what I truly believe is the take home message of this articleand reaffirms the usefulness of the grading system. Thatis, the SFU grading system appears to be an extremelyconsistent vehicle for an individual urologist to use tofollow HN.

Surgical decisions are never made based on 1 US image inisolation. Trends in HN with time serve to complement otherclinical parameters and radiological imaging (renal scintig-raphy or magnetic resonance urography) in the decision

making process. Based on these results the SFU gradingsystem allows the same pediatric urologist to remain consis-tent in readings, which will facilitate this process.

C. D. Anthony HerndonDivision of Urology

Section Pediatric UrologyUniversity of Alabama at Birmingham

Birmingham, Alabama

DISCUSSION

Dr. Max Maizels. Could you please explain how graders of ultrasound came to know what grade they were going to grade?Was it just reading a piece of paper or was it more Socratic where people would actually help the future grader to grade?

Dr. Melise Keays. They were all provided with the same paper outline with no instruction. The study was based on theoriginal publication in 1993, and so the same images with the same descriptors as your paper were used.

Doctor Maizels. So the information you are providing us would be more akin to an in vitro examination rather than anin vivo examination.

Doctor Keays. Well, the staff graders have years of experience.Doctor Maizels. [Interposing] Probably with reading ultrasounds but not knowledgeable really of what they were reading.

So we have come to understand that it is labor-intensive. You have to want the people to know how to read consistently atyour institution. The way to do that is with a dialogue between them and not so much with reading a piece of paper that saysthis is what grade 2 looks like. The sonographers who are really the people doing the ultrasound need to be clued in and notthe radiologist sitting in their chairs.

Doctor Keays. Right. So we have no control over what images the sonographers took nor did we consult with them. Thestudy was done retrospectively.

Doctor Maizels. But you can in the future.Doctor Keays. Yes, absolutely.Dr. Howard Snyder. The Society for Fetal Urology grading system for dilatation of the renal pelvis was well intentioned

but let me tell you why I think it is not clinically useful. If you have an extrarenal pelvis, wide infundibulum and compoundcalices, all of which are normal, with anatomical variance on ultrasound you can get up to SFU grade 2 without any troubleat all with normal anatomy. So the only aspect of the classification that means anything are grades 3 and 4. Therefore, I thinkthe application of it is a snare and a delusion in thinking that the grading system is going to help you with clinicalmanagement because it does not.

Dr. Mike Leonard. This was an in vivo study and these were real ultrasounds interpreted by real pediatric urologists. Thebottom line is that the inter-rate of reliability is not good. We may call it an SFU 3 and our colleague may call it a 4 but itis a real life study.

SOCIETY FOR FETAL UROLOGY HYDRONEPHROSIS GRADING SYSTEM 1683