Hirofumi Koike

Quantification of Lung Perfusion Blood Volume With Dual-Energy CT: Assessment of the Severity of Acute Pulmonary Thromboembolism

OBJECTIVE The purpose of this study was to evaluate the usefulness of quantification of lung perfused blood volume (PBV) with dual-energy CT (DECT) for assessment of the severity of acute pulmonary thromboembolism (PTE). MATERIALS AND METHODS We retrospectively analyzed the records of 72 patients with PTE and 168 without PTE who underwent DECT. The PTE patients were divided into high-, intermediate-, and low-risk groups based on clinical symptoms and right ventricular dysfunction. Correlations between quantification of whole-lung PBV and clinical severity were evaluated. Also evaluated was the relation between quantification of whole-lung PBV and right-to-left ventricular diameter ratio on CT images, which was used as an indicator of right ventricular dysfunction. RESULTS In the PTE and control groups, the whole-lung PBVs were 27.6 ± 7.9 and 29.9 ± 6.8 HU with a significant difference between them (p < 0.0281). In the high-, intermediate-, and low-risk PTE groups, the whole-lung PBVs were 16.0 ± 2.9, 21.0 ± 4.2, and 31.4 ± 5.8 HU with a significant difference between them (p < 0.05). There was no significant difference in whole-lung PBV between the control group and the low-risk PTE group, but there was a significant difference between the control group and the other two PTE groups. In PTE patients, whole-lung PBV had negative correlation with right-to-left ventricular diameter ratio (R = -0.567, p < 0.001). CONCLUSION Quantification of lung PBV with DECT is useful for assessment of the clinical severity of PTE and can be used as an indicator of right ventricular dysfunction.

Quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after balloon pulmonary angioplasty (BPA): Preliminary results.

OBJECTIVES Balloon pulmonary angioplasty (BPA) is a treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Its effect on pulmonary perfusion has not been quantified; we examined the clinical significance of pulmonary blood volume (PBV) using dual-energy computed tomography (DECT) in patients with CTEPH undergoing BPA. METHODS In this retrospective study of 16 BPAs in eight female patients with CTEPH, we evaluated both-lung (n=16), right- or left-lung (n=32), and three right- or left-segment (upper, middle, and lower) (n=96) PBVs before and after BPA, using DECT. We evaluated the relationships between improvement in lung PBV and pulmonary artery (PA) pressure (PAP), cardiac index (CI), pulmonary vascular resistance (PVR), and 6-min walking distance. We measured PA enhancement (PAenh) on DECT images and calculated lung PBV/PAenh to adjust timing. RESULTS Pre- and post-BPA 6-segment lung PBV/PAenh were 0.067±0.021 and 0.077±0.019, respectively, in the treated segment (p<0.0001). There were significant positive correlations between pre- to post-BPA improvements in both-lung PBV/PAenh and PAP (R=0.69, p=0.005), PVR (R=0.56, p=0.03), and 6-min walking distance (R=0.67, p=0.01). CONCLUSIONS Improved PBV after BPA, reflecting increased lung perfusion, was positively correlated with PAP, PVR, and 6-min walking distance. Lung PBV may be an indicator of BPA treatment effect.

Clinical Significance of Late Phase of Lung Perfusion Blood Volume (Lung Perfusion Blood Volume) Quantified by Dual-Energy Computed Tomography in Patients With Pulmonary Thromboembolism

Purpose: Using dual-energy computed tomography (DECT), we quantified the lung perfusion blood volume (PBV) in the late phase, which may reflect both the pulmonary artery and systemic collateral flow. We then investigated the clinical significance of late-phase lung PBV values. Materials and Methods: We retrospectively studied 206 patients (266 scans) who underwent early-phase and late-phase DECT. The patients were divided into 2 groups depending on whether or not they had pulmonary thromboembolism (PTE) (n=94 and 112). Patients with PTE were further divided into 2 subgroups, depending on whether they had acute PTE or chronic PTE (n=66 and 28). Pulmonary artery enhancement (PAenh) was measured on DECT. We then calculated the [lung PBV/PAenh] ratio in all patients during both the early and late phases for adjustment of timing. Results: The [late-phase lung PBV/PAenh] ratio was 0.092±0.029 in the group with PTE and 0.108±0.030 in the group without PTE, showing a significant difference between the 2 groups (P<0.0001). The [early-phase lung PBV values/PAenh]/[late-phase lung PBV values/PAenh] ratio was 0.68±0.19 and 0.84±0.20, respectively, also showing a significant difference between the 2 groups (P<0.0001). Finally, the [early-phase lung PBV/PAenh]/[late-phase lung PBV/PAenh] ratio was 0.71±0.19 in patients with acute PTE and 0.56±0.16 in patients with chronic PTE, and there was a significant difference between these 2 subgroups (P=0.0004). Conclusions: It may be useful to determine late-phase lung PBV values in patients with PTE, because this parameter may reflect the systemic collateral flow, which is increased in chronic PTE.

Comparative clinical and predictive value of lung perfusion blood volume CT, lung perfusion SPECT and catheter pulmonary angiography images in patients with chronic thromboembolic pulmonary hypertension before and after balloon pulmonary angioplasty

AbstractObjectivesLung perfusion blood volume (PBV) using dual-energy computed tomography has recently become an accepted technique for diagnosing pulmonary thromboembolism. We evaluated the correlation among lung PBV, single-photon emission computed tomography (SPECT) and catheter pulmonary angiography images in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after balloon pulmonary angioplasty (BPA).MethodsIn total, 17 patients and 57 sessions were evaluated with the three modalities. Segmental lung perfusion and its improvement in lung PBV and SPECT were compared with catheter pulmonary angiography as the reference standard before and after BPA.ResultsThe sensitivity for detecting segmental perfusion defects using SPECT and lung PBV was 85% and 92%, the specificity was 99% and 99%, the accuracy was 92% and 95%, the positive predictive value was 99% and 99%, and the negative predictive value was 88% and 93%. The sensitivity for detecting segmental perfusion improvement using SPECT and lung PBV was 61% and 69%, the specificity was 75% and 83%, the accuracy was 62% and 70%, the positive predictive value was 97% and 98%, and the negative predictive value was 12% and 16%.ConclusionsLung PBV is a useful technique for evaluation of segmental lung perfusion and its improvement in patients with CTEPH.Key Points• BPA is a new treatment for patients with CTEPH.• Lung PBV images may be more sensitive for pulmonary blood flow.• The current work demonstrates that Lung PBV images are useful in evaluating patients with CTEPH. • The current work demonstrates that Lung PBV is useful in gauging the treatment effect of BPA.

Takayasu Arteritis Presenting as Unexplained Pulmonary Consolidation: A Case Report

Although Takayasu arteritis (TA) is rare as a form of chronic inflammatory arteritis, it is important that it is diagnosed early because the 10-year survival rate is only 84% to 87%. Many reported patients have been young women in East Asia. We report a case of a young woman who originally presented with unexplained pulmonary consolidation. Five years later, contrast-enhanced computed tomography (CT) imaging showed thickening of the walls of the aorta and its branches and of the main and right pulmonary artery (PA), and occlusion of the left subclavian and left PAs. A diagnosis of TA was made based on these CT findings. Patients with TA often have PA involvement, and this can be the initial site of arteritis. Therefore, TA should be included in the differential diagnosis of young women with unexplained pulmonary consolidation.

Correlation between lung perfusion blood volume and SPECT images in patients with chronic thromboembolic pulmonary hypertension by balloon pulmonary angioplasty

OBJECTIVES We evaluated the reperfusion by balloon pulmonary angioplasty (BPA) in lung PBV and SPECT images. METHODS In total, 17 patients and 57 sessions were evaluated. Pre-BPA and post-BPA lung PBV and SPECT/CT images, based on both anatomical segments and physiologic regions (upper/middle/lower) were compared. RESULTS BPA had a positive effect on most hypoperfused/unperfused segments/regions. There was generally a high rate of agreement between PBV measurements and SPECT/CT. CONCLUSIONS BPA shows promise as a treatment modality for CTEPH patients. SPECT/CT, and, to a lesser extent, PBV, were useful in indicating areas in need of balloon angioplasty.

Successful treatment of hemoptysis caused by a type 2 endoleak after thoracic endovascular aortic repair

BackgroundMassive hemoptysis is a life-threatening condition and can arise as a complication of conditions. Conversely, hemoptysis rarely occurs as a complication of a ruptured thoracic aortic aneurysm (TAA).Case presentationA 76-year-old male had a history of surgical replacement of the whole aortic arch due to a TAA. Three years after the surgery, severe hemoptysis occurred, which resulted in the patient’s emergency hospitalization at our hospital. The patient was diagnosed with ruptured pseudoaneurysms of the aortic arch. Emergency thoracic endovascular aortic repair (TEVAR) was performed. .After that, the hemoptysis stopped, and the patient was discharged. Two months later, the hemoptysis reccurred so the patient was re-admitted to our hospital. CT showed a type 2 endoleak from the bronchial artery. The anastomotic pseudoaneurysms remained. As re-rupturing of the anastomotic aneurysms due to a type 2 endoleak was suspected, transcatheter arterial embolization was performed to treat the type 2 endoleak. The patient’s hemoptysis stopped, and he was discharged.One year later, CT showed that the anastomotic pseudoaneurysms had disappeared, and the diameter of the aorta had also reduced.ConclusionWe present a case of hemoptysis caused by a type 2 endoleak that occurred after TEVAR for a ruptured TAA. The hemoptysis was secondary to aortobronchial fistulas caused by anastomotic aortic pseudoaneurysms. Transcatheter arterial embolization of the type 2 endoleak was very effective against the hemoptysis, and the pseudoaneurysms also disappeared. No such cases have been reported previously.

Quantification of lung perfusion blood volume by dual-energy CT in patients with and without chronic obstructive pulmonary disease

Purpose: In chronic obstructive pulmonary disease (COPD), pulmonary vascular alteration is one of the characteristic features. Recently, software has been used for the quantification of lung iodine perfusion blood volume (iPBV) using dual-energy CT, allowing objective evaluation. The purpose of this study was to evaluate the quantification of lung PBV with and without COPD. Materials and Methods: This study was approved by the Institutional Review Board. Sixty-two subjects who had undergone a respiratory function test within one month underwent dual-energy CT angiography. The subjects were divided into two groups: with (n = 14) and without (n = 48) COPD. We evaluated the quantification of lung iPBV in the early phase and late phase using Syngo softwarepost contrast. Associations between lung iPBV and respiratory function (forced expiratory volume in 1 second/forced vital capacity; FEV1/FVC) and the percentage area of emphysema (%LAA-950) were also evaluated. Results: In the early phase, lung iPBV values were 20.1 ± 5.5 and 30.6 ± 7.6 Hounsfield Unit (HU) in those with and without COPD, respectively, with a significant difference between them (p < 0.0001). In the late phase, the values were 12.3 ± 3.7 and 15.3 ± 4.6 HU, respectively, with no significant difference (p = 0.051). However, this could be noticed as a trend. In the early phase, there was a weak significant correlation between lung iPBV value and FEV1/FVC (R = 0.26, p = 0.047). There were significant and moderate negative correlations between lung iPBV value and %LAA-950 in early and late phases (R = −0.57, p = 0.0002; R = −0.45, p = 0.005, respectively). Conclusions: Quantification of lung iPBV reflects reduced pulmonary perfusion in patients with COPD. It may be useful for objective evaluation of the pulmonary blood flow in patients with COPD.

Pulmonary Artery Hypertension Associated With Systemic Scleroderma Correlation Among Lung Pulmonary Blood Volume, Lung Perfusion Single Photon Emission Computed Tomography, and Chest Computed Tomography Images

A 68-year–old woman had been experiencing Raynaud symptom, palpitation of the heart, and short breath in walking stairs or slopes for 7 years. Recently, these symptoms had rapidly become worse. She admitted to our hospital. At that time, she was diagnosed with systemic scleroderma (limited scleroderma). Pulmonary hypertension was pointed out by echocardiography (estimated pulmonary artery pressure 35–43 mmHg), and she was suspected as having pulmonary artery hypertension associated with systemic scleroderma. At the admission, laboratory data showed as follows: plasma d-dimer 0.2 μg/mL, IgM 419.3 mg/dL, antinuclear antibody ×640, …