Magnetic resonance imaging:Is there a role in clinical management for acute ischemic colitis?

AIM:To validate the utility of magnetic resonance imaging(MRI) for the clinical management of acute ischemic colitis(IC).METHODS:This is a magnetic resonance(MR) prospective evaluation of 7 patients who were proved to have acute IC on the basis of clinical,endoscopic and computed tomography(CT) findings and who were imaged in our institution between February 2011 and July 2012.The mean age of the patients was 72.28 years.Abdominal CTs were obtained using a 64-detector row configuration for all patients with un-enhanced and contrast-enhanced scans,in the late arterial phase(start delay 45-50 s) and in the portal venous phase(start delay 70-80 s).The MR examinations were performed using a 1.5T superconducting magnet,using Fast Imaging Employing Steady State Acquisition and T2-weighted fast-recovery fast-spin echo sequences in axial and coronal plane.CT and MRI examinations were analysed for the presence of colonic abnormalities and associated findings.RESULTS:Segmental involvement was seen in 6 patients(85.71%),with a mean length of involvement of 412 mm(range 145.5-1000 mm).Wall thickness varied between 6 mm and 17.5 mm(mean 10.52 mm) upon CT examinations and from 5 to 15 mm(mean 8.8 mm) upon MR examinations.The MRI appearance of the colonic wall varied over the time:TypeⅠappearance with a 3 layer sandwich sign was seen in 5 out of 12 examinations(41.66%),patients underwent MR within a mean of 36 h(ranging from 1 to 54 h) after the CT examination.Type Ⅱ and Ⅲ appearance with a 2 layer sign,was seen in 4 examinations(33.33%),patients underwent MR within a mean of 420.5 h(ranging from 121 to 720 h) after the CT examination.In the remaining three MRI examinations,performed within a mean of 410 h(ranging from 99.5 to 720 h) the colonic wall appeared normal.CONCLUSION:MRI,only using precontrast images,may be used as a substitute for invasive procedures in diagnosis and follow-up of acute IC.

Incidental extravascular findings in computed tomographic angiography for planning or monitoring endovascular aortic aneurysm repair: Smoker patients, increased lung cancer prevalence?

AIM To validate the feasibility of high resolution computed tomography(HRCT) of the lung prior to computed tomography angiography(CTA) in assessing incidental thoracic findings during endovascular aortic aneurysm repair(EVAR) planning or follow-up.METHODS We conducted a retrospective study among 181 patients(143 men, mean age 71 years, range 50-94) referred to our centre for CTA EVAR planning or followup. HRCT and CTA were performed before or after 1 or 12 mo respectively to EVAR in all patients. All HRCT examinations were reviewed by two radiologists with 15 and 8 years experience in thoracic imaging. The results were compared with histology, bronchoscopy or follow-up HRCT in 12, 8 and 82 nodules respectively. RESULTS There were a total of 102 suspected nodules in 92 HRCT examinations, with a mean of 1.79 nodules per patient and an average diameter of 9.2 mm(range 4-56 mm). Eightynine out of 181 HRCTs resulted negative for the presence of suspected nodules with a mean smoking history of 10 pack-years(p-y, range 5-18 p-y). Eighty-two out of 102(76.4%) of the nodules met criteria for computed tomography follow-up, to exclude the malignant evolution. Of the remaining 20 nodules, 10 out of 20(50%) nodules, suspected for malignancy, underwent biopsy and then surgical intervention that confirmed the neoplastic nature: 4(20%) adenocarcinomas, 4(20%) squamous cell carcinomas, 1(5%) small cell lung cancer and 1(5%) breast cancer metastasis); 8 out of 20(40%) underwent bronchoscopy(8 pneumonia) and 2 out of 20(10%) underwent biopsy with the diagnosis of sarcoidosis.CONCLUSION HRCT in EVAR planning and follow-up allows to correctly identify patients requiring additional treatments, especially in case of lung cancer.

Follow-up of endovascular aortic aneurysm repair:Preliminary validation of digital tomosynthesis and contrast enhanced ultrasound in detection of medium- to long-term complications

AIM: To validate the feasibility of digital tomosynthesis of the abdomen(DTA) combined with contrast enhanced ultrasound(CEUS) in assessing complications after endovascular aortic aneurysm repair(EVAR) by using computed tomography angiography(CTA) as the gold standard.METHODS: For this prospective study we enrolled 163 patients(123 men; mean age, 65.7 years) referred for CTA for EVAR follow-up. CTA, DTA and CEUS were performed at 1 and 12 mo in all patients, with a maximum time interval of 2 d.RESULTS: Among 163 patients 33 presented complications at CTA. DTA and CTA correlated for the presence of complications in 32/33(96.96%) patients and for the absence of complications in 127/130(97.69%) patients; the sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) and accuracy of DTA were 97%, 98%, 91%, 99%, and 98%, respectively. CEUS and CTA correlated for the presence of complications in 19/33(57.57%) patients and for the absence of complications in 129/130(99.23%) patients; the sensitivity, specificity, PPV, NPV and accuracy of CEUS were 58%, 99%, 95%, 90%, and 91%, respectively. Sensitivity, specificity and accuracy of combining DTA and CEUS together in detecting EVAR complications were 77%, 98% and 95%, respectively.CONCLUSION: Combining DTA and CEUS in EVAR follow-up has the potential to limit the use of CTA only in doubtful cases.