Renato Cuocolo

Quantification of Myocardial Perfusion: SPECT

Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) is important for the management of patients with suspected or known coronary artery disease. Stress myocardial perfusion images may be interpreted by visual inspection or by quantitative analysis. The use of visual inspection alone may introduce considerable observer variability and clinical usefulness of myocardial perfusion imaging may not be consistently reproduced in many laboratories using visual analysis. Relative myocardial distribution of imaging agents on SPECT images can be quantified and compared with normal data files by computer processing. Quantification of myocardial perfusion images provides a reproducible measure of the extent of perfusion abnormalities and defect reversibility. The quantification of myocardial perfusion images improves not only the overall diagnostic yield but also enhances reliability, accuracy, confidence, and reproducibility of interpretation. This review illustrates the current status and the future perspectives of myocardial perfusion quantification by SPECT imaging.

Preliminary Results of a Simplified Breast MRI Protocol to Characterize Breast Lesions: Comparison with a Full Diagnostic Protocol and a Review of the Current Literature

RATIONALE AND OBJECTIVES This study aimed to investigate whether a simplified breast magnetic resonance imaging (MRI) protocol consisting of a localizer, one precontrast sequence, and three time-point postcontrast sequences (at 28 seconds, 84 seconds and 252 seconds after the contrast agent administration) is suitable for the characterization of breast lesions as compared to a full diagnostic protocol (FDP). This study also aimed to review the current literature concerning abbreviated breast MRI protocols and offer an alternative protocol. MATERIALS AND METHODS Breast magnetic resonance (MR) examinations with detected breast lesions of 98 patients were retrospectively evaluated. Two expert radiologists in consensus reviewed the simplified breast protocol (SBP) first and only thereafter the regular FDP, recording a diagnosis for each detected lesion for both protocols. Receiver operating characteristic curve analysis was performed to determine the diagnostic performance of the SBP compared to the standard FDP. A revision of the previously reported abbreviated breast magnetic resonance protocols was also carried out. RESULTS A total of 180 lesions were identified; of these, 110 (61%) were malignant and 70 (39%) were benign. Of the 110 malignant lesions, 86 (78%) were invasive ductal carcinoma, 18 (16%) were invasive lobular carcinoma, and 6 (6%) were ductal carcinoma in situ. Areas under the curve for the receiver operating characteristic curves for the SBP vs the FDP were equivalent (0.98 vs 0.99, respectively; P = 0.76). The SBP could be performed in approximately 6 minutes and 58 seconds, compared to 14 minutes and 48 seconds for the FDP. CONCLUSIONS An SBP protocol including a late postcontrast time point is accurate for the characterization of breast lesions and was comparable to the standard FDP protocol, allowing a potential reduction of the total acquisition and interpretation times.

Evidence for a differential interaction of buprenorphine with opiate receptor subtypes controlling prolactin secretion

We studied the effects of various doses of the opiate derivative buprenorphine on serum prolactin levels and whether these effects could be counteracted by pretreatment with the opiate receptor blocker naloxone. The administration of increasing doses of buprenorphine exerted a dual effect on serum prolactin levels. At low doses (3, 10 and 30 micrograms/kg) this agent increased serum prolactin levels. This effect disappeared with increasing doses (100 and 300 micrograms/kg), and at the highest doses (1000 and 3000 micrograms/kg) the levels of serum prolactin decreased. Naloxone (30 mg/kg) decreased serum prolactin levels and reversed both the stimulatory and the inhibitory action of buprenorphine. These data are compatible with the hypothesis that buprenorphine could interfere with two different, but inter-dependent receptors: at low doses the oripavine derivative could act at one receptor site to cause an increase of serum prolactin, whereas at higher doses it could interact with a second site of lower affinity that is responsible for the inhibition of prolactin secretion. When buprenorphine (at high doses) activates the lower affinity site, the interaction with this receptor counteracts and reverses the effects of the high affinity site. On the basis of this hypothesis, naloxone should block both receptors.

Biparametric Prostate MR Imaging Protocol: Time to Revise PI-RADS Version 2?

Editor: With great interest, we read the Letters to the Editor by Dr Scialpi and colleagues (1) in the January 2018 issue of Radiology and Drs Kaji and Inamura (2) in the February 2018 issue of Radiology commenting on the article by Dr Kuhl et al in the July 2017 issue of Radiology (3) about a possible reduction in acquisition time of multiparametric magnetic resonance (MR) imaging of the prostate. In particular, Dr Kuhl and colleagues investigated the diagnostic accuracy of a shortened biparametric MR imaging protocol composed by the sole evaluation of axial T2-weighted and diffusion-weighted imaging. The authors showed how this approach led to a similar diagnostic performance in the detection of prostatic lesions compared with the standard multiparametric MR imaging protocol. In the first letter, Dr Scialpi and colleagues (1) pointed out that the elimination of sagittal and coronal T2-weighted images could make it difficult to measure both prostate and lesion volume, as well as to perform targeted biopsy when using fusion systems that require these planes. Furthermore, Dr Scialpi and colleagues suggested that the sagittal plane is essential for the assessment of extraglandular disease. On the other hand, Drs Kaji and Inamura pointed out that, in the article by Dr Kuhl and colleagues, patients were considered having a positive index test result when they had a Prostate Imaging Reporting and Data System (PI-RADS) score of 3, 4, or 5 (2–3). In this setting, considering that dynamic contrast-enhanced (DCE) evaluation allows only for an upgrade of PI-RADS score from 3 to 4 (4), it is clear that its possible contribution to a correct diagnostic assessment is not significant. Our opinion, which is consistent with data available in the literature, is that biparametric MR imaging offers clear and significant advantages over standard multiparametric MR imaging, providing a similar diagnostic accuracy but leading to a significant reduction of acquisition time, which is directly related to both patient discomfort and costs (5). Future studies are strongly warranted to better identify and evaluate all possible strategies and combination of T2-weighted imaging and diffusion-weighted imaging, considering all advantages and disadvantages of their combination. However, in the transition from PI-RADS version 1 to PI-RADS version 2, the role of MR spectroscopy and DCE imaging was already reappraised and reduced, and at the time further concerns regarding the usefulness of DCE were raised (6). In light of the recently published articles on shortened biparametric MR imaging prostatic protocols (3,5,7), our opinion is that DCE should no longer be considered mandatory and its role further revised within a new and up-to-date version of PI-RADS.

Characterization of Adrenal Lesions on Unenhanced MRI Using Texture Analysis: A Machine-Learning Approach: MR Texture Analysis of Adrenal Lesions

Adrenal adenomas (AA) are the most common benign adrenal lesions, often characterized based on intralesional fat content as either lipid‐rich (LRA) or lipid‐poor (LPA). The differentiation of AA, particularly LPA, from nonadenoma adrenal lesions (NAL) may be challenging. Texture analysis (TA) can extract quantitative parameters from MR images. Machine learning is a technique for recognizing patterns that can be applied to medical images by identifying the best combination of TA features to create a predictive model for the diagnosis of interest.

Spectrum of lytic lesions of the skull: a pictorial essay

Lytic lesions of the skull include a wide range of diseases, ranging from benign conditions such as arachnoid granulations or vascular lacunae, to aggressive malignant lesions such as lymphomas or metastases. An early and correct characterisation of the nature of the lesion is, therefore, crucial, in order to achieve a fast and appropriate treatment option. In this review, we present the radiological appearance of the most frequent lytic lesions of the skull, describing findings from different imaging modalities (plain X-rays, CT and MRI), with particular attention to diagnostic clues and differential diagnoses.Teaching Points• Osteolytic skull lesions may be challenging to diagnose.• Association of different imaging techniques may aid image interpretation.• Clinical information and extensive knowledge of possible differential diagnoses is essential.• Some osteolytic tumours, although benign, may present as locally aggressive lesions.• Malignant lesions require accurate staging, followed by variable treatment approaches.

PSA-density does not improve bi-parametric prostate MR detection of prostate cancer in a biopsy naïve patient population

PURPOSE Bi-parametric prostate MR (bp-MR) is a valuable tool for detection and characterization of prostate cancer (PCa). Recent studies suggested that PSA-density (PSA-D) in combination with multi-parametric prostate MR as well as bp-MR may achieve a higher diagnostic accuracy than either alone. We aimed to evaluate the diagnostic performance of bp-MR, PSA-D and their combination in biopsy-naïve patients. METHODS AND MATERIALS We retrospectively analyzed 334 consecutive patients who underwent prostate MR on a 3T scanner. Only patients (n = 114) who underwent TRUS-biopsy within 30 days following MR with no previous prostate biopsies were considered. Our protocol included T2-weighted and DWI sequences. A Likert score based on PI-RADS v2 was used for bp-MR evaluation. Lesions were graded histopathologically using the ISUP score. We assessed three scenarios: detection of lesions independently of ISUP score (ISUP ≥ 1), detection of both intermediate and clinically significant lesions (ISUP ≥ 2) and detection of clinically significant lesions alone (ISUP ≥ 3). Predictive value of bp-MR and PSA-D was evaluated by ROC curves and logistic regression analysis. A p value < 0.05 was considered statistically significant. RESULTS In all evaluated scenarios, bp-MR showed a significantly higher predictive power (AUC = 0.87-0.95) compared to the performance of PSA-D (AUC = 0.73-0.79), while their combination (AUC = 0.91-0.95) showed no statistically significant improvement compared to bp-MR alone. CONCLUSION Our results confirm that bp-MR is a powerful tool in detection of clinically significant PCa. Contrary to findings in the recent literature, PSA-D does not appear to significantly improve its diagnostic performance.

Multidisciplinary Approach in the Management of Head and Neck Vascular Malformations

Purpose: Arteriovenous malformations (AVM) of the head and neck are rare anomalies, but often present with significant haemorrhage or cosmetic defects. The purpose of this study is to determine the effectiveness of embolization of each type of vascular malformation. Methods: A retrospective review was performed between January 2009 to June 2015 on 36 patients who were diagnosed vascular malformations in the head and neck regions and were referred to our department for transarterial or percutaneous embolization before the surgical approach. Results: All 26 AVM were embolized with a transarterial approach: 18 with Onyx, 8 with a combination of PVA and coils. All patients with an AVM had a single endovascular approach. All 10 venous-lymphatic malformations were treated with a percutaneous sclerotherapy with ethanol injection. Complete healing was obtained in 30 patients (83%). In 6 (17%) there was a recurrence with necessity of a retreatment, 4 at 6 months, 2 at 12 months. Conclusion: Transarterial embolization and percutaneous scleroterapy is a safe treatment for artero-venous malformations before the surgical treatment. A multidisciplinary approach is fundamental to reduce the bleeding risks, the time of the surgical intervention and favouring a lesser demolitive approach particularly in large vascular malformations. Surgical complications occurred in 6 patients (17%); all of them developed infections of the surgical wounds; 3 of these developed necrosis of the skin flap used for the reconstruction with subsequent dehiscence. No other complications including sepsis, hemorrhages, cranial nerve palsies or neuropathies occurred.

Cardiac Radionuclide Imaging After Coronary Artery Revascularization

In the last decades, advances in the therapeutic options for cardiovascular diseases, coupled with improvements in imaging technology contributed to the explosive growth in the number of cardiovascular imaging procedures performed, which also raised concern about overuse. The decision whether cardiac imaging is reasonable or not should be based on how the information gained will influence subsequent patient care and outcomes. Appropriate use criteria have been developed by the major scientific societies and the resulting documents aim to categorize specific clinical scenarios and to indicate whether an imaging test is reasonable to perform, or whether the test has uncertain or inappropriate indications. Imaging decisions based on these authoritative criteria provides assurance that the test is reasonable and the clinical benefits outweigh the potential risks. This review focuses on the value of cardiac radionuclide imaging after coronary artery revascularization, in particular in clinical subgroups of subjects for whom uncertainty still exist.

Prognostic Value of Stress Myocardial Perfusion Imaging in Asymptomatic Diabetic Patients

Although there has been a marked decline in mortality due to coronary artery disease (CAD) in the overall population in the past three decades, reducing CAD mortality in patients with diabetes has proven exceptionally difficult. Several epidemiological studies have shown that diabetes is associated with a marked increase in the risk of CAD. The symptoms are not a reliable means of identifying patients at higher risk considering that angina is threefold less common in diabetics than in nondiabetics. The increasing prevalence of diabetes and the associated high cardiac risk raised the question as to the need to develop approaches to identify the diabetic patients at the highest risk of CAD. Stress myocardial perfusion single-photon emission computed tomography has taken a central role in the diagnosis, evaluation, and management of CAD in diabetic patients. This review focuses on the prognostic value of cardiac radionuclide imaging in asymptomatic diabetic patients.