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Purpose To assess image quality, interpretability, diagnostic accuracy, and radiation exposure of a computed tomography (CT) scanner with 16-cm coverage and 230-µm spatial resolution at coronary artery evaluation in patients with atrial fibrillation (AF) by using invasive coronary angiography (ICA) as the reference method and to compare the results with those obtained in patients with sinus rhythm (SR). Materials and Methods Written informed consent and institutional ethics committee approval were obtained. Between March 2015 and February 2016, 166 consecutive patients were prospectively enrolled (83 with AF, 83 with SR). They underwent ICA and coronary CT angiography performed with a whole-heart CT scanner. Image quality, coronary segment interpretability, effective dose (ED), and diagnostic accuracy were assessed at CT angiography and were compared with those attained with ICA. Diagnostic performance of the groups was compared with the pairwise McNemar test. Results Mean heart rate during scanning was 83 beats per minute ± 21 (standard deviation) in the AF group and 63 beats per minute ± 14 in the SR group (P < .01). Coronary interpretability was 98.5% in the AF group and 98.4% in the SR group (P = .96). In a segment-based analysis, sensitivity and specificity in the detection of coronary stenosis of more than 50% compared with detection of ICA were 96.4% and 98.7%, respectively, in the chronic AF group (P = .98) and 95.6% and 98.1%, respectively, in the SR group (P = .32). In a patient-based analysis, sensitivity and specificity were 95.2% and 97.6%, respectively, in the chronic AF group (P = .95) and 97.8% and 94.7%, respectively, in the SR group (P = .93). Conclusion Whole-heart CT enables evaluation of coronary arteries with high image quality, low radiation exposure, and high diagnostic accuracy in patients with chronic AF, with a diagnostic performance similar to that in patients with SR. © RSNA, 2017 Online supplemental material is available for this article.

Introduction: Peripheral neuroblastic tumors (PNTs) account for 8%–10% of all pediatric tumors. Adrenal glands and sympathetic ganglia are the commonest site of tumor growth. In the clinicopathologic spectrum of PNTs, neuroblastoma and ganglioneuroma are the most primitive and the most mature tumor form, while ganglioneuroblastoma represents an intermediate state of maturation. Surgical resection is the therapy of choice in localized disease, but can lead to serious complications when performed in the presence of certain imaging-defined risk factors. Case presentation: We present a rare case of primary intrarenal ganglioneuroblastoma diagnosed in a teenager who underwent conservative surgery and, despite this, developed upper pole renal ischemia without loss of parenchymal function. Conclusion: We underline the complex management of these extremely rare cases of neuroblastic tumors, which require a dedicated multidisciplinary team.

Contrast-enhanced computed tomography colonography (CE-CTC) is a useful guide for the laparoscopic surgeon to avoid incorrectly removing the colonic segment and the failure to diagnose of synchronous colonic and extra-colonic lesions. Lymph node dissection and vessel ligation under a laparoscopic approach can be time-consuming and can damage vessels and organs. Moreover, mesenteric vessels have extreme variations in terms of their courses and numbers. We describe the benefit of using an abdominal vascular map created by CE-CTC in laparoscopic colorectal surgery candidates. We describe patients with different diseases (colorectal cancer, diverticular disease, and inflammatory bowel disease) who underwent CE-CTC just prior to laparoscopic surgery.

Rationale and objectives: A new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography. Materials and Methods: Fifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%–80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P

Optical colonoscopy represents the diagnostic and therapeutic gold standard for most colonic pathologies, including screening for colorectal cancer and removal of polyps. Although in the last years alternative techniques have been developed in order to improve patient tolerance to colonoscopy, it remains associated with potential pain and discomfort and still has a risk for morbidity and mortality. Following diagnostic or therapeutic colonoscopy, imaging may be requested to investigate suspected iatrogenic complications, particularly perforation and haemorrhage. After endoscopy, radiographic and CT imaging generally show gaseous distension, absence of faeces and possible air–fluid levels of the large bowel. Metallic clips may be observed after endoscopically control of post-polypectomy bleeding. The post-polypectomy electrocoagulation syndrome (PPES) is characterised by focal colonic wall thickening and adjacent peritoneal inflammation in absence of perforation, demonstrated by CT imaging after polypectomy with electrocautery. Clinically, PPES closely mimics signs and symptoms of colonic perforation, but is a self-limiting condition which is amenable to a conservative therapy. Radiologists’ awareness of this entity and CT differentiation from perforation are crucial to obviate unnecessary invasive treatments. A typical case of PPES is presented.

Optical colonoscopy carries a low but real risk for morbidity and mortality, which increases as endoscopy assumes a more therapeutic role. Adverse event rate is about 0.3 % and almost 85 % of serious complications occur in patients undergoing polypectomy. Perforation and haemorrhage, the commonest specific complications, may be unrecognised during the procedure. Furthermore, clinical symptoms and laboratory signs often develop late; therefore, prompt adequate imaging is mandatory in case of clinical suspicion. Plain radiographs have limited sensitivity in detection of pneumoperitoneum and extraperitoneal gas. Multidetector computed tomography (CT) represents the best technique to assess free air or fluid, colonic injuries and bleeding.

Congenital abnormalities of coronary arteries are an uncommon cause of sudden cardiac death and are difficult to detect at coronary angiography. We describe two patients with acute coronary syndrome and non-occlusive coronary artery disease in which a 64-multidetector computed tomography (MDCT) coronary angiography showed the presence of a malignant coronary anomaly. Sixty-four-MDCT with the possibility of 3D reconstructions allows for easier diagnosis of coronary anomalies and provides essential details necessary for operative intervention.

Pelvic osteomyelitis is a very uncommon complication of Crohn's disease, usually clinically unsuspected in the setting of acute Crohn's disease relapses. The case of a 21-year old patient is reported, in whom ileo-cecal inflammatory disease was complicated by fistulization to the presacral space and sacral osteomyelitis, plus multiple abscesses involving the iliopsoas, posterior paravertebral and gluteal muscles. As confirmed by surgical and pathological findings, MRI provided comprehensive imaging diagnosis by demonstrating both the pathogenesis and the full extent of the complex, deep pelvic inflammatory process. Low back pain in patients with Crohn's disease should not be underestimated since its differential diagnosis includes serious and potentially life-threatening causes such as osteomyelitis, so prompt assessment with cross sectional imaging, particularly MRI, is necessary.

Although relatively uncommon, many different infectious, hemorrhagic and neoplastic disease processes may involve the iliac and psoas muscles and are increasingly diagnosed especially in referral hospitals. Furthermore, the iliopsoas compartment may become injured during trauma, percutaneous instrumentation, laparoscopic or open surgical procedures. State-of-the-art cross-sectional imaging including volumetric multidetector CT and multiplanar MRI acquisitions allows prompt detection, comprehensive visualization and confident characterization of most iliopsoas lesions, and the possibility to guide percutaneous biopsy and drainage. The pertinent regional anatomy is reviewed in correlation with disease pathways and imaging modalities. Neoplastic lesions, purulent and mycobacterial iliopsoas infections are discussed with examples. Imaging plays the key role in the differentiation of primary versus secondary abscesses due to intestinal, urinary and musculoskeletal infections, that determines medical therapy and surgical need. The iliopsoas compartment may become involved through direct extension by retroperitoneal, skeletal and pelvic tumors, and should be carefully scrutinized when reviewing oncologic imaging studies since it represents one of the preferred sites of skeletal muscle metastatization. Iliopsoas hemorrhages due to trauma, aortic aneurysms and anticoagulation are reviewed, with a special focus on determining whether the bleeding comes from aneurysmal rupture or from coagulopathy, a critical differentiation to decide about medical or surgical treatment. Postoperative complications involving the iliopsoas compartment are discussed with examples, including retroperitoneal bleeding, infections, urinary leaks and collections following various surgical or instrumentation procedures. Emphasis is placed on choosing the correct imaging modality and technique, particularly to detect active bleeding or urine leakage, and to reduce artifacts related to presence of metallic implants.

Extraintestinal manifestations (EIMs) occur in up to 30 % of patients affected by IBD. Hepato-bilio-pancreatic (HBP) complications are one of the most common EIM and primary sclerosing cholangitis (PSC) is by far the most important condition associated. ERCP has been considered for years the gold standard for the diagnosis of PSC. Imaging demonstration of diffuse, multifocal strictures and irregularities involving the medium-sized intrahepatic and/or medium or large-sized extrahepatic ducts is the gold standard for this diagnosis. Nowadays MRCP represents a valid alternative to ERCP depicting bile ducts in their natural degree of distension, using as contrast medium the bile itself. As a consequence, strictures, biliary sludge and stones, which normally may limit studies with contrast medium, do not limit the evaluation of bile ducts with MRCP. Furthermore, MRCP is a less expensive technique, avoiding ionizing radiation and anaesthesia. Other less common HPBs are: autoimmune pancreatitis, IgG4 associated cholangitis, small ducts PSC and CCA. CCA is a fearful and relatively common complication of PSC and the distinction between a benign dominant stricture and CCA in a PSC patient is challenging. Cholangiographic features that suggest CCA include irregular high grade ductal narrowing, rapid progression of the strictures, marked ductal dilatation proximal to strictures, and presence of polypoid lesions.

Focused MRI of the anus and perianal region should be performed on high- magnetic-field scanners operating at 1–1.5 T. Acquisition using 1.5-T clinical equipment is recommended but (as our experience confirms) a 1.0-T scanner is adequate, although it does pose disadvantages in terms of the duration of the exam [1].

Involvement of the urinary tract and genital organs is not uncommon in patients affected with Crohn’s disease (CD). Occurring in both sexes, uro-gynecological complications are often clinically unsuspected because of the dominant intestinal or systemic symptoms. Knowledge of their manifestations and cross-sectional imaging appearances is necessary to recognize and report them, since correct medical or surgical treatment choice with appropriate specialist consultation allows to prevent further complications. Besides uncomplicated urinary tract infections that usually do not require imaging, urolithiasis and pyelonephritis represent the most commonly encountered urinary disorders: although very useful, use of computed tomography (CT) should be avoided whenever possible, to limit lifetime radiation exposure. Hydronephrosis due to ureteral inflammatory entrapment and enterovesical fistulization may result from penetrating CD, and require precise imaging assessment with contrast-enhanced CT to ensure correct surgical planning. Representing the majority of genital complication, ano- and rectovaginal fistulas and abscesses frequently complicate perianal inflammatory CD and are comprehensively investigated with high-resolution perianal MRI acquired with phased-array coils, high-resolution T2-weighted sequences and intravenous contrast. Finally, rare gynecological manifestations including internal genital fistulas, vulvar and male genital involvement are discussed.

Contrast media extravasation represents a not unusual problem in radiological practice. Incidence, patient-, and procedure-related risk factors, pathogenesis, and clinical manifestations of extravasation injuries are discussed with a review of recent literature, and a practical preventive approach is proposed. A diagnostic and therapeutic protocol, to be applied whenever contrast extravasation is detected, includes radiographic assessment of compartmentalization, antidote application, local care, and clinical follow-up; indications for surgical consultation and adverse event reporting are provided.

Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the established surgical therapy for familial adenomatous polyposis (FAP) and refractory ulcerative colitis (UC). Despite general patient satisfaction with preserved fecal continence, this procedure is associated with a significant long-term morbidity approaching 70% after 10 years, and with a non-negligible rate of pouch failure leading to removal and permanent ileostomy. Following a concise description of the surgical technique, the normal imaging appearance of the ileal "pouch" reservoir at pelvic CT and MRI is explained. Since awareness of their imaging appearances is needed for a correct diagnosis, we discuss and illustrate common and unusual pouch-related complications, including pouchitis and irritable pouch disease; anastomotic leakages and pelvic abscess collections; fistulas involving the ano-perianal region, urinary bladder, vagina, perineal skin, and subcutaneous planes; anal stenosis and small-bowel obstruction. In our experience, pelvic contrast-enhanced MRI has proven invaluable for the diagnostic assessment of patients with suspected pouch-related complications, allowing differentiation of uncomplicated pouchitis from pelvic sepsis, the latter requiring aggressive therapy and possible even in patients with normal endoscopic findings.

A 66-year-old man was hospitalized because of ST elevation myocardial infarction (STEMI). During stent placement in the medium tract of the circumflex artery, conventional coronary angiography (CCA) depicted a fistulous tract between the left anterior descending artery (LAD) and the pulmonary trunk. After exclusion of coronary steal in the LAD territories by means of rest-stress myocardial perfusion scintigraphy (MPS) with Tc-99m, one-year follow up was established. Computed tomography coronary angiography (CTCA) was performed in order to better delineate fistula’s feature and provide a starting point for periodic evaluation. CTCA is less-invasive and more reproducible than conventional coronary angiography (CCA), therefore we suggest it as the modality of choice in the follow-up of coronary artery fistulas in asymptomatic patients.