Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH.Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone.Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH.Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone.Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH.Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone.Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH.Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone.Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

Histiocytic neoplasms are rare diseases involving macrophages, dendritic cells, and monocytes. They include Langer‑ hans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and histiocytic sarcoma. Histiocytic neoplasms are characterized by varied clinical courses and prognoses, necessitating a nuanced understanding of their classification, epidemiology, and clinical manifestations. Genetic studies have revealed somatic mutations, predominantly in the MAPK pathway, suggesting a clonal neoplastic nature.This review covers the current understanding of histiocytic neoplasms, molecular pathophysiology, with a particular focus on mutations in genes such as BRAF, MAP2K1, and the PI3K-AKT signaling pathways, and evolving treatment strategies, especially focusing on LCH, ECD, RDD, and JXG. The treatment landscape has evolved with advancements in targeted therapies. BRAF inhibitors, such as vemurafenib and dabrafenib, have shown efficacy, especially in highrisk LCH cases; however, challenges remain, including relapse post-treatment discontinuation, and adverse effects.MEK inhibitors have also demonstrated effectiveness, and cobimetinib has recently been approved for use in adults.Further research is required to determine the optimal treatment duration and strategies for managing therapy inter‑ ruptions. Advancements in molecular genetics and targeted therapies have revolutionized the management of histio‑ cytic neoplasms. However, ongoing research is crucial for optimizing patient outcomes.

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH.Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone.Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

Purpose: This study aimed to compare the clinical significance of two parameters, division of standardized uptake value (SUV) of target arterial activity by background venous blood pool activity ( ­SUVA/V ) and subtraction of background venous blood pool activity from SUV of target arterial activity ­(SUVA‑V ) of carotid arteries with atherosclerotic plaques using 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT). Methods: Patients aged 50 years or more who were diagnosed with carotid artery stenosis of 50% or more with carotid Doppler ultrasonography and had torso 18F-FDG PET/CT were enrolled retrospectively and classified patients who developed cerebrovascular events (CVEs) within 5 years after 18F-FDG PET/CT scan as the active group and patients who did not experience the CVE within 5 years as an inactive group. We calculated SUVA/V and ­SUVA‑V using measurements of ­SUVmax Results: SUVA‑V ­ SUVA‑V_high , and ­SUVA‑V_low were significantly higher in the active group than in the inactive group, but neithe SUVA/V ­ SUVA‑V_high , nor ­­SUVA‑V_low showed significant differences between the active and inactive groups. Thedifference in rank between groups of SUVA‑V_high and ­SUVA‑V_low was greater than the difference in rank between groups of SUVA‑V_high and ­­SUVA‑V_low . The CVE incidence differed between SUVA‑V_high and ­­SUVA‑V_low of high carotid FDG uptake, but the CVE incidence did not differ between SUVA‑V_high and ­­SUVA‑V_low of high carotid FDG uptake. Conclusion SUVA‑V may be a more rational solution than ­SUVA/V for evaluating atherosclerotic plaque inflammation on 18F-FDG PET/CT.

Background: Peripheral nerve injury is one of the most common injuries that might occur in oral and maxillofacial surgery. The purpose of this study was to determine the effect of FK506 loaded with collagen membrane and fibrin glue on the promotion of nerve regeneration after traction nerve injury in a rat model. Methods: Thirty male Sprague-Dawley rats were divided into three groups: group A (n = 10), a sham group whose sciatic nerve was exposed without any injury; and groups B (n = 10) and C (n = 10), which underwent traction nerve injury using 200 g of traction force for 1 min. The injured nerve in group C was covered with a collagen membrane soaked with FK506 (0.5 mg/0.1 mL) and fibrin glue. Functional analysis and microscopic evaluation were performed at 2 and 4 weeks after injury. Results: The sciatic function index was − 5.78 ± 3.07 for group A, − 20.69 ± 5.22 for group B, and − 12.01 ± 4.20 for group C at 2 weeks after injury. However, at 4 weeks, the sciatic function index was − 5.58 ± 2.45 for group A, − 19.69 ± 4.81 for group B, and − 11.95 ± 1.94 for group C. In both periods, statistically significant differences were found among the groups (p<0.017). Histomorphometric evaluation revealed improved nerve regeneration in group C compared to that in group B. However, no statistical differences in axonal density were found among the three groups (p < 0.017). Conclusion Localized FK506 with collagen membrane and fibrin glue could promote axonal regeneration in a rat model of traction nerve injury.