Abnormal amplitude of low frequency fluctuation and functional connectivity in non-neuropsychiatric systemic lupus erythematosus: a resting-state fMRI study.

PURPOSE: To explore the amplitude of low frequency fluctuation (ALFF) and functional connectivity (FC) disorders in non-neuropsychiatric systemic lupus erythematosus (non-NPSLE) patients by resting-state functional magnetic resonance imaging (rs-fMRI) and to study whether there are some clinical biomarkers that can be used to monitor the brain dysfunction. METHODS: Based on the rs-fMRI data of 36 non-NPSLE patients and 30 normal controls, we first obtained the regions with abnormal ALFF signals in non-NPSLE patients. Then, by taking these areas as seed regions of interest (ROIs), we calculated the FC between ROIs and the whole brain to assess the network-level alterations. Finally, we correlated the altered values of ALFF and FC in non-NPSLE patients to some clinical data. RESULTS: Compared with the controls, non-NPSLE patients showed decreased ALFF in bilateral precuneus and increased ALFF in right cuneus and right calcarine fissure surrounding cortex (CAL). At network level, non-NPSLE patients exhibited higher FC between left precuneus and left middle occipital gyrus (MOG)/left superior occipital gyrus (SOG)/right middle frontal gyrus (MFG)/right dorsolateral superior frontal gyrus (SFGdor), and higher FC between right cuneus and bilateral precuneus/left posterior cingulate gyrus (PCG). The abnormal ALFF in right CAL and abnormal FC in right cuneus-left precuneus, right cuneus-right precuneus, and right cuneus-left PCG were correlated with the patients' certain clinical data (p < 0.05). CONCLUSION: Rs-fMRI is a promising tool for detecting the brain function disorders in non-NPSLE patients and to help understand the neurophysiological mechanisms. C4 and Systemic Lupus Erythematosus Disease Activity Index may be biomarkers of brain dysfunction in non-NPSLE patients.

Computed tomographic perfusion imaging for the therapeutic response of chemoembolization for hepatocellular carcinoma.

BACKGROUND: Computed tomographic (CT) perfusion imaging has been applied in many clinical areas, but few studies have addressed the values of CT perfusion imaging in evaluating the therapeutic response of chemoembolization for hepatocellular carcinoma (HCC). OBJECTIVE: To assess the perfusion changes of HCC after transarterial chemoembolization, and to investigate the values of CT perfusion imaging in chemoembolization procedure. METHODS: Multidetector computed tomographic perfusion imaging was performed in 24 patients with HCC 1 week before and 4 weeks after chemoembolization. The CT perfusion parameters, including hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP), total liver perfusion (TLP), and hepatic arterial perfusion index (HAPI), were calculated by using the slope method. The t statistic was used to analysis the difference of CT perfusion parameter values before and after chemoembolization therapy. RESULTS: The values of HAP, TLP, and HAPI in tumors 4 weeks after chemoembolization were significantly decreased than those before chemoembolization (P < 0.05), but the value of HPP in tumors was not (P > 0.05). CONCLUSION: Computed tomographic perfusion imaging has the ability to evaluate the perfusion changes in HCC after chemoembolization, which can be used to evaluate the therapeutic response of chemoembolization for hepatocellular carcinoma.

Correlation between tumor perfusion and lipiodol deposition in hepatocellular carcinoma after transarterial chemoembolization.

PURPOSE: To study the correlation of tumor perfusion with lipiodol deposition in hepatocellular carcinoma (HCC) after transarterial chemoembolization with multidetector computed tomography (MDCT) perfusion imaging. MATERIALS AND METHODS: MDCT perfusion imaging was performed in 24 patients with HCC 1 to 7 days before chemoembolization. The computed tomography (CT) perfusion parameters, such as hepatic arterial perfusion (HAP), hepatic portal perfusion (HPP), total liver perfusion (TLP), and hepatic arterial perfusion index (HAPI), were calculated with the slope method. The follow-up CT scans (noncontrast) were performed 4 weeks after chemoembolization to analyze lipiodol deposition. The lipiodol deposition in the tumor was classified into three grades and compared with CT perfusion parameters before chemoembolization. RESULTS: The HAP and TLP of tumors before chemoembolization were correlated with the grades of lipiodol deposition in tumors after chemoembolization (r = 0.768, P < .0001 and r = 0.616, P = .001, respectively). However, the HPP and HAPI of the tumors were not related to the grades of iodized oil deposition (r = 0.227, P = .286 and r = 0.111, P = .607, respectively). Higher HAP was correlated with better lipiodol deposition, and lower HAP was correlated with poorer lipiodol deposition. CONCLUSIONS: MDCT perfusion imaging has the potential to help select more appropriate patients with HCC for chemoembolization.

MR venography of the inferior mesentery vein.

OBJECTIVE: To evaluate on three-dimensional (3D) dynamic contrast-enhanced (DCE) MR venography (MRV), the visibility of the inferior mesenteric vein (IMV), its insertion pattern into the portal system, and the difference of IMV diameters between healthy subjects and patients with cirrhosis. MATERIALS AND METHODS: Two hundred and seventeen consecutive patients who had abdominal 3D DCE MRI was included in this study. The original image data of 3D DCE MRI was used to generate multiple planar volume reconstruction (MPVR) images, which were evaluated for visualization of the IMV and its pattern of insertion into the portal system. The diameter of IMV was measured and compared in 24 patients with cirrhosis (Cirrhosis Group) and in 30 patients without hepatic lesions or liver disease (Healthy Group). RESULTS: In the 217 patients, the frequencies of visualization of IMV, grade 1 order branches and grade 2 order branches were, respectively, 88%, 24% and 9%. The IMV inserted into the splenic vein (SV), the portal confluence and the superior mesenteric vein (SMV) in 45%, 18% and 37%, respectively. Among patients with cirrhosis, 12.5% had IMV diameter larger than 5.1mm, although there was no significant difference between cirrhosis and healthy groups (P>0.05). However, the diameters of the main portal vein (MPV), SV and SMV were significantly larger in the Cirrhosis Group (P<0.05). CONCLUSION: The IMV and its branches can be depicted well by 3D DCE MRV. The most common insertion of the IMV is into the splenic vein. A minority of patients with cirrhosis had dilatation of the IMV.

Patterns of portosystemic collaterals and diameters of portal venous system in cirrhotic patients with hepatitis B on magnetic resonance imaging: Association with Child-Pugh classifications.

BACKGROUND AND OBJECTIVE: To determine associations of patterns of portosystemic collaterals and diameters of portal venous system in cirrhotic patients with hepatitis B on magnetic resonance (MR) imaging with Child-Pugh classification. MATERIALS AND METHODS: Eighty-eight consecutive patients with cirrhosis resulting from chronic hepatitis B graded by Child-Pugh classifications were recruited and undergone MR portography. Patterns of the collaterals (presented as no collateral, isolated esophageal varices, and esophageal varices combined with other shunts), and diameters of portal venous system including portal vein (PV), left portal vein (LPV), right portal vein (RPV), splenic vein (SV) and superior mesenteric vein (SMV) were assessed statistically to determine associations of patterns of collaterals and diameters of the portal veins with Child-Pugh classification. RESULTS: From no collateral, to isolated esophageal varices, and to the varices combined with other shunts, the Child-Pugh classifications tended to increase (r=0.516, P<0.001). Diameters of PV, LPV, RPV, SV and SMV tended to increase from Child-Pugh A to B but decrease from B to C. Differences in diameter of LPV and SV were significant between Child-Pugh A-B and C (all P<0.05) while no differences in diameters of other portal veins were found (all P>0.05). For discriminating Child-Pugh A-B from C, either a cut-off LPV diameter of 8.98mm or SV diameter of 9.10mm achieved a sensitivity of 67%-70%, specificity of 51%-53%. CONCLUSION: Patterns of portosystemic collaterals and diameters of LPV and SV tend to be associated with Child-Pugh classifications of cirrhosis.

Hepatic abnormal perfusion visible by magnetic resonance imaging in acute pancreatitis.

AIM: To study the prevalence and patterns of hepatic abnormal perfusion (HAP) visible by magnetic resonance imaging (MRI) in acute pancreatitis (AP). METHODS: Enhanced abdominal MRI was performed on 51 patients with AP. These patients were divided into two groups according to the MRI results: those with signs of gallstones, cholecystitis, common bile duct (CBD) stones or dilatation of the CBD on MRI and those without. The prevalence, shape and distribution of HAP in the two groups were analyzed and compared. The severity of AP was graded using the MR severity index (MRSI). The correlation between the MRSI and HAP was then analyzed. RESULTS: Of the 51 patients with AP, 32 (63%) showed at least one sign of gallbladder and CBD abnormalities on the MR images, while 19 (37%) showed no sign of gallbladder or CBD abnormalities. Nineteen patients (37%) had HAP visible in the enhanced images, including strip-, wedge- or patch-shaped HAP distributed in the hepatic tissue adjacent to the gallbladder and left and right liver lobes. There were no significant differences in the prevalence of HAP (χ (2) = 0.305, P = 0.581 > 0.05) or HAP distribution in the liver (χ (2) = 2.181, P = 0.536 > 0.05) between patients with and without gallbladder and CBD abnormalities. There were no significant differences in the MRSI score between patients with and without HAP (t = 0.559, P = 0.552 > 0.05). HAP was not correlated with the MRSI score. CONCLUSION: HAP is common in patients with AP and appears strip-, patch- or wedge-shaped on MRI. HAP on MRI cannot be used to indicate the severity of AP.

MRI findings of otic and sinus barotrauma in patients with carbon monoxide poisoning during hyperbaric oxygen therapy.

BACKGROUND AND PURPOSE: To study the MRI findings of otic and sinus barotrauma in patients with carbon monoxide(CO) poisoning during hyperbaric oxygen (HBO) therapy and examine the discrepancies of otic and sinus abnormalities on MRI between barotrauma and acute otitis media with effusion. MATERIALS AND METHODS: Eighty patients with CO-poisoning diagnosed with otic and sinus barotrauma after HBO therapy were recruited. Brain MRI was performed to predict delayed encephalopathy. Over the same period, 88 patients with acute otitis media with effusion on MRI served as control. The abnormalities of the middle ear and paranasal sinuses on MRI were noted and were compared between groups. Nine patients with barotrauma were followed up by MRI. RESULTS: In the barotrauma group, 92.5% of patients had bilateral middle ear abnormalities on MRI, and 60% of patients had both middle ear cavity and mastoid cavity abnormalities on MRI in both ears. Both rates were higher than those in the control group (p = 0.000). In the two groups, most abnormalities on MRI were observed in the mastoid cavity. The rate of sinus abnormalities of barotrauma was 66.3%, which was higher than the 50% in the control group (p = 0.033). In the nine patients with barotrauma followed up by MRI, the otic barotrauma and sinus abnormalities had worsened in 2 patients and 5 patients, respectively. CONCLUSION: MRI is able to depict the abnormalities of otic and sinus barotrauma in patients with CO-poisoning during HBO therapy and to differentiate these from acute otitis media with effusion.

Gallbladder patterns in acute pancreatitis: an MRI study.

RATIONALE AND OBJECTIVES: The aim of this study was to assess the gallbladder patterns on magnetic resonance imaging (MRI) associated with acute pancreatitis (AP). MATERIALS AND METHODS: There were 197 patients with AP, all of whom had undergone abdominal MRI. AP was categorized as either edematous or necrotizing according to its findings on MRI and graded as mild (0-3 points), moderate (4-6 points), or severe (7-10 points) according to the magnetic resonance severity index. The changes to the walls and dimensions of the gallbladder and common bile duct, in addition to the presence of biliary stones and pericholecystic fluid, were noted and compared with the severity of AP on the basis of the magnetic resonance severity index. RESULTS: Of the 197 patients with AP, 81% were classified as edematous and 19% as necrotizing on MRI. There were 35%, 59%, and 6% of patients with mild, moderate, and severe AP according to the magnetic resonance severity index, respectively. Seventy-six percent of patients had at least one gallbladder abnormality on MRI, including a thickened gallbladder wall (42%), pericholecystic fluid (38%), gallbladder stones (35%), an enlarged gallbladder (24%), dilatation of the common bile duct (16%), and subserosal edema (15%). Eighty-nine percent of patients (34 of 38) with necrotizing AP had gallbladder abnormalities, which was significantly higher than the 72% of patients (115 of 159) with edematous AP (P < .05). The prevalence of gallbladder abnormalities was 64% in patients with mild AP, 81% in those with moderate AP, and 91% in those with severe AP (P < .05 among the three groups). CONCLUSIONS: Most patients with AP have gallbladder abnormalities on MRI, including a thickened gallbladder wall and pericholecystic fluid. The prevalence of gallbladder abnormalities has a positive correlation with the severity of AP on MRI.

Renal and perirenal space involvement in acute pancreatitis: An MRI study.

OBJECTIVES: To study the prevalence and characteristics of renal and perirenal space involvement and its relation to the severity of acute pancreatitis (AP) using MRI. METHODS: 115 patients with AP who underwent MRI with the clinical kidney function test were retrospectively analyzed in this study. MRI sequences included conventional and diffusion weighted imaging (DWI) sequences. The renal and perirenal space involvement in AP was noted on MRI. The renal apparent diffusion coefficient (ADC) on DWI was measured for each kidney. The severity of AP on MRI was graded using MR severity index (MRSI). The relationships among the renal and perirenal space involvement on MRI, the renal ADC, MRSI and the results of the kidney function test were analyzed. RESULTS: In the 115 patients with AP, the renal and perirenal space abnormalities detected included renal parenchymal abnormalities (0.8%), abnormalities of the renal collecting system (2.6%), renal vascular abnormalities (1.7%), thickened renal fascia (99%), perirenal stranding (62%) and perirenal fluid collection (40%). The prevalence of perirenal space abnormalities was correlated with the severity of AP based on MRSI (P<0.05). The renal ADC values were lower in patients with abnormal kidney function than in those without kidney injury (P<0.05). The prevalence of kidney function abnormalities was 9.4%, 32% and 100% in mild, moderate, and severe AP cases, respectively (P=0.00). CONCLUSION: Perirenal space involvement is much more than renal parenchymal involvement in AP. The prevalence of perirenal space involvement in AP on MRI has a positive correlation with the severity of AP according to MRSI.

Hepatic caudate vein in Budd-Chiari syndrome: depiction by using magnetic resonance imaging.

OBJECTIVE: To study the visibility of the caudate vein and its diameter on MR imaging in healthy people and in patients with Budd-Chiari syndrome. MATERIALS AND METHODS: In this study there were 14 patients with Budd-Chiari syndrome and 54 healthy subjects without hepatic lesion or liver disease, all of whom had upper abdominal enhanced MRI. The visibility of the caudate vein and its diameter on MR images was compared between Budd-Chiari patients and healthy subjects, and among Budd-Chiari patients, the correlation between the visibility of caudate vein and extrahepatic collaterals were compared. RESULTS: Caudate vein was noted in 64% of patients with Budd-Chiari syndrome and in 7% of healthy subjects (P=0.000). The diameter of the caudate vein visualized on MR imaging in Budd-Chiari syndrome was significantly larger than that in healthy group (7.3±3.9 mm vs 2.6±0.6 mm, P=0.037). Among Budd-Chiari patients, both caudate vein and extrahepatic collateral veins were noted in 9 patients, only extrahepatic collateral veins were noted in 4 patients and neither caudate vein nor extrahepatic collateral veins were noted in 1 patient. No correlation was found between the visibility of caudate vein and that of extrahepatic collateral vein in patients with Budd-Chiari (P=0.375). CONCLUSION: Gadolinium enhanced dynamic MR imaging can visualize hepatic caudate vein frequently. The visibility and dilation of hepatic caudate veins on MR imaging in Budd-Chiari syndrome were more frequent than in control subjects. MR depiction of a caudate vein may help differentiate Budd-Chiari from cirrhosis.

Magnetic resonance imaging for local complications of acute pancreatitis: a pictorial review.

Acute pancreatitis is a common disease characterized by sudden upper abdominal pain and vomiting. Alcoholism and choledocholithiasis are the most common factors for this disease. The choice of treatment for acute pancreatitis might be affected by local complications, such as local hemorrhage in or around the pancreas, and peripancreatic infection or pseudoaneurysm. Diagnostic imaging modalities for acute pancreatitis have a significant role in confirming the diagnosis of the disease, helping detect the extent of pancreatic necrosis, and for diagnosing local complications. Magnetic resonance imaging (MRI) might be indicated in acute pancreatitis for detecting and characterizing local complications of acute pancreatitis that involve necrotic, hemorrhagic, infectious, vascular, and pseudocyst disorders. The general MRI sequences for pancreatitis require the combined use of T1-weighted, T2-weighted sequences, and magnetic resonance cholangiopancreatography. For imaging of pancreatic necrosis, the combination of T1-weighted and T2-weighted findings with dynamic contrast-enhanced imaging gives a comprehensive evaluation of the extent of necrosis and full range of inflammatory extension. For imaging of infectious complications, dynamic contrast-enhanced examinations might help differentiate pancreatic cellulitis or abscesses, from pancreatic fluid collection or simple pseudocysts. For vascular abnormalities, the combination of cross-sectional pancreatic parenchyma imaging with MRA represents a single diagnostic modality for the full evaluation of peripancreatic artery and vein involvement, such as arterial pseudoaneurysms and venous thromboses. The purpose of this pictorial review is to examine the MRI appearances of various local complications of acute pancreatitis and to discuss the practical setup of MRI in local complications of acute pancreatitis.

DCE-MRI in experimental chronic pancreatitis.

To assess pancreatic perfusion in experimental chronic pancreatitis (CP) by dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). DCE MRI on a 1.5 T MR scanner was performed on 21 piglets with the ligation of pancreatic duct. They were divided into four groups based on pathology, including seven normal pigs and seven, three and four piglets with grade I, II and III CP, respectively. The signal intensity measured in the pancreatic body on DCE MRI was plotted against time to create a signal intensity-time (SI-T) curve for each piglet. The steepest slope (SS), time-to-peak (TTP) and peak enhancement ratio (PER) of the SI-T curve were noted. In the four groups, on the SI-T curve derived from DCE MRI, the SS was, respectively, 10.88 +/- 1.20, 10.59 +/- 1.02, 6.67 +/- 1.31 and 5.48 +/- 1.97%/s (F = 20.509, p = 0.000) from normal piglets to piglets with grade III CP. The TTP was 13.82 +/- 3.09, 12.31 +/- 5.52, 20.55 +/- 3.79 and 37.26 +/- 14.56 s (F = 10.681, p = 0.000) and the PER was 62.95 +/- 20.20, 60.44 +/- 20.00, 46.33 +/- 22.70 and 67.65 +/- 32.66% (F = 0.529, p = 0.668), respectively. The SS (r = -0.719, p = 0.000) and TTP (r = 0.538, p = 0.012) of the SI-T curve was correlated to the severity of CP, respectively. DCE MRI has a potential to diagnose moderate to advanced CP. The SS and TTP of the SI-T curve were correlated to the severity of CP.