M Gabelloni

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.

Iodine Concentration and Optimization in Computed Tomography Angiography: Current Issues.

AbstractComputed tomography (CT) technology has seen a dramatic evolution in the recent past that has deeply changed the face of this diagnostic modality. Since the early days of helical single-slice and then multislice CT, CT angiography (CTA) has been one of the most technically demanding applications, both in terms of scanning technique and contrast medium (CM) injection protocol, due to the need to acquire a large amount of high-resolution data over a limited period corresponding to the peak contrast enhancement of the arterial system. Iodine concentration is one of the main determinants of arterial enhancement in CTA, and current low-osmolar and iso-osmolar nonionic CM for intravascular administration still come in a handful of molecules, but a relatively wide range of different iodine concentrations. This gives the opportunity to optimize CTA protocols as a function of several factors such as patient characteristics, CT technology, and CM features in an attempt to maximize the diagnostic yield of CTA examinations while considering patient safety and avoiding unnecessary extra costs. Our aim is to provide an up-to-date overview of the existing evidence on how changing iodine concentration can have an impact on CTA performance, especially with the use of state-of-the-art CT and power injector technology, in the perspective of improving patient care while minimizing overall exposure to iodinated CM and ionizing radiation.

Thrombosis of Kommerell’s diverticulum with subclavian steal phenomenon in a patient with non-small cell lung carcinoma under chemotherapy

Kommerell’s diverticulum (KD) is defined as a bulbous dilatation of the origin of an aberrant subclavian artery due to a remnant of the left fourth aortic arch. We report the case of an asymptomatic woman in whom progressive thrombosis of the KD extending to the prevertebral tract of an aberrant right subclavian artery was detected at multidetector computed tomography imaging for lung cancer staging performed before and after the beginning of chemotherapy. Reversed blood flow in the ipsilateral vertebral artery due to subclavian steal phenomenon was also observed by color Doppler ultrasound examination.

Preprocedural planning of transcatheter mitral valve interventions by multidetector CT: What the radiologist needs to know

Mitral regurgitation is the most common valve disorder in the Western world, and although surgery is the established therapeutic gold standard, percutaneous transcatheter mitral interventions are gaining acceptance in selected patients who are inoperable or at an exceedingly high surgical risk. For such patients, multidetector computed tomography (MDCT) can provide a wealth of valuable morphological and functional information in the preoperative setting. Our aim is to give an overview of the MDCT image acquisition protocols, post-processing techniques, and imaging findings with which radiologists should be familiar to convey all relevant information to the Heart Team for successful treatment planning.

Fulminant hepatic failure: a case report

Abdominal ultrasound showed hepatomegaly with irregular liver contour and diffuse heterogeneity of liver texture with multiple, ubiquitous hyperechoic and hypoechoic microand macronodules. Enlargement of the spleno-portomesenteric venous system and mildly enlarged celiac lymph nodes were also seen. An MRI examination of the abdomen was then performed, showing liver stucture completely subverted by multiple, diffuse, party confluent nodules with low signal intensity on T1-weighted images, mixed signal intensity on T2weighted images, and hypointensity compared to the surrounding liver tissue on contrast-enhanced fat suppressed T1-weighted images. Biopsy of liver lesions could not be carried out due to severe coagulopathy. The patient died of liver failure a few days later. Discussion: