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Objective:To evaluate the short-term precision and accuracy of bone mineral density (BMD) measured with quantitative CT (QCT) and dual-energy X-ray absorptiometry (DXA) in multi-centre clinical research with a European spine phantom (ESP).Methods:From January 2016 to April 2020, totally 40 CT scanners (12 Siemens from Germany, 12 Philips from Netherlands, 9 GE from US, 5 Toshiba from Japan, 2 United Imaging from China) and 53 DXA instruments (34 GE Lunar from US, 14 Hologic from US, 5 Medlink from France) used in multi-centre in China were enrolled. The CT equipment came from 31 centers and DXA equipment from 32 centers.Using Mindways QCT software, the ESP was scanned 10 times on each instrument with repositioning using standardized spine protocols with QCT and DXA. The BMD value of the three lumbar vertebrae with low, medium, high density and the mean BMD value were measured. Accuracy was assessed by comparing BMD values measured on each device with the actual value of the phantom. Short-term precision was calculated as the root-mean-square standard deviation (RMS-SD) and root-mean-square standard deviation coefficient of variation (RMS-%CV) for the repeated measurements. The repeated measures variance analysis was used to compare the differences in BMD between different devices.Results:The differences in BMD values were statistically significant among different CT and DXA devices.The ranges of the accuracy measured by different QCT devices were 1.20% to 7.60% for Siemens, -1.83% to 0.20% for Philips, 1.18% to 13.20% for GE, -0.12% to 3.55% for Toshiba, -1.65% to 6.32% for United Imaging, 6.59% to 21.34% for GE Lunar, -6.65% to 5.45% for Hologic, and -6.97% to -0.68% for Medlink, respectively. The RMS-%CV of all vertebral BMD values measured by QCT and DXA ranged from 0.38% to 3.85%. The RMS-SD of QCT was 0.54 to 2.45 mg/cm 3, of DXA was 0.009 to 0.037 g/cm 2. The RMS-%CV values of each vertebral body measured by different QCT and DXA devices decreased with the increase of BMD, while the RMS-SD values showed the opposite tendency. Conclusions:Based on ESP, the QCT and DXA devices have significant differences in lumbar spine BMD measurement. Comparing the measurement results among different devices requires cross-calibration. Overall, the accuracy and short-term precision are within a reasonable range, which can be used for clinical follow-up observation. The short-term precision error and accuracy error range of QCT in evaluating the density of ESP were slightly smaller than those of DXA.
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Objective To evaluate the role of multi-disciplinary team (MDT) in improving the diagnosis and treatment of human herpes virus-6B (HHV-6B) encephalitis after liver transplantation. Methods MDT consultation was delivered for one rare case of HHV-6B encephalitis after liver transplantation to establish an effective individualized treatment regime. Results On the 16 d after liver transplantation, the patient developed headache, and suddenly presented with unresponsiveness, unconsciousness, coma complicated with involuntary limb twitching on the 18 d. Blood ammonia level was increased. Brain CT scan showed cerebral ischemic changes. Electroencephalography prompted the epileptic seizure. After MDT consultation, the possibility of nervous system infection after liver transplantation was considered, and medication therapy was given to control the epileptic seizure. Cerebrospinal fluid examination via lumbar puncture hinted increased intracranial pressure. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) of the cerebrospinal fluid demonstrated that the patient was tested positive for HHV-6B nucleic acid, which confirmed the diagnosis of HHV-6B encephalitis. The immunosuppressant regime was adjusted, intravenous ganciclovir was given for antiviral treatment, and active interventions were delivered to prevent and treat relevant complications. Epileptic seizure disappeared after 4 d, and neurological symptoms were significantly alleviated after 2 weeks. After 4-week antiviral treatment, the patient was tested negative for virology testing, and the neurological function was restored to normal. Conclusions HHV-6B encephalitis rarely occurs after adult liver transplantation, which is primarily associated with the virus reactivation after use of immunosuppressant. MDT pattern may be employed to deepen the understanding of the patient's condition, formulate more effective individualized treatment regime, and enhance the clinical efficacy and safety.
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Objective To assess the value of MSCT in the diagnosis of traumatic pancreatic injury.Methods The clinical and MSCT examination data of 38 patients with pancreatic injury admitted to our hospital were retrospective reviewed.Radiographic pancreatic injuries were classified as superficial or deep lesions,according to the depth of the injury to pancreas.Superficial lesions were defined as the hematomas or lacerations <50% of thickness of pancreas,deep lesions as the hematomas or lacerations >50% of thickness of pancreas.Results In 38 patients,32 patients underwent operative treatment,and other 6 patients underwent nonoperative treatment,including 20 patients with superficial injury and 18 patients with deep injury.The overall diagnostic coincidence rate of CT was 89.5%(34/38),and diagnostic coincidence rate for deep injury was 100%(18/18)with injury of the main pancreatic duct.Five cases of pancreatic injury were detected by CT enhancement and post-processing technique,and CT examination was considered negative in 4 cases of superficial injury.CT showed intrapancreatic or peripancreatic hematomas in 16 cases,pancreatic tear or laceration in 17 cases,pancreatic contusion in 10 cases, peripancreatic pseudocyst in 11 cases,dilation of the main pancreatic duct in 3 cases,traumatic pancreatitis in 20 cases and peripancreatic infection with abccess in 4 cases.Pancreatic injury presented as pancreatic or peripancreatic hematomas in early stage (within 7 days)and subsequently evolved into pancreatic tear or laceration and pseudocyst.Pancreatic injury was located in the pancreatic head in 10 cases,both in pancreatic head and neck in 1 case,in pancreatic neck in 10 cases,both in pancreatic neck and body in 1 case,in pancreatic body in 2 cases,both in pancreatic body and tail in 7 cases and in pancreatic tail in 7 cases.Pancreatic contusion was mainly located in pancreatic head (8/10, 80%).19 cases of simple pancreatic injury and 19 complex ones were showed in this study.Conclusion The diagnostic coincidence rate of CT for deep pancreatic injury is high with dilatation of the main pancreatic duct.CT findings of pancreatic injury are related to the time,site and degree of the pancreatic injury.CT enhancement and post-processing technique can improve diagnostic rate.
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Objective To evaluate the value of energy spectrum CT with multimodal quantitative parameters in diagnosis of the metastatic lymph nodes of gastric adenocarcinoma compared with the conventional CT.Methods 37 patients with gastric adenocarcinoma diagnosed by gastroscopy underwent enhanced CT scan with gemstone spectral imaging mode.We positioned and marked the stomach lymph nodes on CT images and compared with postoperative pathologic results one to one.ROC was used to identify the critical quantitative index of energy spectrum CT in distinguishing the metastasis from benign lymph node,and to evaluate the diagnostic effect compared with CT features.Results The 40-80 keV single energy spectrum curve slope (λHU )and normalized iodine concentration (NIC)in metastasis group were lower than those in the benign one in the arterial phase with statistical differences (P <0.05 ),but without statistical differences in venous phase.The combination of arterialλHU and NIC showed significant advantages compared with CT features(P <0.01), with the sensitivity,specificity and accuracy of 84.3% vs 61.4 %,88.4% vs 81.3 % and 86.8% vs 73.6 %.Conclusion The energy spectrum CT can provide quantitative analysis for differential diagnosis of gastric cancer metastasis from benign lymph nodes,and significantly improve the diagnostic accuracy of lymph node metastasis of the cancer.
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Objective To investigate the feasibility with low dose contrast agent in patients undergoing peripheral magnetic resonance angiography with high spatial resolution at open-bore 3 T scanner. Methods Images of MRA were assessed separately by two radiologists. And the images of DSA were assessed by one radiologist. The degree of the two interobservers' consensus for detection of arterial stenosis was determined by calculating the Kappa coef-ficient. Spearman rank correlation coefficient was used for revealing the relationship between contrast-enhanced MR angiography and DSA,in terms of categories of stenosis. Results For the degree of vessel stenosis, Cohen' s statis-tics revealed excellent agreement between the two observers. There was a significant correlation between DSA and MRA(P<0. 05). Conclusion At this open-bore 3 T scanner, high spatial resolution peripheral magnetic reso-nance angiography is achieved with low dose contrast agent.
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Purpose To explore the value of spectral CT imaging in differentiating pancreatic carcinoma and mass-forming pancreatitis, and to improve the preoperative diagnosis accuracy. Materials and Methods The dual-phase spectral CT imaging data in patients with pathology-proven pancreatic carcinoma (n=62) and mass-forming pancreatitis (n=30) were retrospectively analyzed. At 40-140 keV (with 10 keV increment), the mean CT values, energy spectrum curves and iodine concentrations were measured and compared between pancreatic carcinoma and mass-forming pancreatitis in arterial phase and portal venous phase. Results The mean CT values of mass-forming pancreatitis at 40-140 keV were higher than pancreatic carcinoma in both arterial phase and portal venous phase with significant difference (t= -7.349- -4.810, P<0.05; t= -6.760- -5.496, P<0.05). The energy spectrum curves were significantly different between pancreatic carcinoma and mass-forming focal pancreatitis, especially at 40-70 keV. The iodine concentrations of pancreatic carcinoma were lower than mass-forming pancreatitis in arterial phase and portal venous phase with significant difference (t=-28.577, P<0.05; t= -28.451, P<0.05). Conclusion Pancreatic carcinoma and mass-forming pancreatitis can be differentiated by measuring the CT value at different energies, energy spectrum curves and iodine concentrations.
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Objective To discuss the relationship between the diameter of portal vein and esophagogastric variceal bleeding and the severity of liver cirrhosis by CT portal venography ( CTPV). To analyze the occurence about esophagogastric variceal bleeding under in different liver cirrhosis degree. Methods 60 patients of portal hyperten-sion with liver cirrhosis and 15 healthy volunteers (controls). According to Child-Pugh classification, 60 patients were divided into Child-Pugh A,B and C groups,According to the patients whether the esophagogastric variceal bleeding or not, it was divided into two groups that esophagogastric variceal bleeding (EVB) and no EVB. All of patients underwent with 64-slice spiral CT. Image post-processing techniques such as MIP, VR, MPR and SSD were applied to measuring the diameters of portal venous system vessels and depict the portosystemic collaterals of portal venous system. Results The diameters of the right branch of portal vein and super mesenteric vein were no statisti-cal significance between bleeding group and no bleeding group. The rest parameters of portal system in EVB group are all larger than those of no EVB group(P<0.05). Age and gender in two groups had no statistic significance. All diameters of portal system in cirrhotic group were all larger than those of control group(P<0.05). In different liver function,there are differences in each groups of diameter. The bleeding rate of different groups according to he-patic function showed statistical significance(P <0.05), higher the degree of liver cirrhosis, higher the bleeding rate. Conclusion The diameters of portal system in EVB group are larger than no EVB. All diameters of portal sys-tem in cirrhotic group are all larger than those of control group. There is difference the diameter of vascular in differ-ent hepatic function. Different degree of liver cirrhosis can predict the esophagogastric variceal bleeding.
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Objective To analyze CT portal venography (CTPV) manifestations of portal collateral circulation in patients with cirrhosis by using a 16-detector row spiral CT scanner. Methods CTPV was performed in 36 patients with portal hypertension due to cirrhosis, the diagnosis was proved by clinical data, hepatic function findings and imaging signs. By using post-processing reconstruction technique, 3D images of portal venous system and portal collateral circulation were obtained. Results CTPV images displayed the portal venous system and its collateral circulation stereoscopically. Of 36 patients, left gastric varices were seen in 29 (80.6%), lower esophageal varices in 18 (50.0%), short gastric or posterior gastric varices in 15 (41.7%),paraesophageal varices in 9 (25.0%), gastro-renal or splenorenal shunts in 8 (22.2%), sponge-like transformation of portal vein in 7 (19.4%), paraumbilical and abdominal wall varices in 6 (16.7%), congenital cavernous in 6 (16. 7%) and paravertebral venous shunts in 4 (11.1%). Conclusion CTPV can well display the site, extent and severity of the portal collateral circulation in patients with portal hypertension due to cirrhosis, which is of great clinical importance for judging the patient's condition, for selecting therapeutic protocols and for estimating prognosis.
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Objective To study the multidetector CT (MDCT) features of soft tissue hemangiomas.Methods Plain CT,contrast-enhanced CT and CT angiographic findings of 20 patients with soft tissue hemangiomas confirmed by clinical,operative and pathologic data were retrospectively analysed.Results The lesions appeared as soft tissue density on CT and 5 cases with patchy calcification.There were various enhancement after administration of contrast media,net-like vessel enhancement intratumor both arterial and venous phase(12/20),the large supplying arteriae including simple feeding artery(4/12) and multiple feeding arteriae(8/12) could be seen,and varix within the tumors(6/12),no or mild enhancement in other cases(8 cases) on arterial phase,and homogeneous enhancement on venous phase also presented.Conclusion The imaging findings such as shape,size,supplying artery of soft tissue hemangiomas can be showed clearly by MDCT angiography.