Tổng số lượt xem trang

Chủ Nhật, 2 tháng 9, 2018

Handheld ultrasound + CADx helps triage breast masses


By Kate Madden Yee, AuntMinnie.com staff writer
August 31, 2018 -- Researchers successfully used a combination of handheld ultrasound and computer-aided diagnosis (CADx) software to triage women in Mexico who had palpable breast masses. They believe the combination is good news for women who may not have access to screening mammography, according to an article published online August 29 in the Journal of Global Oncology.
"[Our] results open up the possibility of implementing practical, cost-effective triage of palpable breast lumps, ensuring that scarce resources can be dedicated to suspicious lesions requiring further workup," wrote a team led by Dr. Susan Love of the Dr. Susan Love Research Foundation in Encino, CA.
In low- to middle-income countries, 23% of new breast cancer cases occur among women ages 15 to 49 years, compared with 10% of new breast cancer cases in high-income countries. Because screening mammography is not necessarily available, women often present with palpable breast lumps; although most of these masses are benign, it's important to determine which of them need further evaluation, Love and colleagues wrote.
In these situations, portable ultrasound is often available, but image interpretation has traditionally been performed by radiologists or breast surgeons -- who may be in short supply.
"At [our study] site, the average wait for a diagnostic ultrasound is nine months because of limited available trained radiologists," the researchers wrote. "Many of the participants traveled up to six hours by bus to participate in this study, corroborating the need for a simple accessible local means of triage."
For the study, Love's group trained three nonradiologist healthcare workers in Jalisco, Mexico, to determine whether they could use ultrasound to acquire images of sufficient quality for accurate analysis by CADx software. The workers were a first-year medical student, a surgical nurse, and a gynecologic intern who used a portable ultrasound scanner (Vscan, GE Healthcare) to acquire orthogonal views of 32 breast masses in 32 women.
The images were analyzed using what the researchers call "triage CADx," an artificial intelligence-based CADx program for ultrasound that is based on convolutional neural networks. CAD results were then compared with radiologist readings.
Among the 32 masses, two were malignant. Nonradiologist healthcare staff was able to acquire adequate images, Love and colleagues found. In addition, triage by the software was as accurate as radiologist assessment of the masses, with 100% sensitivity and specificity.
The results suggest a way to make use of limited breast care resources in low- to middle-income countries.
"This study demonstrates that first-level healthcare workers are capable of acquiring images with a portable ultrasound machine comparable to those of a trained radiologist," the group concluded.

Thứ Bảy, 1 tháng 9, 2018

ULTRASOUND and FETAL NERVOUS SYSTEM LESIONS

https://www.e-ultrasonography.org/journal/view.php?number=214

Abstract

Central nervous system (CNS) malformations play a role in all fetal malformations. Ultrasonography (US) is the best screening method for identifying fetal CNS malformations. A good echographic study depends on several factors, such as positioning, fetal mobility and growth, the volume of amniotic fluid, the position of the placenta, the maternal wall, the quality of the apparatus, and the sonographer’s experience. Although US is the modality of choice for routine prenatal follow-up because of its low cost, wide availability, safety, good sensitivity, and real-time capability, magnetic resonance imaging (MRI) is promising for the morphological evaluation of fetuses that otherwise would not be appropriately evaluated using US. The aim of this article is to present correlations of fetal MRI findings with US findings for the major CNS malformations.


Introduction

Fetal imaging evaluation has improved over the years. Faced with more complex diagnoses, magnetic resonance imaging (MRI) has become widely used as an important complement to prenatal ultrasonography (US). Due to its higher contrast resolution than US, fetal MRI allows normal versus abnormal tissue to be better differentiated, providing detailed imaging information on fetal structures, particularly the brain. To date, fetal MRI has been shown to play an important role in the evaluation of structural brain development and in the assessment of abnormalities suspected on US [1,2]. Moreover, the use of fetal MRI has been shown to help in counseling parents during pregnancy and in discussions about treatment [1].
As the indications for fetal brain MRI are mainly based on abnormal US findings, fetal MRI is usually performed during the second half of gestation, from 18 to 20 weeks onward. After that point, the utility of prenatal US is limited due to decreased amniotic fluid volume, fetal positioning, and acoustic shadowing from the ossifying calvaria. For these reasons, MRI represents an important modality for morphologic evaluation of the fetal brain in the second half of gestation [1,3].

The most common indications for imaging the fetal brain are briefly discussed below, and include anencephaly, ventriculomegaly, corpus callosum agenesis, holoprosencephaly, hydranencephaly, schizencephaly, porencephaly, microcephaly, Chiari malformation, iniencephaly, the Dandy-Walker malformation, vein of Galen malformations, tuberous sclerosis, and encephalocele.
Nota:

anencephaly= vô não
ventriculomegaly= phì đại não thất
corpus callosum agenesis = teo thể chai
holoprosencephaly= tiền não hoàn toàn do không có phân cách vỏ não, (gồm alobar, semilobar và lobar forms).
hydranencephaly = não úng thủy toàn bộ
schizencephaly= não chẻ (nứt)
porencephaly= rỗ não, thông não thất bên ra bề mặt não
microcephaly= não nhỏ
Chiari malformation
iniencephaly = dị dạng não củ hành
dị dạng Dandy-Walker
dị dạng tĩnh  mạch Galen
xơ cứng củ
encephalocele= thoát vị não