A nomogram for prediction of ERCP success in patients with bile duct leaks: a multicenter study.

BACKGROUND: Bile duct leaks (BDLs) are serious complications that occurs after hepatobiliary surgery and trauma, leading to rapid clinical deterioration. Endoscopic retrograde cholangiopancreatography (ERCP) is the first-line treatment for BDLs, but it is not clear which patients will respond to this therapy and which patients will require additional surgical intervention. The aim of our study was to explore the predictors of successful ERCP for BDLs. METHODS: A retrospective analysis was conducted using data from six centers' databases. All consecutive patients who were clinically confirmed as BDLs were included in the study. Collected data were demographics, disease severity, and ERCP procedure characteristics. Univariate and multivariate analysis were used to select independent predictive factors that affect the outcome of ERCP for BDLs, and a nomogram was established. Calibration and ROC curves were used to evaluate the models. RESULTS: Four hundred and forty-eight consecutive patients were clinically confirmed as BDLs and 347 were excluded. In the 101 patients included patients, clinical success was achieved in 78 patients (77.2%). In logistic multivariable regression, two independent factors were negatively associated with the success of ERCP: SIRS (OR, 0.183; 95% CI 0.039-0.864; P = 0.032) and high-grade leak (OR 0.073; 95% CI 0.010-0.539; P = 0.010). Two independent factors were positively associated with the success of ERCP: leak-bridging drainage (OR 4.792; 95% CI 1.08-21.21; P = 0.039) and cystic duct leak (OR 6.193; 95% CI 1.03-37.17; P = 0.046). The prediction model with these four factors was evaluated using a receiver-operating characteristic (ROC) curve, which demonstrated an area under the curve of 0.9351. The calibration curve showed that the model had good predictive accuracy. CONCLUSION: Leak-bridging drainage and cystic duct leak are positive predictors for the success of ERCP, while SIRS and high-grade leak are negative predictors. This prediction model with nomogram has good predictive ability and practical clinical value, and may be helpful in clinical decision-making and prognostication.

Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma: Comparison with conventional diffusion-weighted imaging.

AIM: To compare intravoxel incoherent motion (IVIM)-derived parameters with conventional diffusion-weighted imaging (DWI) parameters in predicting the histological grade of hepatocellular carcinoma (HCC) and to evaluate the correlation between the parameters and the histological grades. METHODS: A retrospective study was performed. Sixty-two patients with surgically confirmed HCCs underwent diffusion-weighted magnetic resonance imaging with twelve b values (10-1200 s/mm2). The apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated by two radiologists. The IVIM and conventional DWI parameters were compared among the different grades by using analysis of variance (ANOVA) and the Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing between low-grade (grade 1, G1) and high-grade (grades 2 and 3, G2 and G3) HCC. The correlation between the parameters and the histological grades was assessed by using the Spearman correlation test. Bland-Altman analysis was used to evaluate the reproducibility of the two radiologists' measurements. RESULTS: The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCCs were statistically significant (P < 0.001). The D* and f values had no significant differences among the different histological grades of HCC (P > 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating the low-grade HCC from the high-grade HCC, with areas under the curve (AUCs) of 0.909 and 0.843, respectively, measured by radiologist 1 and of 0.911 and 0.852, respectively, measured by radiologist 2. The following significant correlations were obtained between the ADC, D, and D* values and the histological grades: r = -0.619 (P < 0.001), r = -0.628 (P < 0.001), and r = -0.299 (P = 0.018), respectively, as measured by radiologist 1; r = -0.622 (P < 0.001), r = -0.633 (P < 0.001), and r = -0.303 (P = 0.017), respectively, as measured by radiologist 2. The intra-class correlation coefficient (ICC) values between the two observers were 0.996 for ADC, 0.997 for D, 0.996 for D*, and 0.992 for f values, which indicated excellent inter-observer agreement in the measurements between the two observers. CONCLUSION: The IVIM-derived D and ADC values show better diagnostic performance in differentiating high-grade HCC from low-grade HCC, and there is a moderate to good correlation between the ADC and D values and the histological grades.

Preliminary study of brain glucose metabolism changes in patients with lung cancer of different histological types.

BACKGROUND: Cerebral glucose metabolism changes are always observed in patients suffering from malignant tumors. This preliminary study aimed to investigate the brain glucose metabolism changes in patients with lung cancer of different histological types. METHODS: One hundred and twenty patients with primary untreated lung cancer, who visited People's Hospital of Zhengzhou University from February 2012 to July 2013, were divided into three groups based on histological types confirmed by biopsy or surgical pathology, which included adenocarcinoma (52 cases), squamous cell carcinoma (43 cases), and small-cell carcinoma (25 cases). The whole body 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) of these cases was retrospectively studied. The brain PET data of three groups were analyzed individually using statistical parametric maps (SPM) software, with 50 age-matched and gender-matched healthy controls for comparison. RESULTS: The brain resting glucose metabolism in all three lung cancer groups showed regional cerebral metabolic reduction. The hypo-metabolic cerebral regions were mainly distributed at the left superior and middle frontal, bilateral superior and middle temporal and inferior and middle temporal gyrus. Besides, the hypo-metabolic regions were also found in the right inferior parietal lobule and hippocampus in the small-cell carcinoma group. The area of the total hypo-metabolic cerebral regions in the small-cell carcinoma group (total voxel value 3255) was larger than those in the adenocarcinoma group (total voxel value 1217) and squamous cell carcinoma group (total voxel value 1292). CONCLUSIONS: The brain resting glucose metabolism in patients with lung cancer shows regional cerebral metabolic reduction and the brain hypo-metabolic changes are related to the histological types of lung cancer.

Crossed cerebellar diaschisis detected by arterial spin-labeled perfusion magnetic resonance imaging in subacute ischemic stroke.

BACKGROUND: Crossed cerebellar diaschisis (CCD) was a common radiological phenomenon manifested as reduced blood flow and metabolism in the cerebellar hemisphere contralateral to a supratentorial cerebral lesion. The hypoperfusion and hypometabolism in the contralateral cerebellum in CCD was traditionally detected by positron emission tomography (PET) and single-photon emission computed tomography (SPECT). The present prospective study aimed to assess the detection of CCD in subacute stage ischemic stroke by arterial spin-labeling (ASL) perfusion technique with a 3.0-T magnetic resonance imaging (MRI) scanner. METHODS: ASL images were obtained from 46 patients with supratentorial ischemic stroke at subacute stage. Regional cerebral blood flow values in the cerebellar hemispheres were measured on a region of interest basis. RESULTS: Twenty-four of 46 (52%) patients showed CCD phenomenon by ASL-MRI method, which was in line with the PET/SPECT series. Infarctions in basal ganglia areas are prone to cause CCD. CONCLUSIONS: With advantages in easy acquisition and no radiation, ASL-MRI seems to be an ideal tool for the detection and follow-up of CCD.

Initial study of magnetic resonance diffusion tensor imaging in brain white matter of early AIDS patients.

BACKGROUND: HIV is a neurotropic virus which can cause brain white matter demyelination, gliosis, and other pathological changes that appear as HIV encephalitis or AIDS dementia. The purpose of this study was to investigate the change of the diffused condition of water molecules in brain white matter in early acquired immune deficiency syndrome (AIDS) patients using MR diffusion tensor imaging (DTI). METHODS: DTI examinations were performed on a Siemens 3.0T MR scanner in 23 AIDS patients with normal brain appearance by conventional MRI and 20 healthy volunteers as the control group. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured in nine regions; corpus callosum (CC) knee, CC body, CC splenium, periventricular white matter, frontal lobe white matter, parietal lobe white matter, occipital lobe white matter, and the anterior and posterior limbs of the internal capsule. The mean FA and ADC values from each region were compared in three groups: the symptomatic, asymptomatic and the control. RESULTS: The mean FA values were significantly lower and the mean ADC values were significantly higher in all nine regions in patients in the symptomatic group than in the asymptomatic and control group patients. In the asymptomatic group, the mean FA values were significantly lower and the mean ADC values were significantly higher at the CC knee, CC body, CC splenium, periventricular white matter, frontal lobe white matter and parietal lobe white matter, than in the control group. There were no significant differences at other regions between the two groups. CONCLUSIONS: The diffused changes of water molecules in brain white matter in AIDS patients are related to brain white matter regions. DTI examination can detect the brain white matter lesions early in AIDS patients.

Susceptibility weighted imaging: a new tool in the diagnosis of prostate cancer and detection of prostatic calcification.

BACKGROUND: Susceptibility weighted imaging (SWI) is a new MRI technique which has been proved very useful in the diagnosis of brain diseases, but few study was performed on its value in prostatic diseases. The aim of the present study was to investigate the value of SWI in distinguishing prostate cancer from benign prostatic hyperplasia and detecting prostatic calcification. METHODOLOGY/PRINCIPAL FINDINGS: 23 patients with prostate cancer and 53 patients with benign prostatic hyperplasia proved by prostate biopsy were scanned on a 3.0T MR and a 16-row CT scanner. High-resolution SWI, conventional MRI and CT were performed on all patients. The MRI and CT findings, especially SWI, were analyzed and compared. The analyses revealed that 19 out of 23 patients with prostate cancer presented hemorrhage within tumor area on SWI. However, in 53 patients with benign prostatic hyperplasia, hemorrhage was detected only in 1 patient in prostate by SWI. When comparing SWI, conventional MRI and CT in detecting prostate cancer hemorrhage, out of the 19 patients with prostate cancer who had prostatic hemorrhage detected by SWI, the prostatic hemorrhage was detected in only 7 patients by using conventional MRI, and none was detected by CT. In addition, CT demonstrated calcifications in 22 patients which were all detected by SWI whereas only 3 were detected by conventional MRI. Compared to CT, SWI showed 100% in the diagnostic sensitivity, specificity, accuracy, positive predictive value(PPV) and negative predictive value(NPV) in detecting calcifications in prostate but conventional MRI demonstrated 13.6% in sensitivity, 100% in specificity, 75% in accuracy, 100% in PPV and 74% in NPV. CONCLUSIONS: More apparent prostate hemorrhages were detected on SWI than on conventional MRI or CT. SWI may provide valuable information for the differential diagnosis between prostate cancer and prostatic hyperplasia. Filtered phase images can identify prostatic calcifications as well as CT.

Human patellar cartilage: echo planar diffusion-weighted MR imaging findings at 3.0 T.

PURPOSE: To explore the findings of diffusion-weighted imaging (DWI) and the diffusion characteristics on patellar cartilage in healthy adults. MATERIALS AND METHODS: Thirty healthy subjects were studied on SIEMENS 3.0-T Trio Tim magnetic resonance (MR) scanner. The apparent diffusion coefficient (ADC) values of the patellar cartilage were measured in different areas. RESULTS: The patellar cartilage demonstrated homogeneously high signal intensity on the images of DWI and maps of ADC. The ADC values displayed a spatial dependency, approximately (1.17 ± 0.31)×10(-3) mm(2)/s of the entire cartilage. CONCLUSIONS: Diffusion-weighted MR imaging may display articular cartilage structure. There is a consistent pattern of spatial variation of the ADC values.

Measurement of tumor size in adult glioblastoma: classical cross-sectional criteria on 2D MRI or volumetric criteria on high resolution 3D MRI?

OBJECTIVE: To investigate the added value of volume on post-contrast three dimensional (3D) T1-weighted image (T1WI) over classical cross-sectional area on two dimensional (2D) T1WI in evaluating tumor response in glioblastoma multiforme (GBM). METHODS: Tumor cross-sectional area and volume measurements were performed on 104 MRI studies from 42 adult patients with GBM on post-contrast 5 mm 2D T1WI and isotropic high resolution 3D T1WI, respectively. 52 pairs of MRI scans were analyzed for relative change. Radiographic responses were determined based on change in either area or volume. RESULTS: A high correlation was revealed between tumor size measured by area on thick 2D and volume on high resolution 3D MRI in 104 scans (r=0.82, p<0.001). When four tumor response criteria were used according to the percentage changes (complete response/partial response/stable disease/progression), the kappa coefficient between the area on 2D and volume on 3D was 0.68 (p<0.05) with an overall agreement of 81%. CONCLUSIONS: Tumor cross-sectional area on post-contrast 2D T1WI appears comparable to volume on 3D T1WI and should still be a practical alternate of volume on 3D for evaluating tumor response.

Distinction between postoperative recurrent glioma and delayed radiation injury using MR perfusion weighted imaging.

INTRODUCTION: Distinction between postoperative recurrent glioma and radiation injury remains a tough diagnostic problem for routine imaging methods. The purpose of this study is to evaluate the differentiated effectiveness of perfusion weighted imaging (PWI) for the two entities. METHODS: PWI was performed using Siemens 3.0-T MR system for 35 patients with new contrast-enhancing lesions at the site of treated glioma. Regions of interest (ROIs) were manually drawn at the contrast-enhancing lesion and peri-lesion edema areas. For calculation of standardised relative cerebral blood volume (rCBV) ratios, the same size ROIs were drawn at the area of contralateral hemisphere normal white matter on rCBV maps. At least five ROIs were selected at each lesion. The rCBV values were measured and the rCBV ratios were calculated. The maximum rCBV (rCBV(max)) ratio at each region was chosen for analysis. The patients were divided into two groups: tumour recurrence and radiation injury. The mean rCBV(max) ratios were compared between the two groups. RESULTS: The mean rCBV(max) ratio in the contrast-enhancing lesion was significantly higher in the tumour recurrence (4.36 ± 1.98) compared with that (1.28 ± 0.64) in the radiation injury (P < 0.01). The mean rCBV(max) ratio in the peri-lesion edema was also significantly higher in the tumour recurrence (1.79 ± 0.51) compared with that (0.85 ± 0.28) in the radiation injury (P < 0.05). A recurrent tumour was suggested when the rCBV(max) ratio >2.15 based on the receiver operating characteristic curve. Four patients with recurrent tumour and three with radiation injury were misclassified. CONCLUSION: PWI is a useful method to distinguish tumour recurrence and radiation injury.

Magnetic resonance spectroscopy in the diagnosis of cognitive impairment in AIDS patients.

BACKGROUND: The pathological abnormalities of the AIDS patients lie in the subcortical regions of the brain, specifically the deep white matter and basal ganglia, while the extent of pathology generally correlates with the severity of cognitive impairments in the white matter and basal ganglia. Brain metabolite changes of these lesions can reflect the pathological abnormalities. The purpose of this study was to assess the value of magnetic resonance spectroscopy (MRS) in the diagnosis of cognitive impairment in AIDS patients. METHODS: 3.0T MR was used to measure N-acetyl aspartate (NAA), choline (Cho), myo-inositol (MI) and creatinine (Cr) in the frontal white matter, basal ganglia and parietal cortex of 21 AIDS patients with dementia complex (ADC), 19 AIDS patients with neuroasymptomatic (NAS) and 20 seronegative (SN) controls. Then we compared the difference of metabolic rate between AIDS patients and SN groups. RESULTS: NAA/Cr (mean = 1.2502, SD = 0.1600) was significantly decreased and Cho/Cr (mean = 1.2028, SD = 1.1655) was increased in the frontal white matter in ADC group, while NAA/Cr (mean = 1.5334, SD = 0.0513) was reduced in NAS group when compared with SN group. NAA/Cr in the basal ganglia was decreased in both ADC and NAS groups (mean = 1.2625, SD = 0.1615 and mean = 1.5278, SD = 0.0380, respectively). Cho/Cr (mean = 1.1631, SD = 0.0981) was markedly increased in ADC group. Although NAA/Cr, Cho/Cr and MI/Cr in the parietal cortex had a certain change in both ADC and NAS groups compared with SN group, the differences were not statistically significant. CONCLUSIONS: The brain metabolite changes of AIDS patients are correlated with cognitive impairments. MRS can be used as a valuable inspection method to assess cognitive impairments in AIDS patients.

Comparison of volumetric methods for tumor measurements on two and three dimensional MRI in adult glioblastoma.

INTRODUCTION: Change in tumor size is a frequent endpoint in cancer clinical trials, but whether change in size should be measured using volume on two-dimensional (2D) or three-dimensional (3D) images is not certain. We compared volumetric measurements on post-contrast 2D and high-resolution 3D T1-weighted MR images (T1WI) in evaluating tumor response in glioblastoma multiforme (GBM). METHODS: Tumor volume measurements were performed on 86 MRI studies from 37 adult patients with GBM on post-contrast 5 mm 2D T1WI and isotropic high-resolution T1WI. The means of the two volumes were compared and their association was analyzed. RESULTS: There is no significant difference between volumes measured on 2D and 3D in 86 scans (Z = 0.63, p = 0.53), and a high correlation was revealed between them (r = 0.95, 95% CI: 0.93-0.97, p < 0.001). When the percentage changes were categorized into traditional tumor response criteria (complete response/partial response/stable disease/progressive disease), the kappa coefficient between the volume on 2D and volume on 3D was 0.80 (95% CI: 0.57-1.03, p < 0.05) with an overall agreement of 84%. CONCLUSIONS: Volume on post-contrast 2D T1WI appears comparable to volume on 3D T1WI and should be a practical alternative to volume on 3D in evaluating tumor response.

Non-enhanced MR angiography of renal artery using inflow-sensitive inversion recovery pulse sequence: a prospective comparison with enhanced CT angiography.

PURPOSE: To prospectively evaluate the diagnostic value of non-enhanced inflow-sensitive inversion recovery (IFIR) MR angiography for the detection of renal artery stenosis (RAS), with enhanced CT angiography performed as the reference standard. MATERIALS AND METHODS: Sixty consecutive patients suspected of RAS underwent both of IFIR MR and enhanced CT angiography. Subjective image quality, renal artery depiction and renal artery grading were all evaluated on artery-by-artery basis. Spearman rank correlation analysis was used to assess agreement between the two techniques. The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for RAS detection at IFIR MR angiography were calculated. RESULTS: One hundred twenty-six main renal arteries were visualized on enhanced CT and non-enhanced MR angiographic images, respectively. The Spearman rank correlation was 0.773 (P<.001) for renal artery depiction, 0.998 (P<.001) for renal arteries grading and 0.833 (P<.001) for RAS detection between the two modalities. The sensitivity, specificity, PPV and NPV of IFIR MR angiography for RAS detection demonstrated 100%, 99.0%, 92.0% and 100%, respectively. CONCLUSION: Non-enhanced IFIR MR angiography had high sensitivity, specificity, PPV and NPV for RAS detection. It could be the first choice of renal artery imaging methods to avoid ionizing irradiation and renal toxicity from contrast media.

Distinction between postoperative recurrent glioma and radiation injury using MR diffusion tensor imaging.

INTRODUCTION: This study aims to evaluate the differentiated effectiveness of MR diffusion tensor imaging (DTI) to postoperative recurrent glioma and radiation injury. METHODS: Conventional MRI and DTI examination were performed using Siemens 3.0 T MR System for patients with new contrast-enhancing lesions at the site of treated tumor with postoperative radiotherapy. The region of interest was manually drawn on ADC and FA maps at contrast-enhancing lesion area, peri-lesion edema, and the contra-lateral normal white matter. Then ADC and FA values were measured and, the ADC ratio and FA ratio were calculated. Twenty patients with recurrent tumor and 15 with radiation injury were confirmed by histopathologic examination (23 patients) and clinical imaging follow-up (12 patients), respectively. The mean ADC ratio and FA ratio were compared between the two lesion types. RESULTS: The mean ADC ratio at contrast-enhancing lesion area was significantly lower in patients with recurrent tumor (1.34 ± 0.15) compared to that with radiation injury (1.62 ± 0.17; P < 0.01). The mean FA ratio at contrast-enhancing lesion area was significantly higher in patients with recurrent tumor (0.45 ± 0.03) compared to that with radiation injury (0.32 ± 0.03; P < 0.01). Neither mean ADC ratio nor FA ratio in edema areas had statistical difference between the two groups. A recurrent tumor was suggested when either ADC ratio <1.65 or/and FA ratio >0.36 at contrast-enhancing lesion area according to the receiver operating characteristics curve analysis. Three patients with recurrent tumor and two with radiation injury were misclassified. CONCLUSION: DTI is a valuable method to distinguish postoperative recurrent glioma and radiation injury.

Epiphyseal and physeal injury: comparison of conventional radiography and magnetic resonance imaging.

PURPOSE: To compare conventional radiography and magnetic resonance imaging (MRI) in the assessment of epiphyseal and physeal injury. MATERIALS AND METHODS: Seventeen cases with epiphyseal and physeal injury were examined with conventional radiography and MRI. Two blinded experienced radiologists separately evaluated the results retrospectively. RESULTS: Two Salter-Harris II fractures showed displacement of epiphysis and metaphyseal fragment, as well as T1 hypointensity and T2 hyperintensity in the physis on MRI. Three Salter-Harris IV fractures showed a fracture line in the epiphysis and metaphysis on two modalities, as well as linear T2 hyperintensity in the physis. All five slipped epiphysis showed signal intensity abnormality in the physis on MRI aside from the physeal widening and epiphyseal displacement seen on radiographs. Seven patients with bony bridge formation showed premature closure of the physis, shortening, and remodeling of the end of bones involved. CONCLUSIONS: Conventional radiography and MRI are both useful in the diagnosis of epiphyseal and physeal injury. MRI can provide more detailed information, which could direct treatment planning and prognosis predicting.

[Comparison of ultrasound biomicroscopy and CT in diagnosis of anterior segment intraocular foreign body].

OBJECTIVE: To report the appearance of anterior segment intraocular foreign body in ultrasound biomicroscopy (UBM) and CT. To investigate the advantage and disadvantage of these two imaging methods and to evaluate the value of combining application of these methods in the diagnosis of anterior segment intraocular foreign body. METHODS: It was a comparative study. Forty-four cases of suspected anterior segment intraocular foreign body were simultaneously examined by UBM and CT from July 2000 to May 2007, the results were compared with the operation results. RESULTS: In 44 cases examined by CT, foreign bodies in 40 cases showed high density shadows, including iron, copper, stone and other foreign bodies; 2 cases showed slightly high density shadow, which were identified as plastics; in 2 cases, the foreign bodies could not be detected by CT, which were bamboo pick and Chinese chestnut sting. It was difficulty to locate the foreign body exactly and to detect the complications of anterior segment intraocular foreign body by using CT. All 44 cases of anterior segment intraocular foreign body showed strong echo spot with acoustic shadow in the UBM. UBM could provide the exact location of foreign body and could detect all complications. But the examining procedure of UBM was complicated, the examining screen was relatively narrow and the examination was time-consuming. CONCLUSION: In suspected anterior segment intraocular foreign body, CT examination should be performed first to detect the position and the nature of foreign body, then UBM could be used to obtain the exact position of foreign body and to detect the complications.