ObjectiveTo investigate the influence of 70 kV low-dose CT perfusion technique on brain CT perfusion parameter maps and image quality. MethodsRetrospective analysis of all patients who underwent CT perfusion of brain between October 2013 and February 2014 was carried out. The patients were randomly divided into two groups according to diTherent CT examination dose: group A (80 kV, 200 mAs) and group B (70 kV, 200 mAs). All patients were scanned on a dual-source-CT (Siemens Definition Flash). Fifteen normal subjects without brain diseases in each group were selected to be studied. Region of interest (ROI) with an area of 80 mm2 was placed in the nucleus, putamen, thalamus, periventricular white matter of the frontal lobe and temporo-occipital area, and the parameters in the ROI including cerebral blood flow, cerebral blood volume, mean transit time and time to peak were detected. The carrierto-noise ratio and signal-to-noise ratio of thalamus and periventricular white matter of the frontal lobe were contrasted. The image quality of perfusion was assessed by two senior radiologists using 5 point system for blind assessment (5=best, 1=worst). The measurement of radiation dose was studied through effective dose, volume CT dose index (CTDIVOL) and dose length product (DLP). Statistical analysis was performed by independent sample t test. ResultsThere was no significant difference between group A and group B in brain CT perfusion parameters (P>0.05). There was no significant diTherence in image quality between the two groups in the objective and subjective assessment (P>0.05). In comparison with group A, the measured effective dose, CTDIVOL and DLP for group B decreased by 35%. ConclusionThere was no significant influence on the brain CT perfusion parameters and image quality using 70 kV tube voltage, and radiation dose is decreased obviously.
ObjectiveTo assess the values of MRI, ultrasound (US), and X-ray in the differential diagnosis of benign and malignant breast lesions. MethodsThe image data of 50 breast lesions confirmed with histopathology were analyzed retrospectively and the values of MRI, US and X-ray mammography in the differential diagnosis of benign and malignant breast lesions based on the breast imaging reporting and data system (BI-RADS) were assessed. The diagnostic efficiency of MRI, US, and X-ray in 50 benign and malignant breast lesions were compared using receiver operating characteristics (ROC) curves. The areas of ROC curves of MRI, US, and X-ray were calculated with Z test using SPSS 16.0. ResultsThere were 44 patients with 50 breast lesions, 26 malignant lesions, 24 benign lesions. Based on the BI-RADS, according to X-ray imaging features, 26 malignant breast lesions were classified as 5 lesions of category 5, 7 lesions of category 4, 6 lesions of category 3, 3 lesions of category 2, 1 lesion of category 1, 4 lesions of category zero. Twenty-four benign breast lesions were classified as 1 lesion of category 4, 3 lesions of category 3, 4 lesions of category 2, 13 lesions of category 1, 3 lesions of category zero. According to the characteristics of US findings, 26 malignant breast lesions were classified as 17 lesions of category 5, 4 lesions of category 4, 1 lesion of category 3, 1 lesion of category 2, 3 lesions of category 1. Twenty-four benign breast lesions were classified as 1 lesion of category 5, 2 lesions of category 4, 4 lesions of category 3, 14 lesions of category 2, 2 lesions of category 1, 1 lesion of category 0. According to MRI imaging findings, 26 malignant breast lesions were classified as 6 lesions of category 5, 18 lesions of category 4, 1 lesion of category 3, 1 lesion of category 1. Twenty-four benign breast lesions were classified as 20 lesions of category 1, 3 lesions of category 2, 1 lesion of category 3. The area under the ROC curve of the MRI, US, and X-ray was 0.977, 0.835, and 0.764, respectively. The differences of MRI with US (Z=2.05, P < 0.05) and MRI with X-ray mammography (Z=2.81, P < 0.05) were statistically significant. While the difference of US with X-ray mammography (Z=0.73, P > 0.05) was't statistically significant. ConclusionsDynamic contrast-enhanced MRI is an accurate examination in the differential diagnosis of benign and malignant breast lesions. The differential diagnostic efficiency of MRI is significantly better than those with US and X-ray.
ObjectiveTo evaluate the manifestations and diagnostic value of pediatric acute appendicitis with dual-source CT (DSCT). MethodsRetrospectively analysis of CT features of 97cases of surgically and pathologically confirmed pediatric acute appendicitis in our hospital were performed. ResultsAmong 97 patients, 7 cases were diagnosed acute simple appendicitis, 20 cases with acute suppurative appendicitis, perforated and gangrenous appendicitis in 58 cases, and appendiceal abscess in 12 cases. According to the location of appendix confirmed by CT, 28 cases of appendicitis could not be clearly manifested, the cohort of the remaining 69 cases were composed of 20 cases (29.0%) with appendix located in pelvic, 15 cases (21.7%) with appendix in front of ileum, 11 cases (15.9%) with appendix behind ileum, 12 cases (17.4%) with appendix behind cecum, 3 cases (4.3%) with appendix below cecum, 1 case (1.5%) with appendix outside of cecum, and 7 cases (10.2%) with appendix located in other positions. CT and three-dimensional reconstruction findings were as followed:swelling enlarged appendix, appendicoliths, periappendiceal fat fuzzy, peritoneal thickening, ileocecal thickening, mesenteric lymphadenopathy, periappendiceal mass, and abdominal or pelvic fluid. The diagnostic rate of acute simple appendicitis with CT was 85.7% (6/7), acute suppurative appendicitis was 80.0% (16/20), perforated and gangrenous appendicitis was 100% (58/58), appendiceal abscess was also 100% (12/12), the overall diagnostic yield was 94.8% (92/97). ConclusionDSCT can well demonstrate the anatomical location of appendix and pathological changes of surrounding tissues, and has higher diagnostic accuracy, provide powerful information for surgeons.
ObjectiveTo evaluate the CT findings and causes of thrombosis formation after transjugular intrahepatic portosystemic shunt (TIPS). MethodsOne hundred forty-two patients with cirrhosis after TIPS were included. The imaging features of thrombus in the stent after TIPS were recorded and causes of thrombosis formation were analyzed. The presence, location and amount of thrombus, the location of ends of TIPS stent were analyzed. ResultsThe incidence of thrombosis formation after TIPS was 19.0% (27/142). The thrombus could locate around the upper end (7.4%), lower end (18.6%) of the stent and inside the stent (74.0%), there was significant differences in the incidence of stent thrombosis in different locations (P < 0.05). The thrombus might presented as little mural thrombus (12/27, 44.4%), marked thrombus (3/27, 11.1%) and thrombotic occlusion (12/27, 44.4%), there was a significant difference in the incidence of stent thrombosis with different thrombus volume (P < 0.05). There were stent outlet vascular stenosis in most patients with stent thrombosis (88.9%). ConclusionsStent thrombosis after TIPS is common. Dual source computed tomography angiography could evaluate the thrombotic features. Stent outlet vascular stenosis might be associated with thrombosis formation after TIPS.
ObjectiveTo analyze the multidetector computed tomography (MDCT) findings of normal appendices and appendices of acute appendicitis in old patients, and to explore the clinical value of MDCT in assessing acute appendicitis in old patients. MethodsSixty-six cases of acute appendicitis confirmed by surgery in 24 hours after MDCT scan from Jun. to Oct. 2016 (acute appendicitis group), and 40 cases underwent MDCT scan for non-abdominal pain causes without appendiceal lesions from Sep. to Oct. 2016 (normal appendices group), were included, and the MDCT images of both 2 groups were retrospectively analyzed. Observation items included:location, diameter, mural thickness, intra-luminal contents, and changes of surrounding structures. Results① Rate of appendices visualization. In total of 95.5% (63/66) appendices were visualized on MDCT in acute appendicitis group, while 95.0% (38/40) appendices were visualized on MDCT in normal appendices group (P > 0.05). ② Locations of appendices. Acute appendicitis group:appendices were found to be located at pelvic cavity in 22 cases, in front of ileum in 2 cases, behind ileum in 10 cases, below cecum in 25 cases, and behind cecum in 4 cases. Normal appendices group:appendices were found to be located at pelvic cavity in 15 cases, in front of ileum in 3 cases, behind ileum in 7 cases, below cecum in 5 cases, and behind cecum in 8 cases. There was significant difference between 2 groups in terms of location of appendices (P < 0.05). The appendices in acute appendicitis group located mainly at pelvic cavity and below cecum, while the appendices in normal appendices group located mainly at pelvic cavity. ③ The diameter and thickness of appendices. The appendiceal diameter and thickness in acute appendicitis group were (11.4±4.2) mm (6.2-21.9) mm and (4.3±2.2) mm (1.1-8.6) mm, respectively, while those in normal appendices group were (6.1±1.4) mm (3.7-8.6) mm and (1.7±0.8) mm (0.5-3.2) mm, respectively. The diameter and thickness of appendices in acute appendicitis group were significantly greater than those in normal appendices group, respectively (P < 0.05). ④ Contents of appendices. Acute appendices group:there was effusion with air in 14 cases in appendiceal cavity, full of effusion in 36 cases, and appendicolith combined with effusion in 13 cases. Normal appendices group:there was full of air in 15 cases in appendiceal cavity, air with a little faeces of higher density in 13 cases, and nothing in 10 cases. Effusion was more common in appendiceal cavity in acute appendicitis group, while air was more common in normal appendices group. ⑤ Around appendices. Fat stranding was seen in 57 cases, adjacent parietal peritoneum thickening was seen in 56 cases, focal effusion was seen in 18 cases, abscess was seen in 2 cases, free air in peritoneal cavity was seen in 8 cases, and lymphadenopathy was seen in 35 cases. None of these imaging features were seen in normal appendices group. ConclusionsMDCT can demonstrate features of normal appendices and acute appendicitis in old patients. MDCT yield high diagnostic accuracy in acute appendicitis in old patients, and can provide useful information before surgery.