Under-reporting of cardiovascular findings on chest CT.

PURPOSE: It is unclear whether (and, to what extent) radiologists look at and report cardiovascular abnormalities on non-cardio-synchronized standard chest computed tomography (CT). In this study, the frequency and the reporting rate of cardiovascular findings in chest CT examinations were retrospectively assessed. MATERIALS AND METHODS: This study was approved by the institutional review board of each participating center. Four academic centers provided data on 447 subjects who underwent non-ECG-synchronized chest CT examinations for evaluating pulmonary fibrosis (161/447, 36 %), suspected pulmonary embolism (140/447, 31.3 %), or lung cancer staging (146/447, 32.7 %). A total of 220/447 (53.7 %) and 227/447 CT (46.3 %) examinations were evaluated and reported by junior and senior chest radiologists, respectively. Two radiologists with training in cardiac imaging reviewed the same chest CT images looking for the presence of incidental cardiovascular abnormalities using a preformatted score sheet. Inter-observer agreement was assessed using the kappa coefficient of agreement (k). RESULTS: Inter-observer agreement between the study reviewers was moderate to good (0.4-0.73) for most of the incidental cardiovascular findings. At least one incidental cardiovascular finding not documented in the original report was identified by the study reviewers in 225/409 (55 %) of chest CT examinations. A total of 168/266 (63.2 %) potentially clinically significant cardiovascular findings were unreported in the original reports of 177/447 (39.6 %) subjects (p < 0.0001). Senior radiologists tended to more frequently report coronary artery calcification (p = 0.0006), cardiac valves calcification (p = 0.0003), and ascending aorta enlargement (p = 0.01) compared to junior radiologists. CONCLUSIONS: Several cardiovascular abnormalities can be reliably identified on standard chest CT. Yet, they are often under-reported, even when they might be relevant to the patient's work-up.

Myocardial perfusion defects in scleroderma detected by contrast-enhanced cardiovascular magnetic resonance.

PURPOSE: The authors investigated whether contrast-enhanced cardiovascular magnetic resonance (CMR) imaging may be used to detect early cardiac involvement in patients with systemic sclerosis (SSc). MATERIALS AND METHODS: Twenty-six SSc patients (nine with diffuse cutaneous SSc and 17 with limited cutaneous SSc) and 13 sex- and age-matched healthy controls (HC) were studied. Contrast-enhanced CMR allowed the analysis of first-pass images (areas of hypo-enhancement indicating perfusion defects) and delayed images (persistent hyper-enhancement indicating fibrosis). Clinical variables including disease duration and presence of major visceral complications of SSc were investigated in each patient. RESULTS: Perfusion defects were detected in 53.8 % of SSc patients but in none of the HC. Perfusion abnormalities were detected in 28.6 % of SSc patients with disease duration less than 2 years and in 29.2 % of asymptomatic SSc patients. Delayed contrast enhancement was present in 25 % of SSc patients but not in HC. All patients with delayed contrast enhancement showed first-pass hypoperfusion. Right ventricular wall thickness was significantly increased in all SSc patients when compared to HC (p < 0.001); a similar trend was observed when SSc patients without pulmonary arterial hypertension were analysed (p < 0.04). A trend to lower end-diastolic and end-systolic right ventricular volumes in SSc versus HC was observed (p < 0.05 and p < 0.04, respectively). CONCLUSIONS: Myocardial hypoperfusion is common in SSc and occurs early in the course of the disease. Co-localisation of perfusion defects and delayed contrast enhancement indicative of fibrosis suggests that myocardial hypoxia may play a role in the pathogenesis of myocardial fibrosis.

Magnetic resonance imaging (MRI) artefacts in hip prostheses: a comparison of different prosthetic compositions.

PURPOSE: The purpose of the study was to compare the artefacts produced by different hip prostheses on magnetic resonance imaging (MRI). MATERIALS AND METHODS: An identical MRI protocol was used to perform a quali-quantitative in vitro evaluation of artefacts caused by different hip prosthetic materials at different field strengths: prosthesis number 1, composed of cobalt-chrome-molybdenum (head and stem); prosthesis number 2, composed of ceramic (head) and titanium (stem); prosthesis number 3, composed of cobalt-chrome (head) and titanium (stem). All prostheses were imaged with both a clinical 1 Tesla (T) (Signa Horizon, General Electrics) and 1.5 T (Achieva, Philips) MRI system, using spin echo (SE) and gradient echo (GRE) sequences: sagittal T1 SE, coronal T2 fast SE (FSE), axial T1 SE, axial T2 FSE, sagittal T2 GRE, axial T2* GRE, coronal T1 GRE, axial T1 GRE. The artefacts produced by each prosthesis were assessed in each sequence at the different field strengths, by measuring the two longest diameters of the artefact in each section and sequence and comparing them to the actual diameters so as to obtain a ratio expressing the effective degree of artefact. RESULTS: Cobalt-chrome produced the largest artefacts both in SE (1.73 at 1 T and 2.37 at 1.5 T) and GRE sequences (2.8 at 1 T and 3.06 at 1.5 T) followed by titanium (SE, 1.6 at 1 T, 2.13 at 1.5 T; GRE, 2 at 1 T, 2.94 at 1.5 T) and cobalt-chrome-molybdenum (SE, 1.51 at 1 T, 1.67 at 1.5 T; GRE, 2.13 at 1 T and 2.48 at 1.5 T); ceramic produced the smallest artefacts in all sequences (SE, 1.0 at 1 T and 1.18 at 1.5 T; GRE, 1.3 at 1 T and 1.22 at 1.5T). Increasing the magnetic field strength, titanium showed the greatest variations in artefact size, and ceramic the smallest ones. CONCLUSIONS: The composition of prosthetic implants is decisive in determining the quality of MR imaging.

Automatic detection, localization, and volume estimation of ischemic infarcts in noncontrast computed tomographic scans: method and preliminary results.

OBJECTIVES: Sensitivity of noncontrast computed tomography (NCCT) in detecting hyperacute (< 8 hours) and acute (< 24 hours) cerebral infarction is low. We propose an automatic method to detect and localize ischemic infarct and to assess its volume from a single NCCT scan. MATERIALS AND METHODS: The method automatically determines attenuation value ranges of cerebrospinal fluid and white and gray matter, separates the brain scan into the left and right hemispheres, and by analyzing hemisphere attenuation value distributions using percentile difference ratios, it detects, localizes, and quantifies the infarct without its segmentation. The method performance was evaluated on 576 patients with clinically confirmed stroke through NCCT scans acquired at 4 centers to measure how it matched with that of experts in detection, localization, and assessment of infarct volume. The time from the onset of symptoms ranged from 1.5 to 72 hours for 450 scans and more than 72 hours for 82 scans, most with pathologic findings in addition to cerebral infarction; the time was unavailable for 44 scans. In addition, the method was compared with the novice's (with 52 scans) and experienced readers' infarct detection (with 21 × 2 scans) in early ischemia detection (with the time from the onset of symptoms ranging from 1.5 to 7 hours). RESULTS: The method matches 100% the expert's infarct detection when chronic infarcts, leukoaraiosis cases, and infarct volumes less than 2 cm (determined by detection accuracy simulation) are excluded from the analysis. For all cases excluding infarct volumes less than 2 cm, the method detection accuracy is 95.7%. Overall, the method detection accuracy is 83.2%. The early method detection accuracy (≤ 3 hours) is 78.4%. The novice detection accuracy is 27.8% (≤ 3 hours), 37.5% (3 < to ≤ 8 hours), and 77.8% (> 8 hours), whereas the expert detection accuracy for these cases is 100%. Moreover, the method detected all 21 early infarcts, of which 15 were missed by the stroke experts and 14 of 15 were missed by a general radiologist. The method performs automatic analysis in approximately 7 seconds. CONCLUSIONS: The results demonstrate potential benefits of our method for enhancing expert's performance because it quickly localizes the infarct and detects cases missed by experts, and it is to be considered as an aid in the emergency department because it substantially outperforms novice readers (100% vs 27%) in infarct detection on NCCT.

Functional MRI examination of visual pathways in patients with unilateral optic neuritis.

The relations between brain areas involved in vision were explored in 8 patients with unilateral acute optic neuritis using functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). In all patients monocular stimulation of affected and unaffected eye elicited significantly different activation foci in the primary visual cortex (V1), whereas the foci evoked in the middle temporal visual area (area V5) were similar in size and in delay of blood-oxygen-level-dependent response. DTI analysis documented lower white matter anisotropy values and reduced fibre reconstruction in the affected compared with the unaffected optic nerves. The preserved activation of area V5 observed in all our patients is an interesting finding that suggests the notion of a different sensitivity of the optic pathways to inflammatory changes.

Stenting right main bronchus with montgomery T tube for upper lobe ventilation.

The involvement of the right main bronchus (RMB) along with the upper lobe bronchus and bronchus intermedius by malignant tumor is frequently encountered. However, the use of a stent for palliation of airway stenosis of the RMB might obstruct upper lobe orifice and pose complications such as atelectasis or recurrent pneumonia. We report the use of modified Montgomery T tube in a 78-year-old man with neoplasm of the RMB by placing the tracheostomy arm of the T tube in the upper lobe bronchus to maintain its patency.

Performance of imaging modalities in diagnosis of liver metastases from colorectal cancer: a systematic review and meta-analysis.

Surgery of liver metastases can be effective, and the appropriate selection of surgical candidates relies first on imaging. Different techniques are available, but information on their relative performance is unclear. The aim of this overview is to assess the imaging modality performance in the diagnosis of colorectal cancer (CRC) liver metastases. MEDLINE and EMBASE were searched for articles published from January 2000 to August 2008. Eligible trials had to be conducted on patients with diagnosis/suspicion of CRC liver metastases, comparing more than two modalities among MRI, computed tomography (CT), positron emission tomography using fluoro-18-deoxyglucose (FDG-PET), ultrasonography (US). Pooled estimates of sensitivity, specificity were calculated and pair-wise comparisons were performed. Of 6030 screened articles, 25 were eligible. Sensitivity and specificity on a per-patient basis for US, CT, MRI, and FDG-PET were 63.0% and 97.6%, 74.8% and 95.6%, 81.1% and 97.2, and 93.8% and 98.7%, respectively. On a per-lesion basis, sensitivity was 86.3%, 82.6%, 86.3%, and 86.0%, respectively. Specificity was reported in few studies. MRI showed a better sensitivity than CT in per-patient (odds ratio [OR]: 0.69; 95% confidence interval [CI]: 0.47-0.99; P = 0.05) and in per-lesion analysis (OR: 0.66; 95% CI: 0.55-0.80; P < 0.0001). In per-lesion analysis, the difference was higher when liver-specific contrast agents were administered. Available evidence supports the MRI use for the detection of CRC liver metastases.

Acute aortic syndromes: Role of multi-detector row CT.

Acute thoracic aortic syndromes encompass a spectrum of emergencies including aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and aneurysm rupture. All these life-threatening conditions require prompt diagnosis and appropriate management. To date multi-detector row Computed Tomography represents a valuable diagnostic tool especially in the emergency setting. This paper focus on the use of multi-detector row Computed Tomography in the evaluation of acute thoracic aortic syndromes and illustrates the key imaging findings related to each disease.

Suspected pulmonary embolism and deep venous thrombosis: A comprehensive MDCT diagnosis in the acute clinical setting.

Both pulmonary arterial and peripheral venous sides of venous thromboembolism (VTE) can now be efficiently and safely investigated by multi-detector CT (MDCT) at the same time by a combined CT angiography/CT venography protocol. In the emergency setting, the use of such a single test for patients suspected of suffering from VTE on a clinical grounds may considerably shorten and simplify diagnostic algorithms. The selection of patients to be submitted to MDCT must follow well-established clinical prediction rules in order to avoid generalized referral to CT on a generic clinical suspicion basis and excessive population exposure to increased ionizing radiation dose, especially in young patients. Clinical and anatomical wide-panoramic capabilities of MDCT allow identification of underlying disease that may explain patients' symptoms in a large number of cases in which VTE is not manifest. The analysis of MDCT additional findings on cardiopulmonary status and total thrombus burden can lead to better prognostic stratification of patients and influence therapeutic options. Some controversial points such as optimal examination parameters, clinical significance of subsegmentary emboli, CT pitfalls and/or possible falsely positive diagnoses, and outcome of untreated patients in which VTE has been excluded by MDCT without additional testing, must of course be taken into careful consideration before the definite role of comprehensive MDCT VTE "one-stop-shop" diagnosis in everyday clinical practice can be ascertained.

The many faces of aortic dissections: Beware of unusual presentations.

Aortic dissection is gaining recognition in Western societies, and it is being diagnosed with increasing frequency. New diagnostic imaging modalities, longer life expectancy, as well as the increase in the number patients suffering from hypertension have all contributed to the growing awareness of aortic dissection. Nevertheless, as many as 30% of patients ultimately diagnosed with acute dissection are first thought to be suffering from something else. The increased availability and use of multidetector computed tomography has led to the incidental discovery of aortic dissection in very different settings. This article focuses on unusual presentations of painless aortic dissection. It is important for radiologists to remember that aortic dissections may present in different ways, not only as an acute, critical fatality but also with subtle, unusual signs and symptoms, which apparently do not seem to be strictly related to aortic diseases.

Magnetic resonance cholangiopancreatography in primary sclerosing cholangitis in children.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic cholestatic syndrome of unknown aetiology. Diagnosis is based on clinical and laboratory data in conjunction with imaging of the biliary tree using endoscopic retrograde cholangiopancreatography (ERCP). OBJECTIVE: : To evaluate the clinical usefulness of MR cholangiopancreatography (MRCP) in the diagnosis of PSC in children. MATERIALS AND METHODS: Twenty-one children with clinical and laboratory suspicion of PSC were enrolled. MRCP was performed using a superconductive system with a phased-array coil. Rapid acquisition with relaxation enhancement (RARE) T2-weighted and half-Fourier single-shot turbo-spin-echo (HASTE) sequences were used. The distribution and extent of biliary tree changes were evaluated and classified according to Majoie's classification. A comparison between MRCP and ERCP was performed blind in all cases to evaluate the usefulness of MRI. RESULTS: In 13 cases (62%), MRCP showed abnormalities of the biliary tree which were considered positive for PSC, while in 8 cases there were no signs of PSC. Both MRCP and ERCP correctly identified changes in 13 cases and excluded abnormalities in 5. MRCP had a sensitivity of 81%, specificity of 100%, negative predictive value of 62%, positive predictive value of 100% and an accuracy of 85%. CONCLUSIONS: MRCP can be proposed as the preliminary non-invasive imaging modality for the diagnosis of PSC in children.