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OBJECTIVE The objective of this study was to evaluate the clinical feasibility of high-resolution contrast-enhanced dynamic T1-weighted imaging (T1WI) using compressed sensing (CS) in magnetic resonance imaging. METHODS This study retrospectively included 35 patients who underwent dynamic T1WI using volumetric interpolated breath-hold examination (VIBE) with CS reconstruction (CS-VIBE) and 35 patients with conventional VIBE for comparison. Two observers assessed the liver and pancreas edges, hepatic artery, motion artifacts, and overall image quality. Quantitative analysis was performed by measuring signal intensity and image noise. RESULTS The results showed that CS-VIBE achieved significantly better anatomic delineation of the liver and pancreas edges and hepatic artery clarity than VIBE (P < 0.001). There were no significant differences in motion artifacts in dynamic phases and overall image quality. The signal intensities and INs of CS-VIBE were higher than VIBE. CONCLUSIONS High-resolution dynamic T1WI using CS provides better anatomic delineation with comparable or better overall image quality than conventional VIBE.

The objective of this study was to compare the image quality and apparent diffusion coefficient (ADC) of diffusion-weighted imaging (DWI) with modified reduced field of view (FOV) based on 2-dimensional (2D)-selective radiofrequency excitations by tilting the excitation plane in prostate with reduced FOV using parallel-transmit-accelerated 2D-selective radiofrequency excitation and single-shot echo planar imaging (ssEPI).Fifty patients who underwent multiparametric magnetic resonance imaging including 3 DWIs were included. Two observers independently performed qualitative image analyses using 5-point scale. Apparent diffusion coefficient measurements were performed for quantitative analysis.Modified reduced FOV provided the highest qualitative scores for all categories compared with reduced FOV and ssEPI (P0.000). Both reduced FOV DWIs showed higher ADC values compared with ssEPI (P0.001); however, the ADC ratios between the lesion and peripheral zone were not significantly different (all P0.05).The modified reduced FOV DWI showed better overall image quality, differentiability of anatomic regions, and lesion conspicuity with fewer artifacts compared with DWI with reduced FOV and ssEPI.

SUMMARY Hemorrhagic pseudocysts with pseudoaneurysms are a rare and fatal complication of chronic pancreatitis due to the erosion of pancreatic to peripancreatic arteries. The timing of the rupture cannot be accurately predicted, but prompt diagnosis and management are essential to prevent further bleeding. We describe the case of a 68-year-old man who presented acute epigastric pain and anemia and had a history of chronic pancreatitis with a pseudocyst. A biliary and pancreas MRI showed an enlarged size of a known pancreatic pseudocyst with internal high signal intensity material. Color-Doppler ultrasonography showed pulsating signals in the pseudocyst, and our final diagnosis was a pseudoaneurysm in the pancreatic hemorrhagic pseudocyst. The pseudoaneurysm was successfully treated with coil embolization of the feeding artery. We report this case of a rare complication of chronic pancreatitis to show that color-Doppler ultrasound is a non-invasive and effective diagnostic tool for pseudoaneurysm, which enables early detection and prompt treatment without the need for invasive diagnostic modalities.

Objective To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and methods This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

Colon cancer arising in a colonic diverticulum is very rare. There are only a few reported cases of colon cancer associated with a diverticulum. Of these reported cases, only a few are those of a mucinous adenocarcinoma. Here, we report a case of an 82-year-old female with a mucinous adenocarcinoma arising in the ascending colonic diverticulum, which clinically and radiologically mimicked perforated diverticulitis with abscess formation. Although such cases are rare, our findings suggest that malignant tumors may be misdiagnosed as diverticular diseases and should be considered during work-up.

Summary Background CT radiation is arguably carcinogenic. Results from single-centre studies, mostly retrospective, have advocated lowering the CT radiation dose for the diagnosis of appendicitis. However, adoption of low-dose CT has been slow. We aimed to assess the effectiveness of low-dose CT compared with standard-dose CT in the diagnosis of appendicitis in adolescents and young adults. Methods We did this pragmatic, multicentre, randomi s ed controlled non-inferiority trial at 20 South Korean teaching hospitals with little experience with low-dose CT. Patients aged 15–44 years with suspected appendicitis were randomly assigned (1:1), via computer-generated random assignments (permuted block sizes of two, four, six, and eight) concealed in sequentially numbered envelopes, to receive low-dose CT (2 mSv) or standard-dose CT (≤8 mSv). Randomisation was stratified by site. Group allocation was concealed from patients, outcome assessors, and adverse event adjudicators; care providers, site pathologists, and data collectors were aware of allocation. The primary endpoint was the negative (unnecessary) appendectomy rate among all appendectomies, with a non-interiority margin of 4·5% for low-dose versus standard-dose CT. Primary analy s is was by modified intention to treat, which included all patients who received an appendectomy in the group to which they were assigned. This trial is registered with ClinicalTrials.gov, number NCT01925014. Findings Between Dec 4, 2013, and Aug 18, 2016, we assigned 1535 patients to the low-dose CT group and 1539 patients to the standard-dose CT group. 22 (3·9%) of 559 patients had a negative appendectomy in the low-dose group versus 16 (2·7%) of 601 patients in the standard-dose group (difference 1·3%, 95% CI −0·8 to 3·3; p=0·0022 for the non-inferiority test). We recorded 43 adverse events in 43 (2·8%) of 1535 patients in the low-dose group and 41 adverse events in 40 (2·6%) of 1539 patients in the standard-dose group. One life-threatening adverse event of anaphylaxis caused by an iodinated contrast material occurred in the low-dose group. Interpretation Radiation dose of appendiceal CT for adolescents and young adults can be reduced to 2 mSv without impairing clinical outcomes. In view of the vast number of appendiceal CT examinations done worldwide, use of low-dose CT could prevent a sizeable number of radiation-associated cancers in the future. Funding Korea Health Industry Development Institute, Seoul National University Bundang Hospital, Dasol Life Science, and Bracco Imaging Korea.

To compare diagnostic performance of magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS) for differentiating malignant from benign intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) of the pancreas. This retrospective study included 55 patients with 47 surgically confirmed IPMNs (12 malignant, 35 benign) and eight MCNs (two malignant, six benign) who underwent contrast-enhanced pancreas MRI and EUS. Contrast enhancement was not routinely used at EUS examination. Two observers independently evaluated the MRIs, and another reviewed EUS images. They recorded their confidence for malignancy with each imaging modality. We calculated diagnostic performance using the area under the receiver operating characteristic curves (A z ), and to determine the accuracy, sensitivity, specificity, and positive (PPV) and negative predictive (NPV) values. The A z values of MRI were higher than those of EUS (0.712 and 0.688 for MRI vs. 0.543 for EUS; p = 0.007). The diagnostic accuracies (74.5%), specificity (78.0% and 80.5%) and PPV (50.0%) of MRI in two observers were higher than those (56.4%, 58.5% and 29.2%, respectively) of EUS (p = 0.013–0.049). MRI showed better diagnostic performance than EUS for differentiating malignant from benign pancreatic IPMN and MCN. • The A z values of MRI were higher than those of EUS. • The diagnostic accuracies of MRI were higher than those of EUS. • The specificities of MRI were higher than those of EUS.

We report a rare case of barium peritonitis following an upper gastrointestinal (GI) series and its imaging findings in a 74-year-old female. Barium peritonitis is a rare but life-threatening complication of GI contrast investigation. Therefore, clinical awareness of barium peritonitis as a complication of GI tract contrast investigation would help to prevent such a complication and manage the patients properly.

SUMMARY OBJECTIVE: To determine the computed tomography (CT) signs associated with stercoral perforation and colorectal cancer perforation. MATERIALS AND METHODS: From May 2003 to Feb. 2015, all surgically and pathologically confirmed patients with stercoral perforation (n=8, mean age 68.3 years) or colon cancer perforation (n=11, mean age 66.3 years) were retrospectively reviewed by two board-certified radiologists blinded to the proven diagnosis. The following CT findings were evaluated and recorded for each patient: wall thickness of the distal colon adjacent to perforation site, pattern of the colon wall thickening and enhancement, length of the thickened bowel wall, presence of fecaloma, degree of proximal colon dilatation, and pericolonic inflammation or presence of pericolonic abscess, and number of enlarged pericolonic lymph nodes. These findings were correlated with the pathologic diagnosis. RESULTS: The mean thickness of the distal colonic wall adjacent to the perforation site was 13.6 mm in patients with colorectal cancer perforation and 5.1 mm with stercoral perforation, which was statistically different. There was a significant correlation between colorectal cancer perforation and eccentric wall thickening (p

Purpose To compare image quality and the effect of radiation dose reduction after decreasing tube voltage from 120 kVp to 100 kVp for abdominal CT in adults. Materials and Methods A total of 200 patients who underwent abdominal CT at 120 kVp (n = 100) or 100 kVp (n = 100) were enrolled. Automatic tube current modulation was applied with other scan parameters being constant. Radiation dose was calculated based on CT dosimetry index. The image quality of abdominal organs and image noise were assessed quantitatively and qualitatively. Results A radiation dose reduction of 13.3% was found in the 100 kVp group. On quantitative analysis, image noise was increased up to 47% in the 100 kVp group. CT numbers of liver, pancreas, renal cortex, aorta, portal vein, and psoas muscle in the 100 kVp group were significantly (p < 0.05) higher than those in the 120 kVp group. Signal-to-noise ratio was significantly higher (p < 0.05) in the 120 kVp group. Contrast-to-noise ratio (CNR) of the liver was higher in the 120 kVp group. However, no significant (p > 0.05) difference was observed in the CNR of other organs between the two groups. On qualitative analysis, noise texture of abdominal organs, artifact, and diagnostic acceptability were not significantly (p > 0.05) different. Conclusion 100 kVp abdominal CT reduced radiation dose by 13.3% without sacrificing image quality compared to 120 kVp abdominal CT.

Meckel's diverticulum is the most frequent congenital malformation of the gastrointestinal tract, occurring in 2% of the general population. Meckel's diverticulum is usually asymptomatic and found incidentally. However, the lifetime risk of complications is 4-40%. In this essay, we describe the clinical and imaging findings in 12 cases of Meckel's diverticula with complications over a 5-year period, which were confirmed pathologically. The major complications of Meckel's diverticulum include gastrointestinal bleeding, bowel obstruction, perforation and inflammation. Small bowel follow-through (SBFT), computed tomography (CT) including CT enterography and RI scintigraphy can be used to show typical imaging features of Meckel's diverticulum and its complications. Knowledge of the clinical and radiologic findings of Meckel's diverticulum can aid in the early and accurate diagnosis of this anomaly and its complications.

SUMMARY OBJECTIVE: To assess the diagnostic performance of CT findings in differentiating causes of pneumatosis intestinalis (PI), including benign and life-threatening causes. METHODS: All CT reports containing the word “pneumatosis” were queried from June 1st, 2006 to May 31st, 2015. A total of 42 patients with PI were enrolled (mean age, 63.4 years; 23 males and 19 females) and divided into two groups on based on electronic medical records: a benign group (n=24) and a life-threatening group (n=18). Two radiologists reviewed CT images and evaluated CT findings including bowel distension, the pattern of bowel wall enhancement, bowel wall defect, portal venous gas (PVG), mesenteric venous gas (MVG), extraluminal free air, and ascites. RESULTS: CT findings including bowel distension, decreased bowel wall enhancement, PVG, and ascites were more commonly identified in the life-threatening group (all p

Pediatric breast disease is uncommon, and primary breast carcinoma in children is extremely rare. Therefore, the approach used to address breast lesions in pediatric patients differs from that in adults in many ways. Knowledge of the normal imaging features at various stages of development and the characteristics of breast disease in the pediatric population can help the radiologist to make confident diagnoses and manage patients appropriately. Most breast diseases in children are benign or associated with breast development, suggesting a need for conservative treatment. Interventional procedures might affect the developing breast and are only indicated in a limited number of cases. Histologic examination should be performed in pediatric patients, taking into account the size of the lesion and clinical history together with the imaging findings. A core needle biopsy is useful for accurate diagnosis and avoidance of irreparable damage in pediatric patients. Biopsy should be considered in the event of abnormal imaging findings, such as non-circumscribed margins, complex solid and cystic components, posterior acoustic shadowing, size above 3 cm, or an increase in mass size. A clinical history that includes a risk factor for malignancy, such as prior chest irradiation, known concurrent cancer not involving the breast, or family history of breast cancer, should prompt consideration of biopsy even if the lesion has a probably benign appearance on ultrasonography.

INTRODUCTION The development of dual-energy CT and metal artefact reduction software provides a further chance of reducing metal-related artefacts. However, there have been only a few studies regarding whether MARs practically affect visibility of structures around a metallic hip prosthesis on post-operative CT evaluation. METHODS Twenty-seven patients with 42 metallic hip prostheses underwent DECT. The datasets were reconstructed with 70, 90 and 110 keV with and without MARs. The areas were classified into 10 zones according to the reference zone. All the images were reviewed in terms of the severity of the beam-hardening artefacts, differentiation of the bony cortex and trabeculae and visualization of trabecular patterns with a three-point scale. The metallic screw diameter was measured in the acetabulum with 110 keV images. RESULTS The scores were the worst on 70 keV images without MARs [mean scores:1.84-4.22 (p

To determine the added value of capsule, septum, and T2 hyperintense foci for differentiating large hepatocellular carcinoma (HCC; ≥ 5 cm) from intrahepatic cholangiocarcinoma (ICC) using gadoxetic acid MRI. The study included 116 patients (94 men, 22 women; mean age, 56.8 years) with surgically confirmed HCCs (n = 87, 5.0–18.0 cm) or ICCs (n = 29, 5.0–14.0 cm) who underwent gadoxetic acid MRI. Three observers independently reviewed MRIs in two sessions, examining enhancement patterns only and then adding capsule, septum, and T2 hyperintense foci. Reviewers used a five-point scale to score accuracy, sensitivity, and specificity. A significant increase was observed in accuracy when ancillary features (96.1–98.3%) were added compared to enhancement pattern only (83.6–88.4%; p ≤ 0.02). Sensitivity was significantly increased with combined reading (97.1–98.3%) compared to enhancement features only (81.6–88.5%; p ≤ 0.006) for two observers, with no difference in specificity (84.5–89.7% vs. 86.2–98.3%; p > 0.05). We found substantial to excellent interobserver agreement for ancillary features (0.598–0.976). Adding capsule, septum, and T2 hyperintense foci to enhancement patterns for gadoxetic acid MRI increased diagnostic performance for characterizing large HCC by differentiating it from ICC. • Capsule, septum, and T2 hyperintense foci were useful for characterizing large HCC. • Adding ancillary features to enhancement pattern increased accuracy for diagnosing large HCC. • Interobserver agreement was substantial to excellent for ancillary features.

The purpose of this study is to assess the common MRI findings of acute cholangitis compared with those of non-acute cholangitis.During a 31-month period, we performed MRCP and contrast-enhanced MRI on 173 patients with biliary abnormalities including duct dilatation or stricture. The causes of the biliary abnormalities included biliary stone disease (n=85), cholangiocarcinoma (n=47), periampullary cancer (n=20), GB cancer (n=4), and others (n=17). Among 173 patients, 66 consecutive patients were confirmed with acute cholangitis diagnosed according to the Tokyo guideline, and 107 patients were confirmed as having non-acute cholangitis. Two radiologists retrospectively and independently accessed the MR findings, including the cause of biliary abnormality, increased periductal signal intensity on T2-weighted images, the transient periductal signal difference, and the presence of abscess, thrombosis, and ragged duct. They also measured the dilated duct and the thickened wall. The Student t-test and the Pearson chi-square were used. The κ statistics were used to determine interobserver agreement. Logistic regression was used to identify the MR findings that predicted acute cholangitis.MRI correctly accessed the cause of biliary abnormality in 163 patients (94%). The statistically common findings for acute cholangitis were as follows: increased periductal signal intensity on T2-weighted imaging (n=26, 39%, p0.05); transient periductal signal difference (n=31, 47%, p0.05); abscess (n=18, 27%, p0.05); thrombosis (n=12, 18%, p0.05); and ragged duct (n=11, 17%, p0.05). Interobserver agreement was good to excellent for each finding (κ=0.74-0.97). The wall thickness showed a statistically significant difference between the acute cholangitis and the non-acute cholangitis group (2.65 mm:2.32 mm, p0.05), however, there was no significant difference in duct dilatation in the two groups. The periductal transient attenuation difference was an independent predictor of acute cholangitis (Exp (B)=6.389, p=0.018).MRI accurately assesses the cause of biliary abnormality in patients with cholangitis. Using statistically common MR findings for acute cholangitis, MR imaging is very successful in predicting acute cholangitis.

To evaluate the differentiating factors for intraductal papillary mucinous neoplasm of the pancreas and chronic pancreatitis as determined by MR imaging.During a three-year period, we performed MR imaging on 33, consecutive patients with IPMN and on 41 patients with chronic pancreatitis. All IPMNs were confirmed by surgery. Two radiologists retrospectively analyzed the ductal change, the cyst shape, CBD dilatation, lymphadenopathy, and parenchymal change. The sensitivity and specificity were calculated for each MRI findings using the Chi square test. Statistically significant MR findings were further analyzed using multivariate logistic regression analysis. The diagnostic performance was evaluated according to the area under the receiver operating characteristic curve (A(z)) using specific MRI findings. Simple κ statistics were used to evaluate the inter-observer reliability.Statistically specific findings for IPMN compared with those for chronic pancreatitis, were duct dilatation without stricture (specificity=95.1%, sensitivity=75.8%, p0.0001), bulging ampulla (specificity=97.6%, sensitivity=30.3%, p0.0001), nodule in a duct (specificity=100%, sensitivity=15.2%, p0.0004), grape-like cyst shape (specificity=97.6%, sensitivity=78.8%, p0.0001), and nodule in a cyst (specificity=100%, sensitivity=24.2%, p0.0001). Statistically specific findings for chronic pancreatitis compared with those for IPMN, were duct dilatation with strictures (specificity=93.9%, sensitivity=95.1%, p0.0001), the presence of a stone (specificity=97.0%, sensitivity=56.1%, p0.0001), and a unilocular cyst shape (specificity=93.9%, sensitivity=34.1%, p0.0004). Duct dilatation without stricture and a grape-like cyst shape were independently associated with the IPMN. Duct dilatation with strictures was independently associated with the chronic pancreatitis. Interobserver agreement was good to excellent for each finding (κ=0.762-1.000).Highly specific findings for IPMN include duct dilatation without stricture, bulging ampulla, nodule in a duct, grape-like cyst shape, and nodule in a cyst. MRI is very useful for differentiating IPMN from chronic pancreatitis using these specific findings.

Metastasis from extramammary malignancy to the breast is rare, and metastasis of cervical cancer to the breast is quite uncommon. We report atypical sonographic findings of a rapid growing, single, and circumscribed mass with complex cystic and solid echo pattern in a 50-year-old female. The mass confirmed a metastasis from cervical cancer. It is rare, but the possibility of breast metastasis should be considered when a rapidly growing breast mass is located in between the parenchyma and subcutaneous fat layer.

OBJECTIVE: Diffusion-weighted imaging (DWI) with reduced field-of-view (FOV) has been shown to provide high spatial resolution with reduced distorsion in the spinal cord, breast, pancreas, and prostate gland. Therefore, we performed this study to evaluate the qualitative image quality and quantitative ADC value of reduced FOV DWI in patients with cervical cancer in comparison with conventional DWI. METHODS: This study retrospectively included 22 patients (mean age, 53.9 years) with biopsy-proven cervical cancer who underwent pelvic MR imaging including conventional DWI and reduced FOV DWI before therapy. Two observers independently rated image quality for reduced FOV DWI and conventional DWI regarding anatomic detail, lesion conspicuity, presence of artifacts, and overall image quality using the following 4-point scale. Quantitative analysis was performed by measuring the ADC value of the tumor. The Wilcoxon signed-rank test was used to compare qualitative scores and mean ADC value between two DWI sequences. RESULTS: Reduced FOV DWI achieved significantly better anatomic detail, lesion conspicuity, presence of artifacts, and overall image quality compared to conventional DWI (p < 0.05). There was no significant difference in mean tumor ADC value between the two DWI sequences (0.990 × 10(−3) mm(2) s(−1) ± 0.364 at reduced FOV DWI vs 1.253 × 10(−3) mm(2) s(−1) ± 0.387 at conventional DWI) (p = 0.067). CONCLUSION: Reduced FOV DWI shows better image quality in terms of anatomic detail and lesion conspicuity with fewer artifacts compared to conventional DWI. ADVANCE IN KNOWLEDGE: Reduced FOV DWI may enhance diagnostic performance for evaluation of cervical cancer.

Sclerosing stromal tumor (SST) is a rare benign ovarian neoplasm classified as a type of sex cord stromal tumor that occurs predominantly in young patients. Several reports have described the US, CT and MR features of SST, but there have been no reports of a bilateral calcified SST in a child. We present a case of a bilateral SST of the ovary with calcification in a 12-year-old premenarchal girl and describe the US, CT, MR and pathological findings.

Introduction: We sought to investigate the impact of fatty liver disease (FLD) on prostate cancer (PCa) screening by estimating the odds of having a prostate-specific antigen (PSA) value over the cutoff used to prompt for the recommendation of prostate biopsy.Methods: Between 2007 and 2013, 18 533 native Korean men eligible to receive a serum PSA test, liver profiles, and abdominal ultrasonography were recruited. Logistic regression was used to estimate the odds of an abnormal PSA (≥2.5 ng/mL) in these men (age 45-75 years, PSA≤10 ng/mL) in relation to FLD. The FLD status was categorized as normal, mild, moderate, and severe grade by abdominal sonography.Results: A total of 16 563 men (89.4%) were included in the study after applying the inclusion criteria. Liver profiles were negatively correlated with the serum PSA level. After controlling for age and obesity, there was a statistically significant trend towards a lower likelihood of having a serum PSA level of ≥2.5 ng/mL with severe FLD, having a 34.7% lower likelihood (odds ratio 0.653, 95% confidence interval 0.477–0.88; pConclusions: Severe FLD is an independent predictor of a lower likelihood of having abnormal PSA level. Further studies are needed to better define these results in clinical biopsy practice.

The purpose of this study is to assess the advantages of additional multiplanar sliding-slab averaging review of 2-mm-thick (thin) sections over stack review of 5-mm-thick (thick) sections in difficult cases of 2-mSv CT in adolescents and young adults with suspected appendicitis.We included 149 patients (mean age, 28.0 years; 61 male patients and 88 female patients) for whom the initial CT reports were inconclusive for the diagnosis of appendicitis. Five independent radiologists retrospectively reviewed the thick sections in the stack mode and then the thin sections using sliding-slab averaging. In each review, they rated the likelihood of appendicitis and the appendix visualization using 5- and 3-point Likert scales, respectively. Diagnostic performance and confidence were compared between the two reviews using ROC analysis, McNemar tests, and Wilcoxon signed-rank tests.The pooled AUCs were 0.90 and 0.93 for the stack and sliding-slab averaging reviews, respectively (90% CI for the difference, 0.002-0.06; p = 0.087). For the individual readers, the sliding-slab averaging review tended to increase the AUC (range, 0.86-0.93 for stack vs 0.87-0.97 for sliding-slab averaging review), improve the confidence in diagnosing (mean score, 3.6-4.7 vs 3.9-4.7) or ruling out (1.6-2.1 vs 1.5-1.9) appendicitis, reduce indeterminate interpretations (0-15% vs 0-11%), and enhance the normal appendix visualization (1.1-1.7 vs 1.1-1.9), although the differences were not always statistically significant.Sliding-slab averaging review of thin sections is helpful when the diagnosis of appendicitis is difficult at 2-mSv CT in adolescents and young adults.

Background Although there is growing evidence of relationship between obesity and some specific stone compositions, results were inconsistent. Due to a greater relationship between metabolic syndrome and some specific stone type, obesity measured by body mass index (BMI) has limitation in determining relationship between obesity and stone compositions. The aim of this study was to determine the relationship among BMI, visceral fat, and stone compositions. Methods We retrospectively reviewed data of patients with urinary stone removed over a 5 year period (2011–2014). Data on patient age, gender, BMI, urinary pH, stone composition, fat volumes (including visceral fat, subcutaneous fat, total fat, waist circumference), and ratio for visceral to total fat using computed tomography based delineation were collected. To figure out the predicting factor while adjusting other confounding factors, discriminant analysis was used. Results Among 262 cases, average age was 52.21 years. Average BMI and visceral fat were 25.03 cm2 and 124.75 cm2, respectively. By chi square test, there was significant (p

OBJECTIVE. Our objective is to show the various clinical applications of MDCT enterography for evaluating small-bowel disease, with a focus on the added value of 3D imaging.CONCLUSION. MDCT and refined 3D imaging processes can offer a full examination of the small bowel as well as powerful information about the bowel and its surrounding structures.

OBJECTIVE. The purpose of this study was to determine the incidence of inferior phrenic arterial bleeding after liver transplantation in adult patients and to describe its clinical manifestations and predictive CT features.CONCLUSION. Inferior phrenic arterial bleeding occurs frequently and is one of the major postoperative bleeding sites in patients undergoing liver transplantation. Awareness of its common clinical manifestations and predictive CT features is essential for prompt diagnosis and treatment of this early vascular complication, and this knowledge can help to avoid unnecessary reoperation and catastrophic hypotension.

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths worldwide. Early detection and accurate preoperative staging of early gastric cancer (ECG) offers the best prognosis and is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection. Recent advances in computed tomographic technology and three-dimensional imaging software have enabled more accurate gastric imaging. Virtual gastroscopy (VG) is helpful in the detection and evaluation of EGC in the same way as gastroscopy. VG has a wider field of view than conventional gastroscopy, the angle of the virtual cancer can be adjusted omnidirectionally, and it has no blind point because retrospective reconstruction is available. Thus, VG is a promising method for evaluating gastric lesions despite its limitations. This report describes the clinical usefulness of VG with multidetector row computed tomography for EGC and axial computed tomography.

The study was conducted, with institutional review board approval and informed patient consent, to assess the feasibility and diagnostic effectiveness of three-dimensional direct multi-detector row computed tomographic (CT) cholangiography for determining the extent of bile duct invasion by hilar cholangiocarcinoma. Eleven patients underwent contrast material-enhanced direct multi-detector row CT cholangiography of the primary and secondary biliary confluence levels and then surgical resection. In most patients, CT cholangiography was tolerable and yielded excellent or good opacification of the biliary tree. CT cholangiography enabled a correct diagnosis of the extent of ductal involvement at all 11 primary confluence levels and at 18 of the 19 secondary confluence levels. Three secondary confluences, which could not be analyzed owing to nonopacification or poor opacification, proved to be involved by hilar cholangiocarcinoma. The authors conclude that three-dimensional direct multi-detector row CT cholangiography is accurate and feasible for defining the extent of ductal invasion by hilar cholangiocarcinoma, especially in patients with preliminary biliary drainage.

Malignant mesothelioma of the tunica vaginalis testis is a rare, but often fatal, malignancy that usually appears during the fourth decade and has a strong relationship with occupational exposure to asbestos and long-lasting hydrocele. We present a case involving a 36-year-old man without a history of hydrocele, trauma, or exposure to asbestos who developed malignant mesothelioma.

Laparoscopic mini-gastric bypass surgery is a safe and simple surgical intervention for treating morbid obesity and diabetes mellitus and is now being performed more frequently. Radiologists must be critical in their postoperative evaluation of these patients. In this pictorial review, we explain and illustrate the surgical technique, normal postoperative anatomy, and associated complications as seen on imaging examinations, including fluoroscopy and computed tomography.

A 49-year-old man was referred with constipation that had lasted for a few months. On colonoscopy, a subepithelial tumour more than 4 cm in size was seen in the rectum. He underwent endoscopic ultrasound and pelvic magnetic resonance imaging. He was preoperatively diagnosed with a rectal duplication cyst based on imaging studies. However, the final histopathologic diagnosis after transanal excision of the rectal mass was rectal carcinoid tumour with tailgut cyst. Tailgut cysts are very rare congenital lesions in the presacral area and are most often discovered incidentally in middle-aged women. It is difficult to distinguish the imaging appearance of tailgut cysts from that of many other retrorectal cysts. Malignant transformation of tailgut cysts has been estimated to occur in 2 to 13% of cases. We report the diagnostic difficulties encountered in a case of carcinoid tumour arising from a tailgut cyst in a male patient.

Objective To determine the relationship between body mass index (BMI), visceral adipose tissue (VAT), and stone components. Methods A cross-sectional study has been done for urinary stone cohort between 2010 and 2012. Data on patient's age, gender, BMI, urinary pH, stone components, and VAT using computed tomography–based delineation were collected. Obesity was defined as BMI ≥ 25 kg/m 2 or as VAT ≥ 100 cm 2 . To compare the differences between the types of stones, multinomial logistic regression analyses were conducted. Results Of 203 cases, 49.3% patients were obese based on BMI, and 65.5% were obese using VAT criteria. Multinomial logistic regression analysis revealed that obesity defined by VAT was found to be associated with uric acid stones compared with calcium phosphate stones (odds ratio [OR] 6.544, 95% confidence interval [CI], P = .030) and mixed calcium oxalate phosphate stones (OR 5.582, 95% CI, P = .038). Similar results were observed in calcium oxalate stones over calcium phosphate stones (OR 2.984, 95% CI, P = .032) and calcium oxalate phosphate stones (OR 2.542, 95% CI, P = .041). On the contrary, obesity defined based on BMI has no correlation over all types of urinary stone components. Conclusion This result implies that VAT has a more important role in uric acid and calcium oxalate stone formation than total body fat, represented by BMI.

Various diseases of the urinary bladder can be demonstrated as being polypoid, a nodular bladder mass or as focal bladder wall thickening. This includes malignant or benign neoplasms, urinary stones, or other inflammatory bladder conditions. In daily practice many of these bladder diseases are easily confused with bladder cancer. On the other hand, ultrasonography (US) is safe and can be easily applied as a screening modality or an initial evaluating tool for urinary bladder disease. Furthermore, additional three-dimensional (3D) volumetric techniques can support more delicate delineation of these lesions. This study presents a 3D volumetric US for bladder lesions, and demonstrates various pathological conditions of the urinary bladder ranging from bladder cancer to other benign lesions.

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of breast cancer with prognostic factors.335 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) and ductal carcinoma in situ (DCIS) who underwent breast MRI with diffusion-weighted imaging were included in this study. ADC of breast cancer was calculated using two b factors (0 and 1000 s mm(-2)). Mean ADCs of IDC NOS and DCIS were compared and evaluated. Among cases of IDC NOS, mean ADCs were compared with lymph node status, size and immunochemical prognostic factors using Student's t-test. ADC was also correlated with histological grade using the Kruskal-Wallis test.Mean ADC of IDC NOS was significantly lower than that of DCIS (p0.001). However, the mean ADC of histological grade of IDC NOS was not significantly different (p=0.564). Mean ADC of oestrogen receptor (ER)-positive or progesterone receptor (PR)-positive cancer was significantly lower than that of ER-negative or PR-negative cancer (p=0.003 vs p=0.032). Mean ADC of Ki-67 index-positive cancer was significantly lower than that of Ki-67 index-negative cancer (p=0.028). Mean ADC values of cancers with increased microvascular density (MVD) were significantly lower than those of cancer with no MVD increase (p=0.009). No correlations were observed between mean ADC value and human growth factor receptor 2 expression, tumour size and lymph node metastasis.Low ADC value was correlated with positive expression of ER, PR, increased Ki-67 index, and increased MVD of breast cancer.

To assess MR findings and diagnostic performance for differentiating malignant from benign hepatic masses in recurrent pyogenic cholangitis (RPC).During a recent 6-year period, we performed MRI in 352 patients with RPC. Among them, 58 had confirmed hepatic masses; cholangiocarcinoma (n = 15), abscess (n = 37), inflammatory pseudotumor (n = 3), biloma (n = 3). Two radiologists assessed MR findings including enhancement patterns, intratumoral appearance, peritumoral changes, mass location, and multiplicity. They also graded the malignancy using common MR findings. The receiver operating characteristic analysis and Chi-square test were used. The κ statistics was used to determine interobserver agreement.The common findings for cholangiocarcinoma were thin and lobulated enhancement at the periphery (n = 8, 53%, P0.05); ill-defined enhancement (n = 7, 47%, P0.05); slightly high signal on T2 (n = 13, 87%, P0.05); mass located in the same lobe of atrophy (n = 11, 73%, P0.05) and portal vein thrombosis (n = 15, 100%, P0.05). The common findings for benign mass were target-like enhancement (n = 36, 84%, P0.05); cluster appearance (n = 15, 35%, P0.05); central, fluid-like space (n = 29, 67%, P0.05); peritumoral regional high signal on T2 (n = 32, 74%, P0.05); multiplicity(n = 21, 49%, P0.05). Interobserver agreement was excellent (κ = 0.81-1.000). Area under the curve (Az) for differentiating malignant masses was 0.989, sensitivity was 95.3%, and specificity was 95.3%. There was good interobserver agreement (κ = 0.74).MR imaging is very useful for differential diagnosis of malignant vs. benign hepatic masses in patients with RPC.

To assess the diagnostic accuracy of different reconstruction techniques using MDCT for gastric cancer detection compared with 2D axial CT.During 7 months, we performed CT examinations of 104 consecutive patients with gastric cancer and of a control group composed of 35 patients without gastric disease. All gastric cancer was pathologically proven by endoscopy and surgery. Among 104 patients with gastric cancer, 63 patients had early gastric cancer (EGC). Two radiologists retrospectively and independently interpreted the axial CT and three different reconstruction techniques including multiplanar reformation (MPR), transparent imaging (TI), and virtual gastroscopy (VG), using a commercially available, 3D workstation. They graded the presence or absence of gastric cancer in each image sets using a five-point scale and, if present, they assessed its location. Diagnostic accuracy was compared using the area under the receiver operating characteristic curve (Az) for both gastric cancer and only EGC. Sensitivity and specificity were also calculated for each image technique. The k statistics were used to determine inter-observer agreement.The diagnostic accuracy for overall gastric cancer detection for each of the image sets was as follows: 2D axial CT (Az = 0.858); MPR (Az = 0.879); TI (Az = 0.873); and VG (Az = 0.928). VG had significantly better performance than 2D axial CT (p = 0.016). The sensitivity and specificity were as follows: 76.7% and 82.9% in axial CT; 79.6% and 85.7% in MPR; 91.3% and 80% in TI; and 95.1% and 74.3% in VG. In EGC, the diagnostic performance for its detection was as follows: axial CT (Az = 0.777); MPR (Az = 0.811); TI (Az = 0.825); and VG (Az = 0.896). VG had significantly better performance than both 2D axial CT (P = 0.006) and MRP (P = 0.038). The sensitivity and specificity were as follows: 62.9% and 82.9% in axial CT; 67.7% and 85.7% in MPR; 85.5% and 80% in TI; and 91.9% and 74.3% in VG. The inter-observer agreement showed substantial agreement (κ = 0.67-0.75).Among the different reconstruction techniques, VG accurately detects gastric cancer and is especially useful for EGC compared with 2D axial CT.

Purpose To assess the diagnostic ability of MRI and EUS for differentiating benign from malignant pancreatic cyst focusing on cyst communication with pancreatic duct. Materials and methods During 44 months, we performed MRI on 65 pancreatic cysts. Among them, 36 patients had confirmed cyst communication with duct by ERCP or surgery and 39 patients underwent EUS. Fifty-one had proven by surgery or aspiration. Among them, 36 had confirmed malignant cysts. Two radiologists independently graded cyst communication with duct and the likelihood of malignancy. When the readers’ interpretations differed, third opinion was obtained. They also measured the size of cyst and main duct. The diagnostic performance was analyzed using the ROC curve. The Mann–Whitney U test and κ statistics were used to determine interobserver agreement. Results The Az of MRI and EUS for determining diagnostic performance regarding the cyst communication with duct, were 0.931 and 0.930, without statistically difference ( p = 0.6). Interobserver agreement was excellent ( κ = 0.81) on MRI and substantial ( κ = 0.69) on EUS. The Az of MRI and EUS for assessing diagnostic performance to differentiate malignant from benign cyst, was 0.902 and 0.923, without statistically difference ( p = 0.587). Interobserver agreement was excellent ( κ = 0.81) on MRI and moderate ( κ = 0.47) on EUS. The mean cyst size (3.98 cm + 2.74: 3.17 cm + 1.26, p = 0.327) and the duct size (5.20 mm + 3.22: 4.39 mm + 4.12, p = 0.227) showed no statistically difference between malignant and benign cysts. Conclusion MRI and EUS can accurately assess pancreatic cyst communication with duct and are very useful for obtaining a differential diagnosis of malignant cyst versus benign pancreatic cyst.

Objective To evaluate the safety and technical success rate of an ultrasound-guided fiducial marker implantation in preparation for CyberKnife radiation therapy. Materials and methods We retrospectively reviewed 270 percutaneous ultrasound-guided fiducial marker implantations in 77 patients, which were performed from June 2008 through March 2011. Of 270 implantations, 104 were implanted in metastatic lymph nodes, 96 were in the liver, 39 were in the pancreas, and 31 were in the prostate. During and after the implantation, major and minor procedure-related complications were documented. We defined technical success as the implantation enabling adequate treatment planning and CT simulation. Results The major and minor complication rates were 1% and 21%, respectively. One patient who had an implantation in the liver suffered severe abdominal pain, biloma, and pleural effusion, which were considered as major complication. Abdominal pain was the most common complication in 11 patients (14%). Among nine patients who had markers inserted in the prostate, one had transient hematuria for less than 24 hours, and the other experienced transient voiding difficulty. Of the 270 implantations, 261 were successful (97%). The reasons for unsuccessful implantations included migration of fiducial markers (five implantations, 2%) and failure to discriminate the fiducial markers (three implantations, 1%). Among the unsuccessful implantation cases, six patients required additional procedures (8%). Conclusion The symptomatic complications following ultrasound-guided percutaneous implantation of fiducial markers are relatively low. However, careful consideration of the relatively higher rate of migration and discrimination failure is needed when performing ultrasound-guided percutaneous implantations of fiducial markers.

To assess the clinical usefulness of free-breathing 3D MRCP in non-cooperative patients compared conventional breath-hold 2D MRCP.We performed FB navigator-triggered 3D MRCP using prospective acquisition correction and BH 2D MRCP in 48 consecutive, non-cooperative patients among 772 patients. Thirteen patients had malignant obstruction. Two radiologists independently graded the likelihood of a malignant obstruction, the overall image quality, and the visibility of ten, individual anatomic segments of both the biliary and pancreatic duct in each sequence. The area under the ROC curve and the repeated measures analyses of variance with multiple comparisons were used for the comparison. The κ statistics were used for interobserver agreement.The diagnostic performance for detecting malignancy was significantly higher on FB MRCP (A(z)=0.962) than on either BH SS-RARE (A(z)=0.820, P0.0185) or MS-HASTE MRCP (A(z)=0.816, P0.0067). Interobserver agreement was excellent for FB MRCP (κ=0.889) and fair for both BH SS-RARE (κ=0.578) and MS-HASTE MRCP (κ=0.49). FB MRCP had a significantly higher technical quality than BH MRCP (P0.001). FB MRCP was seen to have statistically better visibility of peripheral IHD, right main IHD, CHD, cystic duct, and CBD than BH MRCP (P0.001). FB MRCP and BH SS-RARE MRCP had statistically better visibility of both the left main IHD and pancreatic duct than did BH MS-HASTE MRCP (P0.001).FB 3D MRCP is useful for non-cooperative patients in whom conventional BH 2D methods cannot be used successfully.

Acute phlegmonous infection of the gastrointestinal tract is characterized by purulent inflammation of the submucosa and muscular layer with sparing of the mucosa. The authors report a rare case of acute diffuse phlegmonous esophagogastritis, which was well diagnosed based on the typical chest computed tomographic (CT) findings and was successfully treated. A 48-yr-old man presented with left chest pain and dyspnea for three days. Chest radiograph on admission showed mediastinal widening and bilateral pleural effusion. The patient became febrile and the amount of left pleural effusion is increased on follow-up chest radiograph. Left closed thoracostomy was performed with pus drainage. A CT diagnosis of acute phlegmonous esophagogastritis was suggested and a surgery was decided due to worsening of clinical condition of the patient and radiologic findings. Esophageal myotomies were performed and the submucosal layer was filled with thick, cheesy materials. The patient was successfully discharged with no postoperative complication.

We report colonoscopic features of an intussuscepted Meckel’s diverticulum, presenting with hematochezia. A 35-year-old woman presented to the emergency room with acute onset, transient, sharp, severe epigastric pain that began 6 h earlier. Colonoscopy revealed a reddish, soft, fist-sized polypoid lesion in the terminal ileum. The lesion was misinterpreted as a hematoma by an inexperienced endoscopist. The patient began to complain of intermittent, severe periumbilical pain following the colonoscopic examination. Subsequent computed tomography showed an enteric intussusception. An exploratory laparotomy revealed an intussuscepted Meckel’s diverticulum, with transmural infarction. Colonoscopy was of little use in assessing the intussusception. However, colonoscopic examination may be performed initially, especially in an intussuscepted Meckel’s diverticulum presenting with hematochezia. Endoscopists should note the endoscopic features of an intussuscepted Meckel’s diverticulum.

To evaluate the feasibility of 3D CT enterography using oral gastrografin in patients with small bowel obstruction (SBO), focusing on improving diagnostic performance as compared with the use of axial CT imagings and fluoroscopic findings. For a 10-month period, 18 patients with known SBO detected clinically and radiologically were enrolled. In all patients, gastrografin was ingested prior to CT enterography. Twelve patients underwent a fluoroscopic examination. Images were randomly assessed for confidence for the level, for the cause of SBO, and for the assessment of the interpretability of each image by two gastrointestinal radiologists. The results were considered statistically significant using the Wilcoxon rank sum test. All patients (100%) well tolerated the administration of oral gastrografin. The use of 3D CT enterography significantly improved diagnostic confidence for the interpretation of the level, cause of SBO, and the assessment of the interpretability of each image as compared with the use of axial CT images (P

Accurate evaluation of local extent in bladder cancer is important to determine the optimal therapeutic strategy and to predict the outcome of treatment. The purpose of this study is to evaluate the accuracy of 3D volumetric reconstructed US in the assessment of tumor detection and serosal invasion in patients with bladder cancer. A total of 14 patients with findings of bladder cancer determined with the use of cystoscopy was examined with the use of bladder two-dimensional (2D) US and subsequent 3D US. US findings were compared with cystoscopy findings and the pathological stage after a TURB or a radical cystectomy in a double-blinded manner. The sensitivity of preoperative tumor staging was 67.9% for 2D US and sensitivity was 78.6% for 3D US. 3D US was superior sensitivity than 2D US (P

We discuss the clinical impacts of early postoperative bleedings after LDLT and CT findings or CT angiographic findings compared with angiography according to the various bleeding causes. Sudden development of hematoma as well as extravasation of contrast material on CT scan are thought to be predictive CT findings of early postoperative bleeding in post-hepatic transplant patients. Careful consideration for these findings can prevent the progression into a catastrophic status that requires surgical management.