Patient-reported difficulty in activities of daily living and corresponding muscle weakness in elderly patients undergoing haemodialysis.

AIM: Patients undergoing haemodialysis have reduced muscle strength and impaired activities of daily living (ADL). We examined possible relationship between difficult ADL and corresponding muscle weakness in elderly haemodialysis patients. METHODS: This was a single-centre, cross-sectional study. Patient-reported ADL difficulty was examined using a questionnaire in six ADL using upper limbs (eating, grooming and dressing) and lower limbs (bathing, toileting and locomotion). We measured six muscle strengths by dynamometers of shoulder flexion, shoulder abduction, elbow flexion, handgrip, hip abduction and knee extension. The muscle strength with the lowest Z-score was considered as the weakest muscle strength for the patient. RESULTS: The six scores of ADL difficulty were all inversely associated with the six muscle strengths in the 81 total participants of whom 71 individuals (87.7%) had any ADL difficulty. Among the six measurements of muscle strength, handgrip strength showed the highest associations with all ADL difficulties. In 25 patients who perceived that the most difficult ADL was an activity using upper limbs, the common weakest muscle strengths were the hip abduction, handgrip and elbow flexion. In 44 patients who perceived that the most difficult ADL was an activity using lower limbs, knee extension was the most prevalent weakest muscle strength. CONCLUSION: This study suggested preferential relationship between the most difficult ADL and corresponding muscle weakness in elderly haemodialysis patients. This finding may be useful in prevention and treatment.

[A Case of Long-Term Response to Chemotherapy in Mucinous Carcinoma of the Duodenum with Multiple Distant Metastases].

Primary carcinoma of the duodenum, especially mucinous carcinoma of the duodenum, is extremely rare. We present a case of a long-term response to chemotherapy in mucinous carcinoma of the duodenum with multiple distant metastases. A 60-year-old man was admitted to our hospital with epigastric pain and jaundice. CT showed a thickening of the duodenal wall; extensive lymphadenopathy around the head of the pancreas, in the para-aortic region and the mediastinum; suspected peritoneal dissemination; lung metastases; and bone metastases. An upper gastrointestinal endoscopy revealed a duodenal stenosis in the descending limb with irregular mucosa, and a diagnosis of mucinous carcinoma of the duodenum was made on the basis of the histological analysis of the biopsy sample. Double bypass surgery involving a choledochojejunostomy and gastrojejunostomy were performed for obstruction of the duodenum and common bile duct. After FOLFOXIRI therapy was initiated, the tumors were reduced markedly. Despite withdrawal after 28 courses of chemotherapy, the patient achieved a long-term response for 10 years after the initiation of chemotherapy.

Super-resolution application of generative adversarial network on brain time-of-flight MR angiography: image quality and diagnostic utility evaluation.

OBJECTIVES: To develop a generative adversarial network (GAN) model to improve image resolution of brain time-of-flight MR angiography (TOF-MRA) and to evaluate the image quality and diagnostic utility of the reconstructed images. METHODS: We included 180 patients who underwent 1-min low-resolution (LR) and 4-min high-resolution (routine) brain TOF-MRA scans. We used 50 patients' datasets for training, 12 for quantitative image quality evaluation, and the rest for diagnostic validation. We modified a pix2pix GAN to suit TOF-MRA datasets and fine-tuned GAN-related parameters, including loss functions. Maximum intensity projection images were generated and compared using multi-scale structural similarity (MS-SSIM) and information theoretic-based statistic similarity measure (ISSM) index. Two radiologists scored vessels' visibilities using a 5-point Likert scale. Finally, we evaluated sensitivities and specificities of GAN-MRA in depicting aneurysms, stenoses, and occlusions. RESULTS: The optimal model was achieved with a lambda of 1e5 and L1 + MS-SSIM loss. Image quality metrics for GAN-MRA were higher than those for LR-MRA (MS-SSIM, 0.87 vs. 0.73; ISSM, 0.60 vs. 0.35; p.adjusted < 0.001). Vessels' visibility of GAN-MRA was superior to LR-MRA (rater A, 4.18 vs. 2.53; rater B, 4.61 vs. 2.65; p.adjusted < 0.001). In depicting vascular abnormalities, GAN-MRA showed comparable sensitivities and specificities, with greater sensitivity for aneurysm detection by one rater (93% vs. 84%, p < 0.05). CONCLUSIONS: An optimized GAN could significantly improve the image quality and vessel visibility of low-resolution brain TOF-MRA with equivalent sensitivity and specificity in detecting aneurysms, stenoses, and occlusions. KEY POINTS: • GAN could significantly improve the image quality and vessel visualization of low-resolution brain MR angiography (MRA). • With optimally adjusted training parameters, the GAN model did not degrade diagnostic performance by generating substantial false positives or false negatives. • GAN could be a promising approach for obtaining higher resolution TOF-MRA from images scanned in a fraction of time.

Nodal infiltration in endometrial cancer: a prediction model using best subset regression.

OBJECTIVES: To build preoperative prediction models with and without MRI for regional lymph node metastasis (r-LNM, pelvic and/or para-aortic LNM (PENM/PANM)) and for PANM in endometrial cancer using established risk factors. METHODS: In this retrospective two-center study, 364 patients with endometrial cancer were included: 253 in the model development and 111 in the external validation. For r-LNM and PANM, respectively, best subset regression with ten-time fivefold cross validation was conducted using ten established risk factors (4 clinical and 6 imaging factors). Models with the top 10 percentile of area under the curve (AUC) and with the fewest variables in the model development were subjected to the external validation (11 and 4 candidates, respectively, for r-LNM and PANM). Then, the models with the highest AUC were selected as the final models. Models without MRI findings were developed similarly, assuming the cases where MRI was not available. RESULTS: The final r-LNM model consisted of pelvic lymph node (PEN) ≥ 6 mm, deep myometrial invasion (DMI) on MRI, CA125, para-aortic lymph node (PAN) ≥ 6 mm, and biopsy; PANM model consisted of DMI, PAN, PEN, and CA125 (in order of correlation coefficient ß values). The AUCs were 0.85 (95%CI: 0.77-0.92) and 0.86 (0.75-0.94) for the external validation, respectively. The model without MRI for r-LNM and PANM showed AUC of 0.79 (0.68-0.89) and 0.87 (0.76-0.96), respectively. CONCLUSIONS: The prediction models created by best subset regression with cross validation showed high diagnostic performance for predicting LNM in endometrial cancer, which may avoid unnecessary lymphadenectomies. CLINICAL RELEVANCE STATEMENT: The prediction risks of lymph node metastasis (LNM) and para-aortic LNM can be easily obtained for all patients with endometrial cancer by inputting the conventional clinical information into our models. They help in the decision-making for optimal lymphadenectomy and personalized treatment. KEY POINTS: •Diagnostic performance of lymph node metastases (LNM) in endometrial cancer is low based on size criteria and can be improved by combining with other clinical information. •The optimized logistic regression model for regional LNM consists of lymph node ≥ 6 mm, deep myometrial invasion, cancer antigen-125, and biopsy, showing high diagnostic performance. •Our model predicts the preoperative risk of LNM, which may avoid unnecessary lymphadenectomies.

Placental functional assessment and its relationship to adverse pregnancy outcome: comparison of intravoxel incoherent motion (IVIM) MRI, T2-relaxation time, and umbilical artery Doppler ultrasound.

BACKGROUND: Early identification of placental insufficiency can lead to appropriate treatment selections and can improve neonates' outcomes. Possible contributions of magnetic resonance imaging (MRI) have been suggested. PURPOSE: To evaluate the prognostic capabilities of placental intravoxel incoherent motion (IVIM) parameters and T2-relaxation time, and their correlation with fetal growth and adverse outcomes, comparing umbilical artery (UmA) pulsatility index (PI). MATERIAL AND METHODS: A total of 68 singleton pregnancies at 24-40 weeks of gestation underwent placental MRI and were reviewed retrospectively. UmA-PI was measured using Doppler ultrasound by obstetricians. IVIM parameters (Dfast, Dslow, and f) were calculated with a Bayesian model fitting. First, the associations between gestational age (GA) with placental IVIM parameters, T2-relaxation time, and placental thickness (PT) were evaluated. Second, IVIM parameters, T2 value (Z-score), PT (Z-score), and UmA-PI (Z-score) were compared between ( 1) those delivering small for gestational age (SGA) and appropriate for gestational age (AGA) neonates, ( 2) emergency cesarean section (ECS), and non-ECS, and ( 3) preterm birth and full-term birth. RESULTS: Low birth weight was observed in 15/68 cases (22%). GA was significantly associated only with T2-relaxation time and PT. SGA was significantly associated with T2 value (Z-score), f, and UmA-PI (Z-score). In the ECS groups, T2 value (Z-score), f, and Dfast were significantly lower than those in non-ECS groups. All IVIM parameters and T2 values (Z-score) showed significantly lower scores in the preterm birth group. CONCLUSION: Placental f and T2 value (Z-score) had significant associations with low birth weight and clinical adverse outcomes and could be potential imaging biomarkers of placental insufficiency.

Insertable inductively coupled volumetric coils for MR microscopy in a human 7T MR system.

PURPOSE: To demonstrate the capability of insertable inductively coupled volumetric coils for MR microscopy in a human 7T MR system. METHODS: Insertable inductively coupled volume coils with diameters of 26 and 64 mm (D26 and D64 coils) targeted for monkey and mouse brain specimen sizes were designed and fabricated. These coils were placed inside the imaging volume of a transmit/receive knee coil without wired connections to the main system. Signal-to-noise ratio (SNR) evaluations were conducted with and without the insertable coils, and the g-factor maps of parallel imaging (PI) were also calculated for the D64 coil. Brain specimens were imaged using 3D T2∗ -weighted images with spatial resolution of isotropic 50 and 160 µm using D26 and D64 coils, respectively. RESULTS: Relative average (SD) SNRs compared with knee coil alone were 12.54 (0.30) and 2.37 (0.05) at the center for the D26 and D64 coils, respectively. The mean g-factors of PI with the D64 coil for the factor of 2 were less than 1.1 in the left-right and anterior-posterior directions, and around 1.5 in the superior-inferior direction or when the PI factor of 3 was used. Acceleration in two directions showed lower g-factors but suffered from intrinsic low SNR. Representative T2∗ -weighted images of the specimen showed structural details. CONCLUSION: Inductively coupled small diameter coils insertable to the knee coil demonstrated high SNR and modest PI capability. The concept was successfully used to visualize fine structures of the brain specimen. The insertable coils are easy to handle and enable MR microscopy in a human whole-body 7T MRI system.

Uncovering overlooked diversity using molecular phylogenetic approach: A case of Japanese sphaeriid clams (Bivalvia: Sphaeriidae).

Revealing the species and lineage diversity of a taxon is important for many biological studies of wildlife. In recent decades, DNA-based approaches have been widely utilised to elucidate the diversity of taxa, especially those that are difficult to distinguish based on morphological traits. This study focused on freshwater clams (Sphaeriidae) in Japan, a biodiversity hotspot of freshwater molluscs. Molecular phylogenetic approaches, including divergence time estimation, species delimitation, rarefaction, and biogeographic area estimation, were used to reveal the nature of the species diversity and its formation process, which are largely unknown. Our delimitation and rarefaction analyses suggest that Japanese sphaeriid clams consist of at least 18 delimitated lineages. This lineage diversity is relatively high compared to other Japanese freshwater molluscs, and in addition, the majority of the Japanese lineage appears to have high endemicity despite the possibility of long-distance dispersal in sphaeriid clams. Our biogeographical analyses suggest that this diversity may be due to the combination of colonisation, during the period when Japan was connected to the continent, and the relatively recent dispersal. Our results highlight the overlooked biodiversity of Japan and provide a basis for further Japanese sphaeriid research, including conservation perspectives.

Risk Stratification for Pregnancies Diagnosed With Fetal Growth Restriction Based on Placental MRI.

BACKGROUND: Diagnosis of fetal growth restriction (FGR) entails difficulties with differentiating fetuses not fulfilling their growth potential because of pathologic conditions, such as placental insufficiency, from constitutionally small fetuses. The feasibility of placental MRI for risk stratification among pregnancies diagnosed with FGR remains unexplored. PURPOSE: To explore quantitative MRI features useful to identify pregnancies with unfavorable outcomes and to assess the diagnostic performance of visual analysis of MRI to detect pregnancies with unfavorable outcomes, among pregnancies diagnosed with FGR. STUDY TYPE: Retrospective. POPULATION: Thirteen pregnancies with unfavorable outcomes (preterm emergency cesarean section or intrauterine fetal death) and 11 pregnancies with favorable outcomes performed MRI at gestational weeks 21-36. FIELD STRENGTH/SEQUENCE: A 5-T, half-Fourier-acquired single-shot turbo spin echo (HASTE), spin-echo echo-planar imaging (SE-EPI) and T2 map derived from SE-EPI. ASSESSMENT: Placental size on HASTE sequences and T2 mapping-based histogram features were extracted. Three radiologists qualitatively evaluated the visibility of maternal cotyledon on HASTE and SE-EPI sequences with echo times (TEs) = 60, 90, and 120 msec using 3-point Likert scales: 0, absent; 1, equivocal; and 2, present. STATISTICAL TESTS: Welch's t-test or Mann-Whitney U test for quantitative features between the favorable and unfavorable outcome groups. Areas under the receiver operating curves (AUCs) of the three readers' visual analyses to detect pregnancies with unfavorable outcomes. A P value of <0.05 was inferred as statistically significant. RESULTS: Placental size (major and minor axis, estimated area of placental bed, and volume of placenta) and T2 mapping-based histogram features (mean, skewness, and kurtosis) were statistically significantly different between the two groups. Visual analysis of HASTE and SE-EPI with TE = 60 msec showed AUCs of 0.80-0.86 to detect pregnancies with unfavorable outcomes. DATA CONCLUSION: Placental size, histogram features, and visual analysis of placental MRI may allow for risk stratification regarding outcomes among pregnancies diagnosed with FGR. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 5.

Deep learning-based algorithm improved radiologists' performance in bone metastases detection on CT.

OBJECTIVES: To develop and evaluate a deep learning-based algorithm (DLA) for automatic detection of bone metastases on CT. METHODS: This retrospective study included CT scans acquired at a single institution between 2009 and 2019. Positive scans with bone metastases and negative scans without bone metastasis were collected to train the DLA. Another 50 positive and 50 negative scans were collected separately from the training dataset and were divided into validation and test datasets at a 2:3 ratio. The clinical efficacy of the DLA was evaluated in an observer study with board-certified radiologists. Jackknife alternative free-response receiver operating characteristic analysis was used to evaluate observer performance. RESULTS: A total of 269 positive scans including 1375 bone metastases and 463 negative scans were collected for the training dataset. The number of lesions identified in the validation and test datasets was 49 and 75, respectively. The DLA achieved a sensitivity of 89.8% (44 of 49) with 0.775 false positives per case for the validation dataset and 82.7% (62 of 75) with 0.617 false positives per case for the test dataset. With the DLA, the overall performance of nine radiologists with reference to the weighted alternative free-response receiver operating characteristic figure of merit improved from 0.746 to 0.899 (p < .001). Furthermore, the mean interpretation time per case decreased from 168 to 85 s (p = .004). CONCLUSION: With the aid of the algorithm, the overall performance of radiologists in bone metastases detection improved, and the interpretation time decreased at the same time. KEY POINTS: • A deep learning-based algorithm for automatic detection of bone metastases on CT was developed. • In the observer study, overall performance of radiologists in bone metastases detection improved significantly with the aid of the algorithm. • Radiologists' interpretation time decreased at the same time.

Free-breathing abdominal T1 mapping using an optimized MR fingerprinting sequence.

In this work, we propose a free-breathing magnetic resonance fingerprinting (MRF) method that can be used to obtain B1+ -robust quantitative T1 maps of the abdomen in a clinically acceptable time. A three-dimensional MRF sequence with a radial stack-of-stars trajectory was implemented, and its k-space acquisition ordering was adjusted to improve motion-robustness in the context of MRF. The flip angle pattern was optimized using the Cramér-Rao Lower Bound, and the encoding efficiency of sequences with 300, 600, 900 and 1800 flip angles was evaluated. To validate the sequence, a movable multicompartment phantom was developed. Reference multiparametric maps were acquired under stationary conditions using a previously validated MRF method. Periodic motion of the phantom was used to investigate the motion-robustness of the proposed sequence. The best performing sequence length (600 flip angles) was used to image the abdomen during a free-breathing volunteer scan. When using a series of 600 or more flip angles, the estimated T1 values in the stationary phantom showed good agreement with the reference scan. Phantom experiments revealed that motion-related artifacts can appear in the quantitative maps and confirmed that a motion-robust k-space ordering is essential. The in vivo scan demonstrated that the proposed sequence can produce clean parameter maps while the subject breathes freely. Using this sequence, it is possible to generate B1+ -robust quantitative maps of T1 and B1+ next to M0 -weighted images under free-breathing conditions at a clinically usable resolution within 5 min.

Evaluation of Weighted Diffusion Subtraction for Detection of Clinically Significant Prostate Cancer.

BACKGROUND: Diffusion-weighted imaging (DWI) is an important method for clinically significant prostate cancer (csPCa) diagnosis; however, the Prostate Imaging-Reporting and Data System (PI-RADS) requires the subjective assessment of "markedly hypointense or not" on apparent diffusion coefficient (ADC) map. We hypothesize that weighted diffusion subtraction (WDS) images, created by weighted subtraction of high and low b-value DWIs, might better show areas of ADC values below a set threshold, thus decreasing the subjectivity of the assessment. PURPOSE: To evaluate the diagnostic ability of WDS for csPCa by comparing scores based on WDS images (DWI/WDS) with those based on PI-RADS DWI (DWI/ADC). STUDY TYPE: Retrospective. SUBJECTS: Eighty-six PCa patients. FIELD STRENGTH/SEQUENCES: 3.0 T; DWI. ASSESSMENT: Four readers assessed the probability of csPCa in lesions (overall, in the peripheral zone [PZ] and transitional zone [TZ]) using 5-point DWI/ADC and DWI/WDS scores. Prostatectomy specimens were the reference standard. ADC values and contrast between csPCa and normal prostate tissue on ADC maps and WDS images were calculated with reference to the pathological map. STATISTICAL TESTS: Diagnostic ability was evaluated by Jackknife alternative free-response receiver-operating characteristic curve. Figure of merit (FOM), sensitivity, and positive predictive value (PPV) between the DWI/ADC and DWI/WDS scores were compared using paired t-test. Inter-reader agreement was analyzed using κ statistics, and the significance probability was calculated using the Z statistic. Wilcoxon signed-rank test was used to compare contrast between csPCa and normal prostate tissue on ADC maps and WDS images. A P value <0.05 was considered statistically significant. RESULTS: FOM and sensitivity of the DWI/WDS scores were significantly better than those of the DWI/ADC scores overall, in the PZ and TZ (FOM: overall, 0.715 vs. 0.783; PZ, 0.756 vs. 0.815; TZ, 0.653 vs. 0.738. Sensitivity: overall, 0.512 vs. 0.607; PZ, 0.485 vs. 0.573; TZ, 0.636 vs. 0.761). For PPV, a statistically significant difference was observed overall (0.727 vs. 0.777). The κ value of DWI/WDS score was significantly higher than that of DWI/ADC score overall and in the PZ (overall, 0.614 vs. 0.792; PZ, 0.609 vs. 0.797). Contrast was significantly higher overall in the PZ and TZ in WDS images (median, 1.26, 1.19, and 1.61) than in ADC maps (0.46, 0.47, and 0.41). DATA CONCLUSION: WDS images performed better than ADC maps in the diagnosis of csPCa and in inter-reader agreement of the diagnosis. LEVEL OF EVIDENCE: 4 Technical Efficacy Stage: 2.

Substrate membrane bearing close-packed array of micron-level pillars incrassates air-exposed three-dimensional epidermal equivalent model.

BACKGROUND: We showed previously that a thick three-dimensional epidermal equivalent can be constructed with passaged keratinocytes on a patterned surface. MATERIAL AND METHODS: We first carried out computer simulations of a three-dimensional epidermal equivalent model built on close-packed arrays of 10 µm, 15 µm, 20 µm, 30 µm, and 60 µm diameter pillars. Based on these predictions, we evaluated epidermal equivalents built on a series of porous plastic membranes bearing arrays of pillars 15 µm, 20 µm, 25 µm, 30 µm, and 50 µm in diameter. RESULTS: The simulations predicted that a model having near-physiological thickness would be formed on 15 ~ 30 µm pillars. In the results of in vitro study, the thickest epidermal equivalent was obtained on the 20 µm pillars. Epidermal differentiation markers, filaggrin and loricrin, were expressed at the upper layer of the epidermal equivalent model, and tight-junction proteins, claudin-1 and ZO-1, were expressed on the cell membranes. BrdU-positive cells were observed at the base and also at the top of the pillars. CONCLUSION: The results of the study suggested that mathematical modeling might be a useful tool to guide biological studies.

Diffusion-weighted imaging of uterine adenomyosis: Correlation with clinical backgrounds and comparison with malignant uterine tumors.

AIM: To elucidate correlation between signal intensity on diffusion-weighted images (SI-DWI) and clinical backgrounds for uterine adenomyosis and to compare SI-DWI of adenomyosis and malignant uterine tumors. METHODS: This study examined 46 adenomyosis patients diagnosed using magnetic resonance imaging and 25 patients with surgically confirmed malignant uterine myometrial tumor. First, adenomyosis cases were classified visually into high-intensity and low-intensity groups based on the SI-DWI compared with that of normal uterine myometrium. Secondly, correlation was assessed between SI-DWI of adenomyosis and patient clinical background information such as age, menopausal status, menstrual cycle and dysmenorrhea severity. Third, quantitative comparison was made of low-intensity adenomyosis (LIA), high-intensity adenomyosis (HIA) and malignant tumor groups for the signal intensity ratio (SIR) on DWI and the apparent diffusion coefficient (ADC). Their diagnostic performance was evaluated using logistic regression analysis and receiver operating characteristic (ROC) analysis. RESULTS: The 46 adenomyosis cases were classified as 26 low-intensity and 20 high-intensity cases. Significant correlation was found only for menstrual cycle phases. HIA had significantly lower SIR and higher ADC than malignant tumor. The ADC of HIA was significantly higher than that of LIA. The combination of SIR and ADC showed excellent diagnostic performance (area under ROC curve, 0.99). CONCLUSION: There is a variation in signal intensity on DWI of uterine adenomyosis and it is associated with menstrual cycle phase. Adenomyosis with high signal intensity on DWI can be differentiated from malignant lesions by its lower signal intensity on DWI and higher ADC than that found for malignant uterine tumors, however overlaps exist.

Emergency surgery for hemobilia due to hepatic artery pseudoaneurysm rupture complicated by Mirizzi syndrome type II: a case report.

BACKGROUND: Hemobilia refers to bleeding into the biliary tract. Hepatic artery pseudoaneurysm (HAP) rupture is an uncommon cause of hemobilia, and cases of HAP associated with Mirizzi syndrome are extremely rare. Although transarterial embolization is recommended as the first-line treatment for hemobilia, surgery is sometimes required. CASE PRESENTATION: A 76-year-old woman was referred to our hospital with epigastric pain. She was febrile and had conjunctival icterus and epigastric tenderness. Laboratory tests revealed abnormal white blood cell count and liver function. An abdominal computed tomography (CT) revealed multiple calculi in the gallbladder, an incarcerated calculus in the cystic duct, and a slightly dilated common hepatic duct. Based on examination findings, she was diagnosed with Mirizzi syndrome type I, complicated by cholangitis. Intravenous antibiotics were administered, and we performed endoscopic retrograde cholangiopancreatography (ERCP) to place a drainage tube. The fever persisted; therefore, contrast-enhanced CT (CECT) was performed. This revealed portal vein thrombosis and hepatic abscesses; therefore, heparin infusion was administered. The following day, she complained of melena, and laboratory tests showed that she was anemic. ERCP was performed to change the drainage tube in the bile duct; however, bleeding from the papilla of Vater was observed. CECT demonstrated a right HAP with high-density fluid in the gallbladder and gallbladder perforation. Finally, she was diagnosed with hemobilia caused by HAP rupture, and emergency surgery was performed to secure hemostasis and control the infection. During laparotomy, we found that a right HAP had ruptured into the gallbladder. The gallbladder made a cholecystobiliary fistula, which indicated Mirizzi syndrome type II. Although we tried to repair the right hepatic artery, we later ligated it due to arterial wall vulnerability. Then, we performed subtotal cholecystectomy and inserted a T-tube into the common bile duct. There were no postoperative complications except for minor leakage from the T-tube insertion site. The patient was discharged after a total hospital stay of 7 weeks. CONCLUSIONS: We experienced an extremely rare case of emergency definitive surgery for hemobilia due to HAP rupture complicated by Mirizzi syndrome type II. Surgery might be indicated when controlling underlying infections was required.

Evaluation of image quality of pituitary dynamic contrast-enhanced MRI using time-resolved angiography with interleaved stochastic trajectories (TWIST) and iterative reconstruction TWIST (IT-TWIST).

BACKGROUND: Time-resolved angiography with interleaved stochastic trajectories (TWIST) is a keyhole imaging with frequent sampling of central k-space data and view-sharing for the peripheral k-space of dynamic phases. IT-TWIST is a technique to reconstruct images with a smaller temporal footprint using the same raw data obtained with TWIST by iterative reconstruction. PURPOSE: To compare image quality between TWIST and IT-TWIST in 3D pituitary DCE-MRI. STUDY TYPE: Retrospective observation study. POPULATION: Fifty-one patients (23 men, 28 women) who underwent 3D pituitary DCE-MRI using TWIST between July 2016 and April 2017. FIELD STRENGTH/SEQUENCE: 3T/TWIST and IT-TWIST. ASSESSMENT: Visual evaluation was conducted for image quality of delineation of the pituitary stalk and posterior lobe during the early arterial phase, cerebral white matter near the sella turcica, and the mass lesion. Bolus sharpness of the pituitary stalk, posterior lobe, and bilateral cavernous sinus was evaluated on the enhancement slope map calculated from TWIST and IT-TWIST. Temporal stability of intensity of the nonenhanced area was evaluated on temporal standard deviation (SD) maps calculated from TWIST and IT-TWIST. STATISTICAL TESTS: Paired t-test or Wilcoxon rank-sum test was used to test the differences between TWIST and IT-TWIST in both visual evaluation and region of interest evaluation. RESULTS: Scores of visual evaluations for IT-TWIST were significantly better than those for TWIST (P < 0.001) in all items. Enhancement slope for IT-TWIST was significantly higher than that for TWIST in posterior lobe, and right and left cavernous sinus (P < 0.001). Temporal SD for IT-TWIST was significantly lower than that for TWIST in all items, with statistical significance (P < 0.001). DATA CONCLUSION: IT-TWIST yielded better visualization, and better enhancement slope, and less temporal SD compared with TWIST in 3D pituitary DCE-MRI. Evidence Level: 4 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1497-1506.

Efficacies and Related Issues of Ustekinumab in Japanese Patients with Crohn's Disease: A Preliminary Study.

INTRODUCTION: Ustekinumab (UST) is an antibody to the p40 subunit of interleukins 12 and 23 in Crohn's disease (CD) patients. Few reports are available on CD in the Asian scenario. OBJECTIVE: We evaluated UST's efficacy in inducing remission and its maintenance in Japanese CD patients. METHODS: This retrospective study was conducted in UST-treated CD patients at our center. The primary endpoint was the clinical remission rate at week 8; the major secondary endpoints were the clinical remission rate at week 24 or 48, change in CD activity index (CDAI) and biomarkers, endoscopic efficacy, and cumulative remission maintenance rate. RESULTS: The clinical remission rates at weeks 8, 24, and 48 were 44.4, 66.7, and 50.0%, respectively. Delayed response was shown by 22.2% of the patients; they achieved remission by week 24. The baseline CDAI was significantly lower in the remission group than in the nonremission group at week 8 (95% CI 0.89-0.99; p = 0.03). The cumulative remission maintenance rates at 6 and 12 months were 82.4 and 49.8%, respectively. Loss of response (LOR) was noted in 22.2% of the patients within 1 year. The endoscopic response and mucosal healing rate were 52.6 and 5.3%, respectively. Rapid improvements in serum albumin levels were observed at weeks 8 (p = 0.06), 24 (p < 0.01), and 48 (p = 0.01) from the baseline in active cases at baseline. CONCLUSIONS: UST is effective for remission induction and maintenance, especially in those with lower CD activity, however, may result in delayed response or LOR.

Acceleration of 2D-MR fingerprinting by reducing the number of echoes with increased in-plane resolution: a volunteer study.

OBJECTIVE: To compare the absolute values and repeatability of magnetic resonance fingerprinting (MRF) with 3000 and 1500 echoes/slice acquired in 41 s and 20 s (MRF3k and MRF1.5k, respectively). MATERIALS AND METHODS: MRF3k and MRF1.5k scans based on fast imaging with steady precession (FISP) were conducted using a 3 T scanner. Inter-scan agreement and intra-scan repeatability were investigated in 41 and 28 subjects, respectively. Region-of-interest (ROI) analysis was conducted on T1 values of MRF3k by two raters, and their agreement was evaluated using intraclass correlation coefficients (ICCs). Between MRF3k and MRF1.5k, differences in T1 and T2 values and inter-measurement correlation coefficients (CCs) were investigated. Intra-measurement repeatability was evaluated using coefficients of variation (CVs). A p value < 0.05 was considered statistically significant. RESULTS: The ICCs of ROI measurements were 0.77-0.96. Differences were observed between the two MRF scans, but the CCs of the overall ROIs were 0.99 and 0.97 for the T1 and T2 values, respectively. The mean and median CVs of repeatability were equal to or less than 1.58% and 3.13% in each of the ROIs for T1 and T2, respectively; there were some significant differences between MRF3k and MRF1.5k, but they were small, measuring less than 1%. DISCUSSION: Both MRF3k and MRF1.5k had high repeatability, and a strong to very strong correlation was observed, with a trend toward slightly higher values in MRF1.5k.

Biphasic clinical course of a ruptured right gastric artery aneurysm caused by segmental arterial mediolysis: a case report.

BACKGROUND: Gastric artery aneurysms are rarely caused by segmental arterial mediolysis (SAM), a condition that often involves multiple vessels. The clinical course of SAM after vessel rupture may vary depending on the involved vessels. For example, the "double-rupture phenomenon" observed following the rupture of the splenic artery aneurysm manifests as a biphasic and relatively slow clinical course. Even in cases of rupture of gastric artery aneurysm, the double-rupture phenomenon has only been reported in two cases so far. However, the rupture was not caused by SAM in either case. Herein, we present the apparent first case of a right gastric artery (RGA) aneurysm rupture caused by SAM that presented with a biphasic clinical course, possibly due to the double-rupture phenomenon. CASE PRESENTATION: A 54-year-old woman was transferred to the emergency department with severe abdominal pain and a cold sweat for a duration of 3 h. She had developed mild abdominal pain and nausea 3 days earlier. Her vital signs were stable. Physical examination revealed tenderness in the epigastric area. Abdominal contrast-enhanced computed tomography revealed an RGA aneurysm with contrast media extravasation. A diagnosis of hemoperitoneum following a ruptured RGA aneurysm was made, and the patient underwent angiography. However, this modality did not reveal any extravasation from the RGA due to an interruption in the peripheral branch of the artery. Nevertheless, to prevent major bleeding, we performed coil embolization at the point of interruption in the RGA, which we suspected to be a ruptured aneurysm. A distal gastrectomy with Roux-en-Y reconstruction for aneurysm resection was performed the following day. There were no postoperative complications, and the patient was discharged 17 days after surgery. Histologically, the RGA demonstrated multiple vacuoles in the medial muscle layer, which were characteristic of SAM. CONCLUSIONS: An RGA aneurysm rupture should be considered a differential diagnosis in patients presenting with hemoperitoneum with a slow or biphasic clinical course.

Temporal Subtraction of Serial CT Images with Large Deformation Diffeomorphic Metric Mapping in the Identification of Bone Metastases.

Purpose To determine the improvement of radiologist efficiency and performance in the detection of bone metastases at serial follow-up computed tomography (CT) by using a temporal subtraction (TS) technique based on an advanced nonrigid image registration algorithm. Materials and Methods This retrospective study was approved by the institutional review board, and informed consent was waived. CT image pairs (previous and current scans of the torso) in 60 patients with cancer (primary lesion location: prostate, n = 14; breast, n = 16; lung, n = 20; liver, n = 10) were included. These consisted of 30 positive cases with a total of 65 bone metastases depicted only on current images and confirmed by two radiologists who had access to additional imaging examinations and clinical courses and 30 matched negative control cases (no bone metastases). Previous CT images were semiautomatically registered to current CT images by the algorithm, and TS images were created. Seven radiologists independently interpreted CT image pairs to identify newly developed bone metastases without and with TS images with an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Reading time was recorded, and usefulness was evaluated with subjective scores of 1-5, with 5 being extremely useful and 1 being useless. Significance of these values was tested with the Wilcoxon signed-rank test. Results The subtraction images depicted various types of bone metastases (osteolytic, n = 28; osteoblastic, n = 26; mixed osteolytic and blastic, n = 11) as temporal changes. The average reading time was significantly reduced (384.3 vs 286.8 seconds; Wilcoxon signed rank test, P = .028). The average figure-of-merit value increased from 0.758 to 0.835; however, this difference was not significant (JAFROC analysis, P = .092). The subjective usefulness survey response showed a median score of 5 for use of the technique (range, 3-5). Conclusion TS images obtained from serial CT scans using nonrigid registration successfully depicted newly developed bone metastases and showed promise for their efficient detection. © RSNA, 2017 Online supplemental material is available for this article.

MR imaging of uterine morphology and dynamic changes during lactation.

PURPOSE: To investigate the influence of lactation and ovarian hormones on uterine morphology and function by comparing uteruses of lactating women with nulliparous women on MRI. MATERIALS AND METHODS: Sagittal T2WI and cine MR images were obtained with 1.5 Tesla (T) and 3T scanner from 22 lactating women and 16 nulliparous women as a control group. The lactating group was further divided into amenorrhea and menorrhea subgroups. Uterine area, endometrial thickness, junctional zone (JZ) thickness, relative signal intensity (rSI) of the JZ, and of the outer myometrium (OM), were measured on T2-weighted fast spin echo images as static image parameters. Frequency of peristalsis (/3min), degree of endometrial transformation, subendometrial conduction, outer myometrial (OM) conduction, and sporadic myometrial contraction were evaluated using cine MR images. The above image parameters were compared between the lactating group and the control group, and between the lactational amenorrhea group and the lactational menorrhea group as a sub-analysis. RESULTS: A significant difference was observed in all the static image parameters and in three of the five cine image parameters between the lactating group and the control group (P < 0.01). In sub-analysis, a statistical significance was found between the lactational amenorrhea group and lactational menorrhea group in area of the uterus and both endometrial and JZ thickness (P < 0.05), but not in cine image parameters (P = 0.682, P = 0.096, P = 0.191, P = 0.939, P = 0.289, respectively). CONCLUSION: Uterine appearance and peristalsis were different between lactating and nulliparous women. The morphological differences were pronounced between lactating amenorrhea and menorrhea women. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:617-623.