Effects of different levels of CT iterative reconstruction on low-contrast detectability and radiation dose in patients of different sizes: an anthropomorphic phantom study.

PURPOSE: The purpose of this study was to verify the maintenance of low-contrast detectability at different CT dose reduction levels, in patients of different sizes, as a consequence of the application of iterative reconstruction at different strengths combined with tube current modulation. METHODS: Anthropomorphic abdominal phantoms of two sizes (small and large) were imaged at a fixed noise with iterative algorithm ASIR-V percentages in the range between 0 and 70% and corresponding dose reductions in the range of 0-83%. A total of 1400 images with and without liver low-contrast simulated lesions were evaluated by five radiologists, using the receiver operating characteristics (ROC) paradigm and evaluating the area under the ROC curve (AUC). The human observer results were then compared with AUC obtained with a channelized Hotelling observer (CHO). CNR values were also calculated. RESULTS: For the small phantom, the AUC values lie between 0.90 and 0.93 for human evaluations of images acquired without iterative reconstruction, with 30% ASIR-V and with 50% ASIR-V. The AUC decreased significantly to 0.81 (p = 0.0001) at 70% ASIR-V. The CHO results were in coherence with human observer scores. Also, similar results were observed for the large size phantom. CNR values were stable for the different ASIR-V percentages. CONCLUSIONS: The iterative algorithm maintained the low-contrast detectability up to a dose reduction of about 70%, following application of a 50% ASIR-V combined with automatic tube current modulation, regardless of the phantom size. At further dose reductions using greater iterative percentages, a significant decrease in detectability was observed.

Angiographic control versus ischaemia-driven management of patients undergoing percutaneous revascularisation of the unprotected left main coronary artery with second-generation drug-eluting stents: rationale and design of the PULSE trial.

BACKGROUND: The role of planned angiographic control (PAC) over a conservative management driven by symptoms and ischaemia following percutaneous coronary intervention (PCI) of the unprotected left main (ULM) with second-generation drug-eluting stents remains controversial. PAC may timely detect intrastent restenosis, but it is still unclear if this translated into improved prognosis. METHODS AND ANALYSIS: PULSE is a prospective, multicentre, open-label, randomised controlled trial. Consecutive patients treated with PCI on ULM will be included, and after the index revascularisation patients will be randomised to PAC strategy performed with CT coronary after 6 months versus a conservative symptoms and ischaemia-driven follow-up management. Follow-up will be for at least 18 months from randomisation. Major adverse cardiovascular events at 18 months (a composite endpoint including death, cardiovascular death, myocardial infarction (MI) (excluding periprocedural MI), unstable angina, stent thrombosis) will be the primary efficacy outcome. Secondary outcomes will include any unplanned target lesion revascularisation (TLR) and TLR driven by PAC. Safety endpoints embrace worsening of renal failure and bleeding events. A sample size of 550 patients (275 per group) is required to have a 80% chance of detecting, as significant at the 5% level, a 7.5% relative reduction in the primary outcome. TRIAL REGISTRATION NUMBER: NCT04144881.

Lenvatinib in Advanced Radioiodine-refractory Thyroid Cancer: A Snapshot of Real-life Clinical Practice.

BACKGROUND: We retrospectively analyzed the efficacy and safety of lenvatinib in 12 patients with advanced radioiodine-refractory thyroid cancer in the setting of daily clinical practice. PATIENTS AND METHODS: The starting daily dose of lenvatinib was 24 mg, tapered in the case of adverse events. Disease status was periodically evaluated by a single radiologist and safety assessment was regularly performed. RESULTS: After a median follow-up of 13.3 months, 6- and 12-month progression-free survival rates were 63.6% and 54.6%, respectively. Overall survival at 6 and 12 months was 83.3% and 75.0%. Partial response was observed in five patients, while two showed stable disease as their best response. Conversely, progressive disease at first radiological assessment was detected in four patients. All patients experienced at least one adverse event, including systemic and gastrointestinal toxicity, high blood pressure and hand-foot syndrome. In order to manage toxicity, transient drug interruption and dose reduction were required in 10 and 9 cases, respectively. CONCLUSION: Our data confirm lenvatinib efficacy in patients with advanced thyroid cancer, despite an important toxic profile.

Adaptive Statistical Iterative Reconstruction-V Versus Adaptive Statistical Iterative Reconstruction: Impact on Dose Reduction and Image Quality in Body Computed Tomography.

OBJECTIVE: The aim of this study was to evaluate the impact on dose reduction and image quality of the new iterative reconstruction technique: adaptive statistical iterative reconstruction (ASIR-V). METHODS: Fifty consecutive oncologic patients acted as case controls undergoing during their follow-up a computed tomography scan both with ASIR and ASIR-V. Each study was analyzed in a double-blinded fashion by 2 radiologists. Both quantitative and qualitative analyses of image quality were conducted. RESULTS: Computed tomography scanner radiation output was 38% (29%-45%) lower (P < 0.0001) for the ASIR-V examinations than for the ASIR ones. The quantitative image noise was significantly lower (P < 0.0001) for ASIR-V. Adaptive statistical iterative reconstruction-V had a higher performance for the subjective image noise (P = 0.01 for 5 mm and P = 0.009 for 1.25 mm), the other parameters (image sharpness, diagnostic acceptability, and overall image quality) being similar (P > 0.05). CONCLUSIONS: Adaptive statistical iterative reconstruction-V is a new iterative reconstruction technique that has the potential to provide image quality equal to or greater than ASIR, with a dose reduction around 40%.

Tyrosine kinase inhibitors rechallenge in solid tumors: a review of literature and a case description with lenvatinib in thyroid cancer.

INTRODUCTION: In the last decade tyrosine kinase inhibitors (TKIs) have been employed for a wide range of hematological and solid tumors and today they represent a valid therapeutic option for different neoplasms. Among them, both sorafenib and lenvatinib were approved for the treatment of radioactive iodine (RAI) refractory differentiated thyroid carcinoma (DTC). Unfortunately, in some cases the efficacy of TKIs is limited by the onset of drug resistance after the initial response. Areas covered: We report the case of a patient with a RAI refractory advanced DTC, treated with lenvatinib after surgery, multiple RAI administrations, traditional chemotherapy, and sorafenib. During treatment with lenvatinib, a noticeable response was detected by sequential computed tomography scans but, after 27 months, tumor progression became evident and led to lenvatinib interruption. In absence of any active treatment, a further disease progression was documented, and lenvatinib was re-administered obtaining a new objective response. Starting from this case report, we review available reports about the rechallenge with TKIs in solid tumors, discussing the possible mechanisms underlying the efficacy of this approach. Expert commentary: Rechallenge with TKIs in solid tumors could be a therapeutic option in subjects with advanced and metastatic DTC who experience a progressive disease after initial response to lenvatinib.

When size matters: changing opinion in the management of pleural space-the rise of small-bore pleural catheters.

Tube thoracostomy is usually the first step to treat several thoracic/pleural conditions such as pneumothorax, pleural effusions, haemothorax, haemo-pneumothorax and empyema. Today, a wide range of drains is available, ranging from small to large bore ones. Indications for an appropriate selection remains yet matter of debate, especially regarding the use of small bore catheters. Through this paper, we aimed to retrace the improvements of drains through the years and to review the current clinical indications for chest drain placement in pleural/thoracic diseases, comparing the effectiveness of small-bore drains vs. large-bore ones.

Extrahepatic aneurysm of the portal venous system and portal hypertension.

Portal venous aneurysm (PVA) is a rare condition characterized by dilatation of the portal venous system. PVA manifestation of symptoms is varied and depends on the aneurysm size, location and related-complications, such as thrombosis. While the majority of reported cases of PVA are attributed to portal hypertension, very little is known about the condition's pathophysiology and clinical management remains a challenge. Here, we describe a 67-year-old woman who presented with complaint of dyspepsia and without a significant medical history, for whom PVA was incidentally diagnosed. The initial upper abdominal ultrasound revealed marked dilatation of the main portal vein, and subsequent contrast-enhanced computed tomography with angiography revealed a large aneurysm arising from the extrahepatic troncus portion of the portal vein, as well as gastroesophageal varices. A conservative approach using beta-blocker therapy was chosen. The patient was followed-up for 60 mo, during which time the asymptomatic status was unaltered and the PVA remained stable.

Italian multicenter, prospective study to evaluate the negative predictive value of 16- and 64-slice MDCT imaging in patients scheduled for coronary angiography (NIMISCAD-Non Invasive Multicenter Italian Study for Coronary Artery Disease).

This was a prospective, multicenter study designed to evaluate the utility of MDCT in the diagnosis of coronary artery disease (CAD) in patients scheduled for elective coronary angiography (CA) using different MDCT systems from different manufacturers. Twenty national sites prospectively enrolled 367 patients between July 2004 and June 2006. Computed tomography (CT) was performed using a standardized/optimized scan protocol for each type of MDCT system (> or =16 slices) and compared with quantitative CA performed within 2 weeks of MDCT. A total of 284 patients (81%) were studied by 16-slice MDCT systems, while 66 patients (19%) by 64-slice MDCT scanners. The primary analysis was on-site/off-site evaluation of the negative predictive value (NPV) on a per-patient basis. Secondary analyses included on-site evaluation on a per-artery and per-segment basis. On-site evaluation included 327 patients (CAD prevalence 58%). NPV, positive predictive value (PPV), sensitivity, specificity, and diagnostic accuracy (DA) were 0.91 (95% CI 0.85-0.95), 0.91 (95% CI 0.86-0.95), 0.94 (95% CI 0.89-0.97), 0.88 (95% CI 0.81-0.93), and 0.91 (95% CI 0.88-0.94), respectively. Off-site analysis included 295 patients (CAD prevalence 56%). NPV, PPV, sensitivity, specificity, and DA were 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), and 0.82 (95% CI 0.77-0.86), respectively. The results of this study demonstrate the utility of MDCT in excluding significant CAD even when conducted by centers with varying degrees of expertise and using different MDCT machines.

Vascular anatomy of the rectal stump after total mesorectal excision.

PURPOSE: For many years, poor vascularization of the short rectal stump has been considered the main cause of leakage. The purpose of this study was to evaluate the vascularization of the rectal stump after total mesorectal excision. METHODS: We studied the iliac vascularization on 28 volunteers with healthy rectum to have an anatomic basis. Then, we studied the vascularization of the rectal stumps after total mesorectal excision by using angio computed tomography at seven and three months after operating on 22 patients; we validated this technique by studying the vascularization using angio computed tomography in 18 rectal specimens from cadavers. RESULTS: Both in healthy rectums and in rectal stumps after total mesorectal excision, there is good vascularization sustained by middle and inferior rectal arteries. The former is more important and frequent as described in previous literature. CONCLUSIONS: The vascularization of the short rectal stump is generally well represented even after total mesorectal excision.

[Patient dose evaluation and optimization of uropoietic multiphasic multislice CT examination].

PURPOSE: The aim of this study was to optimize acquisition data during multislice multiphasic CT examination of the renal excretory system in order to reduce patient effective dose without deterioration of the imaging quality. MATERIALS AND METHODS: With the aid of two dedicated software programmes we evaluated the patient effective dose during both multislice multiphasic CT examination of the renal excretory system and excretory urography. With the CT acquisition protocol, images of a test object (Helical CT phantom, CIRS) were examined by two expert radiologists to assess the number of visible inserted test images. Other scans of the test object were then obtained utilizing decreased tube current intensity; among these that with minor information loss was identified. Patient effective dose was measured utilizing correspondent acquisition data. RESULTS: Patient effective dose during multiphasic multislice CT examination before optimization (280 mA tube current intensity) was 22.9 mSv for males and 31.1 mSv for females; after optimization it was 19.6 mSv and 26.7 mSv, respectively, with a 14% decrease. Patient effective dose during CT direct phase before optimization was 8.9 mSv for males and 12.8 mSv for females, after optimization 7.6 mSv and 11 mSv with a 15% decrease. The absorbed dose for males is lower because the females gonads are completely included in the primary CT beam, whereas the testicles are hit by diffuse radiation only. DISCUSSION AND CONCLUSIONS: During CT direct phase the patient absorbed dose is 1.45 for males and 1.9 for females (1.2 and 1.6 respectively after optimization) higher than that absorbed during intravenous pyelography; the absorbed dose of a complete multiphasic CT examination is 3.7 for males and 4.6 for females (3.2 and 3.9 respectively after optimization) higher than that absorbed during intravenous pyelography. Such dosimetric data may be justified by diagnostic advantages in stone assessment, especially in males, and by the fact that multislice CT may unify different diagnostic tools such as intravenous pyelography, axial CT and angiography, thereby simplifying the entire diagnostic protocol. As far as exposure is concerned radiologists should follow the optimizing principle referred to each clinical query, bearing in mind that diagnostic accuracy is more important than the simple iconographic aspect.

Vasculitis mimicking bacterial endocarditis.

Fever of unknown origin is one of the most intriguing issues in clinical practice. One of the most feared diagnoses, especially in patients with known valvular disease, is endocarditis. The differential diagnosis of fever is often complicated by the clinical-pathological overlap between the systemic inflammatory response in different types of pathologies such as infectious, autoimmune or neoplastic disorders. We report a case of a patient presenting with fever, cutaneous nodules and malaise, with a known mitral valve prolapse and moderate regurgitation, in which the diagnosis of Wegener's granulomatosis was finally made.