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M. Colevray VM. Tatard-Leitman S. Gouttard P. Douek L. Boussel 《Diagnostic and interventional imaging》2019,100(3):177-183
Introduction
The purpose of this study was to develop a convolutional neural network (CNN) to determine the extent of over-scanning in the Z-direction associated with lung computed tomography (CT) examinations.Materials and methods
The CT examinations of 250 patients were used to train the machine learning software and 100 were used to validate the results. Each lung CT examination was divided into cervical, lung, and abdominal areas by the CNN and 2 independent radiologists, and the length of each area was measured. Every part above or below the lung marks was labeled as over-scanning. The accuracy of the CNN was calculated after the training phase and agreement between CNN and radiologists was assessed using kappa statistics during the validation phase. After validation the software was used to estimate the length of each of the three areas and the total over-scanning in further 1000 patients.Results
An accuracy of 0.99 was found for the testing dataset and a very good agreement (kappa = 0.98) between the CNN and the radiologists’ evaluation was found for the validation dataset. Over-scanning was 22.8% with the CNN and 22.2% with the radiologists. The degree of over-scanning was 22.6% in 1000 lung CT examinations.Conclusion
Our study shows a substantial over estimation of the length of the area to be scanned during lung CT and thus an unnecessary patient's over-exposure to ionizing radiation. This over-scanning can be assessed easily, reliably and quickly using CNN. 相似文献44.
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Hematopoietic and fatty bone marrow distribution in the normal and ischemic hip: new observations with 1.5-T MR imaging 总被引:2,自引:0,他引:2
Mitchell DG; Rao VM; Dalinka M; Spritzer CE; Axel L; Gefter W; Kricun M; Steinberg ME; Kressel HY 《Radiology》1986,161(1):199-202
The conversion of hematopoietic to fatty marrow is known to correlate with physiologic decreases in intramedullary blood flow. To determine whether the chronology of conversion is altered in patients with hip ischemia, T1-weighted magnetic resonance (MR) images of the hips in 50 healthy people and 27 with documented avascular necrosis (AVN) were reviewed. The distribution of fatty (high-signal) versus hematopoietic (low-signal) marrow was noted with respect to age. All patients had fatty marrow in the femoral capital epiphysis and greater trochanter. Hematopoietic intertrochanteric marrow was seen in 95% (80 of 84) of femurs in control subjects less than 50 years old, but in only 12.5% (two of 16) of those in control subjects older than 50 years (P less than .005). Only 33% (19 of 57) of patients less than 50 years with AVN had predominantly hematopoietic intertrochanteric marrow (P less than .005). The early conversion to fatty marrow in most patients with AVN as depicted by MR imaging may be an effect of decreased vascularity of the proximal femur and may allow the identification of patients at increased risk for AVN. 相似文献
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Papillary endolymphatic sac tumors: CT, MR imaging, and angiographic findings in 20 patients 总被引:6,自引:0,他引:6