Fatty liver on computed tomography scan on admission is a risk factor for severe coronavirus disease.

OBJECTIVES: To alleviate the overflow of coronavirus disease 2019 (COVID-19) patients in hospitals, less invasive and simple criteria are required to triage the patients. We evaluated the relationship between COVID-19 severity and fatty liver on plain computed tomography (CT) scan performed on admission. METHODS: In this retrospective cohort study, we considered all COVID-19 patients at a large tertiary care hospital between January 31 and August 31, 2020. COVID-19 severity was categorized into severe (moderate and severe) and non-severe (asymptomatic and mild) groups, based on the Japanese National COVID-19 guidelines. Fatty liver was detected on plain CT scan. Multivariate logistic regression analysis was performed to evaluate factors associated with severe COVID-19. RESULTS: Of 222 patients (median age: 52 years), 3.2%, 58.1%, 20.7%, and 18.0% presented with asymptomatic, mild, moderate, and severe COVID-19, respectively. Although 59.9% had no fatty liver on plain CT, mild, moderate, and severe fatty liver occurred in 13.1%, 18.9%, and 8.1%, respectively. Age and presence of fatty liver were significantly associated with severe COVID-19. CONCLUSION: Our study showed that fatty liver on plain CT scan on admission can become a risk factor for severe COVID-19. This finding may help clinicians to easily triage COVID-19 patients.

Clinical and radiological findings of silent hypoxia among COVID-19 patients.

The aim of this study was to describe the clinical and radiological findings of COVID-19 patients with "silent hypoxia," who had no dyspnea on admission even though their oximetry saturation was less than 94%. This retrospective cohort study included all COVID-19 patients (n = 270) at a large tertiary care hospital between January 31 and August 31, 2020. Clinical and radiological characteristics of patients who met our criteria of "silent hypoxia", which included those who reported no dyspnea even though oximetry saturation was <94%, were extracted. Eight patients (3.0%) met the criteria for "silent hypoxia." The median age was 61 years (interquartile range [IQR]: 48.8-72.3), and five (62.5%) were men. All patients had consolidation on CT and showed a moderate to high COVID-19 CT severity score (median: 13.5, IQR: 10.8-15.3). The median FIO2 of the maximum oxygen required was 55 (IQR: 28-70)%. Two patients (25.0%) were intubated, and one patient (12.5%) underwent extracorporeal membrane oxygenation. Some COVID-19 patients with "silent hypoxia" may develop severe disease. Close and accurate monitoring of patients using arterial blood gas and pulse oximetry is necessary, regardless of their symptoms.

Diagnosis of celiac artery stenosis using multidetector computed tomography and evaluation of the collateral arteries within the mesopancreas of patients undergoing pancreaticoduodenectomy.

INTRODUCTION: Celiac artery (CA) stenosis (CAS), caused by various factors, is often asymptomatic because collateral blood flow from the superior mesenteric artery supplies the CA outflow region. The purpose of this study was to investigate the usefulness of multidetector computed tomography (MDCT) for diagnosing CAS and associated collateral artery formation, and elucidating the effect of CAS on the numbers and diameters of the arteries within the mesopancreas. MATERIALS AND METHODS: We investigated 106 patients who underwent contrast-enhanced MDCT, before pancreaticoduodenectomy, between January 2015 and September 2019. MDCT was used to determine the percentage stenosis of the CAs; patients were classified into CAS (-) (0-29% stenosis) and CAS (+) (30-100% stenosis) groups. The dissection lines of the mesopancreas were classed as Level I or II, and the numbers and diameters of the arteries along each dissection line were counted and measured. RESULTS: There were 27 CAS (+) patients and 79 CAS (-) patients. In the CAS (+) group there were more arteries and they had larger diameters than those in the CAS (-) group, at both Levels I and II. There were significantly more arteries when the CA stenosis was ≥30% and they had larger diameters when the stenosis was ≥50%. CONCLUSIONS: MDCT is useful for diagnosing CAS, and CAS is associated with larger numbers and diameters of the arteries within the mesopancreas.

Pseudomyxoma peritonei: visceral scalloping on CT is a predictor of recurrence after complete cytoreductive surgery.

OBJECTIVES: Pseudomyxoma peritonei (PMP) is characterized by peritoneal dissemination of gelatinous ascites following rupture of a mucinous tumor. Treatment by cytoreductive surgery (CRS) has improved its prognosis. Although visceral scalloping, notably liver scalloping, on computed tomography (CT) is a typical feature of PMP, its prognostic value remains unknown. We aimed to investigate the efficacy of liver scalloping in predicting recurrence in PMP patients. METHODS: Among 159 consecutive patients with PMP who had contrast-enhanced CT between September 2012 and December 2018, 64 treatment-naïve patients who subsequently underwent CRS with complete resection (i.e., completeness of cytoreduction score (CC)-0 or CC-1), were included in analysis. Presence of liver scalloping and maximum thickness of mucin deposition at the liver surface were evaluated on CT. Disease-free survival (DFS) was determined based on the combination of postoperative CT features and tumor marker values. RESULTS: Median follow-up was 24.3 months. CT revealed liver scalloping in 40/64 (63.4%) patients. Kaplan-Meier analysis showed significantly shorter DFS in patients with scalloping than in those without (p = 0.001; hazard ratio, 4.3). In patients with scalloping, greater mucin deposition (thickness ≥ 20 mm) significantly correlated with poorer DFS (p = 0.042). In multivariate Cox proportional hazards regression including CC status, pathologic type, and tumor markers, the presence of scalloping independently and significantly correlated with DFS (p = 0.031). CONCLUSIONS: Liver scalloping was an independent predictor even after adjusting for clinical covariates. The presence of liver scalloping can lead to a high recurrence rate after CRS. KEY POINTS: • The presence of liver scalloping is a prognostic factor independent of histological grade and tumor markers. • Greater mucin deposition (thickness ≥ 20 mm at the liver surface) is associated with higher recurrence rates in patients with liver scalloping.

Validation of the American Gastroenterological Association guidelines on management of intraductal papillary mucinous neoplasms: more than 5 years of follow-up.

OBJECTIVES: Recent guidelines suggest that imaging surveillance be conducted for 5 years for patients with at most one high-risk feature. If there were no significant changes, surveillance is stopped. We sought to validate this follow-up strategy. METHODS: In study 1, data were analysed for 392 patients with intraductal papillary mucinous neoplasms (IPMNs) and at most one high-risk feature who were periodically followed up for more than 1 year with imaging tests. In study 2, data were analysed for 159 IPMN patients without worsening high-risk features after 5 years (stop surveillance group). RESULTS: In study 1, pancreatic cancer (PC) was identified in 12 patients (27.3%) in the endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) indication group and none in the non-EUS-FNA indication group (P < 0.01). In the EUS-FNA indication group, 11 patients (25%) died, whereas 29 (8.3%) died in the non EUS-FNA indication group (P < 0.01). In study 2 (stop surveillance group), PC was identified in three patients (1.9%) at 84, 103 and 145 months. CONCLUSIONS: PC risk and mortality for IPMNs not showing significant change for 5 years is likely to be low, and the non-EUS-FNA indication can provide reasonable decisions. However, three patients without worsening high-risk features for 5 years developed PC. The stop surveillance strategy should be reconsidered. KEY POINTS: • The AGA guidelines provide reasonable clinical decisions for the EUS-FNA indication. • In stop surveillance group, PC was identified in 3 patients (1.9%). • In stop surveillance group, 2 of 3 PC patients died from PC. • Risk of pancreatic cancer in "stop surveillance" group is not negligible.

Short-Term Safety and Efficacy of Balloon-Occluded Retrograde Transvenous Obliteration Using Ethanolamine Oleate: Results of a Prospective, Multicenter, Single-Arm Trial.

PURPOSE: To evaluate 90-day outcomes after balloon-occluded retrograde transvenous obliteration (BRTO) with ethanolamine oleate (EO) in patients with gastric varices (GVs). MATERIALS AND METHODS: An 8-site prospective single-arm clinical trial was conducted. Patients who had endoscopically confirmed GVs with a gastrorenal shunt were eligible for the study. Overnight BRTO was performed, and efficacy was evaluated by endoscopy and contrast-enhanced computed tomography (CT). RESULTS: Forty-five patients (26 men and 19 women; mean age, 67.8 y) were enrolled. The complete regression rate of GVs based on endoscopic images on day 90 was 79.5% (35 of 44 patients; 95% confidence interval, 64.7%-90.2%). The rate of complete thrombosis of GVs based on contrast-enhanced CT on day 90 was 93.0% (40 of 43 patients; 95% confidence interval, 80.9%-98.5%). One patient experienced 2 events of bleeding from GVs, which was different from the GVs treated with BRTO. Appearance of new esophageal varices (EVs) or worsening of existing EVs occurred in 16 of 45 patients (35.6%). Forty-four of 45 patients (97.8%) experienced adverse events (AEs) related to EO, which included fever in 24 (53.3%), hematuria in 23 (51.1%), hemolysis in 16 (35.6%), back pain in 16 (35.6%), and abdominal pain in 10 (22.2%). One case of moderate to severe ascites (2.3%) was observed on day 90. One case of sepsis was the only serious AE observed in relation to EO. CONCLUSIONS: The present study demonstrates that BRTO with EO for the treatment of GVs is a clinically effective procedure with many mild to moderate AEs.

Accuracy analysis of intrahepatic fat density measurements using dual-energy computed tomography: Validation using a test phantom.

BACKGROUND: Currently, no standardized method for measuring intrahepatic fat density via conventional computed tomography (CT) exists. OBJECTIVE: We aim to quantify intrahepatic fat density via material decomposition analysis using rapid kilovolt peak-switching dual-energy (RSDE) CT. METHODS: Homogenized porcine liver and fat (lard) were mixed in various ratios to produce phantoms for fat density verification. The actual fat density was measured on the basis of the phantom volume and weight, and these measurements were used as reference densities. The fat and liver mass attenuation coefficients, which were used as the material basis pairs, were employed in the material decomposition analysis. Then, the measured fat density of each phantom was compared with the reference densities. RESULTS: For fat content differences exceeding 2%, the measured fat density for the phantoms became statistically significant (p < 0.01). The correlation between the reference densities and RSDE-measured fat densities was reasonably high (R > 0.9997); this indicates the validity of this analysis method. CONCLUSIONS: Intrahepatic fat density can be measured using the mass attenuation coefficients of fat and liver in a material decomposition analysis. Given the knowledge of the accuracy and the limitations found in this study, our method can quantitatively evaluate fat density.

Early postoperative screening by contrast-enhanced CT and prophylactic embolization of detected pseudoaneurysms prevents delayed hemorrhage after partial nephrectomy.

PURPOSE: To evaluate retrospectively whether prophylactic embolization of pseudoaneurysms detected on early postoperative screening with computed tomography (CT) after partial nephrectomy can prevent delayed hemorrhage. MATERIALS AND METHODS: Between January 2012 and May 2014, early postoperative contrast-enhanced CT was performed 3-5 days after partial nephrectomy in 312 patients (group A); CT was not performed in 65 patients (group B) because of renal insufficiency or contrast medium allergy. If pseudoaneurysms were detected on CT in group A, prophylactic embolization was performed. The frequency of delayed hemorrhage occurring more than 3 days after surgery in group A was compared with group B and with 212 patients (group C) who underwent partial nephrectomy between January 2010 and December 2011 without early postoperative CT. Changes in estimated glomerular filtration rate at discharge were compared among the groups. RESULTS: Prophylactic embolization of pseudoaneurysms was performed in 26 patients (8%) in group A. Frequency of delayed hemorrhage in group A (0.6%) was significantly lower than in groups B (4.6%; P = .038) and C (4.7%; P = .005). No major complications attributable to prophylactic embolization were observed. The decrease in estimated glomerular filtration rate in group A (-2% ± 13%) was smaller than that in group B (-8% ± 13%; P < .001) and not worse than that in group C (-4% ± 14%; P = .108). CONCLUSIONS: Prophylactic embolization of pseudoaneurysms detected on early postoperative CT can prevent delayed hemorrhage after partial nephrectomy, without major complications.

[Evaluation of the right internal iliac artery which is anastomosed to transplant renal artery using non-contrast enhanced MR angiography with electrocardiography-gated and 3D True SSFP time-spatial labeling inversion pulse sequence].

To evaluate whether electrocardiography-gated is useful in non-contrast-enhanced MRA with time-spatial labeling inversion pulse (Time-SLIP) in renal transplantation patients compared with respiration-triggered free-breathing. Simulation-based analyses of black blood time interval (BBTI) values for spatial selective inversion-recovery pulse and electrocardiography rates were performed, and confirmed on human subjects using a three-dimensional (3D) coherent steady-state free precession (SSFP) sequence on a 1.5 tesla Toshiba MRI scanner. Signal acquisition interval and BBTI values in which signal of a water tissue becomes the null point showed a strong correlation, and successfully suppressed signals from the background and provided better contrast between the arteries and the background. Because electrocardiography-gated non-contrast MRA does not depend on the respiration interval, providing a contrast stable, it was suggested to be an effective screening tool for evaluation of pelvic arteries.

Performance of gadoxetic acid-enhanced MRI for detecting hepatocellular carcinoma in recipients of living-related-liver-transplantation: comparison with dynamic multidetector row computed tomography and angiography-assisted computed tomography.

PURPOSE: To clarify the diagnostic performance of gadoxetic acid-enhanced MRI for the detection of hepatocellular carcinoma (HCC) in recipients of living related-liver transplantation (LRLT). MATERIALS AND METHODS: This retrospective study group consisted of 15 patients with 61 HCCs who each underwent multidetector row computed tomography (MDCT), gadoxetic acid-enhanced MRI, and angiography-assisted computed tomography (CT) before LRLT. The three modalities were compared for their ability to detect HCC. Two blinded readers independently reviewed the images obtained by each modality for the presence of HCC on a segment-by-segment basis using a 5-point confidence scale. The diagnostic performance of the modalities was evaluated in a receiver operating characteristic (ROC) analysis. The area under the ROC curve (Az), sensitivity, specificity, and accuracy were compared for the three modalities. RESULTS: No significant difference in Az, sensitivity, specificity, or accuracy was obtained among gadoxetic acid-enhanced MRI, MDCT, and angiography-assisted CT for both readers. For reader 1, the sensitivity (55.6%) and the accuracy (84.7%) of angiography-assisted CT were significantly higher than those of MDCT (33.3% and 78.0%) (P < 0.05). CONCLUSION: Gadoxetic acid-enhanced MRI has a relatively high diagnostic ability to detect HCC even in recipients of LRLT, equivalent to the abilities of MDCT and angiography-assisted CT.

Enhanced computed tomography after partial nephrectomy in early postoperative period to detect asymptomatic renal artery pseudoaneurysm.

OBJECTIVES: We systematically examined the incidence and potential implications of renal artery pseudoaneurysm occurring after partial nephrectomy detected by computed tomography screening in the early postoperative period. METHODS: Between January and December 2012, 117 patients underwent enhanced screening computed tomography on the fourth postoperative day after partial nephrectomy to evaluate for renal artery pseudoaneurysm. The size of the renal artery pseudoaneurysm and follow-up imaging were utilized to decide on pre-emptive angioembolization. Patient characteristics, tumor specifics and surgical data were analyzed. RESULTS: A total of 17 of 117 patients (15%) were found to have renal artery pseudoaneurysm on early postoperative computed tomography. Renal artery pseudoaneurysm occurred in nine of 73 open partial nephrectomy patients (12.3%) and eight of 44 laparoscopic partial nephrectomy patients (18.2%). One early patient experienced a postoperative bleed on postoperative day 9 after diagnosis of a 3.5-mm diameter renal artery pseudoaneurysm on postoperative day 3, and this patient was successfully managed with angioembolization. There were no other postoperative bleeding episodes. Rapid growth of a renal artery pseudoaneurysm was observed in a second patient who was treated with pre-emptive angioembolization. Five patients were diagnosed with small renal artery pseudoaneurysm (2-4 mm) on postoperative day 4 and observed with follow-up imaging showing resolution of the renal artery pseudoaneurysm. Another 10 patients were diagnosed with larger renal artery pseudoaneurysm (≥4 mm) and were managed with pre-emptive angioembolization. CONCLUSIONS: Early postoperative computed tomography screening is able to detect modest rates of asymptomatic renal artery pseudoaneurysm. The rate of postoperative bleed remained low with a policy of selective angioembolization. Renal artery pseudoaneurysm size and interval enlargement might indicate the risk of rupture. Further studies are required to assess the potential role of pre-emptive angioembolization.

Miliary tuberculosis diagnosed by diffuse hepatic uptake on PET/CT and transjugular liver biopsy.

The patient was an 81-year-old man. In his 20s, he had been treated with pharmacotherapy for pulmonary tuberculosis for 1 year. He presented to the Department of Respiratory Medicine with a chief complaint of dyspnea. The possibility of respiratory disease appeared to be low, but hepatic impairment was detected. The patient was thus referred to our department. Though the cause of hepatic impairment was unknown, the soluble interleukin-2 receptor level was elevated, suggesting malignant lymphoma. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) revealed diffuse, homogenous, intense FDG uptake in the entire liver, and transjugular liver biopsy confirmed the diagnosis. Histopathological examination revealed an epithelioid granuloma, and auramine staining was positive for bacilli suggestive of tuberculosis. CT revealed diffuse micronodular shadows in the lung, yielding a diagnosis of miliary tuberculosis. Therefore, the patient was prescribed antituberculosis medication by the Department of Respiratory Medicine. His subsequent clinical course was good. The miliary (hepatic) tuberculosis was typical based on the diffuse, homogenous, intense FDG uptake throughout the liver observed on PET-CT.

Antitumor effect of bevacizumab in a xenograft model of canine hemangiopericytoma.

Canine hemangiopericytoma (CHP) is characterized by frequent local recurrence and increased invasiveness. Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis in tumors. The aim of the present study was to investigate the effect of a single dose of bevacizumab on a xenograft model of CHP. VEGF protein was secreted from cultured CHP cells and interacted with bevacizumab. Bevacizumab treatment suppressed tumor growth by inhibiting tumor angiogenesis, whereas no significant differences were observed in the proliferation index and apoptosis rates of treated and untreated mice. Thus, bevacizumab had antitumor effects in a xenograft model of CHP.

Prediction of the Spontaneous Estrus Expression Period Based on Large (≥10 mm) Follicle Numbers in Lactating Holstein Dairy Cows.

The objectives of this study were (1) to investigate the distribution of large (≥10 mm) follicle numbers during the estrous cycle and (2) to compare the timing of the estrus expression period after the ovarian examination between cows with one large follicle (1F) and two or more large follicles (2F) with functional corpus luteum (CL) at the ovarian examination in lactating Holstein dairy cows. In experiment 1, we performed 393 ovarian examinations by ultrasonography, addressed the existence of CL (≥20 mm) and large follicle numbers, and classified cows into 1F (n = 229) and 2F (n = 164) groups. The 1F appearance rates were beyond 75% each day during 3 to 12 d after estrus. However, 2F appearance rates were beyond 75% each day during 15 to 24 d after estrus. In experiment 2, we performed 302 ovarian examinations by ultrasonography and classified cows into the 1F (n = 168) and 2F (n = 134) groups. Estrus detection was performed for 24 d after the ovarian examination in each cow. In the 2F group, 75% of estrus occurred within 9 d of the ovarian examination. However, 75% of estrus occurred 10 d after the ovarian examination in 1F. Days from the ovarian examination to estrus were significantly shorter in the 2F (6.0 d; median, 7.2 ± 4.0 d; mean ± SD) than in the 1F (13 d, 12.4 ± 4.3 d) group. In conclusion, focusing on ≥10 mm follicle numbers with CL could be useful for predicting the estrus expression period.

Oral pharmacokinetics of sulfadiazine and sulfamonomethoxine in female Holstein milking cows.

The efficacy of orally administered drugs in cattle is thought to be slow because of the anatomical and physiological features of their forestomach. Thus, parenteral routes are mainly preferred to administer drugs. However, the effect of some drugs with unique physicochemical properties was promptly obtained even after oral administration in clinically ill cattle. Therefore, the present study aimed to investigate pharmacokinetically the usefulness of the oral route in cattle by comparing the oral pharmacokinetic properties of two sulfonamides with different physicochemical properties. Sulfadiazine (SDZ) and sulfamonomethoxine (SMM) were administered by intravenous and oral route to four female Holstein cows with a 4-weeks washout period. Blood samples were collected over time, and SDZ and SMM concentrations in plasma were analyzed by HPLC. Data obtained from the same animal after intravenous and oral administration were simultaneously analyzed with the one compartment model, and kinetic parameters were calculated. The Tmax (mean ± SD) of SMM (2.75 ± 0.96 hr) was significantly achieved earlier than that of SDZ (5.00 ± 1.15 hr). Further, the mean absorption time of SMM (5.24 ± 0.69 hr) was significantly shorter than that of SDZ (5.92 ± 1.11 hr). Also, the half-life of absorption of SMM (3.91 ± 0.51 hr) was significantly shorter than that of SDZ (4.51 ± 0.82 hr). These data suggest that the absorption rates of highly unionized drugs (such as SMM) from the forestomach of cattle may be markedly higher than less unionized ones (such as SDZ).

Graft failure after allogeneic islet transplantation in a patient with type 1 diabetes and a high anti-glutamic acid decarboxylase antibody titer.

Pancreatic islet transplantation is a ß-cell replacement therapy for people with insulin-deficient diabetes who have difficulty in glycemic control and suffer from frequent severe hypoglycemia. However, the number of islet transplantations carried out is still limited in Asia. We report a case of allogeneic islet transplantation in a 45-year-old Japanese man with type 1 diabetes. Although the islet transplantation was successfully carried out, graft loss was observed on the 18th day. Immunosuppressants were used in accordance with the protocol, and donor-specific anti-human leukocyte antigen antibodies were not detected. Autoimmunity relapse was also not observed. However, the patient had a high titer of anti-glutamic acid decarboxylase antibody from before the islet transplantation, and autoimmunity might thus have affected the ß-cells in the transplanted islet. The evidence is still scarce to reach conclusions, and further data accumulation is required to enable proper patient selection before islet transplantation.

EP2 and EP4 receptors on muscularis resident macrophages mediate LPS-induced intestinal dysmotility via iNOS upregulation through cAMP/ERK signals.

Intestinal resident macrophages play an important role in gastrointestinal dysmotility by producing prostaglandins (PGs) and nitric oxide (NO) in inflammatory conditions. The causal correlation between PGs and NO in gastrointestinal inflammation has not been elucidated. In this study, we examined the possible role of PGE(2) in the LPS-inducible inducible NO synthase (iNOS) gene expression in murine distal ileal tissue and macrophages. Treatment of ileal tissue with LPS increased the iNOS and cyclooxygenase (COX)-2 gene expression, which lead to intestinal dysmotility. However, LPS did not induce the expression of iNOS and COX-2 in tissue from macrophage colony-stimulating factor-deficient op/op mice, indicating that these genes are expressed in intestinal resident macrophages. iNOS and COX-2 protein were also expressed in dextran-phagocytized macrophages in the muscle layer. CAY10404, a COX-2 inhibitor, diminished LPS-dependent iNOS gene upregulation in wild-type mouse ileal tissue and also in RAW264.7 macrophages, indicating that PGs upregulate iNOS gene expression. EP(2) and EP(4) agonists upregulated iNOS gene expression in ileal tissue and isolated resident macrophages. iNOS mRNA induction mediated by LPS was decreased in the ileum isolated from EP(2) or EP(4) knockout mice. In addition, LPS failed to decrease the motility of EP(2) and EP(4) knockout mice ileum. EP(2)- or EP(4)-mediated iNOS expression was attenuated by KT-5720, a PKA inhibitor and PD-98059, an ERK inhibitor. Forskolin or dibutyryl-cAMP mimics upregulation of iNOS gene expression in macrophages. In conclusion, COX-2-derived PGE(2) induces iNOS expression through cAMP/ERK pathways by activating EP(2) and EP(4) receptors in muscularis macrophages. NO produced in muscularis macrophages induces dysmotility during gastrointestinal inflammation.

First High power test results for 2.1 GHz superconducting photonic band gap accelerator cavities.

We report the results of the recent high power testing of superconducting radio frequency photonic band gap (PBG) accelerator cells. Tests of the two single-cell 2.1 GHz cavities were performed at both 4 and 2 K. An accelerating gradient of 15 MV/m and an unloaded quality factor Q(0) of 4×10(9) were achieved. It has been long realized that PBG structures have great potential in reducing long-range wakefields in accelerators. A PBG structure confines the fundamental TM(01)-like accelerating mode, but does not support higher order modes. Employing PBG cavities to filter out higher order modes in superconducting particle accelerators will allow suppression of dangerous beam instabilities caused by wakefields and thus operation at higher frequencies and significantly higher beam luminosities. This may lead towards a completely new generation of colliders for high energy physics and energy recovery linacs for the free-electron lasers.

MR prediction of liver fibrosis using a liver-specific contrast agent: Superparamagnetic iron oxide versus Gd-EOB-DTPA.

PURPOSE: To examine whether the uptake of a liver-specific contrast agent in the liver parenchyma was correlated with the degree of liver fibrosis. MATERIALS AND METHODS: This retrospective study included 54 and 63 patients who underwent superparamagnetic iron oxide (SPIO)- and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI before liver surgery, respectively. For each patient, we calculated ΔR2* and ΔR2, which represent differences in R2* and R2 values of the liver parenchyma before and after administration of SPIO; and the increase rate of liver-to-spleen signal intensity ratio (LSR) on the hepatobiliary phase compared with the precontrast image. The correlation of each MR parameter with the degree of liver fibrosis (F0 to F4) was assessed using Spearman's rank correlation test. RESULTS: The increase rate of LSR was best correlated with the degree of liver fibrosis and significantly decreased as the liver fibrosis progressed (rho = -0.641; P < 0.0001). It showed sensitivity of 76.9% and specificity of 83.3% in differentiating F3 or greater fibrosis when 1.126 or less was set up as a cut-off value. No significant correlation was obtained between ΔR2* or ΔR2 and the degree of liver fibrosis. CONCLUSION: The uptake of Gd-EOB-DTPA in the liver parenchyma decreased as the liver fibrosis progressed. J. Magn. Reson. Imaging 2012;36:664-671. © 2012 Wiley Periodicals, Inc.

Radiological catheter placement for transcatheter arterial steroid injection therapy to treat severe acute hepatic failure: technical feasibility and efficacy.

BACKGROUND: Severe acute hepatic failure (SAHF), which progresses to fulminant form in some cases, is a life-threatening disease. PURPOSE: To assess the technical feasibility and the efficacy of transcatheter arterial steroid injection therapy (TASIT) for SAHF. MATERIAL AND METHODS: Twenty-seven patients with SAHF, 10 of whom had variant anatomy of the hepatic artery, underwent radiologic placement of an indwelling catheter in the hepatic artery, and TASIT was subsequently performed for three days. The tips of the catheters were inserted as follows: common hepatic artery (n = 18), proper hepatic artery (n = 4), and replaced right hepatic artery (n = 5). The clinical success rate of TASIT and the prognosis after TASIT were evaluated. RESULTS: In one patient, intimal injury of the left hepatic artery was encountered; however, TASIT could be resumed and completed via intrahepatic arterial collaterals. In two patients, the catheter tip placement was corrected on the following day because of dislocation. Finally, TASIT could be carried out in all patients. Twenty-two patients (81.5%) responded to TASIT but five patients (18.5%) did not. Among the five non-responders, two patients were transferred to liver transplantation and survived, and three patients died. There was no significant difference in the response rates to TASIT among locations of catheter tip (P > 0.05) and extent of drug distribution in the liver (P > 0.05). CONCLUSION: TASIT is a feasible and efficient treatment option for SAHF regardless of the anatomic variation of the hepatic artery. Careful manipulation during the procedure to prevent injury of the hepatic artery may be the most essential factor not only for successful TASIT but also for liver transplantation, which may be performed on TASIT non-responders.