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To investigate if the pretreatment dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)-based radiomics machine learning predicts the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) in breast cancer patients.Seventy-eight breast cancer patients who underwent DCE-MRI before NAC and confirmed as pCR or non-pCR were enrolled. Early enhancement mapping images of pretreatment DCE-MRI were created using subtraction formula as follows: Early enhancement mapping = (SignalThe best diagnostic performance based on F-score was achieved when both first and second order texture features with clinical information and subjective radiological findings were used (AUC = 0.77). The second best diagnostic performance was achieved with an AUC of 0.76 for first order texture features followed by an AUC of 0.76 for first and second order texture features.Pretreatment DCE-MRI can improve the prediction of pCR in breast cancer patients when all texture features with clinical information and subjective radiological findings are input to build the prediction model.

BACKGROUND The spring ligament complex (SLC) supports the medial longitudinal arch of the foot, particularly in standing. We evaluated posture-related changes in the thickness and length of the three SLC bundles and their histology. METHODS The thickness and length of the supramedial calcaneonavicular ligament (smCNL), medioplantar oblique calcaneonavicular ligament (mpoCNL), and inferoplantar calcaneonavicular ligament (iplCNL) were measured in the supine and standing positions, using a multiposture magnetic resonance imaging system, in 72 healthy adult feet. Histological examination was performed for 10 feet from five cadavers. RESULTS The smCNL thickness decreased and its length increased from the supine to the standing position (P < 0.001); no other posture-related effects were noted. Histologically, smCNL fibers overlapped along multiple directions while mpoCNL and iplCNL, fibers were oriented horizontally along the longitudinal axis and vertically along the short axis, respectively. CONCLUSION The complex, multidirectional, orientation of the smCNL allows an adaptive response to changes in loading.

Background The acoustic noise in magnetic resonance imaging (MRI) potentially depends on the measurement position and presence of a patient inside the scanner bore. Purpose To analyze the spatial characteristics of the acoustic noise by using the gradient-pulse-to-acoustic-noise transfer function (GPAN-TF) with and without a human-body phantom on the examination table. Material and Methods Acoustic noise waveforms were acquired at 80 and 110 measurement positions with and without a phantom. The GPAN-TFs µPa/(mT/m) in the coils were calculated by deconvolution. The phantom effect on the spatial distribution of the acoustic noise was assessed using the peak sound pressure levels (SPLs), mean values, peak values, and peak frequencies of the GPAN-TFs. Results The peak SPLs in all positions for the X-, Y-, and Z-gradient coils were increased by 11.1 dB, 1.4 dB, and 6.1 dB, respectively, compared with the peak SPL of the magnetic isocenter. The maximum peak SPLs among all positions of the X-, Y-, and Z-gradient coils with the phantom were increased by 4.9 dB, 7.4 dB, and 6.9 dB, respectively, relative to those without the phantom. However, the peak SPLs decreased at some positions with the phantom placed on the table (X-gradient coil = 4.6 dB, Y-gradient coil = 5.0 dB, Z-gradient coil = 8.4 dB). The most common peak frequencies were in the range of 2000–3000 Hz. Conclusion “Hotspot” areas with and without the phantom were associated with acoustic noise sources in the clinical MRI scanner and were enhanced by the phantom's presence.

BACKGROUND: Pelvic floor muscles (PFM) are important for lumbar stability. However, the relationship between lumbar and hip motion angle changes (MAC) caused by PFM contraction and each PFM’s function remains unclear. OBJECTIVE: To clarify the lumbar spine and hip motion changes produced by PFM contraction and the relationship between MAC and PFM function. METHODS: In 21 healthy females, motion angle was measured for prone hip extension movement using natural movement (NM), PFM contracting movement (PM), and reducing lumbar movement (RM) methods. The PFM functional indices were bladder base elevation distance, continuous bladder base elevation time, and pelvic floor location. RESULTS: The PM showed no significant difference in lumbar motion angle but had significantly smaller hip motion than the NM (NM; 26.1 ± 8.3, PM; 29.2 ± 11.0). MAC was significantly greater in RM (lumbar spine; 4.4 ± 3.2, hip; 5.9 ± 8.7) than in PM (lumbar spine; 0.4 ± 4.4, hip; 3.1 ± 5.1) for both the lumbar spine and hip. Lumbar spine and hip MAC of PM was significantly correlated with pelvic floor location (lumbar spine; r=-0.44, hip; r= 0.54). CONCLUSION: PFM contraction does not attenuate lumbar spine motion but reduces hip motion. MAC due to PFM contraction during lumbar movement tasks is related to the PFM functional index.

BACKGROUND Urinary tract infections (UTIs) are the most common bacterial infections in children. This study aimed to review characteristics of causative bacteria and the effectiveness of antimicrobial therapy in children with febrile UTIs. METHODS Clinical records of 108 patients (130 episodes) with febrile UTIs admitted to the Kawasaki Medical School Hospital between July 2009 and October 2016 were retrospectively reviewed. The characteristics of the causative bacteria, antibacterial therapy, and therapeutic effect were verified. RESULTS Patients were aged between 0 and 183 months (median age: 3 months). Seventy-three (67.6%) were males. Sixty-three episodes (48.5%) were diagnosed with complicated UTIs. Forty-seven episodes (36.2%) were observed in patients aged

The aim of the study was to evaluate the relationship of amide proton transfer (APT) signal characteristics in brain tumors and uninvolved brain tissue for patients with glioblastoma and those with brain metastases.Using the mDIXON 3D-APT sequence of the fast spin echo method, an APT image was obtained. The mean APT signal values of tumor core, peritumor edema, ipsilateral normal-appearing white matter (INAWM), and contralateral normal white matter (CNAWM) were obtained and compared between glioblastoma and brain metastases. Receiver operating characteristic curves were used to evaluate parameters for distinguishing between glioblastoma and brain metastases. In addition, the difference and change rate in APT signal values between tumor core and peritumoral edema (PE) and CNAWM were evaluated, respectively.The APT signal values of glioblastoma were the highest in tumor core (3.41% ± 0.49%), followed by PE (2.24% ± 0.29%), INAWM (1.35% ± 0.15%), and CNAWM (1.26% ± 0.12%, P0.001). The APT signal value of brain metastases was the highest in tumor core (2.74% ± 0.34%), followed by PE (1.86% ± 0.35%), INAWM (1.17% ± 0.13%), and CNAWM (1.2% ± 0.09%, P0.01). The APT change rate (between PE and CNAWM) was not significantly different at 78% and 56% for glioblastoma and brain metastases, respectively (P0.05).Performing APT imaging under the same parameters used in this study may aid in the identification of brain tumors.

Background The perfusion-related diffusion coefficient obtained from triexponential diffusion analysis is closely correlated with regional cerebral blood flow (rCBF), as assessed by arterial spin labeling (ASL) methods. However, this provides only a semiquantitative measure of rCBF, thereby making absolute rCBF quantification challenging. Purpose To obtain rCBF in a noninvasive manner using a novel diffusion imaging method with phase contrast (DPC), in which the total CBF from phase-contrast (PC) MRI was utilized to convert perfusion-related diffusion coefficients to rCBF values. Study type Prospective. Subjects Eleven healthy volunteers (nine men and two women; mean age, 23.9 years) participated in this study. Field strength/sequence A 3.0 T, single-shot diffusion echo-planar imaging with multiple b-values (0-3000 s/mm2 ), PC-MRI, pulsed continuous ASL, and 3D T1 -weighted fast field echo. Assessment rCBF and its correlations in the gray matter (GM) and white matter (WM) were compared between DPC and ASL methods. rCBF in the GM and WM and the GM/WM ratio were compared with the literature values obtained using [15 O]-water positron emission tomography (15 O-H2 O PET). Statistical tests Spearman's correlation coefficient and Wilcoxon signed-rank test were used. Significance was set at P Results A significant positive correlation between DPC and ASL in terms of rCBF was observed in GM (R = 0.9), whereas the correlation between the two methods was poor in WM (R = 0.09). The rCBF in GM and WM and the GM/WM ratio obtained using DPC were consistent with the literature values assessed using 15 O-H2 O PET. The rCBF value obtained using DPC was significantly higher in the GM and WM than that using ASL. Data conclusion DPC enabled noninvasive quantification of rCBF. Evidence level 2 TECHNICAL EFFICACY: Stage 1.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is performed to distinguish between benign and malignant lesions by evaluating the changes in signal intensity of the acquired image (kinetic curve). This study aimed to verify whether the existing breast DCE-MRI analyzed by the sigmoid model can accurately distinguish between benign and invasive ductal carcinoma (IDC) and predict the subtype. A total of 154 patients who underwent breast MRI for detailed breast mass examinations were included in this study (38 with benign masses and 116 with IDC. The sigmoid model involved the acquisition of images at seven timepoints in 1-min intervals to determine the change in signal intensity before and after contrast injection. From this curve, the magnitude of the increase in signal intensity in the early phase, the time to reach the maximum increase, and the slopes in the early and late phases were calculated. The Mann-Whitney U-test was used for the statistical analysis. The IDC group exhibited a significantly larger and faster signal increase in the early phase and a significantly smaller rate of increase in the late phase than the benign group (P 0.001). The luminal A-like group demonstrated a significantly longer time to reach the maximum signal increase rate than other IDC subtypes (P 0.05). The sigmoid model analysis of breast DCE-MRI can distinguish between benign lesions and IDC and may also help in predicting luminal A-like breast cancer.

This follow-up study was conducted over 30 years in a cadmium-polluted area of Japan. Urinary cadmium (U-Cd) concentration decreased by nearly half from 1986 to 2008 in men and women. However, it increased from 2008 to 2014 and maintained similar levels in 2016. Because renal atrophy may induce an increase in U-Cd, kidney volumes were determined using magnetic resonance imaging (MRI) scans in 2018. Based on the MRI results, we divided the participants into two groups, namely the normal group (n = 6, three men and three women) and the lesion group (n = 6, three men and three women). The level of urinary N-acetyl-β-d-glucosaminidase/creatinine (U-NAG/Cr) in the lesion group was significantly higher than in the normal group. The level of serum alkaline phosphatase (Al-P) was positively associated with U-Cd. Age and renal cortex volumes showed significantly negative associations. However, U-Cd and renal cortex and kidney volumes showed no significant associations. These results suggest that U-NAG and serum Al-P were sensitive biomarkers to reflect renal tubular dysfunction and bone damage caused by cadmium poisoning. Individuals chronically exposed to Cd should be observed carefully, due to the increased effect of aging on renal cortex volumes.

Objective Chlamydia pneumoniae and Mycoplasma pneumoniae are both common causes of atypical pneumonia. We conducted an annual national survey of Japanese children to screen them for C. pneumoniae infections during the M. pneumoniae epidemic season. Methods Nasopharyngeal swab specimens were collected from children aged 0–15 years with suspected acute lower respiratory tract infection due to atypical pathogens, at 85 medical facilities in Japan from June 2008 to March 2018. Specimens were tested for infection using real-time polymerase chain reaction assays. Results Of 5002 specimens tested, 1822 (36.5%) were positive for M. pneumoniae alone, 42 (0.8%) were positive for C. pneumoniae alone, and 20 (0.4%) were positive for both organisms. In children with C. pneumoniae infection, the median C. pneumoniae DNA copy number was higher in those with single infections than in those with M. pneumoniae coinfection (p = 0.08); however it did not differ significantly according to whether the children had received antibiotics prior to sample collection (p = 0.34). Conclusions The prevalence of C. pneumoniae infection was substantially lower than that of M. pneumoniae infection during the study period. The change in prevalence of C. pneumoniae was not influenced by that of M. pneumoniae. Children with single C. pneumoniae infection are likely to have had C. pneumoniae infection, while those with coinfection are likely to have been C. pneumoniae carriers.

[Purpose] To verify the reliability and validity of lower leg muscle thickness (MT) assessment along the muscle's long axis using ultrasound imaging (USI) in a sitting position. [Participants and Methods] Twenty healthy adult female participants (aged, 20.3 ± 0.9 years) were included in the study. Intra- and inter-examiner reliability of the proximal, middle, and distal MT of the tibialis anterior (TA) and medial head of the gastrocnemius (GM) were verified using USI in a sitting position. Additionally, the relationship between MT measurement using USI and muscle cross-sectional area (MCSA) measurement using magnetic resonance imaging (MRI), as well as the ankle joint's maximum muscle strength, were examined. [Results] The reliability of TA and GM MT measurement using USI was high for all regions. The relationship between MCSA measurement using MRI and MT measurement using USI showed a significant correlation in all the regions for both muscles. The relationship between ankle muscle strength and USI of MT was not significantly correlated in any region for both muscles. [Conclusion] Measurement of MT using USI is reliable and valid for MCSA, but must be combined with assessments of other factors for muscle strength.

Purpose This study aimed to clarify exercise-induced changes in intravoxel incoherent motion (IVIM) parameters obtained from diffusion-weighted imaging (DWI) of the calf muscle, as well as the relationships between IVIM parameters, perfusion, and water content in muscle tissue. Materials and methods Thirteen healthy volunteers underwent IVIM-DWI, arterial spin labeling (ASL), and multi-echo spin-echo T2 mapping of the right calf on a 3.0-T magnetic resonance imaging scanner before and after performing dorsiflexion exercise. From the data, we derived the perfusion-related diffusion coefficient (D⁎), perfusion component fraction (F), blood flow parameter (FD⁎), and restricted diffusion coefficient (D) in the tibialis anterior muscle. The muscle blood flow (MBF) and transverse relaxation time (T2) were also calculated from the ASL and multi-echo spin-echo data, respectively. We compared the parameters measured before and after exercise and assessed the relationship of each IVIM-derived perfusion parameter (D⁎, F, and FD⁎) with MBF and each diffusion parameter (D and ADC) or F with T2. Results Notably, all these parameters were significantly increased after exercise. Before exercise, the FD⁎ exhibited a significant positive correlation with the MBF, whereas no significant correlation was observed between D⁎ or F and MBF. After exercise, both D⁎ and FD⁎ exhibited significant positive correlations with MBF, whereas F was not significantly correlated with MBF. Additionally, D was significantly correlated with T2 after exercise, but not before exercise. No significant correlations were found between ADC and T2 either before or after exercise. Conclusions The IVIM analyses before and after exercise enable the simultaneous evaluation of exercise-induced changes in perfusion and water diffusion in the muscle and increases the body of information on muscle physiology.

Background Inferior vena cava flow (IVCF) and abdominal aortic flow (AAF) are essential components of the systemic circulation. Although postural changes might alter IVCF and AAF by the gravity effect, the exact details are unknown. Purpose To evaluate the effect of gravity on IVCF and AAF using a novel magnetic resonance imaging (MRI) system that can image in any position. Material and Methods Caval velocity-mapped images were obtained using the cine phase-contrast technique in the upright and supine positions with multi-posture MRI (n = 12). The mean IVCF/AAF velocity, maximum IVCF/AAF velocity, cross-sectional area of IVC/AA, mean IVCF/AAF, maximum IVCF/AAF, and heart rate in the two positions were assessed. Results The mean IVCF velocity, maximum IVCF velocity, cross-sectional area of IVC, mean IVCF, maximum IVCF, mean AAF velocity, maximum AAF velocity, mean AAF, and maximum AAF were significantly lower in the upright position compared with the supine position ( P Conclusion The effect of gravity decreases IVCF and AAF. Clarifying the effect of gravity on IVCF and AAF during a postural change may help to improve the management of patients with circulatory disease.

Meniscal morphology under full weight-loading conditions is currently unknown. This study aimed to evaluate extrusion in the medial meniscus between unloaded and upright-loaded conditions in healthy adults using upright magnetic resonance imaging (MRI) and ultrasonography and to investigate the relationship between MRI and ultrasonography in upright-loaded conditions.Eighteen healthy adult volunteers (13 men and 5 women) participated in the study. MRI and ultrasonography were performed with patients in the supine, double-leg upright (DLU), and single-leg upright (SLU) positions. Medial, anterior, and posterior extrusions of the medial meniscus against the tibial edge were evaluated and compared across the three positions. Medial extrusion correlations between MRI and ultrasonography were examined. Demographic data and hip-knee-ankle (HKA) angles were measured and correlated with changes in the medial extrusion. The medial meniscal extrusions detected via MRI and ultrasonography were compared across the three positions. Correlations were examined using Pearson's correlation coefficients.Negative correlations were found between the change in medial extrusion of the medial meniscus and HKA angle (MRI: r = -0.52, ultrasonography: r = -0.51). Although no significant differences among the three conditions were observed for the anterior and posterior extrusions of the medial meniscus, the medial extrusion of the medial meniscus was significantly greater in DLU and SLU positions than that in the supine position for MRI and ultrasonography (P 0.05). Positive correlations for the medial extrusion of the medial meniscus were found between MRI and ultrasonography in all three positions (supine: r = 0.74, DLU; r = 0.71, SLU; r = 0.61).Although no significant differences in anterior and posterior extrusions of the medial meniscus were seen across the studied positions, the medial meniscus was found to undergo significant medial extrusion during upright weight-loading conditions. The strong correlation between MRI and ultrasonography highlighted the usefulness of ultrasonography.Level IV.

DWI thermometry is affected by CSF pulsation. To achieve more accurate determination of intraventricular temperature, we compared conventional DWI (c-DWI), acceleration motion compensation DWI (aMC-DWI), and motion compensation DWI (MC-DWI) when using two different b values (commonly used b value [1000 s/mm2] and theoretically optimized b value according to the diffusion coefficient of the CSF [400 s/mm2]). Eight healthy volunteers were scanned using a 3.0-T magnetic resonance (MR) system. The temperature map was created using the diffusion coefficient from DWI with b = 1000 and 400 s/mm2, respectively. The intraventricular temperatures in the lateral ventricles (LV) with less CSF pulsation, and the third ventricle (TV), which has more CSF pulsation, were compared between three techniques using the Friedman test. We measured the body temperature in the axilla to compare it with the intraventricular temperature. With b = 1000 s/mm2, the intraventricular temperatures in TV for c-DWI were significantly higher (43.12 ± 2.86 °C) than those for the aMC-DWI (37.68 ± 1.66 °C; P

[Purpose] To compare the changes in the muscle cross-sectional area (MCSA) along the long axis of the lower leg muscles at rest and during ankle plantar flexors isometric contraction and to obtain basic information regarding the movement of lower leg muscles during ankle plantar flexors contraction. [Participants and Methods] Sixteen healthy young female participants (20.9 ± 1.2 years) were asked to sit with their ankles in a neutral ankle position. Images were obtained at rest and during isometric contraction of the ankle plantar flexors using gravity magnetic resonance imaging. The MCSAs of the triceps surae and tibialis anterior were measured. [Results] The middle region of the soleus muscle had a lower MCSA on contraction than at rest. In addition, the medial head of the gastrocnemius had a lower MCSA on contraction than at rest in the distal quarter. Moreover, the tibialis anterior had a lower MCSA at rest than on contraction in the middle region. [Conclusion] The area to be used as an indicator and the movement to be induced differ depending on the muscle during isometric contraction of the triceps surae.

The aim of the present study is to develop a simple and practical method for measuring the signal-to-noise ratio (SNR) of magnetic resonance images called combined maximum b-value and echo time (COMBET) that could be suitable for pulse sequences to which a diffusion gradient can be applied.In the COMBET method, we first obtain a signal image using the objective pulse sequence. Then, we obtain the noise image of this sequence using the diffusion gradient with the largest b-value and longest echo time. However, other imaging parameters are the same as those used for the signal image acquisition. The SNR is calculated from the mean signal intensity in the region of interest (ROI) of the signal image divided by the signal standard deviation in the ROI of the noise image after the required corrections. We compared SNRs determined using the COMBET and double echo with the longest second echo time (DELSET) methods for single-shot echo-planar imaging and fast spin-echo sequences in white mineral oil phantom, purified water phantom, human head, and upper abdomen. We used the subtraction method as the reference standard.The COMBET method could obtain the optimal noise image, whereas the DELSET method could not sufficiently suppress the long TThe COMBET method allows simple and practical SNR measurement, which is applicable to tissues with long T

PURPOSE This multi-scanner study aimed to investigate the validity of single breath-hold (BH) diffusion-weighted imaging (DWI) using simultaneous-multislice (SMS) echo-planar imaging in multiple abdominal organs to enable faster acquisition and reliable quantification of apparent diffusion coefficient (ADC). METHODS SNR, geometric distortion (GD), and ADC in a phantom; the ADC in the liver, renal cortex, paraspinal muscle, spleen, and pancreas; and the signal intensity ratio of the portal vein-to-muscle (SIRPV-M) in healthy volunteers were compared between BH- and respiratory-triggered (RT) DWI with b-values of 0 and 800 s/mm2 in two different MRI scanners. RESULTS The phantom study showed that the SNR of BH-DWI was significantly lower than that of the RT-DWI (P < 0.05 for both scanners), whereas the GD and ADC of BH-DWI did not differ significantly from those of the RT-DWI (P = 0.09-0.60). In the volunteer study, the scan times were 23 seconds for BH-DWI and 184±33 seconds for RT-DWI, respectively. The ADC of the liver in BH-DWI was significantly lower than that in RT-DWI (P < 0.05 for both scanners), whereas there were no significant differences in the ADCs of the renal cortex, paraspinal muscle, spleen, or pancreas between BH-DWI and RT-DWI (P = 0.07-0.86). The SIRPV-M in BH-DWI was significantly smaller than in RT-DWI (P < 0.05 for both scanners). CONCLUSION The proposed method enables the acquisition of abdominal diffusion-weighted images in a single BH.

[Purpose] This study aimed to clarify whether the morphological changes of the lower leg muscle occur equally in the longitudinal direction of the muscle according to changes in ankle joint position during sitting. [Participants and Methods] The participants were 15 healthy young females whose dominant lower legs were analyzed. The participants sat with the lower leg vertical to the floor with a neutral, dorsiflexed, or plantarflexed ankle position. Images were obtained from the fibular head from 290 mm distal using gravity magnetic resonance imaging. The muscle cross-sectional areas of the soleus, medial and lateral heads of the gastrocnemius, and anterior tibialis were measured. [Results] The muscle cross-sectional area of the soleus at the 1/4 proximal muscle belly in the plantarflexed position was greater than those in the other positions. The 1/4 distal part in the plantarflexed position was smaller than those in the other positions. The muscle cross-sectional area of the gastrocnemius at the 1/4 distal part in the plantarflexed position was smaller than that in the dorsiflexed position. In contrast, the muscle cross-sectional area of the tibialis anterior at the 1/4 proximal part in the dorsiflexed position was greater than those in the other positions, while that at the 1/4 distal part in the dorsiflexed position was smaller than that in the plantarflexed position. [Conclusion] In the sitting position, the morphological changes of the lower leg muscle according to changes in ankle joint position are not uniform in the longitudinal muscle direction.

[Purpose] We aimed to investigate the change rate in the cross-sectional area of each hamstring component to evaluate muscle extensibility and to contribute to the studies on hamstring strain prevention. [Participants and Methods] Fifteen healthy young males volunteered to participate in this study. They performed a knee extension test. For the measurements, we used multi-posture magnetic resonance imaging (gravity magnetic resonance imaging), the open shape of which allows performing body scanning in various positions. We measured the maximum cross-sectional area of the hamstring during the initial and stretch positions from the obtained images. Then, for each muscle, we calculated the maximum cross-sectional area change rate relative to the initial position. [Results] For all hamstring muscles, the maximum cross-sectional area during stretching was significantly smaller than that in the initial position. The maximum cross-sectional area change rate of the semimembranosus was significantly smaller than that of the other 3 muscles (there were no significant differences among these 3 muscles). [Conclusion] The results suggest that the semimembranosus has higher resistance to morphological change than the other muscles, which could be an important limiting factor for the extensibility of the hamstring muscle group.

Although febrile neutropenia (FN) is one of the most common adverse events produced by chemotherapy, its microbiological etiology is determined for only 15% to 30% of cases.We investigated the rate of viremia with common DNA viruses in patients with FN.From June 2012 to April 2014, 72 blood samples from 24 patients receiving chemotherapy, who experienced FN episodes, were examined for the presence of herpes viruses and other DNA viruses. We used real-time polymerase chain reaction assays to detect herpes simplex virus type 1 and 2, varicella zoster virus, Epstein-Barr virus, cytomegalovirus, human herpes virus types 6 and 7, BK virus and human parvovirus B19 (B19).Viruses were identified in 14 of 72 samples (19.4%). The detected etiological agents were BK virus (5 episodes), human herpes virus type 6 (4 episodes), B19 (4 episodes), Epstein-Barr virus (2 episodes), and cytomegalovirus (1 episode).Our results indicate that viral infections are common causes in patients with FN. Therefore, viruses may be responsible for FN in a large proportion of patients in whom a causative microorganism could not be identified, and this viral etiology may explain their poor response to antibiotic therapy.

To obtain detailed information in breast ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) using triexponential diffusion analysis.Diffusion-weighted images (DWI) of the breast were obtained using single-shot diffusion echo-planar imaging with 15 b-values. Mean signal intensities at each b-value were measured in the DCIS and IDC lesions and fitted with the triexponential function based on a two-step approach: slow-restricted diffusion coefficient (DThe DTriexponential analysis can provide detailed diffusion information for breast tumors that can be used to differentiate between DCIS and IDC.

Aim To date no age‐comparative study has been reported about effect of exercise on muscle pump action change, while its effect is suggested to differ in ages. This study aims to clarify the changes in muscle pump action with aging by measuring the muscle and vein area, and blood flow in lower legs. Methods Subjects were healthy volunteers and consisted of three groups: young age group (N = 20), middle age group (N = 20) and old age group (N = 16). The lower leg flexor muscle area and popliteal vein area were measured by using T1‐weighed magnetic resonance imaging at the condition pre‐ and post‐ankle exercise in three positions. Moreover, popliteal blood flow velocity was also measured using phase contrast magnetic resonance imaging. Results The elderly had the highest number of individuals who had exercise habits (p

Influenza encephalopathy is defined as an acute onset of consciousness disorders secondary to an influenza virus infection and shows neurological symptoms such as impaired consciousness, convulsions, and abnormal behavior. It commonly affects younger children, but an increasing number of cases have recently been reported in adults. The fatality related to influenza encephalopathy has decreased to 7%; however, the rate of neurologic sequelae is still high. Influenza encephalopathy cannot be detected in the brain and can cause diffuse brain edema without infiltrating the inflammatory cells. The levels of several inflammatory cytokines increase in the serum and cerebrospinal fluid, particularly in severe cases, which can contribute to the pathogenesis of influenza encephalopathy. Diagnosis is based on the development of neurological symptoms such as consciousness disturbance or convulsions, as well as the findings in electroencephalograms or brain imaging. Influenza encephalopathy is classified into several types based on its pathogenesis, and characteristic clinical courses and brain imaging findings were found to be different in each type of the classification. Treatment of influenza encephalopathy includes specific treatments such as methylprednisolone pulse therapy, in addition to supportive care that stabilizes the general condition of the patient. Epidemiologic analysis of compiled cases, development of biomarkers for the diagnosis or classification of influenza encephalopathy, and research into the effectiveness of specific treatment methods are now expected.

BACKGROUND The causative mechanisms of idiopathic normal-pressure hydrocephalus (iNPH) symptoms are currently unknown. PURPOSE To assess the dynamic changes in the apparent diffusion coefficient (ADC) during the cardiac cycle (ΔADC) of the brain before and after the lumbar tap and shunt surgery for the purpose of determining changes in hydrodynamic and biomechanical properties in the brain after cerebrospinal fluid (CSF) drainage for iNPH. STUDY TYPE Retrospective. SUBJECTS Overall, 22 patients suspected to have iNPH were examined before and after the lumbar tap and were divided into patients who showed symptomatic improvements (positive group, n = 17) and those without improvement (negative group, n = 5) after the lumbar tap. Seven patients in the positive group were examined after the shunt surgery. FIELD STRENGTH/SEQUENCE 1.5T, electrocardiographically synchronized single-shot diffusion echo-planar imaging. ASSESSMENT The frontal white matter ΔADC and mean ADC (ADCmean ) were compared between before and 24 hours after lumbar tap and from 1 week to 1 month after the shunt surgery. STATISTICAL TESTS Wilcoxon signed-rank test was used. P

Introduction The features of pneumonia in children with neurologic impairment (NI) resemble those of healthcare-associated pneumonia is defined as pneumonia occurring in the community associated with healthcare risk factors. There are currently no guidelines for the treatment of pneumonia in children with NI. Here, we assessed whether the guidelines applicable for treating pneumonia in adults could be applied to children with NI. Methods Between 2008 and 2019, we enrolled children with NI who developed pneumonia and were treated in the pediatric ward of Kawasaki Medical School Hospital. We evaluated patient characteristics, the frequency of isolation of multidrug-resistant (MDR) pathogens, and clinical outcomes. Results MDR pathogens were more frequently isolated from patients receiving tube feeding (TF) and/or with tracheostomy than from patients without these risk factors. Other risk factors, including a history of antibiotic therapy and methicillin-resistant Staphylococcus aureus isolation, recent hospitalization, residence in a nursing home or extended care facility, and low-dose, long-term macrolide therapy, did not significantly affect the frequency of MDR pathogen isolation. In patients receiving TF and/or with tracheostomy, treatment success was achieved in all cases treated with broad-spectrum antibiotics and 72.2% of cases treated with non-broad-spectrum antibiotics (P = 0.007). Conversely, among patients without these risk factors, no such difference was observed. Conclusions Our findings indicate that the guideline to select antibiotics for treating pneumonia in children with NI should be simpler and more useful than the current guidelines for adult pneumonia, based on risk factor assessment for MDR pathogens.

The purpose of this study was to determine the differences in the muscle cross-sectional area (MCSA) of the triceps surae in the supine and sitting positions using magnetic resonance imaging (MRI), and the relationship between the MCSA of the triceps surae in the sitting position and muscle thickness (MT), assessed using MRI and ultrasonography, respectively. This study included 16 healthy young male participants. The measurement positions were 90&deg, flexion of the knee joint and neutral position of the ankle joint in the sitting or supine positions. Using an open-configuration MRI system with a vertical gap and ultrasonography, we measured the MCSA and MT of the soleus muscle and the medial and lateral heads of the gastrocnemius muscle at three selected locations in the ventral part of the muscle. As a result, the 50% portion of the soleus muscle and the 25% and 50% portions of the gastrocnemius medial and lateral heads were higher in the sitting position than in the supine position. Furthermore, only 50% of the gastrocnemius medial head showed a correlation between the MCSA and MT. When using the MT of the triceps surae as an indicator of muscle volume in the sitting position, the muscle site should be considered.

Purpose To suppress olefinic signals and enable simultaneous and quantitative estimation of multiple functional parameters associated with water and lipid, we investigated a modified method using chemical shift displacement and recovery-based separation of lipid tissue (SPLIT) involving acquisitions with different inversion times (TIs), echo times (TEs), and b-values. Materials and methods Single-shot diffusion echo-planar imaging (SSD-EPI) with multiple b-values (0–3000 s/mm2) was performed without fat suppression to separate water and lipid images using the chemical shift displacement of lipid signals in the phase-encoding direction. An inversion pulse (TI = 292 ms) was applied to SSD-EPI to remove olefinic signals. Consecutively, SSD-EPI (b = 0 s/mm2) was performed with TI = 0 ms and TE = 31.8 ms for T1 and T2 measurements, respectively. Under these conditions, transverse water and lipid images at the maximum diameter of the right calf were obtained in six healthy subjects. T1, T2, and the apparent diffusion coefficients (ADC) were then calculated for the tibialis anterior (TA), gastrocnemius (GM), and soleus (SL) muscles, tibialis bone marrow (TB), and subcutaneous fat (SF). Perfusion-related (D*) and restricted diffusion coefficients (D) were calculated for the muscles. Lastly, the lipid fractions (LF) of the muscles were determined after T1 and T2 corrections. Results The modified SPLIT method facilitated sufficient separation of water and lipid images of the calf, and the inversion pulse with TI of 292 ms effectively suppressed olefinic signals. All quantitative parameters obtained with the modified SPLIT method were found to be in general agreement with those previously reported in the literature. Conclusion The modified SPLIT technique enabled sufficient suppression of olefinic signals and simultaneous acquisition of quantitative parameters including diffusion, perfusion, T1 and T2 relaxation times, and LF.

The study aimed to investigate whether intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can differentiate luminal-B from luminal-A breast cancer MATERIALS AND METHODS: Biexponential analyses of IVIM and DCE MRI were performed using a 3.0-T MRI scanner, involving 134 patients with 137 pathologically confirmed luminal-type invasive breast cancers. Luminal-type breast cancer was categorized as luminal-B breast cancer (LBBC, Ki-67 ≧ 14%) or luminal-A breast cancer (LABC, Ki-67 14%). Quantitative parameters from IVIM (pure diffusion coefficient [D], perfusion-related diffusion coefficient [D*], and fraction [f]) and DCE MRI (initial percentage of enhancement and signal enhancement ratio [SER]) were calculated. The apparent diffusion coefficient (ADC) was also calculated using monoexponential fitting. We correlated these data with the Ki-67 status.The D and ADC values of LBBC were significantly lower than those of LABC (P = 0.028, P = 0.037). The SER of LBBC was significantly higher than that of LABC (P = 0.004). A univariate analysis showed that a significantly lower D (0.847 x 10The SER derived from DCE MRI and the D derived from IVIM are associated independently with the Ki-67 status in patients with luminal-type breast cancer.

We evaluated isolates obtained from children with Mycoplasma pneumoniae infection throughout Japan during 2008–2015. The highest prevalence of macrolide-resistant M. pneumoniae was 81.6% in 2012, followed by 59.3% in 2014 and 43.6% in 2015. The prevalence of macrolide-resistant M. pneumoniae among children in Japan has decreased.

Purpose To quantify the acute effect of the head-down tilt (HDT) posture on intracranial hemodynamics and hydrodynamics. Materials and Methods We evaluated the intracranial physiological parameters, blood flow-related parameters, and brain morphology in the HDT (–6° and –12°) and the horizontal supine (HS) positions. Seven and 15 healthy subjects were scanned for each position using 3.0 T magnetic resonance imaging system. The peak-to-peak intracranial volume change, the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PGp-p), and the intracranial compliance index were calculated from the blood and CSF flow determined using a cine phase-contrast technique. The brain volumetry was conducted using SPM12. The measurements were compared using the Wilcoxon signed-rank test or a paired t-test. Results No measurements changed in the –6° HDT. The PGp-p and venous outflow of the internal jugular veins (IJVs) in the –12° HDT were significantly increased compared to the HS (P < 0.001 and P = 0.025, respectively). The cross-sectional areas of the IJVs were significantly larger (P < 0.001), and the maximum, minimum, and mean blood flow velocity of the IJVs were significantly decreased (P = 0.003, < 0.001, and = 0.001, respectively) in the –12° HDT. The mean blood flow velocities of the internal carotid arteries were decreased (P = 0.023). Neither position affected the brain volume. Conclusion Pressure gradient and venous outflow were increased in accordance with the elevation of the intracranial pressure as an acute effect of the HDT. However, the CSF was not constantly shifted from the spinal canal to the cranium. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017.

金沢大学高度モビリティ研究所 / 金沢大学理工研究域機械工学系, Convalescence of distal radius bone fracture, which is major disease for elderly people, requires speedy improvement of the contracture for wrist joint angles. The contracture is the case that wrists stiffen up and the range of their motion tends to be restricted by fixing them for long time after bone fracture. Recently, traction of the wrist during flexing and extending the wrist joint is considered to be efficient as the rehabilitation procedure. Previously, we developed an equipment that can apply the constant traction force to the wrist during flexing and extending the wrist joint. By using the equipment, we observed the dynamic motion of carpals in the wrist by radiography and found that the ratio of displacement of radius - lunate joint (R-L joint) to that of wrist angle increases by the traction. However, as the obtained images by radiography were not so clear and 2 dimensional data by projecting the texture of carpal, the displacement and rotation of carpal couldn't be measured precisely. We have developed a new equipment that can hold a wrist joint being pulled at flexion or extension posture for MRI photography. MRI can take detail 3 dimensional images. By using the equipment, the study reveals that lunar, which constitutes R-L joint as a major carpel, rotates by traction of the wrist and its rotation extends the motion range of R-L joint to dorsiflexion side. Furthermore, the interosseous distance of capitate - lunate joint (C-L joint) tends to extent by the traction at neutral and dorsiflexion positions, and it may have influence on the extension of the motion range of R-L joint.

We compared the antimicrobial susceptibility of Mycoplasma pneumoniae isolates from pediatric patients in Japan in 2011–2012 and 2015–2016, when epidemics occurred. The antimicrobial activity of macrolides and tetracyclines against M. pneumoniae infection tended to be restored in 2015–2016.

To reveal the relationship between abdominal movement and artifact, and to reveal if the transient artifact in arterial phase is caused by transient abdominal movement (TAM) in contrast-enhanced (CE) MRI. 325 CE-MRI series (206 with EOB and 119 with EGCM) were included. The abdominal movement was classified into three groups by respiratory bellows waveform (= bellows grade, BG 1–3), and MR image quality (= artifact score, AS) was graded 1–5 for the precontrast, arterial and portal venous phase, respectively. The relationship between the BG and AS was evaluated. The occurrence of transient artifact in arterial phase was compared to the degree of TAM. In the acquisitions with BG3, all images showed AS of > 2, while no images had AS of > 4 in the acquisitions with BG1. Numbers of transient artifact in the arterial phase with no-abdominal movement (NAM), mild-TAM, severe-TAM were 0 of 120, 4 of 27, 7 of 8 in EOB and 0 of 91, 1 of 4, 0 of 0 in EGCM, respectively. Image quality is highly correlated with abdominal movement. Moreover, artifact in arterial phase was not observed in NAM, which indicated abdominal movement is the direct cause of artifact.

Background Despite being a well-known but seldom encountered zoonotic pathogen, diagnosis of Yersinia pseudotuberculosis is not necessarily easy. Infected patients occasionally present with various symptoms resembling Kawasaki disease; thus discriminating the two in the acute phase is challenging. In addition to bacterial culture and serology, novel detection methods based on loop-mediated isothermal amplification (LAMP) are reported in the literature. However, the clinical utility of LAMP-based methods in comparison with the other methods is scarcely documented in the literature. Aim To clarify the clinical utility of a LAMP-based method in the diagnosis of Yersinia pseudotuberculosis infection. Methodology Inpatients admitted due to suspected Yersinia pseudotuberculosis infection during April 2008 through March 2015 were enrolled. Results of the LAMP-based method as well as culture and serology were collected and compared. Results Among 16 eligible cases, serology proved positive in 13 (81.3 %) cases, LAMP in eight (50 %) cases, and bacterial culture in four (25 %) cases. No significant difference among the three methods could be proved statistically. Although serology was the most sensitive method, it is known to miss cases such as young patients, whereas LAMP could complement all three cases missed by serology. Furthermore, LAMP can return the test result within a few hours from specimen receipt, whereas serology and bacterial culture requires days to weeks of time. Conclusion Although second to serology in sensitivity, the LAMP-based method proved its utility in making rapid diagnosis, and serving a complementary role to serology.

We compared the antimicrobial susceptibility of Mycoplasma pneumoniae isolates from pediatric patients in Japan in 2011–2012 and 2015–2016, when epidemics occurred. The antimicrobial activity of macrolides and tetracyclines against M. pneumoniae infection tended to be restored in 2015–2016., We compared the antimicrobial susceptibility of Mycoplasma pneumoniae isolates from pediatric patients in Japan in 2011–2012 and 2015–2016, when epidemics occurred. The antimicrobial activity of macrolides and tetracyclines against M. pneumoniae infection tended to be restored in 2015–2016. There was no change in the antimicrobial activity of quinolones against M. pneumoniae infection.

Zoysia is a warm-season turfgrass, which comprises 11 allotetraploid species (2n = 4x = 40), each possessing different morphological and physiological traits. To characterize the genetic systems of Zoysia plants and to analyse their structural and functional differences in individual species and accessions, we sequenced the genomes of Zoysia species using HiSeq and MiSeq platforms. As a reference sequence of Zoysia species, we generated a high-quality draft sequence of the genome of Z. japonica accession ‘Nagirizaki’ (334 Mb) in which 59,271 protein-coding genes were predicted. In parallel, draft genome sequences of Z. matrella ‘Wakaba’ and Z. pacifica ‘Zanpa’ were also generated for comparative analyses. To investigate the genetic diversity among the Zoysia species, genome sequence reads of three additional accessions, Z. japonica ‘Kyoto’, Z. japonica ‘Miyagi’ and Z. matrella ‘Chiba Fair Green’, were accumulated, and aligned against the reference genome of ‘Nagirizaki’ along with those from ‘Wakaba’ and ‘Zanpa’. As a result, we detected 7,424,163 single-nucleotide polymorphisms and 852,488 short indels among these species. The information obtained in this study will be valuable for basic studies on zoysiagrass evolution and genetics as well as for the breeding of zoysiagrasses, and is made available in the ‘Zoysia Genome Database’ at http://zoysia.kazusa.or.jp.

Our previous study showed that three CO2/cAMP-responsive elements (CCRE) CCRE1, CCRE2, and CCRE3 in the promoter of the chloroplastic β-carbonic anhydrase 1 gene in the marine diatom Phaeodactylum tricornutum (Pptca1) were critical for the cAMP-mediated transcriptional response to ambient CO2 concentration. Pptca1 was activated under CO2 limitation, but the absence of light partially disabled this low-CO2-triggered transcriptional activation. This suppression effect disappeared when CCRE2 or two of three CCREs were replaced with a NotI restriction site, strongly suggesting that light signal cross-talks with CO2 on the cAMP-signal transduction pathway that targets CCREs. The paralogous chloroplastic carbonic anhydrase gene, ptca2 was also CO2/cAMP-responsive. The upstream truncation assay of the ptca2 promoter (Pptca2) revealed a short sequence of -367 to -333 relative to the transcription-start site to be a critical regulatory region for the CO2 and light responses. This core-regulatory region comprises one CCRE1 and two CCRE2 sequences. Further detailed analysis of Pptca2 clearly indicates that two CCRE2s are the cis-element governing the CO2/light response of Pptca2. The transcriptional activation of two Pptcas in CO2 limitation was evident under illumination with a photosynthetically active light wavelength, and an artificial electron acceptor from the reduction side of PSI efficiently inhibited Pptcas activation, while neither inhibition of the linear electron transport from PSII to PSI nor inhibition of ATP synthesis showed an effect on the promoter activity, strongly suggesting a specific involvement of the redox level of the stromal side of the PSI in the CO2/light cross talk.

BACKGROUND Analysis of portal venous flow (PVF) is important when evaluating the severity and prognosis of liver disease. PVF might be altered by postural changes (ie, difference in the effects of gravity). PURPOSE To evaluate the effect of gravity on PVF using a novel MRI system, which can obtain abdominal MRIs in both the supine and the upright positions. STUDY TYPE Prospective self control. SUBJECTS Twelve healthy young male volunteers. FIELD STRENGTH/SEQUENCE Caval velocity-mapped images were obtained using the electrocardiography-triggered cine phase-contrast technique in the supine and upright positions with multiposture MRI (paired 0.4 T permanent magnets). ASSESSMENT The mean PVF velocity in the region of interest in each cardiac phase was determined. A PVF curve in the cardiac cycle was also obtained from the PVF velocity multiplied by the cross-sectional area. The mean PVF velocity, maximum PVF velocity, cross-sectional area of the PV, mean PVF, maximum PVF, and heart rate in the supine and upright positions were assessed. STATISTICAL TESTS Wilcoxon signed-rank tests were applied. P < 0.05 was considered statistically significant. RESULTS The mean PVF velocity, maximum PVF velocity, cross-sectional area of the PV, mean PVF, and maximum PVF were all significantly lower in the upright position compared with the supine position (P = 0.002 for all), with differences of 42% ± 15%, 38% ± 12%, 60% ± 17%, 24% ± 11%, and 22% ± 9.3%, respectively. However, heart rate was significantly higher (116% ± 9.2%, P = 0.003) in the upright position compared with the supine position. DATA CONCLUSION The effect of gravity during postural change from a supine to an upright position significantly decreases the PVF. Multiposture MRI allows acquisition of more detailed information on liver function. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;50:83-87.

Summary Background Genetic studies have indicated possible involvement of the upregulated calcium-nuclear factor of activated T cells pathway in the pathogenesis of Kawasaki disease. We aimed to assess safety and efficacy of ciclosporin, an immunosuppressant targeting this pathway, for protection of patients with Kawasaki disease against coronary artery abnormalities. Methods We did a randomised, open-label, blinded endpoints trial involving 22 hospitals in Japan between May 29, 2014, and Dec 27, 2016. Eligible patients predicted to be at higher risk for intravenous immunoglobulin (IVIG) resistance were randomly assigned to IVIG plus ciclosporin (5 mg/kg per day for 5 days; study treatment) or IVIG (conventional treatment) groups, stratified by risk score, age, and sex. The primary endpoint was incidence of coronary artery abnormalities using Japanese criteria during the 12-week trial, assessed in participants who received at least one dose of study drug and who visited the study institution at least once during treatment. This trial is registered to Center for Clinical Trials, Japan Medical Association, number JMA-IIA00174. Findings We enrolled 175 participants. One patient withdrew consent after enrolment and was excluded and one patient (in the study treatment group) was excluded from analysis because of lost echocardiography data. Incidence of coronary artery abnormalities was lower in the study treatment group than in the conventional treatment group (12 [14%] of 86 patients vs 27 [31%] of 87 patients; risk ratio 0·46; 95% CI 0·25–0·86; p=0·010). No difference was found in the incidence of adverse events between the groups (9% vs 7%; p=0·78). Interpretation Combined primary therapy with IVIG and ciclosporin was safe and effective for favourable coronary artery outcomes in Kawasaki disease patients who were predicted to be unresponsive to IVIG. Funding Japan Agency for Medical Research and Development (grant CCT-B-2503).

Aim In operating rooms, the occurrence of pressure ulcers caused by being in the prone position is the highest among that of pressure ulcers caused by being in other surgical positions. Thus, we investigated effects of hardness and shape of urethane foam mattresses for preventing pressure ulcers during surgery performed with patients in the prone position. We aimed to elucidate how mattresses of variable hardness and shapes affect compression and displacement of the skin and soft tissues with external force in the prone position. Material and methods We assessed effects of two shapes [rectangular cube (RC) and trapezoid cube (TC)] and four degrees of hardness (50, 87.5, 175, and 262.5 N) in each shape. We performed magnetic resonance imaging (MRI) of the iliac crests with external force while participants reclined in the prone position on eight different mattresses. Results Compression of the skin and soft tissue was significantly higher with 87.5-, 175-, and 262.5-N mattresses than that with 50-N mattresses. Skin and soft tissue displacement was higher with TC mattress than that with RC mattress, and the extent of skin surface and internal soft tissue displacement was different. Conclusions Compression of the skin and soft tissue depends on mattress hardness; however, a threshold value (175 N) for hardness exists, above which no further changes in the parameters were observed. Skin and soft tissue displacement does not depend on mattress hardness, but rather on its shape. Furthermore, mattress inclination increases skin surface displacement.

Background To evaluate more detailed information noninvasively through on diffusion and perfusion in prostate cancer (PCa) using triexponential analysis of diffusion-weighted imaging (DWI). Methods Sixty-three prostate cancer patients underwent preoperative 3.0 Tesla MRI including eight b-values DWI. Triexponential analysis was performed to obtain three diffusion coefficients (Dp, Df, Ds), as well as fractions (Fp, Ff, Fs). Each diffusion parameter for cancerous lesions and normal tissues was compared and the relationship between diffusion parameters and Gleason score (GS) was assessed. Ktrans, Ve, and the ratios of intracellular components measured in histopathological specimens were compared with diffusion parameters. Results Dp was significantly greater for cancerous lesions than normal peripheral zone (PZ) (P < 0.001), whereas Dp in transition zone (TZ) showed no significant difference (P = 0.74, 95% confidence interval (CI) = −4.69–6.48). Ds was significantly smaller for each cancerous lesions in PZ and TZ (P < 0.001, respectively). There was no significant difference in Df between cancerous lesions and normal tissues in PZ and TZ (P = 0.07, 95% CI = −0.29–0.12 and P = 0.53, 95% CI = −3.51–2.29, respectively). D obtained with biexponential analysis were significantly smaller in cancerous lesions than in normal tissue in PZ and TZ (P < 0.001 for both), while D* in PZ and TZ showed no significant difference (P = 0.14, 95% CI = −1.60–0.24 and P = 0.31, 95% CI = −3.43–1.16, respectively). Dp in PZ and TZ showed significant correlation with Ktrans (R = 0.85, P < 0.001; R = 0.81, P < 0.001, respectively), while D* in PZ obtained with biexponential analysis showed no such correlation (P = 0.08, 95% CI = −0.14–0.30). Fs was significantly correlated with intracellular space fraction evaluated in histopathological specimens in PZ and TZ cancer (R = 0.41, P < 0.05; R = 0.59, P < 0.001, respectively). Ff and Fs correlated significantly with GS in PZ and TZ cancer (PZ: R = −0.44, P < 0.05; R = 0.37, P < 0.05, TZ: R = −0.59, P < 0.05; R = 0.57, P < 0.05, respectively). Conclusion Triexponential analysis is a noninvasive approach that can provide more detailed information regarding diffusion and perfusion of PCa than biexponential analysis. J. Magn. Reson. Imaging 2015.

Our purpose in this study was to assess the relationship between contrast signal intensity (CI) and concentration of perflubutane microbubbles in a phantom experiment, and to examine the feasibility of this technique for quantitative analysis of vascularity in hepatocellular carcinoma (HCC). Microbubble solutions of the perflubutane contrast agent were prepared by mixing with purified water. We examined the relationship between CI in dB units and the concentration. Moreover, seven HCC patients were examined using real-time dynamic contrast imaging. The perfusion index was calculated from time-intensity curves generated for both HCC and surrounding liver parenchyma. We observed a linear relationship between the CIdB and the concentration in the phantom study and a higher perfusion index in the HCC lesions relative to the surrounding liver parenchyma. Dynamic contrast-enhanced ultrasonography with perflubutane microbubbles, which exhibit linear and temporally stable characteristics under continuous ultrasound exposure, allows the collection of quantitative hemodynamic information regarding HCC.