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Purpose: The purpose of this prospective study was to investigate the proton-beam-induced changes in apparent diffusion coefficient (ADC) values of ocular melanoma treated with proton-beam therapy (PBT) in patients undergoing long-term magnetic resonance imaging (MRI) follow-up and to assess whether variations in ADC constitute a reliable biomarker for predicting and detecting the response of ocular melanoma to PBT., Methods: Seventeen patients with ocular melanoma treated with PBT were enrolled. All patients underwent conventional MRI and diffusion-weighted imaging (DWI) at baseline and 1, 3, 6, and 18 months after the beginning of therapy. Tumor volumes and ADC values of ocular lesions were measured at each examination. Tumor volumes and mean ADC measurements of the five examination series were compared; correlation of ADC values and tumor regression was estimated., Results: Mean ADC values of ocular melanomas significantly increased already 1 month after therapy whereas tumor volume significantly decreased only 6 months after therapy. Pretreatment ADC value of ocular melanomas and early change in ADC value 1 month after therapy significantly correlated with tumor regression., Conclusions: In ocular melanoma treated with PBT, ADC variations precede volume changes. Both pretreatment ADC and early change in ADC value may predict treatment response, thus expanding the role of DWI from diagnostic to prognostic.

Purpose: This study was undertaken to determine the diagnostic capabilities of diffusion-weighted magnetic resonance imaging (DWI) in detecting ileal inflammation in Crohn's disease (CD), and to verify the correlation between the DWI sequences and the Harvey-Bradshaw index (HBI)., Materials and Methods: Twenty patients with an endoscopic-histological diagnosis of CD of the terminal ileum and MR enterography with DWI sequences and HBI were retrospectively selected. Disease activity was visually evaluated on the DWI sequences. In quantitative analysis, the apparent diffusion coefficient (ADC) of the terminal ileum was compared with that of normal ileal loops. Pearson's r was used to verify the correlation between the DWI findings and the HBI., Results: On visual assessment, the accuracy, sensitivity and positive predictive value of DWI for the detection of inflammation were 100%. In the quantitative assessment, the ADC value of the disease-active terminal ileum was significantly lower (p < 0.00001) than that of normal ileal loops. A correlation was found between visual assessment of the terminal ileum with the DWI sequences and HBI; no correlation was found between ADC of the terminal ileum and HBI., Conclusion: DWI sequences may be useful in differentiating actively inflamed small bowel segments from normal small bowel in CD. Though partial, the correlation between DWI sequences and HBI confirms the utility of this technique in the study of patients with CD.

Purpose: This study was undertaken to compare the ultrasound and magnetic resonance imaging parameters of ocular melanoma and to assess their variation after proton-beam therapy., Materials and Methods: Fifteen choroidal melanoma patients treated with proton-beam therapy were enroled in the study. All patients underwent ophthalmologic evaluations, ultrasound, conventional magnetic resonance (MR) imaging and diffusion-weighted MR imaging before the start of therapy and 3 and 6 months after therapy. Basal diameters, thickness, internal reflectivity, tumour volumes and apparent diffusion coefficient (ADC) values of ocular melanomas were measured at each examination. Correlations between internal reflectivity and ADC were investigated., Results: No significant changes were seen in tumour diameters and tumour height as assessed by B-scan and A-scan, respectively. Significant increase in mean tumour internal reflectivity was detected at 6 months (baseline 35 % ± 11; 6 months 48 % ± 8, Tukey-Kramer p = 0.005). On MRI, compared to baseline (mean 547 ± 262 mm(3)), a significant reduction in volume was seen at 6 months (Tukey-Kramer p = 0.045) (mean volume 339 ± 170 mm(3), mean reduction 38 %). A significant increase in ADC (baseline 1,002 ± 109 mm(2)/s) was detected both at 3 and 6 months after proton therapy (respectively, 1,454 ± 90 and 1,833 ± 261 mm(2)/s, both p < 0.001)., Conclusions: By MRI, in particular by ADC assessment, it is possible to detect early variations in melanoma treated by proton-beam therapy. This examination could be used together with ultrasound in the follow-up of this treatment.

Purpose: The aim of this study was to investigate the utility of diffusion-weighted magnetic resonance (MR) imaging for prediction and early detection of response to proton beam therapy in ocular melanoma., Materials and Methods: Ten ocular melanoma patients treated with proton beam therapy were enrolled in the study. All patients underwent conventional MR imaging and diffusion-weighted imaging (DWI) before the start of therapy, and after 1, 3 and 6 months of therapy. Tumour volumes and apparent diffusion coefficient (ADC) values of ocular lesions were measured at each examination. Tumour volumes and mean ADC measurements of the four examination series were compared; correlation of ADC values and tumour regression was investigated., Results: Mean ADC value of ocular melanomas significantly increased as early as 3 months after therapy; tumour volume significantly decreased as early as 6 months after therapy. The ADC values of ocular melanomas before therapy significantly correlated with tumour regression., Conclusions: DWI may provide an early surrogate biomarker for prediction and early detection of tumour response to eye-preserving therapies in ocular melanoma.

The importance of an early identification of hepatic fibrosis has been emphasized, in order to start therapy and obtain fibrosis regression. Biopsy is the gold-standard method for the assessment of liver fibrosis in chronic liver diseases, but it is limited by complications, interobserver variability, and sampling errors. Several noninvasive methods have been recently introduced into clinical routine, in order to detect liver fibrosis early. One of the most diffuse approaches is represented by diffusion-weighted liver MRI. In this review, the main technical principles are briefly reported in order to explain the rationale for clinical applications. In addition, roles of apparent diffusion coefficient, intravoxel incoherent motion, and relative apparent diffusion coefficient are also reported, showing their advantages and limits.

Background: Currently, radiotherapy represents the most widely employed therapeutic option in patients with uveal melanoma. Although the effects of proton beam radiotherapy on uveal melanoma end ocular tissues have been histologically documented, their appearance at MR imaging is still poorly understood. The purpose of our study was to elucidate the magnetic resonance (MR) semiotics of radiotherapy-induced changes to neoplastic tissues and ocular structures in patients with uveal melanoma undergoing secondary enucleation after proton beam radiotherapy. Methods: Nine patients with uveal melanoma who had undergone proton beam radiotherapy, MR imaging, and subsequent secondary enucleation were retrospectively selected. The histopathologic findings evaluated for irradiated tumors were necrosis, fibrosis, and viable tumor, while the histopathologic findings evaluated for extratumoral ocular/periocular tissues were radiation-related intraocular inflammation, vitreous hemorrhage, optic nerve degeneration, iris neovascularization, and periocular fibrotic adhesions. On MR images, the appearance of the abovementioned histologic features was assessed on conventional and diffusion-weighted sequences. Results: T2-weighted sequences performed better in detecting radiation-induced necrosis, fibrosis, optic nerve degeneration, and periocular fibrotic adhesions. T1-weighted sequences were preferable for identifying cataracts, vitreous hemorrhage, and inflammatory complications. Contrast-enhanced T1-weighted sequences were irreplaceable in assessing iris neovascularization, and in confirming inflammatory complications. Conclusions: In the light of their increasing role in the multidisciplinary management of patients with uveal melanoma, radiologists should be aware of the MR appearance of the effects of radiotherapy on neoplastic and ocular tissue, in order to improve the accuracy of follow-up MR examinations. [ABSTRACT FROM AUTHOR]

Objective: We illustrate the magnetic resonance imaging (MRI) features of non-neoplastic tubaric conditions. Background: A variety of pathologic non-neoplastic conditions may affect the fallopian tubes. Knowledge of their imaging appearance is important for correct diagnosis. With recent advances in MRI, along with conventional MR sequences, diffusion-weighted imaging (DWI) sequences are available and may improve lesion characterization by discriminating the nature of the content of the dilated tube. Tubal fluid with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images and no restricted diffusion on DWI is indicative of hydrosalpinx. Content with high signal intensity on T1-weighted images and restricted diffusion on DWI is suggestive of hematosalpinx associated with endometriosis or tubal pregnancy. A dilated tube with variable or heterogeneous signal intensity content on conventional MR sequences and restricted diffusion on DWI may suggest a pyosalpinx or tubo-ovarian abscess. We describe morphological characteristics, MR signal intensity features, enhancement behaviour and possible differential diagnosis of each lesion. Conclusion: MRI is the method of choice to study adnexal pelvic masses. Qualitative and quantitative functional imaging with DWI can be of help in characterization of tubaric diseases, provided that findings are interpreted in conjunction with those obtained with conventional MRI sequences. Teaching Points: • Nondilated fallopian tubes are not usually seen on MR images. • MRI is the method of choice to characterize and localize utero-adnexal masses. • MRI allows characterization of lesions through evaluation of the fluid content's signal intensity. • DWI in conjunction with conventional MRI sequences may improve tissue characterization. • Pelvic inflammatory disease is the most common tubal pathology. [ABSTRACT FROM AUTHOR]

Abstract Objectives To evaluate the effects of diuretic stimulation on Diffusion Weighted Imaging (DWI) and Diffusion Tensor Imaging (DTI) techniques in transplanted kidneys. Methods 33 transplanted kidney recipients underwent DWI and DTI sequences before and after furosemide. Cortical and medullary Apparent Diffusion Coefficient (ADC) and Fractional Anisotropy (FA) values were calculated in transplanted kidneys. Patients were divided into two groups according to their estimated glomerular rate filtration (Group A ≥ 60 ml/min and Group B < 60 ml/min). Wilcoxon matched pairs signed rank test was applied to compare pre- and post-furosemide values. ADC and FA values were compared between the 2 groups using a Mann-Whitney U test. Receiver Operating Curves (ROC) analysis was performed to predict normal renal function. Results Wilcoxon test revealed a statistically significant difference for all pre- and post- ADC and FA values in group B. For group A, a significant difference was found comparing pre- and post-medullary ADC and FA values (p = 0.0151 and p = 0.0054). In the comparison between group A and group B, cortical and medullary mean ADC values were significantly different before and after furosemide. With regard to medullary FA values, a significant difference was found between groups before and after diuretic stimulation (p respectively of 0.004 and 0.042). Comparing cortical FA mean values, no statistical difference was observed between groups before and after furosemide. The highest Area Under Curve values were reported for cortical ADC (0.878) and medullary ADC (0.863) before diuretic bolus. Conclusions In transplanted kidneys, furosemide did not improve the differentiation between normal and reduced function. Highlights • To investigate diuretic stimulation in transplanted kidneys using diffusion MR • Furosemide increases anisotropy in functioning and non-functioning kidneys • Furosemide seems to not reduce the overlap among fractional anisotropy values [ABSTRACT FROM AUTHOR]