Dynamic Contrast Magnetic Resonance Imaging Research Articles

Assessment of Imaging Findings of Renal Carcinoma Subtypes with 3.0T MRI.

The prevalence of renal masses has escalated as a result of the augmented utilization of cross-sectional imaging techniques. The approach to managing renal masses may exhibit variability contingent upon the subtype of renal cell carcinoma (RCC). This research aimed to distinguish between clear cell and papillary RCCs, utilizing dynamic contrast magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). The study assessed the MR images of 112 patients with RCC. Two radiologists independently analyzed tumor size, vascular involvement, signal characteristics in T1- and T2-weighted sequences, the presence of hemosiderin, both microscopic and macroscopic fat content, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm². Seventy patients had clear cell RCC, and 42 had papillary. In the clear cell RCC, microscopic fat content was significantly higher than the papillary RCC (P < 0.001). However, in papillary RCC, hemosiderin content was substantially greater (P = 0.001). On T2-weighted MR images, clear cell RCCs were usually hyperintense, while papillary RCCs were hypointense (P < 0.001). Even though the rapid enhancement pattern was observed in clear cell RCCs, the progressive enhancement pattern was more prevalent in papillary RCCs (P < 0.001). Hyperintensity on T2-weighted images, microscopic fat content, and rapid enhancement pattern may be indicative of clear cell RCC, whereas hypointensity on T2-weighted images, hemosiderin content, and a progressive contrast pattern may be diagnostic for papillary RCC.

The Effect of Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) in the Diagnosis of Breast Cancer Cases

Aim: The aim of this study is to investigate the effect of dynamic contrast magnetic resonance imaging (DCE-MRI) in the diagnosis of breast cancer (BC) and to compare it with ultrasonography (USG).&#x0D; Materials and Methods: In our study, 78 patients who underwent preoperative DCE-MRI and USG in our diagnosis center in TRNC between 2009 and 2022 and were diagnosed with BC histopathologically were investigated retrospectively.Findings obtained according to the BI-RADS classification in both methods, detection of BC, detection of tumor foci (TF) in multiple tumors (multicentric and multifocal tumors) (MT), correct diagnosis rates(CDR)s in invasive lobular cancers (ILC) and invasive ductal cancers (IDC) were compared and the results were evaluated statistically.&#x0D; Results: The mean age of the ILC and MT cases was found to be significantly lower than the IDC and unifocal tumor(UF) cases (p

Radiomic and Artificial Intelligence Analysis with Textural Metrics Extracted by Contrast-Enhanced Mammography and Dynamic Contrast Magnetic Resonance Imaging to Detect Breast Malignant Lesions.

Purpose:The purpose of this study was to discriminate between benign and malignant breast lesions through several classifiers using, as predictors, radiomic metrics extracted from CEM and DCE-MRI images. In order to optimize the analysis, balancing and feature selection procedures were performed. Methods: Fifty-four patients with 79 histo-pathologically proven breast lesions (48 malignant lesions and 31 benign lesions) underwent both CEM and DCE-MRI. The lesions were retrospectively analyzed with radiomic and artificial intelligence approaches. Forty-eight textural metrics were extracted, and univariate and multivariate analyses were performed: non-parametric statistical test, receiver operating characteristic (ROC) and machine learning classifiers. Results: Considering the single metrics extracted from CEM, the best predictors were KURTOSIS (area under ROC curve (AUC) = 0.71) and SKEWNESS (AUC = 0.71) calculated on late MLO view. Considering the features calculated from DCE-MRI, the best predictors were RANGE (AUC = 0.72), ENERGY (AUC = 0.72), ENTROPY (AUC = 0.70) and GLN (gray-level nonuniformity) of the gray-level run-length matrix (AUC = 0.72). Considering the analysis with classifiers and an unbalanced dataset, no significant results were obtained. After the balancing and feature selection procedures, higher values of accuracy, specificity and AUC were reached. The best performance was obtained considering 18 robust features among all metrics derived from CEM and DCE-MRI, using a linear discriminant analysis (accuracy of 0.84 and AUC = 0.88). Conclusions: Classifiers, adjusted with adaptive synthetic sampling and feature selection, allowed for increased diagnostic performance of CEM and DCE-MRI in the differentiation between benign and malignant lesions.

The role of three different contrast-enhanced, abbreviated MRI protocols as a screening tool of hepatocellular carcinoma in patients with chronic hepatitis C virus infection.

Our study aims to assess the role and diagnostic performance of 3 different contrast-enhanced, abbreviated magnetic resonance imaging (MRI) protocols as a screening tool of hepatocellular carcinoma (HCC). Our retrospective study included 80 patients who were screened for HCC: 47 patients revealed 138 focal hepatic lesions. MRI examinations were performed including full CE-MRI protocols. The MRI was done on a 1.5 T machine. Then 3 different abbreviated contrast-enhanced MRI protocols were analysed separately. The standard dynamic contrast MRI and abbreviated protocols were evaluated following the LI-RADS 2018 lexicon diagnostic features. A considerable overall kappa (k) agreement between the abbreviated 1, 2, and 3 protocols on LI-RADS classification was noted with k = 0.865. There was almost perfect agreement between all abbreviated protocols and full standard protocol on LI-RADS classification, with k = 0.890. As regards the k agreement on LI-RADS classification, there was a considerable highest agreement between the abbreviated 1 protocol and the full standard protocol, with k = 0.980. The abbreviated 1 and 2 protocols showed high diagnostic performance on LI-RADS classification of lesions, with 100% sensitivity, specificity, PPV, NPV, and accuracy, while the abbreviated 3 protocol showed a lesser but comparable sensitivity 96.9%, NPV 99.4, and accuracy 99.4%. Abbreviated contrast-enhanced MRI protocols can be used as a screening tool for the detection of HCC, with high sensitivity, specificity, PPV, NPV, and accuracy close to the full protocol. There was a considerable highest agreement between the abbreviated 1 protocol and the full standard protocol. Subsequently, this protocol can be used as a standard protocol for screening high-risk patients.

A Correlative Study Between IVIM-DWI Parameters and the Expression Levels of Ang-2 and TKT in Hepatocellular Carcinoma.

BackgroundNoninvasive evaluation of the expression of angiopoietin-2 (Ang-2) and transketolase (TKT) in hepatocellular carcinoma (HCC) is of great significance for the clinical development of individualized treatment plans. However, the correlation between intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) and the expression of Ang-2 and TKT has not been reported. We sought to investigate the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.MethodsConventional non-enhanced magnetic resonance imaging (MRI) and IVIM-DWI and dynamic contrast MRI were performed for 61 patients with HCC before surgical treatment. Various IVIM-DWI parameters, such as apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D*) and fraction of fast apparent diffusion coefficient (f), were calculated using Function-MADC software. Expression levels of Ang-2 and TKT in HCC were detected via immunohistochemical staining and classified into two grades. Independent sample t tests were used to compare differences in parameters between the two groups. The Spearman rank correlation test was used to analyze the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.ResultsThe D* and f values were significantly higher in the high Ang-2 group than in the low Ang-2 group; there were no obvious between-group differences in ADC and D. Ang-2 expression was positively correlated with D* and f but not with ADC and D. The ADC and D values were significantly lower in the high TKT group than in the low TKT group, whereas the between-group differences for D* and f were not significant. TKT expression was negatively correlated with ADC and D but not with D* and f.ConclusionsIVIM-DWI can be used to evaluate Ang-2 and TKT expression in HCC.

MRI evaluation of soft tissue vascular malformations.

Background:Soft tissue vascular malformations are not uncommonly encountered in clinical practice and are often mistaken for other pathologies. Vascular anomalies are divided into vascular tumors and malformations. Vascular malformations progressively increase in size with increasing age and are classified into low-flow (venous, lymphatic, veno-lymphatic, capillary and capillary venous) and high-flow malformations (arteriovenous malformations (AVM) and arteriovenous fistula (AVF)) depending on the presence or absence of arterial flow. Aim:Aim of this study is to evaluate the Magnetic resonance imaging (MRI) features of the soft tissue vascular malformations and to classify the lesions depending on flow pattern. Materials and Methods:A total of 52 patients of soft tissue vascular malformations were included in this study over a period of 3 years. All patients underwent detailed clinical examination and dynamic post contrast MRI evaluation. Doppler and ultrasound were done as an adjunct. Results:There were 31 females and 21 male patients with age ranging from 9 to 34 years. In total 33 venous, 11 lymphatic, 8 veno-lymphatic malformations were seen. No case of high-flow malformation was seen. Majority of the lesions involved the head and neck region and the extremities. Fat saturated T2WI, STIR, and 3D dynamic post contrast sequences were found to be the most useful MRI sequences. Conclusion:MRI is the modality of choice for evaluating the soft tissue vascular malformations. It depicts the extent of the lesion, classifies the lesions into low or high flow and helps in treatment planning.

Interobserver Agreement of Magnetic Resonance Imaging of Liver Imaging Reporting and Data System Version 2018.

This study aimed to assess the interobserver agreement of magnetic resonance (MR) imaging of Liver Imaging Reporting and Data System version 2018 (LI-RADS v2018). Retrospective analysis was done for 119 consecutive patients (77 male and 42 female) at risk of hepatocellular carcinoma who underwent dynamic contrast MR imaging. Image analysis was done by 2 independent and blinded readers for arterial phase hyperenhancement, washout appearance, enhancing capsule appearance, and size. Hepatic lesions were classified into 7 groups according to LI-RADS v2018. There was excellent interobserver agreement of both reviewers for LR version 4 (κ = 0.887, P = 0.001) with 90.76% agreement. There was excellent interobserver agreement for nonrim arterial phase hyperenhancement (κ = 0.948; 95% confidence interval [CI], 0.89-0.99; P = 0.001), washout appearance (κ = 0.949; 95% CI, 0.89-1.0; P = 0.001); and enhancing capsule (κ = 0.848; 95% CI, 0.73-0.97; P = 0.001) and excellent reliability of size (interclass correlation, 0.99; P = 0.001). There was excellent interobserver agreement for LR-1 (κ = 1.00, P = 0.001), LR-2 (κ = 0.94, P = 0.001), LR-5 (κ = 0.839, P = 0.001), LR-M (κ = 1.00, P = 0.001), and LR-TIV (κ = 1.00; 95% CI, 1.0-1.0; P = 0.001), and good agreement for LR-3 (κ = 0.61, P = 0.001) and LR-4 (κ = 0.61, P = 0.001). MR imaging of LI-RADS v2018 is a reliable imaging modality and reporting system that may be used for standard interpretation of hepatic focal lesions.

Evaluation of MRI based diagnostic algorithm for intra-axial brain masses: A single centre experience

Background and Purpose: Preoperative evaluation and differentiation of intra-axial brain masses is essential for therapy and prognosis. The integrated Magnetic Resonance Imaging (MRI) techniques such as Diffusion Weighted Imaging (DWI), Magnetic Resonance Spectroscopy (MRS) and Dynamic Susceptibility Contrast (DSC) MRI allow insights into tumour anatomy and physiology. Our study was designed to find the sensitivity, specific and accuracy of a diagnostic algorithm comprising of these techniques. Materials and Methods: Thirty consecutive immunocompetent patients with treatment naive intra-axial brain masses underwent MRI from July 2016 to July 2017. Conventional and DWI, MRS and MR perfusion scans were performed using 1.5 T MR imaging system. The following cut-off values (ADC ?1.1 /100mm2, intralesional Cho/NAA > 2.2, perilesional Cho/NAA >1 and rCBV >1.75) were applied to the diagnostic strategy algorithm. Histopathological analysis served as the gold standard. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were obtained. Results: Twenty one of 30 cases were correctly classified using the diagnostic algorithm. One case of primary central nervous system lymphoma (PCNSL) was misdiagnosed as metastasis, 2 cases of high-grade neoplasm (HGN) as brain abscesses, 1 case of HGN as metastasis, 1 case of HGN as low-grade neoplasm (LGN), 1 case of LGN as HGN, 1 case of LGN as abscess / tumefactive demyelinating lesion (TDL), 1 case of brain abscess as HGN, and 1 case of metastasis (breast carcinoma) as HGN. Conclusion: Diagnosing intra-axial brain masses using a combination of advanced imaging techniques (MRS, MR perfusion and ADC) is fairly accurate.

Buccal Monomorphic Adenoma: a case report

Background: Minor salivary gland benign tumors constitute a very small fraction of salivary gland tumors. The majority of monomorphic adenomas arise from the main salivary glands but rarely these can arise from the minor salivary glands of the buccal mucosa. Case presentation: We present 60-years old female who reported for the slow growing swelling on her right cheek for over three years. She was diagnosed of having monomorphic adenoma of the minor salivary gland after ultrasound (US), contrast enhanced computerized tomography (CECT) and magnetic resonance imaging (MRI) studies with additional confirmation by fine needle aspiration cytology (FNAC). Conclusion: Dynamic contrast MRI played a key role in assessment of the mass for its benign nature before the surgical contemplation. This was also confirmed subsequently by the histopathology examination.

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) and Diffusion Weighted MR Imaging (DWI) for Differentiation between Benign and Malignant Salivary Gland Tumors.

Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists. The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE-) MRI and diffusion-weighted MRI (DWI) can indicate the characteristics of tumor tissue. DCE-MRI analysis is based on the parameters of time intensity curve (TIC) before and after contrast agent injection. This method has the potential to identify the angiogenesis of tumors. DWI analysis is performed according to diffusion of water molecules in a tissue for determination of the cellularity of tumors. According to the literature, these methods cannot be used individually to differentiate benign from malignant salivary gland tumors. An effective approach could be to combine the aforementioned methods to increase the accuracy of discrimination between different tumor types. The main objective of this study is to explore the application of DCE-MRI and DWI for assessment of salivary gland tumor types.

Transfer characteristics of arterial pulsatile force in regional intracranial tissue using dynamic diffusion MRI: A phantom study

IntroductionTo clarify the mechanism underlying apparent diffusion coefficient (ADC) changes in regional intracranial tissue during the cardiac cycle, we investigated relationships among ADC changes, volume loading, and intracranial pressure using a hemodialyzer phantom in magnetic resonance imaging (MRI). Materials and MethodsThe hemodialyzer phantom consisted of hollow fibers (HF), the external space of HFs (ES), and a gateway of dialysis solution, filled with syrup solution and air. The high-volume and low-volume loadings were periodically applied to HFs by a to-and-fro flow pump, and syrup solution was permitted to enter or leave HFs during the volume loading cycles. ADC maps at each volume loading phase were obtained using ECG-triggered single-shot diffusion echo-planar imaging. Dynamic phase contrast MRI was also used to measure volume loading to the phantom. We compared the ADC changes, volume loading, and intracranial pressure in the phantom during the cardiac cycle. ResultsADC changes synchronized significantly with absolute volumetric flow rate change. The maximum ADC change was higher in high-volume loading cycles than in low-volume loading cycles. Results showed that the water molecules in ES fluctuated according to the force transferred from HF to ES. ADC changes were dependent upon the volumetric flow rate during the cardiac cycle. ConclusionsOur original phantom allowed us to clarify the mechanism underlying water fluctuations in intracranial tissues. Measurement of maximum changes in ADC is an effective method to define the transfer characteristics of the arterial pulsatile force in regional intracranial tissue.

Intratumoral heterogeneity of the distribution of kinetic parameters in breast cancer: comparison based on the molecular subtypes of invasive breast cancer

To evaluate the distribution pattern of kinetic parameters in breast cancers with various molecular subtypes. This study was approved by institutional review board and was compliant with HIPAA. We classified 192 invasive breast cancers of 186 patients into four molecular subtypes using hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) results and evaluated the distribution pattern of kinetic parameters (percent volume of kinetic types relative to the tumor volume) in the molecular subtypes. In the delayed phase, all three types of kinetic parameter (persistent, plateau, and washout pattern) were observed in each molecular subtype without any dominant type of kinetic parameter. The percentages of washout pattern in the HR+ and HER2- type and triple negative (TN) cancers tended to be lower than those in the other molecular subtype cancers. Each molecular subtype of invasive breast cancer showed a heterogeneous kinetic pattern in dynamic-contrast magnetic resonance imaging (MRI). The HR+/HER2- cancers and the TN cancers had relatively lower percentages of washout pattern. When a manual assessment of the kinetic parameters is performed, close attention should be paid in order to identify the malignant washout kinetic pattern, particularly in HR+/HER2- cancer and TN cancer.

Nosology of juvenile muscular atrophy of distal upper extremity: from monomelic amyotrophy to Hirayama disease--Indian perspective.

Since its original description by Keizo Hirayama in 1959, “juvenile muscular atrophy of the unilateral upper extremity” has been described under many nomenclatures from the east. Hirayama disease (HD), also interchangeably referred to as monomelic amyotrophy, has been more frequently recognised in the west only in the last two decades. HD presents in adolescence and young adulthood with insidious onset unilateral or bilateral asymmetric atrophy of hand and forearm with sparing of brachioradialis giving the characteristic appearance of oblique amyotrophy. Symmetrically bilateral disease has also been recognized. Believed to be a cervical flexion myelopathy, HD differs from motor neuron diseases because of its nonprogressive course and pathologic findings of chronic microcirculatory changes in the lower cervical cord. Electromyography shows features of acute and/or chronic denervation in C7, C8, and T1 myotomes in clinically affected limb and sometimes also in clinically unaffected contralateral limb. Dynamic forward displacement of dura in flexion causes asymmetric flattening of lower cervical cord. While dynamic contrast magnetic resonance imaging is diagnostic, routine study has high predictive value. There is a need to lump all the nomenclatures under the rubric of HD as prognosis in this condition is benign and prompt diagnosis is important to institute early collar therapy.

Clinical and radiological profile of Hirayama disease: A flexion myelopathy due to tight cervical dural canal amenable to collar therapy.

Background:Hirayama disease (HD) is benign focal amyotrophy of the distal upper limbs, often misdiagnosed as motor neuron disease. Routine magnetic resonance imaging (MRI) is often reported normal.Objective:To study the clinicoradiological profile of hand wasting in young males.Materials and Methods:Patients presenting with insidious-onset hand wasting from March 2008 to May 2011 were evaluated electrophysiologically. Cervical MRI in neutral position was done in 11 patients and flexion contrast imaging was done in 10 patients.Results:All patients were males less than 25 years of age, with median age 23 years, except one patient who was 50 years old. Duration of illness was 3 months to 3 years. All (100%) had oblique amyotrophy, four (36%) cold paresis, 10 (91%) minipolymyoclonus and three (27%) had fasciculations. Regional reflexes were variably absent. Two patients (18%) had brisk reflexes of lower limbs with flexor plantars. Electromyography (EMG) showed chronic denervation in the C7-T1 myotomes. Neutral position MRI showed loss of cervical lordosis in 10/11 (91%), localized lower cervical cord atrophy in 9/11 (82%), asymmetric cord flattening in 11/11 (100%) and intramedullary hyperintensity in 2/11 (18%); flexion study showed loss of dural attachment, anterior displacement of dorsal dura, epidural flow voids in 9/10 (90%) and enhancing epidural crescent in 10/10 (100%). Clinical profile, imaging and electrophysiological findings of the patient aged 50 years will be described in detail as presentation at this age is exceptional. Collar therapy slowed progression in most cases.Conclusion:Clinical features of HD corroborated well with electrophysiological diagnosis of anterior horn cell disease of lower cervical cord. While dynamic contrast MRI is characteristic, routine studies have a high predictive value for diagnosis. Prompt diagnosis is important to institute early collar therapy.

New analysis of the hypertension mechanism in bevacizumab-treated patients using 3-tesla dynamic contrast-enhanced magnetic resonance imaging.

450 Background: Vascular endothelial growth factor (VEGF) signaling inhibitors, such as bevacizumab (BV), leads to endothelial dysfunction and microvascular rarefaction in noncancer tissue. Angiotensin II has been reported to induce VEGF production by inhibiting VEGF, but the reasons for activation of angiotensin II are unclear. We conducted a study to examine the relationship between renin-angiotensin axis and renal blood perfusion using dynamic contrast magnetic resonance imaging (DCE-MRI) in colorectal cancer patients. Methods: Sixteen patients with colorectal cancer were enrolled. They received BV+FOLFIRI regimen as second line. DCE-MRI was performed before the treatment and after 12th courses. Renin, angiotensin I, angiotensin II and aldosterone were examined before treatment and at 3, 5, 8, 12th courses. DCE-MRI parameters, Area under the time-intensity curve over the first 90 seconds after injection of contrast material (AUC90) and volume transfer constant of contrast material (Ktrans, Kep) were calculated in the normal kidney and examine the correlation with renin-angiotensin axis. Results: All DCE-MRI parameters decreased significantly after 12th courses compared with before treatment (Variables median: Ktrans -1.51, Kep -2.30, AUC90 -26.0, P &lt; 0.001, all). A decrease in Kep correlated with higher renin, angiotensin I and angiotensin II (renin: P =0.001, angiotensin I: P =0.003, angiotensin II: P =0.002, respectively). A decrease in AUC90 correlated with higher aldosterone (P =0.005). Blood pressure did not correlate with each DCE-MRI parameters. Conclusions: VEGF inhibition decreases vessel permeability and raises interstitial pressure in normal kidney. Our data suggest that renin-angiotensin axis is also one mechanism of hypertension caused by BV. No significant financial relationships to disclose.

Phase II trial of neoadjuvant chemotherapy (NCT) with weekly nanoparticle albumin-bound paclitaxel (Nab-P), carboplatin (CBP), and bevacizumab (BEV) in women with clinical stages II-III breast cancer (BC): Pathologic response prediction by changes in angiogenic volume (AV) by dynamic contrast magnetic resonance imaging (DCE-MRI).

604 Background: BEV in combination with paclitaxel improves the outcome of previously untreated metastatic BC patients (Miller et al NEJM 357, 2007). We hypothesized that adding BEV to weekly Nab-P and CBP as NCT would be well tolerated, have improved anti-tumor activity and early changes in AV by DCE-MRI would correlate with pathologic response. Methods: Pts with clinical stages II/III and HER2-non- overexpressing BC received Nab-P 100 mg/m2 IV and CBP AUC=2 IV on days 1, 8, and 15 in combination with BEV 10 mg/kg on days 1 and 15 administered every 28 days for 5 cycles; in the sixth cycle BEV was omitted. DCE-MRI was performed pre NCT, after 2 cycles and prior to the definitive surgery. Pathologic complete response (pCR) was defined as absence of invasive tumor in breast and axilla. Results: Thirty of planned 33 pts were enrolled. The median age was 48 years; 21 (70%) pts were premenopausal; 19 (63%) pts had ER/PR positive BC and 11 (37%) had triple negative BC (TNBC). Treatment was well tolerated with exception of grade 3 and 4 neutropenia in 14 (48%) and 2 (7%) and thrombocytopenia in 2 (7%) and 1 (3%) respectively. Thus far, 17 pts finished NCT; 12 (71%) received all 6 cycles with remaining 5 (29%) pts received < 3 cycles of NCT. The primary reason for not completing all 6 cycles was myelosuppression (n = 4) and disease progression (n = 1). Fourteen pts had definitive surgery: 6 (43%) had lumpectomy, and 8 (57%) had mastectomy. Three (21%) pts had pCR and 3 (21%) had microscopic residual disease (MRD). In the TNBC group the pCR rate was 50% (3 out of 6 pts). At the end of cycle 2, the relative AV decreased from 73% ± 10% in baseline DCE-MRI to 38% ± 37% in pts with pCR and MRD. The relative AV increased from 68% ± 25% in baseline DCE-MRI to 87% ± 18% in non-responders. The changes in relative AV were significantly different between responders and non-responders (p = 0.016). Conclusions: The combination was more myelosuppressive than expected. Early change in relative AV by DCE-MRI may predict response to NCT. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Abraxis BioScience, Roche

Utility of preoperative dynamic magnetic resonance imaging of the pancreas in diagnosing tumor-forming pancreatitis that mimics pancreatic cancer: Report of a case

The differential diagnosis of pancreatic carcinoma and tumor-forming pancreatitis remains difficult, and this situation can cause serious problems because the management and prognosis of these two focal pancreatic masses are entirely different. We herein report a case of tumor-forming pancreatitis that mimics pancreatic carcinoma in an 80-year-old woman. Computed tomography showed a solid mass in the head of the pancreas, and endoscopic retrograde cholangiopancreatography showed a complete obstruction of the main pancreatic duct in the head of the pancreas. Dynamic contrastenhanced magnetic resonance imaging (MRI) demonstrated a time-signal intensity curve (TIC) with a slow rise to a peak (1 min after the administration of the contrast material), followed by a slow decline at the pancreatic mass, indicating a fibrotic pancreas. Under the diagnosis of tumor-forming pancreatitis, the patient underwent a segmental pancreatectomy instead of a pancreaticoduodenectomy. The histopathology of the pancreatic mass was chronic pancreatitis without malignancy. The pancreatic TIC obtained from dynamiccontrast MRI can be helpful to differentiate tumor-forming pancreatitis from pancreatic carcinoma and to avoid any unnecessary major pancreatic surgery.

Correlative dynamic contrast MRI and microscopic assessments of tumor vascularity in RIP‐tag2 transgenic mice

The purpose of this study was to define the feasibility of dynamic contrast-enhanced magnetic resonance imaging (MRI) to estimate the vascular density and leakiness of spontaneous islet cell tumors in RIP-Tag2 transgenic mice. Dynamic T(1)-weighted spoiled gradient echo (SPGR) imaging at 2.0 T was performed in 17 RIP-Tag2 mice using a prototype blood pool macromolecular contrast medium (MMCM), albumin-(Gd-DTPA)(35). Kinetic analysis of the dynamic enhancement responses based on a two-compartment model was used to estimate fractional plasma volume (fPV) and the coefficient of endothelial permeability (K(PS)) for each tumor. The MRI estimate of fPV was correlated on a tumor-by-tumor basis with corresponding microscopic measurements of vascular density. The fPV assays by MMCM-enhanced imaging ranged from 2.4%-14.1% of tissue volume. Individual tumor fPV values correlated significantly (r = 0.79, P < 0.001) with the corresponding microscopic estimates of vascularity consisting of the combined area densities of lectin-perfused microvessels plus erythrocyte-stained blood lakes. A biotinylated derivative of the albumin-based MMCM confirmed extravasation of the contrast agent from some tumor blood vessels and accumulation in 25% of blood lakes. The K(PS) values ranged from 0 (no detectable leak) to 0.356 mL/min/100 cm(3). Dynamic MMCM-enhanced MRI is feasible in RIP-Tag2 pancreatic tumors, yielding estimates of vascular permeability and microscopically validated measurements of vascular richness.

Longitudinally Monitoring Chemotherapy Effect of Malignant Musculoskeletal Tumors With In Vivo Proton Magnetic Resonance Spectroscopy

To investigate the value of in vivo proton (H) magnetic resonance spectroscopy (MRS) in longitudinally monitoring the treatment response of malignant musculoskeletal tumors under chemotherapy. Twenty-three studies in 3 patients with bone and soft-tissue tumors (2 lymphomas and 1 alveolar soft part sarcoma) were included in the study. The dynamic contrast-enhanced magnetic resonance (MR) imaging and single-voxel proton MRS with 135 milliseconds of echo time were carried out using a whole-body 1.5-T scanner and a surface coil. The volume of interest within the lesion was positioned on the area of early enhancement according to the finding of the first dynamic contrast-enhanced MR imaging with subtraction. The choline and water intensities were measured at the peak areas at 3.2 and 4.5 ppm. The choline-water ratios were calculated as well. Statistical analysis was performed by using Kruskal-Wallis 1-way analysis of variance test ().(Table is included in full-text article.) The changes observed on the dynamic contrast-enhanced MR images and tumor size after chemotherapy fell into 2 clearly distinct patterns: subsequent partial response (patients 1 and 2) and progressive disease (patient 3). The choline concentration, choline-volume ratio, and choline-water ratio in the first 2 patients were reduced substantially to zero in the follow-up MRS. In the remaining patient, the choline, choline-volume ratio, and choline-water ratio remained high in the follow-up MRS. The water concentration and water-volume ratio between the 3 patients showed significant statistical differences (Kruskal-Wallis test, P = 0.004 and 0.039). In vivo proton MRS is technically feasible for the evaluation of musculoskeletal tumors. Choline can be detected in malignant bone and soft-tissue tumors, and the early metabolite changes after chemotherapy can also be identified in the in vivo proton MRS by using a standard clinical-use 1.5-T MR scanner and a surface coil. The decline of choline after treatment in malignant bone and soft-tissue tumors correlates with the response of the dynamic contrast MR images and the tumor size. The information provided with MR imaging and proton MRS may improve the diagnostic specificity of MR examination in the follow-up of tumor treatment.

Dynamic Contrast-Enhanced Magnetic Resonance Imaging Pharmacodynamic Biomarker Study of Sorafenib in Metastatic Renal Carcinoma

Sorafenib is an antiangiogenic agent with activity in renal cancer. We conducted a randomized trial to investigate dynamic contrast magnetic resonance imaging (DCE-MRI) as a pharmacodynamic biomarker. Patients were randomly assigned to placebo or 200 or 400 mg twice per day of sorafenib. DCE-MRI was performed at baseline and 4 weeks. DCE-MRI parameters, area under the contrast concentration versus time curve 90 seconds after contrast injection (IAUC(90)), and volume transfer constant of contrast agent (K(trans)) were calculated for a metastatic site selected in a blinded manner. Primary end point was change in K(trans). Of the 56 assessable patients, 48 underwent two MRIs; 44 MRIs were assessable for study end points. Mean K(trans) log ratios were 0.131 (standard deviation [SD], 0.315), -0.148 (SD, 0.382), -0.271 (SD, 0.499) in placebo, 200- and 400-mg cohorts, respectively (P = .0077 for trend) corresponding to changes of +14%, -14%, and -24%. IAUC(90) log ratios were 0.041 (SD, 0.197), -0.040 (SD, 0.132), -0.356 (SD, 0.411), respectively (P = .0003 for trend), corresponding to changes of +4%, -4%, and -30%. Using a log-rank test, IAUC(90) and K(trans) changes were not associated with progression-free survival (PFS). Patients with high baseline K(trans) had a better PFS (P = .027). IAUC(90) and K(trans) are pharmacodynamic biomarkers for sorafenib, but variability is high and magnitude of effect is less than previously reported. Changes in DCE-MRI parameters after 4 weeks of sorafenib are not predictive of PFS, suggesting that these biomarkers are not surrogate end points. The value of baseline K(trans) as a prognostic or predictive biomarker requires additional study.