Helical CT-enteroclysis in the detection of small-bowel tumours: a meta-analysis

Extremely rare mucinous adenocarcinoma of the small bowel causing bilateral metastatic Kukenberg tumors of the ovaries: A case report

RATIONALE

Small bowel adenocarcinoma (SBA) is an extremely rare tumor that is not fully understood, SBA accounts for less than 5% of gastrointestinal cancers, Krukenberg tumors account for a lower proportion of all ovarian tumors, close to 2%. Stomach is the most common primary site of Krukenberg tumor. The phenomenon of bilateral ovarian Kukenberg tumor caused by implantation and metastasis of small bowel cancer is extremely rare, with few literature reports and limited clinical diagnosis and treatment data. We present a case of a 55-year-old woman with bilateral Kukenberg's tumor caused by small bowel cancer implantation and share our views on the diagnosis and treatment of this case.

PATIENT CONCERNS

A 55-year-old woman presented with vaginal bleeding and persistent lower abdominal pain after fatigue 10 days ago. Pelvic ultrasound at a local hospital revealed 2 solid masses in her pelvis, and she came to our hospital for further diagnosis and treatment. The results of colonofiberscope examination and histopathological examination confirmed intramucosal adenocarcinoma in the small intestine.

DIAGNOSES

The results of colonofiberscope examination and histopathological examination confirmed intramucosal adenocarcinoma in the small intestine. Contrast-enhanced computed tomography showed multiple cystic space-occupying lesions in the pelvic cavity, and the possibility of ovarian tumor was considered.

INTERVENTIONS

Radical treatment of right half colon cancer and pelvic mass resection were performed under general anesthesia. Combined with intraoperative and postoperative pathological examination, the diagnosis was mucinous adenocarcinoma of the small intestine stage IV (pT4N1M1). Bilateral ovarian metastasis, metastatic cancer (3/19): lymph nodes around the small intestine (3/12), lymph nodes around the colon (0/7).

OUTCOMES

He is currently receiving chemotherapy, the chemotherapy regimen is XELOX regimen. The specific drugs were oxaliplatin and capecitabine.

LESSONS

SBA is often difficult to diagnose due to few specific symptoms and is usually detected at stage IV. Bilateral ovarian Kukenberg tumor caused by small bowel cancer implantation metastases is extremely rare, and clinicians must be vigilant for women with fewer specific symptoms of gastrointestinal discomfort and conduct further diagnostic studies to avoid delayed diagnosis and treatment.

Synchronous Multiple Primary Malignant Adenocarcinoma of the Descending Colon and Fungating Bleeding Adenocarcinoma of the Terminal Ileum Presenting Massive Rectal Bleeding: A Trap for the Unwary

Primary cancer of the ileum is rare, and when it occurs in conjunction with primary colon cancer, it becomes even more infrequent and challenging to diagnose prior to surgical intervention. Primary small bowel cancers can be overlooked and may be misidentified as small bowel mesenchymal tumours or advanced metastases from colon cancer. We present an exceedingly uncommon case of ruptured primary ileal cancer combined with primary descending colon cancer presenting with gastrointestinal bleeding. Based on our understanding, instances of dual tumours concurrently occurring are exceedingly infrequent. In this patient, there was a preoperative suspicion of bleeding from colon cancer in the descending region. However, intraoperative exploration revealed that the location of the bleeding was a terminal ileal mass. Following the surgical intervention, the patient recovered satisfactorily. Intraoperative exploration of the entire gastrointestinal tract is therefore necessary in patients with gastrointestinal haemorrhage, especially in those who require urgent surgery without adequate preoperative investigations. If a mass is detected at the end of the ileum, intraoperative pathology should be performed if feasible. Subsequently, if the diagnosis reveals an adenocarcinoma, terminal ileocolic resection and right hemicolectomy are necessary for appropriate resection.

The Role of Capsule Endoscopy in the Diagnosis and Management of Small Bowel Tumors: A Narrative Review

Small bowel tumors (SBT) are relatively rare, but have had a steadily increasing incidence in the last few decades. Small bowel capsule endoscopy (SBCE) and device-assisted enteroscopy are the main endoscopic techniques for the study of the small bowel, the latter additionally providing sampling and therapeutic options, and hence acting complementary to SBCE in the diagnostic work-up. Although a single diagnostic modality is often insufficient in the setting of SBTs, SBCE is a fundamental tool to drive further management towards a definitive diagnosis. The aim of this paper is to provide a concise narrative review of the role of SBCE in the diagnosis and management of SBTs.

Symptoms Contributing to the Diagnosis of Small Bowel Tumors

INTRODUCTION

Small bowel tumors (SBTs) are difficult to diagnose because of limited opportunities and technical difficulties in evaluating the small bowel. Asymptomatic conditions or nonspecific symptoms make SBT diagnosis more challenging. In Asia, SBTs are reported to be more frequently malignant lymphoma (ML), adenocarcinoma, and gastrointestinal stromal tumor (GIST). In this study, we examined 66 patients diagnosed with SBTs and determined their clinical characteristics.

METHODS

This retrospective study was conducted from January 2013 to July 2020 at Kurume University Hospital. The modalities used to detect SBTs were computed tomography (CT), positron emission tomography, magnetic resonance imaging, and ultrasonography. Endoscopy was also performed in some cases to confirm SBT diagnosis. The study included 66 patients. The medical data collected included presenting symptoms, tumor location, underlying condition, diagnostic modalities, pathologic diagnosis, and treatment.

RESULTS

ML and adenocarcinoma were the most common tumors (22.7%), followed by GIST (21.2%) and metastatic SBT (18.2%). Symptoms that led to SBT detection were abdominal pain (44.5%), asymptomatic conditions (28.8%), hematochezia (12.1%), and anemia (10.6%). CT was the most used modality to detect SBTs. Nineteen patients were asymptomatic, and SBTs were incidentally detected in them. GISTs and benign tumors were more often asymptomatic than other malignant tumors.

CONCLUSION

Abdominal pain was the main symptom for SBTs in particular adenocarcinoma, ML, and metastatic SBT. In addition, GIST, which was highly prevalent in Asia, had fewer symptoms. An understanding of these characteristics may be helpful in the clinical practice of SBTs.

Diagnostic Management of Gastroenteropancreatic Neuroendocrine Neoplasms: Technique Optimization and Tips and Tricks for Radiologists

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) comprise a heterogeneous group of neoplasms, which derive from cells of the diffuse neuroendocrine system that specializes in producing hormones and neuropeptides and arise in most cases sporadically and, to a lesser extent, in the context of complex genetic syndromes. Furthermore, they are primarily nonfunctioning, while, in the case of insulinomas, gastrinomas, glucagonomas, vipomas, and somatostatinomas, they produce hormones responsible for clinical syndromes. The GEP-NEN tumor grade and cell differentiation may result in different clinical behaviors and prognoses, with grade one (G1) and grade two (G2) neuroendocrine tumors showing a more favorable outcome than grade three (G3) NET and neuroendocrine carcinoma. Two critical issues should be considered in the NEN diagnostic workup: first, the need to identify the presence of the tumor, and, second, to define the primary site and evaluate regional and distant metastases. Indeed, the primary site, stage, grade, and function are prognostic factors that the radiologist should evaluate to guide prognosis and management. The correct diagnostic management of the patient includes a combination of morphological and functional evaluations. Concerning morphological evaluations, according to the consensus guidelines of the European Neuroendocrine Tumor Society (ENETS), computed tomography (CT) with a contrast medium is recommended. Contrast-enhanced magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), is usually indicated for use to evaluate the liver, pancreas, brain, and bones. Ultrasonography (US) is often helpful in the initial diagnosis of liver metastases, and contrast-enhanced ultrasound (CEUS) can solve problems in characterizing the liver, as this tool can guide the biopsy of liver lesions. In addition, intraoperative ultrasound is an effective tool during surgical procedures. Positron emission tomography (PET-CT) with FDG for nonfunctioning lesions and somatostatin analogs for functional lesions are very useful for identifying and evaluating metabolic receptors. The detection of heterogeneity in somatostatin receptor (SSTR) expression is also crucial for treatment decision making. In this narrative review, we have described the role of morphological and functional imaging tools in the assessment of GEP-NENs according to current major guidelines.

"MURAL" model to predict bleeding from mural-based lesions in potential small bowel bleeding may improve diagnostic capability and decrease cost

In potential small bowel bleeding, video capsule endoscopy (VCE) is excellent to detect mucosal lesions, while mural-based lesions are better detected by computed tomography enterography (CTE). A predictive tool to identify mural-based lesions should guide selecting investigations. In this retrospective study, we developed and validated the "MURAL" model based on logistic regression to predicts bleeding from mural-based lesions. Cost-effectiveness analysis comparing diagnostic strategy among VCE, CTE, and MURAL model was performed. Of 296 patients, 196 and 100 patients were randomly included in the derivative and validation cohorts, respectively. The MURAL model comprises 5 parameters: age, presence of atherosclerosis, chronic kidney disease, antiplatelet use, and serum albumin level. The area under the receiver operating characteristic curve was 0.778 and 0.821 for the derivative and validation cohorts, respectively. At a cutoff value of 24.2%, the model identified mural-based lesions with 70% sensitivity and 83% specificity in the validation cohort. Cost-effectiveness analysis revealed that application of the MURAL model demonstrated a comparable missed lesion rate but had a lower missed tumor rate, and lower cost compared to VCE strategy. The model for predicting mural-based lesions provide some guidance in investigative decision-making, which may improve diagnostic efficiency and reduce costs.

Small Bowel Adenocarcinoma: From Molecular Insights to Clinical Management

Small bowel adenocarcinoma (SBA) is a rare malignancy, with a rising incidence in recent decades, and accounts for roughly 40% of all cancers of the small bowel. The majority of SBAs arise in the duodenum and are associated with a dismal prognosis. Surgery remains the mainstay of treatment for localized disease, while systemic treatments parallel those used in colorectal cancer (CRC), both in the adjuvant and palliative setting. In fact, owing to the lack of prospective data supporting its optimal management, SBA has historically been treated in the same way as CRC. However, recent genetic and molecular data suggest a distinct profile from other gastrointestinal malignancies and support a more nuanced approach to its management. Herein, we briefly review the state-of-the-art in the clinical management of early-stage and advanced disease and recent discoveries of potentially actionable genetic alterations or pathways along with the most promising ongoing clinical trials, which will hopefully revolutionize the treatment landscape of this orphan disease in the foreseeable future.

Gastrointestinal neuroendocrine neoplasms (GI-NENs): hot topics in morphological, functional, and prognostic imaging

Neuroendocrine neoplasms (NENs) are heterogeneous tumours with a common phenotype descended from the diffuse endocrine system. NENs are found nearly anywhere in the body but the most frequent location is the gastrointestinal tract. Gastrointestinal neuroendocrine neoplasms (GI-NENs) are rather uncommon, representing around 2% of all gastrointestinal tumours and 20–30% of all primary neoplasms of the small bowel. GI-NENs have various clinical manifestations due to the different substances they can produce; some of these tumours appear to be associated with familial syndromes, such as multiple endocrine neoplasm and neurofibromatosis type 1. The current WHO classification (2019) divides NENs into three major categories: well-differentiated NENs, poorly differentiated NENs, and mixed neuroendocrine-non-neuroendocrine neoplasms. The diagnosis, localization, and staging of GI-NENs include morphology and functional imaging, above all contrast-enhanced computed tomography (CECT), and in the field of nuclear medicine imaging, a key role is played by ⁶⁸Ga-labelled-somatostatin analogues (⁶⁸Ga-DOTA-peptides) positron emission tomography/computed tomography (PET/TC). In this review of recent literature, we described the objectives of morphological/functional imaging and potential future possibilities of prognostic imaging in the assessment of GI-NENs.

Intraoperative Endoscopy in Transient Adult Jejunojejunal Intussusception

Despite improvements in imaging modalities, causative lead points in adult intussusception may be difficult to diagnose. Such lead points can be malignant, causing recurrence or metastases if left unresected. We describe a case of transient adult jejunojejunal intussusception, in which intraoperative endoscopy was used to confirm the absence of a lead point. A 39-year-old woman with a history of laparoscopic oophorectomy presented with epigastric pain, nausea, and vomiting. Contrast computed tomography revealed jejunojejunal intussusception, with no visible lead point. Spontaneous reduction was confirmed during exploratory laparoscopy. After lysis of adhesions, intraoperative peroral jejunoscopy was performed with the surgeons' assistance. Endoscopy confirmed the absence of tumor, and bowel resection was avoided. No recurrence has been observed during 24 months of follow-up. Intraoperative endoscopy may provide additional reassurance for the absence of a lead point in cases where preoperative enteroscopy cannot be performed and no lead points can be identified on imaging.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Challenges in Crohn's Disease Management after Gastrointestinal Cancer Diagnosis

Simple Summary

Crohn’s disease (CD) is a chronic inflammatory bowel disease affecting both young and elderly patients, involving the entire gastrointestinal tract from the mouth to anus. The chronic transmural inflammation can lead to several complications, among which gastrointestinal cancers represent one of the most life-threatening, with a higher risk of onset as compared to the general population. Moreover, diagnostic and therapeutic strategies in this subset of patients still represent a significant challenge for physicians. Thus, the aim of this review is to provide a comprehensive overview of the current evidence for an adequate diagnostic pathway and medical and surgical management of CD patients after gastrointestinal cancer onset.

Abstract

Crohn’s disease (CD) is a chronic inflammatory bowel disease with a progressive course, potentially affecting the entire gastrointestinal tract from mouth to anus. Several studies have shown an increased risk of both intestinal and extra-intestinal cancer in patients with CD, due to long-standing transmural inflammation and damage accumulation. The similarity of symptoms among CD, its related complications and the de novo onset of gastrointestinal cancer raises difficulties in the differential diagnosis. In addition, once a cancer diagnosis in CD patients is made, selecting the appropriate treatment can be particularly challenging. Indeed, both surgical and oncological treatments are not always the same as that of the general population, due to the inflammatory context of the gastrointestinal tract and the potential exacerbation of gastrointestinal symptoms of patients with CD; moreover, the overlap of the neoplastic disease could lead to adjustments in the pharmacological treatment of the underlying CD, especially with regard to immunosuppressive drugs. For these reasons, a case-by-case analysis in a multidisciplinary approach is often appropriate for the best diagnostic and therapeutic evaluation of patients with CD after gastrointestinal cancer onset.

Anatomic and Functional Imaging of Neuroendocrine Tumors

OPINION STATEMENT

Neuroendocrine tumors (NETs) can occur in a wide variety of organs and display a spectrum of pathologic behavior. Accurate and effective imaging is paramount to the diagnosis, staging, therapy, and surveillance of patients with NET. There have been continuous advancements in the imaging of NET which includes anatomic and functional techniques.

Clinical characteristics of small bowel tumors diagnosed by double-balloon endoscopy: Experience from a Chinese tertiary hospital

BACKGROUND/AIMS

To determine the characteristics of small bowel tumors (SBTs) in patients underwent double balloon endoscopy (DBE) and to compare the clinical value of DBE with other diagnostic tools.

MATERIALS AND METHODS

A retrospective study was conducted in patients underwent DBE procedures from March 2008 to April 2017.The demographic, clinical and pathological characteristics of patients with SBTs were recorded, while the diagnosis of SBTs was achieved either by DBE biopsy or surgical specimens.

RESULTS

One thousand one hundred and two patients (761 males, range 3-85 years) were enrolled in this study, with 1140 procedures completed in total. 99/1102 patients (9.0%) had SBTs, including benign polyps (20, 20.2%), gastrointestinal stromal tumors (GISTs) (24, 24.2%), lymphomas (13, 13.1%), adenocarcinoma (39, 39.4%), and neuroendocrine tumors (3, 3.0%). The most common clinical symptom for benign polyps was obscure gastrointestinal bleeding (OGIB) (75.0%). But among patients with malignant SBTs, the main indication for DBE was chronic abdominal pain (43.8%), followed by OGIB (36.3%), vomit (10.0%), abnormal images (6.3%) and diarrhea (3.8%) (P<0.001). Moreover, SBTs were primarily located in the jejunum alone (40/99, 40.4%). DBE had better sensitivity (89.2%), specificity (95.2%), positive predictive value (PPV) (90.0%), and negative predictive value (NPV) (94.8%) than other tools for suspected SBTs.

CONCLUSION

Small bowel tumor is mainly located in jejunum and with OGIB and abdominal pain as major complaints. DBE is a reliable method for the diagnosis of SBTs compared with other diagnostic tools.

Comparison of characteristic computed tomographic findings of gastrointestinal and non-gastrointestinal stromal tumors in the small intestine

PURPOSE

We aimed to reveal specific findings of gastrointestinal stromal tumors (GISTs) in the small intestine on contrast-enhanced computed tomography (CT) by comparing GISTs with non-GISTs.

METHODS

We enrolled 28 patients with 39 GISTs and 20 patients with 22 non-GISTs who underwent enterectomy with a preoperative diagnosis of small intestinal tumor. All lesions were diagnosed by histopathological examination. Two radiologists independently evaluated internal homogeneity, growth pattern, calcification, intratumoral hemorrhage, degeneration, ulceration, and lymphadenopathy and measured the maximum diameter of the tumor and contrast-enhanced CT (CECT) value of the solid portion as well as the diameter and CT value of the feeding artery and drainage vein on CECT in the arterial and venous phases.

RESULTS

Intratumoral hemorrhage was seen in 15.4% and 25.6% of GISTs and in 0% and 0% of non-GISTs (p = 0.079 and 0.010), with good interobserver agreement (κ = 0.715). The drainage vein diameter correlated well with the maximum diameter of the tumor (r = 0.744, p < 0.001). The CT value of the solid tumor part in the arterial and venous phases (p < 0.01) and the CT value of the drainage vein in the arterial phase (p < 0.05) were higher for GISTs than for non-GISTs (p < 0.01).

CONCLUSIONS

Strong parenchymal enhancement with the peak in the arterial phase and the CT value of the drainage vein in the arterial phase was characteristics findings of GIST compared with non-GISTs. The diameter of the drainage vein was proportional to the maximum diameter of GISTs.

Small bowel obstruction in a virgin abdomen

INTRODUCTION

Surgical exploration is still considered mandatory in the setting of small bowel obstruction (SBO) and a virgin abdomen by some large centers. The aim of this study is to determine the etiology of SBO in patients without prior abdominal operation.

METHODS

Retrospective review of the patients treated for SBO and virgin abdomen at the Mayo Clinic between 2006 and 2016 was performed. Follow up data, operative and pathologic findings were examined to determine the etiology of SBO.

RESULTS

Sixty patients met inclusion criteria; abdominal exploration was performed in 50 patients (83%) and 10 patients (17%) were managed non-operatively. Exploration was therapeutic in 29 (58%), negative in 20 (40%) and non-therapeutic in one patient (2%). Overall, 8 patients (13%) were diagnosed with a malignancy: right-sided colon cancer (n = 3), small bowel (SB) neuroendocrine tumor (n = 2), SB lymphoma (n = 2) and carcinomatosis peritonei (n = 1); Upon retrospective review, both SB neuroendocrine tumors and one SB lymphoma were visible on the initial imaging. Leukocytosis (p = .03) and no recent weight loss (p = .04) were associated with negative exploration.

CONCLUSION

Patients with SBO and virgin abdomen frequently have a benign etiology. Careful imaging review directed at subtle signs of an underlying malignancy is warranted. If non-operative management is chosen, close follow up is essential and it should include a careful personal and family history as well as updated colonoscopy.

Small bowel tumours: update in diagnosis and management

PURPOSE OF REVIEW

The aim of this study was to summarize the role of recently developed diagnostic techniques in the diagnosis and management of patients with small bowel tumours (SBTs).

RECENT FINDINGS

Recent studies show that the overall SBT incidence is increasing. The introduction of small bowel dedicated diagnostic tools [i.e. capsule endoscopy, device-assisted enteroscopy (DAE), computed tomography (CT) and MRI-enterography] might partially explain this trend. In patients with SBT, DAE might represent an ideal tool by coupling careful mucosal inspection with sampling capability. Unfortunately, DAE is an invasive procedure and seldom allows complete small bowel evaluation in a single setting. Therefore, DAE is more often used in clinical practice as confirmatory tool, when other less invasive and readily available tests (i.e. capsule endoscopy or radiological tests) identify relevant findings. Nevertheless, in patients with SBT, capsule endoscopy is burdened by an increased risk of capsule retention and/or missing proximal small bowel lesions, whereas dedicated cross-sectional imaging techniques often identify nonspecific findings of limited clinical significance.

SUMMARY

Despite recent technical improvements, in patients with SBT, the result of a single diagnostic procedure is often insufficient to provide a definite diagnosis. A balanced combination of different tests allows reaching a final diagnosis and drive further management.

Mass-forming lesions of the duodenum: A pictorial review

Recent advances in imaging have resulted in marked changes in the investigation of the duodenum, which still remains primarily evaluated with videoendoscopy. However, improvements in computed tomography (CT) and magnetic resonance (MR) imaging have made detection and characterization of duodenal mass-forming abnormalities easier. The goal of this pictorial review was to illustrate the most common conditions of the duodenum that present as mass-forming lesions with a specific emphasis on CT and MR imaging. MR imaging used in conjunction with duodenal distension appears as a second line imaging modality for the characterization of duodenal mass-forming lesions. CT remains the first line imaging modality for the detection and characterization of a wide range of duodenal mass-forming lesions.

A Prospective Blinded Comparison of Video Capsule Endoscopy Versus Computed Tomography Enterography in Potential Small Bowel Bleeding: Clinical Utility of Computed Tomography Enterography

GOALS

To compare the efficacy of video capsule endoscopy (VCE) with computed tomography enterography (CTE) in potential small bowel (SB) bleeding, and to identify factors predictive of a high diagnostic yield for CTE.

BACKGROUND

In potential SB bleeding, CTE potentially detects some lesions missed by VCE, but few data have determined its clinical utility.

STUDY

Consecutive patients with potential SB bleeding were prospectively enrolled. All underwent VCE and CTE within a 1-week interval. Definitive diagnoses were made by surgery or enteroscopy, except when a strategy of VCE and conservative management was suitable. The diagnostic yields and sensitivities of each investigation were measured.

RESULTS

Fifty-two patients were recruited (41 with overt and 11 with occult bleeding); 36 received a definitive diagnosis. The diagnostic yields and sensitivities of VCE and CTE were 59.6% and 30.8% (P=0.004), and 72.2% and 44.4% (P=0.052), respectively. The combined sensitivity of VCE and CTE (88.9%) was significantly greater than VCE (P=0.03) or CTE (P<0.01) alone. VCE was better for ulcers, enteritis, and angiodysplasia, whereas CTE was better for tumors and Meckel diverticula. Age below 40 years and severe bleeding were associated with a higher diagnostic yield for CTE [odds ratios (95% confidence interval)=7.3 (1.04-51.4), P=0.046 and 6.1 (1.4-25.5), P=0.014, respectively].

CONCLUSIONS

Both investigations complement each other in the diagnosis of potential SB bleeding. CTE should be considered when VCE is negative. Age below 40 years and severe bleeding were independent predictors of a higher diagnostic yield for CTE.

Detection of small-bowel tumours with CT enteroclysis using carbon dioxide and virtual enteroscopy: A preliminary study

PURPOSE

The aim of this prospective study was to evaluate the feasibility, tolerance and performance of virtual enteroscopy (VE) using carbon dioxide for small-bowel distension in patients with suspected small-bowel tumours (SBTs).

PATIENTS AND METHODS

After IRB approval, 17 patients with suspected SBTs were prospectively included. Radiation dose was compared to 34 matched patients (2 for 1) for age, gender and body weight, who had undergone CT-enteroclysis with neutral contrast (CTE). Performance of VE was evaluated through comparison with the current standard of reference, including surgery and/or enteroscopy and/or follow-up.

RESULTS

Tolerance was excellent in 16/17 patients (94%). The radiation dose was lower for VE than for CTE (533 ± 282 vs. 974 ± 505 mGy.cm; p = 0.002). With VE, a total of 25 polyps >5 mm in size were depicted in 12/17 patients. On a per-lesion analysis, sensitivity and positive predictive value of VE were 92.0% and 92.0%, respectively. On a per-segment analysis VE had a sensitivity and specificity of 95.0% and 87.0%, respectively.

CONCLUSION

Our preliminary study suggests that VE is a feasible and well-tolerated technique with high sensitivity and specificity for the diagnosis of SBT.

KEY POINTS

• Virtual enteroscopy is feasible and well tolerated. • Virtual enteroscopy appears to be accurate for detection of small-bowel tumours. • Sensitivity and PPV of virtual enteroscopy is 92.0% and 92.0%. • Radiation dose is lower with virtual enteroscopy compared to MDCT-enteroclysis.

The Surgical Management of Small Bowel Neuroendocrine Tumors: Consensus Guidelines of the North American Neuroendocrine Tumor Society

Small bowel neuroendocrine tumors (SBNETs) have been increasing in frequency over the past decades, and are now the most common type of small bowel tumor. Consequently, general surgeons and surgical oncologists are seeing more patients with SBNETs in their practices than ever before. The management of these patients is often complex, owing to their secretion of hormones, frequent presentation with advanced disease, and difficulties with making the diagnosis of SBNETs. Despite these issues, even patients with advanced disease can have long-term survival. There are a number of scenarios which commonly arise in SBNET patients where it is difficult to determine the optimal management from the published data. To address these challenges for clinicians, a consensus conference was held assembling experts in the field to review and discuss the available literature and patterns of practice pertaining to specific management issues. This paper summarizes the important elements from these studies and the recommendations of the group for these questions regarding the management of SBNET patients.

Small bowel neoplasms: enhancement patterns and differentiation using post-contrast multiphasic multidetector CT

PURPOSE

The purpose of the present study was to analyze the enhancement patterns of small bowel neoplasms on post-contrast multiphasic multidetector CT and to assess the diagnostic capacity for differentiating five tumor types.

METHODS

We performed a retrospective study of data on 92 small bowel neoplasms. The neoplasms were categorized into five groups according to pathology findings, not imaging findings (23 adenocarcinomas; 22 lymphomas; 19 metastases; 18 gastrointestinal stromal tumors [GIST]; 10 neuroendocrine tumors [NET]).

RESULTS

GIST and NET demonstrated a hypervascular pattern in the multiphasic dynamic study. Adenocarcinoma and lymphoma showed a delayed enhancement pattern. Metastasis was classified as an intermediate enhancement pattern. The receiver operating characteristic analyses revealed that attenuation thresholds could be set with acceptable accuracies for most of the small bowel neoplasms.

CONCLUSIONS

Multiphasic dynamic studies may have the potential to improve the diagnostic capacity of multidetector CT for small bowel neoplasms.

Neoplastic Diseases of the Small Bowel

The incidence of small bowel tumors is increasing over time. Until recently, their diagnosis was delayed and it was often reached only at the time of surgery. New diagnostic tools, such as capsule endoscopy, device-assisted enteroscopy, and dedicated small bowel cross-sectional imaging techniques, have been introduced recently in clinical practice. The combination of these tools allows medical practitioners to detect small bowel tumors at an early stage and to reach a definite diagnosis before surgery, thus enabling minimally invasive treatments.

Diffusion-weighted MRI in Crohn's disease: Current status and recommendations

Over the past years, technological improvements and refinements in magnetic resonance imaging (MRI) hardware have made high-quality diffusion-weighted imaging (DWI) routinely possible for the bowel. DWI is promising for the detection and characterization of lesions in Crohn's disease (CD) and has been advocated as an alternative to intravenous gadolinium-based contrast agents. Furthermore, quantification using the apparent diffusion coefficient may have value as a biomarker of CD activity and has shown promise. In this article we critically review the literature pertaining to the value of DWI in CD for detection, characterization, and quantification of disease activity and complications. Although the body of supportive evidence is growing, it is clear that well-designed, multicenter studies are required before the role of DWI in clinical practice can be fully established. J. Magn. Reson. Imaging 2016;44:1381-1396.

Diagnosis of Small-Bowel Diseases: Prospective Comparison of Multi-Detector Row CT Enterography with MR Enterography

PURPOSE

To prospectively compare the accuracies of computed tomographic (CT) enterography and magnetic resonance (MR) enterography for the detection and characterization of small-bowel diseases.

MATERIALS AND METHODS

The institutional review board approved the study protocol, and informed consent was obtained from all participants. From June 2009 to July 2013, 150 consecutive patients (81 men and 69 women; mean age, 38.8 years; range, 18-74 years), who were suspected of having a small-bowel disease on the basis of clinical findings and whose previous upper and lower gastrointestinal endoscopy findings were normal, underwent CT and MR enterography. Two independent readers reviewed CT and MR enterographic images for the presence of small-bowel diseases, for differentiating between inflammatory and noninflammatory diseases, and for extraenteric complications. The histopathologic findings of surgical (n = 23) and endoscopic (n = 32) biopsy specimens were used as the reference standard; the results of video-capsule endoscopy (n = 36) and clinical follow-up (n = 59) were used only to confirm the absence of small-bowel disease.

RESULTS

MR and CT enterography were successfully performed in all 150 patients. Overall sensitivity, specificity, and accuracy, respectively, in identifying patients with small-bowel lesions were 75.9% (41 of 54), 94.8% (91 of 96), and 88.0% (132 of 150) for CT enterography and 92.6% (50 of 54), 99.0% (95 of 96), and 96.7% (145 of 150) for MR enterography. The sensitivity of MR enterography was significantly higher than that of CT enterography for the detection of both overall small-bowel diseases (P = .0159) and neoplastic diseases (P = .0412) but not for the detection of inflammatory diseases (P > .99) or noninflammatory and nonneoplastic diseases (P = .6171).

CONCLUSION

MR enterography is more accurate than CT enterography in the detection of small-bowel diseases; MR enterography was more accurate in detecting neoplastic diseases in particular.

A jejunal GIST presenting with obscure gastrointestinal bleeding and small bowel obstruction secondary to intussusception

A 68-year-old man with episodes of overt obscure gastrointestinal (GI) bleeding was investigated with multiple upper and lower GI endoscopies, CT enterography and capsule endoscopy, but no cause was found. He then presented acutely with small bowel obstruction. A laparotomy revealed complete small bowel obstruction secondary to jejunal intussusception over a 4 cm intraluminal polyp. Following resection and primary anastomosis, histology revealed that the polyp was a GI stromal tumour (GIST). This is an exceptionally uncommon presentation of a rare tumour. It is surprising that this tumour was not detected by CT enterography and not seen on capsule endoscopy. Immunohistochemistry and mutation analysis of the GIST suggested that it had a low risk of metastatic disease, but a high risk of recurrence. Staging CT scans did not reveal evidence of distal spread. The patient is currently receiving 3 years of chemotherapy with imatinib.

Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors

Small-bowel carcinoid tumors are the most common form (42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare (3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common (20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

Beneficial effects of combining computed tomography enteroclysis/enterography with capsule endoscopy for screening tumor lesions in the small intestine

Aim. To compare the efficacy of using computed tomography enteroclysis/enterography (CTE), capsule endoscopy (CE), and CTE with CE for diagnosing tumor lesions in the small intestine. Materials and Methods. We included 98 patients who underwent CE during the observation period and were subjected to CTE at our hospital from April 2008 to May 2014. Results. CTE had a significantly higher sensitivity than CE (84.6% versus 46.2%, P = 0.039), but there were no significant differences in specificity, positive or negative predictive values, or diagnostic accuracy rates. The sensitivity of CTE/CE was 100%, again significantly higher than that of CE (P = 0.002). The difference in specificity between CTE/CE and CE was not significant, but there were significant differences in positive predictive values (100% for CTE/CE versus 66.7% for CE, P = 0.012), negative predictive values (100% versus 92.1%, P = 0.008), and diagnostic accuracy rate (100% versus 89.8%, P = 0.001). The diagnostic accuracy rate was also significantly higher in CTE/CE versus CTE (100% versus 95.9%, P = 0.043). Conclusion. Our findings suggested that a combination of CTE and CE was useful for screening tumor lesions in the small intestine. This trial is registered with number UMIN000016154.

Update on imaging of Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is a rare, autosomal dominant disease linked to a mutation of the STK 11 gene and is characterized by the development of benign hamartomatous polyps in the gastrointestinal tract in association with a hyperpigmentation on the lips and oral mucosa. Patients affected by PJS have an increased risk of developing gastrointestinal and extra-digestive cancer. Malignancy most commonly occurs in the small-bowel. Extra-intestinal malignancies are mostly breast cancer and gynecological tumors or, to a lesser extent, pancreatic cancer. These polyps are also at risk of acute gastrointestinal bleeding, intussusception and bowel obstruction. Recent guidelines recommend regular small-bowel surveillance to reduce these risks associated with PJS. Small-bowel surveillance allows for the detection of large polyps and the further referral of selected PJS patients for endoscopic enteroscopy or surgery. Video capsule endoscopy, double balloon pushed enteroscopy, multidetector computed tomography and magnetic resonance enteroclysis or enterography, all of which are relatively new techniques, have an important role in the management of patients suffering from PJS. This review illustrates the pathological, clinical and imaging features of small-bowel abnormalities as well as the role and performance of the most recent imaging modalities for the detection and follow-up of PJS patients.

Diffusion-weighted imaging for the detection of mesenteric small bowel tumours with Magnetic Resonance--enterography

PURPOSE

To retrospectively investigate the added value of diffusion-weighted MR imaging (DWI) for detecting mesenteric small bowel tumours (MSBTs) via MR-enterography.

MATERIALS AND METHODS

MR-enterographies of 98 patients with suspected MSBTs were blindly analyzed by two independent readers for the presence of MSBTs. Four imaging sets including "standard" (Haste and TrueFisp), "standard + DWI," "standard + gadolinium-enhanced" and "standard + DWI + gadolinium-enhanced" were reviewed. Diagnostic performance of different readings were compared with McNemar's test.

RESULTS

Twenty-nine MSBTs were pathologically confirmed. For R1 (junior radiologist) sensitivity, specificity, PPV, NPV and accuracy for the detection of MSBTs via standard MRI were 52 % [95 % CI: 34 %-70 %] (15/29), 94 % [95 % CI: 89 %-100 %] (65/69), 79 % [95 % CI: 61 %-97 %] (15/19), 82 % [95 % CI: 74 %-91 %] (65/79) and 82 % [95 % CI: 74 %-89 %] (80/98), respectively. For R2 (senior radiologist) they were 76 % [95 % CI: 60 %-91 %] (22/29), 96 % [95 % CI: 91-100 %] (66/69), 88 % [95 % CI: 75 %-100 %] (22/25), 90 % [95 % CI: 84 %-97 %] (66/73) and 90 % [95 % CI: 84 %-96 %] (88/98), respectively. Adding DWI they were 72 % [95 % CI: 56 %-89 %] (21/29), 91 % [95 % CI: 85 %-98 %] (63/69), 78 % [95 % CI: 62 %-94 %] (21/27), 89 % [95 % CI: 81 %-96 %] (63/71) and 87 % [95 % CI: 80 %-94 %] (85/98) for R1 and 79 % [95 % CI: 65 %-94 %] (23/29), 97 % [95 % CI: 93 %-100 %] (67/69), 92 % [95 % CI: 81 %-100 %] (23/25), 92 % [95 % CI: 86 %-98 %] (67/73) and 92 % [95 % CI: 86 %-97 %] (90/98) for R2. Sensitivities for tumour detection were higher after adding DWI to standard MRI, although only for R1 was this significant (P = 0.03). Adding DWI to standard + gadolinium-enhanced MRI did not significantly increase MR performance.

CONCLUSION

DWI improves MSBT detection via MR-enterography compared to standard unenhanced MR-enterography, especially for unexperienced readers.

KEY POINTS

• MR-enterography is accurate for the detection of mesenteric small-bowel tumours. • Diffusion-weighted sequencing helps inexperienced readers detect small-bowel tumours with MR-enterography. • Diffusion-weighted sequencing adds value to standard MR-enterography when gadolinium is contraindicated.

Prospective evaluation of magnetic resonance enterography for the detection of mesenteric small bowel tumours

PURPOSE

To prospectively evaluate magnetic resonance (MR) enterography for detecting mesenteric small-bowel tumours (MSBTs) and assess the added value of gadolinium-chelate injection.

MATERIAL AND METHODS

Over a 2-year period MR enterography examinations of 75 patients (33 men, 42 women; mean age, 53.8 years; range, 19-85) with suspected MSBT were blindly analysed by two readers for the presence of MSBT. Sensitivities, specificities, predictive positive values (PPVs), negative predictive values (NPVs) and accuracies of MR enterography for the detection of MSBT were calculated on per-patient and per-lesion bases. The McNemar test was used to compare sensitivities and specificities of the unenhanced and gadolinium-enhanced sets of MR enterographies.

RESULTS

Thirty-seven MSBTs were pathologically confirmed in 26 patients. The mean tolerance score of the examinations was 0.7. On a per-patient basis, sensitivity, specificity, PPV, NPV and accuracy for detection of MSBT were 96 % [95 % CI, 89-100 %], 96 % [90-100 %], 93 % [83-100 %], 98 % [94-100 %] and 96 % [92-100 %], respectively. On a per-lesion basis, sensitivity and PPV were 70 % [56-85 %] and 93 % [83-100 %], respectively. Gadolinium injection yielded higher sensitivities on both bases (P = 0.008).

CONCLUSION

MR enterography is an accurate and well-tolerated imaging modality for detecting MSBT. Intravenous administration of gadolinium-chelate improves sensitivity for MSBT detection.

KEY POINTS

• MR enterography accurately detects mesenteric small bowel tumours. • MR enterography is a well-tolerated imaging technique. • Intravenous administration of gadolinium chelate improves sensitivity for detecting small-bowel tumours.

Carcinoid tumors of the small-bowel: evaluation with 64-section CT-enteroclysis

PURPOSE

To describe the imaging presentation of carcinoid tumors of the small-bowel at 64-section CT-enteroclysis and determine the sensitivity of this technique for tumor detection.

PATIENTS AND METHODS

The 64-section CT-enteroclysis examinations of 22 patients with histopathologically proven small-bowel carcinoid tumors and those of 6 patients with suspected recurrence after small-bowel resection for carcinoid tumor were reviewed. Images were analyzed with respect to imaging presentation. Sensitivity, specificity, and accuracy, of 64-section CT-enteroclysis for the diagnosis of carcinoid tumor of the small-bowel were estimated with 95% confidence intervals (CIs).

RESULTS

Twenty-five carcinoid tumors were confirmed in 22 patients (prevalence, 22/28; 79%). Overall sensitivity for carcinoid tumor detection was 76% (19/25; 95%CI: 55-91%) on a per-lesion basis. On a per-patient basis, 64-section CT-enteroclysis had a sensitivity of 86% (19/22; 95%CI: 65-97%), a specificity of 100% (6/6; 95%CI: 54-100%) and an accuracy of 89% (25/28; 95%CI: 72-98%) for the diagnosis of carcinoid tumor. Focal small-bowel wall thickening, mesenteric stranding, and mesenteric mass were found in 20/22 (91%), 18/22 (82%) and 15/22 (68%) patients with pathologically confirmed tumors.

CONCLUSION

64-Section CT-enteroclysis shows highly suggestive features for the diagnosis of carcinoid tumor of the small-bowel and achieves high degrees of sensitivity for tumor detection.