Alfredo D'Andrea

Value of diffusion-weighted magnetic resonance imaging in the characterization of complex adnexal masses

AIMS AND BACKGROUND The aim of the study was to define the role of diffusion-weighted imaging in the characterization of adnexal complex masses, with particular regard to the distinction between benign and malignant lesions. Conflicting results on this topic have emerged from studies in the last decade, with a consequent substantial limitation to the use of this relatively novel technique in clinical practice. METHODS AND STUDY DESIGN Magnetic resonance imaging examinations performed on 91 patients with ovarian masses (56 benign, 35 malignant) were retrospectively evaluated by two observers unaware of the final histopathological diagnosis. Diffusion-weighted sequences with b values of 0, 500 and 1000 were performed in all cases, and apparent diffusion coefficient maps were automatically generated. The signals of both the cystic and solid components of the ovarian masses were evaluated on T2-weighted and diffusion-weighted images acquired with a b value of 1000. Apparent diffusion coefficient values were measured in all cases. RESULTS With regard to the solid components, hypointensity on both the T2-weighted and diffusion-weighted images has proved to be a reliable indicator of benignancy. In contrast, hyperintensity on both sequences was suggestive of malignancy. Signal intensity of the cystic components and apparent diffusion coefficient values of both components have not proven useful in characterization of the masses. CONCLUSIONS Only the definition of the signal intensities on diffusion-weighted images obtained with the use of high b values on the solid component of a complex adnexal mass is useful to characterize an ovarian mass as benign or malignant.

Pancreatic tumors imaging: An update

Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up.

Painless but problematic

An asymptomatic 61 year old woman was referred for eval-uationofasuspectedinguinalhernia.Shehadavoluminousindolent pubic mass that had developed over several years(Figure, A). Investigation with 64-slice multidetector-rowcomputed tomography (CT) demonstrated a peripherallyhypervascularizedmass,16cminmaximumdiameter,sup-plied by the left pudendal artery and the left anterior obtu-rator artery, which arose, in this patient, from the left infe-rior epigastric artery; these arteries shunted into multipleveins that drained into the pudendal vein (Figure, B and C;Video Clip). Preoperative digital subtraction angiographyconfirmed the feeding arteries and enabled presurgical em-bolization with Spongostan, a hemostatic agent, and coils(Figure, D). Surgery ensued 48 hours later.

Score 3 prostate lesions: a gray zone for PI-RADS v2.

Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) does not offer a precise guidance on the clinical management (biopsy or not biopsy) for PI-RADS v2 score 3 lesions. Lesion volume calculated on biparametric MRI (bpMRI) [T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI)] by introducing a cut-off of 0.5 mL, allows to distinguish the lesions assigned by the multiparametric MRI (mpMRI) to the category PI-RADS v2 score 3 in two subgroups: a) Indolent or low risk lesions with volume <0.5 mL, and b) Significant or high risk lesions with volume ≥0.5 mL. For mpMRI lesions assigned to PI-RADS v2 score 3, we suggest the following management: 1) Subgroup a (low-risk lesion): Clinical surveillance (accurate evaluation of age and clinical informations, periodic monitoring of prostate specific antigen value and repeated bpMRI 1 year later); 2) Subgroup b (high-risk lesion): Targeted biopsy. The proposed management would reduce the use of unnecessary biopsies and increase the diagostic yield of significant prostate cancer of approximately 50% and 30% respectively. These approaches encourage the radiologist to adopt MRI lesion volume to improve PI-RADS v2 and to optimize the management of PI-RADS v2 score 3 lesions.

[Evaluation with multislice CT of the hilar pulmonary nodules for probable infiltration of vascular-bronchial structures].

Tumor stage is an important prognostic factor for patients suffering from lung cancer, because it affects the type of therapeutic treatment to be implemented. Computed tomography is the imaging method of choice for the staging of lung cancer, and for central neoplasm, it is essential to assess any possible involvement of bronchovascular structures that may affect operability. We report our experience based on the use of reconstruction algorithms for the study of the relationship between tumor, bronchi and adjacent vessels.

Is contrast enhancement needed for diagnostic prostate MRI

Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) provides clinical guidelines for multiparametric magnetic resonance imaging (mpMRI) [T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)] of prostate. However, DCE-MRI seems to show a limited contribution in prostate cancer (PCa) detection and management. In our experience, DCE-MRI, did not show significant change in diagnostic performance in addition to DWI and T2WI [biparametric MRI (bpMRI)] which represent the predominant sequences to detect suspected lesions in peripheral and transitional zone (TZ). In this article we reviewed the role of DCE-MRI also indicating the potential contribute of bpMRI approach (T2WI and DWI) and lesion volume evaluation in the diagnosis and management of suspected PCa.

Simplified Prostate Imaging Reporting and Data System for Biparametric Prostate MRI: A Proposal

OBJECTIVE We describe our institutional experience using a simplified Prostate Imaging Reporting and Data System (PI-RADS) based on biparametric prostate MRI. We discuss two important controversies: the use of gadolinium-based contrast agents and the management of PI-RADS category 3 lesions. CONCLUSION Our simplified PI-RADS identifies four categories and suggests management strategies for each. The simplified PI-RADS can be an effective system to facilitate multidisciplinary cooperation and to improve the management of suspected prostate cancer.

Value of triphasic MDCT in the differentiation of small renal cell carcinoma and oncocytoma

Introduction Although differentiation between benign and malignant small renal tumors (≤4 cm) is still difficult, it is a demand for decision making and determining the treatment strategy. Our aim is to evaluate the role of multidetector row computed tomography (MDCT) in the differentiation of small renal clear cell carcinoma (RCC) and renal oncocytoma (RO). Methods We reviewed triphasic computed tomographic (CT) scans performed in 43 patients diagnosed with RCC (n = 23) and RO (n = 21). After an unenhanced CT phase of the upper abdomen, triple-phase acquisition included a cortico-medullary phase (CMP), a nephrographic phase (NP), and a pyelographic phase (PP), and lesions were evaluated both qualitatively and quantitatively. Results RCCs were hypervascular in 13 cases and hypovascular in 10 cases, while ROs were hypervascular in nine cases and hypovascular in 12 cases. Mean attenuation values (MAVs) for hypervascular RCCs and hypervascular ROs on unenhanced examination were 34.0 ± 7.1 and 31.3 ± 8.1 HU, respectively. Enhancement in CMP was 173.1 ± 45.2 HU for RCCs and 151.1 ± 36.0 HU for ROs and a gradual wash-out in NP (148.8 ± 34.3 and 137.1 ± 33.9 HU for RCCs and ROs, respectively) and in PP (98.2 ± 36.0 HU for RCCs and 79.4 ± 21.5 HU for ROs) was observed. MAV for hypovascular RCCs and hypovascular ROs on unenhanced examination were 32.4 ± 12.0 and 28.9 ± 8.0 HU, respectively. Both hypovascular RCCs and ROs showed a statistically significant difference in each post contrastographic phase. Conclusions Absolute attenuation and the quantitative amount of the enhancement were not strong predictors for RO and RCC differentiation.