Simona Ortori

Osteoid osteoma in atypical locations: The added value of dynamic gadolinium-enhanced MR imaging

PURPOSE To compare the results of dynamic gadolinium-enhanced magnetic resonance imaging (MRI), unenhanced MRI and computed tomography (CT), in terms of nidus conspicuity and diagnostic confidence of osteoid osteoma in atypical sites. MATERIALS AND METHODS CT and MR (nonenhanced T1- and T2-weighted and dynamic MRI) images of 19 patients with histologically proven osteoid osteoma located in atypical sites were retrospectively reviewed. Time-enhancement curves of the nidus and the adjacent bone marrow were generated. Images from each technique were scored for nidus conspicuity by two independent radiologists. Another blinded radiologist was asked to assess final diagnosis of the bone lesion on MR and CT images, independently. RESULTS In all cases, nidus contrast uptake started in the arterial phase and was higher compared to the surrounding bone marrow. Dynamic MRI significantly increased nidus conspicuity compared to nonenhanced MRI (P<.0001) and CT (P=.04). In 6/19 (31.6%) cases nidus conspicuity was higher at dynamic MRI compared to CT. Confident diagnosis of osteoid osteoma was achieved in all patients with MRI and in 10/19 (52.6%) patients with CT. CONCLUSION In patients with osteoid osteoma located in atypical sites, dynamic MRI increases nidus conspicuity, allowing confident diagnosis.

Endorectal coil MR imaging findings in hemospermia

The purpose of this study was to illustrate the spectrum of abnormalities found at endorectal coil magnetic resonance (MR) imaging in patients with hemospermia. Ninety patients aged between 23 and 71 years (mean age 41 years) presenting with hemospermia underwent evaluation with endorectal coil MR imaging at 1.5 T. Duration of hemospermia ranged between 5 days and 4 years (mean 15 months). MR examination protocol included T1-weighted spin-echo (SE) and T2-weighted fast SE MR images obtained in the sagittal, coronal, and axial planes. Abnormalities were observed on endorectal-coil MR images in 49 of 90 patients (54%). Blood within the seminal vesicle or the ejaculatory duct was recognized in 23 of 90 patients (25%). Dilatation of the seminal vesicles or the ejaculatory duct was observed in 31 of 90 patients (34%). Cystic lesions were identified in 14 cases, eight of which involved the utriculus and six the ejaculatory duct. Calculi within the seminal vesicles were depicted in seven patients. No malignant disease was demonstrated. In conclusion, despite the evidence that hemospermia is most often a benign and self-limiting condition, we found that endorectal coil MR imaging can detect abnormal findings in more than half of the patients, and may be helpful in assessing the level at which hemorrhage occurred and in defining the cause of the disease.

Contrast-enhanced three-dimensional MR angiography of neck vessels: does dephasing effect alter diagnostic accuracy?

Abstract. The aim of this study was to evaluate diagnostic accuracy of contrast-enhanced MRA (CEMRA) compared with digital subtraction angiography (DSA) in studying neck vessels of 48 patients. In three groups of patients, we used three MRA protocols differing for voxel size to assess if intravoxel dephasing effects could modify accuracy of CEMRA. Accuracy and correlation with DSA results were calculated in all patients and separately in the three groups. A qualitative analysis of the likeness between morphology of the stenosis in CEMRA and DSA images was also assessed. In all patients accuracy and agreement with DSA were 96% and k=0.85 in subclavian arteries, 96% and k=0.84 in vertebral artery, 97% and k=0.88 in common carotid arteries, and 94% and k=0.86 in internal carotid arteries. In the three groups accuracy and agreement with DSA did not show any significant difference. Qualitative analysis of CEMRA and DSA images revealed a better agreement in depicting the morphology of stenosis using a smaller voxel size. The CEMRA represents a powerful tool for the non-invasive evaluation of neck vessels. Overestimation trend of CEMRA is confirmed and the reduction of voxel size, decreasing the dephasing intravoxel effect, allows to have a better overlapping of stenosis morphology on CEMRA compared with DSA, but it does not yield diagnostic gain in the stenosis grading.

Contrast-enhanced three-dimensional MR angiography in the assessment of subclavian artery diseases

Abstract. The purpose of this prospective study was to determine the potential diagnostic value of 3D breath-hold contrast-enhanced MRA (CEMRA) in the evaluation of subclavian artery pathology, and to compare CEMRA and digital subtraction angiography (DSA) findings. The study group included 50 patients with suspicion of subclavian artery pathology: 40 suspected steno-occlusive disease and 10 different vascular anomalies. The MRA examinations were performed on a 1.5-T system using fast 3D sequences. A fixed dose of 40 ml Gd-DTPA was administered at 2 ml/s after previous bolus tracking. Images were analyzed to assess: subclavian depiction; luminal changes; collateral branches; and feeders of arterial venous malformations (AVM). A multireader blinded fashion was used. The CEMRA revealed an optimal agreement with DSA findings in the different types of diseases. Sensitivity and specificity were 90 and 95 %, respectively, in detecting steno-occlusive disease (including functional and arteritic stenoses), and 100 and 100 %, respectively, in cases of vascular anomalies (dilation, kinking, anomalous origin and AVM). Contrast-enhanced MRA can be proposed as a non-invasive, robust technique for imaging subclavian pathologies with high diagnostic performance.

Staging of pelvic lymph nodes in patients with prostate cancer: Usefulness of multiple b value SE-EPI diffusion-weighted imaging on a 3.0 T MR system

Purpose To evaluate the usefulness of diffusion-weighted imaging (DWI) with a multiple b value SE-EPI sequence on a 3.0 T MR scanner for staging of pelvic lymph nodes in patients with prostate cancer candidate to radical prostatectomy and extended pelvic lymph node dissection (PLND). Materials and methods Institutional review board approval was obtained and written informed consent was taken from all enrolled subjects. A series of 26 patients with pathologically proven prostate cancer (high or intermediate risk according to D’Amico risk groups) scheduled for radical prostatectomy and PLND underwent 3 T MRI before surgery. DWI was performed using an axial respiratory-triggered spin-echo echo-planar sequence with multiple b values (500, 800, 1000, 1500 s/mm2) in all diffusion directions. ADC values were calculated by means of dedicated software fitting the curve obtained from the corresponding ADC for each b value. Fitted ADC measurements were performed at the level of proximal and distal external iliac, internal iliac, and obturator nodal stations bilaterally. Lymph node appearance was also assessed in terms of short axis, long-to-short axis ratio, node contour and intranodal heterogeneity of signal intensity. Results A total of 173 lymph nodes and 104 nodal stations were evaluated on DWI and pathologically analysed. Mean fitted ADC values were 0.79 ± 0.14 × 10−3 mm2/s for metastatic lymph nodes and 1.13 ± 0.29 × 10−3 mm2/s in non-metastatic ones (P < 0.0001). The cut-off for fitted ADC obtained by ROC curve analysis was 0.91 × 10–3 mm2/s. A two-point-level score was assigned for each qualitative parameter, and the mean grading score was 6.09 ± 0.61 for metastastic lymph nodes and 5.42 ± 0.79 for non-metastatic ones, respectively (P = 0.001). Using a score threshold of 4 for morphological, structural, and dimensional MRI analysis and a cut-off value of 0.91 × 10–3 mm2/s for fitted ADC measurements of pelvic lymph nodes, per-station sensitivity, specificity, PPV, NPV and diagnostic accuracy were 100%, 7.9%, 15.6%, 100% and 21.3%, and 84.6%, 89.5%, 57.9%, 97.1% and 88.8%, respectively. Conclusions 3.0T DWI with a multiple b value SE-EPI sequence may help distinguish benign from malignant pelvic lymph nodes in patients with prostate cancer.

Thigh magnetic resonance imaging for the evaluation of disease activity in patients with idiopathic inflammatory myopathies followed in a single center.

Introduction: In patients with idiopathic inflammatory myopathies (IIM), magnetic resonance imaging (MRI) has been proposed as a useful tool for diagnosis and follow‐up. It may identify muscle inflammation (edema) and fatty infiltration for evaluation of disease activity and damage. Little information is available on the role of MRI in assessment of large cohorts of adult patients with IIM. Methods: Fifty‐one patients underwent MRI of the thigh muscles, laboratory tests, and clinical evaluation, including Physician Global Assessment (PGA) of myositis activity and the Manual Muscle Test 8 (MMT8). Results: Muscle edema correlated significantly with creatine kinase values (P = 0.017) and PGA (P < 0.001). A significant correlation between edema and MMT8 values (P = 0.025) was observed when patients with muscle fatty infiltration were excluded. With respect to clinical diagnosis, the sensitivity of MRI was 92.3%, and specificity was 83.3%. Conclusions: MRI appears to provide additional information that complements clinical and biochemical examinations. Muscle Nerve 54: 666–672, 2016

Time-resolved contrast-enhanced magnetic resonance angiography (CEMRA) of the left atrium–pulmonary veins complex with half dose of intravenous gadolinium-based contrast agent. Technical feasibility and comparison with a conventional CEMRA, full contrast dose protocol

PURPOSE To evaluate feasibility and image quality of time-resolved contrast-enhanced magnetic resonance angiography (CEMRA) of the left atrium-pulmonary veins (LA-PV) complex with half dose of intravenous gadolinium-based contrast agent (GBCA) in patients candidate to percutaneous radiofrequency ablation of atrial fibrillation. METHODS AND MATERIALS Fifty-seven patients underwent CEMRA of the LA-PV complex on a 1.5T MRI scanner. On 24/57 patients, a conventional fast-spoiled gradient-echo (FSPGR) CEMRA acquisition was run using 0.2 mL/kg of 0.5M GBCA at 2 mL/s flow rate (protocol A), while in 33/57 patients a time-resolved multiphase CEMRA sequence (Time-Resolved Imaging of Contrast KineticS, TRICKS) was performed after intravenous injection of 0.1 mL/kg of the same GBCA at 3 mL/s flow rate (protocol B). Contrast enhancement was measured in the LA (LAe) and in the PA (PAe), and the LAe/PAe ratio was calculated. Diagnostic quality of Maximum Intensity Projection (MIP), Volume Rendering (VR), and Virtual Endoscopy (VE) reconstructions was also assessed visually using a semiquantitative score. RESULTS LAe was comparable with both protocols, while PAe was lower with protocol B than with protocol A (p = 0.0217). Moreover, the LAe/PAe ratio was significantly higher with protocol B than with protocol A (p = 0.0044). Finally, image quality of MIP, VR, and VE reconstructions was significantly better with protocol B than with protocol A (p = 0.0005, p = 0.0001, and p = 0.005, respectively). CONCLUSIONS CEMRA of the LA-PV complex is feasible with TRICKS and half-dose GBCA and yields better separation between the LA-PV complex and the PA, as well as better image quality of MIP, VR, and VE reconstructions than a conventional FSPGR sequence performed with full GBCA dose.

Standardization of MRI and Scintigraphic Scores for Assessing the Severity of Bone Marrow Involvement in Adult Patients With Type 1 Gaucher Disease

OBJECTIVE MRI and (99m)Tc-sestamibi scintigraphy are used to estimate bone marrow infiltration in patients with Gaucher disease (GD), but comparison of data obtained at different institutions is difficult because different scores are employed for semiquantitative assessment. We developed normalized scores for comparing data both within a single method (MRI) and between different methods (MRI versus scintigraphy). MATERIALS AND METHODS We evaluated 51 patients with type 1 GD (26 women, 25 men; mean age ± SD, 36.3 ± 10.9 years old). T1- and T2-weighted turbo spin-echo sequences at 1.5 T served to derive the bone marrow burden score (0-16), the vertebra-disk ratio (VDR), the Terk score (0-3), and the Spanish-MRI score (S-MRI, 0-24). Scintigraphy was scored between 0 and 8. Each score was normalized into four categories: 0 = normal, 1 = mild, 2 = intermediate, 3 = severe involvement. Interobserver and intraobserver agreements were evaluated by kappa statistics; nonparametric statistics with Bonferroni correction assessed correlations among the various original and normalized scores. RESULTS Interobserver agreement was excellent for the original scores (κ = 0.730-0.843) and even more so for the normalized scores (κ = 0.775-0.940). Intraobserver agreement kappa values ranged from 0.753 to 0.937 for the original scores and 0.851 to 1.000 for the normalized scores. Highly significant correlations were found among the various original scores (r = 0.42-0.86, p values between 0.0296 and < 0.0001), except for VDR versus S-MRI and Terk. Normalization generally induced marginal reductions in statistical significance, whereas S-MRI versus VDR reached statistical significance with the normalized scores. CONCLUSION Our data indicate no significant loss of statistical information is caused by the normalization we employed. Our approach therefore facilitates comparison of different scores obtained in different institutions with different imaging modalities.