Advanced analytics and artificial intelligence in gastrointestinal cancer: a systematic review of radiomics predicting response to treatment.

PURPOSE: Advanced medical image analytics is increasingly used to predict clinical outcome in patients diagnosed with gastrointestinal tumors. This review provides an overview on the value of radiomics in predicting response to treatment in patients with gastrointestinal tumors. METHODS: A systematic review was conducted, according to PRISMA guidelines. The protocol was prospectively registered (PROSPERO: CRD42019128408). PubMed, Embase, and Cochrane databases were searched. Original studies reporting on the value of radiomics in predicting response to treatment in patients with a gastrointestinal tumor were included. A narrative synthesis of results was conducted. Results were stratified by tumor type. Quality assessment of included studies was performed, according to the radiomics quality score. RESULTS: The comprehensive literature search identified 1360 unique studies, of which 60 articles were included for analysis. In 37 studies, radiomics models and individual radiomic features showed good predictive performance for response to treatment (area under the curve or accuracy > 0.75). Various strategies to construct predictive models were used. Internal validation of predictive models was often performed, while the majority of studies lacked external validation. None of the studies reported predictive models implemented in clinical practice. CONCLUSION: Radiomics is increasingly used to predict response to treatment in patients suffering from gastrointestinal cancer. This review demonstrates its great potential to help predict response to treatment and improve patient selection and early adjustment of treatment strategy in a non-invasive manner.

Small bowel imaging in celiac disease.

BACKGROUND: Modern small bowel imaging techniques allow detailed depiction of small-intestinal abnormalities. The role of these techniques in the investigation of celiac disease is increasing, especially in patients with suspected complicated celiac disease. KEY MESSAGES: In general, there is no need for radiological small bowel imaging in uncomplicated celiac disease. It is however important that clinicians and radiologists are aware of certain specific radiological findings that may suggest celiac disease, especially since celiac disease is often not considered in adult patients, and small bowel radiology may be performed before specific tests for celiac disease. Radiological abnormalities can be observed with both conventional small bowel radiology studies, like small bowel follow-through or double-contrast small bowel enteroclysis, and newer modalities, like computed tomography or magnetic resonance enterography or enteroclysis. These signs include a decreased number of jejunal folds, an increased number of ileal folds, small bowel dilatation, wall thickening and intussusception. Extraintestinal abnormalities include mesenteric lymphadenopathy, vascular changes and splenic atrophy. Abnormalities congruent with refractory celiac disease type II include a severe decrease in jejunal folds, infiltration of the mesenteric fat and thickening of the small bowel wall. Additionally, a severely decreased splenic volume may indicate complicated celiac disease. Malignant complications of celiac disease, such as enteropathy-associated T-cell lymphoma and small-intestinal adenocarcinoma, can be reliably investigated with cross-sectional enteroclysis techniques. CONCLUSIONS: Small bowel imaging and especially cross-sectional enteroclysis techniques are important extensions to the diagnostic workup of clinicians involved in the care of patients with celiac disease, especially those with suspected complicated disease.

Transcatheter CT arterial portography and CT hepatic arteriography for liver tumor visualization during percutaneous ablation.

PURPOSE: To evaluate the feasibility of combining transcatheter computed tomography (CT) arterial portography or transcatheter CT hepatic arteriography with percutaneous liver ablation for optimized and repeated tumor exposure. MATERIALS AND METHODS: Study participants were 20 patients (13 men and 7 women; mean age, 59.4 y; range, 40-76 y) with unresectable liver-only malignancies--14 with colorectal liver metastases (29 lesions), 5 with hepatocellular carcinoma (7 lesions), and 1 with intrahepatic cholangiocarcinoma (2 lesions)--that were obscure on nonenhanced CT. A catheter was placed within the superior mesenteric artery (CT arterial portography) or in the hepatic artery (CT hepatic arteriography). CT arterial portography or CT hepatic arteriography was repeatedly performed after injecting 30-60 mL 1:2 diluted contrast material to plan, guide, and evaluate ablation. The operator confidence levels and the liver-to-lesion attenuation differences were assessed as well as needle-to-target mismatch distance, technical success, and technique effectiveness after 3 months. RESULTS: Technical success rate was 100%; there were no major complications. Compared with conventional unenhanced CT, operator confidence increased significantly for CT arterial portography or CT hepatic arteriography cases (P < .001). The liver-to-lesion attenuation differences between unenhanced CT, contrast-enhanced CT, and CT arterial portography or CT hepatic arteriography were statistically significant (mean attenuation difference, 5 HU vs 28 HU vs 70 HU; P < .001). Mean needle-to-target mismatch distance was 2.4 mm ± 1.2 (range, 0-12.0 mm). Primary technique effectiveness at 3 months was 87% (33 of 38 lesions). CONCLUSIONS: In patients with technically unresectable liver-only malignancies, single-session CT arterial portography-guided or CT hepatic arteriography-guided percutaneous tumor ablation enables repeated contrast-enhanced imaging and real-time contrast-enhanced CT fluoroscopy and improves lesion conspicuity.

The pathogenesis of pneumothorax in Birt-Hogg-Dubé syndrome: a hypothesis.

The development and natural course of lung cysts in patients with Birt-Hogg-Dubé syndrome (BHD) is still unclear, and the relationship between lung cysts and pneumothorax is not fully clarified. Based on the follow-up results of thoracic imaging in six patients with BHD, we hypothesize that decreased potential for stretching of the cysts' wall and extensive contact with the visceral pleura are probably responsible for rupture of the cyst wall resulting in increased risk for pneumothorax.

The use of PET-MRI in the follow-up after radiofrequency- and microwave ablation of colorectal liver metastases.

BACKGROUND: Thermal ablation of colorectal liver metastases (CRLM) may result in local progression, which generally appear within a year of treatment. As the timely diagnosis of this progression allows potentially curative local treatment, an optimal follow-up imaging strategy is essential. PET-MRI is a one potential imaging modality, combining the advantages of PET and MRI. The aim of this study is evaluate fluorine-18 deoxyglucose positron emission tomography (FDG) PET-MRI as a modality for detection of local tumor progression during the first year following thermal ablation, as compared to the current standard, FDG PET-CT. The ability of FDG PET-MRI to detect new intrahepatic lesions, and the extent to which FDG PET-MRI alters clinical management, inter-observer variability and patient preference will also be included as secondary outcomes. METHODS/DESIGN: Twenty patients undergoing treatment with radiofrequency or microwave ablation for (recurrent) CRLM will be included in this prospective trial. During the first year of follow-up, patients will be scanned at the VU University Medical Center at 3-monthly intervals using a 4-phase liver CT, FDG PET-CT and FDG PET-MRI. Patients treated with chemotherapy <6 weeks prior to scanning or with a contra-indication for MRI will be excluded. MRI will be performed using both whole body imaging (mDixon) and dedicated liver sequences, including diffusion-weighted imaging, T1 in-phase and opposed-phase, T2 and dynamic contrast-enhanced imaging. The results of all modalities will be scored by 4 individual reviewers and inter-observer agreement will be determined. The reference standard will be histology or clinical follow-up. A questionnaire regarding patients' experience with both modalities will also be completed at the end of the follow-up year. DISCUSSION: Improved treatment options for local site recurrences following CRLM ablation mean that accurate post-ablation staging is becoming increasingly important. The combination of the sensitivity of MRI as a detection method for small intrahepatic lesions with the ability of FDG PET to visualize enhanced metabolism at the ablation site suggests that FDG PET-MRI could potentially improve the accuracy of (early) detection of progressive disease, and thus allow swifter and more effective decision-making regarding appropriate treatment. TRIAL REGISTRATION NUMBER: NCT01895673.

Prognostic value of total tumor volume in patients with colorectal liver metastases: A secondary analysis of the randomized CAIRO5 trial with external cohort validation.

BACKGROUND: This study aimed to assess the prognostic value of total tumor volume (TTV) for early recurrence (within 6 months) and overall survival (OS) in patients with colorectal liver metastases (CRLM), treated with induction systemic therapy followed by complete local treatment. METHODS: Patients with initially unresectable CRLM from the multicenter randomized phase 3 CAIRO5 trial (NCT02162563) who received induction systemic therapy followed by local treatment were included. Baseline TTV and change in TTV as response to systemic therapy were calculated using the CT scan before and the first after systemic treatment, and were assessed for their added prognostic value. The findings were validated in an external cohort of patients treated at a tertiary center. RESULTS: In total, 215 CAIRO5 patients were included. Baseline TTV and absolute change in TTV were significantly associated with early recurrence (P = 0.005 and P = 0.040, respectively) and OS in multivariable analyses (P = 0.024 and P = 0.006, respectively), whereas RECIST1.1 was not prognostic for early recurrence (P = 0.88) and OS (P = 0.35). In the validation cohort (n = 85), baseline TTV and absolute change in TTV remained prognostic for early recurrence (P = 0.041 and P = 0.021, respectively) and OS in multivariable analyses (P < 0.0001 and P = 0.012, respectively), and showed added prognostic value over conventional clinicopathological variables (increase C-statistic, 0.06; 95 % CI, 0.02 to 0.14; P = 0.008). CONCLUSION: Total tumor volume is strongly prognostic for early recurrence and OS in patients who underwent complete local treatment of initially unresectable CRLM, both in the CAIRO5 trial and the validation cohort. In contrast, RECIST1.1 did not show prognostic value for neither early recurrence nor OS.

Postpartum monitoring of retained placenta.Two cases of abnormally adherent placenta.

To save fertility, hysterectomy may be avoided with abnormal placental adherence by leaving the placenta in situ. Several reports support this strategy, but no reports are available on optimal follow-up strategies. We present two women with conservative treatment of placenta accreta and describe the prospective monitoring of the clinical course, placental regression, and recovery of the uterine anatomy using serial sonography, hysteroscopy and magnetic resonance imaging. There was no postpartum hemorrhage. Menstrual cyclicity resumed within 18 weeks. The human chorionic gonadotropin serum levels normalized within 10 weeks, whereas regression of placenta tissue was slow and continued up to nine months after delivery. In both cases placental remnants persisted; in one woman they were removed and uterine anatomy restored. She had a subsequent uneventful pregnancy afterwards. The presented systematic follow-up provides tools to monitor and treat other women in similar ways.

Comparison of MR enteroclysis with video capsule endoscopy in the investigation of small-intestinal disease.

PURPOSE: To evaluate the diagnostic accuracy of MR enteroclysis and to compare it to video capsule endoscopy (VCE) in the analysis of suspected small-bowel disease. METHODS: We performed a retrospective analysis of 77 patients who underwent both MR enteroclysis and VCE and compared the findings of these studies with the findings of enteroscopy, surgery, or with the results of clinical follow-up lasting ≥2 years. RESULTS: Findings included malignant neoplasms (n = 13), benign neoplasms (n = 10), refractory celiac disease (n = 4), Crohn's disease (n = 2) and miscellaneous conditions (n = 10). Specificity of MR enteroclysis was higher than that of VCE (0.97 vs. 0.84, P = 0.047), whereas sensitivity was similar (0.79 vs. 0.74, P = 0.591). In 2/32 (6.3%) patients with both negative VCE and negative MR enteroclysis a positive diagnosis was established, compared to 5/11 (45.5%) patients in whom VCE was positive and MR enteroclysis was negative (likelihood ratio 8.1; P = 0.004), 9/11 (81.8%) patients in whom MR enteroclysis was positive and VCE was negative (likelihood ratio 23.5; P < 0.0001), and all 23 patients in whom both VCE and MR enteroclysis showed abnormalities (likelihood ratio 60.8; P < 0.0001). CONCLUSIONS: VCE and MR enteroclysis are complementary modalities. In our study-population, MR enteroclysis was more specific than VCE, while both produced the same sensitivity.

Deep learning models for automatic tumor segmentation and total tumor volume assessment in patients with colorectal liver metastases.

BACKGROUND: We developed models for tumor segmentation to automate the assessment of total tumor volume (TTV) in patients with colorectal liver metastases (CRLM). METHODS: In this prospective cohort study, pre- and post-systemic treatment computed tomography (CT) scans of 259 patients with initially unresectable CRLM of the CAIRO5 trial (NCT02162563) were included. In total, 595 CT scans comprising 8,959 CRLM were divided into training (73%), validation (6.5%), and test sets (21%). Deep learning models were trained with ground truth segmentations of the liver and CRLM. TTV was calculated based on the CRLM segmentations. An external validation cohort was included, comprising 72 preoperative CT scans of patients with 112 resectable CRLM. Image segmentation evaluation metrics and intraclass correlation coefficient (ICC) were calculated. RESULTS: In the test set (122 CT scans), the autosegmentation models showed a global Dice similarity coefficient (DSC) of 0.96 (liver) and 0.86 (CRLM). The corresponding median per-case DSC was 0.96 (interquartile range [IQR] 0.95-0.96) and 0.80 (IQR 0.67-0.87). For tumor segmentation, the intersection-over-union, precision, and recall were 0.75, 0.89, and 0.84, respectively. An excellent agreement was observed between the reference and automatically computed TTV for the test set (ICC 0.98) and external validation cohort (ICC 0.98). In the external validation, the global DSC was 0.82 and the median per-case DSC was 0.60 (IQR 0.29-0.76) for tumor segmentation. CONCLUSIONS: Deep learning autosegmentation models were able to segment the liver and CRLM automatically and accurately in patients with initially unresectable CRLM, enabling automatic TTV assessment in such patients. RELEVANCE STATEMENT: Automatic segmentation enables the assessment of total tumor volume in patients with colorectal liver metastases, with a high potential of decreasing radiologist's workload and increasing accuracy and consistency. KEY POINTS: • Tumor response evaluation is time-consuming, manually performed, and ignores total tumor volume. • Automatic models can accurately segment tumors in patients with colorectal liver metastases. • Total tumor volume can be accurately calculated based on automatic segmentations.

Deep infiltrating endometriosis of the bowel: MR imaging as a method to predict muscular invasion.

PURPOSE: To evaluate magnetic resonance (MR) imaging morphologic- and signal intensity abnormalities of deep infiltrating endometriosis (DIE) of the bowel wall and to assess its value in predicting depth and extent of bowel wall infiltration. MATERIALS AND METHODS: This single-center study was performed in a tertiary referral center for endometriosis. All patients (n = 28) who underwent segmental bowel resection (2004-2010) were retrospectively studied. MR images were analyzed by two experienced readers independently (number of lesions, location, size, signal intensity, and depth of bowel wall infiltration) and this was correlated with histopathology. RESULTS: The sensitivity, specificity, positive and negative predictive values, and accuracy for diagnosis of endometriosis infiltrating the muscular layer of the bowel were 100%, 75%, 96%, 100%, and 96%, respectively. The inter-rater agreement was 0.84. "Fan shaped" configurations with hypointensity on T2- and T1-weighted imaging were characteristic for thickening of indigenous smooth muscle and smooth muscle hyperplasia at histopathology, as a consequence of infiltration by endometriosis. Thickening of the (sub)mucosa corresponded to edema with or without infiltration of endometriosis. CONCLUSION: MR imaging at 1.5 Tesla is useful to predict muscular infiltration of the bowel in endometriosis, whereas it is of limited value in diagnosis of (sub)mucosal infiltration.

MR enteroclysis in refractory celiac disease: proposal and validation of a severity scoring system.

PURPOSE: To determine magnetic resonance (MR) enteroclysis findings in patients with uncomplicated celiac disease (CD), refractory CD (RCD) type I, and RCD type II, to develop and validate a scoring system to identify patients with RCD II and to determine the diagnostic accuracy of MR enteroclysis to detect CD-related malignancies. MATERIALS AND METHODS: This study was performed with approval of the institutional review board. One radiologist blinded to clinical details retrospectively evaluated quantitative and qualitative criteria of 28 studies obtained in symptomatic patients with CD (uncomplicated CD, n = 10; RCD I, n = 8; RCD II, n = 10). A scoring system was developed by using parameters identified in multivariate analysis to be associated with RCD II, which two radiologists evaluated in a second group of 40 symptomatic patients with CD. Accuracy to detect malignancy was assessed in the total study group. Cumulative survival was evaluated in the total study group by using the Kaplan-Meier method. RESULTS: MR enteroclysis could not be used to discriminate between uncomplicated CD and RCD I. The presence of less than 10 folds per 5 cm jejunum, mesenteric fat infiltration, and bowel wall thickening were associated with RCD II. A positive MR score was defined as the presence of two or more of these features. In the validation group, the MR score was positive in 13 of 15 patients with RCD II (sensitivity, 0.87) and negative in 24 of 25 patients without RCD II (specificity, 0.96). The 5-year survival rate was 95% in patients with a negative MR score and 56% in patients with a positive MR score (P < .0001). MR enteroclysis helped to identify the presence of seven of eight malignancies and to diagnose absence of malignancy in 58 of 60 studies. CONCLUSION: MR enteroclysis can be used to investigate the presence of RCD II or malignancy in symptomatic patients with CD.

Survival Benefit of Repeat Local Treatment in Patients Suffering From Early Recurrence of Colorectal Cancer Liver Metastases.

BACKGROUND: A uniform treatment strategy for patients suffering from early recurrence after local treatment of CRLM is currently lacking. The aim of this observational cohort study was to assess the potential survival benefit of repeat local treatment compared to systemic therapy in patients suffering from early recurrence of CRLM. PATIENTS AND METHODS: Patients who developed recurrent CRLM within 12 months after initial local treatment with curative intent were retrospectively identified in Amsterdam University Medical Centers between 2009-2019. Differences in overall and progression-free survival among treatment strategies were assessed using multivariable Cox regression analyses. RESULTS: A total of 135 patients were included. Median overall survival of 41 months [range 4-135] was observed in patients who received repeat local treatment, consisting of upfront or repeat local treatment after neoadjuvant systemic therapy, compared to 24 months [range 1-55] in patients subjected to systemic therapy alone (adjusted HR = 0.42 [95%-CI: 0.25-0.72]; P = .002). Prolonged progression-free survival was observed after neoadjuvant systemic therapy followed by repeat local treatment, as compared to upfront repeat local treatment in patients with recurrent CRLM within 4 months following initial local treatment of CRLM (adjusted HR = 0.36 [95%-CI: 0.15-0.86]; P = .021). CONCLUSION: Patients with early recurrence of CRLM should be considered for repeat local treatment strategies. A multimodality approach, consisting of neoadjuvant systemic therapy followed by repeat local treatment, appeared favorable in patients with recurrence within 4 months following initial local treatment of CRLM.

KRAS A146 Mutations Are Associated With Distinct Clinical Behavior in Patients With Colorectal Liver Metastases.

Somatic KRAS mutations occur in approximately half of the patients with metastatic colorectal cancer (mCRC). Biologic tumor characteristics differ on the basis of the KRAS mutation variant. KRAS mutations are known to influence patient prognosis and are used as predictive biomarker for treatment decisions. This study examined clinical features of patients with mCRC with a somatic mutation in KRAS G12, G13, Q61, K117, or A146. METHODS: A total of 419 patients with colorectal cancer with initially unresectable liver-limited metastases, who participated in a multicenter prospective trial, were evaluated for tumor tissue KRAS mutation status. For the subgroup of patients who carried a KRAS mutation and were treated with bevacizumab and doublet or triplet chemotherapy (N = 156), pretreatment circulating tumor DNA levels were analyzed, and total tumor volume (TTV) was quantified on the pretreatment computed tomography images. RESULTS: Most patients carried a KRAS G12 mutation (N = 112), followed by mutations in G13 (N = 15), A146 (N = 12), Q61 (N = 9), and K117 (N = 5). High plasma circulating tumor DNA levels were observed for patients carrying a KRAS A146 mutation versus those with a KRAS G12 mutation, with median mutant allele frequencies of 48% versus 19%, respectively. Radiologic TTV revealed this difference to be associated with a higher tumor load in patients harboring a KRAS A146 mutation (median TTV 672 cm3 [A146] v 74 cm3 [G12], P = .036). Moreover, KRAS A146 mutation carriers showed inferior overall survival compared with patients with mutations in KRAS G12 (median 10.7 v 26.4 months; hazard ratio = 2.5; P = .003). CONCLUSION: Patients with mCRC with a KRAS A146 mutation represent a distinct molecular subgroup of patients with higher tumor burden and worse clinical outcomes, who might benefit from more intensive treatments. These results highlight the importance of testing colorectal cancer for all KRAS mutations in routine clinical care.

Thermal Ablation versus Stereotactic Ablative Body Radiotherapy to Treat Unresectable Colorectal Liver Metastases: A Comparative Analysis from the Prospective Amsterdam CORE Registry.

Thermal ablation and stereotactic ablative radiotherapy (SABR) are techniques to eradicate colorectal liver metastases (CRLM). This study compares the safety, efficacy and long-term oncological outcomes of these treatment methods. All prospectively registered patients (AmCORE registry) treated with thermal ablation or SABR alone for unresectable CRLM between 2007 and 2020 were analyzed using multivariate Cox-proportional hazard regression. In total 199 patients were included for analysis: 144 (400 CRLM) thermal ablation; 55 (69 CRLM) SABR. SABR patients were characterized by older age (p = 0.006), extrahepatic disease at diagnosis (p = 0.004) and larger tumors (p < 0.001). Thermal ablation patients were more likely to have synchronous disease, higher clinical risk scores (p = 0.030) and higher numbers of CRLMs treated (p < 0.001). Mortality was zero and morbidity low in both groups: no serious adverse events were recorded following SABR (n = 0/55) and nine (n = 9/144 [6.3%]; all CTCAE grade 3) after thermal ablation. SABR was associated with an inferior overall survival (OS) (median OS 53.0 months vs. 27.4 months; HR = 1.29, 95% CI 1.12-1.49; p = 0.003), local tumor progression-free survival (LTPFS) per-tumor (HR = 1.24, 95% CI 1.01-1.52; p = 0.044) and local control per-patient (HR = 1.57, 95% CI 1.20-2.04; p = 0.001) and per-tumor (HR = 1.89, 95% CI 1.44-2.49; p < 0.001). In this study thermal ablation was superior to SABR with regard to OS, LTPFS and local control, albeit at the cost of a limited risk of serious adverse events. Further studies are required to assess whether the worse outcomes following SABR were the effect of true differences in ablative treatment or a result of residual confounding.

The Prognostic Value of Total Tumor Volume Response Compared With RECIST1.1 in Patients With Initially Unresectable Colorectal Liver Metastases Undergoing Systemic Treatment.

Objectives: Compare total tumor volume (TTV) response after systemic treatment to Response Evaluation Criteria in Solid Tumors (RECIST1.1) and assess the prognostic value of TTV change and RECIST1.1 for recurrence-free survival (RFS) in patients with colorectal liver-only metastases (CRLM). Background: RECIST1.1 provides unidimensional criteria to evaluate tumor response to systemic therapy. Those criteria are accepted worldwide but are limited by interobserver variability and ignore potentially valuable information about TTV. Methods: Patients with initially unresectable CRLM receiving systemic treatment from the randomized, controlled CAIRO5 trial (NCT02162563) were included. TTV response was assessed using software specifically developed together with SAS analytics. Baseline and follow-up computed tomography (CT) scans were used to calculate RECIST1.1 and TTV response to systemic therapy. Different thresholds (10%, 20%, 40%) were used to define response of TTV as no standard currently exists. RFS was assessed in a subgroup of patients with secondarily resectable CRLM after induction treatment. Results: A total of 420 CT scans comprising 7820 CRLM in 210 patients were evaluated. In 30% to 50% (depending on chosen TTV threshold) of patients, discordance was observed between RECIST1.1 and TTV change. A TTV decrease of >40% was observed in 47 (22%) patients who had stable disease according to RECIST1.1. In 118 patients with secondarily resectable CRLM, RFS was shorter for patients with less than 10% TTV decrease compared with patients with more than 10% TTV decrease (P = 0.015), while RECIST1.1 was not prognostic (P = 0.821). Conclusions: TTV response assessment shows prognostic potential in the evaluation of systemic therapy response in patients with CRLM.

MR enteroclysis in the diagnosis of small-bowel neoplasms.

PURPOSE: To evaluate the diagnostic accuracy and interobserver variance of magnetic resonance (MR) enteroclysis in the diagnosis of small-bowel neoplasms, with small-bowel endoscopy, surgery, histopathologic analysis, and follow-up serving as standards of reference, and to identify MR enteroclysis characteristics capable of enabling discrimination between benign and malignant small-bowel neoplasms. MATERIALS AND METHODS: This study was performed in accordance with the guidelines of the institutional review board, and the requirement for informed consent was waived. MR enteroclysis studies of 91 patients (43 women, 48 men; age range, 18-83 years) were retrospectively evaluated by two radiologists blinded to clinical details. Only studies explicitly performed to investigate or exclude the presence of small-bowel neoplasms were included. Radiologic findings were compared with findings of double-balloon endoscopy (n = 45), surgery (n = 18), esophagogastroduodenoscopy (n = 3), ileocolonoscopy (n = 2), autopsy (n = 2), and clinical follow-up for more than 18 months (n = 21). Efficacy parameters were calculated with 95% confidence intervals. Tumor characteristics were compared with the Student t test and the Fisher exact test. RESULTS: Readers 1 and 2 interpreted 31 and 33 studies, respectively, as depicting a small-bowel neoplasm and 19 and 17 studies, respectively, as depicting small-bowel malignancy. In 32 patients, the presence of small-bowel neoplasm was confirmed. In 19 of these patients, the neoplasm was malignant. Sensitivity and specificity in the diagnosis of small-bowel neoplasms was 0.91 and 0.95, respectively, for reader 1 and 0.94 and 0.97, respectively, for reader 2; the kappa value was 0.95. Factors associated with malignancy were the presence of longer solitary nonpedunculated lesions, mesenteric fat infiltration, and enlarged mesenteric lymph nodes. CONCLUSION: Eighty-six of 91 studies were correctly interpreted, resulting in an overall diagnostic accuracy of 0.95 for MR enteroclysis in the detection of small-bowel neoplasms. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09090828/-/DC1.

Double-balloon endoscopy as the primary method for small-bowel video capsule endoscope retrieval.

BACKGROUND: Capsule retention in the small bowel is a known complication of small-bowel video capsule endoscopy. Surgery is the most frequently used method of capsule retrieval. OBJECTIVE: To determine the incidence and causes of capsule retention and to describe double-balloon endoscopy (DBE) as the primary technique used for capsule retrieval. DESIGN: Retrospective analysis of all video capsule studies was performed at our center, and evaluation of the outcome of DBE was the first method used to retrieve entrapped video capsules. SETTING: Tertiary referral center. PATIENTS: A total of 904 patients who underwent small-bowel video capsule endoscopy. INTERVENTIONS: Capsule retrieval by DBE. MAIN OUTCOME MEASUREMENTS: The number of patients in whom capsule retention occurred and the number of patients in whom an entrapped capsule could be retrieved by using DBE. RESULTS: Capsule retention occurred in 8 patients (incidence 0.88%; 95% CI, 0.41%-1.80%) and caused acute small-bowel obstruction in 6 patients. All retained capsules were successfully removed during DBE. Five patients underwent elective surgery to treat the underlying cause of capsule retention. One patient required emergency surgery because of multiple small-bowel perforations. LIMITATIONS: Retrospective design. CONCLUSIONS: In our series, the incidence of capsule retention was low. DBE is a reliable method for removing retained capsules and might prevent unnecessary surgery. If surgery is required, preoperative capsule retrieval allows preoperative diagnosis, adequate staging in case of malignancy, and optimal surgical planning.

Appearance of abdominal wall endometriosis on MR imaging.

OBJECTIVE: Abdominal wall endometriosis (AWE) is defined as endometrial tissue that is superficial to the peritoneum. AWE is often difficult to diagnose, mimicking a broad spectrum of diseases. The aim of this study was to describe the appearance of AWE on magnetic resonance (MR) imaging. METHODS: We present ten patients with AWE (12 lesions) in which MR imaging was used for diagnosis. MR imaging included T2-weighted imaging and T1-weighted imaging with fat suppression. To assess the value of diffusion-weighted imaging (DWI) in endometriosis, four patients underwent additional DWI. The apparent diffusion coefficient (ADC) was calculated using b values of 50, 400, 800 and 1,200 s/mm(2). RESULTS: In most cases, the lesion was located ventral or dorsal to the aponeurosis of the rectus oblique muscle (n = 6) or in the rectus abdominis (n = 5). MR of AWE lesions showed isointense or slightly hyperintense signal compared with muscle on T2-weighted images and showed isointense or slightly hyperintense signal compared with muscle on T1-weighted images with foci of high signal intensity, indicative of haemorrhage. The mean ADC value of AWE was 0.93 x 10(-3)/mm(2)/s. CONCLUSION: MR imaging seems to be useful in determining the location and depth of infiltration in surrounding tissue preoperatively.

The clinical suspicion of a leaking intrathoracic esophagogastric anastomosis: the role of CT imaging.

BACKGROUND: CT imaging is the primary diagnostic approach to assess the integrity of the intrathoracic anastomosis following Ivor Lewis esophagectomy. In the postoperative setting interpretation of CT findings, such as air and fluid collections, may be challenging. Establishment of a scoring system that incorporates CT findings to diagnose anastomotic leakage could assist radiologists and surgeons in the postoperative phase. METHODS: Consecutive patients who underwent a CT scan for a clinical suspicion of postoperative anastomotic leakage following Ivor Lewis esophagectomy between 2010 and 2016 in two medical centers were retrospectively included. Scans were excluded when oral contrast was not (correctly) administered. Acquired images were randomized and independently assessed by two experienced gastrointestinal radiologists, blinded for clinical information. For this study anastomotic leakage was defined as a visible defect during endoscopy or thoracotomy. RESULTS: A total of 80 patients had 101 CT scans, resulting in 32 scans with a confirmed anastomotic leak (25 patients). After multivariable backward stepwise logistic regression, a practical 5-point scoring system was developed, which included the following CT findings: presence of extraluminal oral contrast, air collection at the anastomotic site, fluid collection at the anastomotic site, pneumothorax and loculated pleural effusion. Patients with a score of ≥3 were considered at high risk for anastomotic leakage (positive predictive value: 83.3%), patients with scores <3 were considered at low risk for anastomotic leakage (negative predictive value: 84.4%). The scoring system showed a superior diagnostic performance compared to the original CT report and blinded interpretation of two radiologists. CONCLUSIONS: Our CT-based practical scoring system enables a standardized approach in CT assessment and could facilitate early recognition of anastomotic leakage in patients after Ivor Lewis esophagectomy.

Interobserver agreement between on-call radiology residents and radiology specialists in the diagnosis of pulmonary embolism using computed tomography pulmonary angiography.

OBJECTIVE: The objective of this study was to assess the interobserver agreement between on-call radiology residents and radiology specialists in the evaluation of pulmonary embolism (PE) using computed tomographic pulmonary angiography (CTPA). MATERIALS AND METHODS: Single center, prospective cohort study of 119 consecutive inpatients and outpatients with clinically suspected PE in whom CTPA was performed during out-of-office hours and weekends. The on-call radiology resident interpreted the CTPA for the presence of PE. An experienced radiology specialist, without knowledge of earlier reading, reviewed the CTPA the following morning. In discordant cases, a consensus reading was conducted. The radiology specialists' assessment and the consensus reading in case of discordance were considered as the gold standard. RESULTS: Five CTPA studies were excluded from the analysis. In the remaining cases, radiology residents and radiology specialists agreed on the interpretations of CTPAs (no PE vs PE present) in 106 (93%) of the 114 cases, with a kappa value of 0.84 (95% confidence interval, 0.74-0.95). The consensus reading equally disagreed with both radiology resident and radiology specialist in 8 (7%) of the 114 discordant cases. Seven out of 8 discordant cases had suboptimal scan quality. CONCLUSIONS: The assessment of CTPA in patients with suspected PE by radiology residents seems reliable during out-of-office hours.