ESGAR consensus statement on the imaging of fistula-in-ano and other causes of anal sepsis.

OBJECTIVES: To develop imaging guidelines for patients with fistula-in-ano and other causes of anal sepsis. METHODS: An expert group of 13 members of the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) used a modified Delphi process to vote on a series of consensus statements relating to the imaging of patients with potential anal sepsis. Participants first completed a questionnaire to gather practice information and to help frame the statements posed. RESULTS: In the first round of voting, the expert group scored 51 statements of which 45 (88%) achieved immediate consensus. The remaining 6 statements were redrafted following input from the expert group and consensus achieved for all during a second round of voting, including an additional statement drafted. No statement was rejected due to a lack of consensus. After redrafting to improve clarity, 53 individual statements were presented. CONCLUSION: These expert consensus statements can be used to guide appropriate indication, acquisition, interpretation and reporting of medical imaging for patients with potential fistula-in-ano and other causes of anal sepsis. KEY POINTS: • Medical imaging, notably magnetic resonance imaging, is used widely for the diagnosis and monitoring of fistula-in-ano and other causes of anal and perianal sepsis. • While the indexed medical literature is clear that diagnostic accuracy is potentially excellent, this depends on competent image acquisition and interpretation. • In order to facilitate this, the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) has produced expert consensus guidelines regarding the imaging of fistula-in-ano and related conditions.

Prevalence of acute reactions to iopromide: postmarketing surveillance study of 74,717 patients.

BACKGROUND: Iodinated X-ray contrast media (CM) are recognized worldwide to be among the safest and most widely used injectable drugs. However, adverse drug reactions (ADRs) may still occur, ranging in severity from minor disturbances to severe and potentially fatal complications. PURPOSE: To prospectively determine the incidence and characteristics of acute ADRs during clinical utilization of a single nonionic monomeric contrast agent, iopromide, in routine radiological practice in a large number of nonselected patients. MATERIAL AND METHODS: 74,717 patients were enrolled in a prospective international postmarketing surveillance registry with iopromide (Ultravist; Bayer Schering Pharma AG, Berlin, Germany). A standardized questionnaire was used to collect the following patient information from 762 centers in 27 countries: baseline demographics, risk factors, premedication regimen, type of examination, route of injection, volume and selected concentration of iopromide, and overall tolerance to CM (utilizing specific criteria and descriptors). RESULTS: The overall rate of ADRs, including tolerance indicators (TI) (i.e., heat sensation and pain at the injection site), was 2%; when TIs were excluded, the rate was 1.5%. Fourteen serious adverse reactions were reported (rate 0.02%), of which none were fatal. There was a higher incidence of ADRs among women and for the age group ranging between 18 and 30 years. Patients with established risk factors, such as a history of previous CM reaction or allergic diathesis (7.4% and 4.1%, respectively), were at an increased risk for developing an ADR when compared to patients without risk factors (1.2%). The incidence of ADRs was not altered by the use of premedication. CONCLUSION: The safety of iopromide in routine clinical practice was shown to be comparable to the published safety profiles of other nonionic iodinated contrast agents. Adverse drug reaction rates were affected by age, gender, and risk factors (especially previous CM reactions or allergies), but not by premedication.

Subspecialized radiology review at multidisciplinary pancreas conference: impact on patient management.

PURPOSE: At our tertiary medical center, multidisciplinary subspecialists meet twice a week during a CME-accredited conference to discuss oncologic and non-oncologic patients with pancreatic diseases at which time a subspecialized abdominal staff radiologist reinterprets the patient's relevant imaging studies. This study assesses the changes in patient management due to imaging reinterpretation during multidisciplinary pancreas conference (MPC). MATERIALS AND METHODS: In this retrospective, IRB-approved, HIPAA-compliant study, imaging studies of all patients discussed at MPC between July 1 and December 31, 2015 were assessed for technical adequacy, and original reports analyzed for congruency with reinterpretation. Management measures included change in diagnosis, clinical stage, treatment, or workup. Additional data were obtained on referring services affected and their resultant change in practice. Changes in surgical resectability, surgical approach, or delayed operative dates were noted for surgeons. Changes in chemotherapeutic or radiation oncology regimens as well as decisions for additional imaging, laboratory workup, or histologic evaluation were also recorded. RESULTS: A total of 252 patients were included (54.4% males, 45.6% females, mean age 63.71 years). Relevant imaging consisted of 142 abdominal CT scans, 112 abdominal MRI scans, 1 abdominal ultrasound, and 1 nuclear medicine octreotide study of which 69.4% were performed in-house. Image quality was deemed appropriate in 95.2%. Cases presented included solid pancreatic malignancies (n = 140; 55.6%), cystic pancreatic lesions (n = 41; 16.3%), acute and chronic inflammatory conditions (n = 52; 20.6%), and miscellaneous entities (n = 10; 4.0%); 9 (3.6%) cases were normal. Image reinterpretation was congruent with original reports in 56.7%, with minor, moderate, and major discrepancies occurring in 9.5, 26.2%, and 7.5% of cases, respectively. Incongruent reinterpretation was predominantly due to perceptional errors (false-negative reports due to missed findings) and interpretative errors (false-positive results due to over-reporting or misclassification of diagnoses). Services most commonly affected included surgical oncology, radiology, and gastroenterology at 16.7%, 13.1%, and 12.7% of cases, respectively. Management changes included a change in diagnosis in 8.7%, change in clinical stage in 8.7%, change in treatment in 17.9%, and further workup needed in 19.0% of patients, respectively. No change in management occurred in the remaining 61.5% of cases. CONCLUSIONS: Subspecialized abdominal radiologist reinterpretation in the context of more comprehensive patient information heavily impacts the multidisciplinary management of patients with pancreatic disorders. Further efforts are needed to solidify the abdominal radiologist's role in the multidisciplinary clinical setting.

Noninvasive multidetector computed tomography enterography in patients with small-bowel Crohn's disease: is a 40-second delay better than 70 seconds?

BACKGROUND: Multidetector computed tomography (MDCT) enterography combines neutral enteric contrast with intravenously administered contrast material. The optimal intravenous (IV) contrast material protocol has still not been established. PURPOSE: To determine the optimal delay time to image patients with small-bowel Crohn's disease during MDCT enterography. MATERIAL AND METHODS: After oral administration of 1350 ml of neutral contrast medium, 26 patients with small-bowel Crohn's disease underwent MDCT enterography;scans were obtained 40 s (enteric phase) and 70 s (parenchymal phase) after IV administration of 100 ml of iodinated contrast material. Three radiologists, blinded to clinical and pathological findings, independently and retrospectively evaluated each scan in two separate reading sessions for the presence or absence of CT features of Crohn's disease activity. The interobserver agreement was evaluated, and the efficacy of each phase in detecting active disease in the terminal ileum for each reader was determined. The gold standard was pathology (n=13), endoscopy (n=3), and clinical evaluation (n=10). RESULTS: No statistically significant difference was present between the enteric and the parenchymal phase for each reader in each segment regarding the presence or absence of CT features of Crohn's disease. The interobserver agreement for the presence of five main features of active Crohn's disease in the terminal ileum ranged from poor to excellent.The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for active Crohn's disease in the terminal ileum ranged from 40 to 90%, 88 to 100%, 70 to 94%, 44 to 100%, and 69 to 96%, respectively. There was no statistical difference between the two phases for each reader. CONCLUSION: MDCT enterography in patients with suspected active Crohn's disease can be obtained at either 40 s or 70 s after IV contrast material.

Imaging of extraspinal musculoskeletal tuberculosis.

Tuberculosis (TB) is still a major cause of significant morbidity and mortality despite universal availability of effective chemotherapy. The emergence of multidrug-resistant mycobacteria along with a worldwide increase in HIV infection has led to a recent surge in the number of patients with TB. TB involves both pulmonary and extrapulmonary sites. Tuberculous spondylitis is the most common form of musculoskeletal TB and accounts for approximately 50% of cases. Extraspinal musculoskeletal TB is among the least common manifestations of TB. It shows a predilection for joints and para-articular areas while isolated soft tissue TB occurs extremely rare. A non-specific, often indolent clinical presentation in conjunction with its low prevalence constitutes obstacles for diagnosis. The differential diagnosis of extraspinal musculoskeletal TB consists of degenerative processes, inflammatory and infectious conditions, primary neoplasms, and metastatic lesions. Early diagnosis and treatment is of utmost importance to prevent serious joint and bone destruction. Radiological assessment of patients with musculoskeletal TB is often the key to adequate diagnosis and early treatment. The purpose of this manuscript is to review the imaging features of extraspinal musculoskeletal TB and to focus on the magnetic resonance imaging (MRI) characteristics of this pathology.

CT scan of the liver.

Since its inception, CT scan has had a dominant role in hepatic imaging. Recent advances including helical CT scan and bolus-triggered scan initiation software packages have had a significant impact. Issues regarding volume, rate of administration, and type of intravenous contrast are being distilled. Workstations for three-dimensional data reconstructions are producing images that compete with conventional angiography in certain areas, while angiographically assisted CT scan is being refined in others.

Magnetic resonance imaging of the exocrine pancreas.

The currently available MRI, techniques that are used to perform imaging of the pancreas are reviewed. A basic pancreas examination includes: fat-suppressed breath-hold T1-weighted and respiratory triggered or breath-hold T2-weighted fast sequences The use of dynamic MRI with both extracellular gadolinium chelates and specific contrast agents is stressed in the evaluation of exocrine pancreatic diseases. It is concluded that an "all-in-one" approach including MR angiography of the pancreatic vessels and MR cholangiopancreatography of the biliopancreatic ductal system, confirmed by further studies, is presumably the most cost-effective imaging technique in the evaluation of a vast array of exocrine pancreatic diseases.

Hepatic adenomatosis: MR imaging features.

Hepatocellular adenomas are rare benign liver neoplasms that commonly occur in women with a history of oral contraceptives intake for more than 2 years. Hepatic adenomatosis is characterized by the presence of multiple adenomas, arbitrarily > than 10, involving both lobes of the liver, without any history of steroid therapy or glycogen storage disease. Although the adenomas in liver adenomatosis are histologically similar to other adenomas, liver adenomatosis appears to be a separate clinical entity. Adenomas in hepatic adenomatosis may be of the inflammatory, hepatocyte nuclear factor 1alpha-mutated, or beta-catenin-mutated subtype, and accordingly show variable imaging appearances. Hepatic adenomatosis carries the risk of impaired liver function, hemorrhage and malignant degeneration. We report a case with the inflammatory subtype of hepatic adenomatosis in a 39-year-old woman with liver steatosis. The magnetic resonance imaging features using extracellular gadolinium chelates and hepatocyte-targeted contrast agents are described.

Acute intestinal anisakiasis: CT findings.

Small bowel anisakiasis is a relatively uncommon disease that results from consumption of raw or insufficiently pickled, salted, smoked, or cooked wild marine fish infected with Anisakis larvae. We report a case of intestinal anisakiasis in a 63-year-old woman presenting with acute onset of abdominal complaints one day after ingestion of raw wild-caught herring from the Northsea. Computed tomography (CT) scanning demonstrated thickening of the distal small bowel wall, mucosa with hyperenhancement, mural stratification, fluid accumulation within dilated small-bowel loops and hyperemia of mesenteric vessels. In patients with a recent history of eating raw marine fish presenting with acute onset of abdominal complaints and CT features of acute small bowel inflammation the possibility of anisakiasis should be considered in the differential diagnosis of acute abdominal syndromes.

Gastrointestinal tract wall visualization and distention during abdominal and pelvic multidetector CT with a neutral barium sulphate suspension: comparison with positive barium sulphate suspension and with water.

OBJECTIVE: When examining patients with contrast-enhanced multidetector-row CT, we determined if the stomach and small bowel were visualized and distended better with a neutral barium sulphate suspension than with positive barium sulphate suspension or water. MATERIALS AND METHODS: After obtaining approval from our institutional review board, 156 patients (women: 84; mean age: 54 yrs) with no history of gastrointestinal tract disease were randomized prospectively to receive orally either 900 ml of neutral (0.1% w/v) barium sulphate suspension (n = 53), 900 ml of positive (2.1% w/v) barium sulphate suspension (n = 53), or 900 ml of water (n = 50), prior to undergoing contrast-enhanced abdominal and pelvic multidetector-row CT. Two independent radiologists evaluated the stomach, and small bowel, for luminal distension and wall visualization, using a five point scale. Results were compared using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The walls of the stomach, and small bowel were visualized better in patients who were administered neutral barium sulphate suspension than those who were administered either positive barium sulphate suspension (p < 0.01) or water (p < 0.01). In patients who received neutral barium sulphate suspension, the stomach and small bowel were distended better compared to patients administered water (p < 0.01); the stomach, duodenum, and ileum were distended better compared to patients administered positive barium sulphate suspension (p < 0.05). CONCLUSIONS: When examining patients with intravenous contrast-enhanced abdominal and pelvic multidetector-row CT, orally administered neutral barium sulphate suspension allows the gastrointestinal tract to be visualized and distended better than either positive barium sulphate suspension, or water.

Tuberculous adenitis: comparison of CT and MRI findings with histopathological features.

Our aim was to investigate the relationship between the various histopathological features and the CT and MRI findings in routinely submitted histopathological specimens for the diagnosis of tuberculous lymphadenopathy. Twelve formalin-fixed, paraffin-embedded tissue blocks from ten patients who were clinically suspected of having tuberculous lymphadenopathy were evaluated. We assessed the presence of histopathological features including granuloma formation, caseous necrosis, and presence of Langhans-type giant cells, calcifications, fibrosis or normal lymphoid tissue. We performed polymerase chain reaction (PCR)-based assay for mycobacterial DNA and Ziehl-Neelsen staining for acid-fast bacilli (AFB). Findings were compared with those of CT and MRI, including signal intensities on unenhanced MR images, lymph node homogeneity, attenuation values on contrast-enhanced CT and enhancement patterns on MRI. Based on CT and MRI findings, four lymph node types could be defined: (1) homogeneous nodes, visible on both pre- and post-contrast images and corresponding histopathologically to granulation tissue without or with minimal caseation necrosis (n = 2); (2) heterogeneous nodes, showing heterogeneous enhancement patterns with central non-enhancing areas and corresponding to minor or moderate intranodal caseation/liquefaction necrosis (n = 3); (3) nodes showing peripheral rim enhancement and corresponding to moderate or extensive intranodal caseation/liquefaction necrosis (n = 5); (4) heterogeneous nodes showing intranodal hyperdensities on CT and hypointense areas on T1- and T2-weighted images and corresponding to fibrosis and calcifications (n = 2). On CT and MRI, the findings reflect different stages of the tuberculous process. Imaging findings depend on the presence and the degree of granuloma formation, caseation/liquefaction necrosis, fibrosis and calcifications.

CT and MR imaging of gastrointestinal tuberculosis.

The purpose of this study was to describe the CT and MR imaging findings of tuberculosis of the gastrointestinal tract. Abdominal and pelvic CT scans and MRI studies of 6 patients with histopathological and microbiological proven intestinal tuberculosis were reviewed by two radiologists in consensus. Location and pattern of bowel wall involvement, signal intensities in relation to the normal bowel wall, pattern of enhancement and associated abdominal abnormalities were evaluated. Gastrointestinal tract tuberculosis may be limited to one bowel segment, with the cecum and ileocecal valve as the predominant site of disease, or may involve multiple bowel segments. Asymmetric thickening of the bowel wall is a common finding. Associated findings include pericecal and mesenteric fat stranding, regional lymphadenopathy showing peripheral, heterogeneous and/or homogeneous enhancement patterns and less commonly, tuberculous 'dry plastic' peritonitis. On magnetic resonance (MR) imaging, tuberculous bowel involvement results in intermediate decreased signal intensities on T1-weighted images, and intermediate increased, slight heterogeneous signal intensities on T2-weighted images. On contrast-enhanced images, slight heterogeneous enhancement is seen.

Tuberculosis: epidemiology, manifestations, and the value of medical imaging in diagnosis.

Mycobacterial infections have been shown to be increasing in number worldwide, mainly due a global increase in developing countries, the increased number of patients with HIV infection and AIDS disease worldwide, an increasing number of elderly patients and the emergence of multidrug resistant tuberculosis. Inhalation is the predominant pathway of Mycobacterium tuberculosis (M. tuberculosis) infection, making pulmonary tuberculosis the most common form of tuberculosis. Tuberculosis may arise either from a recent infection with M. tuberculosis, or from the reactivation of dormant bacilli, years or decades after initial infection. Extrapulmonary tuberculosis mainly results from reactivation of a tuberculous focus after hematogenous dissemination or lymphogenous spread from a primary, usually pulmonary focus. Tuberculosis may demonstrate a variety of radiological features depending on the organ site involved and may mimick other pathologies. The final diagnosis of tuberculous disease mainly depends on the detection of the causative organism on histopathological examination, culture and polymerase chain reaction-based assay for mycobacterial DNA on material obtained during bronchoscopic washings, fine needle aspiration cytology (FNAC) or biopsy.

Clinical and radiological deterioration in a patient with AIDS.

Paradoxical clinical deterioration of miliary tuberculosis, characterized by pulmonary and abdominal manifestations, is reported in a patient with the acquired immunodeficiency syndrome, after initiation of treatment with highly active antiretroviral therapy. Paradoxical reaction was attributed to partial restoration of cell-mediated immunity related to highly effective antiretroviral therapy. Because tuberculosis has a high prevalence in HIV patients and tuberculosis is often characterized by miliary spreading of disease in these patients, it is important to recognize this phenomenon.

Abdominal tuberculous lymphadenopathy: MRI features.

The aim of this study was to describe the MRI features of abdominal tuberculous lymphadenopathy. MRI studies of 13 patients with abdominal tuberculous lymphadenopathy were reviewed with regard to anatomic distribution and size. Signal intensities, in relation to abdominal wall muscle, on unenhanced T1- and T2-weighted images and patterns of contrast enhancement of lymphadenopathy were evaluated in each patient. In each patient, the largest lymph node with the same imaging characteristic was evaluated. The upper paraaortic region was the most common site of involvement (n=12 patients), followed by the lesser omentum (n=10 patients), the anterior pararenal space (n=9 patients), the lower paraaortic area (n=8 patients), the small bowel mesentery (n=6 patients), the greater omentum (n=2 patients) and the originating site of the inferior mesenteric artery (n=2 patients). The mean lymph node size was 1.8 cm (range 0.5-5 cm). The overall mean lymph node number per patient was 16 (range 2-50). A total of 41 lymph nodes were evaluated in 13 patients. On T2-weighted images, 40 lesions were hyperintense and one lesion was isointense. Nine hyperintense lesions showed a hypointense peripheral rim and seven internal heterogeneïty. Perinodal T2-hyperintensity was present in 23 lesions. The latter finding was valid for all patients. On T1-weighted images, 30 lesions were hypointense and 11 isointense. Nine hypointense lesions demonstrated a hyperintense peripheral rim, and six were heterogeneous. Contrast-enhanced fat-suppressed T1-weighted images demonstrated predominant peripheral enhancement in 28 lesions: (1) peripheral uniform, thin (n=19); (2) thick irregular, complete (n=3); and (3) conglomerate group of nodes showing peripheral and central areas of rim enhancement (n=6). Heterogeneous and homogeneous enhancement was present in ten and three lesions, respectively. Combinations of enhancing patterns in the same nodal group and different nodal groups were seen in eight and nine patients, respectively. Abdominal tuberculous lymphadenopathy may show a variety of signal intensities and patterns of contrast enhancement on MRI. Lymphadenopathy, hypointense on T1-weighted, hyperintense on T2-weighted images with perinodal hyperintensity, and predominant peripheral rimlike enhancement may suggest the diagnosis of tuberculosis.

Tuberculosis of the pancreas: MRI features.

OBJECTIVE: The purpose of this study was to describe the MRI features of tuberculosis of the pancreas. CONCLUSION: Pancreatic tuberculosis can be focal or diffuse. If focal, it presents as a sharply delineated mass located in the pancreatic head, showing heterogeneous enhancement. Lesions are hypointense on fat-suppressed T1-weighted images and a mixture of hypo- and hyperintense on T2-weighted images. The appearances of common bile duct and main pancreatic duct are normal. Diffuse involvement is characterized by pancreatic enlargement with narrowing of the main pancreatic duct and heterogeneous enhancement. Signal intensity abnormalities indicating diffuse involvement include hypointensity on fat-suppressed T1-weighted images and hyperintensity on T2-weighted images.

Tuberculosis of the spine: CT and MR imaging features.

Tuberculosis (TB) remains endemic in most of the developing countries. However, a resurgence of tuberculosis has also been reported in the past decades in developed countries, not only in the lungs, but also in extrapulmonary sites, e.g. the vertebral column. Vertebral TB is most often found in the lower thoracic and upper lumbar regions. Diagnosis is often difficult; clinical findings are usually non-specific and radiologic features may mimic those of other bacterial, fungal, inflammatory and neoplastic diseases. However, recognition and understanding of the radiological findings may help in diagnosis. Two distinct patterns of vertebral tuberculosis may be seen: the classic finding of spondylodiscitis, characterized by destruction of two or more contiguous vertebrae and opposed end plates, disk infection, and commonly a paraspinal mass or collection. The second pattern, increasing in frequency, is a atypical form of spondylitis without disk involvement.The value of CT and MR imaging are discussed in the diagnostic workup of vertebral tuberculosis. A positive culture or histopathologic analysis of CT-guided needle aspiration or biopsy specimens is required in the absence of pulmonary manifestations of tuberculosis for definitive diagnosis and adequate treatment.

Vascular involvement secondary to tuberculosis of the abdomen.

Although involvement of the abdomen is a common site of extrapulmonary tuberculosis, involvement of abdominal vessels with complications is rare after infections with Mycobacterium tuberculosis (M. tuberculosis). Vascular complications may result from direct involvement by M. tuberculosis of the vascular wall or may occur as a consequence of local spreading from a tuberculous mass. We describe the imaging findings in two patients with proven tuberculosis of the abdomen and significant vascular complications. In one patient, "dry plastic" peritonitis and tuberculous lymphadenopathy at the level of the porta hepatis with subsequent encasement and compression of the portal vein resulted in prestenotic dilatation and varicose formation in the upper abdomen. In the other patient, bulky necrotic tuberculous lymphadenopathy, located at the splenic hilum, resulted in encasement with stenosis of the splenic vessels and subsequent splenic infarction.

Imaging of diffuse liver disease.

Advances in imaging technology and development of liver-specific contrast agents have significantly increased the role of radiology in the detection and characterization of processes diffusely involving the liver. Tailored magnetic resonance imaging (MRI) sequences allow an accurate detection of many storage and metabolic diseases, such as iron overload disorders and steatosis (fatty liver). Faster scanning techniques available with both computed tomography (CT) and MRI provide, by assessing contrast dynamics, sufficient information for the characterization of diffuse neoplastic and vascular disorders. Characteristic changes in attenuation on CT, signal intensity on MRI, and enhancing features can be used to diagnose specific diffuse diseases such as candidiasis, diffuse/multifocal hepatocellular carcinoma, and schistosomiasis. Although an overlap in imaging findings still exists, familiarity with the imaging features of uncommon disorders such as Wilson's disease, amyloidosis, and sarcoidosis may be diagnostic in the proper clinical setting. This review focuses on the current role of imaging in the detection and characterization of diffuse liver disorders. Recent developments that have amplified the role of noninvasive diagnostic evaluation of these conditions are especially highlighted.