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Background Guidelines recommending additional imaging for adrenal nodules lack relevant epidemiologic evidence. Purpose To measure the prevalence of adrenal nodules detected at staging CT in patients with potentially resectable gastric cancer and the proportion of patients with malignant nodules among them. Materials and Methods This retrospective study included 10 250 consecutive patients (median age, 63 years; interquartile range, 53-71 years; 6884 men) who underwent staging CT and had potentially resectable gastric cancer in a tertiary center (May 2003 to December 2018). All 10 250 CT studies were retrospectively reviewed, and patients with adrenal nodules (or thickening ≥10 mm) were identified to measure the prevalence of adrenal nodules. Among patients with adrenal nodules, the per-patient proportions of malignant nodules, adrenal metastasis from gastric cancer, and additional adrenal examinations were measured. A secondary analysis was performed by using data from the original CT reports. The same metrics that were used in the retrospective review were assessed. Results The prevalence of adrenal nodules was 4.5% (95% CI: 4.1, 4.9; 462 of 10 250). The proportions of malignant nodules and adrenal metastasis from gastric cancer were 0.4% ( 95% CI: 0.1, 1.6; two of 462) and 0% (95% CI: 0.0, 0.8; 0 of 462), respectively. A total of 27% of the patients (95% CI: 23, 31; 123 of 462) underwent additional adrenal examination. According to original CT reports, the prevalence of adrenal nodules and the proportions of malignant nodules, adrenal metastases from gastric cancer, and additional adrenal examination were 2.7% (95% CI: 2.4, 3.0; 272 of 10 250), 0.7% (95% CI: 0.1, 2.6; two of 272), 0% (95% CI: 0.0, 1.4; 0 of 272), and 42.6% (95% CI: 36.7, 48.8; 116 of 272), respectively. Conclusion Although adrenal nodules were detected frequently on staging CT images of patients with otherwise resectable gastric cancer, these nodules were rarely malignant. ©RSNA, 2021

Please see the Editorial Comment by Douglas S. Katz discussing this article. BACKGROUND. Adoption of low-dose CT for the diagnosis of appendicitis has been slow in children and in adults, partly be...

Background There are ongoing efforts to reduce CT radiation exposure for the diagnosis of appendicitis. Recent guidelines recommend using clinical scoring systems to triage patients who need imaging examinations. Purpose To determine whether patient triaging with scoring systems can reduce CT use without a loss of diagnostic accuracy in adolescents and young adults suspected of having appendicitis. Materials and Methods This retrospective study used data from a previous multicenter randomized controlled trial conducted between December 2013 and August 2016. Five scoring systems (adult appendicitis, appendicitis inflammatory response, modified Alvarado, Broek, and Christian scores) were used to categorize patients into low-, intermediate-, or high-probability groups. CT use was simulated for only the intermediate-probability group. The primary outcomes were CT reduction rate, sensitivity, and specificity. The CT reduction rate was defined as the proportion of patients in low- and high-probability groups who would not have to undergo CT among all patients. Sensitivity and specificity were calculated in the overall diagnostic pathway using each scoring system and subsequent CT. As a secondary analysis, to maintain the diagnostic accuracy to a level of when CT was used for all patients with suspected appendicitis, new cutoff values for probability group stratification targeting 97.6% sensitivity and 94.9% specificity were applied for each of the scoring systems. Results A total of 2888 patients (mean age ± standard deviation, 28 years ± 9; 1580 women and 1308 men) with suspected appendicitis were evaluated, of whom 1088 had and 1800 did not have appendicitis. The CT reduction rates of the five scoring systems ranged from 55.6% (1606 of 2888 patients) to 71.1% (2053 of 2888), but at the cost of sensitivity (range, 48.7% [530 of 1088] to 81.2% [883 of 1088]) and specificity (range, 79.0% [1422 of 1800] to 97.8% [1761 of 1800]). Targeting 97.6% sensitivity and 94.9% specificity, the CT reduction rates of all five scoring systems were 0% (0 of 2888). Conclusion Using clinical scoring systems in triaging patients for selective CT use led to a considerable loss of diagnostic accuracy. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mellnick in this issue.

To compare 2-mSv CT and conventional-dose CT (CDCT, typically 7–8 mSv) regarding final diagnosis and patient disposition following equivocal CT results in adolescents and young adults with suspected appendicitis. In total, 3074 patients of 15–44 years (28 ± 9 years, 1672 women) from 20 hospitals were randomized to undergo contrast-enhanced 2-mSv CT (n = 1535) or CDCT (n = 1539) from December 2013 through August 2016. One hundred sixty-one radiologists prospectively rated the likelihood of appendicitis in a Likert scale (i.e., grades 1–5). The final diagnosis was based on CT image, surgical, pathologic, and clinical findings. Post hoc analysis was performed for final diagnosis, surgical procedure, and delay in patient management following equivocal results (i.e., grade 3). The 2-mSv CT and CDCT groups were comparable for final diagnosis following equivocal results, including confirmed appendicitis (1.2% [18 patients] vs. 1.2% [19], p > 0.99), negative appendectomy (0.1% [2] vs. 0.3% [4], p = 0.53), and perforated appendicitis (0.1% [1] vs. 0.2% [3], p = 0.53). More patients were confirmed as not having appendicitis following equivocal results in the CDCT group than in the 2-mSv CT group (2.2% [34] vs. 1.0% [16], p = 0.016). The two groups were comparable for the need of appendectomy (1.4% [22] vs. 1.5% [23], p > 0.99), need of additional imaging tests (0.7% [11] vs. 1.1% [17], p = 0.35), and delay in patient management following equivocal results. 2-mSv CT is comparable to CDCT regarding final diagnosis and patient disposition following equivocal CT results. • Our results strengthen evidence justifying the use of low-dose CT instead of conventional-dose CT (CDCT) in adolescents and young adults with suspected appendicitis. • The 2-mSv CT and CDCT groups were comparable for final diagnosis following equivocal CT results, including confirmed appendicitis (1.2% vs. 1.2%, p > 0.99), negative appendectomy (0.1% vs. 0.3%, p = 0.53), and perforated appendicitis (0.1% vs. 0.2%, p = 0.53). • The two groups were comparable for the need for appendectomy (1.4% vs. 1.5%, p > 0.99), need for additional imaging tests (0.7% vs. 1.1%, p = 0.35), and delay in patient management, following equivocal CT results.

Inactivation of TP53, a tumor suppressor gene, is associated with the development of several malignancies, including gastric cancer (GC). The present study aimed to evaluate the correlation between the overexpression of p53 and survival in different Lauren-type GCs. From May 2003 to December 2019, 3608 GC patients treated endoscopically or surgically at the Seoul National University Bundang Hospital were enrolled for the study. Immunohistochemical staining for p53 was performed on all endoscopic and surgical gastric specimens. Clinicopathologic characteristics with Lauren classification, survival rate, and cancer recurrence were analyzed according to p53 overexpression. Among 3608 GC patients, p53 overexpression was seen in 1334 patients (37%). p53 overexpression was associated with lower depth of invasion (P = 0.026) and Early gastric cancer (P = 0.044) in intestinal-type GC, and with advanced TNM stage (P

Differentiating complicated appendicitis has become important, as multiple trials showed that non-operative management of uncomplicated appendicitis is feasible. We developed and validated a diagnostic model to differentiate complicated from uncomplicated appendicitis. This retrospective study included 1153 patients (mean age ± standard deviation, 30 ± 8 years) with appendicitis on CT (804 patients for development, and 349 for validation). Complicated appendicitis was confirmed in 300 and 121 patients in the development and validation datasets, respectively. The reference standard was surgical or pathological report except in 7 patients who underwent percutaneous abscess drainage. We developed a model using multivariable logistic regression and Bayesian information criterion. We assessed calibration and discriminatory performance of the model in the validation dataset via calibration plot and the area under the curve (AUC), respectively. We measured sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and proportion of false- and true-negatives of the model in the validation dataset, targeting 95% sensitivity. Five CT features (contrast-enhancement defect of the appendiceal wall, abscess, moderate or severe periappendiceal fat stranding, appendiceal diameter, and extraluminal air) and percentage of segmented neutrophil were included in our model. The calibration slope was 1.03, and AUC was 0.81 (95% CI 0.77–0.85) in the validation dataset. The sensitivity, specificity, PPV, NPV, and proportion of false- and true-negatives were 93.4% (91.8–99.1), 28.1% (13.6–24.1), 40.8% (35.0–46.8), 88.9% (79.3–95.1), 2.3%, and 18.3%, respectively. Our model may identify patients with unequivocally uncomplicated appendicitis, who may benefit from non-operative management with low risk of failure.

To test whether the difference in sensitivity or specificity between 2-mSv CT and conventional-dose CT (CDCT) for the diagnosis of appendicitis differs across subgroups of adolescents and young adults with suspected appendicitis. We used the per-protocol analysis data of a trial conducted between Dec 2013 and Aug 2016, including 2773 patients (median age [interquartile range], 28 [21–35] years) and 160 radiologists from 20 hospitals. We defined subgroups by sex, body size, clinical risk scores for appendicitis, time of CT examination (i.e., working vs. after hours), CT machines, radiologists’ experience, previous site experience in 2-mSv CT, and site practice volume. We drew forest plots and tested for additive or multiplicative interaction between radiation dose and subgroup attributes. If any subgroup had fewer than 200 patients, we considered the results from that subgroup not meaningful. For most subgroups, the 95% CIs for the differences in sensitivity and specificity were 4.0 percentage points or narrower and contained the minute overall between-group differences. There was no significant interaction on sensitivity or specificity. A few subgroups, including those of extreme body sizes, high appendicitis inflammatory response scores, and hospitals with small appendectomy volume, were regarded to have insufficient numbers of patients. There was no notable subgroup heterogeneity, which implies that 2-mSv CT can replace CDCT in diverse populations. Further studies are needed for the subgroups for which we had only small data. • The minute difference in sensitivity or specificity between the 2-mSv CT and conventional-dose CT (typically 7 mSv) groups were consistent across various patient or hospital characteristics. • These results indicate that 2-mSv CT can replace conventional-dose CT in diverse populations. • Further studies are needed to confirm whether 2-mSv CT can replace conventional-dose CT in patients of extreme body sizes, high appendicitis inflammatory response scores, or hospitals with small appendectomy volume, as those subgroups in our data included limited numbers of patients.

OBJECTIVE. The purpose of this study is to propose a sensitive CT criterion (the presence of any of 10 CT features) for complicated appendicitis that could be used in the nonoperative management of appendicitis and to compare the diagnostic performance of this sensitive CT criterion with that of gestalt assessment. MATERIALS AND METHODS. This retrospective study, which was conducted in a tertiary teaching hospital, included 100 patients with suspected appendicitis on CT. Complicated appendicitis, defined as gangrenous or perforated appendicitis, was pathologically or surgically confirmed in 32 patients. Six radiologists independently determined the presence of 10 previously reported CT features of complicated appendicitis (contrast enhancement defect of the appendiceal wall, abscess, extraluminal air, intraluminal air, extraluminal appendicolith, intraluminal appendicolith, moderate-to-severe periappendiceal fat stranding, periappendiceal fluid, ileus, and ascites) and rated the likelihood score for complicated appendicitis using gestalt assessment. The sensitivity and specificity of CT for complicated appendicitis were measured by the presence of any of 10 CT features (the any-of-10-features criterion) and by the radiologists' gestalt assessment. Pooled sensitivity and specificity were compared using a generalized linear mixed model. RESULTS. The pooled sensitivity of the presence of any of 10 CT features was higher than that of gestalt assessment (92% vs 64%; difference, 28% [95% CI, 10-46%]; p < 0.001), although the pooled specificity was lower (43% vs 76%; difference, -33% [95% CI, -48% to -17%]; p < 0.001). CONCLUSION. The pooled sensitivity of the presence of any of 10 CT features was higher than that of gestalt assessment, at the cost of lower specificity. For prudent selection of patients who should receive nonoperative treatment of appendicitis, the any-of-10-features criterion may be used to decrease treatment failure associated with a false-negative diagnosis of complication.

Background US has served as a standard surveillance tool for hepatocellular carcinoma (HCC); however, the detection rate and false referral rate with this modality are suboptimal. Purpose To evaluate the added value of perfluorobutane-enhanced US when combined with conventional B-mode US as an HCC surveillance tool in participants with liver cirrhosis. Materials and Methods This prospective multi-institution diagnostic trial (https://ClinicalTrials.gov, NCT02188901) used an intraindividual comparison design in a single arm of study participants and was conducted at five referral hospitals. Eligible participants who had liver cirrhosis related to viral hepatitis and were undergoing US for HCC surveillance were enrolled from October 2014 to August 2016. Immediately after completion of B-mode US but before performance of perfluorobutane-enhanced US, operating radiologists entered the results of B-mode US. After completion of subsequent perfluorobutane-enhanced US (Kupffer phase with or without vascular-phase US), the radiologists recorded the results. The presence of HCC was confirmed either with pathologic analysis or radiologically by using dynamic contrast material-enhanced CT or gadoxetic acid-enhanced MRI. The primary end points were the detection rate of early-stage HCC (Barcelona Clinic Liver Cancer staging system stage 0 or A) and false referral rate. The primary end points were compared in a per-participant manner by using the McNemar test. Results A total of 524 participants (mean age, 54 years ± 9 [standard deviation]) were included. Of these, 493 (94.1%) had liver cirrhosis related to the hepatitis B virus. Ten HCCs were confirmed in eight participants. The detection rate of early-stage HCC was not significantly improved by adding perfluorobutane-enhanced US to conventional B-mode US (difference, 0.4% [95% confidence interval: -0.3%, 1.1%]; P = .16). The false referral rate was significantly reduced (difference, -3.2% [95% confidence interval: -5.0%, -1.4%]; P < .001). Conclusion The addition of perfluorobutane-enhanced US to conventional B-mode US reduced the false referral rate without a significant improvement in the detection rate of early-stage hepatocellular carcinoma for surveillance in a population in which the hepatitis B virus predominated. © RSNA, 2019 Online supplemental material is available for this article.

Type 2 autoimmune pancreatitis (AIP) typically presents with diffuse or focal enlargement of the pancreas; however, its diverse clinical presentation has not yet been clarified. We herein described a 46-year-old man with a 1-month history of ulcerative colitis who presented with imaging features of a mass-like lesion in the pancreatic body with upstream duct dilatation and serum CA19-9 elevation. He underwent laparoscopic distal pancreatectomy with splenectomy for suspected malignancy. Histologically, the area radiologically suspected to be duct dilatation consisted of necrotic tissue, in which the disrupted main pancreatic duct was involved. The area radiologically suspected to be the mass lesion showed features of pancreatitis without discrete mass. In addition, several ducts showed neutrophilic duct injury similar to granulocytic epithelial lesions observed in type 2 AIP. Immunohistochemistry revealed the aberrant expression of IL-8 in the pancreatic ductules and infiltrating CD3-positive T-lymphocytes, findings recently identified in type 2 AIP. The present case is not typical for either type 2 AIP or other known conditions, but extreme examples of type 2 AIP may present with ductal obstruction because of severe neutrophilic duct injury. IL-8 immunostaining may also assist in establishing a diagnosis of type 2 AIP with an atypical presentation.

Summary: Background: The long-term effects of radical resection on quality of life may influence the treatment selection. The objective of this study was to determine whether abdominoperineal resection has a better effect on the quality of life than sphincter preservation surgery at 3 years after surgery Methods: This prospective, cohort study included patients who underwent radical resection for low rectal cancer. The primary outcomes were European Organisation for Research and Treatment of Cancer QLQ-C30 and CR38 quality of life scores 3 years after surgery, which were compared with linear generalised estimating equations, after adjustment for baseline values, a time effect, and an interaction effect between time and treatment. The secondary outcomes included sexual-urinary functions and oncological outcomes. The study was registered with ClinicalTrials.gov (NCT01461525). Findings: Between December 2011 and August 2016, 342 patients were enrolled: 268 (78•4%) underwent sphincter preservation surgery and 74 (21•6%) underwent abdominoperineal resection. The global quality of life scores did not differ between sphincter preservation surgery and abdominoperineal resection groups (adjusted mean difference, 4•2 points on a 100-point scale; 95% confidence interval [CI], −1•3 to 9•7, p = 0•1316). Abdominoperineal resection was associated with a worse body image (9•8 points; 95% CI, 2•9 to 16•6, p = 0•0052), micturition symptoms (−8•0 points; 95% CI, -14•1 to −1•8, p = 0•0108), male sexual problems (−19•9 points; 95% CI, -33•1 to -6•7, p = 0•0032), less confidence in getting and maintaining an erection in males (0•5 points on a 5-point scale; 95% CI, 0•1 to 0•8, p = 0•0155), and worse urinary symptoms (−5•4 points on a 35-point scale; 95% CI, −8•0 to −2•7, p

OBJECTIVE. The objective of our study was to compare diagnostic performance of 2-mSv CT and standard-dose CT (SDCT) for the diagnosis of perforated appendicitis in adolescents and young adults. MATERIALS AND METHODS. We used the intention-to-treat analysis set of a pragmatic randomized controlled trial involving 3074 patients (age range, 15-44 years) with suspected appendicitis and 161 radiologists from 20 hospitals. The patients were randomized to undergo either 2-mSv CT or SDCT. Predefined endpoints were sensitivity and specificity. Considering potential verification bias caused by the difference in diagnostic interventions (2-mSv CT vs SDCT), we added endpoints of detection rate (DR) and false-referral rate. The reference standards were surgical or pathologic findings. We used Fisher exact tests. Sensitivity analyses included the following: first, a per-protocol analysis; second, an analysis of a surgical reference standard but not a pathologic reference standard; and, third, an analysis to adjust for site clustering. We tested for heterogeneity in DR and false-referral rate across various patient and hospital characteristics. RESULTS. The 2-mSv CT and SDCT groups were comparable regarding DR (5.1% [78/1535] vs 4.9% [76/1539]; 95% CI for the difference, -1.4 to 1.7 percentage points; p = 0.87), false-referral rate (3.1% [48/1535] vs 3.1% [47/1539]; 95% CI for the difference, -1.2 to 1.3 percentage points; p = 0.92), sensitivity (42.9% [78/182] vs 43.2% [76/176]; 95% CI for the difference, -10.6 to 9.9 percentage points; p > 0.99), and specificity (89.2% [305/342] vs 91.2% [354/388]; 95% CI for the difference, -6.4 to 2.3 percentage points; p = 0.38). Sensitivity analyses showed similar results. We found no significant subgroup heterogeneity. CONCLUSION. The performance of 2-mSv CT, with limited sensitivity but high specificity, is comparable to that of SDCT for the diagnosis of appendiceal perforation.

Helicobacter pylori (HP) is known to play an important role in the development of gastric cancer (GC). The aim of this study was to analyze the effect of HP eradication on the survival rate and cancer recurrence in patients who underwent subtotal gastrectomy for GC. Totally 1,031 patients diagnosed with gastric adenocarcinoma who received surgical treatment at the Seoul National University Bundang Hospital from 2003 to 2017 and positive for HP infection were analyzed. The overall and GC-related survival according to HP eradication were compared; risk factors for GC-specific death and cancer recurrence were analyzed, and propensity score matching (PSM) was performed. Statistically significant benefits of overall and GC-specific survival were observed in the eradicated group compared to the non-eradicated group (P

Conventionally, lymphatic spread is regarded as the principal mechanism by which haematogenous metastasis occurs in colorectal cancer. The aim of this cross sectional study was to determine the relative strengths of direct tumour spread, the presence of lymph node metastasis and histologically demonstrated venous invasion as drivers of haematogenous metastasis diagnosed at the time of resection of colorectal cancer. The data were drawn from a hospital database of consecutive bowel cancer resections between 1995 and 2017 inclusive. The presence of haematogenous metastasis was determined at the time of surgery by imaging or other investigations or operative findings. Where possible, histological confirmation was obtained. Specimen dissection and reporting followed a standardised procedure. Tumour staging was according to the 7th edition of the UICC/AJCC pTNM system. Analysis was by multivariable logistic regression. After exclusions 3133 patients remained, among whom 380 (12.1%) had one or more haematogenous metastases. In bivariate analyses, the frequency of haematogenous metastasis was directly associated with increasing T status (p

Background: The long-term effects of radical resection on quality of life may influence the treatment selection. The objective of this study was to compare the quality of life after sphincter preservation surgery or abdominoperineal resection for low rectal cancer. Methods: This prospective, cohort study included patients who underwent radical resection for low rectal cancer. The primary outcomes were EORTC QLQ-C30 and CR38 quality-of-life scores 3 years after surgery, which were compared with linear generalised estimating equations, after adjustment for baseline values, a time effect, and an interaction effect between time and treatment. The secondary outcomes included sexual-urinary functions and oncological outcomes. Findings: Between December 2011 and August 2016, 342 patients were enrolled: 268 (78·4%) underwent sphincter preservation surgery and 74 (21·6%) underwent abdominoperineal resection. After 3 years, abdominoperineal resection was associated with a worse body image (adjusted mean difference, 9·8 points on a 100-point scale; 95% CI, 2·9 to 16·6, p=0·0052), micturition symptoms (-8·0 points; 95% CI, -14·1 to -1·8, p=0·0108), male sexual problems (-19·9 points; 95% CI, -33·1 to -6·7, p=0·0032), less confidence in getting and maintaining an erection in males (0·5 points on a 5-point scale; 95% CI, 0·1 to 0·8, p=0·0155), and worse urinary symptoms (-5·4 points on a 35-point scale; 95% CI, -8·0 to -2·7, p

Purpose To measure the diagnostic yield and false-referral rate (FRR) of staging contrast material-enhanced chest CT based on the clinical stage from contrast-enhanced abdominal CT in patients with colon cancer. Materials and Methods This retrospective study included 1743 patients (mean age, 63.4 years; range, 18-96 years) with a diagnosis of colon cancer. The primary outcomes were diagnostic yield and FRR of contrast-enhanced chest CT in the detection of thoracic metastasis. The proportions of patients with occult thoracic metastasis and those undergoing pulmonary metastasectomy for true-positive metastases were key secondary outcomes. The outcomes were stratified according to clinical stage at contrast-enhanced abdominal CT. Results The diagnostic yields in clinical stage 0/I, cII, cIII, and cIV were 0% (95% confidence interval [CI]: 0%, 0.8%), 1.3% (95% CI: 0.4%, 3.3%), 4.4% (95% CI: 3.0%, 6.1%), and 43.3% (95% CI: 36.8%, 49.9%), respectively. The corresponding FRRs were 5.7% (95% CI: 3.8%, 8.2%), 2.9% (95% CI: 1.3%, 5.5%), 6.7% (95% CI: 5.0%, 8.8%), and 6.1% (95% CI: 3.4%, 10.0%), respectively. The proportions of patients with occult metastasis were 0% (95% CI: 0%, 0.8%), 3.3% (95% CI: 1.6%, 5.9%), 1.5% (95% CI: 0.8%, 2.7%), and 6.1% (95% CI: 3.4%, 10.0%), respectively. The proportion of patients who underwent pulmonary metastasectomy was 0% (none of 474; 95% CI: 0%, 0.8%) for clinical stage 0/I tumors. Conclusion In clinical stages 0 and I, the diagnostic yield of staging contrast-enhanced chest CT in detecting thoracic metastasis was zero. For clinical stages II, III, and IV, contrast-enhanced chest CT as a baseline examination was helpful for the detection of thoracic metastasis and allowed for the possibility of a curative metastasectomy. There was no significant association between clinical stage and false-referral rate. © RSNA, 2018 Online supplemental material is available for this article.

Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. © RSNA, 2017 Online supplemental material is available for this article.

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.

Background/Aims: Helicobacter pylori eradication is recom-mended in patients with early gastric cancer. However, the possibility of spontaneous regression raises a question for clinicians about the need for “retesting” postoperative H. py-lori status. Methods: Patients who underwent curative gas-trectomy at Seoul National University Bundang Hospital and had a positive H. pylori status without eradication therapy at the time of gastric cancer diagnosis were prospectively enrolled in this study. H. pylori status and atrophic gastritis (AG) and intestinal metaplasia (IM) histologic status were as-sessed pre- and postoperatively. Results: One hundred forty patients (mean age, 59.0 years; 60.7% male) underwent subtotal gastrectomy with B-I (65.0%), B-II (27.1%), Roux-en-Y (4.3%), jejunal interposition (0.7%), or proximal gastrectomy (4.3%). Preoperative presence of AG (62.9%) and IM (72.9%) was confirmed. The mean period between surgery and the last endoscopic follow-up was 38.0±25.6 months. Of the 140 patients, 80 (57.1%) were found to be persistently posi-tive for H. pylori, and 60 (42.9%) showed spontaneous nega-tive conversion at least once during follow-up. Of these 60 patients, eight (13.3%) showed more complex postoperative dynamic changes between negative and positive results. The spontaneous negative conversion group showed a trend of having more postoperative IM compared to the persistent H. pylori group. Conclusions: A high percentage of spontaneous regression and complex dynamic changes in H. pylori status were observed after partial gastrectomy, especially in individ-uals with postoperative histological IM. It is better to consider postoperative eradication therapy after retesting for H. pylori. (Gut Liver 2017;11:209-215)

Importance Whether computed tomography (CT) radiation is truly carcinogenic remains controversial. Large epidemiological studies that purportedly showed an association between CT radiation and carcinogenesis were limited by confounding by indication and reverse causation, because the reasons for CT examination were unknown. Objective To measure the risk of hematologic malignant neoplasms associated with perioperative abdominopelvic CT radiation among patients who underwent appendectomy for acute appendicitis. Design, setting, and participants This nationwide population-based cohort study used the National Health Insurance Service claims database in South Korea to assess 825 820 patients who underwent appendectomy for appendicitis from January 1, 2005, to December 31, 2015, and had no underlying risk factors for cancer. Patients were divided into CT-exposed (n = 306 727) or CT-unexposed (n = 519 093) groups. The study was terminated on December 31, 2017, and data were analyzed from October 30, 2018, to September 27, 2020. Exposures Perioperative abdominopelvic CT examination from 7 days before to 7 days after appendectomy. Main outcomes and measures The primary outcome was the incidence rate ratio (IRR) of hematologic malignant neoplasms for both groups. The secondary outcomes were IRR of abdominopelvic organ cancers and IRR of all cancers. The lag period was 2 years for the primary outcome and 5 years for secondary outcomes. The IRRs were calculated using Poisson regression models with adjustment for age and sex. Results Among the study population of 825 820 patients (52.9% male; median age, 28 [interquartile range, 15-41] years), hematologic malignant neoplasms developed in 323 patients in the CT-exposed group during 1 486 518 person-years and 500 patients in the CT-unexposed group during 3 422 059 person-years. For all hematologic malignant neoplasms, the IRR for the CT-exposed vs CT-unexposed group was 1.26 (95% CI, 1.09-1.45; P = .002). In terms of individual categories of hematologic malignant neoplasms, the CT-exposed group had an elevated risk only for leukemia (IRR, 1.40 [98.75% CI, 1.04-1.87, adjusted by Bonferroni correction]; P = .005). There was no between-group difference in incidence rate of abdominopelvic organ cancers (IRR, 1.07 [95% CI, 1.00-1.15]; P = .06) and that of all cancers (IRR, 1.04 [95% CI, 0.99-1.09]; P = .14). Conclusions and relevance This study controlled for reverse causation bias by defining the reasons for CT scan, and findings suggest that abdominopelvic CT radiation is associated with a higher incidence of hematologic malignant neoplasms. Efforts should be continued for judicious use of CT examinations.

Aim To investigate the clinical characteristics and computed tomography (CT) findings of post-polypectomy coagulation syndrome (PPCS) and colonic perforation in patients who have undergone colonoscopic polypectomy. Materials and methods Through a hospital database search, 5542 adult patients (age >40 years) who had undergone colonoscopic polypectomy from January 2011 to November 2014 were identified. After identification of patients with PPCS and colonic perforation, two abdominal radiologists reviewed the CT images of the patients in consensus. Results Eight patients (0.14%) with PPCS and six patients (0.11%) with perforation were identified. Five patients were excluded for absence of CT examination, leaving four patients with PPCS and five patients with perforation included in the study. Three of the patients with perforation eventually underwent surgery, while all the patients with PPCS completely recovered with conservative management. On CT images, the involved colonic wall was longer and thicker in the PPCS group than in the perforation group. All four patients with PPCS showed a mural defect filled with fluid and stratified enhancement with surrounding infiltration. Two patients, who did not undergo surgery for perforation, did not show surrounding infiltration and fluid collection. Conclusion On CT images, PPCS shows severe mural thickening with a stratified enhancement pattern, a mural defect filled with fluid and surrounding infiltration in addition to absence of extraluminal air. In patients with perforation, absence of CT findings suggestive of surrounding inflammation or peritonitis would help in choosing non-surgical management.

Purpose To retrospectively compare ultrasound (US) and CT as the preoperative first-line imaging modality in terms of negative appendectomy rate (NAR) and appendiceal perforation rate (APR) in adolescents and adults with suspected appendicitis. Methods We included 2,030 patients in 11 sites who underwent appendectomy following US (n = 102) or CT (n = 1,928). Propensity-score (PS) adjusted and matched comparisons were conducted. Matching was performed with 1:1 and 1:3 ratios. Secondary analyses were performed by adding appendiceal perforation to PS model. Results The unadjusted NAR difference between the unmatched US and CT groups (8% [8/102] versus 3.8% [73/1,928]) was 4.1 percentage points (95% confidence interval, −1.2, –9.3; p = 0.133). The PS adjusted difference was 4.1 percentage points (−1.8, –10.0; p = 0.169). The differences after 1:1 (9% [8/94] versus 5% [5/94]) and 1:3 (9% [8/94] versus 3.0% [8/271]) matching were 3 (−4, –10, p = 0.39) and 5.6 (−0.4, –11.6, p = 0.069) percentage points, respectively. The unadjusted APR difference between the unmatched US and CT groups (22% [22/102] versus 23.8% [459/1,928]) was −2.2 percentage points (−10.4, –6.0; p = 0.59). The PS-adjusted difference was −5.2 percentage points (−13.3, –2.9; p = 0.21). The differences after 1:1 (19% [18/94] versus 24% [23/94]) and 1:3 (19% [18/94] versus 20.7% [56/271]) matching were −5 (−17, –6, p = 0.38) and −1.5 (−10.8, –7.8, p = 0.75) percentage points, respectively. Conclusions The use of US instead of CT may increase NAR but does not significantly affect APR. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound, 2016

Background There has been no comparative study of the long-term oncological outcomes of appendiceal cancer and colon cancer. We hypothesized that the oncological outcome is worse in appendiceal cancer because perforation is more frequent than in colon cancer. Methods Patients with stage I–III were selected from 5046 patients with appendiceal or colon cancer, between September 2001 and June 2010. The 5-year disease-free survival (DFS) was the primary endpoint. Multivariate analyses with Cox proportional hazards model for DFS and logistic regression model for perforation were conducted. A matching model was used to compensate for the heterogeneity between groups. Results The perforation rate was 44.7% in appendiceal cancer (n = 47), but 1.1% in colon cancer (n = 2828) ( p = 0.001). The 5-year DFS rate was lower in appendiceal cancer than in colon cancer (57.9% vs . 85.2%, p = 0.001; matching model, 54.2% vs . 78.4%, p = 0.038), with a higher rate of peritoneal seeding (25.5% vs . 2.5%, p = 0.001; matching model, 24.0% vs . 4.0%, p = 0.007). Multivariate Cox regression showed that appendiceal cancer was an independent prognostic factor for poor DFS (hazard ratio = 2.602, 95% confidence interval = 1.26–5.35, p = 0.009), and logistic regression confirmed that appendiceal cancer was the risk factor associated with perforation (odds ratio = 66.265, 95% confidence interval = 28.21–155.61, p = 0.001). Conclusions This study suggested that the long-term oncological outcomes are worse for appendiceal cancer than for colon cancer, attributed to higher perforation rate in appendiceal cancer.

Objective To survey care providers' willingness to use 2-mSv computed tomography (CT) in their usual practice for adolescents and young adults with suspected appendicitis. Materials and Methods An ethical committee approved this prospective study. We introduced 2-mSv CT in 20 hospitals through a pragmatic clinical trial. At the final phase of the trial, we invited 698 potentially-involved care providers in the survey regarding their willingness to use 2-mSv CT. Multivariable logistic regression analyses were performed to identify factors associated with willingness. Nine months after the completion of the trial patient recruitment, we surveyed whether the hospitals were using 2-mSv CT in usual practice. Results The analyses included responses from 579 participants (203 attendings and 376 trainees; 221 radiologists, 196 emergency physicians, and 162 surgeons). Regarding the willingness to immediately change their standard practice to 2-mSv CT, 158 (27.3%), 375 (64.8%), and 46 (7.9%) participants responded as “yes” (consistently), “partly” (selectively), and “no”, respectively. Willingness varied considerably across the hospitals, but only slightly across the participants' departments or job titles. Willingness was significantly associated with attendings (p = 0.004), intention to maintain the dedicated appendiceal CT protocol (p < 0.001), belief in compelling evidence on the carcinogenic risk of conventional-dose CT radiation (p = 0.028), and hospitals having more than 1000 beds (p = 0.031). Fourteen of the 20 hospitals kept using 2-mSv appendiceal CT in usual practice after the trial. Conclusion Despite the extensive efforts over the years of this clinical trial, many care providers were willing to use 2-mSv CT selectively or not willing to use.

Purpose This study evaluated the oncologic impact of obesity, as determined by body mass index (BMI), in patients who underwent laparoscopic surgery for rectal cancer. Methods The records of 483 patients with stage I-III rectal cancer who underwent laparoscopic surgery between June 2003 and December 2011 were reviewed. A matching model based on BMI was constructed to balance obese and nonobese patients. Cox hazard regression models for overall survival (OS) and disease-free survival (DFS) were used for multivariate analyses. Additional analysis using visceral fat area (VFA) measurement was performed for matched patients. The threshold for obesity was BMI ≥ 25 kg/m2 or VFA ≥ 130 cm2. Results The score matching model yielded 119 patients with a BMI ≥ 25 kg/m2 (the obese group) and 119 patients with a BMI < 25 kg/m2 (the nonobese group). Surgical outcomes including operation time, estimated blood loss, nil per os periods, and length of hospital stay did not differ between the obese and the nonobese group. The retrieved lymph node numbers and pathologic CRM positive rate were also similar in between the 2 groups. After a median follow-up of 48 months (range, 3-126 months), OS and DFS rates were similar between the 2 groups. A tumor location-adjusted model for overall surgical complications showed that a BMI ≥ 25 kg/m2 were not risk factors. Multivariable analyses for OS and DFS showed no significant association with a BMI ≥ 25 kg/m2. Conclusion Obesity was not associated with long-term oncologic outcomes in patients undergoing laparoscopic surgery for rectal cancer in the Asian population.

Objective Use of computed tomography (CT) continues to increase, but the relatively high radiation doses associated with CT have raised health concerns such as future risk of cancer. We investigated the level of awareness regarding radiation doses and possible risks associated with CT in medical personnel (MP). Methods This study was conducted from April to May 2012 and included physicians and nurses who worked in the emergency department of 17 training hospitals. The questionnaire included measurement of the effect of CT or radiography on health using a 10-point numerical rating scale, estimation of the radiation dose of one abdominal CT scan compared with one chest radiograph, and perception of the increased lifetime risk of cancer associated with CT. Results A total of 354 MP participated in this study: 142 nurses, 87 interns, 86 residents, and 39 specialists. Interns were less aware of the effects of CT or radiography on health than other physicians or nurses (mean ±SD of 4.8 ±2.7, 5.9 ±2.7, 6.1 ±2.7, and 6.0 ±2.2 for interns, residents, specialists, and nurses, respectively; P

To systematically explore the lowest reasonably achievable radiation dose for appendiceal CT using an iterative reconstruction (IR) in young adults. We prospectively included 30 patients who underwent 2.0-mSv CT for suspected appendicitis. From the helical projection data, 1.5-, 1.0- and 0.5-mSv CTs were generated using a low-dose simulation tool and the knowledge-based IR. We performed step-wise non-inferiority tests sequentially comparing 2.0-mSv CT with each of 1.5-, 1.0- and 0.5-mSv CT, with a predetermined non-inferiority margin of 0.06. The primary end point was the pooled area under the receiver-operating-characteristic curve (AUC) for three abdominal and three non-abdominal radiologists. For the abdominal radiologists, the non-inferiorities of 1.5-, 1.0- and 0.5-mSv CT to 2.0-mSv CT were sequentially accepted [pooled AUC difference: 2.0 vs. 0.5 mSv, 0.017 (95% CI: -0.016, 0.050)]. For the non-abdominal radiologists, the non-inferiorities of 1.5- and 1.0-mSv CT were accepted; however, the non-inferiority of 0.5-mSv CT could not be proved [pooled AUC difference: 2.0 vs. 1.0 mSv, -0.017 (-0.070, 0.035) and 2.0 vs. 0.5 mSv, 0.045 (-0.071, 0.161)]. The 1.0-mSv appendiceal CT was non-inferior to 2.0-mSv CT in terms of diagnostic performance for both abdominal and non-abdominal radiologists; 0.5-mSv appendiceal CT was non-inferior only for abdominal radiologists. • For both abdominal and non-abdominal radiologists, 1.0-mSv appendiceal CT could be feasible. • The 0.5-mSv CT was non-inferior to 2.0-mSv CT only for expert abdominal radiologists. • Reader experience is an important factor affecting diagnostic impairment by low-dose CT.

The clinical efficacy of gadoxetic acid-enhanced liver MRI as a routine preoperative procedure for all patients with colorectal cancer remains unclear.The purpose of this study was to evaluate the efficacy of preoperative gadoxetic acid-enhanced liver MRI for the diagnosis of liver metastasis in patients with colorectal cancer.This was a retrospective analysis from a prospective cohort database.All of the patients were from a subspecialty practice at a tertiary referral hospital.Patients who received preoperative gadoxetic acid-enhanced liver MRI after CT and attempted curative surgery for colorectal cancer were included.The number of equivocal hepatic lesions based on CT and gadoxetic acid-enhanced liver MRI and diagnostic use of the gadoxetic acid-enhanced liver MRI were measured.We reviewed the records of 690 patients with colorectal cancer. Equivocal hepatic lesions were present in 17.2% of patients based on CT and in 4.5% based on gadoxetic acid-enhanced liver MRI. Among 496 patients with no liver metastasis based on CT, gadoxetic acid-enhanced liver MRI detected equivocal lesions in 15 patients and metastasis in 3 patients. Among 119 patients who had equivocal liver lesions on CT, gadoxetic acid-enhanced liver MRI indicated hepatic lesions in 103 patients (86.6%), including 90 with no metastasis and 13 with metastasis. Among 75 patients who had liver metastasis on CT, gadoxetic acid-enhanced liver MRI indicated that the hepatic lesions in 2 patients were benign, in contrast to CT findings. The initial surgical plans for hepatic lesions according to CT were changed in 17 patients (3%) after gadoxetic acid-enhanced liver MRI.This study was limited by its retrospective design.The clinical efficacy of gadoxetic acid-enhanced liver MRI as a routine preoperative procedure for all patients with colorectal cancer is low, in spite of its high diagnostic value for detecting liver metastasis. However, this study showed gadoxetic acid-enhanced liver MRI was helpful in characterizing equivocal hepatic lesions identified in CT and could lead to change in treatment plans for some patients. See Video Abstract at http://links.lww.com/DCR/A420.

Purpose To evaluate the association of computed tomography (CT) texture features of locally advanced rectal cancer with neoadjuvant chemoradiotherapy (CRT) response and disease-free survival (DFS). Methods and findings The institutional review board approved this retrospective study. 95 patients who received neoadjuvant CRT, followed by surgery, for locally advanced rectal cancer were included. Texture features (entropy, uniformity, kurtosis, skewness, and standard deviation) were assessed in pretreatment CT images and obtained without filtration and with Laplacian of Gaussian spatial filter of various filter values (1.0, 1.5, 2.0, and 2.5). Dworak pathologic grading was used for treatment response assessment. Independent t-test was used to compare each texture feature between the treatment responder and non-responder groups. DFS was assessed with Kaplan-Meier method, and differences were compared with log-rank test. Cox proportional hazards models were constructed to predict prognosis based on stage, age, and each texture feature. Treatment responders (n = 32) showed significantly lower entropy, higher uniformity, and lower standard deviation in no filtration, fine (1.0), and medium (1.5) filter values. Entropy, uniformity, and standard deviation without filtration showed significant difference in DFS in Kaplan-Meier analysis (P = 0.015, 0.025, and 0.038). Homogeneous texture features (≤ 6.7 for entropy, > 0.0118 for uniformity, and ≤ 28.06 for standard deviation) were associated with higher DFS. Entropy, uniformity, and standard deviation were independent texture features in predicting DFS (P = 0.017, 0.03, and 0.036). Conclusions Homogeneous texture features are associated with better neoadjuvant CRT response and higher DFS in patients with locally advanced rectal cancer.

Objective To retrospectively determine the sensitivity of preoperative CT in the detection of small (≤ 10 mm) colorectal liver metastasis (CRLM) nodules in patients undergoing liver resection. Methods The institutional review board approved the study and waived informed consent. We included 461 pathologically confirmed CRLM nodules in 211 patients (including 71 women; mean age, 66.4 years) who underwent 229 liver resections following abdominal CT. Prior to 163 resections, gadoxetic acid-enhanced liver MR imaging was also performed. Nodules were matched between pathology reports and prospective CT reports following a predefined algorithm. Per-nodule sensitivity of CT was calculated by nodule-size category. Generalized estimating equations were used to adjust for within-case correlation. Results Fourteen nodule sizes were missing in the pathology report. Nodules of 1–5 mm and 6–10 mm accounted for 8.1% (n = 36) and 23.5% (n = 105) of the remaining 447 nodules, and the number of nodules gradually decreased as nodule size increased beyond 10 mm. The overall sensitivity of CT was 81.2% (95% confidence interval, 77.1%, 85.2%; 365/461). The sensitivity was 8% (0%, 17%; 3/36), 55% (45%, 65%; 59/105), 91%, 95%, and 100% for nodules of 1–5 mm, 6–10 mm, 11–15 mm, 16–20 mm, and >20 mm, respectively. The nodule-size distribution was similar between resections undergoing gadoxetic acid-enhanced MR imaging and those not undergoing the MR imaging. Conclusion CT has limited sensitivity for nodules of ≤ 10 mm and particularly of ≤ 5 mm.

The purpose of this study was to simulate a mobile consultation in patients with inconclusive diagnosis of appendicitis made by on-call radiologists, as well as to measure the diagnostic confidence and performance of the mobile consultation.Two off-site abdominal radiologists interpreted the CT images from 68 patients (including 29 patients with confirmed appendicitis) on a smart-phone for whom the preliminary CT reports by 25 in-house on-call radiologists were inconclusive. The smartphone readings were compared with the preliminary reports by on-call radiologists and with the original final reports by in-house abdominal radiologists. Heat maps, kappa statistics, Wilcoxon signed-rank tests, and ROC curves were used for data analysis.The heat maps and kappa statistics showed that the smartphone readings were more similar to the final reports than to the preliminary reports. In diagnosing or ruling out appendicitis, the smartphone readings were more confident than the preliminary reports (p ≤ 0.01) and did not significantly differ in diagnostic confidence from the final reports (p ≥ 0.19). The AUCs of the smartphone readings (0.91 and 0.92) did not differ significantly from those of the preliminary (0.85) or final (0.97) reports (p ≥ 0.09).With the given study sample, the diagnostic performance of the off-site smartphone readings did not differ significantly from that of the in-house preliminary reports. However, the smartphone readings provided higher diagnostic confidence than the preliminary reports.

Aims/Introduction We sought to determine the association between change in fasting plasma glucose (FPG) and levels of liver enzymes, such as aspartate transaminase, alanine transaminase and gamma-glutamyltransferase, from health examinations. Materials and Methods A total of 9,393 health screen examinees with no evidence of viral hepatitis, liver diseases, abnormal liver function and diabetes in their past disease history were enrolled in the present study. All the participants underwent three health examinations. Group 1 and 4 were stationary groups of those with normal liver enzyme levels in the first and second health examinations (G1), and abnormal liver enzyme levels in the first and second health check-up (G4). Groups 2 and 3 were altered groups of those with abnormal liver enzyme levels in the first health examination, which became normal in the second health examination (G2), and from a normal liver enzymes level to an abnormal liver enzymes level (G3). Results FPG levels were elevated in male participants (P

ObjectivesThis study aims to identify an association between potential risk factors and risk of hematological malignancies, especially for Non-Hodgkin’s Lymphoma (NHL) and leukemia, among Korean semiconductor workers.MethodsWe collected 54 cases who ever worked over 30 days at a Korean semiconductor manufacturing company and were diagnosed as NHL (ICD-10 codes: C82–C85) and leukemia (C91–C95) from January 1 st 1998 to December 31 st 2017. A total of 324 controls, frequency matched by age and sex (1:6 ratios) with no diagnosis of hematological malignancies, were randomly selected. The information on work history, occupational exposure and medical examination data was also collected for the study analysis. Multivariable logistic regression analyses were performed to estimate odds ratios (ORs) after adjusting age, sex, education, employment year, smoking, alcohol and body mass index.ResultsNo significant association between hematological malignancies and occupational risk factors, including job title, cleanroom work and occupational exposures, was observed. As for leukemia, however, ORs were significantly increased by natural immunity to hepatitis B virus (HBV) [HBsAg(-), HBsAb(+), HBcAb(+)] (OR=11.92, 95% confidential interval 1.05–135.89) and a past or current (ever) HBV infection [HBsAg(+/-), HBsAb(+/-), HBcAb(+)] (6.52, 1.51–28.10). Furthermore, ORs for NHL were also significantly increased by insufficient serum 25-hydroxyvitamin D [25(OH)D] (12–20 ng/mL) (10.67, 1.27–89.53) and deficient 25(OH)D levels (ConclusionsRisk of hematological malignancies was not associated with occupational risk factors but significantly elevated by two factors, such as HBV infection and insufficient or deficient 25(OH)D level. A longitudinal cohort study is needed to confirm the association between these risk factors and cancers.

Background & aimsElastography point quantification is a convenient method for measuring liver stiffness. It can be performed simultaneously with conventional ultrasonography. This study aimed to evaluate its diagnostic performance for assessing hepatic fibrosis in patients with autoimmune liver disease (AILD), including autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC).MethodsThe diagnostic performance of elastography point quantification (ElastPQ) was evaluated and compared with that of serum fibrosis markers, including the aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4), using the receiver operating characteristics analysis with histologic evaluation as the reference standard.ResultsIn 49 AIH patients, sensitivity and specificity of ElastPQ were 93.6% and 44.4%, respectively, for significant fibrosis (≥ F2, cutoff 4.47 kPa), and 63.6% and 86.8% for cirrhosis (F4, cutoff 9.28 kPa). In 41 PBC patients, they were 81.8% and 73.3%, respectively, for significant fibrosis (≥ F2, cutoff 5.56 kPa), and 100% and 81.6%, respectively, for advanced fibrosis (≥ F3, cutoff 6.04 kPa). The areas under the receiver operating characteristic curves of ElastPQ for significant fibrosis (0.77, 95% CI 0.67-0.86) and cirrhosis (0.81, 95% CI 0.65-0.96) were higher than those of APRI and FIB-4 in AILD patients. According to the multivariable analysis, histological activity, steatosis, and body max index (BMI) were not significant factors that influenced the result of ElastPQ.ConclusionsElastPQ exhibited better diagnostic performance-without the influence of confounding factors-for assessing hepatic fibrosis in AILD patients than serum fibrosis markers.

Objective To survey care providers' preference between structured reporting (SR) and free-text reporting (FTR) for appendiceal computed tomography (CT) in adolescents and young adults. Materials and methods An ethical committee approved this prospective study. The requirement for participant consent was waived. We distributed the Likert scale-based SR form delivering the likelihood of appendicitis across 20 hospitals through a large clinical trial. In the final phase of the trial, we invited 706 potential care providers to participate in an online survey. The survey questions included usefulness in patient management, communicating the likelihood of appendicitis, convenience, style and format, and overall preference. Logistic regression analysis was performed for the overall preference. Three months after the completion of the trial, we checked if the use of the SR was sustained. Results Responses were analyzed from 594 participants (175 attendings and 419 trainees; 225 radiologists, 207 emergency physicians, and 162 surgeons). For each question, 47.3-64.8% of the participants preferred SR, 13.1-32.7% preferred FTR, and the remaining had no preference. The overall preference varied considerably across the hospitals, but slightly across the departments or job positions. The overall preference for SR over FTR was significantly associated with attendings, SR experience for appendiceal CT, hospitals with small appendectomy volume, and hospitals enrolling more patients in the trial. Five hospitals continued using the SR in usual care after the trial. Conclusion Overall, the care providers preferred SR to FTR. Further investigation into the sustained use of the SR is needed.

To explore the potential of high-resolution magic angle spinning (HRMAS) 1H nuclear magnetic resonance (NMR) spectroscopy for differentiation and metabolite characterization of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM), we prospectively included 21 pathologically confirmed malignant hepatic tumors (8 HCC and 13 CRLM) and 26 non-tumorous hepatic parenchyma from 26 patients who underwent hepatic tumor resection. Using intact tissue samples obtained during surgery, HRMAS 1H NMR spectroscopy was performed at 11.7 T. All observable metabolite signals were acquired using a water-presaturated standard one-dimensional Carr–Purcell–Meiboom–Gill sequence. Metabolomic profiles contributing to the differentiation of HCC and CRLM and of each tumor and non-tumorous hepatic parenchyma were represented by orthogonal partial least squares discriminant analysis (OPLS-DA) and loading plots. Metabolite intensity normalized by total spectral intensities in both tumors was compared using student’s t tests. OPLS-DA and loading plots demonstrated good separation between tumors and non-tumorous hepatic parenchyma. The metabolomic characteristics of HCC showed separation from those of CRLMs according to OPLS-DA. Compared with CRLM, HCC showed significantly elevated levels of glucose (P < 0.01) and sn-Glycero-3-phosphocholine (P < 0.01), and decreased levels of hypoxanthine (P = 0.04). HCC and CRLM could be differentiated by the metabolic profile using HRMAS 1H NMR spectroscopy.

We aimed to improve diagnostic accuracy of (18)F-fluoro-2-deoxyglucose (FDG) PET/CT for gastric cancer with water gastric inflation.44 gastric cancer patients (M:F=30:14, age ± std=62.1 ± 14.5 y) were enrolled before surgery. Fifty minutes after injection of FDG (0.14 mCi/kg body weight), whole body PET/CT was performed first and then regional PET/CT over gastric area was obtained 80 min post FDG injection after water gastric inflation. Diagnostic accuracies for loco-regional lesions were compared between whole body and regional PET/CT.48 primary tumors (23 EGC and 25 AGC) and 348 LN stations (61 metastatic and 287 benign) in 44 patients were investigated. Primary tumor sensitivity of whole body PET/CT (50%=24/48) was significantly improved by regional PET/CT (75%=36/48, p0.005). Sensitivity of whole body PET/CT (24.6%=15/61) for LN metastasis was also significantly improved by regional PET/CT (36.1%=22/61, p0.01), whereas specificity of whole body PET/CT (99.3%=285/287) was not compromised by regional PET/CT (98.3%=282/287, p0.05). Higher primary tumor FDG uptake in regional PET/CT indicated shorter progress-free survival (p=0.0003).Diagnostic accuracy of whole body PET/CT for loco-regional disease of gastric cancer could be significantly improved by regional PET/CT after water gastric inflation and prognosis could be effectively predicted by primary tumor FDG uptake in regional PET/CT.

To compare radiologists’ diagnostic performance and confidence, and subjective image quality between filtered back projection (FBP) and iterative reconstruction (IR) at 2-mSv appendiceal CT. The institutional review board approved this retrospective study and waived the requirement for informed consent. We included 107 adolescents and young adults (age, 29.8 ± 8.5 years; 64 females) undergoing 2-mSv CT for suspected appendicitis. Appendicitis was pathologically confirmed in 42 patients. Seven readers with different experience levels independently reviewed the CT images reconstructed using FBP and IR (iDose4, Philips). They rated both the likelihood of appendicitis and subjective image quality on 5-point Likert scales. Diagnostic confidence was assessed using the likelihood of appendicitis, proportion of indeterminate interpretations, and 3-point normal appendix visualization score. We used receiver operating characteristic analyses, Wilcoxon’s signed-rank tests, and McNemar’s tests. The pooled area under the receiver operating characteristic curve (AUC) was 0.96 for both FBP and IR (95% CI for the difference, −0.02, 0.02; P = 0.73). The AUC difference was not significant in any of the individual readers (P ≥ 0.21). For the majority of the readers, the diagnostic confidence was not significantly different between the two reconstruction methods. Subjective image quality tended to be higher with IR for all readers (P ≤ 0.70), showing significant differences for four readers (P ≤ 0.040). When diagnosing appendicitis at 2-mSv CT in adolescents and young adults, FBP and IR were comparable in radiologists’ diagnostic performance and confidence while IR exhibited higher subjective image quality than FBP.

To compare low and standard radiation doses in intravenous contrast material-enhanced abdominal computed tomography (CT) for the diagnosis of acute appendicitis in young adults.The institutional review board approved this retrospective study and waived informed consent. The study included 257 patients (age range, 15-40 years) who underwent CT for suspected appendicitis performed by using a low radiation dose (n = 125) or a standard radiation dose (n = 132). Receiver operating characteristic (ROC) analysis, Fisher exact tests, and Mann-Whitney U tests were used to compare the diagnosis of appendicitis and diagnostic confidence as recorded in prospective CT reports between the two groups.For 55 low-radiation-dose (median dose-length product, 122 mGy · cm) and 44 standard-dose (median dose-length product, 544 mGy · cm) examinations, one of two abdominal radiologists made primary reports that served as final reports. For the remaining examinations, on-call radiologists with differing levels of experience issued preliminary reports and the two abdominal radiologists then provided final reports. In the primary reports, the low- and standard-dose CT groups did not significantly differ in area under the ROC curve (0.96 vs 0.97, P = .76), sensitivity (90% [38 of 42] vs 89% [47 of 53], P.99), or specificity (92% [76 of 83] vs 94% [74 of 79], P = .74) in the diagnosis of appendicitis. There was also no significant difference between the two groups in the confidence level when diagnosing (P = .71) or excluding (P = .20) appendicitis in the primary reports. Similar results were observed for the final reports. The two dose groups also did not significantly differ in terms of appendiceal visualization, diagnosis of appendiceal perforation, or sensitivity for alternative diagnoses.Low-dose CT may have comparable diagnostic performance to standard-dose CT for the diagnosis of appendicitis in young adults.

A problem frequently encountered in the use of drainage catheters is that thrombus deposition tends to clog the drainage catheters, which destroy the efficacy of the device. In this study, a new heparin-releasing drainage catheter for inhibition of thrombus formation was proposed. The heparin-deoxycholic acid (heparin-DOCA) conjugate in the polyurethane solution was introduced to the drainage catheters using a simple casting method. From the results, the internal thickness of the coated drainage catheter was 15 μm and the coated surface of the catheter was even without defects. The pressures of the coated catheter measured at 7, 10, and 14 days were 10.8 ± 6.08, 25.0 ± 9.17, and 29.5 ± 12.02 mmHg, respectively. These values are relatively lower than the value of the bare catheter, showing that the pressure value of the bare catheter at 14 days was 198.5 ± 16.25 mmHg. This can be explained by the fact that the heparin-DOCA was released effectively from the catheter more than 2 weeks after inserting the catheter, which prevented thrombus deposition or fibrin clotting. In conclusion, the heparin release system is more effective for inhibiting thrombus formation than heparin-immobilized system. Open image in new window

Objective This study was conducted to compare the diagnostic accuracy for acute appendicitis between emergency medicine residents (EMRs) and surgical residents (SRs). Methods We conducted a prospective cohort study of adult patients with right lower quadrant pain. Each patient was evaluated by an EMR and an SR, and physicians predicted the probability of appendicitis into 4 groups from highest (group 1) to lowest (group 4). The diagnostic accuracies of EMR and SR for the diagnosis of appendicitis were compared by constructing receiver operating characteristics curves. In each case, an Alvarado score was calculated and a computed tomography (CT) scan of the abdomen and pelvis was performed, and their diagnostic accuracies were also compared with the predicted probabilities. Results Of a total 191 patients, 120 underwent surgery, and the negative appendectomy rate was 6.8%. There was a significant correlation between the predicted probabilities of EMR and SR. The areas under the curve for EMR and SR were 0.698 and 0.657, which were not statistically different. The areas under the curve of the Alvarado score and the CT were 0.735 and 0.978, respectively. The diagnostic accuracy of the CT scan was significantly higher than those of the Alvarado score and the resident-predicted probabilities. Conclusion In patients with right lower quadrant abdominal pain who have already been evaluated by EMR, consultation evaluation by SR does not appear to improve clinical diagnostic accuracy, and routine performance of CT before surgical consultation should be considered for these patients.

Background/Aims There has been a controversy regarding the usefulness of biofeedback therapy for functional constipation or fecal incontinence. This study was performed to investigate the long-term clinical efficacy of biofeedback therapy. Methods Sixty-four patients with constipation or fecal incontinence received biofeedback therapy for 4 weeks. Symptom improvements were evaluated immediately after the completion of biofeedback therapy and during the follow-up period of about 12 to 64 months. Results Twenty-five patients in the constipation group [mean age of 52.1 years, 16 men (64.0%)] received 6.2 sessions of biofeedback therapy. Improvement of constipation after the completion of biofeedback therapy was as follows: major response (or improvement) in 3 patients (12.0%), fair in 6 (24.0%), minor in 11 (44.0%) and none in 5 (20.0%). Among 9 patients who showed major or fair improvement, 8 patients (88.9%) maintained the symptom improvement through the long term follow-up periods. Thirty-nine patients in the fecal incontinence group [59.7 years old, 15 men (38.5%)] received 6.8 sessions of biofeedback therapy. Improvement of incontinence after the completion of biofeedback therapy was as follows: major improvement in 6 patients (15.4%), fair in 14 (35.9%), minor in 14 (35.9%), and none in 5 (12.8%). All 11 patients with major or fair improvement maintained the symptom improvement to the end of follow-up periods. Conclusions Symptom improvements after biofeedback therapy were disappointing in both the constipation and incontinence group. However, when the symptom improvements were classified as major or fair, the improvements continued for at least a year.

To prospectively evaluate the technical feasibility of percutaneous real-time contrast-enhanced ultrasound (CEUS) guided biopsy of focal hepatic lesions that are not confidently localised on B-mode US.The study included 44 patients (mean age, 61.3 years) whose biopsy target could not be confidently localised on B-mode US performed by two independent radiologists. Biopsy was attempted under the guidance of both CEUS and B-mode US simultaneously displayed on a single monitor. Final diagnosis was established based on the pathological examination of the biopsy specimen as well as on clinical and radiological follow-up.The size and depth of the target lesions were 18.0 +/- 9.0 mm (mean +/- SD) and 41.8 +/- 17.2 mm respectively. Five patients with negative or indistinct CEUS findings did not undergo biopsy, while 39 patients completed the biopsy. In 38 of the 39 patients, the biopsy result was concordant with the final diagnosis. In the remaining one patient, the biopsy failed to prove metastasis. As there were six cases of technical failure, the technical success rate was 86% (38/44). The sensitivity in diagnosing malignancy was 88% (30/34).Real-time CEUS-guided biopsy is technically feasible for hepatic focal lesions that are not confidently localised on B-mode US.

Background and Aim: The aim of this study was to determine the accuracy of endoscopic ultrasonography (EUS) and multidetector-row computed tomography (MDCT) for the locoregional staging of gastric cancer. EUS and computed tomography (CT) are valuable tools for the preoperative evaluation of gastric cancer. With the introduction of new therapeutic options and the recent improvements in CT technology, further evaluation of the diagnostic accuracy of EUS and MDCT is needed. Methods: In total, 277 patients who underwent EUS and MDCT, followed by gastrectomy or endoscopic resection at Bundang Hospital, Seoul National University, from July 2006 to April 2008, were analyzed. The results from the preoperative EUS and MDCT were compared to the postoperative pathological findings. Results: Among the 277 patients, the overall accuracy of EUS and MDCT for T staging was 74.7% and 76.9%, respectively. Among the 141 patients with visualized primary lesions on MDCT, the overall accuracy of EUS and MDCT for T staging was 61.7% and 63.8%, respectively. The overall accuracy for N staging was 66% and 62.8%, respectively. The performance of EUS and MDCT for large lesions and lesions at the cardia and angle had significantly lower accuracy than that of other groups. For EUS, the early gastric cancer lesions with ulcerative changes had significantly lower accuracy than those without ulcerative changes. Conclusions: For the preoperative assessment of individual T and N staging in patients with gastric cancer, the accuracy of MDCT was close to that of EUS. Both EUS and MDCT are useful complementary modalities for the locoregional staging of gastric cancer.

To determine the added value of multiplanar reformation (MPR) images combined with computed tomographic (CT) images in staging of T4 gastric cancers.The institutional review board approved this retrospective study and waived informed consent. One hundred forty-nine consecutive patients (99 men [age range, 33-85 years; mean age, 63.1 years] and 50 women [age range, 30-85 years; mean age, 57.1 years]; age range, 30-85 years; mean age, 61.1 years) with pathologically and/or surgically confirmed T3 (n = 110) or T4 tumors (n = 39), with invasion of the transverse colon or mesocolon (n = 23), pancreas (n = 16), diaphragm (n = 4), liver (n = 3), and/or spleen (n = 1) were included. Two experienced radiologists independently reviewed 4-mm-thick transverse CT images and, 10 weeks later, reviewed both transverse CT and additional coronal and sagittal MPR images to assess tumor invasion in each of the aforementioned five adjacent organs. Receiver operating characteristic (ROC) analyses and weighted kappa statistics were obtained to evaluate reader performance and agreement in identifying tumor invasion.With addition of MPR images, the area under the ROC curve (AUC) led to a significant increase in the prediction of adjacent organ invasion in per-organ analyses (0.88 vs 0.95 for reader 1 [P = .01], 0.88 vs 0.98 for reader 2 [P.001]) and identification of T4 tumors in per-patient analyses (0.79 vs 0.91 for reader 1 [P = .006], 0.78 vs 0.96 for reader 2 [P.001]). In the five analyzed organs, AUC was significantly increased in regard to invasion of the transverse colon or mesocolon and pancreas; separate analysis was not performed for the diaphragm, liver, and spleen because of the small number of true invasions. Interobserver agreement increased in per-organ (kappa = 0.43 vs 0.67) and per-patient (kappa = 0.42 vs 0.62) analyses.Adding MPR images to transverse CT images improves the capability for distinguishing T3 from T4 gastric cancer and prediction of adjacent organ invasion.http://radiology.rsnajnls.org/cgi/content/full/2502071872/DC1.

Introduction We have hypothesized that splenic flexure mobilization might be selectively undertaken in laparoscopic surgery (LAP) for rectal or sigmoid colon cancer. Patients and methods Oncologic clearance and postoperative morbidity were compared between 119 LAP patients and 145 open surgery (OS), all of whom were treated without splenic flexure mobilization. Results The operative time was similar in the 2 groups (P>0.05). The complication rate was lower after LAP than after OS (10.0% vs. 25.5%, P=0.043). Anastomotic leakage occurred in 1 patient after LAP. On a median 29-month follow-up, the local recurrence rates did not differ significantly between the 2 groups (0.9% for LAP vs. 2.6% for OS). Conclusions Laparoscopic procedures without routine splenic flexure mobilization do not increase postoperative morbidity or oncologic risk, as compared with OS. We suggest that laparoscopic rectal and sigmoid cancer resection can be safely conducted with selective splenic flexure mobilization.

We present here the radiological findings of a rare case of multiple focal nodular hyperplasia that was associated with portal vein atresia and portopulmonary hypertension in a young woman. This case illustrates and supports the pathophysiological hypotheses that were previously proposed for the coexistence of these three abnormalities.

The objective of our study was to prospectively evaluate the initial diagnostic performance and learning curve of a community of radiologists and residents in interpreting 2-mSv appendiceal CT.We included 46 attending radiologists and 153 radiology residents from 22 hospitals who completed an online training course of 30 2-mSv CT cases. Appendicitis was confirmed in 14 cases. Most of the readers had limited (≤ 10 cases, n = 32) or no (n = 118) prior experience with low-dose appendiceal CT. The order of cases was randomized for each reader. A multireader multicase ROC analysis was performed. Generalized estimating equations were used to model the learning curves in diagnostic performance.Diagnostic performance gradually improved with years of training. The average AUC was 0.94 (95% CI, 0.90-0.98), 0.92 (0.88-0.96), 0.90 (0.85-0.96), and 0.86 (0.80-0.92) for the attending radiologists, senior residents, 2nd-year residents, and 1st-year residents, respectively. We did not observe any notable intrareader learning curves over the training course of the 30 cases except a decrease in reading time. Diagnostic accuracy and sensitivity were significantly affected by the reader training level and prior overall experience with appendiceal CT but not by the prior specific experience with low-dose appendiceal CT.The learning curve is likely prolonged and forms gradually over years by overall radiology training and clinical experience in general rather than by experience with low-dose appendiceal CT specifically.

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.