Reduced Field-of-View Diffusion-Weighted Magnetic Resonance Imaging of the Pancreas: Comparison with Conventional Single-Shot Echo-Planar Imaging

ObjectiveTo investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI.ResultsOn qualitative analysis, reduced FOV DWI showed better anatomic structure visualization (2.76 ± 0.79 at b = 0 s/mm² and 2.81 ± 0.64 at b = 400 s/mm²), lesion conspicuity (3.11 ± 0.99 at b = 0 s/mm² and 3.15 ± 0.79 at b = 400 s/mm²), IQ score (8.51 ± 2.05 at b = 0 s/mm² and 8.79 ± 1.60 at b = 400 s/mm²), and higher clinical utility (3.41 ± 0.64), as compared to full FOV DWI (anatomic structure, 2.18 ± 0.59 at b = 0 s/mm² and 2.56 ± 0.47 at b = 500 s/mm²; lesion conspicuity, 2.55 ± 1.07 at b = 0 s/mm² and 2.89 ± 0.86 at b = 500 s/mm²; IQ score, 7.13 ± 1.83 at b = 0 s/mm² and 8.17 ± 1.31 at b = 500 s/mm²; clinical utility, 3.14 ± 0.70) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI (2.65 ± 0.68) at b = 0 s/mm² (full FOV DWI, 2.41 ± 0.63) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas (1.061 × 10^-3 mm²/s ± 0.133 at reduced FOV and 1.079 × 10^-3 mm²/s ± 0.135 at full FOV) and neuroendocrine tumors (0.983 × 10^-3 mm²/s ± 0.152 at reduced FOV and 1.004 × 10^-3 mm²/s ± 0.153 at full FOV) were significantly lower than those of parenchyma (1.191 × 10^-3 mm²/s ± 0.125 at reduced FOV and 1.218 × 10^-3 mm²/s ± 0.103 at full FOV) (p < 0.05).ConclusionReduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.     

Atypical Unilateral Posterior Reversible Encephalopathy Syndrome Mimicking a Middle Cerebral Artery Infarction

Posterior reversible encephalopathy syndrome (PRES) is usually a reversible clinical and radiological entity associated with typical features on brain MR or CT imaging. However, the not-so-uncommon atypical radiological presentations of the condition are also present and they may go unrecognised as they are confused with other conditions. Here, we report a very rare case of atypical, unilateral PRES in a 49-year-old uremic, post-transplant female patient who presented with seizures. Initial MRI showed high-grade occlusion of the left middle cerebral artery (MCA) and lesions suggestive of subacute infarction in the ipsilateral frontotemporoparietal lobe. Patient symptoms had resolved a day after the onset without any specific treatment but early follow-up CT findings suggested hemorrhagic transformation. Follow-up MRI performed 2 years later showed complete disappearence of the lesions and persisting MCA occlusion.     

Transplantation of allogeneic peripheral blood stem cells mobilized by recombinant human granulocyte colony-stimulating factor [see comments]

Peripheral blood stem cells (PBSCs) are widely used in autologous transplantation because of ease of collection and rapid hematopoietic reconstitution. However, PBSCs have rarely been used for allogeneic transplantation because of concerns about donor toxicities from cytokine administration and the theoretical increased risk of graft- versus-host-disease (GVHD) from the large number of T cells infused. Eight patients with advanced malignancies received allogeneic PBSC transplants from genotypically HLA-identical sibling donors. All donors received 5 days of recombinant human granulocyte colony-stimulating factor (rhG-CSF; 16 micrograms/kg/day) subcutaneously and were leukapheresed for 2 days. After treatment of the patient with total body irradiation and cyclophosphamide (n = 7) or etoposide, thiotepa, and cyclophosphamide (n = 1), PBSCs were infused immediately after collection and without modification. All patients received cyclosporine and either methotrexate (n = 6) or prednisone (n = 2) for GVHD prophylaxis, rhG-CSF was well tolerated with mild bone pain requiring acetaminophen occurring in two donors. All patients engrafted and in seven hematopoietic recovery was rapid, with 500 neutrophils/microL achieved by day 18 and 20,000 platelets/microL by day 12. Complete donor engraftment was documented by Y chromosome analysis in all four sex-mismatched donor-recipient pairs tested and by DNA analysis in two sex-matched pairs. One patient died on day 18 of veno-occlusive disease of the liver with engraftment but before chromosome analysis could be performed (results are pending in 1 patient). A second patient died of fungal infection 78 days after transplant. Grade 2 acute GVHD occurred in two patients and grade 3 GVHD occurred in one patient. One patient is 301 days from transplant in remission with chronic GVHD; the remaining five patients are alive and disease free 67 to 112 days after transplantation. Preliminary results indicate that allogeneic PBSCs mobilized by rhG-CSF can provide rapid hematologic recovery without an appreciably greater incidence of acute GVHD than would be expected with marrow. Further follow-up is required to determine the incidence of chronic GVHD and any potential beneficial effects on relapse after transplant.