Magnetic resonance imaging for assessment of rectal cancer nodes after chemoradiotherapy: A single center experience.

BACKGROUND: Accurate nodal restaging is becoming clinically more important in patients with locally advanced rectal cancer (LARC) with the emergence of organ-preserving treatment after a good response to neoadjuvant chemoradiotherapy (nCRT). PURPOSE: To evaluate the accuracy of MRI in identifying negative N status (ypN0 patients) in LARC after nCRT. MATERIAL AND METHODS: 191 patients with LARC underwent MRI before and 6-8 weeks after nCRT and subsequent total mesorectal excision. Short-axis diameter of mesorectal lymph nodes was evaluated on the high resolution T2-weighted images to compare MRI restaging with histopathology.. RESULTS: 146 and 45 patients had a negative N status (ypN0) and positive N status (ypN + ), respectively. On restaging MRI, the 70 % reduction in size of the largest node was associated with an area under the curve (AUC) of 0.818 to predict ypN0 stage, with a sensitivity of 93.3 % and a negative predictive value (NPV) of 95.4 %. No nodes were observed in 38 pts (37 pts ypN0 and 1 patient ypN + ), with sensitivity and NPV of nodes disappearance for ypN0 stage of 93.3 % and 92.5 % respectively. A 2.2 mm cut-off in short-axis diameter was associated with an AUC of 0.83 for the prediction of ypN0 nodal stage, with sensitivity and NPV of 79,5% and 91.1 % respectively. CONCLUSION: A reduction in size of 70 % of the largest limph-node on MRI at rectal cancer restaging has high sensitivity and NPV for prediction of ypN0 stage after nCRT. The high NPV of node disappearance and of a ≤ 2.2 mm short-axis diameter is confirmed.

Imaging of Strictures in Crohn's Disease.

Crohn's disease (CD) is a chronic inflammation of the digestive tract, and it frequently affects young patients. It can involve any intestinal segment, even though it frequently affects the distal ileum. Up to 80% of patients with CD present with inflammatory behavior, and 5% to 28% develop stricturing disease. Based on the predominant mechanism causing them, strictures can be categorized as inflammatory, fibrotic, or mixed. Determining the relative amounts of inflammation and fibrosis in a stricture can influence treatment decisions. Imaging is an extremely useful tool in patients with small bowel stricturing CD to confirm the diagnosis and to evaluate disease characteristics, usually using CT or MRI. The aim of this paper is to describe how imaging can evaluate a patient with small bowel CD stricture.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography, Part II: The Reliable Disclosure of Crohn's Disease and Non-Inflammatory Small Bowel Disorder Plot through MRI Findings.

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but a rigorous methodology for describing and interpreting the pathological findings is mandatory. Strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, strictures, and mesentery fat hypertrophy are all indicators of small bowel damage in inflammatory and non-inflammatory small bowel disease, and they are all commonly and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. Differential MRE appearance allows us to distinguish between Crohn's disease and non-inflammatory small bowel disorder. The purpose of this paper is to present the MRE pathological findings of small bowel disorder.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography: Part I: Guidance in Performing and Observing Normal and Abnormal Imaging Findings.

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but the indications, interpretation of imaging findings, methodology, and appropriate use must be standardized and widely known. Several signs of small bowel damage in inflammatory and non-inflammatory small bowel pathology include strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, and mesentery fat hypertrophy, all of which are widely and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. The differential MRE appearance allows us to distinguish between different small bowel pathologies, such as neoplastic and non-neoplastic small bowel diseases. The purpose of this paper is to present the MRE technique, as well as the interpretation of imaging findings, through the approach of a rigorous stepwise methodology.

How the Radiologist Must Reason for a Correct Diagnosis in Patients With Small Bowel Mural Thickening Studied by CT or MRI: A Pictorial Review.

Conditions that lead to small bowel mural thickening fall into a broad spectrum of diseases, including inflammatory, infectious, vascular or neoplastic. Computed tomography (CT) and Magnetic Resonance Imaging (MRI), especially CT-enterography and MR-enterography, permit evaluation of both entire small bowel and extraluminal structures. In CT/MR-enterography, the main prerequisite for the correct evaluation of small bowel is to obtain optimal intestinal distension. In fact, most errors are related to poor intestinal distension of the bowel which can lead to interpret as pathological a small bowel segment that is not very distended (false positive), or not to recognize presence of pathology in a collapsed segment (false negative). Once the examination has been performed, the images are analyzed in order to identify the presence of small bowel pathology. Pathology of the small bowel can manifest as endoluminal alteration and/or intestinal wall thickening. Once bowel wall thickening has been identified, the radiologist's first objective is trying to define benign or malignant nature of the alteration, using also patient's history and clinical features. Once the suspicion of benign or malignant pathology has been raised, the radiologist must try to formulate a diagnosis of nature. In this pictorial review we describe how the radiologist must reason for a correct diagnosis by answering a pattern of sequential questions in a patient with suspected small bowel disease studied by CT or MRI.

Length of the healthy and pathological small intestine in patients with Crohn's disease: calculations using computed tomography and magnetic resonance enterography.

Many patients with Crohn's disease (CD) require surgical intervention during their lifetime. A correct preoperative assessment of the intestinal length is necessary to predict and quickly treat postoperative nutritional disorders. The aim of this paper is to explain the method used in our hospital to measure intestinal length in patients with CD and its usefulness for making the correct therapeutic decision. Vessel analysis software is used to measure small bowel length through computed tomography enterography (CTE) or magnetic resonance enterography (MRE). The method permits two-dimensional and three-dimensional curved multiplanar reconstructions and allows each loop to be stretched using a point-by-point identification of the intestinal lumen. Subsequently, the software allows the creation of a virtual image, on which the intestinal length is measured linearly. This methodology was tested on three patients; patients 1 and 3 were examined using CTE, and patient 2 was examined using MRE. The outcomes were discussed at a multidisciplinary team meeting (MDT). As a result, surgical ileocolic resection was recommended for patient 1 and medical therapy for patients 2 and 3. Intestinal length measurements have proved vital during MDTs for making appropriate therapeutic decisions.

Radiomics could predict surgery at 10 years in Crohn's disease.

BACKGROUND: Predicting clinical outcomes represents a major challenge in Crohn's disease (CD). Radiomics provides a method to extract quantitative features from medical images and may successfully predict clinical course. AIMS: The aim of this pilot study is to evaluate the use of radiomics to predict 10-year surgery for CD patients. METHODS: We selected a cohort of CD patients with CT scan enterographies and a 10-year follow up. The R library Moddicom was used to extract radiomic features from each lesion of CD, segmented in the CT scans. A logistic regression model based on selected radiomic features was developed to predict 10-year surgery. The model was evaluated by computing the area under the curve (AUC) of the receiver operating characteristic curve, sensitivity, specificity, positive and negative predictive values (PPV, NPV). RESULTS: We enroled 30 patients, with 44 CT scans and 93 lesions. We extracted 217 radiomic features from each lesion. The developed model was based on two radiomic features and presented an AUC (95% CI) of 0.83 (0.73-0.91) in predicting 10-year surgery. Sensitivity, specificity, PPV, NPV of the radiomic model were equal to 0.72, 0.90, 0.79, 0.86, respectively. CONCLUSION: Radiomics could be a helpful tool to identify patients with high risk for surgery and needing a stricter monitoring.

CT and MRI Evaluations in Crohn's Complications: A Guide for the Radiologist.

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory intestinal conditions with unknown etiology. Crohn's disease (CD) and ulcerative colitis (UC) are the two main types of IBD and they have some interchangeable and some different clinical and pathological characteristics. When diagnosis is performed for the first time, the majority of CD patients have a predominant inflammatory condition. As the disease progresses most patients experience the development of complications, such as abscesses, fistulas, perforation, strictures, and others. Both computed tomography (CT) and Magnetic Resonance Imaging (MRI) allow great view of the whole length of the intestinal tract together with the eventual extra-and intra-intestinal complications. MR enterography (MRE) and CT enterography (CTE), performed after oral administrations of contrast medium, have similar diagnostic accuracy for the diagnosis of CD and its complications. Even though CT is still the most familiar diagnostic technique used for studying CD worldwide, MRE have several important benefits that are leading to rapid increase in its employment in the last years. In particular, MRE allows a superior soft tissue contrast resolution compared to CT, offering a better visualization of bowel wall and its inflammatory and fibrotic characteristics. Moreover, Pelvic Magnetic Resonance is the principal technique in patients with perianal disease due to its ability of providing precise and fine detail images of the sphincter complex, which are crucial for evaluating pelvic disease. In this paper we describe common and uncommon complications in patients with CD, and explain how to identify their findings in CT and MR exams.

Usefulness of 18FDG-PET/CT and MRI in an immunocompetent patient with fever of unknown origin and following diagnosis of skeletal tuberculosis: A case report.

INTRODUCTION: Fever of unknown origin (FUO) is one of the most difficult diagnostic dilemmas in current medicine. The main causes of FUO in developed countries are non-infectious inflammatory diseases, while infections are predominant in developing countries. Among infections, Mycobacterium Tuberculosis (TB) is the most frequent cause and it can involve multiple tissues and organs. CASE AND OUTCOMES: We report a case of FUO in an immunocompetent patient with fever of unknown origin, finally diagnosed with skeletal TB thanks to a multidisciplinary approach, using FDG-PET/CT, MRI, and biopsy. PET/CT findings were non-specific (infection or inflammation versus malignancy); therefore, hip Magnetic Resonance Imaging (MRI) was performed and infection was suspected on basis of MRI findings, so a bone biopsy was then performed and skeletal TB was diagnosed. DISCUSSION: A successful diagnostic workup of FUO has to take into account detailed medical history, physical examination, laboratory tests, blood and urine cultures, and standard imaging (Ultrasonography, CT, or MRI). However, this combination of clinical evaluation, standardized laboratory tests and simple imaging procedures often do not lead to a definite diagnosis; 8F-FDG-PET-CT could be performed to help in diagnosis and also to guide additional diagnostic tests such as MRI and biopsy. CONCLUSION: This case demonstrates the importance of the integration of different imaging modalities, in particular, MRI and FDG-PET/CT in patients with FUO. Skeletal TB should always be included in the diagnostic hypothesis of FUO, even in immunocompetent patients of non-endemic countries.

Challenges in Crohn's Disease Management after Gastrointestinal Cancer Diagnosis.

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.

A review of Magnetic Resonance Enterography classification and quantitative evaluation of active disease in patients with Crohn's disease.

Crohn's disease (CD) is a chronic inflammation of the gastro-intestinal system in which episodes of clinical worsening alternate with episodes of clinical regression. Monitoring of disease is mandatory to evaluate the efficacy of therapy and it is usually performed using a combination of clinical symptoms, laboratory tests, endoscopy and radiological exams, such as MR enterography or CT enterography. MR enterography should be preferred to CT enterography because of the absence of ionizing radiation, a very high soft tissue contrast, and a lower incidence of adverse events. In 2003, Maglinte introduced a radiological classification to identify patients in different stages of disease (active inflammatory, fibrostenotic and fistulising/perforating subtypes), based on following parameters: oedema, ulcers, stenosis, mural thickening, stratified contrast enhancement, engorged vasa recta, fistulae/abscess and mesenteric inflammation. In general, medical therapy is efficient in reducing inflammation while fibrotic disease and fistulising subtypes usually require surgery. Moreover, in patients with active CD it is important to quantify disease activity in order to adequately plan therapy and to monitor drug effects, by using some MR enterography indexes such as MaRIA score, Clermont index, and others. In this review we describe how to apply Maglinte's classification in MR enterography exams and how to quantify active disease.

CT of the acute colonic diverticulitis: a pictorial essay.

Acute colonic diverticulitis (ACD) is an acute episode of severe and prolonged lower abdominal pain due to diverticular inflammation, usually associated with change in bowel movements, fever, and leukocytosis. Worldwide, computed tomography (CT) of the abdomen and pelvis with intravenous contrast is accepted as the best imaging method for evaluating the diverticular inflammation, serving the following functions: confirming the presence of ACD; evaluation of the disease severity and degree; therapy planning guide in presence of complications (such as abscess or intestinal perforation); diagnosis of other diseases that may simulate diverticular inflammation. In the literature, we found values of CT sensitivity for diverticular inflammation from 79% to 99%; CT is useful in differentiating other diseases, which may cause abdominal pain, when diverticular inflammation is not the cause, such as neoplasm, inflammatory bowel disease, appendix inflammations, epiploic appendix inflammation and colon ischemia. The trick to differentiate diverticulitis from other inflammatory diseases that involve the colon is the identification of diverticula in the pathological intestinal loop. In the last years, a radiological classification was created in order to guide the management of ACD in patients treated conservatively or with interventional procedures. The new classification system divides ACD into two groups: complicated and uncomplicated. Uncomplicated ACD is defined if only thickening of the intestinal wall is present, with increase of the perivisceral fat density. Complicated ACD is divided into 4 stages, depending on presence of microperforation without abscess and/or peritoneum involvement (stage 1 A), presence of abscess with diameter ≤4 cm (stage 1 B), presence of abscess with diameter >4 cm (stage 2 A), presence of distant air >5 cm from the pathological loop (stage 2 B), presence of diffuse fluid in at least two distant abdominal quadrants without distant free air (stage 3), presence of diffuse fluid and distant free air (stage 4). In this pictorial essay, we describe CT findings of the ACD and explain classification of the disease and its common and uncommon complications.

A modern multidisciplinary approach to the treatment of enterocutaneous fistulas in Crohn's disease patients.

INTRODUCTION: Enterocutaneous fistulas (ECFs) is a manifestation of penetrating Crohn's disease (CD) that is challenging to treat and has considerable morbidity and mortality rates. AREAS COVERED: This review aims to explore the practical and updated principles for the optimal treatment of ECFs in CD patients. EXPERT OPINION: Optimal ECF management requires a multidisciplinary approach. Treatment first includes fluid resuscitation and electrolyte rebalancing with control of sepsis by means of antibiotics and, when indicated, drainage of infected collections. Subsequent therapeutic steps include nutritional support, control of the fistula output and treatment of peristomal skin. Anti-TNF-α therapy seems to have limited utility only after sepsis is resolved and intestinal stenosis excluded. However, ECFs heal in only approximately one-third of cases without surgical intervention. Thus, correct surgical timing combined with adequate nutritional support, sepsis resolution and skin care is considered the appropriate preoperative setting.

Crohn's disease activity before and after medical therapy evaluated by MaRIA score and others parameters in MR Enterography.

AIM: Aim of this retrospective study is to evaluate the response to therapy in Crohn's disease (CD) patients studied by MR Enterography (MRE) in comparison with Harvey Bradshaw Index (HBI). METHODS: One hundred and sixty patients with histological proved CD have undergone MRE in the last years. Forty-six patients who repeated MRE after medical therapy within six months were selected for the study. Magnetic Resonance Index of Activity (MaRIA) was evaluated for each patient and used to define the MR judgment. In MRE we also evaluated wall thickening, longitudinal extension of wall thickening, presence of stratified mural hyperenhancement and extraintestinal signs. The clinical response to therapy was judged based on HBI and classified as improved, worsened or stable disease. Clinical judgment was correlated with MRE findings and the agreement was analysed using the Cohen Kappa test. RESULTS: Among 46 enrolled patients, 18 (39%) improved clinically, 4 (10%) worsened, 24 (51%) remained stable. MR judgment was in agreement with clinical assessment in 33 patients (72%), showing moderate significant concordance (Kappa = 0.49; p < 0.01). No agreement was observed in 13 (28%) patients. Moreover, clinical improvement was significantly correlated to reduction of wall thickening, reduction of longitudinal extension of the disease and reduction of engorged vasa recta (p < 0.05). Worsening conditions were significantly correlated to increased wall thickening (p = 0.05). CONCLUSIONS: MRE is useful in evaluating the response to therapy in CD patients.

A Case of Primary Localized Small Bowel Amyloidosis Studied by 18F-Choline and Contrast-Enhanced 18F-FDG PET/CT.

Amyloidosis is a rare hereditary or acquired protein deposition disorder with different etiologies, characterized by pathological protein deposition essentially in nearly any organs or tissues. There are 2 major forms: primary and secondary amyloidosis. Moreover, it is possible to have systemic or localized disease. The localized form of amyloidosis affecting the small intestine is rare, and it is characterized by the formation of precursor proteins at the site of the lesion. We report a case of localized small bowel amyloidosis studied by F-choline and F-FDG-iodinated PET/CT performed for staging an aggressive prostatic cancer.

Muscle Recurrence of a Primarily Nodal Follicular Lymphoma Studied by Contrast-Enhanced 18F-FDG PET/CT.

We report the case of a 52-year-old woman with follicular lymphoma localized in the left inguinal region without any extranodal involvement and achieving a complete response after radiotherapy. After a 3-year disease-free interval, muscular recurrence at the left arm was shown by contrast-enhanced F-FDG PET/CT. Contrast-enhanced F-FDG PET/CT performed after immunochemotherapy documented complete disease remission. Lymphoid tissue is usually not present in the skeletal muscle, making muscular lymphomatous involvement quite unusual; muscular relapse of a primarily nodal lymphoma is even rarer.

Assessment of Crohn's Disease Activity: Magnetic Resonance Enterography in Comparison with Clinical and Endoscopic Evaluations.

Crohn's disease (CD) is a chronic inflammatory condition characterized by continuous mucosal damage and ongoing wound healing of the intestines. The fibrinolytic system is involved in early parts of the wound healing process. Fibrin is a key mediator of primary blood clot formation and is formed by cross-linking of fibrinogen. To gain insights into the dynamics of wound healing in CD patients we investigated the conversion of fibrinogen into fibrin by the pro-peptide FPA, the amount of factor XIII cross-linked fibrin and total fibrin clot. METHODS: Serum samples of 35 CD patients, 15 non-inflammatory bowel disease (non-IBD) patients and 39 age-matched healthy controls were analyzed for three novel neo-epitope markers: D-fragment and D-dimer, reflecting the degradation of total fibrin clot and factor XIII cross-linked fibrin, as well as FPA, reflecting synthesis of fibrin. RESULTS: Crohn's disease patients had a significantly lower D-dimer level (p=0.0001) compared to healthy controls. Crohn's disease and non-IBD patients had a significantly higher level of FPA (p<0.0001) and D-fragment/D-dimer ratio (p<0.0001 and p=0.02). FPA, D-dimer and D-fragment/D-dimer ratio could distinguish CD patients from healthy controls with area under the curve of 0.92 (95% CI 0.83-0.97), 0.78 (95% CI 0.67-0.87) and 0.85 (95% CI 0.75-0.93), respectively. CONCLUSION: Wound healing parameters were clearly changed in CD patients. FPA levels were higher in CD patients as compared to healthy controls, indicating more ongoing wound healing. D-dimer levels were lower in CD patients than in healthy controls, indicating impaired wound healing due to poor quality of factor XIII cross-linked fibrin and clot resolution.

Richter Syndrome Presenting With Colon Localization.

A 75-year-old man, who had been diagnosed with small lymphocytic lymphoma with cervical localization, underwent F-FDG PET/CT with iodinated contrast medium due to the appearance of cervical swelling suspected of illness relapse. PET/CT revealed intense F-FDG uptake in multiple cervical and subdiaphragmatic lymph nodes and in the left parotid. Moreover, diffuse uptake and wall thickening of the colon were evident; endoscopy with biopsy revealed a diffuse large B-cell lymphoma. Transformation into a more aggressive lymphoma occurs in 2% to 8% of small lymphocytic lymphoma, the so-called Richter syndrome. Extranodal localization in the sigmoid colon is an extremely rare site for transformed lymphoma.

Multiparametric Evaluation Predicts Different Mid-Term Outcomes in Crohn's Disease.

AIM: To evaluate if a single and/or combined (clinical, endoscopic and radiological) assessment could predict clinical outcomes in Crohn's disease (CD). METHODS: We prospectively evaluated 57 CD cases who underwent both a colonoscopy and a CT-enterography (CTE). Harvey-Bradshaw Index (HBi), SES-CD (and/or Rutgeerts score) and the radiological disease activity were defined to stratify patients according to clinical, endoscopic and radiological disease activity respectively. Hospitalizations, surgery, therapeutic changes and deaths were evaluated up to 36 months (time 1) for 53 patients. RESULTS: CTE and endoscopy agreed in stratifying disease activity in 47% of cases (k = -0.05; p = 0.694), CTE and HBi in 35% (k = 0.09; p = 0.08), endoscopy and HBi in 39% (k = 0.13; p = 0.03). Taken together, CTE, endoscopy and HBi agreed only in 18% of cases (k = 0.01; p = 0.41). Among the 11 cases with mucosal healing, only 3 (27%) showed transmural healing. Patients with endoscopic activity needed significantly more changes of therapy compared to patients with endoscopic remission (p = 0.02). Patients with higher transmural or clinical activity at baseline required significantly more hospitalizations (p < 0.01). Hospitalization rate decreases with an increase in the number of parameters indicating remissions at baseline (p = 0.04). CONCLUSIONS: Clinical, endoscopic and radiological assessments offer complementary information and could predict different mid-term outcomes in CD.

Enterography CT without and with water enema in patients with Crohn's disease: Results from a comparative observational study in comparison with endoscopy.

OBJECTIVES: CT is nowadays an examination routinely performed in Crohn's disease (CD) patients. However, there are several ways to assess gastro-intestinal tract, in particular colonic segments. Aim of this study is to compare enterography-CT (E-CT), performed after oral administration of polyethylene-glycol solution (PEG-CT) versus enterography-CT performed also with water enema via rectum (ECT-WE) in patients with CD. METHODS: We have studied 79 patients with CD undergone to enterography-CT (42 evaluated with PEG-CT and 37 with ECT-WE) who have performed a lower endoscopy within 15 days before CT. CT results concerning large bowel were compared with endoscopic findings. Intestinal distension, discomfort of the patients, sensitivity, specificity and diagnostic accuracy were evaluated. Pearson test was used for statistical analysis. RESULTS: Degree of abdominal pain was significantly higher in patients underwent to ECT-WE compared to PEG-CT. Distension of the colon was significantly greater in patients studied with ECT-WE compared to those studied with PEG-CT. Values of sensitivity, specificity and diagnostic accuracy of PEG-CT and ECT-WE were respectively 77, 86.5 and 81%, and 89, 100 and 92% in comparison with endoscopy. CONCLUSIONS: In patients with CD, ECT-WE allows the evaluation of large bowel in addition to small bowel better than PEG-CT.