Temporal variation in scattering and intrinsic attenuation due to earthquakes in East Asia.

Separated attenuation values have not been used in post-seismic variation research, although the scattering attenuation (Qs-1) parameter that can be used to estimate crustal inhomogeneity due to cracks. In this study, three earthquakes that occurred in Kumamoto (M7.3), Tottori (M6.6), and Gyeongju (M5.8) in 2016 were investigated by applying a multiple lapse time window analysis to seismograms recorded before and after the events. At a low frequency, significantly greater variation of the Qs-1 value was observed than the intrinsic attenuation (Qi-1) for the Kumamoto earthquake, whereas similarly large variation was observed for the Gyeongju earthquake. For the surrounding Kumamoto earthquake area of increased attenuation, even higher decreases in Qs-1 and Qi-1 were also observed. The increases occurred within a two year-period after mainshock. The large increases in attenuation, corresponding to regions with high peak ground acceleration, were limited to the basin area with an elevation below 500 m. Furthermore, post-seismic increases in attenuation values were found to correlate with the magnitude and length of the quiet periods of the earthquakes. From this study, Qs-1 and Qi-1 were shown as new parameters that can quantitatively measure the post-seismic deformation due to crustal earthquake.

Extraosseous Ewing sarcoma of the thyroid gland.

Ewing sarcoma of the bone is a highly malignant round-cell tumor that typically presents between 10 to 20 years of age and is more common in boys. It can have an extraosseous origin, although it is rare. We report a case of extraosseous Ewing sarcoma in the thyroid gland in a 9-year-old girl.

Tracking of neural stem cells in rats with intracerebral hemorrhage by the use of 3T MRI.

OBJECTIVE: To access the feasibility of clinically available 3T MRI to detect the migration of labeled neural stem cells (NSCs) in intracerebral hemorrhage (ICH) in a rat model. MATERIALS AND METHODS: The ethics committee of our institution approved this study. ICH was induced by the injection of collagenase type IV into the right striatum of ten Sprague-Dawley rats. Human NSCs conjugated with Feridex (super-paramagnetic iron oxide: SPIO) were transplanted into the left striatum one week after ICH induction. MRI was performed on a 3T scanner during the first, second, third, fourth, and sixth weeks post-transplantation. MRI was obtained using coronal T2- and T2*-weighted sequences. Two rats were sacrificed every week after in vivo MRI in order to analyze the histological findings. RESULTS: ICH in the right striatum was detected by MRI one and two weeks after transplantation without migration of the NSCs. There was no migration of the NSCs as seen on the histological findings one week after transplantation. The histological findings two weeks after transplantation showed a small number of NSCs along the corpus callosum. On MRI three weeks after transplantation, there was a hypointense line along the corpus callosum and decreased signal intensity in the right periventricular region. Histological findings three weeks after transplantation confirmed the presence of the hypointense line representing SPIO-labeled NSCs. MRI four and six weeks after transplantation showed a hypointense spot in the right periventricular region. The histological findings four and six weeks after transplantation showed the presence of prominent NSCs in the right periventricular region. CONCLUSION: 3T MRI can detect the migration of NSCs in rats with ICH along the corpus callosum. Therefore, 3T MRI could be feasible for detecting the migration of NSCs in the clinical setting of stem cell therapy.

Assessment of cerebrocortical areas associated with sexual arousal in depressive women using functional MR imaging.

INTRODUCTION: Mental illness is closely related with sexual dysfunction. A number of investigators have reported that depressive women have difficulties in sexual arousal. AIM: The purpose of this study was to compare the cerebrocortical regions associated with sexual arousal between the healthy and depressive women using functional magnetic resonance imaging (fMRI) based on the blood-oxygenation-level-dependent (BOLD) technique. METHODS: Together with nine healthy women (mean age: 40.3), seven depressive women (mean age: 41.7 years, mean Beck Depression Inventory: 35.6, mean Hamilton Rating Scale Depression-17: 34.9) underwent fMRI examinations using a 1.5T MR scanner (Signa Horizon; GE Medical Systems, Milwaukee, WI, USA). The fMRI data were obtained from seven oblique planes using gradient-echo EPI. Sexual stimulation paradigm began with a 1-minute rest and then 4-minute stimulation using an erotic video film. The brain activation maps and their resulting quantification were analyzed by the statistical parametric mapping (SPM99) program. The number of pixels activated by each task was used as brain activity, where the significance of the differences was evaluated by using independent t-test. MAIN OUTCOME MEASURES: We measured brain activation areas using BOLD-based fMRI with visual sexual stimulation in healthy volunteers and depressive patients. RESULTS: Healthy women were significantly (P < 0.05) activated in the regions of middle occipital gyrus, middle temporal gyrus, inferior frontal gyrus, insula, hypothalamus, septal area, anterior cingulate gyrus, parahippocampal gyrus, thalamus, and amygdala by erotic visual stimulation. In comparison with the healthy women, the depressive women gave lower activity, especially in the brain regions of hypothalamus (55.5:3.0), septal area (49.6:8.6), anterior cingulate gyrus (23.5:11.0), and parahippocampal gyrus (18.2:5.8). CONCLUSIONS: This preliminary study performed by fMRI gives valuable information on differentiation of the activated cerebral regions associated with visually evoked sexual arousal between healthy and depressive women. In addition, these findings might be useful to understand neural mechanisms for female sexual dysfunction in depressive women.

Brain activation areas of sexual arousal with olfactory stimulation in men: a preliminary study using functional MRI.

INTRODUCTION: There have been extensive studies evaluating the functional neuroanatomy of the brain during visual sexual stimulation. However, little data exist concerning the role of olfactory stimulation in human sexuality. AIM: This preliminary study intended to elucidate the brain areas responding to an olfactory sexual stimulus using functional magnetic resonance imaging (fMRI). METHODS: Eight healthy right-handed heterosexual male volunteers (20-35 years of age), having normal olfaction and no brain diseases, were recruited. During fMRI, a women's perfume was given as an olfactory sexual stimulant in an alternating block design with a 30-second stimulation period followed by a 30-second rest. After the fMRI sessions, the participants provided ratings for both the odorant's intensity and perceived arousal. MAIN OUTCOME MEASURES: The study subjects rated the odorant stimulation and perceived sexual arousal response by Likert-type rating scales. Brain activation maps were made by blood oxygenation level-dependent (BOLD)-based fMRI with an echo-planar imaging pulse sequence. RESULTS: Two out of eight subjects experienced "strong" sexual arousal, and three subjects experienced "moderate" arousal during olfactory stimulation, resulting in a mean score of 2.25 on a 4-point scale. The common brain areas activated in response to the odor stimulus in all eight subjects included the insula, the inferior and middle frontal gyrus, and the hypothalamus. The median cingulate gyrus, thalamus, angular gyrus, lingual gyrus, and cerebellar cortex were activated in subjects who had moderate or strong sexual arousal response. CONCLUSION: Olfactory stimulation with women's perfume produces the activation of specific brain areas in men. The brain areas activated differed according to the degree of perceived sexual arousal response. Further studies are needed to elucidate brain activation response according to the different kinds and intensities of olfactory stimulation.

Enhanced detectability of recurrent brain tumor using glucose-loading F-18 FDG PET.

A 43-year-old man with a history of lung cancer, brain metastasis, and gamma knife radiosurgery underwent FDG PET/CT to differentiate recurrence from radiation necrosis. Basal PET/CT scan showed equivocal uptake in the margin of necrotic tumor. After glucose loading (10% glucose 50 mL for 5 minutes), marginal FDG uptake was more easily depicted. Proton magnetic resonance spectroscopy (1H-MRS) showed increased Cho/Cr ratio (1.7), which was consistent with tumor recurrence. The patient underwent whole brain radiotherapy thereafter. It is implicated that hyperglycemia-induced reduction of glucose uptake in recurrent brain tumors was less than in a normal brain, resulting in higher tumor-to-gray matter ratio.

Preoperative staging of colorectal cancer: CT vs. integrated FDG PET/CT.

Accurate preoperative staging is essential in determining the optimal therapeutic planning for individual patients. The computed tomography (CT) in the preoperative staging of colorectal cancer, even if controversial, may be useful for planning surgery and/or neoadjuvant therapy, particularly when local tumor extension into adjacent organs or distant metastases are detected. There have been significant changes in the CT technology with the advent of multi-detector row CT (MDCT) scanner. Advances in CT technology have raised interest in the potential role of CT for detection and staging of colorectal cancer. In recent studies, MDCT with MPR images has shown promising accuracy in the evaluation of local extent and nodal involvement of colorectal cancer. Combined PET/CT images have significant advantages over either alone because it provides both functional and anatomical data. Therefore, it is natural to expect that PET/CT would improve the accuracy of preoperative staging of colorectal cancer. The most significant additional information provided by PET/CT relates to the accurate detection of distant metastases. For the evaluation of patients with colorectal cancer, CT has relative advantages over PET/CT in regard to the depth of tumor invasion through the wall, extramural extension, and regional lymph node metastases. PET/CT should be performed on selected patients with suggestive but inconclusive metastatic lesions with CT. In addition, PET/CT with dedicated CT protocols, such as contrast-enhanced PET/CT and PET/CT colonography, may replace the diagnostic CT for the preoperative staging of colorectal cancer.

The sentinel clot sign: a useful CT finding for the evaluation of intraperitoneal bladder rupture following blunt trauma.

OBJECTIVE: To evaluate the frequency and relevance of the "sentinel clot" sign on CT for patients with traumatic intraperitoneal bladder rupture in a retrospective study. MATERIALS AND METHODS: During a recent 42-month period, 74 consecutive trauma patients (45 men, 29 women; age range, 12-84 years; mean age, 50.8 years) with gross hematuria were examined by the use of intravenous contrast-enhanced CT of the abdomen and pelvis, followed by retrograde cystography. Contrast-enhanced CT scanning was performed by using a helical CT scanner. CT images were retrospectively reviewed in consensus by two radiologists. The CT findings including the sentinel clot sign, pelvic fracture, traumatic injury to other abdominal viscera, and the degree of intraperitoneal free fluid were assessed and statistically analyzed using the two-tailed x(2) test. RESULTS: Twenty of the 74 patients had intraperitoneal bladder rupture. The sentinel clot sign was seen for 16 patients (80%) with intraperitoneal bladder rupture and for four patients (7%) without intraperitoneal bladder rupture (p < 0.001). Pelvic fracture was noted in five patients (25%) with intraperitoneal bladder rupture and in 39 patients (72%) without intraperitoneal bladder rupture (p < 0.001). Intraperitoneal free fluid was found in all patients (100%) with intraperitoneal bladder rupture, irrespective of an associated intraabdominal visceral injury, whereas 19 (35%) of the 54 patients without intraperitoneal bladder rupture had intraperitoneal free fluid (p < 0.001). CONCLUSION: Detection and localization of the sentinel clot sign abutting on the bladder dome may improve the accuracy of CT in the diagnosis of traumatic intraperitoneal bladder rupture, especially when the patients present with gross hematuria.

Contralateral migration of cerebral sparganosis through the splenium.

Even though it has been known for some time that the cerebral sparganosis could migrate to the contralateral hemisphere, there have been no reports which described the route of migration. This paper reports a case of cerebral sparganosis which migrated from the right temporo-occipital lobe to the contralateral temporo-occipital lobe though the splenium over a period of 3 years. A 24-year-old man visited our hospital complaining of headache for about a month. Three years ago, non-contrast MRI had been performed in a local hospital, and the major finding was cortical atrophy and ventricular dilatation in the right temporo-occipital lobe area, which were compatible with cerebral sparganosis. After admission to our hospital, we performed MRI which showed a 2 cm-sized well-enhanced mass in the left temporo-occipital area. The findings of the right side were similar to the MRI checked 3 years ago. The presence of multiple calcifications and small enhanced lesions on the right side also indicated that the old lesion had been a cerebral sparganosis. The most important finding was that the FLAIR image showed that the entire splenium had high signal intensity which linked the high signal areas of both hemispheres. The patient underwent surgery with the guidance of neuronavigation. The mass was well-capsulated, and removed totally in an en bloc fashion. After opening the capsule, we found a long worm which showed the shape of a whole lava but no movement. The histopathological diagnosis was sparganosis.

Solitary small hepatic angiosarcoma: initial and follow-up imaging findings.

We report an uncommon case of solitary, small hepatic angiosarcoma that was initially considered as a hemangioma. We present the imaging findings, with an emphasis on the initial and follow-up CT and MR findings, as well as report on the more suggestive findings of angiosarcoma than those of a hemangioma.

CNS involvement in hemophagocytic lymphohistiocytosis: CT and MR findings.

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder that is characterized by proliferation of benign histiocytes, and this commonly involves the liver, spleen, lymph nodes, bone marrow and central nervous system (CNS). We report here on the CT and MR imaging findings in a case of CNS HLH that showed multiple ring enhancing masses mimicking abscess or another mass on the CT and MR imaging.

FDG PET/CT for the detection and evaluation of breast diseases: usefulness and limitations.

Positron emission tomography (PET) with fluorine 18 fluorodeoxyglucose (FDG) is used to diagnose, stage, and monitor breast cancer. FDG PET has the capability to depict abnormal metabolic activity before any anatomic change occurs; however, in the absence of identifiable anatomic structures on PET images, it may be impossible to identify the location of areas of increased radionuclide uptake. In such cases, the coregistration of PET images with images from computed tomography (CT) may help improve diagnostic accuracy and lead to better clinical management of patients with breast cancer. Although FDG PET/CT may have limited diagnostic value for detecting small primary breast tumors, well-differentiated breast cancer, or regional lymph node involvement, it is superior to conventional imaging modalities for detecting distant metastases and recurrences and for monitoring the response to therapy.

Moyamoya syndrome in a child with trisomy 12p syndrome.

A female, 2 years and 7 months of age, was admitted to the hospital with stupor and nystagmus following projectile vomiting. She had been prenatally diagnosed with trisomy 12p with a familial pericentric inversion of chromosome 12 originating from her mother. She manifested developmental delay and some dysmorphic features of the face and limbs compatible with the clinical features of trisomy 12p. Four-vessel cerebral angiography revealed severe stenosis and occlusion of the supraclinoid portion of the right and left internal carotid arteries with numerous collateral vessels in the vicinity of the occlusion. These features are consistent with moyamoya syndrome. This report presents the first case of moyamoya syndrome with trisomy 12p with a familial pericentric inversion of chromosome 12.

MR imaging findings of clonorchiasis.

OBJECTIVE: The purpose of this study was to evaluate the MR spectrum and MR cholangiographic imaging findings of clonorchiasis. MATERIALS AND METHODS: We reviewed 26 patients with confirmed clonorchiasis by either stool tests (n=24) or surgery (n=2). MR imaging was performed on a 1.5 T system (GE Medical Systems, Milwaukee, WI) with a torso coil. Axial T1- and T2-weighted, gadolinium-enhanced dynamic images and MR cholangiography were obtained. Image analyses were used to identify abnormalities of the intrahepatic and extrahepatic bile ducts and the presence of hepatobiliary malignancy. All MR examinations were reviewed by the consensus of two abdominal radiologists. RESULTS: Intrahepatic bile duct abnormalities were seen in 23 (89%) of the 26 patients. The most common finding was mild dilatation of the intrahepatic bile duct which was found in 21 (81%). "Too many intrahepatic ducts" were found in 16(62%), wall enhancement and thickening in 21 (81%) and filling defects and ductal stricture in the intrahepatic bile duct in 6 (24%) and 3 (12%) patients, respectively. Extrahepatic ductal dilation was found in 5 (19%) and 9 (35%) revealed hepatobiliary malignancy. CONCLUSION: MR imaging revealed various findings of clonorchiasis, including dilatation, wall enhancement, stricture of the intrahepatic ducts and filling defect within the intrahepatic bile duct.

Uterine cervical carcinoma after therapy: CT and MR imaging findings.

Cervical carcinoma is one of the most frequent causes of death in women. Computed tomography (CT) and magnetic resonance (MR) imaging are the primary modalities for follow-up of treated cervical carcinoma. A normal vaginal cuff after hysterectomy appears as a smooth, low-signal-intensity muscular wall on T2-weighted MR images. Early (2-3 months after treatment) and significant decreases in the signal intensity and volume of the tumor at MR imaging indicate a good response to radiation therapy. Sites of recurrence are the pelvis, lymph nodes, and distant sites. Pelvic recurrence appears as a heterogeneously enhancing mass at contrast material-enhanced CT and often appears as a heterogeneous, high-signal-intensity mass at T2-weighted MR imaging. Lymph node recurrence ranges from scattered, minimally enlarged nodes to large, conglomerate nodal masses. Determination of neoplastic infiltration of lymph nodes is based on size; most researchers consider nodes greater than 1 cm in short-axis diameter to be metastatic. Distant metastases are usually due to recurrent disease and occur in the abdomen, thorax, and bone. Knowledge of the normal therapeutic changes and the spectrum of recurrent tumor in patients with cervical carcinoma is important for accurate interpretation of follow-up CT and MR images.

Bronchial and nonbronchial systemic artery embolization for life-threatening hemoptysis: a comprehensive review.

Massive hemoptysis is one of the most dreaded of all respiratory emergencies and can have a variety of underlying causes. In 90% of cases, the source of massive hemoptysis is the bronchial circulation. Diagnostic studies for massive hemoptysis include radiography, bronchoscopy, and computed tomography (CT) of the chest. Bronchoscopy and chest radiography have been considered the primary methods for the diagnosis and localization of hemoptysis. Many researchers currently suggest that CT should be performed prior to bronchoscopy in all cases of massive hemoptysis. Bronchial artery embolization (BAE) is a safe and effective nonsurgical treatment for patients with massive hemoptysis. However, nonbronchial systemic arteries can be a significant source of massive hemoptysis and a cause of recurrence after successful BAE. Knowledge of the bronchial artery anatomy, together with an understanding of the pathophysiologic features of massive hemoptysis, are essential for planning and performing BAE in affected patients. In addition, interventional radiologists should be familiar with the techniques, results, and possible complications of BAE and with the characteristics of the various embolic agents used in the procedure.

Three-dimensional multi-detector row CT portal venography in the evaluation of portosystemic collateral vessels in liver cirrhosis.

Multi-detector row computed tomography (CT) offers distinct advantages over traditional spiral CT. Multi-detector row CT scanners are faster and allow thinner collimation than single-detector row spiral CT scanners. The use of multi-detector row CT combined with postprocessing of the imaging data with a variety of three-dimensional reformatting techniques (eg, maximum intensity projection, shaded surface display, volume rendering) allows creation of vascular maps whose quality equals or exceeds that of maps created at classic angiography for many applications. Three-dimensional multi-detector row CT portal venography can help determine the extent and location of portosystemic collateral vessels (eg, left gastric vein, short gastric vein, esophageal and paraesophageal varices, splenorenal and gastrorenal shunts, paraumbilical and abdominal wall veins) in patients with liver cirrhosis and is probably the optimal imaging technique in this setting.