tag:blogger.com,1999:blog-37215995682223349052012-02-16T05:57:44.050-08:00of shadowsDanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.comBlogger521100tag:blogger.com,1999:blog-3721599568222334905.post-33075877873567852222011-12-21T21:31:00.001-08:002011-12-21T21:35:11.889-08:00

examining CMR references for LVEDV reveals interesting differences; doubt is cast upon the practice of generating z-scores for indexed values I have been tinkering with z-scores for cardiac MRI and I thought it might be interesting to compare a couple of references for LV end-diastolic volume (I always think this stuff is interesting): Alfakih et al., (JMRI, 2003) Buechel et al. (JCMR,

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-41894421356058661672011-10-29T21:25:00.000-07:002011-10-29T21:25:31.514-07:00

A spreadsheet comparing different BSA calculations on various patients-- and the resulting BSA-adjusted z-scores-- reveals negligible differences. Can we compare z-scores from various references when the methods for calculating BSA are different? How? If a given group of z-score equations are BSA adjusted, and a given patient has a different BSA depending on the BSA formula, how do you

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-11795252359244979832011-06-26T10:22:00.000-07:002011-06-26T10:39:06.691-07:00

Calculate PA pressure using pulmonary artery Doppler acceleration time.PA Acceleration Time (msec): Estimated PA Pressure:   MethodsDoppler interrogation of the pulmonary artery was performed in the parasternal short axis view, with the pulsed-wave sample volume placed at the annulus of the pulmonary valve. The acceleration time was defined as the interval between the onset of systolic

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-54963094332467495432011-03-19T23:40:00.001-07:002011-03-19T23:49:08.737-07:00

A little decoration for the aortic root z-score calculator: charts. Charts add a little ‘sugar’ to the reporting of the aortic root z-scores, by adding an important visual element to the situation. I have tinkered with charts for the aortic root before, with a few ‘smack-down’ pages, but this is the first large-scale incorporation of the charts with the z-score calculator (well, that’s not

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-75747024547018839952011-03-13T09:41:00.001-07:002011-03-13T14:46:32.939-07:00

Two new z-score calculators on Parameterz.com plus a paradigm shift or two First, the z-score calculators: LV End-Diastolic Volume z-scores, using the 5/6 A-L method A consolidated Aortic Root z-score calculator The paradigm shifts are these: All calculations are now server-side, using Python The Aortic Root calculator is a prototype for combining all available references into

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-4815724072176357782011-01-20T23:07:00.001-08:002011-01-20T23:07:08.749-08:00

A look at evolving benchmarks for pediatric cardiac reference data I read with some interest the article Optimal Normative Pediatric Cardiac Structure Dimensions for Clinical Use and was amused to see an off-hand reference to Parameter(z): Pettersen et al’s paper does not specify which BSA formula was utilized; however, the cardiac dimensions they measured have been normalized using both

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-37422926692374600732011-01-12T18:10:00.001-08:002011-01-12T20:46:37.620-08:00

The January issue of JASE holds this gem of a manuscript: New equations and a critical appraisal of coronary artery Z scores in healthy children. Dallaire F, Dahdah N. J Am Soc Echocardiogr. 2011 Jan;24(1):60-74. Epub 2010 Nov 13. The title couldn’t be any more fitting-- it is a must-read for anyone interested in the matter of z-scores for pediatric cardiology.The authors

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-68443489318929625172010-12-27T08:53:00.000-08:002010-12-27T08:53:00.175-08:00

Using the echocardiographically obtained parameters of vena contracta width and abdominal aorta flow VTI’s to estimate the severity of aortic insufficiency. The recent article An echocardiographic model predicting severity of aortic regurgitation in congenital heart disease presents an interesting model for predicting aortic regurgitation severity. Using MRI as their gold standard, the authors

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-81726375519109529292010-05-03T23:09:00.001-07:002010-05-03T23:09:13.714-07:00

A mashup of Google technologies to create a free, simple, open-access database. The upcoming ASE Guidelines ”Recommendations for Quantification Methods During the Performance of a Pediatric Echocardiogram”, is intended to serve as The Standard for measurement techniques in pediatric echo. Getting everyone on the same page as far as making measurements is a prerequisite for moving forward with

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-36322863785995844852010-04-21T13:55:00.001-07:002010-04-21T14:00:44.634-07:00

Boston Children’s versus Children’s National Medical Center for a “giant” knockout When the Children’s National (CNMC) coronary artery z-score equations were published in 2008, I briefly compared them to the 2007 Boston data and noted their similarities. In my opinion, the manner in which the CNMC equations handle the “standard deviation” makes these incompatible with some newly proposed cutoffs

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-63488715005209926442010-03-27T20:06:00.001-07:002010-03-27T20:06:51.622-07:00

A new z-score calculator for the aortic root (annulus, sinuses of valsalva, sinotubular junction, ascending aorta) is now available at ParameterZ.com. In addition to the online z-score calculator I have also created: an example calculation walk-through a sinuses of valsalva z-score comparison an ascending aorta z-score comparison Caveats A couple of things worth mentioning

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-37239825603846385632010-03-14T18:01:00.001-07:002010-03-14T18:03:32.030-07:00

A recent article includes a cameo appearance by none other than ParameterZ.com: Method 5: z-scores of LVM indexed for height2.7 were calculated as described in a recent publication which is accessed using an online calculator at http://parameterz.blogspot.com/2008/09/lv-mass-z-scores.html (accessed 6 April 2009). Incidence of left ventricular hypertrophy in children with kidney disease:

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-37741777135755886632010-02-07T08:32:00.001-08:002010-02-07T08:33:05.423-08:00

Searchable, sortable normal Doppler values for aortic and mitral valve replacements. Around the echo lab we are politely referring to the recent JASE Guideline Recommendations for Evaluation of Prosthetic Valves as "the Beast". Both for the size of the article (40 pages!) as well as the onus of now having to perform a more exhaustive evaluation on our valve replacement patients. We were used to

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-89748847165258949982010-01-03T07:42:00.001-08:002010-02-07T06:57:47.795-08:00

New fetal cardiac z-score equations from William Beaumont Hospital; new online calculator at OBSONO.orgFollowing up on their abstract from earlier this year, the group at William Beaumont Hospital in Royal Oak, Michigan produced what turns out to be the largest cross-sectional study of normative data for fetal cardiac measurements of all time:Fetal echocardiography: z-score reference ranges for a

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-70316149818487328982009-11-29T11:39:00.001-08:002009-11-29T11:39:16.322-08:00

Z-Scores for RV systolic function. Using data published in the June 2009 JASE, this calculator determines the age-adjusted Tricuspid Annular Plane Systolic Excursion (TAPSE) z-scores: Notes: For the purpose of calculating the z-score, I used the published mean and "-3SD" lower limit to calculate each SD ([mean – lower limit] / 3)- which is a little bit off-label. That is, the standard

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-71185307167012896532009-11-11T07:19:00.001-08:002009-11-11T07:19:23.544-08:00

some offhand observations about the treatment of skewness in pediatric echo reference data. Skewness: 1. asymmetry in a frequency distribution. 2. a measure of such asymmetry. Underlying the use of z-scores is an assumption about the symmetric nature of the distribution: the use of "Z" is because the normal distribution is also known as the "Z distribution". However, as noted elsewhere[1, 2]

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-66322330309760518822009-11-02T18:23:00.001-08:002009-11-02T18:23:25.958-08:00

Seems like I spent most of the month of October thinking about fetal echos in one form or another. Apart from the earlier release of the Fetal Echo Z-Scores: Femur Length calculator, I also developed a couple of "helper" routines: A calculator to cross-check the femur length against the EGA derived from dates. Also Gives reference values for fetal thoracic circumference: Fetal Biometry

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-69492457238517006492009-10-13T18:23:00.001-07:002009-10-13T18:23:05.711-07:00

Cardiac valve, chamber, and arch z-scores based on femur length; predicted LMP/EDD/EGA; LV/RV size discrepancy ratios. This update provides the following functionality: Fetal cardiac z-scores calculated from femur length According to the source article, each of the independent variables (EGA, FL, BPD) had similar performance, with the regressions based on femur length being slightly superior.

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-7808780809843644652009-08-02T10:24:00.001-07:002009-08-04T16:58:10.227-07:00

Calculate z-scores and normal ranges for 80+ echocardiographic measures including m-mode, 2D, and Doppler; generate z-score graphs.While browsing, I more-or-less stumbled upon a great website put together by the good folks at Children's Mercy Hospital (Kansas City, MO). The depth and breadth of measurements is astonishing, as is the number of observations from which the reference values are

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-49242799907974377412009-06-04T16:27:00.001-07:002009-09-09T20:13:21.925-07:00

I am starting to think I should change the tagline for this blog to: more questions than answersI am in the midst of building another smackdown calculator: I hope that it use is self-explanatory and that it requires no introduction- because I am now out of time (heading out to the ASE meeting!). This is still a 'work in progress' (I seem to have lots of these). Upon my return from the

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-35009727857000352592009-04-18T12:01:00.001-07:002009-04-20T21:34:37.007-07:00

Calculators for Critical Aortic Stenosis: Rhodes Score, Discriminant Score, and CHSS Survival BenefitIn a previous post I presented my first version of the Discriminant Score calculator. Since then, we (sonographers) still get asked to calculate a Rhodes Score (this score has achieved virtual Brand Name recognition at this point) for patients with what appear to be borderline anatomy- even though

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-86341584257020544112009-03-22T20:20:00.001-07:002009-03-22T20:20:11.786-07:00

I have been working on different visualizations of the data we see and use every day in the pediatric echo lab. Consider the following hypothetical patient data:   t0 t1 t2 t3 Height(cm): 55 58 65 75 Weight(kg): 3.5 3.9 4.5 7 LMCA (mm): 2.9

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-31262128108705011842009-03-12T19:12:00.001-07:002009-03-12T19:12:58.546-07:00

"...now give back the green"  billing is not collecting elevation plane

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-82940486371770450122009-02-18T18:36:00.001-08:002009-02-18T18:41:57.714-08:00

"Because." This was the explanation I was given, very early in my introduction to "digital echo", about why we record These Views in This Order. At the time, I was coming from a lab that did things proper: starting with the subcostal views. The only sense this new "parasternal images 1st" protocol made was that it supposedly made reading the studies easier. How convenient. For you. Who

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-27997772342069940012009-01-13T19:28:00.001-08:002009-01-13T19:59:42.233-08:00

Described as "one of the fundamental tasks of scientific inquiry", model selection could consume the better part of an afternoon and an important part of one's budgeted time with a statistician. Enter ZunZun.com. If you're looking for quality curve fitting and surface fitting, this is the site for you! The power law applied by Sable et al. in their description of coronary artery reference

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-47415918406440884652008-12-31T06:16:00.001-08:002009-01-01T16:27:18.618-08:00

I much prefer the 'ellipse tool' to the default method of tracing borders with the trackball. Plus, it is quick, pretty, and is more consistent with the principle behind the calculation. Height (cm): Epicardial Area (cm2): Endocardial Area (cm2): LV Long Axis (cm):   LV Mass (g): Z-Score:   Notes: Measure at end diastole (End diastole can be

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-21678095029246420082008-12-14T21:00:00.001-08:002008-12-14T21:00:52.463-08:00

The folks over at Children's National Medical Center, Washington, D.C. (CNMC) have fired up their digital echo database: in a four month period, they sorted through over 400 eligible normal echos, and served up the largest analysis of normal coronary artery dimensions to date. Their approach to the data analysis included explorations of the independent variables of BSA and height (and height,

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-3532351236183214262008-12-07T10:50:00.000-08:002008-12-07T15:20:18.496-08:00

A z-score calculator for the ascending aorta (AAO), based on this article, is now available at ParameterZ. The source article is relatively recent (2006) and confirms my own experience: z-score data for the ascending aorta are hard to find.We provide for the first time a published regression equation for calculation based on BSA of the expected size of the ascending aorta in children, which

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-54469975516118151822008-11-21T13:13:00.001-08:002009-11-11T07:22:25.876-08:00

After tackling the z-score:percentile issue, I thought it might be interesting to graph how different z-score equations look in this light. Here is what I derived as the cumulative density function for the aortic valve z-score (1.0 m2; male) using data published from Boston, Wessex, Cincinnati, and Detroit: I think that because I have explained z-scores to our students and fellows so many

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-72419243654746451242008-11-01T11:07:00.001-07:002008-11-02T07:41:29.711-08:00

I recently revisited the idea of calculating percentiles in addition to z-scores for the pediatric echo z-score calculators. The cumulative percent is shown along with the z-score in the following image:   Since the relationship between z-score and percentile is constant, it seemed to me of no great benefit to add the percentile information. However, I now feel that percentiles convey

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-55862076891245650252008-10-22T12:18:00.001-07:002008-10-25T13:30:57.731-07:00

Having trolled the literature in an effort to consume and digest what has already been published in the name of "Pediatric Echo Normal Values" and "Pediatric Echo Reference Values" I have come to the conclusion that what I really wanted was this: a common collection of normative data, from which we could all draw our own conclusions. That doesn't exist. Yet. There now appears to be growing and

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-84984538912462076662008-10-03T21:39:00.001-07:002008-10-03T22:09:07.624-07:00

Based on work from Boston Children's Hospital, this calculator determines the aortic valve z-score and the discriminant score — for "predicting which neonates with AS are suitable for biventricular repair and which are better served by single ventricle management." Discriminant Score Calculator Height (cm): Weight (kg):

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-84439183728069431332008-09-25T20:42:00.001-07:002008-10-27T20:00:58.717-07:00

While I am not going to rush out to get the first web-enabled washing machine, I am keen on Google's vision of the future, and commonality of scientific data: Scientific measurements and experimental results will be blogged and automatically entered into common data archives to facilitate the distribution, sharing and reproduction of experimental results. I have not yet given up on the idea of

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-37410962785311189122008-07-23T22:38:00.000-07:002008-10-20T07:52:04.780-07:00

The January 2008 issue of JASE includes the article: Routine Adjustment of Doppler Echocardiographically Derived Aortic Valve Area Using a Previously Derived Equation to Account for the Effect of Pressure Recovery (source) Wherein the matter of cath vs. echo discrepancies in evaluating aortic stenosis is addressed. While this article focuses on the matter of the aortic valve area, prior work

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-5429706561513317662008-07-20T09:54:00.001-07:002009-11-11T07:22:03.992-08:00

After overcoming my perplexity about the distribution of left atrial scores, I thought it might be interesting to look a little closer at how other normative data is predicted. For the sake of simplicity and to illustrate the point, the estimation of BSA from height and weight has been omitted and the Cincinnati z-score calculation is limited to "boys". Aortic Valve Z-Score Comparison

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-24284969365724421142008-07-19T16:49:00.000-07:002008-09-12T09:06:29.983-07:00

"...these could easily be included in echocardiography software, which would allow automated generation of an LV mass-for-height z score and percentile for each child undergoing echocardiography." A Novel Method of Expressing Left Ventricular Mass Relative to Body Size in Children [link] Bethany J. Foster, MD, MSCE; Andrew S. Mackie, MD, SM; Mark Mitsnefes, MD; Huma Ali; Silvia Mamber, MD;

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-20132365761225932282008-06-29T22:59:00.000-07:002008-10-20T07:53:57.042-07:00

  Lots of people have asked me something like: We are finding discrepancies in Z scores calculated by your method and the Z scores calculated by software provided by Boston... WHY ? I usually feel obligated to first set the record straight: these are not my z-score calculations. They are calculators based upon published literature, and I cite the source literature on the same page as

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-89498046212180381772008-06-27T07:07:00.000-07:002008-10-27T20:01:44.665-07:00

According to the Spring issue of the ASE's Pediatric and Congenital Heart Disease Council News, interesting things are afoot: The council has developed a Normative Database working group... to develop consensus methods for standardization of measures acquired during the pediatric echocardiogram with a long-term goal of creating a normative database of universally available standardized

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-65839106359505499312008-06-11T23:20:00.000-07:002008-07-17T23:24:13.218-07:00

Reference values for fetal ventricular wall thickness are not easy to come by. This gadget is based on one of few available references. Evaluation of Fetal Heart Dimensions from 12 Weeks to Term Cora Firpo, MD, Julien I.E. Hoffman, MD, and Norman H. Silverman, MD Am J Cardiol 2001 [link] Measurements of the ventricular walls and septum were made from the "4-chamber" views,

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-20908591176281591272008-04-21T12:42:00.000-07:002008-07-20T12:45:53.098-07:00

This article is/will be absolutely huge for many pediatric echo labs: J Am Soc Echocardiogr. 2008 Apr 10 [Epub ahead of print] (PubMed link) Regression Equations for Calculation of Z Scores of Cardiac Structures in a Large Cohort of Healthy Infants, Children, and Adolescents: An Echocardiographic Study. Pettersen MD, Du W, Skeens ME, Humes RA. Carman and Ann Adams Department

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-82394179854370546772008-04-11T07:44:00.000-07:002008-05-20T07:45:40.613-07:00

The question is between two definitions of "95% of normal". On the one hand is the camp, like those describing the Strong Heart Study, that says: Normal is a z-score of ± 2 Their 95% is the same 95% that is the confidence interval, i.e.: 95% of the population falls within 1.96 standard deviations of the mean- the middle 95%. We normally round the 1.96 to 2... and that is one way to

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-52029669559407140662008-04-09T05:42:00.000-07:002008-07-22T05:45:53.682-07:00

In what appears to be some small bit of determinism of my own, I have arrived at this point in the implementation of a data-driven, standardized echo report: Can we use z-scores to determine the severity of abnormal findings? Certainly, we are already doing this- with widely varying effect: And, from my recent ad hoc survey: To me, it seems as though there continues to be no consensus-

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-6293809577334449062008-04-03T05:30:00.000-07:002008-07-22T18:14:09.237-07:00

So, you have your Z-Score. Now what? Certainly, you can use it to dichotomize your findings into normal or abnormal. Possibly, you might use the z-score to further stratify your abnormal findings into mild, moderate, or severe (dilatation or hypoplasia)- which leads me to a couple of central questions, which may challenge some accepted practices: what z-scores do you consider normal?

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-65662716559256133162008-03-02T06:47:00.000-08:002008-08-05T05:42:39.306-07:00

My physiology professor called them "cartoons". One of our docs here called them "valentines".   However you refer to them, the diagrams that comprise Congenital Heart Disease, A Diagrammatic Atlas are, without a doubt, indispensable for students and practitioners of pediatric echocardiography. Sadly, according to most online retailers, this atlas is no longer published. If you can find a

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-65389565626575147892008-02-17T05:47:00.000-08:002008-08-29T08:51:04.616-07:00

(Note: the calculator is now HERE ) I finished off what I thought were the more useful z-score calculations based on data from the article "Normal values of M mode echocardiographic measurements of more than 2000 healthy infants and children in central Europe" (link). Included in this calculator are z-scores and normal ranges for: right ventricle (RVDD) ventricular septum (IVS)

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-37943523045240651832007-12-15T13:43:00.000-08:002008-09-03T14:56:54.292-07:00

Ebstein's anomaly is a malformation of the tricuspid valve and right ventricle. The classic description is something along the lines of: a tethered and displaced septal (and posterior) leaflet, a "sail-like" anterior leaflet, and a variable "atrialized" portion of the right ventricle. Echocardiographically, it is important to understand the measurable parameters that help describe the spectrum of

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-32238304569901393512007-12-08T14:20:00.000-08:002008-10-15T15:21:59.965-07:00

The fetal echo z-score calculator was initially a proof-of-concept project (as were all of the calculators at ParameterZ.com). It has since proven itself to be quite useful, and I refer to it for nearly all fetal echos now. However, a shortcoming of the current calculator is highlighted by this common referral: SGA (Small for Gestational Age) RV > LV LV measures lower limits of

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-30967464605880796022007-12-08T11:31:00.000-08:002009-10-06T13:50:54.687-07:00

Users of the Pediatric Cardiac Valve Z-Score calculator might be interested to know about an erratum to the reference article: The tricuspid valve nomograms have been re-published. In the process of refining the calculator on ParameterZ.com, it was noted that tricuspid valve z-scores calculated by the supplied formula differed considerably from the result when using the nomogram. I contacted

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-60823905789555328782007-08-12T07:53:00.000-07:002008-07-20T12:18:37.059-07:00

Big people have big hearts. Little people have little hearts- and mitral valves, aortas, and pulmonary arteries. As a student sonographer, one of the few things I excelled at was committing things to memory. I was all about flashcards. I had flashcards for everything, but particularly for normal dimensions. Normal left atrium? 19-40mm. Normal IVS? 6-11. LV? 37-56. In the adult echo arena this

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-45947210191993304422007-07-21T07:58:00.000-07:002008-08-05T05:43:18.312-07:00

Coronary Artery Involvement in Children With Kawasaki Disease, just published in this month's Circulation, contains a Z-Score gem: updated prediction equations for coronary arteries. These new prediction equations provide one major advantage over the equations of de Zorzi et al.: they account for the tendency towards non-constant variance, i.e. heteroscedasticity. It is interesting to note that,

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-77090077656041114982007-07-13T08:27:00.000-07:002008-05-20T08:30:51.935-07:00

Based upon: ASE Sonographer Core Curriculum Understanding the cardinal directions that are expected in each of the imaging planes will greatly simplify the sonographer's work when evaluating patients with complex congenital heart disease- particularly those patients with dextrocardia. Dextrocardia: heart is positioned in the right chest, apex pointing rightward (as opposed to Dextroposition:

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0tag:blogger.com,1999:blog-3721599568222334905.post-87026528228628702362007-06-01T14:12:00.000-07:002010-02-09T20:02:45.930-08:00

Who am I? My name is Dan Dyar. Natural Habitat? San Diego, CA. What makes me qualified to make anything other than passing remarks about pediatric echocardiography? I am RDCS certified in AE/PE/FE; over 15 years experience "scanning". A 'Fortuitous Concatenation of Shadows'- What is that about? I first heard this from one of my mentors, who picked it up from Baylor. Since then, innumerous others

DanDanhttp://www.blogger.com/profile/03896328643683228349noreply@blogger.com0