Recognition of the Phanerozoic “Young Granite Gneiss” in the central Yeongnam Massif

Up to now, all the high-grade gneisses of the Korean peninsula have been regarded as Precambrian basement rocks and presence of the Phanerozoic high-grade metamorphic rocks have remained unknown. However, such granite gneiss is discovered through this study from the central Yeongnam massif near Gimcheon. SHRIMP zircon U-Pb age determinations on the granite gneiss, having well-developed gneissic foliations and migmatitic textures, reveal concordant age of ca. 250 Ma indicating the Early Triassic emplacement of this pluton, which is in contradict to the previous belief that it is a Precambrian product. Even though the granite gneiss reveals well-developed gneissic foliations and some zircons show rather low Th/U ratios, the metamorphic age has not been determined successfully. However, the age of metamorphism can be constrained as middle Triassic considering the absence of any evidences of metamorphism from the nearby granitic plutons having emplacement ages of ca. 225 Ma. Early Triassic emplacement and subsequent Middle Triassic metamorphism of the granite gneiss from the Yeongnam massif bear a remarkable resemblance to the case of South China block. We suggest the possibility that Early to Middle Triassic metamorphism of the Korean peninsula might be products of the intracontinental collisional events not directly related with the Early Triassic continental collision event

Chronic posttraumatic stress and its predictors in patients living with an implantable cardioverter defibrillator.

Patients with an implantable cardioverter defibrillator (ICD) show clinically relevant depression and anxiety, but little is known about their levels of posttraumatic stress. We assessed chronic posttraumatic stress attributable to a traumatic cardiac event and its predictors in patients at two time points after ICD placement. METHODS: We investigated 107 consecutively enrolled patients (57±14years, 62% men) on average 24±21months after ICD placement (baseline) and again 41±18months later (follow-up). All patients completed the Impact of Event Scale-Revised (IES-R) to self-rate the severity of posttraumatic stress (range 0-110). The 30% of patients with the highest IES-R scores (≥25) at baseline were defined as PTSD cases; the same threshold was applied to define PTSD caseness at follow-up. RESULTS: Posttraumatic stress increased from baseline to follow-up (19±22 vs. 25±19, p<0.001); 19% of patients had PTSD at both assessments, 12% at baseline only, and 18% at follow-up only. Female gender as well as greater peritraumatic dissociation and depression predicted greater posttraumatic stress at baseline (p-values≤0.041). Greater baseline posttraumatic stress, helplessness, alexithymia, and ≥5 shocks during follow-up all predicted greater posttraumatic stress at follow-up (p-values≤0.029). Female gender, helplessness, and depression predicted PTSD at baseline (p-values≤0.022); low education and posttraumatic stress at baseline predicted PTSD at follow-up (p-values≤0.003). CONCLUSIONS: Between 2 and 5.5years post-ICD placement chronic posttraumatic stress slightly increased and nearly one-fifth of patients had newly developed PTSD. The identified psychological predictors of long-term chronicity of posttraumatic stress might particularly inform behavioral interventions for ICD recipients

Spinal epidural hemangiomas: various types of MR imaging features with histopathologic correlation

BACKGROUND AND PURPOSE: Because of the high vascularization of hemangiomas, preoperative misinterpretation may result in unexpected intraoperative hemorrhage and incomplete resection, which results in the persistence of clinical symptoms or recurrence. Our purpose was to analyze various MR imaging features of a spinal epidural hemangioma with histopathologic correlation. MATERIALS AND METHODS: After searching through the pathology data bases in 3 hospitals, we included 14 patients (9 male and 5 female; mean age, 38 years; age range, 2-62 years) with spinal epidural hemangiomas confirmed by surgical resection after MR imaging. Three radiologists reviewed the MR imaging in consensus and categorized the features into subtypes on the basis of histopathologic findings. RESULTS: We categorized the MR imaging features as follows: type A for a cystlike mass with T1 hyperintensity (2 cases, arteriovenous type with an organized hematoma), type B for a cystlike mass with T1 isointensity (3 cases, venous type), type C for a solid hypervascular mass (7 cases, cavernous type), and type D for an epidural hematoma (2 cases, cavernous type with hematoma). Types A and B had frequent single segmental involvement (4/5), whereas types C and D had multisegmental involvement in all. Regardless of MR types, lobular contour (8/14) and a rim of low T2 signal intensity (8/14) of the mass were common. T1 hyperintensity of the mass was occasionally seen (5/14). CONCLUSIONS: Spinal epidural hemangiomas can have various MR imaging features according to their different histopathologic backgrounds. In addition to common features such as solid hypervascularity, lobular contour, and a rim of low T2 signal intensity, T1 hyperintensity or multisegmental involvement may also be a clue in the differential diagnosis of a spinal epidural hemangioma

Spinal Epidural Hemangiomas: Various Types of MR Imaging Features with Histopathologic Correlation

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