Theoretical Compartment Modeling of DCE-MRI Data Based on the Transport across Physiological Barriers in the Brain

Neurological disorders represent major causes of lost years of healthy life and mortality worldwide. Development of their quantitative interdisciplinary in vivo evaluation is required. Compartment modeling (CM) of brain data acquired in vivo using magnetic resonance imaging techniques with clinically available contrast agents can be performed to quantitatively assess brain perfusion. Transport of 1H spins in water molecules across physiological compartmental brain barriers in three different pools was mathematically modeled and theoretically evaluated in this paper and the corresponding theoretical compartment modeling of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) data was analyzed. The pools considered were blood, tissue, and cerebrospinal fluid (CSF). The blood and CSF data were mathematically modeled assuming continuous flow of the 1H spins in these pools. Tissue data was modeled using three CMs. Results in this paper show that transport across physiological brain barriers such as the blood to brain barrier, the extracellular space to the intracellular space barrier, or the blood to CSF barrier can be evaluated quantitatively. Statistical evaluations of this quantitative information may be performed to assess tissue perfusion, barriers' integrity, and CSF flow in vivo in the normal or disease-affected brain or to assess response to therapy

Diagnosticul imagistic al carcinomatozei peritoneale

Clinica de diagnostic imagistic Hiperdia, Cluj-Napoca, UMF Iuliu Haţieganu, Cluj-NapocaCarcinomatoza peritoneală este una dintre principalele cauze de nerezecabilitate a formaţiunilor tumorale abdominale și pelviene. Ea este frecvent nediagnosticată imagistic și este descoperită doar în cursul intervenţiei chirurgicale. Obiectivul acestei prezentări este de a informa privitor la modul în care ecografia și tomografia computerizată pot contribui la diagnosticul carcinomatozei peritoneale și de a avertiza medicii-radiologi asupra unor posibile aspecte particulare ale carcinomatozei peritoneale care, fiind interpretate incorect, pot duce la diagnostice fals negative. Locurile în care descoperim cel mai frecvent noduli de carcinomatoză peritoneală sunt fundul de sac Douglas (50%), joncţiunea ileocecală (40%), mezosigma (20%). Coalescenţa mai multor depozite metastatice duce la o reacţie desmoplastică, ce este mai ușor de vizualizat imagistic și este important să fie interpretată în context clinic. Invazia grăsimii mezenterice produce un aspect „infiltrat” al acesteia (la TC) și o creștere a ecogenităţii sale (ecografic). Prezenţa lichidului de ascită, cu precădere în anumite localizări, este un semn indirect ce poate sugera existenţa carcinomatozei peritoneale. Lucrarea își propune să descrie principalele semne de carcinomatoză peritoneală în ecografie (optimizată prin administrarea produsului de contrast) și TC

Ecografie cu produs de contrast, tomografie computerizată şi imagistică prin rezonanţă magnetică în diagnosticul formaţiunilor chistice de pancreas

Clinica de diagnostic imagistic Hiperdia, Cluj-Napoca, UMF Iuliu Haţieganu, Cluj-NapocaManagementul terapeutic al leziunilor chistice ale pancreasului depinde de caracterizarea şi diagnosticul lor imagistic. Leziunile chistice de pancreas se împart în pseudochisturi şi tumori chistice de pancreas. Diagnosticul diferenţial între aceste două tipuri de leziuni este foarte important şi nu întotdeauna uşor atunci când contextul clinic nu este clar. Obiectivul acestei lucrări este de a demonstra cât de fiabile sunt tehnicile imagistice în diagnosticul pozitiv şi diferenţial al formaţiunilor chistice de pancreas şi care sunt atuurile şi limitele fiecărei tehnici imagistice în diagnosticul acestor formaţiuni. Pentru pseudochisturi trebuie să precizăm dimensiunile lor, omogenitatea/inomogenitatea conţinutului lor, cât de bine sunt ele delimitate, precum şi, dacă este posibil, existenţa unei eventuale comunicări între pseudochist şi ductul Wirsung. Cele mai frecvente tumori chistice de pancreas sunt chistadenoamele seroase şi mucinoase şi leziunile de tip IPMT. Rolul imagisticii este de a stabili dacă aceste tumori reprezintă indicaţie pentru intervenţie chirurgicală imediată sau se recomandă urmărirea lor. În cazul tumorilor cu un caracter imagistic evident de malignitate (cum ar fi chistadenocarcinoamele mucinoase), trebuie să precizăm rezecabilitatea/ nerezecabilitatea lor, în funcţie de existenţa invaziilor vasculare şi a determinărilor secundare la distanţă

Bilateral orbital lymphoma: A diagnostic odyssey through surreal clinical and imaging features plus therapeutic implications

The paper aim was to present a case of bilateral, advanced, orbital lymphoma diagnosed in a middle aged man who was admitted in a clinical condition which almost defied reality. The entire orbito-facial region was replaced by massive ulcero-necrotic masses which completely distorted the normal anatomy, giving an alien-like resemblance of an otherwise ordinary man. The patient was submitted to several imaging examinations (head and whole body computer tomography, head MRI, laterocervical ultrasound and elastography) and surgical biopsy. The final diagnosis was stage IVB diffuse large B-cell lymphoma (DLBCL). Currently the patient is undergoing chemotherapy with astonishing response (clinically visible tumoral shrinkage).The differential diagnosis of orbital masses may be extensive, starting from inflammatory conditions, such as cellulitis, pseudotumor, sarcoidosis and finishing with metastases from lung, renal or breast cancers. However, considering the substantial tumor volume in this case and imaging aspects, lymphomatous origin was the first diagnostic verified and ultimately confirmed.The peculiarities of the case do not reside in the final diagnosis, for DLBCL is the most common form of non-Hodgkin lymphoma in middle aged men, but its debut or spread to orbits is rare, usually unilateral and diagnosed in less advanced stage

Diffusion-Weighted Magnetic Resonance Imaging as a Noninvasive Parameter for Differentiating Benign and Malignant Intraperitoneal Collections

Background and Objective: The imaging differentiation of benign from malignant intraperitoneal collections (IPCs) relies on the tumoral morphological modifications of the peritoneum, which are not always advocating for malignancy. We aimed to assess ascitic fluid with the apparent diffusion coefficient (ADC) to determine non-invasive, stand-alone, differentiation criteria for benign and malignant intraperitoneal effusions. Materials and Methods: Sixty-one patients with known IPCs who underwent magnetic resonance examinations for reasons such as tumor staging, undetermined abdominal mass and disease follow up were retrospectively included in this study. All subjects had a final diagnosis of the fluid based on pathological examinations, which were divided into benign (n = 37) and malignant (n = 24) IPCs groups. ADC values were measured separately by two radiologists, and the average values were used for comparing the two groups by consuming the independent samples t-test. The receiver operating characteristic analysis was performed to test the ADC values’ diagnostic ability to distinguish malignant from benign collections. Results: The differentiation between benign and malignant IPCs based on ADC values was statistically significant (p = 0.0034). The mean ADC values were higher for the benign (3.543 × 10−3 mm2/s) than for the malignant group (3.057 × 10−3 mm2/s). The optimum ADC cutoff point for the diagnosis of malignant ascites was <3.241 × 10−3 mm2/s, with a sensitivity of 77.78% and a specificity of 80%. Conclusions: ADC represents a noninvasive and reproducible imaging parameter that may help to assess intraperitoneal collections. Although successful in distinguishing malignant from benign IPCs, further research must be conducted in order to certify if the difference in ADC values is a consequence of the physical characteristics of the ascitic fluids or their appurtenance to a certain histopathological group

Rheumatoid Arthritis and CLOVES Syndrome: A Tricky Diagnosis

The PI3K/AKT/mTOR signaling pathway is significantly activated in rheumatoid arthritis. In addition, somatic activating mutations of the PI3K/AKT/mTOR pathway may result in PIK3CA-related overgrowth spectrum diseases, including CLOVES (Congenital Lipomatous Overgrowth, Vascular malformation, Epidermal nevi, Skeletal abnormalities/Scoliosis) syndrome. We describe the case of a young female patient, with anti-citrullinated peptide antibodies-positive rheumatoid arthritis, referred for persistent finger pain and stiffness. Examination revealed discrete macrodactyly involving two fingers, scoliosis, asymmetrical calves, venectasias, a shoulder nevus and triangular feet with a “sandal gap” between two toes. These mild dysmorphic features with early-onset and the history of surgeries for thoracic lipoma and venous malformation were strongly suggestive of CLOVES syndrome. Confirmatory mutation analysis was not performed, as blood or saliva testing is not contributive for tissue-specific localized effects in the PIK3CA-related overgrowth spectrum. Nevertheless, lack of detection of a PIK3CA mutation does not exclude the diagnosis in patients fulfilling clinical criteria. Due to the patient’s wish to plan a pregnancy, therapy consisted in sulfasalazine and hydroxychloroquine, along with orthotic correction of leg length discrepancy. Overgrowth syndromes and arthritis may share common pathways. Mild macrodactyly should be differentiated from dactylitis. Diagnosing patients with minimal dysmorphic features within the PI3K-related overgrowth spectrum may help design better care strategies, in the quest for personalized medicine

Quantitative MRI of Pancreatic Cystic Lesions: A New Diagnostic Approach

The commonly used magnetic resonance (MRI) criteria can be insufficient for discriminating mucinous from non-mucinous pancreatic cystic lesions (PCLs). The histological differences between PCLs’ fluid composition may be reflected in MRI images, but cannot be assessed by visual evaluation alone. We investigate whether additional MRI quantitative parameters such as signal intensity measurements (SIMs) and radiomics texture analysis (TA) can aid the differentiation between mucinous and non-mucinous PCLs. Fifty-nine PCLs (mucinous, n = 24; non-mucinous, n = 35) are retrospectively included. The SIMs were performed by two radiologists on T2 and diffusion-weighted images (T2WI and DWI) and apparent diffusion coefficient (ADC) maps. A total of 550 radiomic features were extracted from the T2WI and ADC maps of every lesion. The SIMs and TA features were compared between entities using univariate, receiver-operating, and multivariate analysis. The SIM analysis showed no statistically significant differences between the two groups (p = 0.69, 0.21–0.43, and 0.98 for T2, DWI, and ADC, respectively). Mucinous and non-mucinous PLCs were successfully discriminated by both T2-based (83.2–100% sensitivity and 69.3–96.2% specificity) and ADC-based (40–85% sensitivity and 60–96.67% specificity) radiomic features. SIMs cannot reliably discriminate between PCLs. Radiomics have the potential to augment the common MRI diagnosis of PLCs by providing quantitative and reproducible imaging features, but validation is required by further studies

Differentiation of Endometriomas from Ovarian Hemorrhagic Cysts at Magnetic Resonance: The Role of Texture Analysis

Background and Objectives: To assess ovarian cysts with texture analysis (TA) in magnetic resonance (MRI) images for establishing a differentiation criterion for endometriomas and functional hemorrhagic cysts (HCs) that could potentially outperform their classic MRI diagnostic features. Materials and Methods: Forty-three patients with known ovarian cysts who underwent MRI were retrospectively included (endometriomas, n = 29; HCs, n = 14). TA was performed using dedicated software based on T2-weighted images, by incorporating the whole lesions in a three-dimensional region of interest. The most discriminative texture features were highlighted by three selection methods (Fisher, probability of classification error and average correlation coefficients, and mutual information). The absolute values of these parameters were compared through univariate, multivariate, and receiver operating characteristic analyses. The ability of the two classic diagnostic signs (“T2 shading” and “T2 dark spots”) to diagnose endometriomas was assessed by quantifying their sensitivity (Se) and specificity (Sp), following their conventional assessment on T1-and T2-weighted images by two radiologists. Results: The diagnostic power of the one texture parameter that was an independent predictor of endometriomas (entropy, 75% Se and 100% Sp) and of the predictive model composed of all parameters that showed statistically significant results at the univariate analysis (100% Se, 100% Sp) outperformed the ones shown by the classic MRI endometrioma features (“T2 shading”, 75.86% Se and 35.71% Sp; “T2 dark spots”, 55.17% Se and 64.29% Sp). Conclusion: Whole-lesion MRI TA has the potential to offer a superior discrimination criterion between endometriomas and HCs compared to the classic evaluation of the two lesions’ MRI signal behaviors

Computer Tomography in the Diagnosis of Ovarian Cysts: The Role of Fluid Attenuation Values

Pathological analysis of ovarian cysts shows specific fluid characteristics that cannot be standardly evaluated on computer tomography (CT) examinations. This study aimed to assess the ovarian cysts’ fluid attenuation values on the native (Np), arterial (Ap), and venous (Vp) contrast phases of seventy patients with ovarian cysts who underwent CT examinations and were retrospectively included in this study. Patients were divided according to their final diagnosis into the benign group (n = 32) and malignant group (n = 38; of which 27 were primary and 11 were secondary lesions). Two radiologists measured the fluid attenuation values on each contrast phase, and the average values were used to discriminate between benign and malignant groups and primary tumors and metastases via univariate, multivariate, multiple regression, and receiver operating characteristics analyses. The Ap densities (p = 0.0002) were independently associated with malignant cysts. Based on the densities measured on all three phases, neoplastic lesions could be diagnosed with 89.47% sensitivity and 62.5% specificity. The Np densities (p = 0.0005) were able to identify metastases with 90.91% sensitivity and 70.37% specificity, while the combined densities of all three phases diagnosed secondary lesions with 72.73% sensitivity and 92.59% specificity. The ovarian cysts’ fluid densities could function as an adjuvant criterion to the classic CT evaluation of ovarian cysts

Ultrasonography in the Differentiation of Endometriomas from Hemorrhagic Ovarian Cysts: The Role of Texture Analysis

The ultrasonographic (US) features of endometriomas and hemorrhagic ovarian cysts (HOCs) are often overlapping. With the emergence of new computer-aided diagnosis techniques, this is the first study to investigate whether texture analysis (TA) could improve the discrimination between the two lesions in comparison with classic US evaluation. Fifty-six ovarian cysts (endometriomas, 30; HOCs, 26) were retrospectively included. Four classic US features of endometriomas (low-level internal echoes, perceptible walls, no solid components, and less than five locules) and 275 texture parameters were assessed for every lesion, and the ability to identify endometriomas was evaluated through univariate, multivariate, and receiver operating characteristics analyses. The sensitivity (Se) and specificity (Sp) were calculated with 95% confidence intervals (CIs). The texture model, consisting of seven independent predictors (five variations of difference of variance, image contrast, and the 10th percentile; 100% Se and 100% Sp), was able to outperform the ultrasound model composed of three independent features (low-level internal echoes, perceptible walls, and less than five locules; 74.19% Se and 84.62% Sp) in the diagnosis of endometriomas. The TA showed statistically significant differences between the groups and high diagnostic value, but it remains unclear if the textures reflect the intrinsic histological characteristics of the two lesions