1,721,033 research outputs found
L’eterogeneità perfusionale: un biomarker prognostico per il cancro del polmone non a piccole cellule (NSCLC)
No full textL’introduzione in oncologia di nuove terapie, in particolare quelle a bersaglio molecolare, ha condotto a notevoli progressi terapeutici, determinando miglior controllo del tumore, selettività terapeutica, ridotta tossicità. Tuttavia la prognosi per i pazienti affetti da tumore polmonare non a piccole cellule (NSCLC) in stadio avanzato risulta tuttora molto severa. Sebbene il più importante fattore prognostico sia attualmente costituito dallo stadio del tumore, la sopravvivenza di pazienti affetti da NSCLC e appartenenti allo stesso stadio risulta ampiamente variabile. Per queste ragioni, è necessario identificare marcatori prognostici più efficaci che siano in grado di stabilire quali tumori saranno sensibili o resistenti alle terapie. Questo condurrebbe ad una migliore gestione e stratificazione dei pazienti affetti da NSCLC, con notevoli implicazioni nella scelta dei trattamenti. L’analisi dell’eterogeneità neoplastica nei pazienti NSCLC, caratterizzata attraverso l’analisi strutturale mediante Tomografia Computerizzata (TC), ha mostrato notevoli potenzialità nel predire l’aggressività di un tumore. Anche più promettente è l’analisi dell’eterogeneità funzionale in grado di mettere in luce non solo le anomalie strutturali ma anche le disomogeneità funzionali presenti all’interno di un tumore. Tra le tecniche di imaging funzionale, particolare rilievo sta assumendo la TC perfusionale (TCp), che permette l’identificazione di pattern vascolari anomali, consentendo una valutazione precoce della risposta alle terapie citostatiche. In questo lavoro retrospettivo, valutiamo se alcuni indicatori, calcolabili a partire dalle mappe di valori perfusionali ottenute tramite TCp, possano essere utilizzati come marcatori prognostici. I risultati rilevano una coppia di indicatori in grado di separare pazienti affetti da NSCLC con diversa aspettativa di sopravvivenza. Viene confermata la comune aspettativa che una maggiore eterogeneità correli con una maggiore aggressività, riflettendosi gravemente sulla sopravvivenza dei pazienti. Si può quindi concludere che la misura emodinamica dell’eterogeneità tumorale rappresenti un significativo e oggettivo fattore prognostico, con possibili ricadute cliniche della TCp
Multislice analysis of blood flow values in CT perfusion studies of lung cancer
No full textObjectives: Tumour heterogeneity represents a key issue in CT perfusion (CTp), where all studies are usually based on global mean or median values of perfusion maps, often computed on whole tumour. We sought to determine whether, and to what extent, such global values can be representative of tumour heterogeneity, with respect to single slices, and could be used for therapy assessment.
Materials and Methods: Twelve patients with one primary non-small cell lung cancer lesion were enrolled in this study, for a total amount of 26 CTp examinations and 118 slices. Mean and median blood flow (BF) values, calculated voxel-based, were computed on each slice and the whole tumour. To measure functional heterogeneity, entropy was calculated on BF values as well.
Results: Most of the slices were not represented by the global BF values computed on the whole tumour. In addition, there is a number of lesions having equivalent global BF values, but composed by slices having very different heterogeneity distributions, that is, entropy values.
Conclusions: Global mean/median BF values of the single slices separately should be considered for clinical assessment, only if interpreted through entropy computed on BF values. The numerical equivalence between global BF values of different lesions may correspond to different clinical status, thus inducing possible errors in choice of therapy when considering global value only
Automatic detection of misleading blood flow values in CT perfusion studies of lung cancer
No full textIn the oncology field, the anti-angiogenetic therapies aim at inhibiting tumour vascularization, that is the development of new capillary blood vessels in tumours, that allows them to grow and spread and, potentially, to metastasise. Computed Tomography perfusion (CTp) is a dynamic contrast-enhanced technique that has emerged in the last few years as a promising approach for earlier assessment of such therapies, and of tumour response, in general, since functional changes precede morphological
changes, that take more time to become evident. However several issues, such as patient motion and several types of artefacts, jeopardize quantitative measurements, this preventing CTp to be used in standard clinics. This paper presents an original automatic approach, based on the voxel-based analysis of the time-concentration curves (TCCs), that allows emphasizing those physiological structures, such as vessels, bronchi or artefacts, that could affect the final computation of blood flow perfusion values in CTp studies of lung cancer. The automatic exclusion of these misleading values represents a step towards a quantitative CTp, hence its routine use in clinics
Primary and secondary hyperparathyroidism: Findings on chest X-rays and high resolution CT
No full textHyperparathyroidism induces high level of serum calcium, with mobilization from bone. Consequence
of this process is the deposition in the soft tissue. In the lung deposition of calcium induces restrictive
changes with hypoxemia. Two different cases of hyperparathyroidism are shown in this report in which
high level of calcium has induced early and late parenchymal changes
DCE-CT in lung cancer: perfusion characterisation of adenocarcinoma and squamous carcinoma subtypes
No full textPurpose: To evaluate tumour baseline characteristics in blood flow (BF) values of two lung cancer subtypes, adenocarcinoma (AC) and squamous cell carcinoma (SCC). In addition, since literature shows discordant results, we also investigate possible motivations, so as to find out a clearer outcome.
Methods and Materials: 27 patients (age range 36-81 years) with primary NSCLC, subdivided into 20 AC and 7 SCC, were enrolled in this study and underwent a CT perfusion at the diagnosis stage. BF values were computed according to the maximum slope method and values undergoing high fitting errors were automatically removed. The one-tail Welch's t-test (p<0.001) was employed for statistical assessment.
Results: At baseline, mean BF values of AC group [81.4±30.1] result significantly greater than those of SCC subtype [59.6±31.7] (p<<10-5). Excluding unreliable BF values enforced the outcome. However, a few cases deviate from the mean value of the corresponding histological group. Two SCC lesions present a higher perfusion because of beam hardening artefacts coming from the pulmonary artery. Analogously, four AC cases show a lower perfusion, two of which are large and central lesions. The others, in the subpleural parenchyma, have a predominant pulmonary component underestimated by a delayed acquisition.
Conclusion: At diagnosis, AC histological type has a significantly greater perfusion than SCC one. This clear behaviour may be attenuated by lesion position, central or peripheral, pulmonary artery artefacts and not appropriate acquisition protocol. Although these findings are clear, they should be enforced by a larger dataset, being of relevant importance for treatment strategies
Automatic visual-like classification of lung tumour heterogeneity in DCE-CT sequences
No full textPurpose: Tumour heterogeneity is an important prognostic factor, as high intra-tumour heterogeneity showed to be associated with higher tumour grades. However, its assessment is still mostly accomplished subjectively through visual procedure. This work presents an automatic approach to classify the heterogeneity levels in lung tumour as performed through visual analysis.
Methods and Materials: 40 datasets referring to 13 patients (age range 36-81 years) with NSCLC, who underwent axial DCE-CT, were considered. Two 25-year experienced Readers chose the most representative slices in the DCE-CT sequences, outlined each lesion and its most significant regions. Then, each slice was assigned a class, according to a proper taxonomy for heterogeneity levels previously defined: homogeneous, macro-inhomogeneous (i.e., different homogeneities together), and micro-inhomogeneous. A statistical voxel-based index was devised to quantify the heterogeneity, then represented in colorimetric maps. The values were grouped into regions subsequently compared with those drawn by radiologists.
Results: Results for the three classes were computed in terms of specificity (SP) and sensitivity (SE). Our approach proved to be extremely specific, mostly for homogeneous (SE=77%, SP=93%) and macro-inhomogeneous (SE=75%, SP=90%) tissues. On the other hand, the most indefinite micro-inhomogeneous tissue also shows a high specificity (SE=86%, SP=87%).
Conclusion: The approach developed allows an automatic classification of heterogeneities, with a reduction of both intra- and inter-observer variability. This represents a novel approach acting as a second radiologist in the heterogeneity assessment, which could yield a great benefit for patient stratification and constitutes a valid tool to assist radiologists in daily clinical activities
Incidental lung nodules on CT examinations of the abdomen: prevalence and reporting rates in the PACS era.
No full textTo retrospectively evaluate prevalence, reporting rates and clinical implications of incidental pulmonary nodules detected in multidetector computed tomography (MDCT) abdominal studies.Abdominal MDCT studies of 243 consecutive patients, 94 of whom had a history of cancer, were evaluated. Lung bases included in the scan were reviewed on a PACS workstation with different window settings and post-processing techniques. Nodules were classified according to their density (calcified, solid noncalcified, non-solid, part-solid) and size (8mm). The study findings were compared with the corresponding radiologic reports. Previous of following CT studies, when available from the PACS, were also reviewed to evaluate changes in number and size of the detected nodules.An average of 8.2 cm of lung parenchyma was imaged in each patient. 213 noncalcified nodules (NCNs) were identified in 95 patients (39.1\%) but only 8 patients (8.4\%) had it mentioned in the final report. Comparison CT studies were available for 44 out of the 95 positive patients showing disappearance of the nodules in 2 cases, no interval change in 26 and progression in size and/or number in 16 patients, in whom a final diagnosis of metastasis or primary lung cancers was achieved.Radiologists tend to overlook lung portions on abdominal CT studies. Underreporting may affect patient care and have medico-legal implications since images are permanently stored in digital format on PACS and CD-ROMs. Management of the discovered nodules should be tailored to the clinical situation of the patient, and particular care should be reserved to patients with oncologic history
Primary hyperparathyroidism: imaging to pathology
No full text: The aim of this review is to describe the multimodal imaging (ultrasound, magnetic resonance, computed tomography, and nuclear medicine) of primary hyperparathyroidism and its correlation to the pathological findings. In the last decades, imaging science has progressed a great deal. Accurate preoperative localization of the involved glands is essential for surgical success
Prevalence of thoracolumbar vertebral fractures on multidetector CT: underreporting by radiologists.
No full textTo evaluate the prevalence of osteoporotic vertebral fractures in patients undergoing multidetector computed tomography (MDCT) of the chest and/or abdomen.323 consecutive patients (196 males, 127 females) with a mean age of 62.6 years (range 20-88) who had undergone chest and/or abdominal MDCT were evaluated. Sagittal reformats of the spine obtained from thin section datasets were reviewed by two radiologists and assessed for vertebral fractures. Morphometric analysis using electronic calipers was performed on vertebral bodies which appeared abnormal upon visual inspection. A vertebral body height loss of 15\% or more was considered a fracture and graded as mild (15-24\%), moderate (25-49\%) or severe (more than 50\%). Official radiology reports were reviewed and whether the vertebral fractures had been reported or not was noted.31 out of 323 patients (9.5\%) had at least 1 vertebral fracture and 7 of those patients had multiple fractures for a total of 41 fractures. Morphometric grading revealed 10 mild, 16 moderate and 15 severe fractures. Prevalence was higher in women (14.1\%) than men (6.6\%) and increased with patients age with a 17.1\% prevalence in post-menopausal women. Only 6 out 41 vertebral fractures (14.6\%) had been noted in the radiology final report while the remaining 35 (85.45) had not.although vertebral fractures represent frequent incidental findings on multidetector CT studies and may be easily identified on sagittal reformats, they are often underreported by radiologists, most likely because of unawareness of their clinical importance
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