320-row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC): effect of 100 kV versus 120 kV on image quality and dose exposure.

PURPOSE: To compare the impact of a 100 kV tube voltage protocol to 120 kV in terms of image quality and radiation dose by a 320 row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC). MATERIALS AND METHODS: Using a propensity matched analysis we compared a group of 135 patients scanned using a 100 kV tube voltage protocol with a group of 135 subjects scanned employing a 120 kV tube voltage setting. In all subjects the heart rate (HR) was <65 bpm and all CT scans were acquired using a prospective ECG gating and AEC strategy. Mean effective radiation dose and subjective and objective (Noise or N, signal to noise ratio or SNR, contrast to noise ratio or CNR) image quality, were evaluated. Subjective quality was assessed by two experienced radiologists using a 5-point scale (0: non diagnostic-4: excellent) using the 15-segment American Heart Association (AHA) coronary artery classification. RESULTS: Mean effective dose and noise were non significantly different between the two groups: mean effective dose was 2.89 ± 0.7 mSv in the 100 kV group and 2.80 ± 0.57 mSv in the 120 kV group (p = 0.25) while noise was 28.9 ± 3.3 in the 120 kV group and 29.05 ± 3.6 in the 100 kV group (p = 0.72). Both SNR and CNR were significantly higher in the 100 kV group than in the 120 kV group. This data agrees with the evidence that subjective quality was significantly higher in the 100 kV group in the middle and distal segmental classes. CONCLUSION: Our study shows that, in using a 320 row CCTA with AEC strategy it is better to employ a 100 kV tube voltage protocol because compared to 120 kV tube voltage setting, it appears to significantly improve both subjective and objective image quality without decreasing the mean effective radiation dose.

Magnetic resonance imaging (MRI) of the lumbar spine with dedicated G-scan machine in the upright position: a retrospective study and our experience in 10 years with 4305 patients.

PURPOSE: To evaluate the pathological changes of the lumbar spine and the instability of the lumbar intervertebral joints observed in patients with low back pain, with the study of the transition from supine to orthostatic position through the use of dedicated MRI-G-scan machine. MATERIALS AND METHODS: Within 10 years, 4305 patients, aged between 21 and 80 years old, with history of low back pain with or without sciatica, underwent MRI examinations in upright and in supine position. The open MRI-scanner used is Esaote G-scan, which enables the acquisition of images in supine and standing positions. The used sequences were sagittal T2-weighted FSE, T1-weighted SE and axial 3D HYCE. Patients were divided into two groups: "negatives", with no changes in the two positions (supine and upright), and "positives", with MRI modifications of imaging in upright position. RESULTS: Orthostatic examination showed MRI changes in 2870 out of 4305 (66.6%) patients, including 1252 males and 1618 females. CONCLUSIONS: The G-scan is useful to assess instability of the lumbar spine detecting hidden modifications of protrusions and/or herniated discs already present in the supine position. It is also helpful in assessing the presence or modification of spondylolisthesis and lumbar canal stenosis.

T2 shine-through phenomena in diffusion-weighted MR imaging of lumbar discs after oxygen-ozone discolysis: a randomized, double-blind trial with steroid and O2-O3 discolysis versus steroid only.

PURPOSE: To evaluate the discal morpho-structural changes as predictive sign in the clinical outcome after Ozone Therapy in lumbar disc herniation using the T2 shine-through effect in DWI. METHODS: One hundred and fifty-four patients suffering from lumbosciatica (89 men and 65 women; range 23-62 years) were included in previous MR study performed with FSE-T2 and T2-fat, SE-T1 and DWI sequences and were randomly assigned to two groups. Seventy-seven patients (Control Group) underwent conservative treatment with intraforaminal injection of steroid and anesthetic. The remaining 77 patients (Study Group) underwent the same treatment with the addiction of oxygen-ozone (O2-O3). During the coming 6 months, an MRI follow-up with the same sequences was performed. An intervertebral disc volumetric analysis (IDVA), DWI signal score and post treatment clinical outcome evaluation were performed for an assessment of hernia reduction. χ (2) test, Student's t test and analysis of covariance were used for comparison of variables. RESULTS: In the Study Group, 58 over 77 patients had a successful outcome (Responders). In the Responders group, DWI T2 shine-through effect was present during MRI follow-up and in particular in 53 of 77 patients in the 6 months of follow-up (P < 0.05). Moreover, in the same group was present a statistically significant discs' shrinkage in the sixth month of follow-up (P < 0.05) as showed by IDVA. CONCLUSIONS: T2 shine-through effect in DWI is present before morphological disc reduction and moreover could be considered as a predictive sign of response to oxygen-ozone treatment.

Assessment of dose exposure and image quality in coronary angiography performed by 640-slice CT: a comparison between adaptive iterative and filtered back-projection algorithm by propensity analysis.

PURPOSE: This study was performed to confirm, by propensity score matching, whether the use of adaptive-iterative dose reduction (AIDR 3D) with a built-in automatic exposure control system provides clinical and dosimetric advantages with respect to the traditional filtered back-projection (FBP) algorithm without automatic exposure modulation. MATERIALS AND METHODS: A total of 200 consecutive patients undergoing coronary computed tomography (CT) angiography on a 640-slice CT scanner were studied. A protocol with exposure parameters based on patient body mass index (BMI) and with images reconstructed using FBP (group A) was compared with a protocol with images acquired using tube current decided by an automatic exposure control system and reconstructed using AIDR (group B). Mean effective dose and image quality with both objective and subjective measurements were assessed. RESULTS: Mean effective dose was 23.6 % lower in group B than in group A (2.56 versus 3.34 mSv; p < 0.0001). Noise was significantly lower in group B with consequent higher signal-to-noise (SNR) and contrast-to-noise (CNR) (p < 0.0001) compared with group A. Subjective quality parameters were also significantly higher in group B. CONCLUSIONS: Comparative analysis by propensity score matching confirms that AIDR 3D with automatic exposure control is able to reduce significantly the mean radiation dose and improve the image quality compared with traditional FBP without exposure modulation.

Advances in imaging and in non-surgical salvage treatments after radiorecurrence in prostate cancer: what does the oncologist, radiotherapist and radiologist need to know?

OBJECTIVES: In this article the state of art the of prostate cancer (Pca) imaging and non-surgical salvage treatments (STs) is surveyed in order to explore the impact of imaging findings on the identification of radiorecurrent Pca after external beam radiotherapy (EBRT). METHODS: A computerised search was performed to identify all relevant studies in Medline up to 2012. Additional articles were extracted based on recommendations from an expert panel of authors. RESULTS: Definitive EBRT for Pca is increasingly used as treatment. After radiorecurrent Pca, non-surgical STs are emerging and shifting from investigational status to more established therapeutic options. Therefore, several scientific societies have published guidelines including clinical and imaging recommendations, even if the timing, efficacy and long-term toxicity of these STs have to be established. In some measure, accurately delineating the location and the extent of cancer is critical in selecting target lesions and in identifying patients who are candidates for STs. However, there is increasing awareness that anatomical approaches based on measurements of tumour size have substantial limitations, especially for tumours of unknown activity that persist or recur following irradiation CONCLUSIONS: To date, the main focus for innovations in imaging is the combination of excellence in anatomical resolution with specific biological correlates that depict metabolic processes and hallmarks at the tumour level. The emergence of new molecular markers could favour the development of methods that directly determine their presence, thereby improving tumour detection. KEY POINTS: Imaging may influence therapeutic decisions during non-surgical STs. MRI findings correlate with parametric maps derived from multiple functional techniques. Non-surgical salvage treatments allow local tumour control in patients with radiorecurrent PCa.

Low Dose versus Standard Single Heartbeat Acquisition Coronary Computed Tomography Angiography.

PURPOSE: The aim of this study was to compare image quality and mean radiation dose between two groups of patients undergoing coronary computed tomography angiography (CCTA) using a 640-slice CT scanner with two protocols with different noise level thresholds expressed as standard deviation (SD). MATERIALS AND METHODS: Two-hundred and sixty-eight patients underwent a CCTA with 640 slice CT scanner. In the experimental group (135 patients), an SD 51 protocol was employed; in the control group (133 patients), an SD 33 protocol was used. Mean effective dose and image quality with both objective and subjective measures were assessed. Image quality was subjectively assessed using a five-point scoring system. Segments scoring 2, 3, and 4 were considered having diagnostic quality, while segments scoring 0 and 1 were considered having nondiagnostic quality. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between the two groups as well as the effective radiation dose (ED) was finally assessed. RESULTS: Comparative analysis considering diagnostic quality (2, 3, and 4 score) and nondiagnostic (score 0 and 1) quality demonstrated that image quality of SD 51 group is not significantly lower than that of S33 group. The noise was significantly higher in the SD 51 group than in the SD 33 group (P < 0.0001). The SNR and CNR were higher in the SD 33 group than in SD 51 group (P < 0.0001). Mean effective dose was 49% lower in the SD 51 group than in SD 33 group; indeed mean effective dose was 1.43 mSv ± 0.67 in the SD 51 group while it was 2.8 mSv ± 0.57 in the SD 33 group. CONCLUSION: Comparative analysis shows that using a 640-slice CT with a 51 SD protocol, it is possible to reduce the mean radiation dose while maintaining good diagnostic image quality.

Pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance identifies very early cardiac involvement in systemic sclerosis patients of recent onset.

OBJECTIVE: To evaluate occult cardiac involvement in asymptomatic systemic sclerosis (SSc) patients by pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance (CMR), for a very early identification of patients at higher risk of cardiac-related mortality. METHODS: Sixteen consecutive patients with definite SSc, fulfilling the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria in less than 1 year from the onset of Raynaud's phenomenon, underwent pharmacological stress, rest perfusion and delayed enhancement CMR. At enrollment, no patient showed signs and/or symptoms suggestive for cardiac involvement. No patient showed traditional cardiovascular risk factors. Both the 12-lead electrocardiogram examination and echocardiographic evaluation did not show any alterations in our cohort. RESULTS: Stress perfusion defects of left ventricle were detected in six out of 16 (37.5%) patients and these defects did not match with the coronary flow distribution. The results showed the presence of two different patterns of stress perfusion defects: sub-endocardial and/or a midmyocardial. The presence of stress perfusion defects did not correlate with any clinical feature of enrolled patients. CONCLUSION: Myocardial stress perfusion defects may be detected early by pharmacological stress perfusion CMR, a reliable and sensitive technique for the noninvasive evaluation of SSc heart disease, in patients with SSc of recent onset. These defects seem to be independent from traditional risk factors and associated comorbidities, suggesting they are a specific hallmark of the disease.

Magnetic resonance imaging and magnetic resonance spectroscopy in a young male patient with anti-N-methyl-D-aspartate receptor encephalitis and uncommon cerebellar involvement: A case report with review of the literature.

We report a case of a 17-year-old man presenting with new onset psychiatric symptoms. Magnetic resonance imaging (MRI) and proton magnetic resonance (MR) spectroscopy revealed some lesions in the right cerebellar hemisphere and ipsilateral cerebellar tonsil suggestive of encephalitis. An extensive workup was negative for both infectious and neoplastic diseases and he was afterward diagnosed with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. This disorder is an autoimmune encephalitis, highly lethal but curable, predominantly found in young female with ovarian teratoma. He received methylprednisolone. His clinical findings gradually improve and he made a complete recovery. Accordingly, repeated brain MRI and proton MR spectroscopy showed a gradual reduction of the lesions; MRI taken six months after starting therapy showed complete resolution of the lesions. Our case shows that, although rare, anti-NMDAR encephalitis should be considered also in young men for whom a rapid onset of psychiatric neurological disorders cannot be explained by more frequent causes. Our report underlines also the usefulness of MRI and proton MR spectroscopic findings in the diagnosis and follow-up of this disease.

Image quality and radiation dose of single heartbeat 640-slice coronary CT angiography: a comparison between patients with chronic atrial fibrillation and subjects in normal sinus rhythm by propensity analysis.

OBJECTIVES: To evaluate image quality and radiation dose of single heartbeat 640-slice coronary CT angiography (CCTA) in patients with chronic Atrial Fibrillation (cAF) in comparison with subjects in normal sinus rhythm. METHODS: A cohort of 71 patients with cAF was matched with 71 subjects in normal sinus rhythm (NSR) and HR≤65 bpm using a matched by propensity analysis. All subjects underwent a single heartbeat CCTA with prospective gating. In subjects with cAF, we manually established the acquisition of data only from a single heartbeat. Mean effective dose and image quality, with both objective and subjective measures, were assessed. RESULTS: 96.4% of all segments in the cAF group had diagnostic image quality. The rate of subjects with at least one non-diagnostic segment was 14% and 2.8% (p=0.031) in the cAF and NRS groups, respectively. In the cAF group, the percentage of patients with at least one non-diagnostic segment for acquisition HR≤72 was 1.8% (1/55), and it did not significantly differ from the NSR group (2.8%; 2/71) (p=1.0). Objective quality parameters did not show a statistically significant difference between the two groups. The mean effective dose was 4.24±1.24 mSv in the cAF group and 2.67±0.5 mSv in the sinus rhythm group (p<0.0001) with an increase by 59% in the cAF group with respect to the SNR group. CONCLUSIONS: A single heartbeat acquisition protocol with a 640-slice prospectively ECG-triggered CT angiography may be feasible in patients with cAF and HR below 72 bpm at the CT acquisition, although mean effective dose of this protocol in cAF group was 59% higher than in sinus rhythm one. In patients with cAF and a heart rate higher than 72 bpm, CCTA tends to have more movement-associated artefacts.

Magnetic resonance imaging of AMS (Aneurysm of the Membranous Septum), review of the literature and case report.

Aneurysm of the Membranous Septum (AMS) is a rare cardiac disease, mostly associated with other cardiac anomalies, very rare in the absence of other congenital heart defects. A prompt diagnosis is important, due to severe potential complications, but remain challenging. Most of the cases were earlier diagnosed using ventriculography, but, with the availability of echocardiography and cardiovascular magnetic resonance (CMR), this disease can be accurately assessed non-invasively. We report a case of a 62 years old female patient, without other cardiac congenital disease, who was incidentally diagnosed, by means of CMR with a true and isolated AMS. Our report underlines CMR usefulness in AMS diagnosis, thanks to accurate evaluation (both morphologic and functional) provided by this diagnostic tool, which is able to demonstrate clearly the presence of AMS (aneurysm of the membranous septum) and depict its features.

An Unusual Case of Ascending Pancreatitis with Mediastinal Involvement: A Case Report with CT and MRI Findings.

Fluid collections are common findings of pancreatitis and spread, more often, along preferential drainage pathways in the abdomen. In some rare cases, fluid collections may spread towards extra-abdominal sites like the mediastinum leading to the formation of mediastinal collections. We present the case of a 52-years-old man with pain in the right upper quadrant of the abdomen and mid-epigastrium lasting for some hours. Laboratory tests suggested a diagnosis of pancreatitis. CT and subsequent MRI revealed changes consistent with acute exacerbation on chronic pancreatitis spreading to the mediastinum and to the greater omentum. The patient received medical treatment and reported gradual improvement in his laboratory results and CT findings.

Progressive Multifocal Leukoencephalopathy Following Treatment with Rituximab in an HIV-Negative Patient with Non-Hodgkin Lymphoma. A Case Report and Literature Review.

Progressive multifocal leukoencephalopathy (PML) is a rare rapidly progressive demyelinating disease of the central nervous system caused by reactivation of latent John Cunningham (JC) polyomavirus (JCV) infection. We describe an unusual case of PML in a 54-year-old patient with follicular non-Hodgkin lymphoma who received rituximab plus cyclophosphamide, hydroxydaunorubicin, oncovicin and prednisolone (R-CHOP) therapy. She started to notice gradual progressive neurological symptoms about two months after completion of rituximab treatment and was therefore admitted to hospital. On admission, brain CT and MRI showed widespread lesions consistent with a demyelinating process involving the subcortical and deep white matter of the cerebral and cerebellar hemispheres. CT and MRI findings were suggestive of PML, and JC virus DNA was detected by polymerase chain reaction assay of the cerebrospinal fluid and serum. The patient was treated supportively but reported a progressive worsening of the clinical and radiological findings. Our report emphasizes the role of CT and MRI findings in the diagnosis of PML and suggests that PML should be considered in patients with progressive neurological disorders involving the entire nervous system and mainly the white matter, especially in the presence of previous immunomodulatory treatment or immunosuppression.