the upper thorax. The mean dose reduction was 33 % in group 1 (range 22-40 %) and 34 % in group 2 (range 26-40 %). In group 2 the only difference in image quality was a significantly higher frequency of graininess on low-dose scans compared with reference scans whatever the patient's arm position, graded as minimal in 38 of the 44 patients (86 %). When the low-dose technique was applied after postural maneuver in group 2: (a) the mean dose reduction was significantly higher (35 vs 32 % in the neutral position; p = 0.006); (b) graininess was less frequent (82 vs 91 % in the neutral position); and (c) the percentage of graininess graded as minimal was significantly higher (83 vs 70 % in the neutral position; p = 0.2027). On-line tube-current modulation enables dose reduction on high-quality, diagnostic spiral CT angiograms of the thoracic outlet and should be applied during data acquisition in the neutral position and after postural maneuver for optimal use. (orig.)

Spiral computed tomography phase-space source model in the BEAMnrc/EGSnrc Monte Carlo system: implementation and validation

International Nuclear Information System (INIS)

Kim, Sangroh; Yoshizumi, Terry T; Yin Fangfang; Chetty, Indrin J

2013-01-01

Currently, the BEAMnrc/EGSnrc Monte Carlo (MC) system does not provide a spiral CT source model for the simulation of spiral CT scanning. We developed and validated a spiral CT phase-space source model in the BEAMnrc/EGSnrc system. The spiral phase-space source model was implemented in the DOSXYZnrc user code of the BEAMnrc/EGSnrc system by analyzing the geometry of spiral CT scan—scan range, initial angle, rotational direction, pitch, slice thickness, etc. Table movement was simulated by changing the coordinates of the isocenter as a function of beam angles. Some parameters such as pitch, slice thickness and translation per rotation were also incorporated into the model to make the new phase-space source model, designed specifically for spiral CT scan simulations. The source model was hard-coded by modifying the ‘ISource = 8: Phase-Space Source Incident from Multiple Directions’ in the srcxyznrc.mortran and dosxyznrc.mortran files in the DOSXYZnrc user code. In order to verify the implementation, spiral CT scans were simulated in a CT dose index phantom using the validated x-ray tube model of a commercial CT simulator for both the original multi-direction source (ISOURCE = 8) and the new phase-space source model in the DOSXYZnrc system. Then the acquired 2D and 3D dose distributions were analyzed with respect to the input parameters for various pitch values. In addition, surface-dose profiles were also measured for a patient CT scan protocol using radiochromic film and were compared with the MC simulations. The new phase-space source model was found to simulate the spiral CT scanning in a single simulation run accurately. It also produced the equivalent dose distribution of the ISOURCE = 8 model for the same CT scan parameters. The MC-simulated surface profiles were well matched to the film measurement overall within 10%. The new spiral CT phase-space source model was implemented in the BEAMnrc/EGSnrc system. This work will be beneficial in estimating the

Spiral computed tomography phase-space source model in the BEAMnrc/EGSnrc Monte Carlo system: implementation and validation.

Science.gov (United States)

Kim, Sangroh; Yoshizumi, Terry T; Yin, Fang-Fang; Chetty, Indrin J

2013-04-21

Currently, the BEAMnrc/EGSnrc Monte Carlo (MC) system does not provide a spiral CT source model for the simulation of spiral CT scanning. We developed and validated a spiral CT phase-space source model in the BEAMnrc/EGSnrc system. The spiral phase-space source model was implemented in the DOSXYZnrc user code of the BEAMnrc/EGSnrc system by analyzing the geometry of spiral CT scan-scan range, initial angle, rotational direction, pitch, slice thickness, etc. Table movement was simulated by changing the coordinates of the isocenter as a function of beam angles. Some parameters such as pitch, slice thickness and translation per rotation were also incorporated into the model to make the new phase-space source model, designed specifically for spiral CT scan simulations. The source model was hard-coded by modifying the 'ISource = 8: Phase-Space Source Incident from Multiple Directions' in the srcxyznrc.mortran and dosxyznrc.mortran files in the DOSXYZnrc user code. In order to verify the implementation, spiral CT scans were simulated in a CT dose index phantom using the validated x-ray tube model of a commercial CT simulator for both the original multi-direction source (ISOURCE = 8) and the new phase-space source model in the DOSXYZnrc system. Then the acquired 2D and 3D dose distributions were analyzed with respect to the input parameters for various pitch values. In addition, surface-dose profiles were also measured for a patient CT scan protocol using radiochromic film and were compared with the MC simulations. The new phase-space source model was found to simulate the spiral CT scanning in a single simulation run accurately. It also produced the equivalent dose distribution of the ISOURCE = 8 model for the same CT scan parameters. The MC-simulated surface profiles were well matched to the film measurement overall within 10%. The new spiral CT phase-space source model was implemented in the BEAMnrc/EGSnrc system. This work will be beneficial in estimating the spiral

Assessment of the right ventricular function in patients with chronic obstructive pulmonary disease and cor pulmonale using cardiac 64-slice spiral CT comparing with 1.7 T MRI

International Nuclear Information System (INIS)

Gao Yan; Li Kuncheng; Du Xiangying; Liang Lei; Cao Lizhen; Li Yan; Zhao Shen; Guo Ying

2009-01-01

function on cardiac CT were correlated well with that on cardiac MRI. The MM of the RV showed moderate correlation (r=0.82), RV volumes and RVEF significant correlation (r=0.98 and 0.97 for RV EDV and RV ESV, r=0.95 for RVEF, respectively). A strong correlation between MSCT and MRI for the assessment of RV function was also found using Bland-Altman plot. The correlation was excellent between the MSCT results and forced expiratory volume in 1 sec (r=0.781 for RVEF, r=-0.824 for RV MM) in COPD patients. Conclusions: Cardiac MSCT can accurately assess the RV size and function in comparison to MRL Patients with severe COPD have RV dysfunction. (authors)

Multi-slice CT three dimensional volume measurement of tumors and livers in hepatocellular carcinoma

International Nuclear Information System (INIS)

Yu Yuanlong; Li Liangcai; Tang Binghang; Hu Zemin

2004-01-01

Objective: To examine the accuracy of multi-slice CT (MSCT) three dimensional (3D) volume measurement of tumors and livers in hepatocellular carcinoma cases by using immersion method as the standard. Methods: (1) The volume of 25 porkling livers was measured using immersion method in experiment group in vitro. Then the models were built according to Matsumoto's method and CT scanning and special software were used to measure the volume of the livers. (2) The volume of the tumors in 25 cases of hepatocellular carcinoma was measured using diameter measurement method and special volume measurement software (tissue measurements). Two tumors of them were measured respectively using MSCT 3D measurement, diameter measurement before the operation and immersion method after the operation. The data of the two groups were examined using pairing t test. Results: (1) The volume range of 25 porkling livers was 68.50-1150.10 ml using immersion method and 69.78-1069.97 ml using MSCT 3D measurement. There was no significant difference of the data in these two groups using t-test (t=1.427, P>0.05). (2) The volume range of 25 hepatocellular tumors was 395.16-2747.7 ml using diameter measurement and 203.10-1463.19 ml using MSCT 3D measurement before the operation. There was significant difference of the data in these two groups using t-test (t=7.689, P<0.001). In 2 ablated tumors, 1 case's volume was (21.75±0.60) ml using MSCT 3D measurement and 33.73 ml using diameter measurement before the operation and 21.50 ml using immersion measurement after the operation. The other case's volume was (696.13±5.30) ml using MSCT 3D measurement and 1323.51 ml using diameter measurement before the operation and 685.50 ml using immersion measurement after the operation. Conclusion: MSCT 3D volume measurement can accurately measure the volume of tumor and liver and has important clinical application value. There is no significant difference between MSCT 3D volume measurement and immersion method

Correlation between spiral CT features of pericolic infiltration and tumor angiogenesis in colorectal carcinoma

International Nuclear Information System (INIS)

Zhang Ruiping; Li Jianding

2007-01-01

Objective: To investigate the correlation of spiral CT (SCT) features with pathology, microvessel density (MVD), expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2( MMP-2) in colorectal carcinoma. Methods: Forty patients with colorectal carcinoma confirmed by operation were examined by SCT. The resected tumor specimens were immunohistochemically stained for the expression of VEGF, MMP-2 and the calculation of MVD. Results: The accuracy of SCT in depicting the pericolic and wall infiltration was 92.5%. The metastasis rates of colorectal cancer with pericolic infiltration and wall infiltration were 75.0% and 33.3%, respectively, the differences were statistically significant between the two groups (P<0.05). The differences of CT enhancement value, MVD, expressions of VEGF and MMP-2 between the two groups were statistically significant (P<0.05). The enhancement degree of CT had a positive correlation with MVD (P<0.05). Conclusion: SCT is accurate for depicting pericolic and wall infiltration, pericolic infiltration in colorectal carcinoma indicates the tendency of metastasis. The enhancement degree of CT might be used to quantitatively evaluate the tumor angiogenesis, expressions of VEGF and MMP-2 and MVD are closely correlated with the infiltration of colorectal cancer. (authors)

Use of spiral CT and the contrast medium iohexol to determine in one session aortorenal morphology and the relative glomerular filtration rate of each kidney

International Nuclear Information System (INIS)

Frennby, B.; Almen, T.

2001-01-01

The aim of this study was to determine the relative glomerular filtration rate (GFR), i.e. the GFR of each kidney in percent of total GFR, by spiral CT. In 41 patients, who were part of a follow-up program after endoluminal stent grafting of aortic aneurysm, spiral CT with the contrast medium iohexol was used to evaluate the morphology of the aorta and kidneys. The opportunity was taken to utilize the already injected iohexol to determine the relative GFR with an extra CT sequence. In each patient two determinations were made, 6 or 12 months apart. The amount of a GFR marker accumulating in Bowman's space, tubuli, and renal pelvis within 2-3 min after i.v. injection, before any marker had left the kidney via the ureter, was defined as proportional to the GFR of that kidney. The renal accumulation of iohexol was obtained by spiral CT using 10-mm collimation and a table speed of 10 mm/s (pitch ratio 1:1) from the upper to the lower poles. The correlation coefficient between the relative GFR of each kidney determined at the first and second examination was excellent (r=0.99) with a median (range) difference of 1% (0-6%) of total GFR. The radiation dose calculated as the mean absorbed dose to the kidneys was 50 mGy and the effective dose 5 mSv. The morphology of aorta and kidneys and the relative GFR of each kidney can be determined in one session with spiral CT using iohexol as both angiographic contrast medium and as a GFR marker. It is also possible to take some plasma samples in the same session to determine iohexol concentration to calculate the body clearance of iohexol (or take plasma and urine samples to calculate the renal clearance of iohexol). (orig.)

Quantitative assessment of pulmonary function using low dose multi-slice spiral CT in smoker

International Nuclear Information System (INIS)

Chen Huai; Zeng Qingsi; Zheng Jinping; Guan Yubao; Zhang Chaoliang; Cen Renli

2012-01-01

Objective: To evaluate the clinical feasibility of low dose MSCT for quantitative assessment of pulmonary function in smokers. Methods: One hundred and forty-six patients with chronic objective pulmonary disease (COPD) including 109 smokers (74.6%) and 37 non-smokers (25.3%) underwent pulmonary function test and low-dose MSCT scan. All data were analyzed using computer-aided lung analysis software. Pulmonary function parameters from low-dose MSCT were compared between smokers and non-smokers and also compared with pulmonary function test in non-smokers (Pearson test). Results: In smokers, the average volume at full inspiratory phase (Vin) was (5125 ± 862 ) ml, mean lung attenuation was (-902 ± 26) HU, mean lung density was (0.0984 ± 0.0260 ) g/cm 3 , emphysema volume was (2890 ±1370) ml. The average volume at full expiratory phase (Vex) was (2756 ±1027) ml, mean lung attenuation was (-811 ±62) HU, mean lung density was (0.1878 ±0.0631) g/cm 3 , emphysema volume was (685 ±104) ml. In non-smokers, the average Vin was (3734 ± 759) ml, mean lung attenuation was (-876 ±40) HU,mean lung density was (0.1244 ±0.0401)g/cm 3 , emphysema volume was ( 1503 ± 1217) ml. The average Vex was (1770 ± 679) ml, mean lung attenuation was (-765 ± 56) HU, mean lung density was (0.2360 ± 0.0563) g/cm 3 , emphysema volume was (156 ± 45) ml. There were significant differences between smokers and non-smokers (P<0.01). The Vex/Vin was correlated with residual volume/total lung capacity (RV/TLC, r=0.60, P<0.01), and Vin was correlated with TLC (r=0.58, P<0.01), Vex with RV (r=0.59, P<0.01). Pixel index (PI) -950 in was correlated with FEV 1% pre and FEV1/FVC% (r=-0.53, -0.62, respective, P<0.01), Pl-950ex was correlated with FEV1 % pre and FEV1/FVC% (r=-0.71, -0.77, respective, P<0.01). Conclusion: Low-dose MSCT can be a potential imaging tool for quantitative pulmonary function assessment in smokes. (authors)

The Role of Spiral Multidetector Dynamic CT in the Study of Williams-Campbell Syndrome

International Nuclear Information System (INIS)

Scioscio, V. di; Zompatori, M.; Mistura, I.; Montanari, P.; Santilli, L.; Luccaroni, R.; Sverzellati, N.

2006-01-01

Williams-Campbell syndrome is a cystic bronchiectatic disease secondary to deficiency or defect of cartilaginous plates in the wall of the airways. In the literature, two main forms are suggested: congenital and acquired (post-infectious). The most frequent symptoms are represented by recurrent pulmonary infections from childhood. Multislice spiral dynamic CT has a major role in the study of cystic pulmonary disease and in differentiating Williams-Campbell syndrome from the other causes of cystic bronchiectasis, in which even lung function tests can give deceptive results

The Role of Spiral Multidetector Dynamic CT in the Study of Williams-Campbell Syndrome

Energy Technology Data Exchange (ETDEWEB)

Scioscio, V. di; Zompatori, M.; Mistura, I.; Montanari, P.; Santilli, L.; Luccaroni, R.; Sverzellati, N. [Medical Univ. of Bologna, S. Orsola-Malpighi Policlinic (Italy). Dept. of Radiology

2006-10-15

Williams-Campbell syndrome is a cystic bronchiectatic disease secondary to deficiency or defect of cartilaginous plates in the wall of the airways. In the literature, two main forms are suggested: congenital and acquired (post-infectious). The most frequent symptoms are represented by recurrent pulmonary infections from childhood. Multislice spiral dynamic CT has a major role in the study of cystic pulmonary disease and in differentiating Williams-Campbell syndrome from the other causes of cystic bronchiectasis, in which even lung function tests can give deceptive results.

Multi-slice spiral CT in the diagnosis of congenital heart diseases associated with tracheobronchial stenosis in children

International Nuclear Information System (INIS)

Wang Rongpin; Liang Changhong; Huang Meiping; Liu Hui; Cui Yanhai; Liu Qishun

2010-01-01

Objective: To explore the diagnostic value of post processing techniques of MSCT for diagnosing congenital heart disease associated with tracheobronchial stenosis in children. Methods: Thirty four patients with congenital heart disease complicated by tracheobronchial stenosis were evaluated with MSCT. MPR, CPR, MinIP and VR were performed to show the tracheobronchial morphology. Findings in 43 segments of 32 cases were compared with the findings of surgical operation. Mann-Whitney test was employed to assess the significance of measurement between the post processing techniques and the operation. Results: The length of stenotic segments were variable seen at operation, with values between 4- 39 mm in trachea, 4-33 mm in main bronchi and 3-12 mm in lobe bronchi, respectively. The biggest difference between the measurement of operation and MSCT was 4 mm (3 segments). Other differences of stenotic segments were within 3 mm. Six segments exhibited mild, 16 moderate and 21 severe stenosis at surgery. By contrast, five segments exhibited mild, 17 moderate and 21 severe stenosis by MPR or CPR, 2 mild, 9 moderate and 32 severe stenosis by MinIP and 4 mild, 11 moderate and 28 sever stenosis by VR, respectively. There was no significant difference in measuring the degree of tracheobronchial stenosis between MPR or CPR, VR and the surgery (Z=-0.105, -1.479; P>0.05), while MinIP frequently overrated the degree of stenosis compared with the measurement at surgery (Z=-2.484, P=0.013). Conclusion: The integrated three dimensional reformations of MSCT scan can accurately evaluate the degree and extent of congenital heart disease associated with tracheobronchial stenosis in children and provide valuable information for clinical management. (authors)

Pictorial review: Electron beam computed tomography and multislice spiral computed tomography for cardiac imaging

International Nuclear Information System (INIS)

Lembcke, Alexander; Hein, Patrick A.; Dohmen, Pascal M.; Klessen, Christian; Wiese, Till H.; Hoffmann, Udo; Hamm, Bernd; Enzweiler, Christian N.H.

2006-01-01

Electron beam computed tomography (EBCT) revolutionized cardiac imaging by combining a constant high temporal resolution with prospective ECG triggering. For years, EBCT was the primary technique for some non-invasive diagnostic cardiac procedures such as calcium scoring and non-invasive angiography of the coronary arteries. Multislice spiral computed tomography (MSCT) on the other hand significantly advanced cardiac imaging through high volume coverage, improved spatial resolution and retrospective ECG gating. This pictorial review will illustrate the basic differences between both modalities with special emphasis to their image quality. Several experimental and clinical examples demonstrate the strengths and limitations of both imaging modalities in an intraindividual comparison for a broad range of diagnostic applications such as coronary artery calcium scoring, coronary angiography including stent visualization as well as functional assessment of the cardiac ventricles and valves. In general, our examples indicate that EBCT suffers from a number of shortcomings such as limited spatial resolution and a low contrast-to-noise ratio. Thus, EBCT should now only be used in selected cases where a constant high temporal resolution is a crucial issue, such as dynamic (cine) imaging. Due to isotropic submillimeter spatial resolution and retrospective data selection MSCT seems to be the non-invasive method of choice for cardiac imaging in general, and for assessment of the coronary arteries in particular. However, technical developments are still needed to further improve the temporal resolution in MSCT and to reduce the substantial radiation exposure

Diagnosis and staging of carcinoma localized in the antral part of the stomach with spiral CT

International Nuclear Information System (INIS)

Pomakov, P.; Grudeva, V.; Mlachkova, D.

2009-01-01

The aim of the study was to characterize CT images and stages of carcinomas localized in the antral part of the stomach obtained with spiral CT. Seven men aged from 54 years old to 81 years old inclusive, with subjective complaints and clinical suspicion of a neoplasm in the upper gastrointestinal tract were examine Examinations were performed following stomach wall re relaxation with Buscolysin.The stomach is distended by drinking 600 ml of water. Upper abdomen scans were performed with spiral CT/e General Electric with the following parameters: slice thickness 3-5 mm, spacing 3 mm, pitch 1,5, reconstruction index 3 mm. After the pre-contrast scans, 100 ml of non-ionic contrast media is administered intravenously with an injection rate of 30 ml/sec. Scan delay time - 30 seconds after start of injection. Exposition data-120 kV, 180 mAs. Carcinoma localized in the antral part of the stomach was demonstrated in 7 patients. The staging showed: I stage - one patient, II stage - 2, III stage - 1 and IV stage - three patients. According to the macro morphological characteristic: exophytic type - 4, endophytic tumor - 1, ulcerous tumor - 1 and early carcinoma - 1 patient. In our material only male patients were present. Early carcinoma was demonstrated in a male patient at an age of 80 years old. An enhancing nodular local thickness was visualized. Differential diagnosis between malignant and benign ulcer is necessary in certain cases. It is performed on the contrast scans, the malignant process enhances twice its density, When performing a purposive CT examination it is possible to diagnose neoplasms in the antral part of the stomach, from stage i to IV with different macro morphologic characteristic

Ancillary lung parenchymal findings at spiral CT scanning in pulmonary embolism. Relationship to chest sonography

International Nuclear Information System (INIS)

Reissig, Angelika; Heyne, Jens-Peter; Kroegel, Claus

2004-01-01

Introduction/objective: The aim of the study was to compare findings of transthoracic sonography (TS) and of spiral computed tomography (sCT) in patients with suspected pulmonary embolism (PE). Methods and patients: Peripheral parenchymal and pleural findings of TS and sCT were compared in 62 patients (25 females, 37 males; mean age 62.2 years) with suspected PE. Results: In 39 patients PE was established, of whose pleura-based lesions could be detected by TS in 30 patients and by sCT in 31 patients. Whilst in three of the patients parenchymal lesions were exclusively detected by sonography, no peripheral abnormalities could be discovered with either technique in five patients. Among the nine patients lacking peripheral abnormalities on sonography, four revealed peripheral lesions in sCT. In 23 patients without PE, peripheral consolidations at CT were detected in six patients whereas two showed lesions on TS. With respect to the appearance, pleura-based wedge-shaped consolidations were the main parenchymal alterations (82.4% at TS, 66.1% at sCT) as compared with non-wedge-shaped consolidations (17.6% at TS, 33.9% at sCT). Peripheral lesions were located preferentially within the lower lobes. In addition, both localised and basal pleural effusion associated with PE could be demonstrated in 58.9% at TS and in 23.1% by sCT. Discussions and conclusion: The study shows that in PE parenchymal and pleural changes are detectable by TS and sCT. If parenchymal findings are present at sCT, peripheral PE should be considered, even in the absence of directly visible emboli

Ancillary lung parenchymal findings at spiral CT scanning in pulmonary embolism. Relationship to chest sonography

Energy Technology Data Exchange (ETDEWEB)

Reissig, Angelika E-mail: angelika.reissig@med.uni-jena.de; Heyne, Jens-Peter; Kroegel, Claus

2004-03-01

Introduction/objective: The aim of the study was to compare findings of transthoracic sonography (TS) and of spiral computed tomography (sCT) in patients with suspected pulmonary embolism (PE). Methods and patients: Peripheral parenchymal and pleural findings of TS and sCT were compared in 62 patients (25 females, 37 males; mean age 62.2 years) with suspected PE. Results: In 39 patients PE was established, of whose pleura-based lesions could be detected by TS in 30 patients and by sCT in 31 patients. Whilst in three of the patients parenchymal lesions were exclusively detected by sonography, no peripheral abnormalities could be discovered with either technique in five patients. Among the nine patients lacking peripheral abnormalities on sonography, four revealed peripheral lesions in sCT. In 23 patients without PE, peripheral consolidations at CT were detected in six patients whereas two showed lesions on TS. With respect to the appearance, pleura-based wedge-shaped consolidations were the main parenchymal alterations (82.4% at TS, 66.1% at sCT) as compared with non-wedge-shaped consolidations (17.6% at TS, 33.9% at sCT). Peripheral lesions were located preferentially within the lower lobes. In addition, both localised and basal pleural effusion associated with PE could be demonstrated in 58.9% at TS and in 23.1% by sCT. Discussions and conclusion: The study shows that in PE parenchymal and pleural changes are detectable by TS and sCT. If parenchymal findings are present at sCT, peripheral PE should be considered, even in the absence of directly visible emboli.

Morphometric analysis of stab wounds by MSCT and MRI after the instillation of contrast medium.

Science.gov (United States)

Fais, Paolo; Cecchetto, Giovanni; Boscolo-Berto, Rafael; Toniolo, Matteo; Viel, Guido; Miotto, Diego; Montisci, Massimo; Tagliaro, Franco; Giraudo, Chiara

2016-06-01

To analyze the morphology and depth of stab wounds experimentally produced on human legs amputated for medical reasons using multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) after the instillation of a single contrast medium solution (CMS). For morphological analysis, MSCT and MRI scans were performed before and after the instillation of CMS into the wound cavity. Depth measurements were performed on the sagittal view only after CMS instillation. Subsequently, each wound was dissected using the layer-by-layer technique and the depth was measured by a ruler. One-way between-groups pairwise analysis of variance (ANOVA) and Bland-Altman plot analysis were used for comparing radiological and anatomical measurements. Unenhanced MSCT images did not identify the wound channels, whereas unenhanced MRI evidenced the wound cavity in 50 % of cases. After the instillation of CMS, both MSCT and MRI depicted the wound channel in all the investigated stabbings, although the morphology of the cavity was irregular and did not resemble the shape of the blade. The radiological measurements of the wounds' depth, after the application of CMS, exhibited a high level of agreement (about 95 % at Bland-Altman plot analysis) with the anatomical measurements at dissection. A similar systematic underestimation, however, has been evidenced for MSCT (average 11.4 %; 95 % CI 7-17) and MRI (average 9.6 %; 95 % CI 6-13) data after the instillation of CMS with respect to wound dissection measurements. MSCT and MRI after the instillation of CMS can be used for depicting the morphometric features of stab wounds, although depth measurements are affected by a slight systematic underestimation compared to layer-by-layer dissection.

Diagnosis of bronchiectasis with multislice spiral CT: accuracy of 3-mm-thick structured sections

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Remy-Jardin, Martine; Amara, Assia; Campistron, Philippe; Mastora, Ioana; Remy, Jacques [Department of Radiology, Hospital Calmette, University Center of Lille, Boulevard Jules Leclerc, 59037, Lille Cedex (France); Delannoy, Valerie; Duhamel, Alain [Department of Medical Statistics, University of Lille, Place de Verdun, 59037, Lille Cedex (France)

2003-05-01

The aim of this study was to evaluate the accuracy of 3-mm-thick reconstructed sections in the diagnosis of bronchiectasis with multislice CT (MSCT). Forty consecutive patients suspected of bronchiectasis (23 females, 17 males; mean age 51 years) underwent MSCT of the entire thorax with a 4 x 1-mm collimation (120 kV, 0.5 s/rotation, 80 mAs/slice) and a pitch of 1.75. From each data set (mean z-axis coverage: 257 mm; mean duration: 21 s), two series of images were systematically generated: 1-mm (group 1) and 3-mm (group 2)-thick reconstructed scans. Both series of images were obtained at 10-mm intervals and reconstructed with a high-spatial-frequency algorithm. Two observers independently analyzed the presence of bronchiectasis and associated abnormalities in group-1 and group-2 lung images. No significant difference between group 1 and group 2 was found in: (a) the detection of bronchiectasis, identified in 24 patients (60%) in group 1 and in 23 patients (57.5%) in group 2 (p=0.08); (b) the evaluation of the extent of bronchiectasis, identifying focal bronchiectasis in 10 patients (25%) in group 1 and 7 patients (17.5%) in group 2 (p=0.39) and multifocal bronchiectasis in 16 patients (40%) in both groups; (c) the characterisation of bronchiectasis (cylindral bronchiectasis: group 1, n=24, 60%; group 2, n=21, 53%, p=0.08); varicose bronchiectasis: group 1, n=5, 12.5%; group 2, n=6, 15%, p=0.56; and cystic bronchiectasis: group 1, n=2, 5%; group 2, n=2, 5%. Apart from the identification of abnormal bronchial wall thickening (group 2, n=35, 87.5%, vs group 1, n=31, 77.5%, p<0.05), recognition of associated bronchopulmonary anomalies did not differ between the two groups. This study demonstrates a comparable accuracy of the 3- and 1-mm-thick reconstructed scans in the detection and characterization of bronchiectasis. These results suggest the potential usefulness of 3-mm-thick scans generated from 4 x 2.5-mm acquisitions in the screening of bronchiectasis, which would

Comparison of Conventional Versus Spiral Computed Tomography with Three Dimensional Reconstruction in Chronic Otitis Media with Ossicular Chain Destruction

International Nuclear Information System (INIS)

Naghibi, Saeed; Seifirad, Sirous; Adami Dehkordi, Mahboobeh; Einolghozati, Sasan; Ghaffarian Eidgahi Moghadam, Nafiseh; Akhavan Rezayat, Amir; Seifirad, Soroush

2016-01-01

Chronic otitis media (COM) can be treated with tympanoplasty with or without mastoidectomy. In patients who have undergone middle ear surgery, three-dimensional spiral computed tomography (CT) scan plays an important role in optimizing surgical planning. This study was performed to compare the findings of three-dimensional reconstructed spiral and conventional CT scan of ossicular chain study in patients with COM. Fifty patients enrolled in the study underwent plane and three dimensional CT scan (PHILIPS-MX 8000). Ossicles changes, mastoid cavity, tympanic cavity, and presence of cholesteatoma were evaluated. Results of the two methods were then compared and interpreted by a radiologist, recorded in questionnaires, and analyzed. Logistic regression test and Kappa coefficient of agreement were used for statistical analyses. Sixty two ears with COM were found in physical examination. A significant difference was observed between the findings of the two methods in ossicle erosion (11.3% in conventional CT vs. 37.1% in spiral CT, P = 0.0001), decrease of mastoid air cells (82.3% in conventional CT vs. 93.5% in spiral CT, P = 0.001), and tympanic cavity opacity (12.9% in conventional CT vs. 40.3% in spiral CT, P=0.0001). No significant difference was observed between the findings of the two methods in ossicle destruction (6.5% conventional CT vs. 56.4% in spiral CT, P = 0.125), and presence of cholesteatoma (3.2% in conventional CT vs. 42% in spiral CT, P = 0.172). In this study, spiral CT scan demonstrated ossicle dislocation in 9.6%, decrease of mastoid air cells in 4.8%, and decrease of volume in the tympanic cavity in 1.6%; whereas, none of these findings were reported in the patients' conventional CT scans. Spiral-CT scan is superior to conventional CT in the diagnosis of lesions in COM before operation. It can be used for detailed evaluation of ossicular chain in such patients

Blind deblurring of spiral CT images - comparative studies on edge-to-noise ratios

International Nuclear Information System (INIS)

Jiang Ming; Wan Ge; Skinner, Margaret W.; Rubinstein, Jay T.; Vannier, Michael W.

2002-01-01

A recently developed blind deblurring algorithm based on the edge-to-noise ratio has been applied to improve the quality of spiral CT images. Since the discrepancy measure used to quantify the edge and noise effects is not symmetric, there are several ways to formulate the edge-to-noise ratio. This article is to investigate the performance of those ratios with phantom and patient data. In the phantom study, it is shown that all the ratios share similar properties, validating the blind deblurring algorithm. The image fidelity improvement varies from 29% to 33% for different ratios, according to the root mean square error (RMSE) criterion; the optimal iteration number determined for each ratio varies from 25 to 35. Those ratios that are associated with most satisfactory performance are singled out for the image fidelity improvement of about 33% in the numerical simulation. After automatic blind deblurring with the selected ratios, the spatial resolution of CT is substantially refined in all the cases tested

Measuring of the airway dimensions with spiral CT images: an experimental study in Japanese white big-ear rabbits

International Nuclear Information System (INIS)

Han Xinwei; Lu Huibin; Ma Ji; Wu Gang; Wang Nan; Si Jiangtao

2009-01-01

Objective: To measure the length, angle and their correlation of the main anatomical dimensions of the trachea and bronchus in experimental Japanese white big-ear rabbits with the help of spiral CT 3D images, in order to lay the foundation of treating the airway disorders with stenting in animal experiment. Methods: Multi-slice CT scanning of cervico-thoracic region was performed in 30 healthy adult Japanese white big-ear rabbits, the longitudinal, transversal dimensions of the trachea, the glottis-carina length, the inner diameter and length of bronchi, and the angle formed by bronchial long axis and sagittal section were measured. Results: No significant difference was found in the inner diameters of various parts of the trachea and upper apical bronchi. The angle formed by bronchial long axis and sagittal section were smaller than that of the left ones. And the inner diameters of the right main bronchus was bigger than the left ones. Conclusion: The complex branching structure of the rabbit airway tree can be well displayed on spiral CT 3D images. Through measuring and statistical analysis of the results the authors have got a regressive equation for estimating the value of the inner diameter, length, angle, etc. concerning the airway tree, which is very helpful for providing the useful anatomical parameters in rabbit experiment. (authors)

Blood flow patterns of solitary pulmonary nodules with enhancement: clinical value of multi-slice spiral CT

International Nuclear Information System (INIS)

Li Shenjiang; Xiao Xiangsheng; Liu Shiyuan; Liu Huimin; Li Yuli; Li Huimin; Li Chengzhou; Zhang Chenshi; Tao Zhiwei; Yang Chunshan; Jiang Qingjun; Ouyang Lin; Yu Hong

2004-01-01

Objective: To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT) for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and the correlation of vascular endothelial growth factor (VEGF)-positive tumor angiogenesis and the quantifiable parameters of blood flow pattern in solitary bronchogenic adenocarcinoma. Methods Seventy-eight patients with SPNs (with strong enhancement) (diameter ≤4 cm; 68 malignant; 10 active inflammatory) underwent multi-location dynamic contrast enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s by using an autoinjector) serial CT. Precontrast and postcontrast attenuation on every scan was recorded. Perfusion, peak height, and ratio of peak height of the SPN to that of the aorta were calculated. Perfusion was calculated from the maximum gradient of the time-attenuation curve and the peak height of the aorta. The quantifiable parameters (perfusion, peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta and mean transit time) of blood flow pattern in 30 VEGF-positive solitary bronchogenic adenocarcinoma were compared with microvessel densities (MVD) and VEGF expression by immunohistochemistry. Results: No statistically significant difference in the peak height was found between malignant (35.79 ± 10.76) HU and active inflammatory (39.76 ± 4.59) HU nodules (t=1.148, P=0.255). SPN-to-aorta ratio (14.27 ± 4.37)% and perfusion value (3.02 ± 0.96)ml -1 ·min -1 ·kg -1 in malignant SPNs were significantly lower than those of active inflammatory nodules(18.51 ± 2.71)%, (6.34 ± 4.39)ml -1 ·min -1 ·kg -1 (t=2.978, P=0.004, t=5.590, P -1 ·min -1 ·kg -1 , mean transit time (14.86 ± 5.84) s, and MVD (70.15 ± 20.03). Each of peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta, and perfusion correlated positively with MVD (r=0.781, P<0.0001; r=0

Exact cone beam CT with a spiral scan

International Nuclear Information System (INIS)

Tam, K.C.; Samarasekera, S.; Sauer, F.

1998-01-01

A method is developed which makes it possible to scan and reconstruct an object with cone beam x-rays in a spiral scan path with area detectors much shorter than the length of the object. The method is mathematically exact. If only a region of interest of the object is to be imaged, a top circle scan at the top level of the region of interest and a bottom circle scan at the bottom level of the region of interest are added. The height of the detector is required to cover only the distance between adjacent turns in the spiral projected at the detector. To reconstruct the object, the Radon transform for each plane intersecting the object is computed from the totality of the cone beam data. This is achieved by suitably combining the cone beam data taken at different source positions on the scan path; the angular range of the cone beam data required at each source position can be determined easily with a mask which is the spiral scan path projected on the detector from the current source position. The spiral scan algorithm has been successfully validated with simulated cone beam data. (author)

Accuracy of spiral CT and 3D reconstruction in the detection of acute pulmonary embolism - development of an animal model using porcine lungs and technical specimens. Development of an animal model using porcine lungs and technical specimens

International Nuclear Information System (INIS)

Ries, B.G.; Kauczor, H.U.; Thelen, M.; Konerding, M.A.

2001-01-01

Purpose: To develop a model for simulation the CT morphologic situation of acute pulmonary embolism, to evaluate the accuracy of spiral CT and 3D reconstruction in the detection of artificial emboli and to investigate the influence of the orientation of emboli depending on z-axis orientation. Materials and Methods: Standardized artificial emboli made of wax and of defined size and shape were positioned into the pulmonary arteries of porcine lungs. Castings of the embolized pulmonary arterial trees were made by injection of a special opaque resin. After performance of spiral CT the data sets of the emboli and the pulmonary arteries were post-processed. The 3D segmentations were compared with the anatomic preparation to evaluate the accuracy of spiral CT/3D reconstruction-technique. Technical specimens simulating CT-morphology of acute embolized vessels underwent spiral CT in six different positions with respect to the z-axis. The CT data were reconstructed using a standardized and a contrastadapted method with interactive correction. The 3D emboli were analysed under qualitative aspects, and measurements of their extent were done. Results: In nearly 91%, there was complete agreement between CT and the corresponding findings at the anatomical preparation. Measurements of the 3D reconstructed technical specimens showed discrepancies of shape and size in dependence of the size of the original preparation, orientation and reconstruction technique. Overestimation up to 4 mm and underestimation to 2,2 mm were observed. Measurements of preparations with heights from 14 to 26 mm showed variances of ±1,5 mm (∝6-11%). Conclusion: The presented models are suitable to simulate CT morphology of acute pulmonary embolism under ex-vivo conditions. Accuracy in the detection of artificial emboli using spiral CT/3D reconstruction is affected by localization, size and orientation of the emboli and the reconstruction technique. (orig.) [de

A new approximate algorithm for image reconstruction in cone-beam spiral CT at small cone-angles

International Nuclear Information System (INIS)

Schaller, S.; Flohr, T.; Steffen, P.

1996-01-01

This paper presents a new approximate algorithm for image reconstruction with cone-beam spiral CT data at relatively small cone-angles. Based on the algorithm of Wang et al., our method combines a special complementary interpolation with filtered backprojection. The presented algorithm has three main advantages over Wang's algorithm: (1) It overcomes the pitch limitation of Wang's algorithm. (2) It significantly improves z-resolution when suitable sampling schemes are applied. (3) It avoids the waste of applied radiation dose inherent to Wang's algorithm. Usage of the total applied dose is an important requirement in medical imaging. Our method has been implemented on a standard workstation. Reconstructions of computer-simulated data of different phantoms, assuming sampling conditions and image quality requirements typical to medical CT, show encouraging results

Spiral hydro-CT of the pancreas in the thin-slice method

International Nuclear Information System (INIS)

Richter, G.M.; Simon, C.; Hoffmann, V.; DeBernardinis, M.; Seelos, R.; Senninger, N.; Kauffmann, G.W.

1996-01-01

In an open prospective study, 151 patients with a suspected pancreatic neoplasm based on clinical, laboratory or other imaging data were examined between May 94 and October 95. Our newly developed Hydro-CT methodology included intravenous injection of 40 mg N-butylscopolaminium bromide (Buscopan) for intestinal paralysis, gastric and duodenal wall distension by oral administration of an average of 1.5 l warm tap water, 30 RAO patient positioning, an individualized contrast injection technique as determined beforehand by time-to-peak measurement in the portal vein and thin-slice spiral CT (3 mm increment, 6 mm table feed and 3 mm secondary reconstruction). A detailed evaluation form was used to assess (1) tumor detection rate, (2) differentiation of malignant versus benign disease, (3) differential diagnosis, and (4) accuracy of assessment of resectability by identification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, portal vein and celiac trunk, superior mesenteric, splenic and hepatic arteries. As the gold standard for positive tumor detection surgery and microscopic diagnosis were used, and for negative tumor detection an event-free survival of 6 months. Almost all examinations were well tolerated. In only 4% was on-site administration of a gastric tube required because of vomiting. In 2% of the patients a slight allergic reaction to be contrast medium was seen. The prevalence of a pancreatic neoplasm was 38%. In tumor detection Hydro-CT reached an overall accuracy of 97.4% with a sensitivity of 100% and a specificity of 95.9%. In the differentiation of benign versus malignant disease Hydro-CT reached an overall accuracy of 89.7% with a sensitivity of 92.5% and a specificity of 83.3%. The prevalence of a pancreatic carcinoma was 24%; 4% other malignant tumors were found (distal common bile duct carcinoma, cystadenocarcinoma). (orig./MG) [de

The selection of window width and levels for measuring the airway dimensions with spiral CT scan: an experimental study in Japanese white big-ear rabbits

International Nuclear Information System (INIS)

Han Xinwei; Lu Huuibing; Wu Gang; Ma Ji; Wang Nan; Si Jiangtao

2009-01-01

Objective: To investigate the optimal window width and window level for measuring the airway dimensions with spiral CT scan in Japanese white big-ear rabbits so as to lay the foundation for airway stenting in animal experiments. Methods: Multi-slice spiral CT scanning of cervico-thoracic region was performed in 30 healthy adult Japanese white big-ear rabbits, the anteroposterior and transversal diameter of the thoracic trachea, the anteroposterior diameter of the right and left bronchus were measured with lung window, mediastinum window and special fat window separately. The revealing rate of the tracheal wall and the measuring results in different windows and levels were recorded and compared with the anatomical data. The differences of the relevant data were statistically analyzed. Results: With lung window, the tracheal wall was well demonstrated, but the relevant data were smaller than that with mediastinum window. With mediastinum window, the data were bigger and the tracheal wall border appeared blurred. The results obtained with fat window were close to the actual anatomical data. Conclusion: For accurately measuring the anteroposterior and transversal diameter of the thoracic trachea in Japanese white big-ear rabbits with multi- slice spiral CT scan, fat window should be adopted, which is helpful for the preparation of tracheal and bronchial stents. (authors)

Preoperative evaluation of the abdominal aortic aneurysm using spiral CT

International Nuclear Information System (INIS)

Chisuwa, Hisanao; Nishimaki, Keiji; Arai, Masayuki; Honda, Haruyasu; Urata, Koichi; Miyagawa, Yusuke; Makuuchi, Masatoshi; Shimizu, Mikio; Okamoto, Kohei.

1995-01-01

Six patients with abdominal aortic aneurysm (AAA) were studied with three-dimensionally reconstructed CT angiography (3D-CTA) in order to evaluate its usefulness as a diagnostic tool for vascular surgery patients. Images of the intravenously contrasted abdominal aorta were obtained with spiral scan during a single breath hold. The images of the abdominal aorta and its major branches were three-dimensionally reconstructed with a shaded surface display mode. The three-dimensional image reconstruction was successful in all the six cases and performed without difficulties. Shaded surface display presented a deficit to depict the aortic wall with mural thrombus. However, multidirectional display of the abdominal aorta and its branches facilitated interpretation of the anatomical details of the lesions and planning of surgical repair. 3D-CTA is an alternative to conventional aortography for preoperative diagnosis of AAA. Moreover it was shown to be noninvasive, easy to proceed. It presented good angiographical resolution that can be used as a precise diagnostic tool in vascular surgery. (author)

Technique and value of three dimensional reconstruction of stones in the renal pelvis using spiral CT

International Nuclear Information System (INIS)

Fink, B.K.; Fink, U.; Pentenrieder, M.; Kohz, P.; Englmeier, H.K.; Schmeller, N.

1994-01-01

5 patients with staghorn calculi in the renal pelvis were examined by spiral CT. From the raw data three dimensional reconstructions of the stones were obtained. In all patients it was possible to compare the three dimensional model with the stone following performance of percutaneous lithopaxy and endoscopic removal of the fragments. In all cases the three dimensional reconstruction provided a realistic image of the stones and was of practical value for the urologist for preoperative diagnosis and intraoperative control. (orig.) [de

Combined SPECT/CT improves detection of initial bone invasion and determination of resection margins in squamous cell carcinoma of the head and neck compared to conventional imaging modalities

Energy Technology Data Exchange (ETDEWEB)

Kolk, A. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Klinik und Poliklinik fuer Mund-Kiefer und Gesichtschirurgie, Muenchen (Germany); Schuster, T. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Institute of Medical Statistics and Epidemiology, Munich (Germany); Chlebowski, A.; Kesting, M.; Bissinger, O.; Weitz, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Lange, P. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Diagnostic Radiology, Munich (Germany); Scheidhauer, K.; Schwaiger, M.; Dinges, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany)

2014-07-15

Knowledge of the presence and extent of bone infiltration is crucial for planning the resection of potential bone-infiltrating squamous cell carcinomas of the head and neck (HNSCC). Routinely, plain-film radiography, multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) are used for preoperative staging, but they show relatively high rates of false-positive and false-negative findings. Scintigraphy with {sup 99m}Tc-bisphosphonate has the ability to show increased metabolic bone activity. If combined with anatomical imaging (e.g. (SPECT)/CT), it facilitates the precise localization of malignant bone lesions. The aim of this study was to analyse the indications and advantages of SPECT/CT compared with standard imaging modalities and histology with regard to specificity and sensitivity A longitudinally evaluated group of 30 patients with biopsy-proven HNSCC adjacent to the mandible underwent {sup 99m}Tc-bisphosphonate SPECT/CT, MRI, MSCT and conventional radiography before partial or rim resection of the mandible was performed. Bone infiltration was first evaluated with plain films, MSCT and MRI. In a second reading, SPECT/CT data were taken into account. The results (region and certainty of bone invasion) were evaluated among the different imaging modalities and finally compared with histological specimens from surgical resection as the standard of reference. For a better evaluation of the hybrid property of SPECT/CT, a retrospectively evaluated group of 20 additional patients with tumour locations similar to those of the longitudinally examined SPECT/CT group underwent SPECT, MSCT and MRI. To assess the influence of dental foci on the specificity of the imaging modalities, all patients were separated into two subgroups depending on the presence or absence of teeth in the area of potential tumour-bone contact. Histologically proven bone infiltration was found in 17 patients (57 %) when analysed by conventional imaging modalities. SPECT/CT data

Combined SPECT/CT improves detection of initial bone invasion and determination of resection margins in squamous cell carcinoma of the head and neck compared to conventional imaging modalities

International Nuclear Information System (INIS)

Kolk, A.; Schuster, T.; Chlebowski, A.; Kesting, M.; Bissinger, O.; Weitz, J.; Lange, P.; Scheidhauer, K.; Schwaiger, M.; Dinges, J.

2014-01-01

Knowledge of the presence and extent of bone infiltration is crucial for planning the resection of potential bone-infiltrating squamous cell carcinomas of the head and neck (HNSCC). Routinely, plain-film radiography, multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) are used for preoperative staging, but they show relatively high rates of false-positive and false-negative findings. Scintigraphy with 99m Tc-bisphosphonate has the ability to show increased metabolic bone activity. If combined with anatomical imaging (e.g. (SPECT)/CT), it facilitates the precise localization of malignant bone lesions. The aim of this study was to analyse the indications and advantages of SPECT/CT compared with standard imaging modalities and histology with regard to specificity and sensitivity A longitudinally evaluated group of 30 patients with biopsy-proven HNSCC adjacent to the mandible underwent 99m Tc-bisphosphonate SPECT/CT, MRI, MSCT and conventional radiography before partial or rim resection of the mandible was performed. Bone infiltration was first evaluated with plain films, MSCT and MRI. In a second reading, SPECT/CT data were taken into account. The results (region and certainty of bone invasion) were evaluated among the different imaging modalities and finally compared with histological specimens from surgical resection as the standard of reference. For a better evaluation of the hybrid property of SPECT/CT, a retrospectively evaluated group of 20 additional patients with tumour locations similar to those of the longitudinally examined SPECT/CT group underwent SPECT, MSCT and MRI. To assess the influence of dental foci on the specificity of the imaging modalities, all patients were separated into two subgroups depending on the presence or absence of teeth in the area of potential tumour-bone contact. Histologically proven bone infiltration was found in 17 patients (57 %) when analysed by conventional imaging modalities. SPECT/CT data revealed

Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications

International Nuclear Information System (INIS)

Loubele, M.; Bogaerts, R.; Van Dijck, E.; Pauwels, R.; Vanheusden, S.; Suetens, P.; Marchal, G.

2009-01-01

Objectives: To compare the effective dose levels of cone beam computed tomography (CBCT) for maxillofacial applications with those of multi-slice computed tomography (MSCT). Study design: The effective doses of 3 CBCT scanners were estimated (Accuitomo 3D, i-CAT, and NewTom 3G) and compared to the dose levels for corresponding image acquisition protocols for 3 MSCT scanners (Somatom VolumeZoom 4, Somatom Sensation 16 and Mx8000 IDT). The effective dose was calculated using thermoluminescent dosimeters (TLDs), placed in a Rando Alderson phantom, and expressed according to the ICRP 103 (2007) guidelines (including a separate tissue weighting factor for the salivary glands, as opposed to former ICRP guidelines). Results: Effective dose values ranged from 13 to 82 μSv for CBCT and from 474 to 1160 μSv for MSCT. CBCT dose levels were the lowest for the Accuitomo 3D, and highest for the i-CAT. Conclusions: Dose levels for CBCT imaging remained far below those of clinical MSCT protocols, even when a mandibular protocol was applied for the latter, resulting in a smaller field of view compared to various CBCT protocols. Considering this wide dose span, it is of outmost importance to justify the selection of each of the aforementioned techniques, and to optimise the radiation dose while achieving a sufficient image quality. When comparing these results to previous dosimetric studies, a conversion needs to be made using the latest ICRP recommendations.

The role of whole body spiral CT in the primary work-up of polytrauma patients - comparison with conventional radiography and abdominal sonography

International Nuclear Information System (INIS)

Albrecht, T.; Schlippenbach, J. von; Wolf, K.J.; Stahel, P.F.; Ertel, W.

2004-01-01

Purpose: To evaluate the role of routine 'whole body spiral CT' in the primary work-up of polytrauma patients for injuries of the thorax, abdomen and spine, and to compare the results with those of conventional radiography of the chest and spine and abdominal ultrasound. Materials and Methods: Fifty consecutive polytrauma patients underwent contrast-enhanced single slice spiral CT (5 mm collimation) from the vertex to the floor of the pelvis as part of the primary work-up after emergency room admission. Overlapping high resolution sections and sagittal reformations of the spine were obtained. Reports of additional chest radiographs (n=43), abdominal ultrasound examinations (n=47) and spine radiographs (n=36) performed in the emergency room were available for retrospective comparison. The 'final diagnoses', which served as the standard of reference, were taken from the patients' records using all information that became available until discharge or death, such as findings from further imaging, surgery and autopsy. Results: CT showed 109 (97%) of 112 thoracic and abdominal soft-tissue injuries. Relevant injuries missed were an early splenic laceration and an early pelvic hematoma, both of which became clinically apparent several hours later. There were 4 false positive CT findings. Conventional chest radiography demonstrated only 20% of thoracic and sonography 22% of abdominal injuries. Chest radiography and sonography produced 2 false-positive findings each. CT showed 66 (87%) of 76 vertebral fractures including all 19 unstable ones. CT missed 5 anterior vertebral body and 5 spinous/transverse process fractures. Conventional radiography found 71% of vertebral fractures including only 50% of the unstable one. (orig.)

Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

DEFF Research Database (Denmark)

Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

2008-01-01

from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0....... Correlations between mean ADC and EI and 15th percentile were both r=0.90 and for MLD r=0.59. There was higher correlation between mean ADC and %predicted DLCO (r=0.90) than between EI and %predicted DLCO (r=0.76). CONCLUSION: HP (3)He-MRI correlates well with density measurements from MSCT and agrees better...

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

Energy Technology Data Exchange (ETDEWEB)

Sun, Kai; Ma, Rui; Wang, Li Jun [Dept. of Radiology, Baotou Central Hospital, Baotou (China); Li, Li Gang; Chen, Jiu Hong [CT BM Clinic Marketing, Siemens Healthcare, Beijing (China)

2012-11-15

To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 {+-} 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 {+-} 0.306 [group A] vs. 1.084 {+-} 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 {+-} 0.16 mSv in group A and 7.1 {+-} 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

International Nuclear Information System (INIS)

Sun, Kai; Ma, Rui; Wang, Li Jun; Li, Li Gang; Chen, Jiu Hong

2012-01-01

To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique. Comparison with angiographic results

Energy Technology Data Exchange (ETDEWEB)

Sato, Yuichi; Matsumoto, Naoya; Kato, Masahiko [Nihon Univ., Tokyo (Japan). Surugadai Hospital] [and others

2003-04-01

The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses {>=}50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses. (author)

Evaluation of image quality and dose in renal colic: comparison of different spiral-CT protocols

International Nuclear Information System (INIS)

Rimondini, A.; Mucelli, R.P.; Dalla Palma, L.; De Denaro, M.; Bregant, P.

2001-01-01

The aim of this study was to test different technical spiral-CT parameters to obtain optimal image quality with reduced X-ray dose. Images were acquired with a spiral-CT system Philips Tomoscan AVE1, using 250 mA, 120 kV, and 1-s rotational time. Three protocols were tested: protocol A with 5-mm thickness, pitch 1.6, slice reconstruction every 2.5 mm; protocol B with 3-mm thickness, pitch 1.6, slice reconstruction every 1.5 mm; and protocol C with 3-mm thickness, pitch 2, slice reconstruction every 1.5 mm. Two phantoms were employed to evaluate the image quality. Axial images were acquired, then sagittal and coronal images were reconstructed. Finally, the absorbed X-ray dose for each protocol was measured. Regarding image quality, 5-mm-thick images (protocol A) showed greater spatial resolution and lower noise compared with 3-mm-thick images (protocols B and C) on the axial plane; 3-mm reconstructed sagittal and coronal images (protocols B and C) showed an improved image quality compared with 5-mm reformatted images (protocol A). Concerning X-ray dose, the mean dose was: protocol A 19.6±0.8 mGy; protocol B 14.4±0.6 mGy; protocol C 12.5±1.0 mGy. Our study supports the use of thin slices (3 mm) combined with pitch of 1.6 or 2 in renal colic for X-ray dose reduction to the patient and good image quality. (orig.)

Thin-section spiral CT evaluation of morphologic effects of aging lung in asymptomatic adult subjects

International Nuclear Information System (INIS)

Li Kuncheng; Liu Jian; Yang Yanhui; Yao Xinyu; Yin Jianguo; Wang Shiwen; He Zuoxiang

2006-01-01

Objective: To evaluate the imaging signs of aging lung in asymptomatic adult subjects by using thin-section spiral CT, and analyze the correlation between the signs and the age of examined cases, as well as probe their clinical application value. Methods: One hundred and six healthy adult subjects were divided into 3 groups: 30 to 44 years (n=31), 45 to 59 years (n=30), and over 60 years (n=45), and all the subjects underwent thin-section spiral CT scans in the upper lung field, the middle lung field and the lower lung field. The evaluation indices included the lung interstitium changes, emphysematous changes, mosaic perfusion, dependent density difference, and pleural thickenning. According to the relative score standard, the above-mentioned indices were totally calculated and converted into the score value. The data were statistically processed with SPSS for Windows. Results: Among the three groups, there were remarkable differences in the indices including the lung interstitium changes, emphysematous changes, and mosaic perfusion, respectively (χ 2 =8.10, 9.73, 15.54, P 2 =3.66, 3.24, P> 0.05). The score values had a significant positive correlation with the age (r=0.709, P<0.01). Conclusion: The signs including the lung interstitium changes, emphysematous changes, mosaic perfusion, the dependent density difference, and pleural thickenning can be found in asymptomatic subjects, and they become prominent as the age increases. HRCT is one of the most important methods for evaluating the early signs of the senile lung. (authors)

The role of spiral CT in patients with intermediate probability V/Q scans: can spiral CT replace pulmonary angiography?

International Nuclear Information System (INIS)

Vu, T.; Glenn, D.; Lovett, I.; Moses, J.; Wadhwa, S.S.; Nour, R.

2000-01-01

Full text: Spiral CT (SCT) has been advocated as a replacement for pulmonary angiography (PA)in patients with intermediate probability (IP) ventilation-perfusion lung scans (V/Q). More generally it has been proposed as a replacement for V/Q to detect Pulmonary Embolism. This study investigates the accuracy of SCT in the IP patient group 31 patients with IP scans (Modified PIOPED criteria) who were not at high risk of contrast nephrotoxicity were enrolled to have both SCT and PA within the 24 hours following their V/Q. Patients were classified as IP due to a single segmental mismatch (n=7) or a matched V/Q abnormality corresponding to CXR opacity (n=21), or both (n=3). PA is the gold standard for the detection of PE. SCT was read by an experienced radiologist blinded to the PA results. SCT was performed according to standard protocol. All SCT were technically satisfactory for interpretation. Pulmonary embolism was present in 9/31 patients (29%). Of the patients with PE detected by PA, SCT was positive in 4 (44% sensitivity). Of the 22 patients who did not have PE, SCT was negative in 21 and positive in one (96% specificity). In conclusion SCT has limited sensitivity for the detection of PE in patients with IP lung scans. SCT may not be an adequate replacement for PA. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

Application of triple rule-out with 64-slice spiral CT in the diagnosis of acute chest pain

International Nuclear Information System (INIS)

Li Pengyu; Li Kuncheng; Du Xiangyin; Cao Lizhen; Liu Jiabin; Yang Yanhuui; Liang Zhigang; Zhu Xiaolian; Liu Jian

2007-01-01

Objective: To investigate the performance of triple rule-out with 64-slice spiral CT in the combined examination of pulmonary artery, thoracic aorta and coronary artery for patients with acute chest pain. Methods: Seventy patients who presented with acute chest pain were included in the study. All of the patients underwent retrospective ECG-gated 64-slice computed tomography triple rule-out examination to evaluate the pulmonary arteries, thoracic aorta and coronary arteries. Multi-planar reconstruction (MPR), maximum intensity projection (MIP), curved-planar reconstruction (CPR) and volume rendering (VR) were used to display pulmonary arteries, thoracic aorta and coronary arteries. We evaluated the image quality of coronary artery and the enhancement of the pulmonary artery and thoracic aorta to estimate if the examination can fulfill the clinical demand for the differential diagnosis of acute chest pain. Results: The mean scan time was (8.5±1.0) s, and the dose of contrast medium injected was 100 ml. There were 95.7% (67/70) of patients whose CT values detected in the pulmonary artery and thoracic aorta after enhancement Were ≥200 HU. The image quality of 85.8% (720/839) coronary segments was classified as excellent, 8.6% (72/839) as good, and 5.6% (47/839) as poor. There were 20 eases with coronary stenoses ≥50%, 2 cases with pulmonary embolism, and 2 cases with aortic dissection. Conclusion: The triple rule-out examination with 64-slice spiral CT could depict pulmonary artery, thoracic aorta, and coronary artery in 8 s with good image quality. It has great potential in the etiological diagnosis for the patients with acute chest pain. (authors)

Spiral CT angiography of renal arteries: comparison with angiography

International Nuclear Information System (INIS)

Wittenberg, G.; Kenn, W.; Tschammler, A.; Sandstede, J.; Hahn, D.

1999-01-01

A prospective study was carried out to determine the accuracy of spiral CT angiography (CTA) in the detection of renal artery stenosis (RAS). Eighty-two patients with arterial hypertension underwent CTA and digital subtraction angiography (DSA) to exclude RAS. For CTA a contrast medium bolus of 100-150 ml (flow rate 3 ml/s) was injected. A 24 or 40 s CTA was started at the origin of the superior mesenteric artery after a delay time determined by test bolus injection (collimation = 2 mm, pitch = 1/1.5). For stenosis detection transverse images supported by maximum intensity projections (MIP) or multiplanar reconstruction projections were used. Of 197 renal arteries examined (including 33 accessory arteries), 34 RAS were visualized using DSA. With CTA, one hemodynamic RAS was missed and one additional hemodynamic RAS was found. Sensitivity/specificity was calculated to be 94 %/98 %. For hemodynamically relevant RAS (> 50 %) the sensitivity/specificity was 96 %/99 %. CTA additionally depicted five adrenal masses. The high accuracy rate of RAS detection thus allows the use of CTA as a screening method in patients with arterial hypertension to exclude a renovascular cause. (orig.)

CT manifestation of hepatic toxoplasmosis

International Nuclear Information System (INIS)

Mao Qing; Yang Yaying; Bao Yanming; He Bo; Wang Kechao; Song Guangyi; Lu Lin; Wang Xiaoli

2005-01-01

Objective: To study the CT manifestation of hepatic toxoplasmosis, and to provide image basis for its clinical diagnosis. Methods: Three patients with hepatic toxoplasmosis were examined by abdomen MSCT (pre- and post-contrast), and were confirmed by laboratory exams. The images were analyzed with information of clinical manifestation. Results: The positive appearances included the enlargement of liver, patches of multiple scattered low densities. Post-contrast lesions appearances: (1) No significant enhancement. (2) No significant occupying effection, and normal vessels inserting lesion occasionally. Conclusion: CT manifestation of hepar toxoplasmosis are some characteristic. But the diagnosis was made by a combination both clinical manifestation and laboratory exams. (authors)

Effect of imaging parameters of spiral CT scanning on image quality for the dental implants. Visual evaluation using a semi-anthropomorphic mandible phantom

International Nuclear Information System (INIS)

Morita, Yasuhiko; Indou, Hiroko; Honda Eiichi

2002-01-01

The purpose of this study was to evaluate the effect of parameters of spiral CT scanning on the image quality required for the planning of dental implants operations. A semi-anthropomorphic mandible phantom which has artificial mandibular canals and teeth roots was used as a standard object for imaging. Spiral CT scans for the phantom settled in water phantom with diameters of 20 and 16 cm were performed. Visibility of the artificial mandibular canal made of a Teflon tube and gaps between tooth apex and canal in the mandibular phantom was evaluated for various combinations of the slice thickness, tables speeds, angles to the canal, and x-ray tube currents. Teeth roots were made of PVC (poly vinyl chloride). The artificial mandibular canal was clearly observed on the images of 1 mm slice thickness. At the same table speed of 2 mm /rotation, the images of thin slice (1 mm) were superior to that of thick slice (2 mm). The gap between teeth apex and canal was erroneously diagnosed on the images with table speeds of 3 mm/rotation. Horizontal scanning in parallel to the canal result in poor image quality for observation of mandibular canals because of the partial volume effect. A relatively high x-ray tube current (125 mA) at thin slice (1 mm) scanning was required for scanning the mandibular phantom in 20 cm water vessel. Spiral scanning with slice thickness of 1 mm and table speeds of 1 of 2 mm/rotation seemed to be suitable for dental implants. The result of this study suggested that diagnosis from two independent spiral scans with a different angle to the object was more accurate and more efficient than single spiral scanning. (author)

Value of multi-slice CT in the classification diagnosis of hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Qian Yi; Zeng Mengsu; Ling Zhiqing; Rao Shengxiang; Liu Yalan

2008-01-01

Objective: To evaluate the value of multi-slice CT (MSCT) classification in the assessment of the hilar cholangiocarcinoma resectability. Methods: Thirty patients with surgically and histopathologically proved hilar cholangiocarcinomas who underwent preoperative MSCT and were diagnosed correctly were included in present study. Transverse images and reconstructed MPR images were reviewed for Bismuth-Corlette classification and morphological classification of hilar cholangiocarcinoma. Then MSCT classification was compared with findings of surgery and histopathology. Curative resectabilty of different types according to Bismuth-Corlette classification and morphological classification were analyzed with chi-square test. Results: In 30 cases, the numbers of Type I, II, IIIa, IIIb and IV according to Bismuth-Corlette classification were 1, 3, 4, 5 and 17. Seventeen patients underwent curative resections, among which 1, 2, 1, 4 and 9 belonged to Type I, II, IIIa, IIIb and IV respectively. However, there was no significant difference in curative resectability among different types of Bismuth-Corlette classification (χ 2 = 0.9875, P>0.05). In present study, the accuracy of MSCT in Bismuth-Corlette classification reached 86.7% (26/30). The numbers of periductal infiltrating, mass forming and intraductal growing type were 13, 13 and 4, while 6, 8 and 3 cases of each type underwent curative resections. There was no significant difference in curative resectability among different types of morphological classification (χ 2 =1.2583, P>0.05). The accuracy of MSCT in morphological classification was 100% (30/30) in this study group. Conclusion: MSCT can make accurate diagnosis of Bismuth-Corlette classification and morphological classification, which is helpful in preoperative respectability assessment of hilar cholangiocarcinoma. (authors)

Predictive value and modeling analysis of MSCT signs in gastrointestinal stromal tumors (GISTs) to pathological risk degree.

Science.gov (United States)

Wang, J-K

2017-03-01

By analyzing MSCT (multi-slice computed tomography) signs with different risks in gastrointestinal stromal tumors, this paper aimed to discuss the predictive value and modeling analysis of MSCT signs in GISTs (gastrointestinal stromal tumor) to pathological risk degree. 100 cases of primary GISTs with abdominal and pelvic MSCT scan were involved in this study. All MSCT scan findings and enhanced findings were analyzed and compared among cases with different risk degree of pathology. Then GISTs diagnostic model was established by using support vector machine (SVM) algorithm, and its diagnostic value was evaluated as well. All lesions were solitary, among which there were 46 low-risk cases, 24 medium-risk cases and 30 high-risk cases. For all high-risk, medium-risk and low-risk GISTs, there were statistical differences in tumor growth pattern, size, shape, fat space, with or without calcification, ulcer, enhancement method and peritumoral and intratumoral vessels (pvalue at each period (plain scan, arterial phase, venous phase) (p>0.05). The apparent difference lied in plain scan, arterial phase and venous phase for each risk degree. The diagnostic accuracy of SVM diagnostic model established with 10 imaging features as indexes was 70.0%, and it was especially reliable when diagnosing GISTs of high or low risk. Preoperative analysis of MSCT features is clinically significant for its diagnosis of risk degree and prognosis; GISTs diagnostic model established on the basis of SVM possesses high diagnostic value.

Spiral CT and radiation dose

International Nuclear Information System (INIS)

Imhof, H.; Schibany, N.; Ba-Ssalamah, A.; Czerny, C.; Hojreh, A.; Kainberger, F.; Krestan, C.; Kudler, H.; Noebauer, I.; Nowotny, R.

2003-01-01

Recent studies in the USA and Europe state that computed tomography (CT) scans compromise only 3-5% of all radiological exams, but they contribute 35-45% of total radiation dose to the patient population. These studies lead to concern by several public authorities. Basis of CT-dose measurements is the computed tomography dose index (CTDI), which was established 1981. Nowadays there are several modifications of the CTDI values, which may lead to confusion. It is suggested to use the standardized CTDI-100 w. value together with the dose length product in all CT-examinations. These values should be printed on all CT-images and allows an evaluation of the individualized patient dose. Nowadays, radiologist's aim must be to work at the lowest maximal diagnostic acceptable signal to noise ratio. To decrease radiation dose radiologist should use low kV and mA, but high pitches. Newly developed CT-dose-reduction soft-wares and filters should be installed in all CT-machines. We should critically compare the average dose used for a specific examination with the reference dose used in this country and/or Europe. Greater differences should caution the radiologist. Finally, we as radiologists must check very carefully all indications and recommend alternative imaging methods. But we have also to teach our customers--patients and medical doctors who are non-radiologists--that a 'good' image is not that which show all possible information, but that which visualize 'only' the diagnostic necessary information

The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

International Nuclear Information System (INIS)

Gao Sijia; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui; Zang Peizhuo; Shi Qiang; Wang Qiang; Liang Chuansheng; Xu Ke

2009-01-01

Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with χ 2 -test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show AVM not AVF. The

The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

Energy Technology Data Exchange (ETDEWEB)

Gao Sijia [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)], E-mail: scarlettgao@126.com; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Zang Peizhuo [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Shi Qiang; Wang Qiang [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Liang Chuansheng [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Xu Ke [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)

2009-07-15

Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with {chi}{sup 2}-test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show

Respiration-correlated spiral CT: A method of measuring respiratory-induced anatomic motion for radiation treatment planning

International Nuclear Information System (INIS)

Ford, E.C.; Mageras, G.S.; Yorke, E.; Ling, C.C.

2003-01-01

We describe a method for generating CT images at multiple respiratory phases with a single spiral CT scan, referred to as respiratory-correlated spiral CT (RCCT). RCCT relies on a respiration wave form supplied by an external patient monitor. During acquisition this wave form is recorded along with the initiation time of the CT scan, so as to 'time stamp' each reconstructed slice with the phase of the respiratory cycle. By selecting the appropriate slices, a full CT image set is generated at several phases, typically 7-11 per cycle. The CT parameters are chosen to optimize the temporal resolution while minimizing the spatial gap between slices at successive respiratory cycles. Using a pitch of 0.5, a gantry rotation period of 1.5 s, and a 180 degree sign reconstruction algorithm results in ∼5 mm slice spacing at a given phase for typical respiration periods, and a respiratory motion within each slice that is acceptably small, particularly near end expiration or end inspiration where gated radiotherapy is to occur. We have performed validation measurements on a phantom with a moving sphere designed to simulate respiration-induced tumor motion. RCCT scans of the phantom at respiratory periods of 4, 5, and 6 s show good agreement of the sphere's motion with that observed under fluoroscopic imaging. The positional deviations in the sphere's centroid between RCCT and fluoroscopy are 1.1±0.9 mm in the transaxial direction (average over all scans at all phases ±1 s.d.) and 1.2±1.0 mm in the longitudinal direction. Reconstructed volumes match those expected on the basis of stationary-phantom scans to within 5% in all cases. The surface distortions of the reconstructed sphere, as quantified by deviations from a mathematical reference sphere, are similar to those from a stationary phantom scan and are correlated with the speed of the phantom. A RCCT scan of the phantom undergoing irregular motion, demonstrates that successful reconstruction can be achieved even with

Understanding about diagnosis of acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT

International Nuclear Information System (INIS)

Jiang Ruizhou; Chen Jincheng

2009-01-01

Objective: To have a further study of the value of MSCT in diagnosing acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT. Methods: A 46-year-old female patient with the history of abdominal operation was found having acute mechanical small bowel obstruction through plain X-ray radiograph. 64-slice MSCT was performed afterwards (plain scan + 3 stage contrast scans). Hence, evidence is provided for operation. Results: Using the technique of MSCT for the patient can promptly approach the diagnosis of jejuno-jejunal intussusception with severe bowel obstruction; no small bowel tumor or other organic lesion found in this case. With the patient who has the history of abdominal operations, MSCT can predict the reason of adhesion causing bowel intussusception, and provide the evidence for operation; whereas MSCT with contrast media offers a further investigation of the blood supply to the bowels through SMA, and observation of blood circulation through the intussuscepting site, which represents venous congestion of intussusception. This case is a retrograde small bowel intussusception and confirmed with operation evidence. A greater amount of gas and fluid is accumulated between the dilated space of middle-distal portion of intussusceptum and intussuscipiens. Nevertheless, less gas at the proximal portion and that can be an important sign for retrograde intussusception. Conclusion: MSCT is a good choice of examination for diagnosis of adult's intussusception. As the literature mentioned the advantages of MSCT for observing the circulation of intussusceptum and whether the diagnosis is antegrade or retrograde intussusception is also essential. (authors)

MSCT-guided percutaneous transthoracic biopsy of lung lesions by using BARD gun: its clinical application

International Nuclear Information System (INIS)

Xu Biao; Chen Gang; Wei Lu

2009-01-01

Objective: To discuss the clinical application of MSCT-guided BARD gun biopsy in diagnosing pulmonary lesions. Methods: Under MSCT-guidance percutaneous transthoracic biopsy of lung with BARD gun was performed in 68 patients with pulmonary lesions. Results: All the procedures were well performed with the technical successful rate of 100%. The final diagnosis was based on the pathological findings or clinical follow-up observation. The accuracy of the qualitative diagnosis was 94.1%. Of 68 patients, squamous cell carcinoma was found in 30, adenocarcinoma in 21, metastases in 7, inflammatory pseudotumor in 3, lung abscess in 2, and tuberculosis in one. The false-negative rate in making diagnosis was 5.9%. The complication occurrence was 8.8%. Conclusion: BARD gun has the advantage of making coaxial-multipoint biopsy. With the help of MSCT-guidance and the full use of the operating advantage of BARD gun, this technique is safe and reliable, with higher accuracy and less complications. (authors)

Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: image reconstruction and assessment of image quality.

Science.gov (United States)

Flohr, Thomas G; Leng, Shuai; Yu, Lifeng; Aiimendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H

2009-12-01

To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch = 1.0 and dual-source scans at pitch = 3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. No significant differences in quantitative measures of image quality were found between single-source scans at pitch = 1.0 and dual-source scans at pitch = 3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6 pitch 3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch = 3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving coronary artery phantom

Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: Image reconstruction and assessment of image quality

International Nuclear Information System (INIS)

Flohr, Thomas G.; Leng Shuai; Yu Lifeng; Allmendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D.; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H.

2009-01-01

Purpose: To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. Methods: With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. Results: No significant differences in quantitative measures of image quality were found between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6≤pitch≤3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch=3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving

Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: Image reconstruction and assessment of image quality

Energy Technology Data Exchange (ETDEWEB)

Flohr, Thomas G.; Leng Shuai; Yu Lifeng; Allmendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D.; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H. [Siemens Healthcare, Computed Tomography, 91301 Forchheim, Germany and Department of Diagnostic Radiology, Eberhard-Karls-Universitaet, 72076 Tuebingen (Germany); Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Siemens Healthcare, Computed Tomography, 91301 Forchheim (Germany); Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

2009-12-15

Purpose: To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. Methods: With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. Results: No significant differences in quantitative measures of image quality were found between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6{<=}pitch{<=}3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch=3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving

Assessment of value of spiral CT in preoperative evaluation of endovascular graft exclusion for abdominal aortic aneurysm

International Nuclear Information System (INIS)

Jing Zaiping; Zhao Jun; Zhu Wenjiang; Xiao Yi

1998-01-01

Purpose: The assess the value of spiral CT (SCT) in preoperative evaluation of endovascular graft exclusion (EVGE) for abdominal aortic aneurysm (AAA). Methods: 41 case with AAA received SCT scanning. Two and three dimensional images were reconstructed, utilizing the shaded surface display (SSD), maximum-intensity Projection (MIP) and multiplanar reformation (MPR). Information were obtained regarding the size and features of AAA, length and diameters of aneurysm's neck, status of the branches of aorta, etc. Results: Nine patients had spinal CT study prior EVGE procedure and the grafts selected according to the parameters obtained by SCT matched perfectly to the needs of deployment. Conclusion: CTA provides high quality images. It is a high-speed and non-invasive method which can provide three-dimensional images of AAA and its main branches and all the parameters needed in EVGE

Use of spiral CT angiography to judge central pulmonary vascular involvement from lung cancer

International Nuclear Information System (INIS)

Tan Qunyou; Zhao Shaohong; Wang Fangze; Cai Zulong

2000-01-01

Objective: To evaluate the accuracy of spiral CT angiography (SCTA) in judging central pulmonary vascular involvement from lung cancer located in the hilum and correlate the resultant images with pathologic and surgical findings. Methods: SCTA was done in 33 patients who were preoperatively diagnosed as having lung carcinoma located in the hilum. Contrast medium was injected at a rate of 3 ml/sec with a power injector. The delay time was from 20 to 25 seconds. The pitch was 1 with 3 mm-collimation. Images of central pulmonary arteries and veins were reconstructed with shaded surface display (SSD), maximum intensity projection (MIP), curved planar reformation (CPR), and multi-planar reformation (MPR). Then the relation between tumor and vessels was assessed prospectively on both 3 mm interval axial CT and SCTA images with comparison to subsequent pathologic or surgical findings. Results: (1) In showing the integrity of central pulmonary arteries and veins, images reconstructed by different ways of SCTA had different strong and weak points. (2) The grading standard in this study, with which the relation between vessels and tumor was judged, reflected the basic and common characters of central pulmonary vascular involvement by tumor located in the hilum. compared with axial CT images, SCTA was more accurate in judging the relation between central pulmonary vessels and tumor, and the correlation of SCTA imaging features with pathological patterns and surgical findings was better than that of axial CT images, P < 0.05 and P < 0.0001, respectively. Conclusion: It was feasible to show the relation between central pulmonary vessel and lung cancer located in the hilum with SCTA. And the accuracy of judging the vascular involvement with SCTA was higher than that with axial CT

Virtual anthropology and forensic identification using multidetector CT.

Science.gov (United States)

Dedouit, F; Savall, F; Mokrane, F-Z; Rousseau, H; Crubézy, E; Rougé, D; Telmon, N

2014-04-01

Virtual anthropology is made possible by modern cross-sectional imaging. Multislice CT (MSCT) can be used for comparative bone and dental identification, reconstructive identification and lesion identification. Comparative identification, the comparison of ante- and post-mortem imaging data, can be performed on both teeth and bones. Reconstructive identification, a considerable challenge for the radiologist, identifies the deceased by determining sex, geographical origin, stature and age at death. Lesion identification combines virtual autopsy and virtual anthropology. MSCT can be useful in palaeopathology, seeking arthropathy, infection, oral pathology, trauma, tumours, haematological disorders, stress indicators or occupational stress in bones and teeth. We examine some of the possibilities offered by this new radiological subspeciality that adds a new dimension to the work of the forensic radiologist. A multidisciplinary approach is crucial and involves communication and data exchange between radiologists, forensic pathologists, anthropologists and radiographers.

Comparison of manual and semi-automatic measuring techniques in MSCT scans of patients with lymphoma: a multicentre study

Energy Technology Data Exchange (ETDEWEB)

Hoeink, A.J.; Wessling, J.; Schuelke, C.; Kohlhase, N.; Wassenaar, L.; Heindel, W.; Buerke, B. [University Hospital Muenster, Department of Clinical Radiology, Muenster (Germany); Koch, R. [University of Muenster, Institute of Biostatistics and Clinical Research (IBKF), Muenster (Germany); Mesters, R.M. [University Hospital Muenster, Department of Haematology and Oncology, Muenster (Germany); D' Anastasi, M.; Graser, A.; Karpitschka, M. [University Hospital Muenchen (LMU), Institute of Clinical Radiology, Muenchen (Germany); Fabel, M.; Wulff, A. [University Hospital Kiel, Department of Clinical Radiology, Kiel (Germany); Pinto dos Santos, D. [University Hospital Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Kiessling, A. [University Hospital Marburg, Department of Diagnostic and Interventional Radiology, Marburg (Germany); Dicken, V.; Bornemann, L. [Institute of Medical Imaging Computing, Fraunhofer MeVis, Bremen (Germany)

2014-11-15

Multicentre evaluation of the precision of semi-automatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their inter-observer variability in multi-slice CT (MSCT) of patients with lymphoma. MSCT data of 63 patients were interpreted before and after chemotherapy by one/tworadiologists in five university hospitals. In 307 lymph nodes, short (SAD)/long (LAD) axis diameter and WHO area were determined manually and semi-automatically. Volume was solely calculated semi-automatically. To determine the precision of the individual parameters, a mean was calculated for every lymph node/parameter. Deviation of the measured parameters from this mean was evaluated separately. Statistical analysis entailed intraclass correlation coefficients (ICC) and Kruskal-Wallis tests. Median relative deviations of semi-automatic parameters were smaller than deviations of manually assessed parameters, e.g. semi-automatic SAD 5.3 vs. manual 6.5 %. Median variations among different study sites were smaller if the measurement was conducted semi-automatically, e. g. manual LAD 5.7/4.2 % vs. semi-automatic 3.4/3.4 %. Semi-automatic volumetry was superior to the other parameters (2.8 %). Semi-automatic determination of different lymph node parameters is (compared to manually assessed parameters) associated with a slightly greater precision and a marginally lower inter-observer variability. These results are with regard to the increasing mobility of patients among different medical centres and in relation to the quality management of multicentre trials of importance. (orig.)

Postmortem MSCT diagnosis of whiplash injuries in a traffic accident: a case report and review of the literature.

Science.gov (United States)

Chen, Min; Huang, Ping; Wan, Lei; Zhang, Jian-Hua; Liu, Ning-Guo; Zou, Dong-Hua; Li, Zheng-Dong; Shao, Yu; Qin, Zhi-Qiang; Chen, Yi-Jiu

2014-04-01

A 45-year-old male car driver died in a traffic accident of four cars rear-end collision on the highway. He was found to have died after a respiratory and cardiac arrest at the scene. No sign of skin injuries was observed from the external inspection. The autopsy was not permitted by the family members because of the local culture. Multislice computed tomography (MSCT) was applied to the current case, showing dislocation of C3-4 cervical vertebrae with II degree, C4 vertebral plate fractures, and spinal stenosis. Post-mortem MSCT confirmed the diagnosis as whiplash injuries. MSCT was verified to be effective in showing the severity of whiplash injuries, thus providing certain objective evidence for medicolegal expertise.

Carotid stenosis: a comparison between MR and spiral CT angiography

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Magarelli, N.; Carriero, A.; Bonomo, L. [Institute of Radiology, University ``G. D`Annunzio``, Chieti (Italy); Scarabino, T.; Simeone, A.L.; Florio, F. [IRCCS, Foggia (Italy); Salvolini, U. [Department of Neuroradiology, University of Ancona (Italy)

1998-06-01

We performed a preliminary study comparing three-dimensional time-of-flight (3 D TOF) magnetic resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and assessment of internal carotid artery stenosis. Digital subtraction angiography (DSA) was the reference examination. We examined 20 patients with signs of cerebrovascular insufficiency, who underwent MRA, SCTA and DSA within a 3 day period. Both internal carotid arteries were assessed by three blinded readers for degree of stenosis at two different levels (bulb and remaining section) giving a total of 80 assessments. Interobserver variability, sensitivity, specificity, diagnostic accuracy, concordance, overestimation and underestimation were assessed. Interobserver variability was not statistically significant. MRA showed higher sensitivity, specificity, diagnostic accuracy and concordance than SCTA (92.0 % vs 80.8 %, 98.2 % vs 96.4 %, 96.3 % vs 91.3 % and 96.0 % vs 88.0 %, respectively). MRA gave rise to a 5.0 % overestimation rate, whereas SCTA occasioned a 7.5 % underestimation rate. These differences are not statistically significant. These results suggest that MRA is a more useful, noninvasive modality for assessment of the internal carotid artery with a more than 70 % stenosis. (orig.) With 6 figs., 4 tabs., 17 refs.

Carotid stenosis: a comparison between MR and spiral CT angiography

International Nuclear Information System (INIS)

Magarelli, N.; Carriero, A.; Bonomo, L.; Scarabino, T.; Simeone, A.L.; Florio, F.; Salvolini, U.

1998-01-01

We performed a preliminary study comparing three-dimensional time-of-flight (3 D TOF) magnetic resonance angiography (MRA) and spiral CT angiography (SCTA) in the detection and assessment of internal carotid artery stenosis. Digital subtraction angiography (DSA) was the reference examination. We examined 20 patients with signs of cerebrovascular insufficiency, who underwent MRA, SCTA and DSA within a 3 day period. Both internal carotid arteries were assessed by three blinded readers for degree of stenosis at two different levels (bulb and remaining section) giving a total of 80 assessments. Interobserver variability, sensitivity, specificity, diagnostic accuracy, concordance, overestimation and underestimation were assessed. Interobserver variability was not statistically significant. MRA showed higher sensitivity, specificity, diagnostic accuracy and concordance than SCTA (92.0 % vs 80.8 %, 98.2 % vs 96.4 %, 96.3 % vs 91.3 % and 96.0 % vs 88.0 %, respectively). MRA gave rise to a 5.0 % overestimation rate, whereas SCTA occasioned a 7.5 % underestimation rate. These differences are not statistically significant. These results suggest that MRA is a more useful, noninvasive modality for assessment of the internal carotid artery with a more than 70 % stenosis. (orig.)

The use of spiral computed tomography in the localization of impacted maxillary canines

Energy Technology Data Exchange (ETDEWEB)

Preda, L.; La Fianza, A.; Di Maggio, E. [Pavia Univ. (Italy)

1998-02-01

The purpose was to compare spiral CT with conventional radiography in planning the orthodontic treatment of impacted permanent maxillary canines. In conclusion, CT facilitates the treatment of impacted canines especially when the teeth are very oblique to the arch. Root resorption is better demonstrated especially on the palatal and buccal surfaces of the adjacent incisors. Spiral CT reduces examination time and risks of accidental movement, thus optimizing multiplanar quality. Examination at 2:1 pitch enables a significant reduction in radiation exposure without loss of image quality. (N.C.)

The use of spiral computed tomography in the localization of impacted maxillary canines

International Nuclear Information System (INIS)

Preda, L.; La Fianza, A.; Di Maggio, E.

1998-01-01

The purpose was to compare spiral CT with conventional radiography in planning the orthodontic treatment of impacted permanent maxillary canines. In conclusion, CT facilitates the treatment of impacted canines especially when the teeth are very oblique to the arch. Root resorption is better demonstrated especially on the palatal and buccal surfaces of the adjacent incisors. Spiral CT reduces examination time and risks of accidental movement, thus optimizing multiplanar quality. Examination at 2:1 pitch enables a significant reduction in radiation exposure without loss of image quality. (N.C.)

Coronary artery imaging with 64-slice spiral CT in atrial fibrillation patients: initial experience

International Nuclear Information System (INIS)

Zhou Xuhui; Yan Chaogui; Xie Hongbo; Li Xiangmin; Li Ziping; Meng Quanfei; Chen Xing

2008-01-01

Objective: To discuss the clinical value of coronary artery imaging using 64-slice spiral CT in patient with atrial fibrillation. Methods: The images of 31 patients with atrial fibrillation who underwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software. Ten patients additionally underwent conventional coronary angiography. The results of conventional coronary angiography were compared with CT coronary angiography of the 10 patients. Results: Image reconstruction was based on absolute timing. The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 85, 41, 5, and 8 vessel segments respectively in patient group with heart rate between 47 beat per minent (bpm) and 69 bpm; and in 63, 16, 13, and 15 vessel segments respectively in patent group with heart rate between 70 bpm and 79 bpm;and in 46, 25, 23, and 24 vessel segments in patient group with heart rate between 80 bpm and 105 bpm. There was significant difference among the three patient groups (H=22.08, P<0.01). Comparison was carried out between CT angiographic findings and conventional angiographic findings of the 125 segments of the coronary arteries in the 10 patients who underwent conventional coronary angiography. The sensitivity and specificity of CT angiography for diagnosing vessel with significant coronary stenosis (≥50% narrowing) was 85.0% (17/20) and 95.2% (100/105), respectively. Positive predictive value was 77.3% (17/22), and negative predictive value was 97.1% (100/103). Coronary CTA underestimated the lesions of 3 vessel segments and overestimated the lesions of 5 vessel segments. Conclusion: Coronary artery imaging with 64-slice row CT had clinical value for patients with atrial fibrillation

The “communication line” suggests occult posterior malleolar fracture associated with a spiral tibial shaft fracture

International Nuclear Information System (INIS)

Hou Zhiyong; Zhang Liping; Zhang Qi; Yao Shuangquan; Pan Jinshe; Irgit, Kaan; Zhang Yingze

2012-01-01

Objectives: To demonstrate radiographical characteristics of the relationship between distal spiral tibial shaft fractures and associated occult posterior malleolar fractures (PMF) that confirmed by CT and MRI. Materials and methods: X-rays for a ninety-six patients with spiral tibia fracture and associated PMF were reviewed. All patients additionally had an ankle CT. Patients with a negative CT scans underwent an ankle MRI. Radiographic observations included fracture location, characteristics, and a presence of a fracture line between the two injuries. Results: The spiral tibia fracture line was contiguous with PMF in 89 of 96 cases after evaluation with the CT and MRI. The line connecting the two injuries, which occurs between the medial inferior apex of the spiral tibia fracture line and the posterior superior apex of the PMF was identified as the “communication line”. In 47 of the 89 conjunction fractures, the “communication line” was detectable preoperatively and in 12 cases postoperatively by anteroposterior radiograph. By using the CT and MRI scans, we found that no “communication line” was present in only 7 cases. Conclusion: It is important to understand the nature of the association between distal spiral tibial shaft fractures and occult posterior malleolar fractures for optimal stabilization of the fracture and for appropriate rehabilitation. The “communication line” is a useful diagnostic clue for early recognition the occult PMF and alerts a closer evaluation of the lateral view and further CT examination.

Assessment of effective radiation dose of an extremity CBCT, MSCT and conventional X ray for knee area using MOSFET dosemeters.

Science.gov (United States)

Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika

2013-12-01

The objective of this study was to assess and compare the organ and effective doses in the knee area resulting from different commercially available multislice computed tomography devices (MSCT), one cone beam computed tomography device (CBCT) and one conventional X-ray radiography device using MOSFET dosemeters and an anthropomorphic RANDO knee phantom. Measurements of the MSCT devices resulted in effective doses ranging between 27 and 48 µSv. The CBCT measurements resulted in an effective dose of 12.6 µSv. The effective doses attained using the conventional radiography device were 1.8 µSv for lateral and 1.2 µSv for anterior-posterior projections. The effective dose resulting from conventional radiography was considerably lower than those recorded for the CBCT and MSCT devices. The MSCT effective dose results were two to four times higher than those measured on the CBCT device. This study demonstrates that CBCT can be regarded as a potential low-dose 3D imaging technique for knee examinations.

Angiogenesis in hepatocellular carcinoma: correlation of single-level dynamic spiral CT scans in arterial phase and expression of α-smooth muscle actin

International Nuclear Information System (INIS)

Liu Yan; Min Pengqiu; Chen Weixia; Zhang Lin

2005-01-01

Objective: To investigate the correlation between the single-level dynamic spiral CT scans (SDCT) of hepatocellular carcinoma (HCC) in arterial phase (AP) and the immunohistochemistry expression of α-smooth muscle actin (ASMA). Methods: 33 cases of suspected HCC undergoing spiral CT plain scan of the whole liver, the single-level dynamic scan of the target level of lesion in AP and finally the whole liver scan in portal-venous phase before operations and proved after were included into the study. After the SDCT, a time-density curve (T-DC) was drawn according to the density change of the region of interest (ROI) of the tumor parenchyma with some parameters calculated, and signs of enhancement evaluated. Slices of post-operation specimen underwent hemotoxylin-eosin (HE) and ASMA immunohistochemistry staining. Then the slices were evaluated with emphases on the ASMA-positive neovasculatures in the parenchyma and mesenchyma of carcinomas, and the average count in a low microscopic field (x 100) was recorded (5 low microscopic field were observed and then an average was calculated.). Finally the immunohistochemistry and histologic results were correlated with image findings. Results: According to the PV of the tumor parenchyma, T-DC was divided into type I, II and III in which the criteria were PV>80, 40 HU< PV< 80 HU and PV<40 HU respectively. In the 33 cases, type I, II and III of T-DC were 3, 17 and 13 cases with PV of 103.30, 57.65 and 33.55 HU respectively. In ASMA immunohistochemistry study, ASMA-positive neovasculatures were devided into type A with a thick wall and B with a thin wall. The mean count of neovasculatures of tumor parenchyma in type I, II and III of T-DC were 10, 4.59 and 1 respectively. Statistically, different types of T-DC were significantly correlated with the count of neovasculatures in the parenchyma of carcinomas (r=-0.567, P<0.01). Homogeneous and inhomogeneous enhancement of carcinomas during SDCT in AP were correlated with the

The role of multi-slice CT in preoperative staging of colonic tumors

International Nuclear Information System (INIS)

Zhang Miao; Chen Kemin; Zhao Zehua; Ling Huawei

2005-01-01

Objective: To determine the accuracy of multi-slice CT pneumocolon in the staging of colonic carcinomas. Methods: Thirty-six patients, who were strongly suspected to have colonic disorders, underwent CT pneumocolon before and after intravenous injection of iodinated contrast agent. CTVE, MPR, SSD, and Raysum images were then obtained by using 4 different softwares in workstation (ADW3.1). 33 positive cases were staged preoperatively according to TNM standard. All cases were proved by surgical or colonoscopic histology. Sensitivity and accuracy of MSCT were determined for the detection of cancers, lymph nodes, and metastases. Results: MSCT pneumocolon examinations demonstrated 32 lesions, missing one case. Sensitivity and positive accuracy value for T staging were 96.97% (32/33) and 87.88% (29/33), respectively; Sensitivity and positive accuracy value for lymph node involvement were 73.91% (17/23) and 69.57% (16/23), respectively. The density of metastatic lymph node was higher than that of normal one. Five cases in M stage were all diagnosed correctly. Conclusion: MSCT pneumocolon is a better method of depicting the colorectal carcinoma. It allows for accurate staging of the colorectal carcinoma, especially detecting the invasion of adjacent tissues and distant metastasis. However the value for early T staging in colorectal carcinoma and minute metastasis of lymph nodes is limited. It is helpful to combine all the findings of lymph nodes, including the size, density, and location, to make a correct diagnosis. (authors)

The comparison of MSCT multi-phase scan features between benign prostatic hyperplasia and prostate cancer

International Nuclear Information System (INIS)

Liu Jingang; Wang Xizhen; Niu Qingliang; Lu Hongkai; Wang Bin

2009-01-01

Objective: To investigate the multi-phase contrast-enhanced features of multi-slice computed tomography (MSCT) of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Methods: Thirty-five BPH and twenty- seven PCa were examined with multi-phase contrast-enhanced MSCT scan. The peak time, maximum attenuation value (MAV) and time density curve (TDC) were recorded, and the slope of the contrast media uptake curve was calculated. Result: Significant differences between BPH and PCa in the type of the curves and the peak time were observed (P<0.01). The slopes of BPH and PCa were 0.45+0.25 and 0.7 6+0.34 respectively, the slope of PCa was higher than that of BPH (P<0.05). MAVs of BPH and PCa were (44.057±10.261) HU and (46.778±11.140) HU respectively, and there was no significant difference between them (P>0.05). Conclusion: The multi-phase MSCT scan can reflect the blood supply and enhancement characters of BPH and PCa, which are important in detection and differential diagnosis of the prostate diseases. (authors)

Scanning technology with multi-slice helical CT in security inspection domain

International Nuclear Information System (INIS)

Wang Jue; Wang Fuquan; Jiang Zenghui

2008-01-01

The paper analyzes the technology conditions of security inspection in home and abroad, and expatiates technology of spiral CT and how to define CT value etc, with studying on the key technology of spiral CT scanning way (X-RAY, detector, technology of pulley etc) and mutual relation. By comparing the present products of security inspection, the conclusion was drawn that it is inevitable to develop the tendency of security inspection area with the checking and discerning the substance by using the technology of multi-layer spiral CT. (authors)

Colorectal carcinoma: preoperative staging with water enema spiral CT

International Nuclear Information System (INIS)

Guan Sheng; Gao Jianbo; Li Yintai; Chen Xuejun; Yang Xuehua; Yang Xiaopeng; Cheng Jingliang

2001-01-01

Objective: To determine the value and limitation of water enema spiral CT (WESCT) in staging of colorectal carcinoma. Methods: Forty-eight patients with histologically proven rectum or colon carcinoma were included in this study. All of them were examined by SCT, and the preoperative staging of TNM and Duke were used based on the findings of SCT. The results of WESCT were compared with those of surgical and pathological examination in all cases. Results: All lesions in the 47 cases were demonstrated clearly by WESCT and the sensitivity was 97.9%; 39 cases of 48 patients were correctly staged with TNM and 42 cases with Duke, the accuracy was 81.3% and 87.5% respectively, which were higher than the overall 50 % accuracy reported by references; (3) The accuracy of WESCT was 89.6% (43/48) in T stage and 81.3% (39/48) in N stage. Three cases in M stage were all diagnosed correctly; Conclusion: WESCT scan is a better method of depicting the colorectal carcinoma. It allows for accurate depiction and staging of colorectal carcinoma, especially detecting the invasion of adjacent tissues and distant metastasis. It is the best imaging method for staging the colorectal carcinoma . However the value of WESCT for early T staging in colorectal carcinoma and minute metastasis of lymph nodes or liver is limited

Evaluation of obstructive airway lesions in complex congenital heart disease using composite volume-rendered images from multislice CT

International Nuclear Information System (INIS)

Choo, Ki Seok; Kim, Chang Won; Lee, Tae Hong; Kim, Suk; Kim, Kun Il; Lee, Hyoung Doo; Ban, Ji Eun; Sung, Si Chan; Chang, Yun Hee

2006-01-01

Multislice CT (MSCT) allows high-quality volume-rendered (VR) and composite volume-rendered images. To investigate the clinical usefulness of composite VR images in the evaluation of the relationship between cardiovascular structures and the airway in children with complex congenital heart disease (CHD). Four- or 16-slice MSCT scanning was performed consecutively in 77 children (mean age 6.4 months) with CHD and respiratory symptoms, a chest radiographic abnormality, or abnormal course of the pulmonary artery on ECHO. MSCT scanning was performed during breathing or after sedation. Contrast medium (2 ml/kg) was administered through a pedal venous route or arm vein in all patients. The VR technique was used to reconstruct the cardiovascular structures and airway, and then both VR images were composed using the commercial software (VoxelPlus 2 ; Daejeon, Korea). Stenoses were seen in the trachea in 1 patient and in the bronchi in 14 patients (19%). Other patients with complex CHD did not have significant airway stenoses. Composite VR images with MSCT can provide more exact airway images in relationship to the surrounding cardiovascular structures and thus help in optimizing management strategies in treating CHD. (orig.)

Low-dose celiac CT angiography with fixed current-time product

International Nuclear Information System (INIS)

Yu Hong; Li Huimin; Li Xiaolin; Zhu Shiqiang; Zhang Jiaming; Wang Xiangming; Zou Xiaofeng

2009-01-01

Objective: To characterize the feasibility of low-dose CT angiography on 16-slice multi-slice computed tomography (16-MSCT), and its relationship to the noise in the pre-contrast image and enhancement value. Methods: Forty-three consecutive patients (male 21, female 22, mean age 59 years, median age 56 years) underwent abdominal 16-MSCT (Toshiba Aquilion 16) with constant scanning parameters including 120 kVp, a 0.5-second gantry rotation time, a pitch of 0.938: 1, and 16 x 1-mm detector collimation. The mA was set at 200 in the pre-contrast scan and 160 in the contrast-enhanced scan. The arterial phase images were retrospectively reconstructed with 1-mm slice thickness, 0.8 mm interval. The pre-contrast noise was defined as the standard deviation (SD) of the aorta at the level of right posterior crura of diaphragm. The enhancement of aorta was also measured at level of celiac artery. The volume rendering of CT angiography was made and classified into three grades (excellent, good, bad). Receiver operating characteristic curve (ROC) was used to evaluate the relationship between the image quality of CT angiography and noise in the pre-contrast image and enhancement value. Results: Twenty-five cases had the aorta enhancement between 300.0-400.0 HU. The sensitivity and specificity of excellent CTA image was 75% and 62%, respectively when the SD was 12.00. Eighteen cases had the aorta enhancement more than 400.0 HU. The sensitivity and specificity of excellent CTA image was all 100% when the SD was 12.25, and 100% and 75%, respectively when the SD was 13.35. The area under curve of CTA image quality and enhancement in receiver-operated characteristic analysis was 0.907. The enhancement was more than 356.7 HU when the sensitivity and specificity of excellent CTA image was 100% and 60%, respectively, and 389.8 HU when 78% and 80%. When the enhancement was more than 442.4 HU, the specificity of excellent CTA image was 100%. Conclusions: MSCT angiography with low radiation

Functional renal perfusion imaging with colour mapping: is it a useful adjunct to spiral CT of in the assessment of abdominal aortic aneurysm (AAA)?

International Nuclear Information System (INIS)

Blomley, Martin J.K.; McBride, Alan; Mohammedtagi, Sima; Albrecht, Thomas; Harvey, Christopher J.; Jaeger, Rolf; Standfield, Nigel J.; Dawson, Peter

1999-01-01

Aim: To ensure optimal timing with pre-operative spiral CT for abdominal aortic aneurysms (AAA), an initial 'timing' single level CT is commonly performed with a small bolus of contrast. This can be exploited to obtain adjunct functional information on renal perfusion. We have investigated the potential of this to measure renal perfusion, to produce colour renal perfusion maps and to predict surgical outcome in infrarenal aortic aneurysm assessment. Methods: We studied 21 patients being assessed for repair of infrarenal AAA. Prior to the spiral CT, a single level through the renal hili and aorta was scanned after the intravenous injection of 25 ml of contrast given at 10 ml/s. Ten 1 s duration scans were performed from 8 to 30 s after injection. Optimal timing for CT angiography can then be determined. Time-density curves were then drawn for both kidneys and aorta using regions of interest (ROIs) or pixel-by-pixel analysis. Renal cortical perfusion was measured using both ROI analysis and pseudocolour perfusion images. Following previous work, perfusion was calculated as the peak upslope of the tissue time density curve divided by peak aortic enhancement. Results: Cortical mean perfusion averaged 2.48 ml/min per ml (range 0.8-3.7 ml/min per ml n=34) and the values obtained agreed with literature expectations. Follow up in the 10 patients proceeding to AAA repair suggest low mean perfusion values and predict a raised postoperative creatinine (P<0.05) Conclusions: Additional functional data and imaging can be obtained from the initial timing scan of a CT study, without requiring a dedicated study

The spiral CT manifestations of the blood supply of primary hepatocellular carcinoma: correlation with pathological findings

International Nuclear Information System (INIS)

Huang Juan; Zhou Xiangping; Liu Rongbo; Chen Xian; Xu Chongyong; Yan Zhihan; Xu Jianying

2000-01-01

Objective: To study the correlation between the CT features of tumor blood supplies and the pathological changes in primary hepatocellular carcinoma (PHCC). Methods: Fifty cases with surgically and pathologically proved PHCC underwent spiral CT scanning (plain + dual-phase). One research group blindly evaluated the CT films obtained. According to tumor contrast enhancement and signals showed on CT, the patterns of PHCC was divided into 4 types: arterial blood supplying, portal blood supplying, arterial combining with portal blood supplying, and poorly blood supplying. Microscopically, PHCC was respectively classified into grade I to IV with Edmonson's standard, and into 4 types (trabecular, pseudo-glandular, compact, scirrhous) with WHO histological grading standard. At last, the CT features of tumor blood supplies were correlated with pathologic changes. Results: 36(72%) cases were supplied by hepatic arterial blood, 6(12%) by arterial combining with portal blood supplying, 4(8%) by portal, and 4(8%) were poorly blood supplying. The patterns of tumor blood supplies in PHCC correlated with tumor cells differentiation (P<0.05). PHCC with better tumor cells differentiation was more associated with portal blood supplies. The patterns of tumor blood supplying in PHCC correlated with the histological type of the tumor cell (P < 0.05). All of the scirrhous PHCC were lack of blood supplies, the entire compact and most of the trabecular PHCC were supplied by a arterial blood. Conclusion: The most of PHCC were supplied by hepatic arterial blood and others were supplied by portal blood, arterial combining with portal blood or lack of blood supplies. Evaluation of tumor blood supplies in PHCC is considered to be useful in differential diagnosis and treatment of PHCC

Approximations of noise covariance in multi-slice helical CT scans: impact on lung nodule size estimation.

Science.gov (United States)

Zeng, Rongping; Petrick, Nicholas; Gavrielides, Marios A; Myers, Kyle J

2011-10-07

Multi-slice computed tomography (MSCT) scanners have become popular volumetric imaging tools. Deterministic and random properties of the resulting CT scans have been studied in the literature. Due to the large number of voxels in the three-dimensional (3D) volumetric dataset, full characterization of the noise covariance in MSCT scans is difficult to tackle. However, as usage of such datasets for quantitative disease diagnosis grows, so does the importance of understanding the noise properties because of their effect on the accuracy of the clinical outcome. The goal of this work is to study noise covariance in the helical MSCT volumetric dataset. We explore possible approximations to the noise covariance matrix with reduced degrees of freedom, including voxel-based variance, one-dimensional (1D) correlation, two-dimensional (2D) in-plane correlation and the noise power spectrum (NPS). We further examine the effect of various noise covariance models on the accuracy of a prewhitening matched filter nodule size estimation strategy. Our simulation results suggest that the 1D longitudinal, 2D in-plane and NPS prewhitening approaches can improve the performance of nodule size estimation algorithms. When taking into account computational costs in determining noise characterizations, the NPS model may be the most efficient approximation to the MSCT noise covariance matrix.

The value of multi-slice spiral CT liver perfusion imaging to evaluate the chronic hepatic fibrosis and cirrhosis

International Nuclear Information System (INIS)

Long Liling; Huang Zhongkui; Ding Ke; Liao Jinyuan; Jiang Jianning

2012-01-01

Objective: To investigate the value of the MSCT liver perfusion imaging parameters in the evaluation of the chronic hepatic fibrosis and cirrhosis. Methods: Liver CT perfusion (CTP) was performed in 107 participants,including 31 patients with mild hepatic fibrosis (S1, S2), 34 patients with severe hepatic fibrosis (S3, S4) and early stage of hepatic cirrhosis which conformed by liver pathologic biopsy, 42 patients with hepatic cirrhosis who had typical clinical and image signs, and 30 healthy subjects as control group. The data of CTP (HAP, PVP, LTP, HPI and TTP) at different stages were obtained with Body perfect CT-syngo CT2007A and control study with histopathologic stage. Compared the study index by the one-way ANOVA analysis. Used Spearman rank correlation to analysis the relationship between liver perfusion imaging parameters and the degrees of the chronic hepatic fibrosis. Used Logistic regression to analysis the maximum regression coefficient among the liver perfusion imaging parameters, which affected the histopathologic stage mostly. Results: In the subgroups of the chronic hepatic fibrosis S1, S2, S3, S4 to the hepatic cirrhosis,HAP values was (28.9 ±8.6), (24.6 ±2.4), (29.2 ±2.3) and (38.9 ± 7.0) ml · 100 ml -1 · min -1 , respectively. HAP decreased firstly,then increased. Statistic analysis showed the difference of HAP between later-stage cirrhosis and other groups (F=40.26, P<0.01). PVP values of above subgroups was (111.3 ± 18.1), (92.9 ±5.3), (73.0 ±9.0) and (54.1 ± 13.8) ml · 100 ml -1 ·min -1 , respectively. TLP values of above subgroups was (140.2 ± 25.9), (117.1 ± 4.5), (102.3 ± 8.7)and (93.0 ± 11.8) ml · 100 ml -1 ·min -1 , respectively. The difference of PVP, TLP among each subgroup was significant (F=136.79, 67.40, respectively, P<0.01). HPI values of above subgroups was (20.4 ± 2.6)%, (21.0 ±2.1)%, (28.5 ±3.1)% and (42.6± 11.1)%, respectively. TTP values of above subgroups was (123.7±22.2), (137.1 ±27.1), (145.0 ±28

Historical review on the development of computed tomography on the occasion of putting a new spiral CT into operation at the University of Veterinary Medicine, Vienna

International Nuclear Information System (INIS)

Henninger, W.

2002-01-01

Linear tomography has been well known since the thirties of the last century. Before and alter World War II attempts of taking cross sections were done radiographically, but image quality was extremely poor. About 1960 A.M. Cormack developed a possibility to measure body densities for radiation therapy. After having attempted digitization of x-ray intensities during tissue penetration, G.N. Hounsfield constructed the first scanner in 1972 - in the first run only to examine the head. Improvements of technology lead to a series of generations of scanners which ended in the development of spiral CT and multi-slice detectors. In veterinary medicine the first papers on the use of CT in small animals were published by clinicians in the United States and in Germany nearly at the same time in 1980. A number of reports appeared afterwards from clinicians worldwide. The technique for examination of the horse was first described in the United States in 1986; in Europe the first CT scanner examining horses was established in Utrecht. At the Radiology Clinic of the University of Veterinary Medicine, Vienna, the first scanner for clinical use started to operate in summer 1993. The diagnostic possibilities improved in 1997 by introduction of a large animal weight bearing table. A new spiral CT has been put into operation in February 2001. CT has dramatically improved diagnostic accuracy in diagnostic imaging and lead to advanced therapy and prognosis for the patient in many specialist fields of veterinary medicine, e.g. neurosurgery, neurology, oncology, or orthopedics. (author)

Single-level dynamic spiral CT of hepatocellular carcinoma: correlation between imaging features and tumor angiogenesis

International Nuclear Information System (INIS)

Chen Weixia; Min Pengqiu; Song Bin; Xiao Bangliang; Liu Yan; Wang Wendong; Chen Xian; Xu Jianying

2001-01-01

Objective: To investigate the correlation of the enhancement imaging features of hepatocellular carcinoma (HCC) and relevant parameters revealed by single-level dynamic spiral CT scanning with tumor microvessel counting (MVC). Methods: The study included 26 histopathologically proven HCC patients. Target-slice dynamic scanning and portal venous phase scanning were performed for all patients. The time-density curves were generated with measurement of relevant parameters including: peak value (PV) and contrast enhancement ratio (CER), and the gross enhancement morphology analyzed. Histopathological slides were carefully prepared for the standard F8RA and VEGF immunohistochemical staining and tumor microvessel counting and calculation of VEGF expression percentage of tumor cells. The enhancement imaging features of HCC lesions were correlatively studied with tumor MVC and VEGF expression. Results: Peak value of HCC lesions were 7.9 to 75.2 HU, CER were 3.8% to 36.0%. MVC were 6 to 91, and the VEGF expression percentage were 32.1% to 78.3%. The PV and CER were significantly correlated with tumor tissue MVC (r = 0.508 and 0.423, P < 0.01 and 0.05 respectively). There were no correlations between PV and CER and VEGF expression percentage. Both the patterns of time-density curve and the gross enhancement morphology of HCC lesions were also correlated with tumor MVC, and reflected the distribution characteristics of tumor microvessels within HCC lesions. A close association was found between the likelihood of intrahepatic metastasis of HCC lesions with densely enhanced pseudo capsules and the presence of rich tumor microvessels within these pseudo capsules. Conclusion: The parameters and the enhancement imaging features of HCC lesions on target-slice dynamic scanning are correlated with tumor MVC, and can reflect the distribution characteristics of tumor microvessels within HCC lesions. Dynamic spiral CT scanning is a valuable means to assess the angiogenic activity and

Three-dimensional helical (spiral) CT angiography. Visualization of vessels in the maxillofacial regions

International Nuclear Information System (INIS)

Hanawa, Shigeo; Sakamoto, Hidetomo; Mori, Shin-ichiro; Kagawa, Toyohiro; Seze, Ryosuke; Ishioka, Hisakazu; Tashiro, Himiko; Ogawa, Kazuhisa; Wada, Tadako

1998-01-01

Authors performed the contrast helical CT for tumors on the maxillofacial regions, and reconstituted these data into the three-dimensional helical (spiral) CT angiography (CTA). Furthermore the conditions of photographing and the clinical significance of CTA were discussed. The subjects were 24 cases (including 13 of malignant tumors, 4 of benign tumors, 4 of inflammation and 3 of malformations), to which the contrast helical CT was performed transvenously. The photographing condition was set in principal to 140 kV of the tube voltage, 160 (200) mA of the tube current, 3 mm of the X-ray beam width, 3 mm/sec (pitch=1) of the turn-table moving speed. The relationship between the beam width and the pitch was determined by the phantom experiments. The scanning was carried out maximally for continuous 60 sec as the scanning time of a turn/sec. Of all cases, CTA visualized three-dimensionally vessels, but it was hard in the total carotid arteries and the internal-external carotid arteries. Authors analyzed the axial and the multiplanar reconstitution (MPR) images as the two-dimensional display, and the surface rendering (SR), the volume rendering and the maximum intensity projections (MIP) as the three-dimensional display. The axial and MPR image of the facial arteries and the lingual arteries as the branched vessels from the external carotid arteries were recognized easily. By SR, it was easily to understand the anatomical relationship among vessels, gnathic bone and cervical vertebrae, and by MIP sufficiently observe the concentration dependent calcification of the vessel walls. Three-dimensional CTA is very useful to get the three-dimensional visual information about the anatomical structures of the maxillofacial regions which is necessary for oral surgeons to plan the pre-operational strategies. (K.H.)

Accuracy of 16-detector Multislice Spiral Computed Tomography in the initial evaluation of dilated cardiomyopathy

International Nuclear Information System (INIS)

Cornily, Jean-Christophe; Gilard, Martine; Le Gal, Gregoire; Pennec, Pierre-Yves; Vinsonneau, Ulric; Blanc, Jean-Jacques; Mansourati, Jacques; Boschat, Jacques

2007-01-01

Background: Multislice Computed Tomography (MSCT) recently proved its accuracy in the detection of coronary artery disease (CAD). It can also give information about left ventricular function and venous network anatomy. We here sought to validate a MSCT-based strategy in the initial evaluation of patients with dilated cardiomyopathy (DCM). Methods: 36 patients with DCM underwent cardiac MSCT before conventional coronary angiography with ventriculography. We analysed arterial calcium score (Agatston score equivalent: ASE), coronary stenosis, left ventricular parameters and venous network. Results: The sensitivity of a MSCT-based strategy in detecting significant CAD was 100% and the specificity 80%. The positive and negative predictive values were respectively 67% and 100%. For ASE 1.000, conventional coronary angiography is mandatory due to MSCT's poor interest in such cases; when ASE <1.000, a contrast-enhanced MSCT may, when normal, replace coronary angiography

A Monte Carlo-based method to estimate radiation dose from spiral CT: from phantom testing to patient-specific models

International Nuclear Information System (INIS)

Jarry, G; De Marco, J J; Beifuss, U; Cagnon, C H; McNitt-Gray, M F

2003-01-01

The purpose of this work is to develop and test a method to estimate the relative and absolute absorbed radiation dose from axial and spiral CT scans using a Monte Carlo approach. Initial testing was done in phantoms and preliminary results were obtained from a standard mathematical anthropomorphic model (MIRD V) and voxelized patient data. To accomplish this we have modified a general purpose Monte Carlo transport code (MCNP4B) to simulate the CT x-ray source and movement, and then to calculate absorbed radiation dose in desired objects. The movement of the source in either axial or spiral modes was modelled explicitly while the CT system components were modelled using published information about x-ray spectra as well as information provided by the manufacturer. Simulations were performed for single axial scans using the head and body computed tomography dose index (CTDI) polymethylmethacrylate phantoms at both central and peripheral positions for all available beam energies and slice thicknesses. For comparison, corresponding physical measurements of CTDI in phantom were made with an ion chamber. To obtain absolute dose values, simulations and measurements were performed in air at the scanner isocentre for each beam energy. To extend the verification, the CT scanner model was applied to the MIRD V model and compared with published results using similar technical factors. After verification of the model, the generalized source was simulated and applied to voxelized models of patient anatomy. The simulated and measured absolute dose data in phantom agreed to within 2% for the head phantom and within 4% for the body phantom at 120 and 140 kVp; this extends to 8% for the head and 9% for the body phantom across all available beam energies and positions. For the head phantom, the simulated and measured absolute dose data agree to within 2% across all slice thicknesses at 120 kVp. Our results in the MIRD phantom agree within 11% of all the different organ dose values

The comparative study of various oral contrast media in 3D display of gastric lesions in spiral CT

International Nuclear Information System (INIS)

Wu Dong; Zhou Kangrong; Peng Weijun

2001-01-01

Objective: To optimize the oral contrast media in three-dimensional display of gastric lesions. Methods: 41 cases were randomly divided into 3 groups according to different oral contrast media administered: No. 1 air contrast group (n = 17), No. 2 fat emulsion group (n = 7) and No. 3 positive contrast group (n = 25). The 3D CT images were reconstructed using MPR, SSD, RaySum display and virtual endoscopic techniques, and compared with gastric endoscopy and/or conventional barium study. Results: The detectability of gastric lesions using fat emulsion and air contrast was 42.8%(3/7) and 80.0%(20/25), respectively, both were significantly lower than that using positive contrast (100%, 30/30) (x 2 = 19.22, P 2 = 6.60, P 2 = 17.04, P < 0.01). Conclusion: It is very important to choose the appropriate oral contrast media for 3D display of gastric lesions in spiral CT, the positive contrast agent is the optimal choice

Indication for and accuracy of CT and MRI of the temporomandibular joint

International Nuclear Information System (INIS)

Greess, H.; Anders, K.

2005-01-01

Recurrent pains of the temporomandibular joint represent a frequent symptom with numerous different causes. CT and MRI can reliably show the cause of these disorders and therefore have substituted conventional X-ray imaging. Modern multi-slice-CT (MSCT) allows for examination of the skull base including the mandible in a very short time with thinnest slice collimation (0.75 mm). With 2D- and 3D- reformations reconstructed out of this volume data set in parasagittal, coronal or any other arbitrary slice orientation excellent imaging of fractures and bony changes of arthrosis as well as benign and malignant tumors of the temporomandibular joint can be performed. MRI offers very good soft tissue contrast in order to visualize the intra-articular disc, the ligaments and muscles, as well the possibility to acquire cross sectional images in any user-defined orientation. MRI is the method of choice to diagnose 'internal derangement', particularly displacement of the intra-articular disc and inflammatory disease of the temporomandibular joint. The present paper will provide diagnostic strategies for the use of MSCT or MRI imaging concerning the different causes of disorders to the temporomandibular joint. (orig.)

Generalized multi-dimensional adaptive filtering for conventional and spiral single-slice, multi-slice, and cone-beam CT

International Nuclear Information System (INIS)

Kachelriess, Marc; Watzke, Oliver; Kalender, Willi A.

2001-01-01

In modern computed tomography (CT) there is a strong desire to reduce patient dose and/or to improve image quality by increasing spatial resolution and decreasing image noise. These are conflicting demands since increasing resolution at a constant noise level or decreasing noise at a constant resolution level implies a higher demand on x-ray power and an increase of patient dose. X-ray tube power is limited due to technical reasons. We therefore developed a generalized multi-dimensional adaptive filtering approach that applies nonlinear filters in up to three dimensions in the raw data domain. This new method differs from approaches in the literature since our nonlinear filters are applied not only in the detector row direction but also in the view and in the z-direction. This true three-dimensional filtering improves the quantum statistics of a measured projection value proportional to the third power of the filter size. Resolution tradeoffs are shared among these three dimensions and thus are considerably smaller as compared to one-dimensional smoothing approaches. Patient data of spiral and sequential single- and multi-slice CT scans as well as simulated spiral cone-beam data were processed to evaluate these new approaches. Image quality was assessed by evaluation of difference images, by measuring the image noise and the noise reduction, and by calculating the image resolution using point spread functions. The use of generalized adaptive filters helps to reduce image noise or, alternatively, patient dose. Image noise structures, typically along the direction of the highest attenuation, are effectively reduced. Noise reduction values of typically 30%-60% can be achieved in noncylindrical body regions like the shoulder. The loss in image resolution remains below 5% for all cases. In addition, the new method has a great potential to reduce metal artifacts, e.g., in the hip region

Spiral CT colonography in inflammatory bowel disease

International Nuclear Information System (INIS)

Tarjan, Zsolt; Zagoni, Tamas; Gyoerke, Tamas; Mester, Adam; Karlinger, Kinga; Mako, Erno K.

2000-01-01

Objective: Most of the studies on virtual colonoscopy are dealing with the role of detecting colorectal polyps or neoplasms. We have undertaken this study to evaluate the value of CT colonography in patients with colonic Crohn's disease. Methods and material: Five patients (three males, two females, 23-51 years, mean age 42 years) with known (4) or suspected (1) Crohn's disease of the colon underwent fiberoptic colonoscopy and CT colonography in the same day or during a 1-week period. The images were evaluated with the so called zoomed axial slice movie technique and in some regions intra- and extraluminal surface shaded and volume rendered images were generated on a separate workstation. The results were compared to those of a colonoscopy. Results: The final diagnosis was Crohn's disease in four patients and colitis ulcerosa in one. Total examination was possible by colonoscopy in two cases, and with CT colonography in all five cases. The wall of those segments severely affected by the disease were depicted by the axial CT scans to be thickened. The thick walled, segments with narrow lumen seen on CT colonography corresponded to the regions where colonoscopy was failed to pass. Air filled sinus tracts, thickening of the wall of the terminal ileum, loss of haustration pseudopolyps and deep ulcers were seen in CT colonography. Three dimensional (3D) endoluminal views demonstrated pseudopolyps similar to endoscopic images None of the colonoscopically reported shallow ulcerations or aphtoid ulcerations or granular mucosal surface were observed on 2- or 3D CT colonographic images. Conclusion: CT colonography by depicting colonic wall thickening seems to be a useful tool in the diagnosis of Crohn's colitis, which could be a single examination depicting the intraluminal, and transmural extent of the disease

Spiral scan long object reconstruction through PI line reconstruction

International Nuclear Information System (INIS)

Tam, K C; Hu, J; Sourbelle, K

2004-01-01

The response of a point object in a cone beam (CB) spiral scan is analysed. Based on the result, a reconstruction algorithm for long object imaging in spiral scan cone beam CT is developed. A region-of-interest (ROI) of the long object is scanned with a detector smaller than the ROI, and a portion of it can be reconstructed without contamination from overlaying materials. The top and bottom surfaces of the ROI are defined by two sets of PI lines near the two ends of the spiral path. With this novel definition of the top and bottom ROI surfaces and through the use of projective geometry, it is straightforward to partition the cone beam image into regions corresponding to projections of the ROI, the overlaying objects or both. This also simplifies computation at source positions near the spiral ends, and makes it possible to reduce radiation exposure near the spiral ends substantially through simple hardware collimation. Simulation results to validate the algorithm are presented

Multislice helical CT analysis of small-sized airway wall thickness in smokers and patients with bronchial asthma

International Nuclear Information System (INIS)

Sekimura, Kenshi; Ito, Harumasa; Nakamura, Yutaka; Kobayashi, Hitoshi; Oikawa, Hirobumi; Inoue, Hiroshi; Ehara, Shigeru; Yamauchi, Kohei

2010-01-01

There is accumulating evidence that airway remodeling, which contributes to airway narrowing, plays a role in the pathogenesis of bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD). Development of the multislice helical CT (MSCT) with improved spatial resolution has made it possible to obtain more precise imaging of small-sized airways. Small-sized airway wall-thickness was measured using the MSCT scan to analyze small-sized airways of smokers and BA patients, and examine the effects of a β 2 agonists on small-sized airway wall-thickness of BA patients. Thirty-six non-asthmatics who participated in the Health Check Program of Iwate Medical University and 25 patients with asthma were recruited. Amongst the 36 non-asthmatics were 20 healthy never-smokers and 15 smokers. The other 25 asthmatics were recruited from the outpatient clinic at Iwate Medical University. MSCT was performed and the right B10 bronchus was chosen for dimensional analysis. Airway wall thickness was expressed as a percentage of wall area (WA%). WA% of the 7 asthmatics before and 30 mim after procaterol (20μg) inspiration were compared. Small-sized airway wall thickness was significantly increased in smokers and patients with asthma compared to healthy never-smokers, when determined by MSCT. Both %V 50 and %V 25 had significant negative correlations with WA% among the healthy never-smokers and smoker population. Procaterol inspiration reduced WA% in the small airway of patients with asthma. Increase of small-sized airway thickness measured by MSCT scan may reflect peripheral obstructive lesions of smokers and BA patients. (author)

Anatomic variation in the origin of the main renal arteries: spiral CTA evaluation

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Beregi, J.P.; Willoteaux, S.; Remy-Jardin, M. [Department of Vascular Radiology, Hopital Cardiologique, 59 - Lille (France); Mauroy, B.; Francke, J.P. [Laboratoire d`Anatomie, Univ. de Lille (France); Mounier-Vehier, C. [Department of Hypertension and Internal Medicine, Hopital Cardiologique, Lille (France)

1999-09-01

The aim of this study was to provide quantitative data on the origin and trajectory of the main renal arteries using spiral CT angiography and arteriography. Normal renal artery anatomy was assessed on spiral CT angiography (axial transverse sections and shaded-surface-display reconstructions) in 100 patients referred for renal arteriography who had no significant renal artery stenosis. Two hundred major renal arteries were studied. The vast majority of right (88 %) and left (87 %) renal arteries originated between the lower third of the first lumbar vertebra and the lower border of the second lumbar vertebra. In 50 patients both ostia were at the same level; in the remaining 50 patients, the right ostium was located above the left in 37 patients. On the right, the angle of origin varied from -10 to + 55 (mean + 24 ). On the left, the angle of origin varied from + 30 to -55 (mean -11 ). Spiral CT angiography provides additional anatomic data, notably regarding the angle of origin of the renal arteries, that is potentially useful for planning interventional procedures. (orig.) With 4 figs., 19 refs.

Anatomic variation in the origin of the main renal arteries: spiral CTA evaluation

International Nuclear Information System (INIS)

Beregi, J.P.; Willoteaux, S.; Remy-Jardin, M.; Mauroy, B.; Francke, J.P.; Mounier-Vehier, C.

1999-01-01

The aim of this study was to provide quantitative data on the origin and trajectory of the main renal arteries using spiral CT angiography and arteriography. Normal renal artery anatomy was assessed on spiral CT angiography (axial transverse sections and shaded-surface-display reconstructions) in 100 patients referred for renal arteriography who had no significant renal artery stenosis. Two hundred major renal arteries were studied. The vast majority of right (88 %) and left (87 %) renal arteries originated between the lower third of the first lumbar vertebra and the lower border of the second lumbar vertebra. In 50 patients both ostia were at the same level; in the remaining 50 patients, the right ostium was located above the left in 37 patients. On the right, the angle of origin varied from -10 to + 55 (mean + 24 ). On the left, the angle of origin varied from + 30 to -55 (mean -11 ). Spiral CT angiography provides additional anatomic data, notably regarding the angle of origin of the renal arteries, that is potentially useful for planning interventional procedures. (orig.)

Role of CT scan in diagnosis of acute appendicitis

International Nuclear Information System (INIS)

Salem, O.A.; Khasawneh, M.

2007-01-01

To evaluate the diagnostic accuracy of the spiral-CT in patients with clinically suspected acute appendicitis. A total of 124 patients referred for CT scan with suspected appendicitis between January 2005 and October 2006 were assessed for the appendiceal size and the presence of signs of appendicitis. The findings were correlated with surgical histopathology. CT scan had a sensitivity of 95 percent and a specifity of 93 percent and an overall accuracy of 92 percent. The use of spiral CT in patients with equivocal clinical presentation suspected of having acute appendicitis can lead to significant improvement in the preoperative diagnosis. (author)

Multislice CT coronary angiography: evaluation of an automatic vessel detection tool

International Nuclear Information System (INIS)

Dewey, M.; Schnapauff, D.; Lembcke, A.; Hamm, B.; Rogalla, P.; Laule, M.; Borges, A.C.; Rutsch, W.

2004-01-01

Purpose: To investigate the potential of a new detection tool for multisliceCT (MSCT) coronary angiography with automatic display of curved multiplanar reformations and orthogonal cross-sections. Materials and Methods: Thirty-five patients were consecutively enrolled in a prospective intention-to-diagnose study and examined using a MSCT scanner with 16 x 0.5 mm detector collimation and 400 ms gantry rotation time (Aquilion, Toshiba). A multisegment algorithm using up to four segments was applied for ECG-gated reconstruction. Automatic and manual detection of coronary arteries was conducted using the coronary artery CT protocol of a workstation (Vitrea 2, Version 3.3, Vital Images) to detect significant stenoses (≥50%) in all segments of ≥1.5 mm in diameter. Each detection tool was used by one reader who was blinded to the results of the other detection method and the results of conventional coronary angiography. Results: The overall sensitivity, specificity, nondiagnostic rate, and accuracy of the automatic and manual approach were 90 vs. 94%, 89 vs. 84%, 6 vs. 6%, and 89 vs. 88%, respectively (p=n.s.). The vessel length detected with the automatic and manual approach were highly correlated for the left main/left anterior descending (143±30 vs. 146±24 mm, r=0.923, p [de

Multiphasic helical CT of hepatocellular carcinoma. Evaluation after chemoembolization; Tomografia Computerizzata spirale multifasica dell'epatocarcinoma. Valutazione dopo chemioembolizzazione

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Catalano, O.; Esposito, M.; Sandomenico, F.; Siani, A. [Ospedale S. Maria delle Grazie, Pozzuoli, NA (Italy). Servizio di Radiologia; Nunziata, A. [Ospedale S. Maria delle Grazie, Naples (Italy). Area di Diagnostica per Immagini

2000-06-01

The main purpose of this work is to report the personal experience with addition of contrast-enhanced multiphase helical CT to unenhanced CT (Lipiodol CT) in the evaluation of patients with hepatocellular carcinoma treated with chemoembolization and to analyze the present role of oily agent CT. It has been retrospectively reviewed the examinations of 42 consecutive patients submitted to global chemoembolization over a 2-year period. CT was performed 18-30 days after the treatment. The Lipiodol CT study was carried out with volume acquisitions. It has been considered as nodules all well-defined areas with dense oily agent uptake; uptake itself was classified as: 0=absent, I=lower than 10% of the tumor volume; II=lower than 50%, III=50%, IV=homogeneous. Contrast-enhanced helical CT was performed with the 2-phase technique in 28 patients and with the 3-phase technique in 14; it has been considered as nodules all well-defined and relatively homogeneous areas with hyper attenuation in the arterial phase and hypo-iso attenuation in the portal and/or delayed phase, or with hypo-iso attenuation in the arterial phase and in the portal and/or delayed phase. Lipiodol CT permitted to recognize 65 nodules (1-5/patient, mean 1.5), namely 15 grade I, 21 grade II, 20 grade III and 9 grade IV. Multiphase CT identified 6 additional nodules in 5 patients, 5 hyper vascular and 1 hypo vascular, and better assessed the correct morphology and volume of grade I nodules. Only 4 of 6 nodules missed on Lipiodol CT showed oily agent uptake after a new chemo embolization session. Moreover after retreatment, carried out in 6 of 9 patients with grade I uptake (11 nodules in all), it has been found persistence of the grade I pattern in 5 nodules, grade II in 5, and grade III in 1. Lipiodol CT may miss liver nodules and underestimate the volume of nodules with poor uptake. Though Lipiodol CT should still be considered slightly more sensitive than multiphase CT, in the general opinion this

Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications

NARCIS (Netherlands)

Loubele, M.; Bogaerts, R.; van Dijck, E.; Pauwels, R.; Vanheusden, S.; Seutens, P.; Marchal, G.; Sanderink, G.; Jacobs, R.

2009-01-01

Objectives: To compare the effective dose levels of cone beam computed tomography (CBCT) for maxillofacial applications with those of multi-slice computed tomography (MSCT). Study design: The effective doses of 3 CBCT scanners were estimated (Accuitomo 3D®, i-CAT®, and NewTom 3G®) and compared to

The CT signs of intestinal volvulus

International Nuclear Information System (INIS)

Ji Jiansong; Wang Zufei; Xu Zhaolong; Lv Guijian; Xu Min; Zhao Zhongwei; Su Jinliang; Zhou Limin

2005-01-01

Objective: To improve the accuracy rate of spiral CT diagnosing intestinal volvulus. Methods: To analysis the CT findings of 9 cases of intestinal volvulus proved by operation, the main reconstruction techniques were multiplanar reformation (MPR) and sliding thin-slab maximum intensity projection (STS-MIP). Results: All the 9 cases were diagnosed accurately, the main signs were 'whirlpool' of intestine (6 cases) and vessels (9 cases),'target loop' (2 cases),'beak'(6 cases). Conclusion: 'Whirlpool' of vessels is a specific sign to diagnose intestinal volvulus, 'target loop', reduced enhancement of intestinal wall and ascites are the reliable signs to strangulated intestinal obstruction. Spiral CT and reconstructions have important value to diagnose the intestinal volvulus. (authors)

Electron-beam CT coronary angiography in the patients with high heart rate arrhythmia or pacemaker

International Nuclear Information System (INIS)

Dong Zhi; Zhu Jiemin; Liu Zhe; Liu Junbo; Li Youjie; Qi Ji

2006-01-01

Objective: To report the clinical applicability of coronary angiography for patients with high heart rate, arrhythmia or cardiac pacing using the new-generation of electron-beam CT (e-Speed). Methods: EBCT (GE e-Speed) coronary angiography was performed in 36 eases (male 27, female 9, mean age 58), including the heart rate more than 90 bpm in 20 patients, frequent ectopic beats in 11 cases, implantation of cardiac pacemaker in 4 patients and the unacceptable MSCT image quality due to variability of interscan heart rate (from 82 bpm to 104 bpm) in 1 case. After volume data set was acquired using spiral mode with prospective ECG-gating, the reconstructions of MIP, CPR, VR and Cine were performed. The VR quality was evaluated using a five-point scale. Results: The quality of coronary imaging in all of 36 cases were acceptable. The total visualization rate of coronary artery branches was 80.0%. Left main, left anterior artery and right coronary artery were visualized in all patients and in 94.3% of all cases circumflex artery were visible. Conclusion: EBCT (e-Speed) is applicable in noninvasive coronary angiography for patients with high heart rate, arrhythmia or implanted cardiac pacemaker', and this examination can obtain satisfied diagnosis. (authors)

Intravenous spiral CT angiography for assessment before orthotopic liver transplantation: Comparison between tomography, MIP, 3-dimensional surface imaging and intraarterial DSA

International Nuclear Information System (INIS)

Hidajat, N.; Vogl, T.J.; Moeller, M.; Bechstein, W.O.; Felix, R.

1996-01-01

Purpose: To analyse the efficacy of intravenous spiral CT angiography (SCTA) for the evaluation before orthotopic liver transplantation (oLT) compared with DSA. Methods: Spiral CT was performed on 31 potential recipients of a liver graft in order to examine hepatic vessels, coeliac axis, splenic artery and superior mesenteric artery. The arterial vessels were reconstructed in 'Maximum Intensity Projection (MIP)' and 'Shaded Surface Display (SSD)'-technique. The axial images, MIP and SSD were compared in 25 patients with DSA with regard to the visualisation of the vascular anatomy, detectability of stenosis and vascular diameters. Results: The type of arterial liver supply could be determined via SCTA in all patients. Stenosis of the coeliac axis was seen in ten patients on the DSA, MIP and SSD and in eight patients on the axial images. Occlusion of the hepatic artery was clearly visualised in two patients on the DSA, axial images and MIP and in one patient on the SSD. There was no false positive diagnosis with SCTA. SSD was seen as the best technique to visualise the vessels without overshadowing. There were no significant differences between the diamters measured from the axial images, MIP and SSD images in transversal direction and the DSA images (p>0.05). Conclusion: SCTA is a greatly promising method for the imaging of vessels supplying the liver before oLT, and may convey more diagnostic information than DSA. (orig.) [de

Multislice CT of the auditory ossicles and ossicular ligaments. Delineation of normal anatomy and diagnosis of congenital anomaly

International Nuclear Information System (INIS)

Matsumoto, Shigeru; Tozaki, Hiromitu; Miyazaki, Hidemi

2001-01-01

By using four detector rows with 0.5 mm collimation, high resolution isotropic voxel data throughout the middle ear can be obtained with Multislice Helical CT (MSCT). The purpose of this study is to evaluate the usefulness of MSCT in demonstrating the auditory ossicles and ossicular ligaments and in the diagnosis of congenital ossicular anomalies. Thirty normal middle ears and 23 ear of 20 patients with suspicious congenital ossicular anomalies were examined. Axial images and multiplanar images were reconstructed. In the normal group, the images were evaluated based on scores for the visualization of the anatomical structure of the auditory ossicles and ossicular ligaments. In the group with anomalies, the findings suggesting ossicular anomalies were referenced and the prevalence was conjectured. Visualization of the auditory ossicles and ossicular ligaments was 98.3%-100% and 78.3%-100%, respectively. Congenital ossicular anomalies were detected in 20 ears (87.0%). MSCT is an accurate method for demonstrating minute and complicated 3D structures of the middle ear, and is found to be a technique of choice for diagnosis of ossicular anomalies. (author)

Double prospectively ECG-triggered high-pitch spiral acquisition for CT coronary angiography: Initial experience

International Nuclear Information System (INIS)

Wang, Q.; Qin, J.; He, B.; Zhou, Y.; Yang, J.-J.; Hou, X.-L.; Yang, X.-B.; Chen, J.-H.; Chen, Y.-D.

2013-01-01

Aim: To evaluate the feasibility of double prospectively electrocardiogram (ECG)-triggered high-pitch spiral acquisition mode (double high-pitch mode) for coronary computed tomography angiography (CTCA). Materials and methods: One hundred and forty-nine consecutive patients [40 women, 109 men; mean age 58.2 ± 9.2 years; sinus rhythm ≤70 beats/min (bpm) after pre-medication, body weight ≤100 kg] were enrolled for CTCA examinations using a dual-source CT system with 2 × 128 × 0.6 mm collimation, 0.28 s rotation time, and a pitch of 3.4. Double high-pitch mode was prospectively triggered first at 60% and later at 30% of the R–R interval within two cardiac cycles. Image quality was evaluated using a four-point scale (1 = excellent, 4 = non-assessable). Results: From 2085 coronary artery segments, 86.4% (1802/2085) were rated as having a score of 1, 12.3% (257/2085) as score of 2, 1.2% (26/2085) as score of 3, and none were rated as “non-assessable”. The average image quality score was 1.15 ± 0.26 on a per-segment basis. The effective dose was calculated by multiplying the coefficient factor of 0.028 by the dose–length product (DLP); the mean effective dose was 3.5 ± 0.8 mSv (range 1.7–7.6 mSv). The total dosage of contrast medium was 78.7 ± 2.9 ml. Conclusion: Double prospectively ECG-triggered high-pitch spiral acquisition mode provides good image quality with an average effective dose of less than 5 mSv in patients with a heart rate ≤70 bpm

Dual-phase CT of the liver and the pancreas

International Nuclear Information System (INIS)

Dragiyski, B.; Velkova, K.

2004-01-01

This survey covers the introduction of Spiral CT in the diagnostics of lesions of the liver and the pancreas. It describes the possibility to display separate images of the arterial and portal-venous phases of saturation of the liver and the pancreas. It also considers the indications leading to use of dual-phase Spiral CT on the liver and the pancreas. We trace the development of the dual-phase Spiral CT in visualization of the structure of blood vessels in the area of liver and pancreas. The survey puts forward the potential of the dual-phase method to improve the diagnostics and description of many primary and secondary malignant tumors of the liver and the pancreas, their differentiation from benign neoplasm, as well as the existing problems and some controversial aspects of its application

MSCT follow-up in malignant lymphoma. Comparison of manual linear measurements with semi-automated lymph node analysis for therapy response classification

International Nuclear Information System (INIS)

Wessling, J.; Puesken, M.; Kohlhase, N.; Persigehl, T.; Mesters, R.; Heindel, W.; Buerke, B.; Koch, R.

2012-01-01

Purpose: Assignment of semi-automated lymph node analysis compared to manual measurements for therapy response classification of malignant lymphoma in MSCT. Materials and Methods: MSCT scans of 63 malignant lymphoma patients before and after 2 cycles of chemotherapy (307 target lymph nodes) were evaluated. The long axis diameter (LAD), short axis diameter (SAD) and bi-dimensional WHO were determined manually and semi-automatically. The time for manual and semi-automatic segmentation was evaluated. The ref. standard response was defined as the mean relative change across all manual and semi-automatic measurements (mean manual/semi-automatic LAD, SAD, semi-automatic volume). Statistical analysis encompassed t-test and McNemar's test for clustered data. Results: Response classification per lymph node revealed semi-automated volumetry and bi-dimensional WHO to be significantly more accurate than manual linear metric measurements. Response classification per patient based on RECIST revealed more patients to be correctly classified by semi-automatic measurements, e.g. 96.0 %/92.9 % (WHO bi-dimensional/volume) compared to 85.7/84.1 % for manual LAD and SAD, respectively (mean reduction in misclassified patients of 9.95 %). Considering the use of correction tools, the time expenditure for lymph node segmentation (29.7 ± 17.4 sec) was the same as with the manual approach (29.1 ± 14.5 sec). Conclusion: Semi-automatically derived 'lymph node volume' and 'bi-dimensional WHO' significantly reduce the number of misclassified patients in the CT follow-up of malignant lymphoma by at least 10 %. However, lymph node volumetry does not outperform bi-dimensional WHO. (orig.)

MSCT follow-up in malignant lymphoma. Comparison of manual linear measurements with semi-automated lymph node analysis for therapy response classification

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Wessling, J.; Puesken, M.; Kohlhase, N.; Persigehl, T.; Mesters, R.; Heindel, W.; Buerke, B. [Muenster Univ. (Germany). Dept. of Clinical Radiology; Koch, R. [Muenster Univ. (Germany). Inst. of Biostatistics and Clinical Research

2012-09-15

Purpose: Assignment of semi-automated lymph node analysis compared to manual measurements for therapy response classification of malignant lymphoma in MSCT. Materials and Methods: MSCT scans of 63 malignant lymphoma patients before and after 2 cycles of chemotherapy (307 target lymph nodes) were evaluated. The long axis diameter (LAD), short axis diameter (SAD) and bi-dimensional WHO were determined manually and semi-automatically. The time for manual and semi-automatic segmentation was evaluated. The ref. standard response was defined as the mean relative change across all manual and semi-automatic measurements (mean manual/semi-automatic LAD, SAD, semi-automatic volume). Statistical analysis encompassed t-test and McNemar's test for clustered data. Results: Response classification per lymph node revealed semi-automated volumetry and bi-dimensional WHO to be significantly more accurate than manual linear metric measurements. Response classification per patient based on RECIST revealed more patients to be correctly classified by semi-automatic measurements, e.g. 96.0 %/92.9 % (WHO bi-dimensional/volume) compared to 85.7/84.1 % for manual LAD and SAD, respectively (mean reduction in misclassified patients of 9.95 %). Considering the use of correction tools, the time expenditure for lymph node segmentation (29.7 {+-} 17.4 sec) was the same as with the manual approach (29.1 {+-} 14.5 sec). Conclusion: Semi-automatically derived 'lymph node volume' and 'bi-dimensional WHO' significantly reduce the number of misclassified patients in the CT follow-up of malignant lymphoma by at least 10 %. However, lymph node volumetry does not outperform bi-dimensional WHO. (orig.)

Detection of pulmonary metastases with pathological correlation: effect of breathing on the accuracy of spiral CT. Editor's note

International Nuclear Information System (INIS)

Coakley, F.V.; Cohen, M.D.; Waters, D.J.; Davis, M.M.; Karmazyn, B.; Gonin, R.; Hanna, M.P.

1997-01-01

Background. CT of the chest for suspected pulmonary metastases in adults is generally performed using a breath-hold technique. The results may not be applicable to young children in whom breath-holding may be impossible. Objective. Determine the effect of breathing on the accuracy of pulmonary metastasis detection by spiral CT (SCT). Materials and methods. Prior to euthanasia four anesthetized dogs with metastatic osteosarcoma underwent SCT with a collimation of 5 mm and a pitch of 2, during both induced breath-hold and normal quiet breathing. Images were reconstructed as contiguous 5-mm slices. Macroscopically evident metastases were noted at postmortem. Hard-copy SCT images were reviewed by ten radiologists, each of whom circled all suspected metastases. SCT images were compared with postmortem results to determine true and false positives. Results. The pathologist identified 132 macroscopically evident pulmonary metastases. For metastasis detection, there was no significant difference between breath-hold SCT and breathing SCT. Conclusion. In our animal model, SCT can be performed during normal resting breathing without significant loss of accuracy in the detection of pulmonary metastases. (orig.). With 3 tabs

Value of MR imaging after CT in patients with focal hepatic lesion

International Nuclear Information System (INIS)

Kim, Kyeong Ah; Lim, Jae Hoon; Choi, Sang Hee; Lee, Soon Jin; Paik, Chul H.; Cho, Jae Min

1999-01-01

To determine the usefulness of magnetic resonance imaging (MRI) after computed tomography (CT) in patients with focal hepatic lesion. We evaluated 100 patients with 103 focal hepatic lesions. The diagnosis of each lesion was made pathologically (n=19), or radiologically and clinically (n=84), and the findings were as follows : hemangioma (n=53), hepatocellular carcinoma (n=17), metastasis (n=10), cyst (n=5), regenerative nodule (n=3), and adenomatous hyperplasia (n=3). The patients underwent conventional CT (n=25), two-phase spiral CT (n=17) or three-phase spiral CT (n=61). MRI was performed using conventional T1- and T2-weighted imaging and dynamic contrast enhancement. The value of MRI after CT was assigned to one of four grades, according to the consensus of three radiologists : grade I (decisive), grade II (helpful), grade III (not additional), or grade IV (confused). The outcome of MRI of 103 lesions was grade I in 14 cases(14%), II in 34 (33%), III in 49 (48%), and IV in 6 (6%). MRI was not helpful (grade III or IV) in 40% (10/25), 47% (8/17), and 61%(31/61) of lesions after conventional, two-phase spiral, and three-phase spiral CT, respectively. Grade III or IV lesions were present in 45% of hemangiomas (24/53), 59% of hepatocellular carcinomas (10/17), and 80% of cases in which metastasis had occurred(8/10). MRI after CT in patients with focal hepatic lesion was helpful in less than half of all cases. It was particularly valuable for patients who did not undergo three-phase spiral CT and in whom hemangioma was suspected

Clinical validation of a dose reduction study in paediatric abdomen MSCT scanning

International Nuclear Information System (INIS)

Ciccarone, A.; Fonda, C.; Zatelli, Giovanna; Mazzocchi, S.

2008-01-01

Full text: In our previous work an individual dose adaptation in abdomen of paediatric patients has been showed at the Meyer children hospital of Florence. For each kV really feasible in our MSCT scanner, a table of mAs versus abdomen thickness and width ratio has been developed only on the basis of water cylinder phantoms. The choice of the water arise by the fact that in pediatric patient the quantity of water inside the body is major than that of adult. In this way a reduction dose has showed with respect to the ordinary paediatric scanning protocol in use before and the same image quality has been preserved in the case of an optimized CT scanning technique of a standard adult patient of height 175 cm and weight 70 kg. However these results were only theoretical because relied on water phantoms. Now this work concerns the clinical validation of our dose reduction study on phantoms. So 50 examinations were acquired with the dose reduction scanning technique and scored randomly, without knowing weight and height of patient by three radiologists. These scores were compared with that of other 50 abdomen examination before dose reduction study. The scores refers to the noise perceived by radiologist and to the diagnostic quality of radiograph. As last, a score on the low contrast tissue separation between muscle and fat and a score on visibility of structure therein have been asked to the radiologists. The same work has concerned the abdomen examinations with iodine contrast medium. In this study the score of each radiographs has been catalogued in four range of age, 0 - 1; 1 - 3; 3 - 8; 8 - 13 years. Aligned rank and Wilcoxon's signed rank tests were used for statistical analyses. The table of modulating mAs with respect to the size of patient obtained with only water phantom study has been revised so that none reduced detection in low-visibility structures like fat or muscle or liver was evident. Nevertheless a reduction in CTDI of 30 % has been reached in our new

Correlation between the Quantifiable Parameters of Whole Solitary Pulmonary Nodules Perfusion Imaging Derived with Dynamic CT and Nodules Size

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Shiyuan LIU

2009-05-01

Full Text Available Background and objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. The blood flow patterns of the biggest single SPNs level has been studied. This assessment may be only a limited sample of the entire region of interest (ROI and is unrepresentative of the SPNs as a volume. Ideally, SPNs volume perfusion should be measured. The aim of this study is to evaluate the correlation between the quantifiableparameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size. Methods Sixty-five patients with SPNs (diameter≤3 cm; 42 malignant; 12 active inflammatory; 11 benign underwent multi-location dynamic contrast material-enhanced serial CT scanning mode with stable table were performed; The mean values of valid sections were calculated, as the quantifiable parameters of volume SPNs perfusion imaging derived with16-slice spiral CT and 64-slice spiral CT. The correlation between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size were assessed by means of linear regression analysis. Results No significant correlations were found between the nodules size and each of the peak height (PHSPN (32.15 Hu±14.55 Hu，ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio(13.20±6.18%, perfusion(PSPN (29.79±19.12 mLmin-1100 g-1 and mean transit time (12.95±6.53 s (r =0.081, P =0.419; r =0.089, P =0.487; r =0.167, P =0.077; r =0.023, P =0.880. Conclusion No significant correlations were found between the quantifiable parameters of SPNs volume perfusion imaging derived with 16-slice spiral CT and 64-slice spiral CT and nodules size.

Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

Science.gov (United States)

Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

2006-01-01

In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution. RSNA, 2006

Evaluation of image quality and dose in thoracic spiral CT examination in patients with pulmonary carcinoma. Preliminary results

International Nuclear Information System (INIS)

Moran-Blanco, L. M.; Rodriguez-Gonzalez, R.; Calzado-Cantera, A.; Arenas de Pablo, A.; Baeza-Trujillo, M.; Cuevas-Ibanez, A.; Garcia-Castano, B.; Gomez-Leon, N.; Turrero-Nogues, A.; Moran-Penco, P.

2002-01-01

We have applied criteria for CT quality defined in the European Guidelines to a samples of thoracic CT examinations for the indication of pulmonary carcinoma of 5 institutions of the Community of Madrid that have spiral CT equipment. The selected examinations have been evaluated independently by five radiologists to determine the degree of adherence to the quality criteria for image defined in the Guidelines s for examinations of general thorax. Dosimetric measurements carried out in parallel have served to estimate the values of CT (CTDI w ) dose indices, dose-length product (DLP) and effective dose for every patient. The result show a high global adherence to the quality criteria (96%), with averages per institution being between 94% (in two institutions) and 98% (in three institutions). There are 10 of 16 criteria that are adhered to in all examinations of the sample: those which are not adhered to systematically are: two of visualization (1.1 and 1.4), with 92-96% fulfillment, and four of critical reproduction (2.6; 2.8; 2.9 and 2.10), with percentages of adherence between 91% and 96%. The average CTDI w values per institution are in the interval 12.9-19.1 mGy; those of DLP between 263 and 577 mGy cm and those of effective dose between 4.2 and 9.2 mSv. The DLP-image quality correlation in institutions with the best image quality was null in two of them and direct and moderate in the third. In both institutions with the poorest image: (Author) 20 refs

Spiral CT aortography: an efficient technique for the diagnosis of traumatic aortic injury

International Nuclear Information System (INIS)

Wicky, S.; Capasso, P.; Meuli, R.; Schnyder, P.; Fischer, A.; Segesser, L. von

1998-01-01

The objective of this study was to assess the efficiency of spiral CT (SCT) aortography for diagnosing acute aortic lesions in blunt thoracic trauma patients. Between October 1992 and June 1997, 487 SCT scans of the chest were performed on blunt thoracic trauma patients. To assess aortic injury, the following SCT criteria were considered: hemomediastinum, peri-aortic hematoma, irregular aspect of the aortic wall, aortic pseudodiverticulum, intimal flap and traumatic dissection. Aortic injury was diagnosed on 14 SCT examinations (2.9 %), five of the patients having had an additional digital aortography that confirmed the aortic trauma. Twelve subjects underwent surgical repair of the thoracic aorta, which in all but one case confirmed the aortic injury. Two patients died before surgery from severe brain lesions. The aortic blunt lesions were confirmed at autopsy. According to the follow-up of the other 473 patients, we are aware of no false-negative SCT examination. Our limited series shows a sensitivity of 100 % and specificity of 99.8 % of SCT aortography in the diagnosis of aortic injury. It is concluded that SCT aortagraphy is an accurate diagnostic method for the assessment of aortic injury in blunt thoracic trauma patients. (orig.)

Contrast-enhanced multislice pneumo-CT-cystography in the evaluation of urinary bladder neoplasms

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Scardapane, Arnaldo [Institute of Diagnostic Radiology, University Hospital ' Policlinico' , Bari (Italy)], E-mail: scardapane@aruba.it; Pagliarulo, Vincenzo [Institute of Urology, University Hospital ' Policlinico' , Bari (Italy); Ianora, Amato A. Stabile [Institute of Diagnostic Radiology, University Hospital ' Policlinico' , Bari (Italy); Pagliarulo, Arcangelo [Institute of Urology, University Hospital ' Policlinico' , Bari (Italy); Angelelli, Giuseppe [Institute of Diagnostic Radiology, University Hospital ' Policlinico' , Bari (Italy)

2008-05-15

Purpose: To evaluate the accuracy of contrast-enhanced multislice CT (MSCT) in the study of urothelial tumors after distension of the bladder with air. Materials and methods: We evaluated 43 consecutive patients with endoscopically proven bladder lesions. After air distension of the bladder, unenhanced pelvic and enhanced abdomino-pelvic scans were obtained with the following protocol: thickness 2.5 mm x 4 mm, increment 1 mm, scan delay 40'' and 7-10 min. For each patient we considered the number, size, aspect (papillary or sessile) and contrast enhancement of lesions. Ureteral involvement and the presence of synchronous lesions in the excretory scan were also evaluated. MPR and virtual endoscopy images were reviewed in all cases. Results: Bladder lesions were visualized in 39/43 cases. Compared to conventional cystoscopy, MSCT recognized single lesions in 31/33 patients, two lesions in 4/6, three in 2/2 and more than five foci in 2/2 patients. A papillary aspect was described in 44 cases while 11 lesions were sessile. Conventional Cystoscopy recognized six more lesions as compared with MSCT (four flat and two small papillary lesions). The detection rate for protruding lesions was 100% (52/52) for lesions > 5 mm and 60% (3/5%) for lesions < 5 mm. In four patients hydronephrosis was present, while in one case a synchronous lesion was evident in the renal pelvis. Conclusion: Contrast-enhanced MSCT with air distension of the urinary bladder is a safe and complete investigation to evaluate the local stage of bladder cancer and to evaluate the ureteral extension of the tumor, as well as the presence of synchronous lesions.

[Establishment of a 3D finite element model of human skull using MSCT images and mimics software].

Science.gov (United States)

Huang, Ping; Li, Zheng-dong; Shao, Yu; Zou, Dong-hua; Liu, Ning-guo; Li, Li; Chen, Yuan-yuan; Wan, Lei; Chen, Yi-jiu

2011-02-01

To establish a human 3D finite element skull model, and to explore its value in biomechanics analysis. The cadaveric head was scanned and then 3D skull model was created using Mimics software based on 2D CT axial images. The 3D skull model was optimized by preprocessor along with creation of the surface and volume meshes. The stress changes, after the head was struck by an object or the head hit the ground directly, were analyzed using ANSYS software. The original 3D skull model showed a large number of triangles with a poor quality and high similarity with the real head, while the optimized model showed high quality surface and volume meshes with a small number of triangles comparatively. The model could show the local and global stress changes effectively. The human 3D skull model can be established using MSCT and Mimics software and provides a good finite element model for biomechanics analysis. This model may also provide a base for the study of head stress changes following different forces.

Detection of pulmonary metastases with pathological correlation: effect of breathing on the accuracy of spiral CT. Editor`s note

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Coakley, F.V. [Abdominal Imaging Section, Department of Radiology, University of California, San Francisco, CA (United States); Cohen, M.D. [Department of Radiology, Riley Hospital for Children, Indianapolis, IN (United States); Waters, D.J. [Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN (United States); Davis, M.M. [Department of Pathology, Riley Hospital for Children, Indianapolis, IN (United States); Karmazyn, B. [Department of Radiology, Riley Hospital for Children, Indianapolis, IN (United States); Gonin, R. [Division of Biostatistics, Department of Medicine, Riley Hospital for Children, Indianapolis, IN (United States); Hanna, M.P. [Division of Biostatistics, Department of Medicine, Riley Hospital for Children, Indianapolis, IN (United States)

1997-07-01

Background. CT of the chest for suspected pulmonary metastases in adults is generally performed using a breath-hold technique. The results may not be applicable to young children in whom breath-holding may be impossible. Objective. Determine the effect of breathing on the accuracy of pulmonary metastasis detection by spiral CT (SCT). Materials and methods. Prior to euthanasia four anesthetized dogs with metastatic osteosarcoma underwent SCT with a collimation of 5 mm and a pitch of 2, during both induced breath-hold and normal quiet breathing. Images were reconstructed as contiguous 5-mm slices. Macroscopically evident metastases were noted at postmortem. Hard-copy SCT images were reviewed by ten radiologists, each of whom circled all suspected metastases. SCT images were compared with postmortem results to determine true and false positives. Results. The pathologist identified 132 macroscopically evident pulmonary metastases. For metastasis detection, there was no significant difference between breath-hold SCT and breathing SCT. Conclusion. In our animal model, SCT can be performed during normal resting breathing without significant loss of accuracy in the detection of pulmonary metastases. (orig.). With 3 tabs.

Correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size

Directory of Open Access Journals (Sweden)

Chenshi ZHANG

2008-02-01

Full Text Available Background and Objective The solitary pulmonary nodules (SPNs is one of the most common findings on chest radiographs. It becomes possible to provide more accurately quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs with multi-slice spiral computed tomography (MSCT. The aim of this study is to evaluate the correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size. Methods 68 patients with maliagnant solitary pulmonary nodules (SPNs (diameter <=4 cmunderwent multi-location dynamic contrast material-enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4mL/s by an autoinjector, 4*5mm or 4*2.5mm scanning mode with stable table were performed. serial CT. Precontrast and postcontrast attenuation on every scan was recorded. Perfusion (PSPN, peak height (PHSPNratio of peak height of the SPN to that of the aorta (SPN-to-A ratioand mean transit time(MTT were calculated. The correlation between the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules and tumor size were assessed by means of linear regression analysis. Results No significant correlations were found between the tumor size and each of the peak height (PHSPN ratio of peak height of the SPN to that of the aorta (SPN-to-A ratio perfusion(PSPNand mean transit time (r=0.18, P=0.14; r=0.20,P=0.09; r=0.01, P=0.95; r=0.01, P=0.93. Conclusion No significant correlation is found between the tumor size and each of the quantifiable parameters of blood flow pattern derived with dynamic CT in maliagnant solitary pulmonary nodules.

Traumatic injuries: organization and ergonomics of imaging in the emergency environment

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Wintermark, Max; Schnyder, Pierre [Department of Diagnostic and Interventional Radiology, University Hospital, Lausanne (Switzerland); Poletti, Pierre-Alexandre; Becker, Christoph D. [Department of Diagnostic and Interventional Radiology, University Hospital, Geneva (Switzerland)

2002-05-01

Management of trauma patients relies on a simple but obvious concept: Time is life. This is a challenge to the emergency radiologist in his evaluation of the radiological admission survey of severe trauma patients, since the latter need a quick and thorough survey of craniocerebral, cervical, thoracic, abdominal, and limb lesions. This article reviews the architectural design and the management strategies required to fulfill this purpose. Whereas plain films and ultrasonography have precise but limited indications, multislice spiral CT (MSCT) shows an increasingly preponderant role in the imaging evaluation of trauma patients, as demonstrated through three examples (aortic, spine, and craniocerebral trauma). Multislice CT affords a comprehensive assessment of trauma patients' injuries and allows for their categorization according to the severity of traumatic lesions. With respect to the MSCT data volume, the emergency radiologists have to modify the strategies in their examination reading and result transmission, with a growing role attributed to two- and three-dimensional reconstructions. The emergency radiologist's role is thus of prime importance in the management of trauma patients, and this all the more so since development of interventional radiology affords therapeutic procedures alternative to surgery. Trauma radiology and emergency radiology on the whole will assert themselves as consistent and thorough areas of subspecialization. (orig.)

Traumatic injuries: organization and ergonomics of imaging in the emergency environment

International Nuclear Information System (INIS)

Wintermark, Max; Schnyder, Pierre; Poletti, Pierre-Alexandre; Becker, Christoph D.

2002-01-01

Management of trauma patients relies on a simple but obvious concept: Time is life. This is a challenge to the emergency radiologist in his evaluation of the radiological admission survey of severe trauma patients, since the latter need a quick and thorough survey of craniocerebral, cervical, thoracic, abdominal, and limb lesions. This article reviews the architectural design and the management strategies required to fulfill this purpose. Whereas plain films and ultrasonography have precise but limited indications, multislice spiral CT (MSCT) shows an increasingly preponderant role in the imaging evaluation of trauma patients, as demonstrated through three examples (aortic, spine, and craniocerebral trauma). Multislice CT affords a comprehensive assessment of trauma patients' injuries and allows for their categorization according to the severity of traumatic lesions. With respect to the MSCT data volume, the emergency radiologists have to modify the strategies in their examination reading and result transmission, with a growing role attributed to two- and three-dimensional reconstructions. The emergency radiologist's role is thus of prime importance in the management of trauma patients, and this all the more so since development of interventional radiology affords therapeutic procedures alternative to surgery. Trauma radiology and emergency radiology on the whole will assert themselves as consistent and thorough areas of subspecialization. (orig.)

Spiral CT pneumocolon: applications, status and limitations

International Nuclear Information System (INIS)

Harvey, C.J.; Renfrew, I.; Taylor, S.; Gillams, A.R.; Lees, W.R.

2001-01-01

CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit. (orig.)

Pathomorphism of spiral tibial fractures in computed tomography imaging.

Science.gov (United States)

Guzik, Grzegorz

2011-01-01

Spiral fractures of the tibia are virtually homogeneous with regard to their pathomorphism. The differences that are seen concern the level of fracture of the fibula, and, to a lesser extent, the level of fracture of the tibia, the length of fracture cleft, and limb shortening following the trauma. While conventional radiographs provide sufficient information about the pathomorphism of fractures, computed tomography can be useful in demonstrating the spatial arrangement of bone fragments and topography of soft tissues surrounding the fracture site. Multiple cross-sectional computed tomography views of spiral fractures of the tibia show the details of the alignment of bone chips at the fracture site, axis of the tibial fracture cleft, and topography of soft tissues that are not visible on standard radiographs. A model of a spiral tibial fracture reveals periosteal stretching with increasing spiral and longitudinal displacement. The cleft in tibial fractures has a spiral shape and its line is invariable. Every spiral fracture of both crural bones results in extensive damage to the periosteum and may damage bellies of the long flexor muscle of toes, flexor hallucis longus as well as the posterior tibial muscle. Computed tomography images of spiral fractures of the tibia show details of damage that are otherwise invisible on standard radiographs. Moreover, CT images provide useful information about the spatial location of the bone chips as well as possible threats to soft tissues that surround the fracture site. Every spiral fracture of the tibia is associated with disruption of the periosteum. 1. Computed tomography images of spiral fractures of the tibia show details of damage otherwise invisible on standard radiographs, 2. The sharp end of the distal tibial chip can damage the tibialis posterior muscle, long flexor muscles of the toes and the flexor hallucis longus, 3. Every spiral fracture of the tibia is associated with disruption of the periosteum.

Dose reduction in high-resolution MSCT. Examinations of the chest for early detection of pneumonia in immunocompromised patients; High-Resolution-MSCT-Thoraxuntersuchungen zur Infiltratsuche. Untersuchung einer Dosisreduktion bei immunsupprimierten Patienten

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Yamamura, J.; Adam, G.; Wedegaertner, U. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Wildberger, J.E.; Dichtl, D. [Klinik fuer Radiologische Diagnostik, RWTH Aachen (Germany); Nagel, H.D. [Philips Medizin Systeme GmbH, Hamburg (Germany)

2009-06-15

Purpose: the purpose of this study was to optimize high-resolution MSCT chest protocols for the evaluation of symptomatic immunosuppressed patients with suspected pneumonia using a dose-simulating program. Materials and methods: using the MSCT (Siemens, Erlangen, Germany), 30 immunosuppressed patients with suspected pneumonia were examined with a low-dose HRCT of the chest (120 kV, 100 eff.mAs and collimation of 4 x 1 mm). A dose-simulating program was used to reconstruct the raw data at four different dose levels (70, 50, 35 und 25 mAs). For dose simulation for each mAs product, the correspondent noise level was added to the data. Images were generated with a slice thickness of 1 mm and 5 mm in the lung window. The images were then evaluated independently by two radiologists and graded on a scale of 1 to 3 points: 1 = no pneumonia, 2 = unclear, 3 = pneumonia. A receiver operating curve (ROC) analysis was performed to calculate the area under the curve (AUC). The actual dosage in mSv was calculated. The sensitivity and specificity were evaluated. Results: out of 30 patients, 7 had a normal chest finding and 23 had pneumonia. The area under the ROC curve (AUC) was 1.0 for every dosage and slice thickness. Infiltrates were detected correctly for all dosage levels. The sensitivity was 100% for all dose levels and slice thicknesses. There was one false positive finding at 35 mAs and 1 mm slice thickness. At this dose level the specificity was reduced to 93%. A reduction to 25 mAs had no influence on the detection of pneumonia. Thus, MSCT examinations of the chest can be performed with 25 mAs without missing the right diagnosis, resulting in an effective dose of 1.15 mSv (men), 1.5 mSv (women) and a CTDIvol of 2.5 mGy. (orig.)

Influence of heart rate on diagnostic accuracy and image quality of 16-slice CT coronary angiography: comparison of multisegment and halfscan reconstruction approaches

International Nuclear Information System (INIS)

Dewey, Marc; Teige, Florian; Hamm, Bernd; Laule, Michael

2007-01-01

The lower the heart rate the better image quality in multislice computed tomography (MSCT) coronary angiography. We prospectively assessed the influence of heart rate on per-patient diagnostic accuracy and image quality of MSCT coronary angiography and compared adaptive multisegment and standard halfscan reconstruction. A consecutive cohort of 126 patients scheduled to undergo conventional coronary angiography was examined with 16-slice CT. For all heart rate groups, per-patient diagnostic accuracy was significantly higher for multisegment than halfscan reconstruction with values of 95 vs. 79% (p 74 bpm, 41 patients). Differences in diagnostic accuracy between adjacent heart rate groups were only significant for halfscan reconstruction for the comparison between the 65-74 and >74 bpm group (p < 0.05). The vessel lengths free of motion artifacts were significantly longer with multisegment reconstruction in all heart rate groups and for all coronary arteries (p < 0.005). For noninvasive MSCT coronary angiography, both per-patient diagnostic accuracy and image quality decline with increasing heart rate, and multisegment reconstruction at high heart rates yields similar results as standard halfscan reconstruction at low heart rates. (orig.)

Use of spiral computed tomography volumetry for determining the operative approach in patients with Graves' disease.

Science.gov (United States)

Choi, June Young; Lee, Kyu Eun; Koo, Do Hoon; Kim, Kyu Hyung; Kim, Eun young; Bae, Dong Sik; Jung, Sung Eun; Youn, Yeo-Kyu

2014-03-01

The purposes of the present study were to assess (1) the correlation between the weight of the postoperative thyroid specimen and the spiral computed tomography (CT) volumetry results of the thyroid gland in patients with Graves' disease, and (2) the utility of CT volumetry for determining the operative approach. From 2009 to 2010, a total of 56 patients with Graves' disease underwent total or subtotal thyroidectomy. An enhanced spiral CT was taken in all patients prior to the operation. From 2.5 mm-thick slices of the thyroid gland, the surface area was calculated to measure the volume of the thyroid gland. The glandular volume was compared to the weight of the postoperative thyroid specimen. A total of 42 and 14 patients underwent total and subtotal thyroidectomy, respectively. The mean weight of the postoperative thyroid specimen was 43.9 ± 33.4 g, and the mean volume obtained by CT volumetry was 44.2 ± 32.8 mL. A good correlation was observed between the weight of the postoperative thyroid specimen and the volume calculated by CT (r = 0.98, p 100 mL and the ≤100 mL groups (608.3 ± 540.8 vs. 119.7 ± 110.4 mL; p = 0.036). Spiral CT volumetry may be used to measure the thyroid volume reliably in patients with Graves' disease. For cases in which surgery is indicated in patients with Graves' disease, CT volumetry provides useful information from which to determine the operative approach. One hundred milliliter or less of thyroid volume in CT volumetry is recommended to perform minimally invasive thyroid surgery.

Value of preoperative enhanced multi-slice spiral CT scan for judging TNM staging of gastric cancer as well as its relationship with tumor marker and proliferation molecule expression

Directory of Open Access Journals (Sweden)

Ai-Jun Wu

2016-12-01

Full Text Available Objective: To study the value of preoperative enhanced multi-slice spiral CT scan for judging TNM staging of gastric cancer as well as its relationship with tumor marker and proliferation molecule expression. Methods: A total of 135 patients with gastric cancer who received surgical resection in our hospital between May 2012 and October 2015 were selected as the research subjects, preoperative enhanced multi-slice spiral CT scan was conducted to judge TNM staging, and serum was collected to determine the content of tumor markers; tumor tissue was collected after operation to determine the content of cytokines and pro-proliferation molecules. Results: CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM II, III and IV stage gastric cancer were significantly higher than those of patients with TNM I stage; CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM III and IV stage gastric cancer were significantly higher than those of patients with TNM II stage; CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM IV stage gastric cancer were significantly higher than those of patients with TNM III stage. Conclusions: TNM staging of gastric cancer decided by preoperative enhanced multi-slice spiral CT scan has good consistency with the content of tumor markers in serum and proliferation molecules in tumor lesion.

Abdominal and Pelvic CT

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Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

Computed Tomography (CT) -- Sinuses

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Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... the examination table will move during the scan, so that the x-ray beam follows a spiral ... and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections ...

Dose reduction in multi-slice CT of the heart by use of ECG-controlled tube current modulation (''ECG pulsing''): phantom measurements

International Nuclear Information System (INIS)

Poll, L.W.; Cohnen, M.; Brachten, S.; Moedder, U.; Ewen, K.

2002-01-01

To evaluate the effect of ECG-controlled tube current modulation on radiation exposure in retrospectively-ECG-gated multislice CT (MSCT) of the heart. Material and methods: Three different cardiac MSCT protocols with different slice collimation (4 x 1, and 4 x 2.5 mm), and a pitch-factor of 1.5 and 1.8 were investigated at a multi-slice CT scanner Somatom Volume Zoom, Siemens. An anthropomorphic Alderson-Rando phantom was equipped with LiF-Thermoluminescence dosimeters at several organ sites, and effective doses were calculated using ICRP-weighting factors. Scan protocols were performed with ECG-controlled tube current modulation ('ECG pulsing') at two different heart rates (60 and 80 bpm). These data were compared to previous data from MSCT of the heart without use of 'ECG pulsing'. Results: Radiation exposure with (60 bpm) and without tube current modulation using a 2.5 mm collimation was 1.8 mSv and 2.9 mSv for females, and 1.5 mSv and 2.4 mSv for males, respectively. For protocols using a 1 mm collimation with a pitch-factor of 1.5 (1.8), radiation exposure with and without tube current modulation was 5.6 (6.3) mSv and 9.5 (11.2) mSv for females, and 4.6 (5.2) mSv and 7.7 (9.2) mSv for males, respectively. At higher heart rates (80 bpm) radiation exposure is increased from 1.5-1.8 mSv to 1.8-2.1 mSv, using the 2.5 mm collimation, and from 4.6-5.6 mSv to 5.9-7.2 mSv, for protocols using 1 mm collimation. Conclusions: The ECG-controlled tube current modulation allows a dose reduction of 37% to 44% when retrospectively ECG-gated MSCT of the heart is performed. The tube current - as a function over time - and therefore the radiation exposure is dependent on the heart rate. (orig.) [de

Aortic non communicating dissections. A study with helical CT; Studio dell'ematoma intramurale aortico. Aspetti con Tomografia Computerizzata spirale

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Midiri, M.; Strada, A.; Stabile Ianora, A.A.; Rotondo, A.; Angelelli, G. [Bari Univ., Bari (Italy). Dipt. di Medicina Interna e Medicina Pubblica, Sez. di Diagnostica per Immagini; Scialpi, M. [Ospedale SS. Annunziata, Taranto (Italy); D' Agostino, D.; De Luca Tupputi Schinosa, L. [Bari Univ., Bari (Italy). Dipt. Emergenze Trapianto d' Organo, Sez. di Cardiochirurgia

2000-09-01

confused with aortic dissection. The imaging techniques (TEE, CT, MRI) have an important role in the final diagnosis of aortic hematoma. Presently Helical CT and MR angiography are the main tools in the early diagnosis of this condition before the development of complications. In this experience helical CT, before and after the administration of contrast material, was accurate in identifying the hematoma localization and extension. [Italian] Tale studio ha lo scopo di valutare con tecnica TC spirale gli aspetti semeiologici dell'ematoma intramurale dell'aorta e sottolineare il ruolo diagnostico decisivo di tale metodica nello studio di pazienti con quadro clinico acuto sospetto per dissezione aortica. E' stato condotto uno studio retrospettivo (dal 1995 al 1999) sulle immagini di 396 pazienti che avevano eseguito un esame TC in regime d'urgenza per sospetta dissezione aortica. Solo 18 pazienti (6 femmine, 12 maschi) presentavano aspetti tomodensitometrici caratteristici per ematoma intramurale aortico. Gli esami sono stati condotti tutti con TC spirale utilizzando i seguenti parametri: spessore dello strato 10 mm, image index 10, passo della spirale 1,5 mm, algoritmo standard con un minimo di 130 kV e 125 mA. Gli esami sono stati condotti prima e dopo iniezione di 130 ml di mdc in bolo rapido e ricercando i seguenti parametri: sede ed estensione longitudinale dell'ematoma spessore e densita' della parte aortica, presenza e localizzazione delle caclificazioni intimali, regolarita' del lume vero, presenza di emomediastino e/o emotorace. In tutti i 18 pazienti (8 di tipo A e 10 di tipo B) e' stato osservato ispessimento circoscritto parietale tipicamente iperdenso nelle scansioni di base e ipodenso in quelle dopo mdc. In 14/18 pazienti l'ispessimento assumeva disposizione eccentrica, in solo 4/18 era concentrico; in tutti i casi l'ispessimento e' risultato maggiore di 4 mm. In 18/18 pazienti sono state riscontrate

Diagnostic pathway of integrated SPECT/CT for coronary artery disease

International Nuclear Information System (INIS)

Slart, Riemer H.J.A.; Tio, Rene A.; Zijlstra, Felix; Dierckx, Rudi A.

2009-01-01