Zareen Fatima

Diagnosis of colorectal hepatic metastases: Comparison of contrast‐enhanced CT, contrast‐enhanced US, superparamagnetic iron oxide‐enhanced MRI, and gadoxetic acid‐enhanced MRI

To compare the diagnostic accuracy of contrast‐enhanced computed tomography (CE‐CT), contrast‐enhanced ultrasonography (CE‐US), superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), and gadoxetic acid‐enhanced MRI (Gd‐EOB‐MRI) in the evaluation of colorectal hepatic metastases.

Mass-forming autoimmune pancreatitis and pancreatic carcinoma: differential diagnosis on the basis of computed tomography and magnetic resonance cholangiopancreatography, and diffusion-weighted imaging findings.

To differentiate mass‐forming autoimmune pancreatitis (AIP) from pancreatic carcinoma by means of analysis of both computed tomography (CT) and magnetic resonance imaging (MRI) findings.

Magnetic resonance diffusion-weighted imaging in the characterization of pancreatic mucinous cystic lesions

AIM The aim of the study was to evaluate the utility of diffusion-weighted imaging (DWI), including apparent diffusion coefficient (ADC) measurement, in order to differentiate mucinous cystic neoplasms (MCNs) from intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. MATERIALS AND METHODS Fifty cases of IPMN with a total of 62 lesions, and eight cases of MCN, were retrospectively selected for the study. The cases of IPMN were selected using multimodality clinical or histopathological criteria, while all MCN lesions were histopathologically proven. DWI was carried out using b values of 500 and 1000s/mm(2). Visual assessment was performed by two radiologists who used two categories (low-iso or high signal intensity). ADC values of the lesions were also calculated. Fishers exact test and the Mann-Whitney U test were used for statistical analysis. RESULTS All IPMN lesions demonstrated low-iso signal intensities compared with the pancreatic parenchyma on DWI. Two of the MCN lesions demonstrated low-iso signal intensities, and six lesions demonstrated high signal intensities. The ADC values for IPMNs (mean 2.9 ± 0.024 × 10(-3)mm(2)/s) were significantly higher than those for MCNs (mean 2.1 ± 0.30 × 10(-3)mm(2)/s). ROC analysis showed an optimal cut-off value of 2.4 × 10(-3)mm(2)/s for differentiating between the two types of lesions, providing a sensitivity of 98% and a specificity of 88%. CONCLUSION The results of the present study suggest that ADC values in mucinous cystic lesions of the pancreas can be advantageous for their characterization into IPMN and MCN.

Diffusion-weighted imaging in optic neuritis.

Purpose To evaluate imaging characteristics of optic nerves by using magnetic resonance imaging, especially diffusion-weighted imaging (DWI) with apparent diffusion coefficient measurements in acute and chronic phases of optic neuritis (ON). Materials and Methods A retrospective study was conducted by using records of 14 patients with clinically suspected acute ON (15 nerves), 5 chronic ON (7 nerves), and 11 normal volunteers with no eye symptoms were used as controls. Magnetic resonance imaging was performed by a 1.5T scanner. Affected nerves were evaluated for sizes, signal characteristics on DWI and T2-weighted imaging (T2WI), contrast enhancement, and apparent diffusion coefficient values. Visually assessed characteristics were compared between the acute and chronic, whereas apparent diffusion coefficient values were assessed among acute ON, chronic ON, and the control groups by using the Fisher exact test and Mann-Whitney U test. Results There were significant differences in the diameter of the optic nerves, hyperintensity on DWI, and enhancement characteristics on post-enhanced images in acute and chronic phases of ON (P = .0001, P < .0001, and P = .0022, respectively), apparent diffusion coefficient values of the optic nerves in acute ON, chronic ON, and control groups also differed significantly from each other. Conclusion In conclusion, DWI can add valuable information in assessment of damage to nerve and neuronal barriers and thus in predicting recovery in cases of ON.

A Comparison of Mean Displacement Values Using High b-Value Q-Space Diffusion-weighted MRI with Conventional Apparent Diffusion Coefficients in Patients with Stroke

RATIONALE AND OBJECTIVES Q-space analysis using high b-value diffusion-weighted magnetic resonance (MR) data provides information on tissue microstructure in contrast to conventional MR imaging (MRI) based on low b-value diffusion-weighted imaging (DWI). The purpose of this study was to evaluate the use of mean displacement (MDP) map in stroke patients using q-space diffusion-weighted MRI (QSI). MATERIALS AND METHODS Twenty-one patients presenting with a total of 22 acute or subacute cerebral infarctions were included. MR protocol consisted of conventional MR sequences, DWI (b-value; 1000 s/mm(2)) and QSI (b-value; maximum 12,000 s/mm(2)). Apparent diffusion coefficient (ADC) maps of conventional DWI and MDP maps of QSI data were obtained and compared in the ischemic lesions and corresponding normal tissues. RESULTS Decreased ADC values were present in all lesions. There was no correlation between ADC and MDP values in the lesions (r = 0.21). MDP values of the lesions were 8.60 ± 1.26 μm (mean ± SD). Most of the lesions (16/22) had higher MDP values than normal brain tissue. Three lesions showed lower MDP values and three showed mixed MDP values. CONCLUSIONS The MDP maps using QSI data provides additional information for stroke patients compared to conventional DWI.

Time-resolved contrast-enhanced magnetic resonance digital subtraction angiography (MRDSA) in an infant with congenital pial arteriovenous fistula in the brain: a case report

IntroductionEvaluation of the congenital vascular lesions of the brain requires multiple conventional intra-arterial digital subtraction angiographic examinations which have many associated risks including exposure to ionizing radiations. Magnetic resonance digital subtraction angiography is a non-invasive procedure with no related risks of radiation exposure. This technique can be of greater clinical significance in diagnosis and treatment planning of neurovascular abnormalities among children who are at far greater risk of invasive procedures like intra-arterial digital subtraction angiography.Case reportWe report a congenital pial arteriovenous fistula in an infant which is a rare vascular lesion and has recently been identified as different from other vascular malformations. Magnetic resonance digital subtraction angiography provided hemodynamic information in absolute agreement with intra-arterial digital subtraction angiography indicating its significance in evaluating vascular lesions.DiscussionMagnetic resonance digital subtraction angiography can be used in children in conjunction with intra-arterial digital subtraction angiography to minimize the cumulative radiation dose and multiple anesthesias.

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

AbstractObjectivesThe purposes of this MR-based study were to calculate q-space imaging (QSI)–derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI).MethodsMRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery.ResultsADC and MDP values were found to have a strong correlation: r = 0.78 (P = <0.0001). Both ADC and MDP values had a significant negative association with TCC: r = –0.53 (p = 0.02) and –0.48 (P = 0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters.ConclusionIn meningiomas, both ADC and MDP may be representative of cell density.Key Points• Diffusion-weighted MRI offers possibilities to assess the aggressiveness of meningiomas. • The q-space imaging-derived mean displacement correlates strongly with apparent diffusion coefficients. • Both diffusion parameters showed a strong negative association with tumour cell counts. • Derived mean displacement may help assess the aggressiveness of meningiomas preoperatively.

Mean displacement map of spine and spinal cord disorders using high b-value q-space imaging-feasibility study

Background Q-space analysis is a new metric that uses multiple, high b-value, diffusion-weighted magnetic resonance (MR) data. This technique shows promising results as a tool to provide information complementary to that of other imaging techniques used on biological tissue in vivo. Purpose To investigate the use of a mean displacement (MDP) map of high b-value, q-space imaging (QSI) to characterize spinal and spinal cord lesions in vivo. Material and Methods Eight patients with spine or spinal cord disorders (two neurinomas, one myeloma, three cases of syringohydromyelia, and two cases of cervical spondylosis) were included. The MR imaging protocol consisted of conventional MR sequences, conventional diffusion-weighted imaging (DWI; b = 1000), and high b-value QSI with a maximum q value of 836.9 cm−1. Apparent diffusion coefficient (ADC) maps of conventional DWI and MDP maps of QSI data were obtained and region-of-interest analyses for the lesions were performed. Results MDP values of normal spinal cord, cerebrospinal fluid (CSF), and tumor parenchyma were 6.57 ± 0.52, 17.6 ± 2.75, and 8.49 ± 2.09, respectively (µm, mean ± standard deviation). In general, MDP maps were not well correlated with the corresponding ADC maps at the pathologic lesions. Spondylotic lesions tended to have higher MDP values than normal spinal cord, whereas syringohydromyelia produced MDP values slightly lower than those of CSF. Conclusion The heterogeneous MDP values were probably due to differences in tissues and pathologic structures. This technique has potential to provide additional clinical information to that obtained with conventional MR imaging.

High b-value q-space analyzed diffusion-weighted MRI using 1.5 tesla clinical scanner; determination of displacement parameters in the brains of normal versus multiple sclerosis and low-grade glioma subjects.

We aimed to determine the displacement parameters in the brains of normal individuals relative to brain parenchymal abnormalities, such as multiple sclerosis (MS) and low‐grade glioma, by q‐space imaging (QSI) using 1.5‐T magnetic resonance (MR) scanner.

Case 193: Neuroferritinopathy—A Brain Iron Accumulation and Neurodegenerative Disorder

This patient has clinical and imaging features that are essentially diagnostic of a recently identified entity known as neuroferritinopathy.