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Hyperperfusion injury is a rare but critical complication associated with revascularization for long-standing severe artery stenosis. Here we report a rare case of a patient with renal hyperperfusion injury after undergoing percutaneous transluminal renal angioplasty for renovascular hypertension as a sequela of neuroblastoma after radiation therapy. (Level of Difficulty: Advanced.), Central Illustration

A 61-year-old man presented with retroperitoneal hemorrhage caused by an aneurysm rupture of the pancreaticoduodenal arcade (PDA), and acute celiac artery dissection distal to celiac axis stenosis. Owing to the gradual growth of the false lumen, we planned to deploy a stent to the celiac artery dissection and embolize the PDA aneurysm. Prior to stent placement, we assessed the acute celiac artery dissection distal to the stenosis using four-dimensional computed tomography (CT) angiography through expiration/inspiration/expiration cycle. We diagnosed median arcuate ligament syndrome considering that the celiac axis showed a hooked narrowing at end-expiration, and the compression decreased at end-inspiration. Additionally, the true lumen distal to the stretched axis dilated in the inspiration phase. Therefore, we could advance a catheter into the true lumen during inspiration and successfully deploy a stent. Subsequently, laparoscopic median arcuate ligament release was performed after the stent deployment. A postoperative CT scan showed good patency in the stent, with disappearance of the blood filling the false lumen and with reduced celiac axis stenosis.

Background Budd–Chiari syndrome (BCS) is a rare vascular disorder of the liver, and acute and secondary BCS is even rarer. Case presentation A 62-year-old man with perihilar cholangiocarcinoma of Bismuth type IIIa underwent right hemi-hepatectomy with caudate lobectomy and pancreatoduodenectomy. Adjuvant chemoradiotherapy was performed due to a positive hepatic ductal margin. Subsequently, the disease passed without recurrence. The patient visited for acute onset abdominal pain at the 32nd postoperative month. Multidetector-row computed tomography (MDCT) showed stenosis of the left hepatic vein (LHV) root, which was the irradiated field, and thrombotic occlusion of the LHV. The patient was diagnosed with acute BCS caused by adjuvant radiotherapy. Although anticoagulation therapy was performed, the patient complained of sudden upper abdominal pain again. MDCT showed an enlarged LHV thrombus and hepatomegaly. The patient was diagnosed with exacerbated acute BCS, and stenting for the stenotic LHV root was performed with a bare stent. Although stenting for the LHV root was very effective, restenosis occurred twice due to thrombus in the existing stent, so re-stenting was performed twice. The subsequent clinical course was acceptable without recurrence or restenosis of the LHV root as of 6 months after the last stenting using a stent graft. Conclusion Although no case of BCS caused by radiotherapy has yet been reported, the present case showed that late side effect of radiotherapy can cause hepatic vein stenosis and secondary BCS.

The impact of clinical information on radiological diagnoses and subsequent clinical management has not been sufficiently investigated. This study aimed to compare diagnostic performance between radiological reports made with and without clinical information and to evaluate differences in the clinical management decisions based on each of these reports. We retrospectively reviewed 410 patients who presented with acute abdominal pain and underwent unenhanced (n = 248) or enhanced CT (n = 162). Clinical information including age, sex, current and past history, physical findings, and laboratory tests were collected. Six radiologists independently interpreted CTs that were randomly assigned with or without clinical information, made radiological diagnoses, and scored the diagnostic confidence level. Four general and emergency physicians simulated clinical management (i.e., followed up in the outpatient clinic, hospitalized for conservative therapy, or referred to other departments for invasive therapy) based on reports made with or without the clinical information. Reference standards for the radiological diagnoses and clinical management were defined by an independent expert panel. The radiological diagnoses made with clinical information were more accurate than those made without clinical information (93.7% vs. 87.8%, p = 0.008). Median interpretation time for radiological reporting with clinical information was significantly shorter than that without clinical information (median 122.0 vs. 139.0 s, p < 0.001). Clinical simulation better matched the reference standard for clinical management when radiological diagnoses were made with reference to clinical information (97.3% vs. 87.8%, p < 0.001). Access to adequate clinical information enables accurate radiological diagnoses and appropriate subsequent clinical management of patients with acute abdominal pain. • Radiological interpretation improved diagnostic accuracy and confidence level when clinical information was provided. • Providing clinical information did not extend the interpretation time required by radiologists. • Radiological interpretation with clinical information led to correct clinical management by physicians.

A 71-year-old man who received a total arch replacement with a knitted Dacron® graft presented aneurysmal sac re-expansion due to leakage at the distal anastomotic site of the graft. He did not tolerate the stress of general anesthesia due to severe pulmonary function impairment. Therefore, thoracic endovascular aortic repair (TEVAR) in zone 3 was performed under epidural anesthesia. Contrast-enhanced computed tomography (CT) revealed another leakage into the aneurysmal sac in zone 1 after performing TEVAR. Because open surgical repair and debranching TEVAR were contraindicated, transcatheter arterial embolization was performed with careful consideration of his comorbidities. Follow-up contrast-enhanced CT performed 2 weeks after embolization indicated no opacification of the aneurysmal sac, and noncontrast-enhanced CT a year after embolization showed no dilatation of the aneurysmal sac.

A 78-year-old man presented with lymphatic fluid collections in bilateral inguinal area after bilateral inguinal lymph node dissections. Because no inguinal or popliteal lymph nodes were observed under ultrasound examination, intranodal lymphangiography was not applicable. Although traditional pedal lymphangiography was required, it was difficult to perform this procedure owing to the decreasing frequency over the past 20 years and being unavailable in not only our institution, but also other in institutions. Therefore, we performed catheterization using the 29-guage Argyle PI catheter into the lymphatic duct in lower legs under a microscope and achieved successful percutaneous embolization using N-butyl cyanoacrylate for inguinal lymphatic leakage.

A 77-year-old man presented with an incidental finding of right renal artery aneurysm without symptoms. Computed tomography revealed a 22 mm saccular aneurysm with a wide neck at the main renal artery trunk. An 8 × 100 mm Viabahn stent graft (W. L. Gore, Flagstaff, AZ) was deployed by fully pulling back the guiding sheath. However, the deployment knob was not able to be pulled. We returned the guiding sheath to the original position and confirmed the cause was the bowstring phenomenon. Because avoidance of this phenomenon required straightening of the tortuous vessel, the stent graft was deployed by short pull-back of the guiding sheath. Computed tomography after a year revealed no opacification of the aneurysm and the patency of the stent graft.

Acute pulmonary thromboembolism occurring during cancer treatment has been increasing with the number of cancer patients and chemotherapy cases. Computed tomographic pulmonary angiography (CTPA) for evaluating the pulmonary artery is generally performed using rapid injection of contrast medium. However, intravenous catheters for contrast medium injection might cause extravasation due to rapid injection. This case series describes three patients who underwent contrast-enhanced computed tomography combined with low-tube-voltage imaging and slow injection. Low-tube-voltage slow-injection CTPA can be an effective technique for obtaining high contrast enhancement while accommodating fragile veins and low injection rates.

Objective Accurate assessment and localization of aldosterone-producing adenomas (APAs) are essential for the treatment of primary aldosteronism (PA). Although adrenal venous sampling (AVS) is the standard method of reference for subtype diagnosis in PA, controversy exists concerning the criteria for its interpretation. This study aims to determine better indicators that can reliably predict subtypes of PA. Method Retrospective, single-cohort analysis including 209 patients with PA who were subjected to AVS. Eighty-two patients whose plasma aldosterone concentrations (PAC) were normalized after surgery were histopathologically or genetically diagnosed with APA. The accuracy of image findings was compared to AVS results. Receiver operating characteristic (ROC) curve analysis between the operated and the no-apparent laterality groups was performed using AVS parameters and loading test for diagnosis of PA. Result Agreement between image findings and AVS results was 56.3%. ROC curve analysis revealed that the lateralization index (LI) after adrenocorticotropin stimulation cutoff was 2.40, with 98.8% sensitivity and 97.1% specificity. The contralateral suppression index (CSI) cutoff value was 1.19, with 98.0% sensitivity and 93.9% specificity. All patients over the LI and CSI cutoff values exhibited unilateral subtypes. Among the loading test, the best classification accuracy was achieved using the PAC reduction rate after a saline infusion test (SIT) >33.8%, which yielded 87.2% sensitivity or a PAC after a SIT Conclusion The combined criteria of the PAC reduction rate and PAC after the SIT can determine which subset of patients with APA who should be performed AVS for validation.

To assess the correlation value between adrenal venous sampling (AVS) and I-6β-iodomethyl-19-norcholesterol (NP-59) adrenal scintigraphy in differentiating aldosterone-producing adenoma (APA) from bilateral idiopathic hyperaldosteronism (BHA), and the use of NP-59 scintigraphy as an alternative to AVS.Overall, 29 patients with APA or BHA who underwent AVS and dexamethasone-suppression NP-59 scintigraphy were included between 2010 and 2017. The correlation value between AVS and dexamethasone-suppression NP-59 scintigraphy was assessed using each lateralisation index (LIAVS and LI1NP-59). Tumour presence and size were evaluated using computed tomography. The sensitivity and specificity of dexamethasone-suppression NP-59 scintigraphy for APA according to each lateralisation index threshold were calculated.Of 29 patients, 12 presented with APA and 17 with BHA according to AVS. The correlation value between LIAVS and LI1NP-59 was 0.63 (P0.001). If the cut-off points were 2.55 and 1.80 in all cases, the sensitivity and specificity were 0.33 and 1.00 as well as 0.58 and 0.94, respectively. In adrenal microtumours (maximum diameter ≤10 mm), no cases revealed a cut-off point of1.8. However, in adrenal macrotumours (maximum diameter10 mm), the cut-off point of 2.55 represented the best compromise (sensitivity: 0.44; specificity: 1.00).NP-59 scintigraphy can be used as an alternative to AVS if there is a strong lateralisation on NP-59 scintigraphy and adrenal macrotumours observed on the computed tomography when AVS is technically challenging, particularly in the right adrenal vein cannulation, and if contraindications, such as allergy to contrast materials and renal failure, are observed.

To evaluate the relationship between gelatin sponge preparation methods and the incidence of intrauterine synechia following uterine artery embolization (UAE) for postpartum hemorrhage (PPH). In a retrospective monocentric study, we used data from 20 consecutive UAE procedures (19 patients) for PPH, performed in 2007–2016, in which gelatin sponge had been used. The gelatin sponge was processed either into a slurry by pumping it back and forth about 10 times through two syringes connected to a three-way stopcock or into pledgets using a scalpel and small scissors to obtain pieces approximately 2 × 2 × 2 mm in size. Patient information was obtained from medical records, and the data were compared between patients treated with the slurry (n = 7) or pledgets (n = 13) forms. Due to the lack of follow-up data and hysterectomy after UAE, the sample size was 6 and 12 because 1 patient with 2 procedures was excluded. The rate of intrauterine synechia was significantly higher in the slurry group (5/6, 83.3%) than that in the pledgets group (0/12, 0%; P

// Koji Takahashi 1 , Toshio Tsuyuguchi 1 , Atsushi Saiga 2 , Takuro Horikoshi 2 , Yoshihiko Ooka 1 , Harutoshi Sugiyama 1 , Masato Nakamura 1 , Junichiro Kumagai 1 , Mutsumi Yamato 1 , Yotaro Iino 1 , Ayako Shingyoji 1 , Hiroshi Ohyama 1 , Shin Yasui 1 , Rintaro Mikata 1 , Yuji Sakai 1 and Naoya Kato 1 1 Department of Gastroenterology, Graduate School of Medicine, Chiba University, Chiba, Japan 2 Department of Radiology, Graduate School of Medicine, Chiba University, Chiba, Japan Correspondence to: Koji Takahashi, email: koji517@gmail.com Keywords: cholangiopancreatography; drainage; endoscopic retrograde; risk factor; stent Received: April 21, 2018 Accepted: May 24, 2018 Published: June 15, 2018 ABSTRACT Aim: In this study, we assessed the factors contributing to ineffective drainage in the initial transpapillary uncovered self-expandable metal stent (USEMS) placements in patients with unresectable malignant hilar biliary strictures (UMHBSs) (Bismuth type II or higher). Methods: This was a retrospective, single-center study. A total of 97 patients with UMHBSs who underwent technically successful initial USEMS placements using endoscopic retrograde cholangiopancreatography (ERCP) were classified into the effective drainage group (n = 73) or the ineffective drainage group (n = 24). We then compared group characteristics, clinical outcomes, and drained liver volumes. Drained liver volume was measured by using computed tomography volumetry. The definition of effective biliary drainage was a 50% decrease in the serum total bilirubin level or normalization of the level within 14 days of stent placement. Results: Univariate analysis showed that ineffective drainage was associated with the pre-ERCP serum total bilirubin level ( P = 0.0075), pre-ERCP serum albumin level ( P = 0.042), comorbid liver cirrhosis ( P = 0.010), drained liver volume ( P = 0.0010), and single stenting ( P = 0.022). Multivariate analysis identified comorbid liver cirrhosis (adjusted odds ratio [OR], 5.79; 95% confidence interval [CI], 1.30–25.85; P = 0.022) and drained liver volume < 50% (adjusted OR, 5.50; 95% CI, 1.50–20.25; P = 0.010) as independent risk factors of ineffective drainage. Conclusion: Comorbid liver cirrhosis and a drained liver volume < 50% contributed significantly to ineffective drainage in the initial transpapillary USEMS placements for UMHBSs.

An asymptomatic 48-year-old man presented with multiple aneurysms in a primary racemose hemangioma of the right bronchial artery. Bronchial arteriography revealed a tortuous artery with four fusiform aneurysms of varying sizes and aneurysmal dilatation with marked thrombus formation in the long segment of the distal portion. Because the tip of catheter could not pass beyond the aneurysmal dilatation, we performed balloon-occluded embolization using a mixture of N-butyl-2-cyanoacrylate (NBCA) and iodized oil. For four other aneurysms, we performed embolization using a coil alone or with NBCA. After 6 months, right bronchial arteriography revealed no enhancement of the aneurysms. Despite the rarity of this procedure, embolization with NBCA is a good option for bronchial artery aneurysm embolization.

After the occurrence of the 2011 magnitude 9 Tohoku earthquake, the seismicity in the overriding plate changed. The seismicity appears to form distinct belts. From the spatiotemporal distribution of hypocenters, we can quantify the evolution of seismicity after the 2011 Tohoku earthquake. In some earthquake swarms near Sendai (Nagamachi-Rifu fault), Moriyoshi-zan volcano, Senya fault, and the Yamagata–Fukushima border (Aizu-Kitakata area, west of Azuma volcano), we can observe temporal expansion of the focal area. This temporal expansion is attributed to fluid diffusion. Observed diffusivity would correspond to the permeability of about 10−15 (m2). We can detect the area from which fluid migrates as a seismic low-velocity area. In the lower crust, we found seismic low-velocity areas, which appear to be elongated along N–S or NE–SW, the strike of the island arc. These seismic low-velocity areas are located not only beneath the volcanic front but also beneath the fore-arc region. Seismic activity in the upper crust tends to be high above these low-velocity areas in the lower crust. Most of the shallow earthquakes after the 2011 Tohoku earthquake are located above the seismic low-velocity areas. We thus suggest fluid pressure changes are responsible for the belts of seismicity.

[1] Anisotropy is an important feature of elastic wave propagation in the Earth and can arise from a variety of ordered architectures such as fractures with preferential alignments or preferred crystal orientations. We studied the regional variations in shear wave anisotropy around a deep Low-Frequency Earthquake (LFE) zone beneath the Kii Peninsula, SW Japan, using waveforms of local earthquakes observed by a dense linear array along the LFE zone. The fast directions of polarization are subparallel to the strike of the margin for both crustal and intraslab earthquakes. The delay time of the split shear waves in intraslab earthquakes is larger than that in crustal earthquakes and shows a down-dip variation across the LFE zone. This indicates that anisotropy exists in the mantle wedge and in the lower crust and/or oceanic slab. We explain the observed delay time of 0.015–0.045 s by suggesting that the mantle wedge consists of a deformed, 1–15 km thick serpentine layer if the mantle wedge is completely serpentinized. In addition to high-fluid pressures within the oceanic crust, the sheared serpentine layer may be a key factor driving LFEs in subduction zones.

[1] Intense swarm-like seismicity associated with shallow normal faulting was induced in Ibaraki and Fukushima prefectures, Japan, following the 2011 Tohoku-Oki earthquake. This seismicity shows a systematic spatiotemporal evolution, but little is known of the heterogeneity in crustal structure in this region, or its influence on the evolution of the seismicity. Here, we elucidate a high-resolution model of crustal structure in this region and determine precise hypocenter locations. Hypocenters in Ibaraki Prefecture reveal a planar earthquake alignment dipping SW at ~45°, whereas those in Fukushima Prefecture show a more complex distribution, consisting of conjugate sets of aligned small earthquakes. On the north of the hypocenter of the largest earthquake in the sequence (the M7.0 Iwaki earthquake), we imaged a high-velocity body at shallow depths that lacks aftershock seismicity. Based on fault source models, the large-slip region of the Iwaki earthquake is situated along a zone that roughly coincides with this high-velocity body. We delineated a separate low-velocity anomaly directly beneath the hypocenter of the Iwaki earthquake, indicating crustal fluids in this region. We hypothesize that strong crust underwent structural failure due to the infiltration of crustal fluids into the seismogenic zone from deeper levels, causing the Iwaki earthquake.

We present high-resolution three-dimensional tomographic images of the crust beneath the entire Kyushu arc, and particularly the western portion. Our results reveal a velocity anomaly that correlates well with an upper crustal gravity anomaly. Significant low-velocity anomalies exist beneath the Miyazaki plane and along the Beppu-Shimabara Graben. Another extensive low-velocity region near the bottom of the crust is located just below the volcanic front and between active volcanoes. The low-velocity anomalies exhibit low V p and V p /V s characteristics, and the spatial relationship between these anomalies, the Bouguer gravity anomaly, and the Moho suggests that low-density material at the base of the crust is responsible for both the seismic and gravity signatures. We interpret this material to constitute a relict ridge subducting below the Kyushu Mountains.

We report the results of continuous monitoring—using a seismometer array—of the travel time of seismic waves generated by an ACROSS artificial seismic source. The seismometer array, which was deployed in a surface vault located 2.4 km from the source, recorded both directP- andS-waves and refractedP- andS-waves that traveled along a velocity boundary between the granite basement and overlying sedimentary rocks. We analyzed temporal variation in differential travel time and apparent velocity for these phases for a period of 1 month and found significant temporal variation in the differential travel time. Most of the variation can be attributed to changes in environmental conditions, such as atmospheric temperature and rainfall. Variation is even observed in the seismogram that is located 50 m from the vibration source, although much smaller variation is observed in the vibration of the foundation to which the source is attached. The spectral study revealed that the effects of temperature and rainfall depend strongly on the frequency range used by ACROSS and that a large variation occurs in the 15- to 20-Hz range, especially between 17 and 20 Hz. The environmental effect on the temporal variation is comparable to the record of refractedSwaves and that of a distance of 50 m, whereas a larger variation was observed in the directSwave. This result shows that the signal is affected by the environmental change near the vibration source. The environmental effect can be drastically reduced when the signal from the 15- to 20-Hz range is eliminated in the analysis.

SUMMARY Spatial and temporal variations in seismic anisotropy in the crust are investigated using earthquakes in the crust and the subducting Philippine Sea Plate beneath the Tokai region, central Japan. We use a total of 351 high-quality waveform data recorded from 1986 December until 1999 August by the microearthquake observation network of the Research Center for Seismology and Volcanology, Nagoya University. The leading shear waves are polarized in an approximately E–W direction, independent of the focal depth, showing consistency with the direction of regional horizontal maximum compressive stress in the Tokai region. The time delay increases for greater focal depth down to 30 km. These results indicate that the regional compressive stress controls anisotropy not only in the upper crust but also in the lower crust. Assuming a uniform distribution of anisotropy, the degree of anisotropy is estimated to be 0.6 per cent in the lower crust. An increase in time delay is found after the Aichi-ken Tobu earthquake (M= 5.7) in 1997 at station STN. This variation is statistically significant and is not an apparent change due to the variation in hypocentre distribution or any kind of artificial effect. On the other hand, no temporal variation in time delay is found at station INU. The spatial pattern of the temporal variation in time delay is consistent with the change in the Coulomb failure function (ΔCFF) caused by both coseismic and post-seismic fault slips. We therefore conclude that the observed temporal change in time delays might be caused by increasing crack density as well as pore fluid pressure due to the static stress change accompanied with the Aichi-ken Tobu earthquake.

To understand the mechanism of an intensive non-volcanic seismic swarm in the Kii Peninsula, Japan, we used a dense seismic linear array to measure fine-scale variations of seismic velocities and converted teleseismic waves. A low-velocity anomaly confined to just beneath the seismic swarm area is clearly imaged, which correlates spatially with an uplifted surface area and a highly conductive and strong attenuative body. These results suggest that fluids such as partial melt or water are present beneath this non-volcanic seismic swarm area. It is notable that the island arc Moho below the seismic swarm area is at a depth of approximately 32 km in the northern part of the seismic swarm area and shallows to approximately 20 km towards the south, due to the raised structure of the serpentinized mantle wedge. In addition, we show that the hydrated oceanic crust of the subducting Philippine Sea slab is characterized by low velocities with a high Poisson's ratio at depths of less than 40 km. In contrast, dehydration conversion from oceanic basalt to eclogite takes place at depths greater than 50 km. Water released from the subducting oceanic crust could cause serpentinization of the mantle wedge and infiltration into the forearc base of the overlying plate. The interaction between dehydration of the subducting oceanic crust and hydration of the mantle wedge and overlying plate exerts an important role in driving the non-volcanic seismic swarm activity in the Kii Peninsula.

[1] We have elucidated depth variations in the stress field associated with the 2007 Noto Hanto, Japan, earthquake by stress tensor inversion using high-quality aftershock data obtained by a dense seismic network. Aftershocks that occurred above 4 km in depth indicated a strike-slip stress regime. By contrast, aftershocks in deeper parts indicated a thrust faulting stress regime. This depth variation in the stress regime correlates well with that in the slip direction derived from a finite source model using geodetic data. Furthermore, the maximum principal stress (σ1) axis was stably oriented approximately W20°N down to the depth of the mainshock hypocenter, largely in agreement with the regional stress field, but, below that depth, the σ1 axis had no definite orientation, indicating horizontally isotropic stress. One likely cause of these drastic changes in the stress regime with depth is the buoyant force of a fluid reservoir localized beneath the seismogenic zone.

金沢大学大学院自然科学研究科自然計測応用センター, 金沢大学理学部, A continuous observation of shear wave splitting for 17 years reveals a unique temporal variation in seismic anisotropy in the shallow crust induced by a larger earthquake (MW5.7) beneath the Tokai region, Japan. The delay time between the fast and slow wavelets coseismically increased and then decreased back to the pre-event value. The duration of the decreasing stage is about two years. The decrease may indicate crack healing in the upper 10 km of the crust. We approximate the temporal variation in the delay time as a function of logarithm of time, which is concordant with healing phenomena of cracks reported by laboratory experiments. The observation indicates that healing of cracks in crustal rocks is complete in approximately two years. Copyright 2005 by the American Geophysical Union.