Evaluation of kidney oxygen bioavailability in acute renal failure by blood oxygen level dependent magnetic resonance imaging / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To assess the kidney oxygen bioavailability in acute renal failure using blood oxygen level dependent (BOLD) magnetic resonance (MR) imaging.</p><p><b>METHODS</b>Twenty-one patients with acute renal failure, including 18 patients with oliguric renal failure, 1 nonoliguric acute renal failure and 2 functional renal failure were enrolled in the study; 20 healthy subjects served as controls. All subjects received renal functional MR examination. BOLD MR imaging with 16 gradient-recalled-echoes on a 1.5-T scanner were performed. R2(*)(1/sec) values of the cortex and medulla and R2(*) ratio of the medulla to cortex (R2(*) ratio of M/C) of the renal were recorded respectively.</p><p><b>RESULTS</b>The R2(*) values of the medulla was higher than those of the cortex in controls (17.64 +/-1.86/sec vs 13.73 +/-0.49/sec, P<0.00). The R2(*) ratio of M/C in controls was 1.28 +/-0.06. The R2(*) values of the medulla (13.31 +/-4.28/sec) and cortex (12.25 +/-2.41/sec) and the R2(* ) ratio of M/C (1.01 +/-0.25) in oliguric renal failure were lower than those in controls (P <0.05). Patients with functional renal failure and nonoliguric acute renal failure had higher R2(*) values in cortex and medulla and higher R2(*) ratio of M/C than those of controls.</p><p><b>CONCLUSION</b>BOLD MRI demonstrates that decreased R2(*) values of cortex and medulla suggest lower oxygen bioavailability in acute renal failure and decreased R2(*)ratio of M/C suggests the disappearance of a steep cortico-medullary gradient of oxygen.</p>

Value of diffusion-weighted MR imaging in diagnosis of acute rejection after renal transplantation / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the feasibility of MR diffusion-weighted imaging (DWI) in diagnosis of acute rejection after renal transplantation.</p><p><b>METHODS</b>Sixty-nine patients who underwent renal transplantation were enrolled in the study. According to the clinical features and renal biopsy, 26 patients were designated in rejection group and 43 in non-rejection group. Patients in non-rejection group underwent MR DWI scan at 2 to 3 weeks after operation, and those in rejection group underwent scan at 5 d before or after renal biopsy. Then the apparent diffusion coefficient (ADC) values of transplanted kidneys were measured with high diffusion sensitivity gradient factors (b values).</p><p><b>RESULTS</b>Patients with acute rejection had significantly lower ADC (P <0.04) than non-rejection patients with all the different b values (b=200, 400, 600, 800, 1,000 s/mm(2)). The ROC curves showed that sensitivity and specificity were best when b value was 800 s/mm(2).</p><p><b>CONCLUSION</b>DWI is a potential and reliable non-invasive method for the diagnosis of the acute rejection after renal transplantation.</p>

Correlation between pathology and imaging characteristics of hepatic agiomyolipoma / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To discuss CT and MRI characteristics of hepatic angiomyolipoma based on pathological findings.</p><p><b>METHODS</b>The CT and MRI appearances with related pathohistological subtypes of 11 hepatic angiomyolipomas from 10 patients were retrospectively analyzed.</p><p><b>RESULT</b>Ten patients with hepatic angiomyolipomas were subcategorized into lipomatous (3 cases), angiomatous (1 case), myomatous (1 case) and mixed (5 cases) subtypes. Lesions of the lipomatous type were mainly composed of adipocytes which could be easily recognized on both CT and MRI. Abnormal vessels were commonly seen in the angiomatous lesions, which showed pronounced enhancement in the early arterial phase and remained higher than or isodense with the normal parenchyma in the portal phase. The myomatous type was predominantly composed of leiomyoid cells mixed with small amount of adipocytes. The mixed type was the most frequent,evenly comprising sheets of epithelioid muscle cells admixed with islands of adipocytes and abnormal vessels, and showing homogeneously low density on plain CT and low signal intensity on T1-weighted,intermediately high signal intensity on T2-weighted MRI scans. On dynamic study with both CT and MRI, the mixed type exhibited obvious enhancement, which retained to some degree during the portal phase.</p><p><b>CONCLUSION</b>The discrete CT and MRI appearances of hepatic angiomyolipomas with different pathological subtypes depend on the components of the tumor.</p>

Imaging diagnosis of abdominal solitary fibrous tumor / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the imaging characteristics of abdominal solitary fibrous tumor (SFT) with its pathological features.</p><p><b>METHODS</b>Six cases of abdominal solitary fibrous tumors were studied using X-ray, CT, MRI examination as well as histopathological and immunohistochemical techniques.</p><p><b>RESULT</b>Contrast enhanced CT showed early intense enhancement as a result of the rich vascularization. On MRI the parenchyma of the tumors showed hypointensity on T1WI, T2WI and some tumors might manifest areas of hyperintensity on T2WI due to myxoid degeneration or hemorrhage. Microscopically, SFT was composed of spindle cells with various patterns and these spindle cells were CD34 positive on immunohistochemistry.</p><p><b>CONCLUSION</b>SFT is a soft tissue tumor originating from mesenchyma. Abdominal SFT shows variable appearance and enhancement pattern on CT and MRI according to tumor cells distribution and myxoid degeneration or hemorrhage within the tumor pathologically.</p>

Correlation between pathology and image characteristics of retroperitoneal liposarcoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation between the pathological and image features of different subtypes of retroperitoneal liposarcoma.</p><p><b>METHODS</b>Pathological and image characteristics of 21 retroperitoneal liposarcomas were retrospectively analyzed comparing their different histopathological subtypes.</p><p><b>RESULTS</b>This series consisted of 11 well-differentiated, 4 myxoid, 3 round-cell, 2 pleomorphic and 1 dedifferentiated liposarcoma. Well-differentiated liposarcomas were predominantly composed of lipoma-like and sclerosing components. On CT and MRI image, the attenuation and signal intensity of lipoma-like components resembled those of fat, whereas the signal intensity of sclerosing components was similar to those of muscle. Unenhanced CT image of the myxoid subtype showed density resembling that of water. On contrast-enhanced CT image, it showed gradual reticular or sheet-like enhancement. The CT and MRI image appearance of the round cell and pleomorphic subtypes resembled those of nonfatty soft tissue masses with foci of necrosis. The dedifferentiated liposarcoma showed the image feature of a well-differentiated component clearing enhanced soft tissue mass.</p><p><b>CONCLUSION</b>Different subtypes of retroperitoneal liposarcoma show different CT and MRI features relating to their major histologic components. A good understanding of the relation between their radiological and pathological features is helpful to arrive at a correct diagnosis for retroperitoneal liposarcoma.</p>