The implementation of artificial intelligence to the low-cost metaphase finder.

Biological dosimetry is used to estimate one's dose by biological phenomena. The most popular and 'gold standard' phenomenon is the appearance of dicentric chromosomes in metaphases. The metaphase finder is a tool for biological dosimetry that finds metaphase cells on glass slides. It consists of an automated microscope, auto-focus system, X-Y stage, camera and computer. It does the image analysis of the microscopic images of the glass slides and displays the positions of metaphase cells. In this paper, the author reported that the prototype of AI-implemented metaphase finder was combined with the microscope system by file sharing and image transfer program, and that the metaphase finder system's accuracy was compared with previous non-AI system, using the same samples.

Gastrointestinal stromal tumors: a comprehensive radiological review.

Gastrointestinal stromal tumors (GISTs) originating from the interstitial cells of Cajal in the muscularis propria are the most common mesenchymal tumor of the gastrointestinal tract. Multiple modalities, including computed tomography (CT), magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography, ultrasonography, digital subtraction angiography, and endoscopy, have been performed to evaluate GISTs. CT is most frequently used for diagnosis, staging, surveillance, and response monitoring during molecularly targeted therapy in clinical practice. The diagnosis of GISTs is sometimes challenging because of the diverse imaging findings, such as anatomical location (esophagus, stomach, duodenum, small bowel, colorectum, appendix, and peritoneum), growth pattern, and enhancement pattern as well as the presence of necrosis, calcification, ulceration, early venous return, and metastasis. Imaging findings of GISTs treated with antineoplastic agents are quite different from those of other neoplasms (e.g. adenocarcinomas) because only subtle changes in size are seen even in responsive lesions. Furthermore, the recurrence pattern of GISTs is different from that of other neoplasms. This review discusses the advantages and disadvantages of each imaging modality, describes imaging findings obtained before and after treatment, presents a few cases of complicated GISTs, and discusses recent investigations performed using CT and MRI to predict histological risk grade, gene mutations, and patient outcomes.

MTL-ABS3Net: Atlas-Based Semi-Supervised Organ Segmentation Network With Multi-Task Learning for Medical Images.

Organ segmentation is one of the most important step for various medical image analysis tasks. Recently, semi-supervised learning (SSL) has attracted much attentions by reducing labeling cost. However, most of the existing SSLs neglected the prior shape and position information specialized in the medical images, leading to unsatisfactory localization and non-smooth of objects. In this paper, we propose a novel atlas-based semi-supervised segmentation network with multi-task learning for medical organs, named MTL-ABS3Net, which incorporates the anatomical priors and makes full use of unlabeled data in a self-training and multi-task learning manner. The MTL-ABS3Net consists of two components: an Atlas-Based Semi-Supervised Segmentation Network (ABS3Net) and Reconstruction-Assisted Module (RAM). Specifically, the ABS3Net improves the existing SSLs by utilizing atlas prior, which generates credible pseudo labels in a self-training manner; while the RAM further assists the segmentation network by capturing the anatomical structures from the original images in a multi-task learning manner. Better reconstruction quality is achieved by using MS-SSIM loss function, which further improves the segmentation accuracy. Experimental results from the liver and spleen datasets demonstrated that the performance of our method was significantly improved compared to existing state-of-the-art methods.

Measurements and future projections of Gd-based contrast agents for MRI exams in wastewater treatment plants in the Tokyo metropolitan area.

Large amounts of Gd-based contrast agents are used in magnetic resonance imaging (MRI) that are then excreted in urine. These agents are subsequently discharged into the environment because they are difficult to remove by usual sewage treatment techniques. In this study, changes of the Gd anomaly during wastewater treatment processes were determined by analyzing wastewater samples and the possibility for future prediction of the changes was evaluated based on the relationship between the Gd anomaly and the number of MRI devices in use. After the wastewater treatment processes, the values of final effluent were increased 1.8 times compared to those of influent, and the Gd anomaly of effluent had a positive correlation to the number of MRI devices. The finding suggested that the changes of environmental impact were predictable based on the number of MRI devices.

An Efficient and Accurate 3D Multiple-Contextual Semantic Segmentation Network for Medical Volumetric Images.

Convolutional neural networks have become popular in medical image segmentation, and one of their most notable achievements is their ability to learn discriminative features using large labeled datasets. Two-dimensional (2D) networks are accustomed to extracting multiscale features with deep convolutional neural network extractors, i.e., ResNet-101. However, 2D networks are inefficient in extracting spatial features from volumetric images. Although most of the 2D segmentation networks can be extended to three-dimensional (3D) networks, extended 3D methods are resource and time intensive. In this paper, we propose an efficient and accurate network for fully automatic 3D segmentation. We designed a 3D multiple-contextual extractor (MCE) to simulate multiscale feature extraction and feature fusion to capture rich global contextual dependencies from different feature levels. We also designed a light 3D ResU-Net for efficient volumetric image segmentation. The proposed multiple-contextual extractor and light 3D ResU-Net constituted a complete segmentation network. By feeding the multiple-contextual features to the light 3D ResU-Net, we realized 3D medical image segmentation with high efficiency and accuracy. To validate the 3D segmentation performance of our proposed method, we evaluated the proposed network in the context of semantic segmentation on a private spleen dataset and public liver dataset. The spleen dataset contains 50 patients' CT scans, and the liver dataset contains 131 patients' CT scans.

Transverse Viscous Transport in Classical Solid States.

The transverse velocity time correlation function C[over ˜]_{T}(k,ω) with k and ω being the wave number and the frequency, respectively, is a fundamental quantity in determining the transverse mechanical and transport properties of materials. In ordinary liquids, a nonzero value of C[over ˜]_{T}(k,0) is inevitably linked to viscous material flows. Even in solids where significant material flows are precluded due to almost frozen positional degrees of freedom, our molecular dynamics simulations reveal that C[over ˜]_{T}(k,0) takes a nonzero value, whereby the time integration of the velocity field shows definite diffusive behavior with diffusivity C[over ˜]_{T}(k,0)/3. This behavior is attributed to viscous transport accompanying a small random convection of the velocity field (the inertia effect), and the resultant viscosity is measurable in the Eulerian description: the constituent particles that substantially carry momenta fluctuate slightly around their reference positions. In the Eulerian description, the velocity field is explicitly associated with such fluctuating instantaneous particle positions, whereas in the Lagrangian description, this is not the case. The present study poses a fundamental problem for continuum mechanics: reconciling liquid and solid descriptions in the limit of the infinite structural relaxation time.

Silicate/zinc-substituted strontium apatite coating improves the osteoinductive properties of ß-tricalcium phosphate bone graft substitute.

BACKGROUND: ß-Tricalcium phosphate (ß-TCP) is a popular synthetic bone graft substitute with excellent osteoconductive properties and bioabsorbability. However, its osteoinductive properties are inferior to those of autologous or allogeneic bone. Trace elements such as strontium (Sr), silica (Si), and zinc (Zn) have been reported to promote osteogenesis in materials. In this study, we aimed to determine whether a Si/Zn-substituted Sr apatite coating of ß-TCP could enhance osteoinductive properties. METHODS: The apatite-coated ß-TCP disks were prepared using nanoparticle suspensions of silicate-substituted Sr apatite (SrSiP) or silicate- and Zn-co-substituted Sr apatite (SrZnSiP). Bone marrow mesenchymal cells (BMSCs) from rat femur were cultured and subsequently seeded at a density of 1.0 × 106/cm2 onto apatite-coated and non-coated ß-TCP disks. In vitro, the ß-TCP disks were then placed in osteogenic medium, and lactate dehydrogenase (LDH) activity was measured from supernatants after culture for 2 days. Additionally, after culture for 14 days, the mRNA expression of genes encoding osteocalcin (OC), alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was evaluated by qRT-PCR. In vivo, the ß-TCP disks were transplanted subcutaneously into rats that were sacrificed after 4 weeks. Then, the harvested disks were evaluated biochemically (ALP activity, OC content, mRNA expression of OC, ALP, BMP-2, and VEGF measured by qRT-PCR), radiologically, and histologically. RESULTS: Significantly higher mRNA expression of almost all evaluated osteogenic and angiogenic genes was observed in the SrZnSiP and SrSiP groups than in the non-coated group, with no significant cytotoxicity elicited by the apatite coating in vitro. Moreover, in vivo, the SrZnSiP and SrSiP groups showed significantly higher osteogenic and angiogenic gene expression and higher ALP activity and OC content than the non-coated group (P < 0.05). Radiological and histopathological findings revealed abundant bone formation in the apatite-coated group. CONCLUSIONS: Our findings indicate that apatite coating of ß-TCP improves osteoinductive properties without inducing significant cytotoxicity.

Maladaptive coping, victimization, and recidivism among Japanese adolescents and emerging adults.

BACKGROUND: Substance use and victimization are known to be related to juvenile recidivism. Self-harm, a factor that commonly accompanies substance use and victimization, is not known to be related to said recidivism but may be so in a welfare-oriented juvenile justice system as found in Japan. OBJECTIVE: We examine the extent to which maladaptive coping, comprising substance use and self-harm, increases the rate of persistence in correctional institutions in light of other well-replicated factors of youth recidivism. The study, too, investigates the role of maladaptive coping in explaining the impact of victimization on correctional recidivism. METHODS: We draw from a sample of 348 adolescents and emerging adults, between ages 12-19 years, who were initially detained at a Juvenile Classification Home and followed-up for an average of 3.35 years. RESULTS: Findings indicate that maladaptive coping is significantly related to persistence in the system, although history of probationary supervision and gang membership also were significant explanatory factors. In addition, the direct effect of victimization was larger than the indirect effect of victimization through maladaptive coping. CONCLUSIONS: Unlike previous studies, self-harm is significantly related to recidivism. This suggests that recidivism reflects a need for help more so than for punishment. The wider implications are that juvenile justice systems characterized as punitive seem outdated in managing detained young people as they lack adequate prevention supports.

Noncontrast MRI of acute abdominal pain caused by gastrointestinal lesions: indications, protocol, and image interpretation.

Gastrointestinal tract lesions are major causes of acute abdominal pain. A rapid, accurate, and reliable diagnosis is required to manage patients. Magnetic resonance imaging (MRI) is a nonionizing modality that is beneficial for pregnant women, children, and young adults who are sensitive to ionizing radiation. For patients with renal impairment who are not accurately diagnosed with noncontrast computed tomography, noncontrast MRI can serve as an alternative diagnostic modality. MRI protocols used for acute abdominal pain are supposed to be optimized and prioritized to shorten scanning times. Single-shot T2-weighted and fat-suppressed T2-weighted imaging are important pulse sequences that are used to reveal pathology and inflammation in the gastrointestinal tract. Diffusion-weighted imaging clearly depicts inflammation and abscesses as hyperintense lesions. Most acute gastrointestinal tract lesions, including inflammation, ischemia, obstruction, and perforation, demonstrate bowel wall thickening. Bowel obstruction and adynamic ileus present bowel dilatation, and perforation and penetration show bowel wall defects. MRI can be used to reveal these pathological findings with some characteristics depending on their underlying pathophysiology. This review article discusses imaging modalities for acute abdominal pain, describes a noncontrast MRI protocol for acute abdominal pain caused by gastrointestinal tract lesions, and reviews MRI findings of acute gastrointestinal tract lesions.

Negative density-dependence of the structural relaxation time of liquid silica: insights from a comparative molecular dynamics study.

In many tetrahedral network-forming liquids, structural relaxation is anomalously accelerated by compression over relatively low pressure ranges. Here, for silica, we study this problem through comparative molecular dynamics simulations using two different models. Under compression, the network structures are compacted by slight tuning of the intertetrahedral bond angles while nearly preserving the unit tetrahedral structure. The consequent structural changes are remarkable for length scales larger than the nearest neighbor ion-pair distances. Accompanying with such structural changes, the interactions of the nearest Si-O pairs remain almost unchanged, whereas those of other ion pairs are, on average, strengthened by the degree of compression. In particular, the enhancement of the net Si-O interactions at the next nearest neighbor distance, which assist an ion in escaping from the potential well, reduces the activation energy, leading to a significant acceleration of structural relaxation. The results of our comparative molecular dynamics simulations are compatible with the scenario proposed by Angell, and further indicate that the structural relaxation dynamics cannot be uniquely determined by the configurations but strongly depends on the details of the coupling between the structure and the interaction.

In vitro osteogenesis of rat bone marrow mesenchymal cells on PEEK disks with heat-fixed apatite by CO2 laser bonding.

BACKGROUND: Polyether-ether-ketone (PEEK) is increasingly being used for spinal applications. However, because of its biologically inactive nature, there are risks of false joint loosening and sinking. PEEK materials are coated with apatite to enhance the osteoconductive properties. In this study, we aimed to evaluate whether strontium apatite stimulate osteogenesis on the surface of PEEK by using the CO2 laser technique. METHODS: We prepared non-coated disks, laser-exposed disks without apatite, and four types of apatite-coated by laser PEEK disks (hydroxyapatite (HAP), strontium hydroxyapatite (SrHAP), silicate-substituted strontium apatite (SrSiP), and silicate-zinc-substituted strontium apatite (SrZnSiP)). A part of the study objective was testing various types of apatite coatings. Bone marrow mesenchymal cells (BMSCs) of rats were seeded at a density of 2 × 104/cm2 onto each apatite-coated, non-coated, and laser-irradiated PEEK disks. The disks were then placed in osteogenic medium, and alkaline phosphatase (ALP) staining and Alizarin red staining of BMSCs grown on PEEK disks were performed after 14 days of culture. The concentrations of osteocalcin (OC) and calcium in the culture medium were measured on days 8 and 14 of cell culture. Furthermore, mRNA expression of osteocalcin, ALP, runt-related transcription factor 2 (Runx2), collagen type 1a1 (Col1a1), and collagen type 4a1 (Col4a1) was evaluated by qPCR. RESULTS: The staining for ALP and Alizarin red S was more strongly positive on the apatite-coated PEEK disks compared to that on non-coated or laser-exposed without coating PEEK disks. The concentration of osteocalcin secreted into the medium was also significantly higher in case of the SrHAP, SrSiP, and SrZnSiP disks than that in the case of the non-coated on day14. The calcium concentration in the PEEK disk was significantly lower in all apatite-coated disks than that in the pure PEEK disks on day 14. In qPCR, OC and ALP mRNA expression was significantly higher in the SrZnSiP disks than that in the pure PEEK disks. CONCLUSIONS: Our findings demonstrate that laser bonding of apatite-along with trace elements-on the PEEK disk surfaces might provide the material with surface property that enable better osteogenesis.

Optimization of pulse sequences in ultrafast magnetic resonance imaging for the diagnosis of acute abdominal pain caused by gastrointestinal disease.

BACKGROUND: Magnetic resonance imaging (MRI) is widely used to diagnose acute abdominal pain; however, it remains unclear which pulse sequence has priority in acute abdominal pain. PURPOSE: To investigate the diagnostic accuracy of MRI and to assess the conspicuity of each pulse sequence for the diagnosis of acute abdominal pain due to gastrointestinal diseases. MATERIAL AND METHODS: We retrospectively enrolled 60 patients with acute abdominal pain who underwent MRI for axial and coronal T2-weighted (T2W) imaging, fat-suppressed (FS)-T2W imaging, and true-fast imaging with steady-state precession (True-FISP) and axial T1-weighted (T1W) imaging and investigated the diagnosis with endoscopy, surgery, histopathology, computed tomography, and clinical follow-up as standard references. Two radiologists determined the diagnosis with MRI and rated scores of the respective sequences in assessing intraluminal, intramural, and extramural abnormality using a 5-point scale after one month. Diagnostic accuracy was calculated and scores were compared by Wilcoxon-signed rank test with Bonferroni correction. RESULTS: Diagnostic accuracy was 90.0% and 93.3% for readers 1 and 2, respectively. Regarding intraluminal abnormality, T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in both readers. FS-T2W imaging was superior to True-FISP in reader 2 (P < 0.0083). For intramural findings, there was no significant difference in reader 1, whereas T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in reader 2 (P < 0.0083). For extramural findings, FS-T2W imaging was superior to T2W, T1W, and True-FISP imaging in both readers (P < 0.0083). CONCLUSION: T2W and FS-T2W imaging are pivotal pulse sequences and should be obtained before T1W and True-FISP imaging.

Foreign-body granulomas and abscesses caused by dropped gallstones after cholecystectomy: Four cases diagnosed with multimodality imaging.

Four cases (age range, 60-78 years, male:female = 1:3) who had undergone cholecystectomy presented with fever (n = 1), right abdominal pain with fever (n = 1), appetite loss with fever (n = 1), and absence of symptoms (n = 1). Computed tomography (CT) showed an irregular-shaped invasive mass or fluid collection in the right Morrison's pouch, right paracolic gutter, gallbladder fossa, subphrenic space, or abdominal wall. CT and ultrasound revealed gallstones in the granuloma in 3 cases and an abscess in one case. The inflammatory process induced by dropped gallstones may mimic peritoneal malignancies. Awareness of cholecystectomy and the detection of gallstones in the lesion are essential for the diagnosis of dropped gallstones.

Prognostic Factors of Preoperative Examinations for Non-occlusive Mesenteric Ischemia: A Multicenter Retrospective Project Study Conducted by the Japanese Society for Abdominal Emergency Medicine.

BACKGROUND: Non-occlusive mesenteric ischemia (NOMI) has a high mortality rate, but the analyses of preoperative prognostic factors for improving survival in patients suspected of having NOMI are scarce. We aimed to analyze the prognostic factors of preoperative examinations for NOMI. METHODS: The clinical data of 224 patients with NOMI were retrospectively collected for a multicenter survey. Clinicophysiological factors were compared between the survivors and non-survivors (N = 107/117) and between the operative and non-operative cases (N = 180/44) by univariate analysis using chi-square test and multivariate analysis using Cox proportional hazard models. In the operative cases, the prognostic operative factors were also analyzed. RESULTS: The overall mortality rate for NOMI was 52.2%. There were 129 male and 95 female patients. The mean age was 71.23 (14-94) years. Univariate analysis showed that cardiovascular complication, shock, abdominal pain, average blood pressure, systemic inflammatory response syndrome, aspartic aminotransferase, alanine transaminase, creatine phosphokinase, lactate dehydrogenase, base excess, prothrombin time-international normalized ratio, D-dimer, and fibrinogen degradation products were independent prognostic factors. Multivariate analysis showed that average blood pressure and base excess were independent prognostic factors. Among patients undergoing surgery, those with bowel resection had better prognosis than those without bowel resection, but those with long bowel resection had worse prognosis than those with short resection. Additional postoperative treatment was not effective compared with operation alone (P = 0.011). CONCLUSIONS: Prognostic factors of preoperative examinations for NOMI were average blood pressure and base excess. Patients with long bowel resection should be carefully monitored owing to their poor prognosis.

Impact on gadolinium anomaly in river waters in Tokyo related to the increased number of MRI devices in use.

The Gd-based contrast agents utilized in magnetic resonance imaging are difficult to remove by usual sewage treatment technology, and they enter rivers in the discharges from waste water treatment plants. Gd anomaly in rivers has been considered depends on used amount of Gd-based contrast agents. In this study, variation of Gd anomaly in rivers of Tokyo was determined by comparisons to previously reported values. The range of anthropogenic Gd was 0.1-138.8 ppt with an average value of 35.5 ppt (n = 40); in particular, the anthropogenic Gd was significantly changed depending on the location of the waste water treatment plants, and the measurement revealed significant increases in the Gd anomaly in the range of 5.0-6.6 times compared to data obtained 22 years ago. This study highlights the necessary of continuous research in setting new public policies for medical practices.

Social contribution of forensic odontology in Japan.

Half a century has passed since the department for education and research on forensic odontology was established at dentistry-related universities in Japan in 1964. In order to meet the demands of society, the number of universities with a department of forensic odontology increased up until around 2005. In 2007, the Japanese Society of Forensic Dental Science was established, and then a series of reforms such as establishment of the Study Council on Death Cause Investigation in both the National Police Agency and the Cabinet Office of the Japanese government, cabinet decision of enactment and enforcement of new laws on death cause investigation, publication of an article on the Model Core Curriculum of Dental Education, publication of the results of a fact-finding survey on education and research on forensic odontology conducted by the Ministry of Education, Culture, Sports, Science and Technology, inclusion of questions about forensic odontology in the National Board Dental Examination, and compilation of a database on dental findings by the Ministry of Health, Labor and Welfare, proceeded in succession. We introduced the half century of forensic odontology in Japan in chronological order.

Complex dynamical interplay between solid particles and flow in driven granular suspensions.

Granular materials immersed in a fluid are ubiquitous in daily life, industry, and nature. They include food processing, pastes, cosmetics, paints, concretes, cements, muds, wet sands, snows, landslides, and lava flow. They are known to exhibit a rich variety of complex rheological behavior, but the role of a fluid component in such behavior has remained poorly understood due to the nonlocal and many-body nature of hydrodynamic interactions between solid particles mediated by the fluid. We address this fundamental problem by comparing the microrheological response of athermal granular suspensions with and without hydrodynamic interactions to an externally driven probe particle by numerical simulations. We find that the presence of the fluid drastically increases the drag coefficient of the probe particle by more than one order of magnitude near the jamming transition. We reveal that this is a consequence of the nontrivial long-range nature of hydrodynamic interactions, which originates from unlimited cumulative transmission of near-field hydrodynamic interactions due to the incompressibility of both fluid and solid particles. Force chain formation of solid particles is dynamically coupled with hydrodynamic flow, leading to strong spatiotemporal fluctuations of flow pattern and nonlinear rheological response. Our study reveals essential roles of hydrodynamic interactions in complex rheological behavior of dense granular suspensions under an external drive.

Silicate-substituted strontium apatite nano coating improves osteogenesis around artificial ligament.

BACKGROUND: Treatment of anterior cruciate ligament injuries commonly involves the use of polyethylene terephthalate (PET) artificial ligaments for reconstruction. However, the currently available methods require long fixation periods, thereby necessitating the development of alternative methods to accelerate the healing process between tendons and bones. Thus, we developed and evaluated a novel technique that utilizes silicate-substituted strontium (SrSiP). METHODS: PET films, nano-coated with SrSiP, were prepared. Bone marrow mesenchymal cells (BMSCs) from femurs of male rats were cultured and seeded at a density of 1.0 × 104/cm2 onto the SrSiP-coated and non-coated PET film, and subsequently placed in an osteogenic medium. The osteocalcin concentration secreted into the medium was compared in each case. Next, PET artificial ligament, nano-coated with SrSiP, were prepared. BMSCs were seeded at a density of 4.5 × 105/cm2 onto the SrSiP-coated, and non-coated artificial ligament, and then placed in osteogenic medium. The osteocalcin and calcium concentrations in the culture medium were measured on the 8th, 10th, 12th, and 14th day of culture. Furthermore, mRNA expression of osteocalcin, alkaline phosphatase (ALP), bone morphogenetic protein-2 (BMP2), and runt-related transcription factor 2 (Runx2) was evaluated by qPCR. We transplanted the SrSiP-coated and non-coated artificial ligament to the tibiae of mature New Zealand white rabbits. Two months later, we sacrificed them and histologically evaluated them. RESULTS: The secretory osteocalcin concentration in the medium on the film was significantly higher for the SrSiP group than for the non-coated group. Secretory osteocalcin concentration in the medium on the artificial ligament was also significantly higher in the SrSiP group than in the non-coated group on the 14th day. Calcium concentration on the artificial ligament was significantly lower in the SrSiP group than in the non-coated group on the 8th, 10th, 12th, and 14th day. In qPCR as well, OC, ALP, BMP2, and Runx2 mRNA expression were significantly higher in the SrSiP group than in the non-coated group. Newly formed bone was histologically found around the artificial ligament in the SrSiP group. CONCLUSIONS: Our findings demonstrate that artificial ligaments using SrSiP display high osteogenic potential and thus may be efficiently used in future clinical applications.

Accuracy, criteria, and clinical significance of visual assessment on diffusion-weighted imaging and apparent diffusion coefficient quantification for diagnosing acute appendicitis.

PURPOSE: To assess the accuracy, criteria, and clinical significance of diffusion-weighted imaging (DWI) signal intensity and apparent diffusion coefficient (ADC) quantification for diagnosing acute appendicitis. METHODS: Fifty-one patients with right lower abdominal pain [uncomplicated appendicitis (n = 25), complicated appendicitis (n = 10), and non-appendicitis (n = 16)] who underwent MR examination were enrolled in this retrospective study. Two radiologists independently measured appendiceal diameter and wall thickness. They assessed whether a wall defect, an abscess, extraluminal air, or an appendicolith was present on axial T2WI; evaluated intensity on DWI using a 5-point scale; and determined the ADC values of the appendix and peri-appendiceal tissue. Statistical analysis was performed to assess imaging findings for the diagnosis of appendicitis and complicated appendicitis. Cut-off values were determined using receiver operating characteristic analysis. RESULTS: For diagnosing acute appendicitis, the accuracy improved from 78.4% using only T2WI to 86.3% using combined T2WI and DWI for reader 1 and from 82.4 to 86.3% for reader 2. For the appendix, the cut-off ADC values that diagnosed appendicitis were 1.41 × 10-3 and 1.26 × 10-3 mm2/s with accuracies of 78.4% and 76.5%, respectively. For the peri-appendiceal tissue, these values of 1.03 × 10-3 and 0.91 × 10-3 mm2/s differentiated between uncomplicated and complicated appendicitis with an accuracy of 97.1%. CONCLUSIONS: Combined DWI and T2WI provided high accuracy for diagnosing appendicitis. The inflamed appendix had lower ADC value than the normal appendix. The peri-appendiceal tissue presenting low ADC value was a notable finding of complicated appendicitis.