CT findings, prognosis, and follow-up of pulmonary artery periadventitial hematoma with aortic dissection: a retrospective single-center study.

Background: Pulmonary artery periadventitial hematoma (PAPH) with aortic dissection (AD) is a rare condition but has been reported to correlate with prognosis. However, there are few cases of PAPH, and the relationship with computed tomography (CT) findings of AD are unknown. This study aimed to evaluate CT findings and early prognosis in patients with PAPH in AD. Methods: This was a retrospective analysis of data from patients with Stanford type A AD diagnosed with contrast-enhanced CT in our institution from April 2008 to February 2023; 316 patients were included in the analyses. Patients comprised a PAPH group (n=78) and a non-PAPH group (n=238). The PAPH group was further divided into a group that died within 1 week of onset (death group; n=15) and a group that survived (alive group; n=63). PAPH was classified into three grades on the basis of the CT findings, as follows: Grade 1: PAPH only in the mediastinum; Grade 2: PAPH that extended into the lung field, with/without interlobular septa; and Grade 3: PAPH with pulmonary hemorrhage. Results: Compared with the non-PAPH group, the PAPH group had higher rates of early death (P=0.001), pericardial (P<0.001) and mediastinal hemorrhage (P<0.001). When comparing the death and alive groups, there was a significant difference in the rates of inoperable case (P<0.001), Grade 3 PAPH (PAPH with pulmonary hemorrhage) (P<0.001), and hemothorax (P=0.02). Multivariable analysis showed a significant association between Grade 3 PAPH (PAPH with pulmonary hemorrhage) and early death (P=0.004). Conclusions: Standard type A AD with PAPH is not rare. Mortality was higher in the PAPH group vs. the non-PAPH group, and Grade 3 PAPH (PAPH with pulmonary hemorrhage) was a significant risk factor for early death.

Quantitative evaluation of pulmonary hypertension using 4D flow MRI: A retrospective study.

Background: Pulmonary hypertension (PH) is a severe vascular disorder that may affect 50 % of patients with heart failure. Currently, right-sided heart catheterization is required to definitively diagnose PH. However, this method is invasive and thus may not be appropriate for repeated, long-term monitoring of PH patients. This retrospective study's aim was to evaluate whether 4D flow magnetic resonance imaging (MRI) can be used to quantitively measure flow parameters to identify patients with PH. Methods: The study cohort included 97 patients recruited from a single institution and divided into three groups based on echocardiographic estimate of pulmonary artery systolic pressure (PASP): normal group with PASP<36 mmHg, borderline PH group with PASP of 37-50 mmHg, and PH group with PASP>50 mmHg. 4D flow MRI was used to quantitively assess blood flow and velocity, regurgitation, wall shear stress (WSS) and kinetic energy in the pulmonary artery trunk, right main pulmonary artery, and left pulmonary artery. Two experienced radiologists independently analyzed the MR images, blinded to clinical details. Results: We found a significant difference in WSS in the pulmonary artery trunk, right main pulmonary artery and left main pulmonary artery among the three patient groups. We also found significant differences in the kinetic energy and average through velocity in the pulmonary artery trunk and right main pulmonary artery, and significant differences in the flow rate in the right main pulmonary artery. Conclusion: These data suggest that 4D flow MRI can quantitate pulmonary artery flow parameters and distinguish between patients with and without PH.

Assessment for Carotid Atherosclerotic Plaque Using Vessel Wall Magnetic Resonance Imaging: A Multireader ROC Study to Determine Optimal Sequence for Detecting Vessel Wall Calcification.

INTRODUCTION: We aimed to compare conventional vessel wall MR imaging techniques and quantitative susceptibility mapping (QSM) to determine the optimal sequence for detecting carotid artery calcification. METHODS: Twenty-two patients who underwent carotid vessel wall MR imaging and neck CT were enrolled. Four slices of 6-mm sections from the bilateral internal carotid bifurcation were subdivided into 4 segments according to clock position (0-3, 3-6, 6-9, and 9-12) and assessed for calcification. Two blinded radiologists independently reviewed a total of 704 segments and scored the likelihood of calcification using a 5-point scale on spin-echo imaging, FLASH, and QSM. The observer performance for detecting calcification was evaluated by a multireader, multiple-case receiver operating characteristic study. Weighted κ statistics were calculated to assess interobserver agreement. RESULTS: QSM had a mean area under the receiver operating characteristic curve of 0.85, which was significantly higher than that of any other sequence (p < 0.01) and showed substantial interreader agreement (κ = 0.68). A segment with a score of 3-5 was defined as positive, and a segment with a score of 1-2 was defined as negative; the sensitivity and specificity of QSM were 0.75 and 0.87, respectively. CONCLUSION: QSM was the most reliable MR sequence for the detection of plaque calcification.

The hemodynamics of adrenal veins with four-dimensional computed tomography using quantitative time-density curve: a study based on aldosteronism patients.

Present study quantitatively analyzed adrenal venous flow using four-dimensional computed tomography (4D CT). We reviewed 4D CT images of 55 patients [mean age, 52 years ± 11 (standard deviation); 23 females] who underwent adrenal venous sampling between August 2017 and February 2021. Time-density curves were referred for the adrenal venous enhancement. The clinical factors affecting hemodynamics were assessed using uni- and multivariate linear regression analyses. The right and left adrenal veins (RAV and LAV, respectively) were visualized in all cases. Mean peak enhancement values in RAV and LAV were 247 ± 67 and 292 ± 70 Hounsfield units (P < 0.01), and were reached at 44.43 ± 6.86 and 45.39 ± 7.53 s (P < 0.01), respectively. The body mass index (BMI), plasma renin activity and potassium were significant factors influencing the peak enhancement of RAV blood flow [standardized regression coefficients, - 0.327 (P = 0.017), - 0.346 (P = 0.013), 0.426 (P = 0.016), respectively]. A linear relationship between sex and the time-to-peak was observed for RAV [standardized regression coefficient, 0.348 (P = 0.046)]. RAV had a lower contrast effect than LAV and reached its peak faster. BMI, plasma renin activity, and potassium were associated with flow density in RAV. Sex independently influenced the time-to-peak.

Differentiation Between Heterogeneous GGN and Part-Solid Nodule Using 2 D Grayscale Histogram Analysis of Thin-Section CT Image.

INTRODUCTION/BACKGROUND: To evaluate cases of surgically resected pulmonary adenocarcinoma (Ad) with heterogenous ground-glass nodules (HGGNs) or part-solid nodules (PSNs) and to clarify the differences between them, and between invasive adenocarcinoma (IVA) and minimally invasive adenocarcinoma (MIA) + adenocarcinoma in situ (AIS) using grayscale histogram analysis of thin-section computed tomography (TSCT). MATERIALS AND METHODS: 241 patients with pulmonary Ad were retrospectively classified into HGGNs and PSNs on TSCT by three thoracic radiologists. Sixty HGGNs were classified into 17 IVAs, 26 MIAs, and 17 AISs. 181 PSNs were classified into 114 IVAs, 55 MIAs, and 12 AISs. RESULTS: We found significant differences in area (P = 0.0024), relative size of solid component (P <0.0001), circumference (P <0.0001), mean CT value (P <0.0001), standard deviation of the CT value (P <0.0001), maximum CT value (P <0.0001), skewness (P <0.0001), kurtosis (P <0.0001), and entropy (P <0.0001) between HGGNs and PSNs. In HGGNs, we found significant differences in relative size of solid component (P <0.0001), mean CT value (P = 0.0005), standard deviation of CT value (P = 0.0071), maximum CT value (P = 0.0237), and skewness (P = 0.0027) between IVAs and MIA+AIS lesions. In PSNs, we found significant differences in area (P = 0.0029), relative size of solid component (P = 0.0003), circumference (P = 0.0004), mean CT value (P = 0.0011), skewness (P = 0.0009), and entropy (P = 0.0002) between IVAs and the MIA+AIS lesions. CONCLUSION: Quantitative evaluations using grayscale histogram analysis can clearly distinguish between HGGNs and PSNs, and may be useful for estimating the pathology of such lesions.

Comparing the Dosing Period in Package Inserts of Antimicrobial Agents Between Japan and the United States.

Introduction: The duration of antimicrobial therapy is a critical evaluation index of antimicrobial stewardship (AS). The inclusion of the dosing period on package inserts provides a strong reason for clinical intervention by pharmacists in cases where physicians prescribe inappropriate dosing periods. This study investigated differences in the description of dosing periods in antimicrobial package inserts between Japan and the U.S. Methods: We conducted a survey comparing differences in the dosing period of oral and injectable antimicrobials approved and marketed in Japan and the U.S. as of May 1, 2021. The Fisher exact test was used to compare the presence or absence of a description of the dosing period on the package insert between these two countries. Results: We evaluated 69 antimicrobial agents, of which 34 were oral; and 35 were injectable agents. In Japan, 20 (29.0%) of the antimicrobials had package inserts stating the dosing periods, compared with 58 (84.1%) in the U.S. (p < 0.001). Conclusions: It was found that the information on the duration of administration was missing from the package insert in Japan compared to the U.S. Lack of information on the duration of administration may lead to long-term administration by the treating physician and also make it difficult for the pharmacist to inquire about the administration. It is expected that the inclusion of scientifically-based dosing periods in all package inserts will promote AS among physicians and pharmacists who are not specialists in infectious disease therapy.

Amide Proton Transfer-Chemical Exchange Saturation Transfer Imaging of Intracranial Brain Tumors and Tumor-like Lesions: Our Experience and a Review.

Chemical exchange saturation transfer (CEST) is a molecular magnetic resonance imaging (MRI) method that can generate image contrast based on the proton exchange between labeled protons in solutes and free, bulk water protons. Amide proton transfer (APT) imaging is the most frequently reported amide-proton-based CEST technique. It generates image contrast by reflecting the associations of mobile proteins and peptides resonating at 3.5 ppm downfield from water. Although the origin of the APT signal intensity in tumors is unclear, previous studies have suggested that the APT signal intensity is increased in brain tumors due to the increased mobile protein concentrations in malignant cells in association with an increased cellularity. High-grade tumors, which demonstrate a higher proliferation than low-grade tumors, have higher densities and numbers of cells (and higher concentrations of intracellular proteins and peptides) than low-grade tumors. APT-CEST imaging studies suggest that the APT-CEST signal intensity can be used to help differentiate between benign and malignant tumors and high-grade gliomas and low-grade gliomas as well as estimate the nature of lesions. In this review, we summarize the current applications and findings of the APT-CEST imaging of various brain tumors and tumor-like lesions. We report that APT-CEST imaging can provide additional information on intracranial brain tumors and tumor-like lesions compared to the information provided by conventional MRI methods, and that it can help indicate the nature of lesions, differentiate between benign and malignant lesions, and determine therapeutic effects. Future research could initiate or improve the lesion-specific clinical applicability of APT-CEST imaging for meningioma embolization, lipoma, leukoencephalopathy, tuberous sclerosis complex, progressive multifocal leukoencephalopathy, and hippocampal sclerosis.

The infrapatellar plica of the knee: analysis of relationship with femoral trochlear chondrosis using radiographs and 3.0-T MRI.

OBJECTIVE: To assess the relationship of the infrapatellar plica (IPP) with femoral trochlear chondrosis (FTC) using radiographs and 3.0-T MRI. MATERIALS AND METHODS: Four hundred eighty-three knees of 476 patients undergoing radiography and MRI were reviewed, and 280 knees of 276 patients were included. We performed a comparison of the frequency of the IPP between men and women, and that of FTC and chondromalacia patella between knees with and without the IPP. In knees with the IPP, we analyzed the correlation between FTC and sex, age, laterality, Insall-Salvati ratio (ISR), femoral sulcus angle, tilting angle, height of insertion of the IPP to Hoffa's fat pad, and width of the IPP. RESULTS: The IPP was found in 192 of 280 knees (68.6%) overall and was more common in men than in women (100 of 132 [75.8%], 92 of 148 [62.2%], p = 0.01). FTC was observed in 26 of 280 (9.3%) and was only in knees with the IPP (knees with the IPP: 26 of 192 [13.5%], knees without the IPP: 0 of 88 [0%], p < 0.001). In knees with the IPP, ISR was significantly greater in knees with FTC (p = 0.002). ISR was the only significant factor associated with FTC (odds ratio: 2.87, 95% confidence interval: 1.14, 7.22, p = 0.03), and the cutoff value of ISR for FTC was > 1.00 with sensitivity of 69.2% and specificity of 63.9%. CONCLUSION: Presence of the IPP combined with ISR > 1.00 was correlated with FTC.

Surgically resected lung adenocarcinoma: do heterogeneous GGNs and part-solid nodules on thin-section CT show different prognosis?

PURPOSE: This study aimed to evaluate the clinical courses of patients with surgically resected stage IA pulmonary adenocarcinoma (Ad) who exhibited heterogeneous ground-glass nodules (GGNs) or part-solid nodules on thin-section computed tomography (TSCT) and to clarify the prognostic differences between them. MATERIALS AND METHODS: The cases of 242 patients with proven pulmonary Ad with heterogeneous GGN or part-solid nodule who underwent surgical resection were retrospectively reviewed. After surgery, they were examined pathologically. Disease-free survival (DFS) and overall survival (OS) were also investigated. RESULTS: There were no cases of recurrent pulmonary Ad or death from the primary disease in the heterogeneous GGN group. In the part-solid nodule group, recurrent pulmonary Ad and death from the primary disease were observed in 12 and 6 of 181 patients, respectively. Heterogeneous GGNs were associated with significantly longer DFS than part-solid nodules (p = 0.042). While, there was no significant difference in OS between the two groups (p = 0.134). Pathological diagnoses were available for all 242 patients. 181 part-solid nodules were classified into 116 invasive Ads, 54 minimally invasive Ads (MIAs), and 11 Ad in situ (AIS) lesions, and 61 heterogeneous GGNs were classified into 18 invasive Ads, 25 MIAs, and 18 AIS lesions. CONCLUSION: Heterogeneous GGNs were significantly associated with longer DFS than part-solid nodules. Pathologically, there were significant differences between the heterogeneous GGNs and part-solid nodules.

Amide proton transfer MRI differentiates between progressive multifocal leukoencephalopathy and malignant brain tumors: a pilot study.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nerve system caused by the John Cunningham virus. On MRI, PML may sometimes appear similar to primary central nervous system lymphoma (PCNSL) and glioblastoma multiforme (GBM). The purpose of this pilot study was to evaluate the potential of amide proton transfer (APT) imaging for differentiating PML from PCNSL and GBM. METHODS: Patients with PML (n = 4; two men; mean age 52.3 ± 6.1 years), PCNSL (n = 7; four women; mean age 74.4 ± 5.8 years), or GBM (n = 11; 6 men; mean age 65.0 ± 15.2 years) who underwent APT-CEST MRI between January 2021 and September 2022 were retrospectively evaluated. Magnetization transfer ratio asymmetry (MTRasym) values were measured on APT imaging using a region of interest within the lesion. Receiver operating characteristics curve analysis was used to determine diagnostic cutoffs for MTRasym. RESULTS: The mean MTRasym values were 0.005 ± 0.005 in the PML group, 0.025 ± 0.005 in the PCNSL group, and 0.025 ± 0.009 in the GBM group. There were significant differences in MTRasym between PML and PCNSL (P = 0.023), and between PML and GBM (P = 0.015). For differentiating PML from PCNSL, an MTRasym threshold of 0.0165 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100% (all). For differentiating PML from GBM, an MTRasym threshold of 0.015 gave diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 90.9%, 80.0%, and 100%, respectively. CONCLUSION: MTRasym values obtained from APT imaging allowed patients with PML to be clearly discriminated from patients with PCNSL or GBM.

Quantitative Chemical Exchange Saturation Transfer Imaging of Amide Proton Transfer Differentiates between Cerebellopontine Angle Schwannoma and Meningioma: Preliminary Results.

Vestibular schwannomas are the most common tumor at the common cerebellopontine angle, followed by meningiomas. Differentiation of these tumors is critical because of the different surgical approaches required for treatment. Recent studies have demonstrated the utility of amide proton transfer (APT)-chemical exchange saturation transfer (CEST) imaging in evaluating malignant brain tumors. However, APT imaging has not been applied in benign tumors. Here, we explored the potential of APT in differentiating between schwannomas and meningiomas at the cerebellopontine angle. We retrospectively evaluated nine patients with schwannoma and nine patients with meningioma who underwent APT-CEST MRI from November 2020 to April 2022 pre-operation. All 18 tumors were histologically diagnosed. There was a significant difference in magnetization transfer ratio asymmetry (MTRasym) values (0.033 ± 0.012 vs. 0.021 ± 0.004; p = 0.007) between the schwannoma and meningioma groups. Receiver operative curve analysis showed that MTRasym values clearly differentiated between the schwannoma and meningioma groups. At an MTRasym value threshold of 0.024, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive values for MTRasym were 88.9%, 77.8%, 80.0%, and 87.5%, respectively. Our results demonstrated the ability of MTRasym values on APT-CEST imaging to discriminate patients with schwannomas from patients with meningiomas.

Prevalence of therapeutic drug monitoring and adherence to imatinib in chronic myeloid leukemia in Japan.

OBJECTIVE: The effectiveness of imatinib, a tyrosine kinase inhibitor recommended for the treatment of chronic myeloid leukemia, is associated with high adherence and trough plasma imatinib concentrations of ~ 1,000 ng/mL. However, adherence and therapeutic drug monitoring (TDM) for imatinib have hardly been reported. This study evaluated the prevalence of TDM and adherence to imatinib for chronic myeloid leukemia in Japan. MATERIALS AND METHODS: Monthly insurance claims data for ~ 5.6 million individuals aged 20 - 74 years between June 1, 2005 and December 31, 2017 were studied. Patients with at least one prescription for imatinib were included to calculate adherence and the annual mean prevalence of TDM for imatinib. RESULTS: A total of 498 patients with 9,620 prescriptions of imatinib were included. After 2013, the number of imatinib prescriptions and the number of patients treated with imatinib were over 1,000 and 200, respectively. The mean annual prevalence of TDM for imatinib was 12.2% (95% confidence interval (CI), 8.1 - 16.1%). Antihyperuricemic drugs and steroids increased the likelihood of TDM. The medication possession ratio for assessment of adherence was 93.5% (95% CI: 91.8 - 95.5%). The annual mean prevalence of TDM for imatinib was low, although adherence was high. CONCLUSION: To encourage the measurement of plasma concentrations of imatinib in clinical settings, adding a package insert, a summary of product characteristics, and a patient information leaflet regarding the implementation of TDM is justified and warrants further attention.

Diagnosis of Chronic Thromboembolic Pulmonary Hypertension Using Quantitative Lung Perfusion Parameters Extracted From Dual-energy Computed Tomography Images.

PURPOSE: To evaluate quantified iodine mapping parameters in dual-energy computed tomography in normal patients versus those with chronic thromboembolic pulmonary hypertension (CTEPH) with and without pulmonary thromboembolism. MATERIALS AND METHODS: Using automatically quantified iodine mapping in dual-energy computed tomography, we evaluated lung relative average enhancement, standard deviation (SD), and the SD/lung relative average enhancement ratio. We compared the values for these parameters in normal patients versus those with CTEPH. We also performed a receiver operating characteristic curve analysis to determine the diagnostic cutoffs for the parameters. RESULTS: Patients constituted 41 patients (10 male [24.4%] and 31 female [75.6%]; mean age [SD]: 70.0 y [13.3]) with CTEPH and 237 (92 male [38.8%] and 145 female [61.2%]; mean age [SD]: 65.9 y [15.9]) normal patients. We found significant differences in lung relative average enhancement (34.9±6.3 vs. 26.9±6.3; P <0.0001), SD (11.6±1.9 vs. 14.7±3.3; P <0.001), and the SD/lung relative average enhancement ratio (33.7±5.0 vs. 55.7±10.4; P <0.001) between the normal and CTEPH groups, respectively. The ROC analyses demonstrated high discriminatory power (area under the curve=0.99) for using the SD/lung relative average enhancement ratio to differentiate between patients in the normal group and CTEPH group. At a threshold for the area under the curve of 44.2, diagnostic sensitivity, specificity, positive predictive value, and negative predictive value for the ratio were 92.7%, 97.5%, 86.5%, and 98.7%, respectively. CONCLUSIONS: Patients with CTEPH were well-discriminated from normal patients using the SD/lung relative average enhancement ratio.

Initial experience with intensity distribution analysis of hemodynamic parameters in the thoracic aorta using four-dimensional magnetic resonance imaging: A comparison between groups with different ejection fractions.

ABSTRACT: The purpose of this study was to investigate whether there were significant differences in the intensity distributions of thoracic aorta hemodynamic parameters between groups with different ejection fractions (EF) using four-dimensional flow magnetic resonance imaging and to investigate the relationships between each parameter.A total of 26 patients, 13 each with EF of >60% and <30%, underwent cardiac four-dimensional flow magnetic resonance imaging (EF >60%: mean age: 54 ±â€Š11.6 years, EF <30%: mean age: 49.2 ±â€Š17.2 years). The thoracic aorta was divided into the proximal and distal ascending aorta (AAo), aortic arch, and the proximal and distal descending aorta, and each section was further divided into the anterior wall, posterior wall, lesser curvature, and greater curvature. The intensity distributions of wall shear stress (WSS), energy loss (EL), and vorticity (Vort) (hemodynamic parameters) and the concordance rates between these distributions were analyzed.The concordance rate between the intensity distributions of EL and Vort was high. Only the intensity distributions of EL and Vort in the distal AAo differed significantly between the groups (P < .001). In the EF >60% group, these intensity distributions showed higher values in the greater curvature of the AAo, whereas in the EF <30% group higher values were seen in the lesser curvature of the AAo.Although there was no significant intergroup difference in the WSS intensity distribution, in the EF <30% group the WSS intensity distribution tended to exhibit higher values in the lesser curvature of the distal AAo, and the WSS intensity distribution values for the greater curvature tended to gradually increase from the arch to the proximal descending aorta.The only significant differences between the EF groups were found in the intensity distributions of EL and Vort in the distal AAo. This suggests that the distributions of atherosclerosis may be EF-dependent.

CT findings of type A acute aortic dissection that did and did not result in prehospital death.

ABSTRACT: The differences between the pathologies of cases of type A acute aortic dissection (AAD) that did and did not result in prehospital death (PHD) have not been fully elucidated.This study aimed to compare the CT findings and clarify the differences between the pathologies of such cases.Ninety four consecutive type A AAD patients between 2010 and 2020 were enrolled in this study. There were 47 males and 47 females (mean age: 69.0 ±â€Š14.4 years). The patients were divided into those that did (n = 25, 27%) and did not (n = 69, 73%) suffer PHD. We retrospectively evaluated the CT or postmortem CT findings of each case and analyzed the relationships between clinical factors (CT findings and clinical characteristics) and PHD using logistic regression analysis.Bloody pericardial effusion (96% vs 35%, P < .0001), bloody pleural effusion (40% vs 1%, P < .0001), and mediastinal hematomas (88% vs 14%, P < .0001) were significantly more common in the PHD group than in the no PHD group.In the multivariate logistic regression analysis, bloody pericardial effusion and lung consolidation were found to be significant risk factors for PHD (odds ratio: 21.29 [95% confidence intervals {CI}: 1.19-248.29] and 13.72 [95% CI: 1.79-105.06], respectively; P = .014 and P  = .012, respectively). AD affecting the abdominal aorta was identified as a significant negative risk factor for PHD (odds ratio: 0.02 [95% CI: 0.01-0.65]; P = .0042).Most PHD due to type A AAD are associated with hemorrhaging. Bleeding into the pericardium and type A AAD confined to the thoracic aorta are significant risk factors for PHD. Secondary respiratory failure might contribute to PHD in such cases.

Population Pharmacokinetic Analysis and Dosing Optimization of Prophylactic Fluconazole in Japanese Patients with Hematological Malignancy.

We conducted population pharmacokinetic (PPK) analysis and Monte Carlo simulations to determine the appropriate prophylactic dose of fluconazole to prevent invasive candidiasis in patients with hematological malignancies. Patients receiving chemotherapy or hematopoietic stem cell transplantation at Yokohama City University Hospital between November 2018 and March 2020 were included. Additionally, patients receiving oral fluconazole for prophylaxis were recruited. We set the free area under the curve/minimum inhibitory concentration (MIC) = 50 as the target and determined the largest MIC (breakpoint MIC) that could achieve more than 90% probability of target attainment. The blood fluconazole concentration of 54 patients (119 points) was used for PPK analysis. The optimal model was the one-compartment model with first-order administration and first-order elimination incorporating creatinine clearance (CLcr) as a covariate of clearance and body weight as a covariate of distribution volume. We conducted Monte Carlo simulation with fluconazole at 200 mg/day or 400 mg/day dosing schedules and patient body weight and CLcr ranging from 40 to 70 kg and 40-140 mL/min, respectively. The breakpoint MICs on the first dosing day and at steady state were 0.5-1.0 µg/mL and 1.0-2.0 µg/mL for 200 mg/day and 1.0-2.0 µg/mL and 2.0-4.0 µg/mL for 400 mg/day, respectively. The recommended dose was 400-700 mg/day for the loading dose and 200-400 mg/day for the maintenance dose. Our findings suggest that the optimal prophylactic dose of fluconazole in hematological malignancy patients depends on CLcr and body weight, and a sufficient loading and maintenance dose may be needed to completely prevent invasive candidiasis.

Effect of Balloon Pulmonary Angioplasty on Homogenization of Lung Perfusion Blood Volume by Dual-Energy Computed Tomography in Patients with Chronic Thromboembolic Pulmonary Hypertension.

OBJECTIVE: Balloon pulmonary angioplasty (BPA) is used to treat patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH); the goal is to improve pulmonary perfusion. We aimed to evaluate lung perfusion blood volume (PBV) with haemodynamic and exercise-capacity parameters to assess the efficacy of BPA in the treatment of CTEPH. METHODS: We retrospectively studied 33 patients over a 6-year period. DECT pulmonary angiography was performed before and after BPA. DECT provided iodine distribution maps; whole-lung and regional PBV images and quantification were generated using post-processing software. A mosaic pattern suggesting perfusion inhomogeneity is typical in CTEPH. Hypothetically, BPA treatment would promote homogenization that would be reflected in the calculated standard deviation. RESULTS: Lung perfusion images showed decreased heterogeneity after BPA. There was a significant difference before and after BPA in the whole-lung PBV and in the regional standard deviation for pulmonary arterial pressure (R = 0.37, p = 0.032 and R = 0.57, p = 0.006), pulmonary vascular resistance (R = 0.51, p = 0.023 and R = 0.60, p = 0.002), transtricuspid pressure gradient (R = 0.50, p = 0.0028 and R = 0.61, p = 0.0001), brain natriuretic peptide (R = 0.54, p = 0.0012 and R = 0.46, p = 0.0078), and 6-min walking distance (R = 0.59, p = 0.003 and R = 0.26, p = 0.14). The effects were especially pronounced after the first BPA procedure. CONCLUSION: Decreased lung heterogeneity may suggest BPA efficacy in treating CTEPH. After BPA treatment, improved lung PBV and improved regional standard deviation showed a strong positive correlation with haemodynamic parameters and exercise capacity, which also suggests that BPA is effective in treating CTEPH.

A case of intracranial vasospasm in a patient with extensive retropharyngeal cellulitis.

Retropharyngeal cellulitis/abscesses are deep neck infections that may become life-threatening if airway compromise occurs. This condition is more common in children than in adults, and associated intracranial vessel narrowing has been reported. We report an adult patient with extensive retropharyngeal cellulitis and intracranial vasospasm. The patient was a 62-year-old woman who presented with fever, sore throat, and neck pain. She also had uncontrolled type 2 diabetes mellitus. Leukocytosis, prolonged erythrocyte sedimentation rate, elevated C-reactive protein, and hyperglycemia were present on admission. Computed tomography and contrast-enhanced magnetic resonance imaging revealed severe swelling in the nasopharyngeal, retropharyngeal, prevertebral, and bilateral carotid spaces. Gadolinium enhancement extended to the middle cranial fossa and visceral space. Multiple stenoses in several intracranial vessels was also identified. Intravenous antibiotic therapy was initiated, the patient's symptoms resolved, and repeat imaging confirmed improvement. Intracranial vasospasm should be considered in patients with retropharyngeal cellulitis.

Species Distribution of Candidemia and Their Susceptibility in a Single Japanese University Hospital: Prior Micafungin Use Affects the Appearance of Candida parapsilosis and Elevation of Micafungin MICs in Non-parapsilosis Candida Species.

INTRODUCTION: Micafungin is a recommended echinocandin antifungal agent for candidemia treatment and prophylaxis. However, overuse of echinocandin antifungals may cause resistance. There is currently no information available regarding the low susceptibility associated with using micafungin. This study investigated the effect of micafungin use on changes in the detected Candida species and low susceptibility. METHODS: We conducted a retrospective survey and included records of Candida spp. detected in blood cultures from January 2010 to December 2018 in our hospital. Survey items included clinical outcomes at 30 days after positive cultures, patient characteristics, and drug prescription status. Patient background information included gender, previous hospitalization, stay in the intensive care unit, comorbidities, and history of surgery (within 90 days before candidemia onset) and drug exposure. Species detected and their minimum inhibitory concentrations (MICs) and amount of antifungal prescriptions by department were investigated. Risk factors for detecting C. parapsilosis and for low susceptibility to micafungin were evaluated using multivariate analysis. RESULTS: A total of 153 Candida clinical blood isolates were collected and C. albicans was the most prevalent species, followed by C. parapsilosis and C. glabrata. In the analysis by department, antifungal use and non-albicans Candida species were most frequently detected in the hematology department. Multivariate analysis showed that prior micafungin use increased the risk of C. parapsilosis (odds ratio (OR) 4.22; 95% confidence interval (CI) 1.39-12.79; p = 0.011). MIC90 of micafungin on C. glabrata and C. parapsilosis was 1.0 µg/mL. Prior micafungin use was clarified as a risk factor resulting in MIC > 0.06 µg/mL for micafungin in non-parapsilosis Candida species (OR 13.2; 95% CI 3.23-54.2; p < 0.01). CONCLUSION: Prior micafungin use increased the risk of C. parapsilosis and the MIC > 0.06 µg/mL of micafungin in non-parapsilosis Candida species. Since there are only a few antifungal options, further antifungal stewardship considering azole antifungal agents use is required.

FDG-PET vs. chemical shift MR imaging in differentiating intertrabecular metastasis from hematopoietic bone marrow hyperplasia.

PURPOSE: To evaluate the utility of SUVmax on FDG-PET and chemical shift imaging (CSI) on MRI in the differentiation of intertrabecular metastasis (ITM) from hematopoietic bone marrow hyperplasia (HBMH). PATIENTS AND METHODS: We retrospectively evaluated 54 indeterminate focal bone marrow lesions in 44 patients detected on FDG-PET. The lesions were assigned to the metastasis group (M group, 29 lesions of 24 patients) and the non-metastasis group (non-M group, 25 lesions of 20 patients) based on the follow-up or the histopathological studies. The lesions were assessed with the maximum standardized uptake value (SUVmax) on FDG-PET CT images and signal change ratio (SCR) on CSI. RESULTS: The median SUVmax were 5.62 and 2.91; the median SCR were - 0.08 and - 34.8 in M and non-M groups respectively, with significant difference (p < 0.001). With ROC curve analysis, the optimal cutoff value of SUVmax was 4.48 with a sensitivity of 72.4%, a specificity of 100%, and AUC of 0.905. The cutoff value of SCR was - 6.15 with a sensitivity of 82.8%, a specificity of 80%, and AUC of 0.818. CONCLUSION: FDG-PET and CSI on MRI are useful in distinguishing ITM from HBMH. Though their sensitivities are similar, the specificity of FDG-PET was higher than that of MRI.