Comparison of Accuracy of One-Use Methods for Calculating Fractional Flow Reserve by Intravascular Optical Coherence Tomography to That Determined by the Pressure-Wire Method.

Although the identification of the hemodynamic significance of coronary lesions becomes important for revascularization strategy, the potential role of 3-dimensional high-resolution intracoronary optical coherence tomography (OCT) for predicting functional significance of coronary lesions remains unclear. We assessed the diagnostic performance of 2 computational approaches for deriving fractional flow reserve (FFR) from intravascular OCT images. We developed 2 methods to derive FFR-OCT by AFD (FFR-OCTAFD) and FFR-OCT by CFD (FFR-OCTCFD). Among 217 eligible patients between 2011 and 2014, 104 were included for data analysis (9 for derivation, 95 for validation). Luminal geometries from 3-dimensional OCT were used for both FFR-OCTAFD and FFR-OCTCFD calculations. The analytical fluid dynamics method calculated FFR from the blood flow resistance estimated using Poiseuille's law. For computational fluid dynamics, we numerically solved the Navier-Stokes equation in a steady-state flow with the distal porous media model for the capillary vessels. We examined the diagnostic performance of FFR-OCTAFD and FFR-OCTCFD compared with the pressure-wire measured FFR. The accuracy, sensitivity, specificity, PPV, and NPV were 86%, 65%, 94%, 81%, and 88% for FFR-OCTAFD and 86%, 73%, 91%, 76%, and 90% for FFR-OCTCFD. The area under the curve of the receiver-operating characteristic curve was 0.88 for FFR-OCTAFD and 0.86 for FFR-OCTCFD. FFR-OCTAFD and FFR-OCTCFD showed a strong linear correlation with the measured FFR (r = 0.631; p <0.001, r = 0.655; p <0.001, respectively). FFR derived from high-resolution volumetric OCT images showed high diagnostic performance for the detection of coronary ischemia. In conclusion, OCT-derived FFR may be useful for guiding the management of coronary artery disease.

[Clinicopathologic and immunophenotypic analysis of myeloid sarcoma].

OBJECTIVE: To study the clinicopathologic features of myeloid sarcoma and to evaluate the role of immunohistochemical study in diagnosis of this entity. METHODS: Eighty-two cases of myeloid sarcoma were retrieved from the archives of Department of Pathology, West China Hospital of Sichuan University during the period from January, 1990 to February, 2005. The morphologic features were reviewed and classified according to the 2001 WHO classification for hematopoietic and lymphoid tissue tumors. Immunohistochemical study using a panel of 11 antibodies was performed on 73 cases. The survival data were collected and analyzed by SPSS 10.0. RESULTS: The median age of patients was 35.5 years. The male-to-female ratio was 1.4:1. The sites of occurrence included lymph node (43.1%), skin (16.7%), nose (7.8%), soft tissue (7.8%) and bone (6.9%). Fifty-one cases (62.2%) represented myeloid sarcoma associated with an underlying myeloproliferative disorder and 25 cases (30.5%) represented solitary myeloid sarcoma. As for the morphology, 79 cases (96.3%) were granulocytic sarcoma, including 41 cases (51.9%) blastic type, 25 cases (31.6%) immature type and 13 cases (16.5%) differentiated type. The other 3 cases (3.7%) were monoblastic sarcoma. Immature eosinophils were found in 51 cases (64.6%) of granulocytic sarcoma, among which 13 cases (31.7%) were of blastic type. Immunohistochemical study showed that 95.9% cases (70/73) were positive for myeloperoxidase, 95.5% (63/66) for lysozyme, 95.2% (60/63) for CD68 (KP1), 90.8% (59/65) for leukocyte common antigen, 85.7% (54/63) for CD43, 77.8% (49/63) for CD117, 58.7% (37/63) for CD99, 54.0% (34/63) for CD15, 22.2% (14/63) for CD34, and 4.7% (3/64) for CD68 (PG-M1). Proliferation index, as demonstrated by Ki-67 positivity, was 0.49+/-0.22. Follow-up data was obtained in 59 of the 82 patients. The two- and five-year survival rates were 36.1% and 17.3% respectively. No significant prognostic factors were found in the survival analysis. CONCLUSIONS: Myeloid sarcoma may precede, develop in a background of myeloproliferative disorder or even after remission of the disease. The presence of immature eosinophils is an important morphologic clue and immunohistochemical study plays an essential role in arriving at a correct diagnosis. Immunopositivity for myeloperoxidase is specific for granulocytic differentiation, while CD68 (PG-M1)-positivity suggests monocytic differentiation. Detailed clinicopathologic correlation is also helpful.