Arterial Spin Labeling Magnetic Resonance Imaging in Healthy Adults: Mathematical Model Fitting to Assess Age-Related Perfusion Pattern

Objective@#To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. @*Materials and Methods@#In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey’s regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. @*Results@#Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. @*Conclusion@#In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.

Arterial Spin Labeling Magnetic Resonance Imaging in Healthy Adults: Mathematical Model Fitting to Assess Age-Related Perfusion Pattern

Objective@#To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. @*Materials and Methods@#In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey’s regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. @*Results@#Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. @*Conclusion@#In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.

Investigation of aquaporin-1 expression and diffusion weighted imaging with multiple b values in adrenal gland in a rat model of diabetes mellitus / 中华放射学杂志

Objective To investigate the character of aquaporin-1(AQP-1)expression in adrenal gland in diabetes mellitus and evaluate adrenal gland damage and function alterations by DWI with multiple b values. Methods Twenty male Sprague-Dawley rats were randomly selected by computer and randomized into 2 groups:untreated controls(n=10)and diabetes(DM)(n=10). Rats in diabetes group were fed with high-sucrose and high-fat diet, controls were fed with common diet. After fed with high-sucrose and high-fat diet for 4 weeks, rats in diabetes group were injected with streptozotocin(STZ). Forty days after diabetes induction with streptozotocin(STZ), MR imaging was performed in a 7.0 T scanner. Venous blood from the tails was collected before MRI scan to measure blood glucose, blood glucose more than 16.7 mmol/L wasregarded as diabetic status. All the rats underwent DWI with 18 b values(0 to 4500 s/mm2). Maps of pure diffusion coefficients(D), pseudo-diffusion coefficients(D*)and ultra-high ADC(ADCuh)were acquired. Rats were sacrificed after MRI scan for adrenal gland histopathology, AQP-1 immunohistochemistry analysis and AQP-1 optical density(OD)measurements. Student t test was used to compare the difference of D*, D, ADCuh and OD of AQP-1 between two groups. Results Eight diabetic animals developed hyperglycemia(two rats died during the modeling process). MRI scan was performed in all of the 18 rats. Signal intensity of D*map, D map and ADCuh map decreased gradually. ADCuh increased significantly in DM animals(0.24 ± 0.06) × 10-3mm2/s compared with control animals(0.18 ± 0.07) × 10-3 mm2/s(P0.05). There was a noticeable increase in the AQP-1 labeling in the adrenal cell membrane and cytoplasm in DM animals compared with control animals. DM rats showed an increased OD value of AQP-1 in adrenal gland compared with the control animals(P<0.05). Conclusions We found significantly higher AQP-1 expression in adrenal gland in DM animals compared with controls. Ultra-high b-Values DWI may work as a useful way for noninvasive evaluation the change of adrenal function in DM.

Progresses of MRI in diagnosis of chronic pancreatitis / 中国医学影像技术

Chronic pancreatitis is a chronic inflammatory disease of the pancreas,whichcan lead to irreversible damage to the morphology and function of the pancreas ultimately.So the early diagnosis and treatment for chronic pancreatitis are very important.And the differentiation between mass-forming chronic pancreatitis and pancreatic cancer is also a difficult problem in clinic.MRI as a noninvasive and nonradiative examination with excellent soft tissue resolution,is very valuable for the diagnosis of chronic pancreatitis.And the combination of functional MRI and conventional MRI is very helpful for the differentiation between pancreatic carcinoma and mass-forming chronic pancreatitis,which is of great significance to the clinical management.The application and progresses of function MRI in the diagnosis and identification of chronic pancrea titis were reviewed in this article.

The feasibility of dual-source CT virtual scan replace conventional scan in the peritoneography / 中华放射学杂志

Objective To explore the feasibility of dual-source CT virtual scan replace conventional scan in the CT peritoneography. Methods Prospective enrolled 29 cases who accepted peritoneal dialysis (PD) treatment and were highly suspected with PD-related complications. The patients were firstly underwent CT conventional in the fasting state by applied the dual-source CT (single energy pattern), and then 2 L dialysate which mixed with contrast medium was infused into peritoneal cavity, and the CT scan was performed again after 30 min (dual-energy pattern). Scaning data were processed by virtual post-processing software to obtain virtual CT scan imaging. Subjective evaluation (including lesions and image quality score) and objective evaluation (including the CT value, noise and signal to noise ratio) were performed on the conventional scan and virtual scan, and recorded the radiation dose. Wilcoxon test was used to analyse the differences of lesions revealing and image quality score of conventional scan imaging and virtual scan imaging, and paired t test was applied to compare the differences of radiation dose and the other quality objective evaluation index. Results There was no significant difference between conventional CT scan and virtual CT scan in the cyst, calcification, calculus, hematoma and catheterization (P>0.05). The image quality score of conventional CT scan and virtual CT scan was 5.0±0.0 and 4.9±0.4, and there was no significant difference (Z=-1.6,P=0.10). There was no statistically significant difference in CT value of muscle, kidney, subcutaneous fat, urine in bladder and intraperitoneal fluid between the two groups (P>0.05), and the CT value of liver in the virtual CT scan was higher than that in the conventional CT scan (P<0.05), but the value of bone in the virtual CT scan was lower than that in the conventional CT (P<0.05). The noise of conventional CT was significant higher than that of invirtual CT, but the SNR was significant lower than virtual CT scan (P<0.05). The effective radiation dose in the conventional CT scan and virtual CT scan were(9.6±1.4)and(15.9±4.9)mSv, and showed significant difference. Furthermore, the effective radiation dose decreased by 39.6%(6.3/15.9). Conclusion Dual-energy CT scan can replace conventional CT scan in the CT peritoneography, which can guarantee the accuracy of diagnosis and reduce radiation dose.

Value of low-dose furosemide for normal upper urinary during CT urography / 实用放射学杂志

Objective To explore the value of intravenous low dose furosemide on visualization of upper urinary tract during CTU. Methods 39 cases of normal upper urinary samples were examined by CTU with 5 minutes delayed,19 cases underwent intravenous injection of furosemide.The upper urinary tract was divided into 5 parts for scoring of images on a 5 score scales for opacification,the average value of ureter short axis of distention,and CT value by contrast material were measured.Results were analyzed by t test using SPSS.Results (1)30/38 segments of upper urinary tract were all or almost all opacification in furosemide group,the scores of upper urinary tract were higher than that of the control group,which had significant difference except the pelvis and left proximal ureter segments. (2)The disention of the ureter was significantly higher for all segments in furosemide group.(3)CT values in furosemide group decreased significantly for all upper urinary tract.Conclusion CTU excretory phase image acquisition with intravenous low dose furosemide is helpful on visualization of upper urinary tract.

Early abnormalities of kidneys in patients with primary hypertension by 3.0 T functional magnetic resonance imaging / 生物医学工程学杂志

This study aims to detect early changes of kidney in patients with primary hypertension by 3.0 T functional magnetic resonance imaging (fMRI). 26 patients with primary hypertension (hypertension group) and 33 healthy volunteers (control group) underwent conventional and functional magnetic resonance scans, which included blood oxygen level-dependent (BOLD) MRI, diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI). We measured renal cortical thickness (CT), parenchymal thickness (PT), and functional values of renal cortex and medulla including R2* value, apparent diffusion coefficient (ADC) value and fractional anisotropy (FA) value in each group, and then calculated the cortical/parenchymal thickness ratio (CPR). Compared with those in the control group, CT and CPR in hypertension group were larger (P < 0.01), cortical and medullar R2* values increased (P < 0.01) whereas medullar FA values decreased (P < 0.05). It could be well concluded that noninvasive 3.0 T functional MRI would have important clinical significance in identifying early abnormalities of kidney in hypertension patients.

Intrapancreatic pseudocysts after acute pancreatitis / 中华肝胆外科杂志

Objectives The study aims were to analyze the clinical features and to explore the management of intrapancreatic pseudocysts after acute pancreatitis.Methods A retrospective study was conducted on 151 patients who received surgical treatment from Dec,2008 to Feb,2012 after acute pancreatitis.Based on CT/MRI findings and clinical data,there were 17 patients with intrapancreatic pseudocysts (11.3％).The clinical manifestations,diagnoses and treatments for these 17 patients were retrospectively analyzed,and the outcome after operations were followed.Results For the 17 patients,obstructive jaundice was present in 3 patients,pancreatic portal hypertension (PPH) in 7,pseudoaneurysm in 2.All 17 patients underwent operation.The surgical procedures included internal drainage (n=8),external drainage (n=5),distal pancreatic resection with splenectomy (n=3),and local resection (n=1).All patients recovered after the operations.Conclusions Intrapancreatic pseudocysts after acute pancreatitis had a high incidence of local complication.The diagnosis of these pseudocysts was difficult.The treatment should be performed early for those patients who had developed complications.

Application of magnetic resonance imaging in differential diagnosis for tuberculous pyonephrosis and hydronephrosis / 中华全科医师杂志

Objective To probe the value of varied magnetic resonance imaging(MRI) techniques applied in differential diagnosis of tuberculous pyonephrosis from hydronephrosis.Methods Features of MRI,including in T_1WI with/without enhancement,T_2WI,urology MRI and diffusion weighted image(DWI),in seven cases with tuberculous pyonephrosis and 10 cases with hydronephrosis pathologically confirmed were retrospectively analyzed.Results Regular T_1WI and T_2WI could show morphology of the whole kidney,destruction of renal parenchyma and empyema.T_1WI with enhancement could manifest abnormally reinforced walls of pyoid cavity,renal pelvis and calyx and ureter.Urology MRI could show morphology of the whole urinary passage with pathological changes more clearly.Accuracy of these techniques was 84.7%.DWI had the advantage of analyzing diffusion image and ADC map to understand diffusion features of water molecule,and of quantitating ADC value to differentiate tuberculous pyonephrosis from hydronephrosis,with an accuracy of 91.2% combining with DWI and other methods.Conclusion Combined application of varied MRI techniques should be highlighted in differentiation of tuberculous pyonephrosis and hydronephrosis with a higher accuracy of diagnosis.

CT Radiological Anatomy of Adult Groin Region / 中国普外基础与临床杂志

Objective To investigate the application of multi-detector row spiral CT(MDCT)and multi-planer reconstruction(MPR)in identify the anatomy detail of normal adult groin region.Methods We retrospectively collected the CT images of 50 adult subjects with normal groin anatomic structure underwent groin region thin-slice MDCT scans between July and December 2009,30 males and 20 females,obtained the coronal and sagittal views by MPR,investigated the value of different plans in identifying anatomic detail.Results Bilateral inferior epigastric artery(100/100,100%),spermatic cord(60/60,100%),and round ligament of uterus(40/40,100%)were well identified on all plans in all subjects.The bilateral "radiological femoral triangle" could be demonstrated on coronal views in all subjects(100/100,100%).The bilateral inguinal ligament were visible on coronal view in all subjects(100/100,100%)and on sagittal views in 34 subjects(68/100,68%),but on axial views was identified in 3 male subjects(6/100,6%).The bilateral inguinal canal and deep inguinal ring were reliably visible on coronal views in all subjects(100/100,100%),and on sagittal views in 46 subjects(92/100,92%).On coronal views,the widths of inguinal canal was(0.97?0.35)cm in left,(0.89?0.23)cm in right for males,and(0.62?0.11)cm in left,(0.71?0.11)cm in right for females.No significant difference was found between two sides(P=0.059 in males,P=0.067 in females),but there were significant differences between males and females(P=0.007 in left,P=0.009 in right).Transverse diameter of deep inguinal ring was(1.32?0.31)cm in left,(1.31?0.36)cm in right for males,and(1.07?0.35)cm in left,(1.07?0.30)cm in right for females.No significant difference was found between two sides(P=0.344 in males,P=0.638 in females),but there were significant differences between males and females(P=0.001 in left,P=0.002 in right).Conclusion MDCT with different plans plays an important role in identify the anatomic details of groin region,the coronal views especially.

Review of Magnetic Resonance Diffusion-Weighted Imaging in Liver / 中国普外基础与临床杂志

Objective To review the examination techniques and the current research progress of the magnetic resonance diffusion weighted-imaging (DWI) used in liver. Methods The recent and relevant literatures about the principles and the current study situation of liver DWI were scrutinized and analyzed retrospectively. In addition, the existing problems of liver DWI were discussed. Results DWI could demonstrate the normal and abnormal structure and function through measuring the diffusion motions of water molecule in the liver. With the improving technology and better understanding of diffusion dynamics, DWI has been used for the diagnosis and differential diagnosis for hepatic diseases. Conclusion DWI as a non-invasive examine method, may provide valuable functional information for clinical diagnosis and treatment.

Assessment of Bile Duct Complications after Cholecystectomy with Magnetic Resonance Imaging / 中国普外基础与临床杂志

Objective To investigate the value of magnetic resonance (MR) imaging in the assessment of bile duct complications after cholecystectomy. Methods Fifty patients of having bile duct complications after cholecystectomy underwent MR imaging and had some positive manifestations. The indication for cholecystectomy was symptometic cholelithiasis in all cases. MR imaging was performed with a 1.5 T clinical imager including all of the sequences of: ①T1 weighted imaging (T1WI) was performed in transverse and coronal plane before and after gadolinium enhanced. ②T2 weighted imaging (T2WI) was performed in transverse plane. ③A true fast imaging with steady state precession sequence (True fisp) was performed in coronal plane. ④MR cholangiopancreatography was also obtained. Results The bile duct complications after cholecystectomy including: 22 cases of cholelithiasis, 15 cases of chronic cholangitis with or without bile duct abscess. Bile duct strictures or abruption at the confluence of hepatic and common bile duct in 6 and 3 cases respectively. Tumors of bile duct or pancreas in 9 cases. The other complications after cholecystectomy including bile leak with choleperitonitis and/or biloma and acute pancreatitis.Conclusion MR imaging was a valuable method for the assessment of bile duct complications after cholecystectomy. MR imaging could assess the etiology of bile duct complications. If there were bile duct obstruction, MR imaging could assess the location and the severe of obstruction. For bile duct or pancreatic tumors, MR imaging could assess the areas of tumor infiltration and resection and was helpful to select treatment methods. Before lapatoscopic cholecystectomy, the overall and careful imaging assessment for bile duct and gallbladder and its adjacent hepatic tissue and pancreas so to avoid missing the relative tumors.

An initial analysis on the status quo of applying diagnosis test in imaging scientific study in China / 中华放射学杂志

Objective To analyze the status quo of applying diagnosis test in imaging scientific study in China, and to see whether reliable diagnosis can be provided to clinicians for accurate guidance of clinical management. Method We manually looked up diagnosis tests published in 1979～1999 "Chinese Journal of Radiology" that is quite influential in our country. Then we evaluated each of these diagnosis tests according to the International Standards. Results We totally searched 2 888 articles in which only 9% were diagnosis tests. Of these diagnosis tests, only 8.9% applied blind comparison with Gold Standard, 24% calculated sensitivity, specificity and accuracy in the same time. And only 0.5%?6% and 5.7% respectively calculated likelihood ratios, negative predictive value and positive predictive value. Conclusion In China, the quality and quantity of the diagnosis tests applied in the specialty of imaging scientific study is far from meeting the clinical demand. Improving methods of scientific study and carrying on more diagnosis tests of high quality are of important significance to improving the diagnostic level of imaging.

Diffusion-weighted MR imaging in functional study of kidney / 中华放射学杂志

Objective To evaluate the value of diffusion-weighted MRI in the functional study of kidney.Methods Fifteen volunteers as control group and 32 patients with chronic kidney disease(CKD) were underwent DW MR imaging in a dehydrated state.In CKD group,12 cases were with normal serum creatinine(Scr) level(CKD group 1) and 20 cases with Scr increased in different level(CKD group 2).Apparent Diffusion Coefficient(ADC) value of each kidney of all groups was measured and compared of their relationships with clinical data.Results The ADC values of 15 volunteers in different b values(50,100,400) were(405.366?35.9639)?10~(-5)mm~2/s,(339.646?23.0594)?10~(-5)mm~2/s,and(254.532?13.6763)?10~(-5)mm~2/s,respectively.The ADC values of CKD group 1 were(336.622?12.879)?10~(5)mm~2/s,(308.142?20.998)?10~(-5)mm~2/s,and(211.398?14.604)?10~(-5)mm~2/s,respectively.And of CKD group 2 were(307.717?84.930)?10~(-5)mm~2/s,(265.415?57.754)?10~(-5)mm~2/s,and(201.672?26.411)?10~(-5)mm~2/s,respectively.The ADC values in CKD group were lower than those of the normal kidneys(t values compared between the control group and CKD group 1 were 9.720,5.190,11.093 separately,between the control group and CKD goup 2 were 6.533,7.382,10.864 separately in different b values,with all P values less than 0.05).In CKD group 2,it had been showed negtive correlation between the level of Scr and ADC values of kidney,with mean level of Scr of(828.490?699.350) ?mol/L,but this was confirmed of no statistical meanings(the coefficient correlation were(-0.272、)-0.283、-0.023 separately in different b values,with p values more than 0.05).For the creatinine clearance rate(Ccr),it showed a weak positive correlation with ADC values of CKD group 2(the coefficient correlation were 0.511、0.430、0.335 separately,with P values less than 0.05).Conclusion(Diffusion-weighted) MRI imaging and in vivo measurement of ADC values have the potential for use as a noninvasive means to explore the functional status of the kidney.

The spiral CT manifestations of the blood supply of primary hepatocellular carcinoma: correlation with pathologic findings / 中华放射学杂志

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, pseudoglandular, 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

Correlative study of left subphrenic fat infiltration with clinical-imageological staging in acute pancreatitis / 中华放射学杂志

Objective To study the correlation between the manifestations of the left subphrenic fat infiltration (LSFI) and the severity of acute pancreatitis (AP) Methods One hundred and forty four cases and 188 cases of AP scored by Ranson′s scoring system and graded by Balthazar′s staging system were retrospectively studied respectively The thickness of the LSFI in each case was respectively and individually observed and measured, and the thickness under 3 mm was graded as 0 of which the sign of LSFI was considered as negative Rank correlation analysis of the thickness of LSFI with Ranson′s scoring and Balthazar′s staging was used respectively Results The incidence of LSFI in Ranson′s rank 1-3 was 30 86%, 54 90%, and 75 00%, respectively, and rank correlation coefficient of LSFI and Ranson′s score was 0 417 9( P