Q＆A：一种新的诊断放射科

StephenW

Q&A: A New Diagnosis for Radiologists
News | July 01, 2015 | Ultrasound
By Liza Haar

Q&A: A New Diagnosis for Radiologists

Last month, a consensus conference statement was published in Radiology by the Society of Radiologists in Ultrasound recommending that elastography techniques can be used to distinguish patients with no or minimal liver fibrosis and differentiate them from patients with severe fibrosis or cirrhosis. There were two significant outcomes from this recommendation: patients no longer need invasive liver biopsies to diagnose liver fibrosis, and radiologists will play a huge role in diagnosing diffuse liver disease, a part they did not play before.

Diagnostic Imaging spoke with lead author Richard Barr, MD, PhD, of the department of radiology, Northeastern Ohio Medical University in Rootstown, about what radiologists need to know about this technique.

Diagnostic Imaging: What’s some background on liver disease?

Barr: Liver disease is a substantial worldwide problem. It can be caused by several different ideologies: hepatitis B, hepatitis C, alcoholic liver disease, biliary cirrhosis, or nonalcoholic static liver disease. All of these ideologies tend to have one final pathway: they all cause chronic diffuse liver disease that leads to fibrosis and progresses into cirrhosis. It then becomes complicated cirrhosis, which has a relatively high risk of mortality.

The CDC estimates there are 240 million people worldwide with chronic hepatitis B, with an estimated 1.2 million in the United States.; hepatitis C has a prevalence of an estimated 2.7 million in the United States, and between 130 and 150 million worldwide.

In North America, diffuse fatty liver disease is the problem. Nonalcoholic fatty liver disease (NAFLD) has an estimated prevalence of 27%–34% of the US population, according to the Radiology study. Fatty liver disease, by itself, is not too much of an issue but it can progress to nonalcoholic steatohepatitis (NASH) in about 10%–20% of these patients. NASH is where the liver becomes fibrotic and will progress to cirrhosis. So we are talking about a huge population of patients with a diverse number of ideologies, but all with the end result of having cirrhosis.Richard Barr, MD, PhD

What are the challenges of diagnosis, management, and treatment of cirrhosis?

Fibrosis is often not picked up until the patient presents with cirrhosis. So we often don’t pick these patients up until far within the progression of the disease. There has been a significant change in the medical community because, at least now for hepatitis C and on the horizon for hepatitis B and NAFLD, there are treatments. Ideally, these treatments work better when we are picking up the diagnoses at a relatively early stage, so having a technique that would be able to diagnose the mild-to-moderate degrees of fibrosis would allow that patient to be treated appropriately sooner, or at least flagged to their doctors so they know to treat the patient and, again, the goal is not to let them get to the point of cirrhosis.

I think it’s important to note that in the past, the diagnosis was made by a liver biopsy, and obviously a liver biopsy is invasive; there is a small risk of death. It’s a painful procedure, and it really is not a good gold standard because these processes are very diffuse and a liver biopsy only samples a small portion of the liver. So it’s not the perfect test and the other problem is, as we are using these new treatments, we are finding that the treatments can reverse the degree of fibrosis. Ideally, we’d like to be able to monitor patients to see if these drugs are improving or decreasing the amount of fibrosis. The treatments are extremely expensive so being able to monitor the treatment is very important. Insurance companies are concerned about the high cost and making sure the treatment is given appropriately to the appropriate people.

This is where the elastography enters in. The elastography is an ultrasound technique where we use a stress, if you will. In the case of shear wave imaging, we use a low-frequency, high-energy pulse that in a sense “pushes” the liver. We use that ultrasound beam to push the liver and it creates shear waves. You can think of this like when you drop a stone in water, you get ripples, so the stone is that ARFI push pulse and the ripples are the shear waves, and the shear waves travel through tissue based on its stiffness: the softer the tissue, the slower the shear wave speed, the harder the tissue the faster the shear wave speed.

This technology could be used on multiple different organs, but it’s really a very good technique for the liver. We can do shear wave imaging, calculate out the shear wave speed through the liver, and then use that to identify the stiffness of the liver. There have been multiple studies done by vendors with various different techniques which show that this does work, the technology has been available in Europe and Asia for several years and I think it’s fair to say that the number of liver biopsies done in Europe and Asia have decreased dramatically.

The UK government actually put out a statement, the NICE guidelines, in which it recommends that liver biopsies not be done for diffuse liver disease and that elastography be the first method of choice. Liver biopsies would be reserved only if there is a specific reason why you would need to have a biopsy, for example the elastography does not match the clinical picture or additional information is needed that’s not provided by the elastography. In talking to my colleagues in Europe, liver biopsy for diffuse liver disease is becoming a rare procedure. This technology is newly approved in the United States and we suspect the same thing is going to happen here.

So imaging is new to the role of diagnosing liver disease?

In the past, the problem was conventional ultrasound, without elastography was very poor at determining if there was fibrosis in the liver. If you got to the point of cirrhosis, it was reasonably good at characterizing cirrhosis but again it was not very good at those lower levels. Ideally, it would be nice to 1) pick up those patients to make a diagnosis and intervene early to prevent it from progressing and 2) start them on a treatment if the etiology is treatable to reverse the fibrosis. Other things like MR are not that sensitive without elastography in determining these low to intermediate grades of fibrosis. It is reasonably good at picking up cirrhosis, but we would like to pick up these patients before they get to the end stage of cirrhosis. CT is awful for very low sensitivities, again, until you get to the very end stage of disease. So conventional imaging, CT, MR, ultrasound, are not very good at diagnosing the disease until it was in its very end stage.
f radiologists were already using imaging to diagnose focal disease, is diffuse liver disease a new area for them?

Definitely, and the European and Asian radiologists had the technology approved several years ago so they are a little bit ahead in incorporating this into their practice. I think in Europe and Asia, there are a lot of hepatologists and internal medicine doctors that do their own imaging so I think it’s being embraced there not only by the radiologists, but by other people that work with liver disease.

The imaging component is extremely important. As these patients go from mild to moderate to severe fibrosis and then to cirrhosis, as they progress along that continuum of disease, their risk for hepatocellular carcinoma (HCC) increases significantly. One of the things that I think most radiologists are very familiar with is patients that are diagnosed with cirrhosis especially from hepatitis C, get an ultrasound every six months to screen for hepatocellular carcinoma, so again we are doing the ultrasound to look for the complications of cirrhosis, but now with the elastography it’s allowing us to pick up the patients earlier.

I think right now radiologists are looking for gallstones, masses, and HCC in the average patient and we are doing screenings for HCCs in the patients that have known cirrhosis. But now with this technology, we are really adding additional clinical information that is very important. We can flag these patients that have these diseases that may not be known. There was a study in Romania that just screened everybody that came in for abdominal ultrasound for whatever cause, abdominal pain, abnormal liver function tests, etc. and they found that about 30% of the patients they screened that didn’t suspect to have cirrhosis actually had some degree of fibrosis that was significant and those patients needed follow up. So we are flagging these patients earlier so they can be provided appropriate treatment and hopefully prevent them from getting to cirrhosis.

There are other things that we can do now with imaging: we can add Doppler, we can evaluate to see if these patients move to cirrhosis, we can monitor the complications (verices, portal vein thrombosis, a big spleen). All of these things we can now pick up with ultrasound, so we can tell the clinician or hepatologist for the most part where this patient is on this continuum of being normal to mild to moderate to severe disease to cirrhosis and then decompensated cirrhosis.

That’s really critical information to the hepatologist for how to treat that patient and to provide follow up to see if the patient is getting worse or better with treatment.

We are finding patients that clinically are not suspected of having fibrosis, so their clinician would not have ordered a liver biopsy and we are picking up patients that would not have been flagged to get a liver biopsy until they were farther down the path of getting cirrhosis.

Has there been a lot of interest in elastography?

I think that there is a very high interest in this. I get calls and e-mails daily from people. One of the things about ultrasound elastography is the technique is very critical to give good results and there are a lot of people asking us for our protocols and how we’re doing this to make sure they get accurate results. I think there is a huge demand and interest in using this technology. There are also a huge number of patients that this technology would be helpful for. I think the technique is actually very easy and very simple; the problem is there are a lot of little pitfalls. In a sense, there is a learning curve to do this. It’s not a difficult thing to do, but there are a lot of possible errors in getting the measurement, so training on how to do the measurements exactly and where to do the measurement is really critical for getting good results.

How are radiologists trained?

Each vendor has the responsibility of making sure that if they sell the system to someone, that they get trained. We are in the process of developing a hands-on course with Philips that will allow physicians to get hands-on training. Sometimes it’s hard to train radiologists with just words on paper, so I think that education and training is very critical to get people on the right path. At this point, there really are no guidelines or standards as to how many cases someone should do to get used to the technique. I think people are struggling because as the technology comes out, there is greater demand for education so I suspect that there now will be organizations that will start offering hands-on courses for training.

What are the limitations?

There are some technical factors. The examination has to be approached through the ribs. We have to take the measurements at least 1.5 cm below the liver capsule and the probe has to be perpendicular to the liver capsule. We have to avoid blood vessels and any lesions when we are doing the measurement. Right now, I think most people are recommending you do 10 measurements in a similar location and then take the median of that measurement to get a more accurate measurement assessment. Then there are things like the standard deviation or the interquartile ratio, which is another way of looking at the standard deviation, and is important to make sure you have a good cluster of measurements around that median and that you aren’t getting measurements that are widely varied.

This technology looks at liver stiffness and if you’ve got chronic liver disease, then it’s really correlated with fibrosis. If you’ve got acute liver disease or chronic liver disease with acute exacerbation, then we are looking at stiffness from the fibrosis as well as the inflammation from the acute process. So in those situations, comparing it to liver enzymes to realize that those measurements are not providing you the fibrosis, but a combination of fibrosis and inflammation is another important factor that people need to be aware of. I think with larger patients, it is a little more difficult because the thicker the subcutaneous fat, the more likely it is that the sound waves are not getting through to generate the shear waves.

It seems to be a great diagnostic tool, what is its role in management of disease?

I think we are moving toward using it for management because the FDA has approved drugs for treatment of hepatitis C. I believe approval of drugs for hepatitis B are on the horizon, and there are going to be drugs approved for fatty liver disease. For all of these drugs, we need to know when is the appropriate time to use them because they are all very expensive. How do you select the patients that would qualify for this treatment? I believe that some insurance companies actually now for hepatitis C are requiring that the patient has to have a specific stiffness value or higher before they will approve payment for the treatment. I think we’re still working this out because it’s relatively new technology that you can monitor the patient with treatment to see if you’ve halted the disease, improved the disease so that the fibrosis is resolving, or to see if the patient is still progressing and you know that the treatment is not working.

The NICE document from the United Kingdom actually did a cost analysis and they figured there was a huge cost savings in using this technology versus doing liver biopsies.

I’ve talked to people on the CPT committee and there is an approval for a shear wave elastography measurement, but you can’t do imaging on the same day. So you could use that code, but then you could not bill for doing the imaging part and, in general, the reimbursement for doing the imaging is greater than the elastography, so my suspicion is, at this point, the radiologist would rather do an imaging study and add in the elastography using that nonreimbursable code. It doesn’t really make sense to have the patient come back on two different days to complete the exam, although you would think the CPT code committee would have considered that.

But there is a big push to now address the CPT code so that we can do both on the same day
- See more at: http://www.diagnosticimaging.com ... thash.M5lD9Fna.dpuf

StephenW

Q＆A：一种新的诊断放射科
新闻| 2015年7月1日|超声
由汪明荃哈尔

Q＆A：一种新的诊断放射科

上个月，一个共识会议声明发表在放射科放射科医师协会超声，建议弹性成像技术可以用来区分病人没有或很少肝纤维化和严重的患者肝纤维化或肝硬化区分它们。共有来自此推荐二显著的结果：患者不再需要侵入肝活检诊断肝纤维化和放射科医师在诊断弥漫性肝病，他们以前没有扮演一个角色发挥巨大的作用。

影像诊断与主要作者理查德·巴尔博士谈到放射科的东北俄亥俄医科大学Rootstown系，什么放射科医生需要了解这种技术的。

影像诊断：什么是肝病的背景？

巴尔：肝病是一个庞大的世界性难题。乙型肝炎，丙型肝炎，酒精性肝病，胆汁性肝硬化，酒精性或静态肝病：它可以由几个不同的意识形态引起。所有这些意识形态往往有一个最终途径：他们都引起慢性弥漫性肝病，导致纤维化和进展为肝硬化。然后，它变得复杂性肝硬化，其中有死亡的相对危险性高。

CDC估计有2.4亿人的全球慢性乙型肝炎患者，在美国估计有120万;丙型肝炎有在美国估计有270万人患病，和全世界的130和150亿美元。

在北美，弥漫性脂肪肝疾病的问题。非酒精性脂肪肝病（NAFLD）具有27％的美国人口的34％的患病率估计，根据该放射研究。脂肪肝疾病，其本身不是太大的问题，但它可在约10％的进展到非酒精性脂肪性肝炎（NASH），这些患者-20％。纳什所在的肝纤维化变，将发展为肝硬化。因此，我们正在谈论的患者意识形态的多样化数量庞大的人口，但都具有cirrhosis.Richard巴尔博士的最终结果

什么是诊断，管理和治疗肝硬化的挑战是什么？

纤维化往往不是拿起直到与肝硬化病人呈现。所以我们常常不接这些患者，直到远内的疾病的进展。出现了在医学界一个显著的变化，因为，至少现在为丙型肝炎和在地平线上为乙型肝炎和NAFLD，有治疗。理想的是，这些治疗更好地工作，当我们拿起诊断在相对早的阶段，所以具有一种技术，将能够诊断的轻度到中度程度的纤维化将允许该患者进行适当越早处理，或在至少标记，以他们的医生，让他们知道要治疗患者，并再次，我们的目标是不要让他们得到肝硬化的地步。

我认为需要注意的是，在以往的诊断是由肝活检做，显然肝活检是有创这一点很重要;有死亡的危险性小。这是一个痛苦的过程，它真的不是一个很好的黄金标准，因为这些过程是非常分散和肝活检标本只有肝的一小部分。因此，它不是完美的测试和另一个问题是，因为我们正在利用这些新的治疗方法，我们发现，该治疗可以逆转纤维化的程度。理想地，我们希望能够监视患者，以查看是否这些药物提高或降低纤维化的量。的治疗是极其昂贵，因此能够监测所述治疗是非常重要的。保险公司担心成本高，并确保治疗是适当给予适当的人。

这就是弹性进入了，这一弹性是我们使用一个压力，如果你愿意的超声技术。在横波成像的情况下，我们使用的意义上的“推”肝低频，高能量的脉冲。我们使用该超声波束推肝脏并创建横波。你可以认为这就像当你把在水中的石头，你得到的涟漪，从而使石材是ARFI推压脉冲和涟漪是横波，和横波通过组织基于其刚性出行：较软组织越慢横波速度，就越难组织越快横波速度。

该技术可用于在多个不同的器官，但它的确是一个非常好的技术肝脏。我们可以做的横波成像，计算出的横波速度通过肝脏，然后用它来确定肝脏的硬度。已经有与该结果表明，该做的工作的各种不同的技术厂商进行多项研究，该技术已连续几年被提供在欧洲和亚洲，我认为这是公平地说，在欧洲和亚洲进行肝活检的数量有显着下降。

英国政府竟拿出一份声明中，NICE指南，其中建议肝活检不能为弥漫性肝病和弹性是做选择的第一种方法。仅当有特殊原因，你为什么会需要有一个活检，例如弹性不匹配临床图片或需要附加信息，这不是所提供的弹性肝脏活组织检查将保留。在谈到我的同事在欧洲，肝活检为弥漫性肝病已成为一种罕见的程序。该技术是新批准在美国，我们怀疑同样的事情会发生在这里。

所以成像是新诊断肝脏疾病中的作用？

在过去，这个问题是传统的超声，没有，如果有纤维化肝脏弹性很差，在确定。如果你有肝硬化的点，它是在肝硬化特征相当不错的，但是这又不是很好，在这些较低的水平。理想情况下，这将是很好1）拿起这些患者做出诊断和早期干预，以防止其进展和2）启动它们在治疗，如果病因是治疗的逆转纤维化。像MR其他的事情都不是没有弹性的决定，这些低等级的中间纤维化敏感。正是在捡肝硬化相当不错的，但我们想拿起这些患者才得到肝硬化终末期。 CT可怕的是非常低的敏感性，再次，直到你得到疾病的最后阶段。所以常规成像，CT，MR，超声，都不是很擅长诊断疾病，直到它在它的结束阶段。
˚F放射科医生已经使用成像诊断疫源性疾病，是弥漫性肝病他们的一个新的领域？

肯定地说，与欧洲和亚洲有放射批准几年前，所以他们提前在将这个变成他们的实践一点点的技术。我认为在欧洲和亚洲，还有很多肝病和内科医师认为自己做的成像，所以我认为它正在拥抱那里不仅是由放射科医师，但与肝脏疾病工作的其他人。

所述成像部件是极为重要的。由于这些患者从轻度到中度到重度纤维化，然后为肝硬化，因为它们沿着病的那连续进展，他们的风险为肝细胞癌（HCC）显著增加。其中我认为最放射科医师都非常熟悉被诊断为肝硬化尤其是丙型肝炎患者是东西，得到一个超声波每半年筛查肝癌，所以我们再次做超声波去寻找的并发症肝硬化，但现在随着弹性它使我们的病人早期回暖。

我觉得现在放射科医生正在寻找胆结石，贴近群众，在肝癌病人的平均和我们正在做掩护在知道肝硬化患者肝癌。但是现在有了这一技术，我们真的增加额外的临床信息，这是非常重要的。我们可以旗这些患者具有这些疾病可能是未知的。有在罗马尼亚的一项研究，只是大家筛选中附带的腹部超声无论事业，腹痛，肝功能异常等，他们发现，大约30％的他们筛选了患者认为没有怀疑有肝硬化竟然出现了一定程度的纤维化，这是显著和需要的患者随访。所以我们举报这些早期的患者，使他们可以提供适当的治疗，并希望阻止他们获得肝硬化。

还有其他的事情，我们可以与成像现在这样：我们可以添加多普勒，我们可以评估，看看这些病人转移到肝硬化，我们可以监测并发症（verices，门静脉血栓形成，大脾）。所有这些事情，我们现在可以拿起超声波，所以我们可以告诉医生或肝病大部分，其中这名患者​​是在这个连续体是​​正常的轻度至中度至严重的疾病为肝硬化，然后肝硬化失代偿。

这是真正的关键信息的肝病如何来治疗病人，并提供跟进，看看病人越来越差或更好的配合治疗。

我们发现，临床上没有怀疑有纤维化的患者，所以他们的医生就不会下令肝活检，我们领了，不会被标记获得肝活检，直到他们越往下越来越肝硬化患者路径。

以前有很多的弹性兴趣？

我认为有这很高的兴趣。我每天收到电话和电子邮件的人。其中约超声弹性的东西是技术是非常重要的给好成绩，也有很多人问我们，我们的协议和如何我们这样做是为了确保他们得到准确的结果。我认为这是一个巨大的需求和兴趣在使用这种技术。也有巨大的患者，这种技术将是有益的数目。我认为该技术其实很容易，很简单;问题是有很多小陷阱。在某种意义上说，有一个学习曲线来做到这一点。这不是一个困难的事情，但也有很多在获得测量可能的错误，所以训练就怎么做测量准确，在哪里做的测量是获得了良好的效果真的很关键。

如何放射科医师培训？

每个厂商都有确保的责任，如果他们销售的系统的人，他们得到培训。我们正在开发一个动手的课程与飞利浦，将允许医生拿到手的培训过程。有时候很难放射科医师培训与在纸上空谈，所以我认为教育和培训是非常重要的，让人们在正确的道路上。在这一点上，真的有没有指引或标准，很多情况下，一个人应该怎么做才能习惯的方法。我觉得人都在努力，因为随着技术的问世，对于教育的需求较大，所以我怀疑，现在将有机构，将开始提供手把手的培训课程。

有什么限制？

还有一些技术因素。考试必须通过肋骨接近。我们必须采取的测量为至少1.5厘米以下的肝包膜和探针具有以垂直于肝包膜。我们必须避免血管和任何病变，当我们正在做测量。现在，我想大多数人都推荐你做10个测量类似的位置，然后采取测量的平均以获得更精确​​的测量评估。再就是像标准偏差或四分的比例，这是观察的标准偏差的另一种方式，而且重要的是要确保你有周围的平均测量一个很好的集群，你没有得到的测量是极大地改变。

该技术着眼于肝脏硬度，如果你有慢性肝脏疾病，那么它真的与相关的纤维化。如果你有严重的肝脏疾病或慢性肝脏疾病的急性发作期，则我们从纤维化以及由急性过程中的炎症看着僵硬。因此，在这些情况下，比较到肝酶来实现，这些测量不提供你的纤维化，但纤维化和炎症的组合是，人们需要知道的另一个重要因素。我认为有较大的患者，这是有点困难，因为较厚的皮下脂肪，就越有可能的是，声波都没有获得通过，以产生切变波。

这似乎是一个伟大的诊断工具，什么是它在疾病管理中的作用？

我认为我们正在朝着使用它的管理，因为FDA已经批准的药物用于治疗丙型肝炎的，我相信药物对乙肝批准在地平线上，并有将要被批准用于脂肪性肝病的药物。对于所有这些药物，我们需要知道什么时候是适当的时候使用他们，因为他们都是非常昂贵的。你如何选择有资格获得这种治疗病人？我认为，一些保险公司实际上现在对于丙型肝炎都要求病人必须有一个特定的刚度值以上之前，他们将批准支付治疗。我想我们仍在努力这一点，因为它是相对较新的技术，可以监测病人配合治疗，看看你是否已经停止了这种疾病，改善病情，以使纤维化解决，还是看患者是否仍取得进展，你知道，治疗不工作。

来自英国NICE的文件实际上是做了成本分析，他们想出有一个巨大的节约利用这一技术对做肝活检成本。

我已经说过了人们对CPT委员会，有一个批准一个横波弹性测量，但你不能做成像在同一天。所以，你可以使用该代码，但你不能法案做成像部分，在一般情况下，报销做成像大于弹性，所以我怀疑是，在这一点上，放射科医生宁愿做一个影像学研究并添加使用无偿代码的弹性。它并没有真正意义的有病人回来两个不同天完成考试，但你会觉得CPT代码委员会会考虑这一点。

但是有一个很大的推动，以解决现在的CPT代码，使我们可以在同一天既做
- 在查看更多： http://www.diagnosticimaging.com ... thash.M5lD9Fna.dpuf

9病成医

跟现在临床使用的肝弹性检测设备是一回事吗？

StephenW

回复 9病成医 的帖子

英国放射科医师协会建议弹性成像(Fibroscan)用来区分病人没有或很少肝纤维化和严重的肝纤维化或肝硬化, 不再需要肝活检.