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[Objective] To investigate the clinical value of using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and dose technology.[Methods]A total of 60 patients (heart rate≤ 75 bpm and normal heart rhythm) with suspected aortic disease or post-operation were randomly divided into 2 groups:G1 (n =30;tube voltage:80 kV;contrast medium injection rate:3 mL/s;contrast medium dose:0.65 mL/kg)and G2 (n =30;tube voltage:120 kV;contrast medium injection rate:4 mL/s;contrast medium dose:1.2 mL/kg).The two groups underwent aorta angiography with prospective ECG-gating Helical protocol by using 320-detector CT.The mean CT values and standard deviation of aorta,coronaries and adjacent adipose tissue were measured,signal to noise ratio (signal-to-noise ratio,SNR)and contrast to noise ratio (contrast-to-noise ratio,CNR) were calculated.The subjective quality scoring of 3-d post-processing images were evaluated independently by 2 senior radiologists.The mean CT values and standard deviation of aorta,coronaries and adipose tissue,SNR,CNR,subjective quality scoring,contrast medium dose and radiation dose were compared and analyzed.[Results] The abnormal and normal rate of aorta in two groups were 83.33％ (25/30),16.67％ (5/30) and 86.67％ (26/30),13.33％(4/30);while the abnormal and normal rate of coronary arteries in two groups were 43.33％ (13/30),56.67％ (17/30) and 53.33％(16/30),46.67％ (14/30).SNR values of ascending aorta,descending aorta,abdominal aorta,superior mesenteric artery,bilateral renal artery,left main coronary artery,left anterior descending branch,left circumflex branch,right coronary artery and CNR values of abdominal aorta,superior mesenteric artery,bilateral renal artery,left anterior descending branch,left circumflex branch had no statistical significance,while the other indicators were significant differences between the two groups.The radiation dose and the contrast medium dose of G1 was significantly lower than G2 (P ＜ 0.05).There was no difference in the subjective image quality of 3D post-processing images between the two groups (P ＞ 0.05).[Conclusions] Using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and low contrast medium dose technology can help to reduce radiation and contrast medium dose without impacting on the imaging quality satisfactorily.
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[Objective] To evaluate the diagnostic values of multi-detector spiral computed tomography (MDCT) in pediatric sacrococcygeal tumors (SCT) and to improve the diagnostic ability.[Methods] 54 children (22 male and 32 female,age between 1 day and 16 years old) with pathologically confirmed SCT were involved in our study.All of them received 64-row spiral Computed Tomography before surgery,CT characteristics and clinical data were retrospectively analyzed.[Results] Pediatric SCT are more common in female children under four years old,with the germ cell tumors most common,followed by neurogenic tumors.Among the 54 SCT,39cases were malignant and 15 were benign (malignant∶ benign =2.60∶1).In CT image findings,37 cases (68％) were mainly solid mass,with 31 cases confirmed malignant by pathology.8 cases (15％) were mainly cystic,with all of them confirmed benign by pathology.9 cases (17％) were cystic-solid or with obvious necrosis in solid mass,with 8 cases confirmed malignant by pathology.[Conclusion] Malignant pediatric SCT are more common than benign SCT.Most malignant SCT are mainly solid mass or cystic-solid or with obvious necrosis in solid mass,and most benign tumors are mainly cystic.Combined with clinical data,MDCT can help to correctly diagnose SCT before surgery.
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Objective To study the feasibility of reducing radiation dose in aorto-iliac and lower extremity arteries CT angiography (CTA) with low tube voltage (100 kV) and automatic tube current modulation(ATCM).Methods Totally 61 patients requiting aorto-iliac and lower extremity arteries CTA for clinical reasons were prospectively enrolled in study.The patients were randomly assigned to 3 groups:Group A(120 kV),Group B (100 kV) and Group C (100 kV with automatic tube current modulation).Both quantitative and qualitative analysis were included in this research.Group C was divided into obese group(BMI≥ 24.9 kg/m2) and normal group(BMI ＜ 24.9 kg/m2).The radiation doses were analyzed respectively among two groups.Results The subjective evaluations of image quality for axial,MIP and VR were good.There were no significant differences among group A,B and C in SNR and CNR (P ＞0.05).The effective dose of group A,B and C was 8.20 mSv,5.36 mSv,and was 7.48 mSv,respectively Group B was 34.6％ less than group A.Group C was 39.5％ more than group B,and there was no significant differences between group A and C (P ＞ 0.05).The effective dose of group C1 was 7.11mSv,group C2 was 9.69 mSv,the E with group C1 were significantly less than group C2 (t =-3.163,P ＜0.05),the effective dose of group C1 was 13.3％ less than group A (Z =-2.822,P ＜ 0.05),but the group C2 was more than group A (P ＞ 0.05) and group B (Z =-3.426,P ＜ 0.05).Conclusions Lowkilovoltage (100 kV) CT scanning protocol is feasible in multi-detector CT angiography for aortoiliac and lower extremity arteries.Automatic low tube voltage (100 kV) with automatic tube current modulation (ATCM) scanning protocol can be used for someone with BMI less than 24.9 kg/m2.
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Objective To assess the feasibility of low-dose MDCT pulmonary angiography (MDCTPA) by using low kVp combined with individual-adapted low tube current protocol and noise reduction filter algorithms.Methods Fifty-six consecutively patients with MDCTPA were enrolled in the study.The patients were randomly divided into group A (120 kVp,100 mAs) and group B (100 kVp,individual-adapted tube current about 1.0 mAs/kg).Two series of images were reconstructed in group B:B1 with standard filter algorithms (FC13,B1) and B2 with noise reduction filter algorithms (FC11,B2).The image noise,quality and radiation dose in two groups were compared.Results The CTDIvol,DLP and E of group B were 5.1 mGy,83.3 mGy· cm and 1.4 mSv respectively,which were reduced by 64.3％,66.4％ and 66.7％,respectively (F =32.57,12.32,11.98,P ＜ 0.05) when compared with those in group A.Compared with group A,the image noise in B1 was increased by 118.2％ (t =10.05 P ＜0.05),the central and peripheral SNR and CNR and scores were increased by 51.5％,46.6％,50.8％,45.3％and 20.4％,respectively(t =7.20,6.30,6.58,5.54,8.35,P ＜ 0.05).Compared with B1,the image noise in B2 was reduced by 32.5％ (t =6.12,P ＜0.05),the central and peripheral SNR and CNR and scores were increased by 46.2％,46.2％,45.9％,46.9％ and 18.4％ (t =3.19,3.55,2.95,3.37,5.42,P ＜0.05).Compared with group A,the image noise in B2 group was increased by 47.3％ (t =4.03,P ＜0.05),the central and peripheral SNR and CNR and scores were reduced by 29.1％,21.8％,28.2％,19.6％ and 8.2％(t =4.06,2.82,3.68,2.22,3.02,P＜0.05).Conclusions Keeping effective diagnostic image quality,the protocol with low kVp and individual-adapted low tube current for low-dose MDCT pulmonary angiography would be effective and feasible,and the radiation dose would be significantly reduced.
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Objective To discuss the clinical application and significance of non-enhanced computed tomography axis rotating movie imaging technique in PCNL for complex renal calculi. Methods Thirty-one cases unilateral and 2 cases bilateral multiple and staghorn renal calculi with mild or mediurn hydronephrosis patients were performed bilateral kidneys non-enhanced CT scanning,three dimensional reconstruction and the axis rotating movie composition were carried on by computer software,PCNL accesses were designed and the residual stone were predicted referred to the access-calyces angle measured in axis rotating movie image,PCNL were performed after while.Comparing between preoperation accesses design and residual stone prediction with in-operation practice were carried out.Results The first PCNL access was constructed via posterior middle upper minor calyces in 22 renal units and via posterior middle lower minor calyces in 13 renal units,which was consistent with pre-operation design according to CT axis rotating movie image.The second PCNL accesses were constructed via lower calyx posterior upper minor calyces in 9 renal units and via lower calyx posterior lower minor calyces in 5 renal units,nephrolithotomy were performed in the same operation,clinical stone clearance rate was 80%(28/35),other 7 cases with residual stone were consistent with pre-operation prediction,No blood transfusion was necessary and no severe complication happened in all 33 cases.Conclusions Non-enhanced CT axis rotating movie imaging provided the detail three dimensional shape and spatial structure of complex renal calculi intuitively) that was benefit for designing appropriate PCNL accesses for complex renal calculi patients, guiding for searching stone fragments in operation, predicting residual stone, and ensuring operation safety.
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BACKGROUND: The middle ear is a little aerated cavity with a complex anatomy and a deep location. Computed tomagraphy virtual endoscopy (CTVE) can be used to reconstruct the stereoscopic images of internal surface of hollow organs using spiral CT volumetric data, providing findings similar to fiberendoscope.OBJECTIVE: To vedfy the ability to show the normal middle ear and the clinical application of virtual endoscopy based on 64-detector CT data.DESIGN, TIME AND SETTING: A confirmatory controlled observation was performed at Department of Radiology, First Affiliated Hospital of Sun Yat-sen University between October 2005 and March 2006.PARTICIPANTS: A total of 33 patients (66 ears) with suspected middle ear disease who underwent spiral CT examination were included in this study. Among included ears, 35 were normal, and 31 were impaired, including 24 ears presenting with chronic suppurative otitis media (10 simple otitis media, 5 granulomatous otitis media, and 9 middle ear cholesteatoma), 2 ears with post-operative recurred suppurative otitis media, 2 ears with carcinoma of middle ear, and 2 ears with temporal bone fracture, and lear with foreign body granuloma.METHODS: CT images of the temporal bone were obtained using 0.5 mm thick axis slices with a soft reconstruction kemel at 0.3 mm intervals. Virtual endoscopic images of middle ear on CT were generated from volumetric data using the Navigator software. CTVE images were observed from multiple directions using the Fly Through software, and compared with the axial and coronal images and surgery findings.MAIN OUTCOME MEASURES: The following structures were observed: auditory ossicle and joints, superior, middle, and inferior tympanum, sinus tympani, external acoustic meatus, tympanum, facial recess, tegmental wall, anterior and superior ligaments of malleus, posterior ligament of incus, and retrotympanum.RESULTS: A series of images were acquired as the virtual endoscope moved from the extemal auditory canal to the middle ear cavity. CTVE displayed the structures of normal middle ear with high details in 100%, except the anterior and posterior limbs of stapes in 68.6% (24/35) and 74.3 %(26/35), respectively. In the ears with supperative otitis media, the destruction of bone of handle, head of malleus, long and short limbs of incus, and limbs of stapes was found on CTVE in 91.7%(22/24), 95.8%(23/24), 95.8%(23124), 100%(24/24), and 87.5%(21/24), respectively. CTVE clearly showed the destruction of promontory, tegmental wall and facial nerve tube in one ear with carcinoma. CTVE showed the dislocation of incudomallear joint in one ear with temporal bone fracture. It took about 10-15 minutes to perform CTVE.CONCLUSION: CTVE can be used as a noninvasive and reliable method in displaying normal and pathologic middle ears. In cases of suspected bony destruction and confirmed trauma, it is helpful for diagnosis and surgical planning. CTVE of the middle ear can currently be considered as a complementary technique to conventional CT, and it is time-saving and reserves clinical generalization.
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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.
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The production, sell and price of drugs have had great variation in recent years. There is always a greater increase and decrease in drug market. In clinical therapeutic practice, the drugs required in smaller quantities are always out of stock, but the drugs required in larger quantities are usually in a state of supply over demand. An imbalance in supply and demand has been induced. The key for solution of the problem is to make market as guidance and production depend on need. The industrial and product structures should be urgently adjusted to make drug supply and demand toward benign circle. A general equilibrium in supply and demand is therefore attained.
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This paper analyses the present status of production and marketing as well as the existing problems about antipyretic analgesics at home and abroad. It presents the description on the recently developed products and new preparations. The trend of development in the future is anticipated as well.