imaging biomarkers in upper gastrointestinal cancers

In parallel with the increasingly widespread availability of high performance imaging platforms and recent progresses in pathobiological characterisation and treatment of gastrointestinal malignancies, imaging biomarkers have become a major research topic due to their potential to provide additional quantitative information to conventional imaging modalities that can improve accuracy at staging and follow-up, predict outcome, and guide treatment planning in an individualised manner. The aim of this review is to briefly examine the status of current knowledge about imaging biomarkers in the field of upper gastrointestinal cancers, highlighting their potential applications and future perspectives in patient management from diagnosis onwards

Radiomics and Magnetic Resonance Imaging of Rectal Cancer: From Engineering to Clinical Practice

While cross-sectional imaging has seen continuous progress and plays an undiscussedpivotal role in the diagnostic management and treatment planning of patients with rectal cancer, alargely unmet need remains for improved staging accuracy, assessment of treatment response andprediction of individual patient outcome. Moreover, the increasing availability of target therapies hascalled for developing reliable diagnostic tools for identifying potential responders and optimizingoverall treatment strategy on a personalized basis. Radiomics has emerged as a promising, still fullyevolving research topic, which could harness the power of modern computer technology to generatequantitative information from imaging datasets based on advanced data-driven biomathematicalmodels, potentially providing an added value to conventional imaging for improved patient manage-ment. The present study aimed to illustrate the contribution that current radiomics methods appliedto magnetic resonance imaging can offer to managing patients with rectal cancer

Comparative Multicentric Evaluation of Inter-Observer Variability in Manual and Automatic Segmentation of Neuroblastic Tumors in Magnetic Resonance Images

[EN] Simple Summary Tumor segmentation is a key step in oncologic imaging processing and is a time-consuming process usually performed manually by radiologists. To facilitate it, there is growing interest in applying deep-learning segmentation algorithms. Thus, we explore the variability between two observers performing manual segmentation and use the state-of-the-art deep learning architecture nnU-Net to develop a model to detect and segment neuroblastic tumors on MR images. We were able to show that the variability between nnU-Net and manual segmentation is similar to the inter-observer variability in manual segmentation. Furthermore, we compared the time needed to manually segment the tumors from scratch with the time required for the automatic model to segment the same cases, with posterior human validation with manual adjustment when needed. Tumor segmentation is one of the key steps in imaging processing. The goals of this study were to assess the inter-observer variability in manual segmentation of neuroblastic tumors and to analyze whether the state-of-the-art deep learning architecture nnU-Net can provide a robust solution to detect and segment tumors on MR images. A retrospective multicenter study of 132 patients with neuroblastic tumors was performed. Dice Similarity Coefficient (DSC) and Area Under the Receiver Operating Characteristic Curve (AUC ROC) were used to compare segmentation sets. Two more metrics were elaborated to understand the direction of the errors: the modified version of False Positive (FPRm) and False Negative (FNR) rates. Two radiologists manually segmented 46 tumors and a comparative study was performed. nnU-Net was trained-tuned with 106 cases divided into five balanced folds to perform cross-validation. The five resulting models were used as an ensemble solution to measure training (n = 106) and validation (n = 26) performance, independently. The time needed by the model to automatically segment 20 cases was compared to the time required for manual segmentation. The median DSC for manual segmentation sets was 0.969 (+/- 0.032 IQR). The median DSC for the automatic tool was 0.965 (+/- 0.018 IQR). The automatic segmentation model achieved a better performance regarding the FPRm. MR images segmentation variability is similar between radiologists and nnU-Net. Time leverage when using the automatic model with posterior visual validation and manual adjustment corresponds to 92.8%.This study was funded by PRIMAGE (PRedictive In silico Multiscale Analytics to support cancer personalized diaGnosis and prognosis, empowered by imaging biomarkers), a Horizon 2020 | RIA project (Topic SC1-DTH-07-2018), grant agreement no: 826494.Veiga-Canuto, D.; Cerdà-Alberich, L.; Sangüesa Nebot, C.; Martínez De Las Heras, B.; Pötschger, U.; Gabelloni, M.; Carot Sierra, JM.... (2022). Comparative Multicentric Evaluation of Inter-Observer Variability in Manual and Automatic Segmentation of Neuroblastic Tumors in Magnetic Resonance Images. Cancers. 14(15):1-15. https://doi.org/10.3390/cancers14153648115141

One-stop 64-row CT coronary angiography in patients candidate to transcatheter aortic valve implantation (TAVI): can it replace invasive coronary angiography?

PURPOSE To assess feasibility and diagnostic accuracy of one-stop, low iodine 64-row CT coronary angiography (CTCA) performed with the same imaging protocol used for treatment planning in detecting significant coronary artery disease (CAD) in patients with severe aortic stenosis candidate to TAVI. MATERIALS AND METHODS From January 2017 to June 2018, 95 TAVI candidates underwent multidetector CT angiography (MDCTA) for TAVI planning on a high definition 64-row CT scanner. Following an ECG-ungated thoraco-abdominal MDCTA acquisition for the evaluation of potential vascular access routes, a single retrospectively ECG-gated CTCA acquisition was performed for annular sizing and to rule out significant (≥50% lumen narrowing) coronary stenosis using a low iodine concentration (270mgI/mL) contrast injection protocol. CTCA was considered positive in presence of inconclusive findings or of at least one significant stenosis of the left main artery (LMA) and/or the proximal segment of the left anterior descending (LAD), circumflex (CX) or right coronary (RCA) arteries. RESULTS Per-patient sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of CTCA versus ICA as gold standard were 100%, 60%, 65.2% and 100%, respectively. On a per-vessel basis, sensitivity and NPV were 100% for the LMA and the proximal segments of LAD, CX and RCA, whereas specificity ranged from 57.7% for proximal RCA to 79.3% for proximal LAD. Agatston score showed a significant negative correlation with image quality in patients who underwent both CTCA and ICA (rs=-0.6879, p<0.0001), but not in those who forwent ICA (rs=-0.1936, p=0.2186) due to negative pre-procedural CTCA findings. Iodine load for CTCA acquisitions was 9.4-13.5 gI. No complications occurred immediately after CTCA. CONCLUSIONS One-stop high definition 64-row CTCA with a low iodine protocol is feasible for pre-procedural coronary assessment in TAVI candidates and could reliably serve as a gatekeeper to ICA owing to its high effectiveness in detecting significant CAD

TC coronarica con ECG-gating prospettico e ricostruzione iterativa delle immagini: valutazione della dose radiante e della qualita' diagnostica.

Con l’introduzione della TC multistrato si è assistito a un forte aumento dell’utilizzo della TC in radiodiagnostica, ampliando anche la varietà delle sue applicazioni cliniche, come la coronaro-TC e la TC cardiaca. Questo ha portato ad un notevole incremento della dose fornita alla popolazione e alla conseguente ricerca di tecniche di riduzione di dose. L’utilizzo della cardiosincronizzazione mediante ECG-gating prospettico o retrospettivo ha permesso di ottenere immagini di elevata qualità con dosi radianti assai contenute. Lo scopo di questa tesi è valutare la dose radiante e la qualità dell’immagine in esami di coronaro-TC ottenuti mediante scanner TC a 128 strati ed ECG-gating prospettico rispetto a scanner TC 64 strati ed ECG-gating retrospettivo. Cinquantasei pazienti sono stati sottoposti a coronaro-TC: ventinove utilizzando TC a 64 strati ed ECG-gating retrospettivo, ventisette con TC a 128 strati ed ECG-gating prospettico. Il secondo gruppo ha mostrato una notevole riduzione della dose e una miglior qualità delle immagini

Imaging of Adverse Events Related to Checkpoint Inhibitor Therapy

Immunotherapy with checkpoint inhibitors (ICIs) is becoming standard of practice for an increasing number of cancer types. ICIs enhance T-cell action against the cancer cells. By unbalancing the immune system ICIs may cause dysimmune toxicities, a series of disorders broadly defined immune-related adverse events (irAEs). IrAEs may affect any organ or apparatus and most frequently involve skin, colon, endocrine organs, liver, and lungs. Early identification and appropriate treatment of irAEs can improve patient outcome. The paper aims at reviewing mechanisms of the occurrence of irAEs, the importance of a proper diagnosis and the main pillars of therapy. To provide effective guidance to the comprehension of major irAEs imaging findings will be reviewed

Pulmonary sequestration: What the radiologist should know

Pulmonary sequestration consists of a nonfunctioning mass of lung tissue, either sharing the pleural envelope of the normal lung (intralobar) or with its own pleura (extralobar), lacking normal communication with the tracheobronchial tree and receiving its arterial supply by one or more systemic vessels. It is the second most common congenital lung anomaly according to pediatric case series, but its real prevalence is likely to be underestimated, and imaging plays a key role in the diagnosis and treatment management of the condition and its potential complications. We will give a brief overview of the pathophysiology, clinical presentation and imaging findings of intra- and extralobar pulmonary sequestration, with particular reference to multidetector computed tomography as part of a powerful and streamlined diagnostic approach

An unusual case of intrarenal coiled and ruptured guidewire

Objective. To the best of our knowledge there are only 3 reports of fractured guidewires inside the pelvicalyceal system, successfully removed with endourology techniques, and this is the first one presenting a tightly coiled intraparenchymal section. Material and methods: A 59-year-old woman was hospitalized for surgical treatment of a right kidney of reduced size. Past history revealed pyelolithotomy for a staghorn stone 14 months earlier at another Institution with subsequent ureteral obstruction, one failed attempt at ureteral double-J catheter insertion and one failed attempt at percutaneous nephrostomy placement 5 months postoperatively. Another nephrostomy was placed, but left indwelling briefly. CT scan demonstrated a small-size kidney with residual stone fragments and presence of a “device” in the lower pole. The tapered distal extremity of an hydrophilic guidewire, with a tightly coiled central section wedged in the renal tissue was found inside the nephrectomy specimen. Results: While the Radiologist who read the CT scan hypothesized that the “device” was a fragment of double-J ureteral stent or nephrostomy catheter, it consisted of the hydrophilic extremity of a guidewire, broken during a previous attempt at nephostomy placement. Perirenal fibrosis and inappropriate angle between the needle and the lower calyx are the likely causes of guidewire coiling during its advancement and subsequent rupture during withdrawal. Conclusions. Urologists must be aware that, although percutaneous nephrostomy has a very high technical success rate, unusual complications like guidewire fracture may occur, and that modern imaging techniques can provide an accurate picture of this condition

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. Keywords: Kommerell’s diverticulum, Aberrant subclavian artery, Thrombosis, Multidetector computed tomography, Color doppler ultrasound, Non-small cell lung carcinom

Cardiac Computed Tomography Perfusion: Contrast Agents, Challenges and Emerging Methodologies from Preclinical Research to the Clinics

Computed Tomography (CT) has long been regarded as a purely anatomical imaging modality. Recent advances on CT technology and Contrast Agents (CA) in both clinical and preclinical cardiac imaging offer opportunities for the use of CT in functional imaging. Combined with modern ECG-gating techniques, functional CT has now become a reality allowing a comprehensive evaluation of myocardial global and regional function, perfusion and coronary angiography. This article aims at reviewing the current status of cardiac CT perfusion and micro-CT perfusion with established and experimental scanners and contrast agents, from clinical practice to the experimental domain of investigations based on animal models of heart diseases