John U. Hidalgo, MS (on left, with Craig Harris and Tom Haynie)
Sixth president of the Southwestern Chapter (term ending 1962)


January 25, 2005

This is the first of three interviews. Please check back for additional content.

CHARLES METZGER: This is Charles Metzger, and with me on this conference call are Dennis Patton and John Hidalgo. Dr. Patton and I are interviewing John Hidalgo for his historical perspective in the development of the Chapter and in the development of nuclear medicine. So, John, how did you first become involved with Chapter leadership?

MR. HIDALGO: Well, I'd like to begin this conversation with something else if you don't mind. What we had was a hospital called the Touro Infirmary The medical staff at Touro were doing a lot of work in conjunction with Tulane University and Ochsner. The focus at Tulane was on two internists both interested in thyroid problems.

What made the startup of the operation possible was that we had the capabilities at Tulane to work with the radioactivity. We were able to receive and disburse it as necessary, and I had my two internists Sam Nadler (of Touro) and Paul Murison (with Oschner). With this team, we finally were able to make thyroid measurements in the biophysics program at the university. 

Both of these physicians were working pro-bono, and they were doing their work on charity patients as well as their own patients. To get these patients moved from the infirmary to downtown and to bring them up to Tulane University, was challenging. We were set up to do thyroid uptakes. One of the things that bothered me is that's two separate functions of two different locations. It was a strange thing on a nonclinical campus, there would be three or four ambulances in one of the parking areas, where our people were located. All of this happened under those conditions and it was with considerable cross-cooperation between everyone, and most of them did a good job of getting out of the way, so these things went fairly well. We actually got to the stage of doing thyroid measurements with test tubes. That was the obvious way, but to do the diagnostic things downtown and bring the patient up there, we would give the patient the dose 24 hours before, and they would come out the next day and report to wherever the equipment was.

DR. PATTON: Were you using I-131 in those days? 

MR. HIDALGO: Oh, yes. That's all.

DR. PATTON: What was the year, just roughly? What time frame would that be?

MR. HIDALGO: Well, the time frame is a little crazy. I got into that in '55, '53 somewhere in that timeframe. Initially, we started loading the diagnostic capsules by hand, and then our physics people were able to build the machine that was able to load the capsules. We also had other things going at that time, measuring blood volume. We followed that a good bit, and that had some other outfalls from some of the other things we did.

DR. PATTON: What tracers did you use for blood volume? Was that labeled plasma with the albumen or white or red cells? How did you do that?

MR. HIDALGO: We didn't start with the cells. We started with labeling the product directly into the plasma tag. Now, those are the things that we would do. The other thing we did was P-32. That was used for blood volume in one phase, the cell tagging. We did a bunch of these things like measuring the rate of disappearance from the patient's blood on the iron study. Although there were other studies, blood volumes were a primary focus. 

Our physicians on these studies were still earning a living as internists. What I'm saying is, both of these guys were working on pretty light ground because they didn’t like to lose time, they were both very active physicians with a good-size practice. Eventually, they had good associate doctors, but not at the beginning.

What was the equipment like? Well, first of all, we had a big bottle in a wooden transport box, and it was in a single vial, of about 20 to 30 cc. It was labeled with the statement that they would not guarantee it because this was coming directly from the radioactivity group up in Oak Ridge. So we got these vials in, and, first, we had to develop a system to assay it. These guys would send a box to us, and we had a system where we had to dilute a contact of one cc, and we had to dilute that about 200,000 times. That meant about four or five steps. When we were finished with the dilution, the final sample of I-131 was dropped on a piece of filter paper, that was covered by another piece of paper. This was then placed on top of a plastic planchette. Now, the question was what did you have to count it with? We had a probe, and the probe was what?

DR. PATTON: The Geiger counter or scintillation probe? 

MR. HIDALGO: Neither. We didn't have anything to build one of those things with.

DR. PATTON: A Geiger tube? 

MR. HIDALGO: Yes, sir. And we didn't have a lot of variety. We had one or two. So all of that had to go into the mix, and once the calculations were made based on that final dilution, if it stayed within five percent -- that was our standard -- we would use it. If we didn't use it, we'd send it back. We were getting all this stuff free under the auspices for the Atoms for Peace program. They were supplying all the funds for this.

DR. PATTON: That was brand new then.

MR. HIDALGO: Yes, but, from the patient side of this, we didn't really get scintillation counters until the '50s. The first thing to make these things work was to build a stable high-voltage supply. Without that, that's just a wandering goose going around. Craig Harris designed the power supply and designed the singular counter.. With discriminators and without that little tumble, we might still just be talking about spinning something else. Those were all critical. 

I met Craig Harris in Oak Ridge, in '54 or '55, maybe '56. I met him, Marshall Brucer, Ross and his staff at the Oak Ridge Facility. There were about six or seven people with different designations. We had a radiochemist to build structures for sources to be evaluated. We also made all of the mannequins. 

The first time I met Brucer, I took my wife and my technologist, thinking that they would get something out of it. By that time, we already knew that it was the nuclear center of the world. Brucer said, “Come on out any time.” So I said, “Okay, well, we're coming out.” I told him about bringing my wife and so on. “Come on. Bring them all.” Anyhow, when we arrived, he took us on a little tour around. He took us into his office, invited us to sit down, and the first thing he said was, “You know, I've been working on a new system to try and improve the delivery of doses.” He said he really thought that the core was to pursue the electrons. That was where all the information was.

DR. PATTON: Pursue electrons? 

MR. HIDALGO: Yeah, the beta particles. Oh, this gets way out from here on because I did something I had never done before. I wasn't old enough for this yet. I reared back in my chair, and I said, “Well, I find that a little strange, Dr. Brucer!” That's where we were, and I told him that the energy deposition didn't match all of this. I started running off the numbers, and the two ladies there with me were getting a little nervous. They both thought I was misbehaving, but, anyhow, we got into this a little further along, and I said, “No, I don't think so.” and he still disagreed Anyhow, we left there with my head hanging down because I had met the grand vizier on this subject, and nothing works. I went back to the lab and got started getting my work done when a week later I got an envelope coming from Oak Ridge. It was a contract as a consultant. I was able to go up there about every two or three months and mingle with these guys. He would bring out phantoms that he had. I never knew how many people were in that particular committee, but it probably was somewhere between 30 to 50 people. Most of those that were there were part of that particular group. We met people from all over the country. There were people from the Oregon nuclear laboratory; there was one individual from New York. There were a couple of folks from the west coast, including one from the University of Berkeley. Anyhow, this is what we did, and we were the kind of group that he wanted because you didn't go in and say, “Yes, sir” first. You'd say “What do you want to fight about today?” and that's about the way we did it. It was convivial and so on, but, you know, Dr. Brucer had to take his lumps coming back. The next thing after that, was he built these several mannequins. They were set up to be a test patient, and as it turned out, it was an excellent study. They didn't develop any strange counting losses because of this. Mock iodine was the final product. This is way past that, and Harris is in all of this as well, but they were building this thing so they could simulate the source and they called it mock iodine. It was balanced off, As it was a mixture of barium-133 and cesium-137 which is really barium-137m when it decays.

We got the results on some of this because he decided he wanted to make a standard for thyroids, using I-131 with all of the standards and the secondary’s. Got all of that fitted, in place, well the whole thing was the mock iodine, but he wanted to be able to show that he could design a system and take the measurement using another hospital. The questions were large because, first of all, with the original iodine measurements, you could not use it very long. It has a short half-life, and you can't compare a patient with anything if that person didn't reside or abide within, say, three or four days to get anything controllable, so that's what brought him into the transport issue. He had to have something that could be transported safely and be able to use it at a distance, and he found out a way to do it because it wound up at the Sorbonne and also King's Hospital in London. These things went everywhere and they all sent their results back, but they were sent to them blind. There were three different models of this, and you couldn't tell them apart unless you knew what the numbers were. They were marked high, medium, and low and that was going to be the activity that was in the thyroid pellet itself and one would represent the high uptake patient, the other one at the lower end would be perhaps a little on the low side below normal, and then the medium thyroid group is in the middle. He sent one at a time to these places, and they were going to send back their results. 

He also had individual dose configurations. Some of them were about 8 to 10 cc and we made it a test tube. We made it as a small and long test tube. He also designed the first phantom that was used for this purpose, and there was also a simulated thigh made with those things. Everything was fine, and he starts getting the results in. Eventually, he had done something like 500 or 600 of these things in this country, and a smaller number in England. Of course, they didn't believe us anyway. So it really didn't matter too much, but, we got the mannequins back, and he compared them with what the results were, and they were very discouraging. The high tubes ranged all the way from on the uptake image of this or the data from that came up with something about five percent. His patient was five percent , and yet he had gotten 60 percent in the dose, and on the other end those continued at the others. There was a group of them. There was no gentle growth, no gentle curves to go through this and it was bad, and it convinced him and the AEC to throw a little money his way. That was with the ORINS operation. ORINS was the name of the laboratory—Oak Ridge Institute of Nuclear Studies. And that's where the Y-12 and X-10 were. Y-12 was where the universities in all of these centers were associated, and that's where the funding came from also. 

We've got them out there. Dr. Bruce designed everything, and it all wound up in that book. He built all the systems, and then sent the stuff back out, and everybody could see what their instruments were doing. It worked out very well because they used the Brucer system. I call it his because he deserved it. That one worked, and you could do a thyroid uptake and you could justify it and defend it. They matched the gamma rays in the scattering for the thigh and also over the neck. Those that built the system faced many challenges in designing the phantom, and it was fascinating because the phantom was a major challenge. You had to make all of these things so they would synthesize the gamma radiation that would result from the scatter or from direct radiation effect. We fought over the timing of the patterns a lot. That was the business of how to do it, and there only appeared to be one way that you could defend it were it wouldn't disturb the entire project. One of the aggravating lines out of all of this was that the timing was set up for 24 hours. Now, it went through the biology and by this time we had scintillation counters, single tubes, small . Some of our first ones were one inch in diameter and were about an inch long. Not a very impressive little toy but it worked, and it eventually got better. Then the phantoms all had to be idealized so that the amounts of material in the test modules were going to be the same in each one. Dr. Brucer thundered to get that done and it turned out very well, and everyone was smiling when it was over. From there it gets historical in shorter runs because during all of this time the business of the thyroid uptake was accepted and done. 

First there were patient complaints. They didn't like the idea of coming back for the second day, and that was taken very seriously. So they started doing it at different times. These are the same days where they would do it in two, four, six, or up to ten hours. Well, that left a lot of damage open, and that really said something when you were measuring radioactivity, when you were not sure what you were measuring. No one seemed to have any control over that. That's the way it went, and everyone went through all of this together, and more importantly there were hundreds and hundreds of papers published and no two of them were really the same, and none of them had really any defendable phantom data. You just didn't have a phantom to do it or you used the other phantom, but would it mean anything? How would you know?

When it came to the I-123 becoming the standard we did not have a phantom to match it. I tried! I went to the manufacturer of the I-123 out on the west coast and I said, “Give me $10,000.00 and I will create a phantom and give you the whole design.” The manufacturer rejected the idea, and this was the typical pattern of rejection that we encountered in that era.

In the meantime on some of these other issues, sidebar stuff, , we did get a computer, an old model 650. Because that was in about 1960, and since I was the only one on the campus I was able to run some stuff on it. Everything that I tried ran on the 650 and it would take anywhere from four hours to 2 two days. With all of the technology today everything runs on your laptop and there are no issues with storage That was the difference that we had to work with. 

Now, one of the things that became important were some questions that were raised by our group and our friends on the surgical side. They wanted to be able to easily measure a blood volume, and this is where the blood volume originated from. There was probably more emphasis from the Oschner side than from the others, but they all used it. We had a wonderful time there because if we wanted 300 patients, we could get 300 patients. It was great. I can't picture that sort of thing happening here anymore. We did the blood volume things, and we did it with iodinated albumen -- labeled albumen, we did it with red cells.

DR. PATTON: How were the red cells labeled? P-32 red blood cells?

DR. HIDALGO: That is correct. It was the hardest measurement to make. It was a terrible thing, really. We finally proved that when we did the albumen thing correctly, we didn't need to do the other one, but we did the blood volumes. We took everything we could out of the literature, and we got this, and we asked people for data who had gathered approximately a hundred patients for a trial , and they had all this dataThat they sent us. We wound up with almost 2,000 blood volumes. And that was with every kind of way. We even had some of those that were still being measured by the blue dye. Well, that was the thing that we were dealing with. Now, we did have some extra patients. We picked up about a hundred at the penitentiary. They were real good, they were all sizes, and that was helpful to us. We had one female patient who was about five feet high, five feet wide, and five feet deep, and then we had another guy in there who was about 6'3", and he didn't have any meat on him at all. Anyhow, we came up with a formulation using the transcript. We did the data matching on this, and put the parameter numbers on it, and we could calculate it on the equivalent of what people were doing for body surface area. That sort of thing where all of that stuff falls in place when you get the right numbers in it and that worked. In fact, that's still being published. It's in -- you know the little circular books that were backed by almost every pharmaceutical ad at one time or another. That is our work, Hidalgo and the rest of us help create the tables that were documented in those books. It worked out beautifully, and it worked out beautifully enough so the surgeon felt comfortable. We would measure the blood volume on the patient, and then the surgeons would go ahead and perform whatever they were going to do. Then when that was done and surface relatively cooled off, then we'd go ahead in and measure it again. This was a fairly hotshot surgeon, but he impressed me although that was not usually difficult. 

We got these things done, and it was getting to the stage where we were estimating what the blood loss was. That was tricky, but what they would do is have the patient come out from surgery after having received one or two bottles of IV fluid. You'd give them what they had and then measure them again after that and come fairly close to what the relative difference was. 

That worked pretty well, but that died for another reason too. Nobody wanted to tell the surgeon to wait until we could make this blood sample, and usually the patient was just coming in in the morning anyway, so even our more surgical places like Oschner couldn't get it done, couldn't get it done until the big O got it at one time, and then, boy, everybody was doing it. You know, they'd go crazy. 

DR. PATTON: John, you've been involved in many developments like this, and do you want to pick one and say that that's your proudest moment? Which one would you say this is what I'm most proud of? Like Beethoven and his ninth symphony. What's your ninth symphony? 

DR. HIDALGO: Let's see. I founded the MIRD Committee (Committee on Medical Internal Radiation Dose). I was asked at the time when I was the National SNM president, to form the MIRD Committee. I knew everybody was willing to do that, and they figured how to do it, but somebody had to start it, and I was the one to kick it along. What we got were some surprises especially when I was the first one to be nominated as chairman of this committee. I asked “Who is going to be the chairman?” I guess they assumed I wanted to do it, and then I said, “Now, come on, fellas. You know, look. Let's get out of that.” Because there's no way you're going to get a committee that's going to work of any large size. You've got to have something small. You've got to have maybe three people, five people, and figure you're only going to get two of them to do any work anyway. And that's the way it will go. That's what they wanted. Come to find out that there was a whole bunch of people around the country who wanted to participate in it, and we had people coming down from Oregon and Chicago and other places throughout the United States. The end result out of all of this was, it was done with the world’s largest computer. Including the computer that was at Oak Ridge there were two other computers that belonged to the military. One of them was in New Orleans area, and one of them was somewhere else.

I'm sitting back and watching the process of creating these mannequins. They designed a man, a woman, and a teenager to get relative sizes, locations, and relative shapes of parts of the body. You see pictures of all of these things now, what they did back then when they built this thing was they designed a computer program which it would take any given point and begin with that and plot out all of the interactions that would happen from that until it got out of the zone it was on. 

Now, that sounds simple, but that computer was something else. They finally came up with a program called the Monte Carlo program. That comes right out of the statistics program and with the Monte Carlo method. It does all the measurements for you, and it gives you the essential result of everything that you've done put together, and there it was.

CHARLES METZGER: What's being measured here, relative exposures?

DR. PATTON: The exposure to any organ from any other organ or from itself. 

MR. HIDALGO: Yes, yes. All you're doing is expanding the system. In other words, what you're doing if you did two of them, you do both of them even if they're not next to each other. They defined the limits on that, and it says do everything in both of those places. 

CHARLES METZGER: How did you first become involved in Chapter leadership or involved in the Chapter, period. I guess it was founded a couple years after you got involved there at Touro?. How did you get involved with the Southwestern Chapter and then eventually with leadership? I really am interested in your perspective on the Southwestern Chapter because not only were you a trustee, and a president, but also the executive director for quite a while. So your reflections on the Chapter would be great.

MR. HIDALGO: Well, I first got involved in the radioactivity thing. When that happened, really when our university had the access to do this, and we checked it out with the ORINS (Oak Ridge Institute for Nuclear Studies), and we got involved with some stuff there. I went to college, and my intent was to do a nuclear focus program. Now, that doesn't bear a lot of relationship to anything, except that it just happened to be there, and also there were these two physicians, these two internists and Marshall Brucer. All of these things kind of came almost by divine intervention to get all of the right pieces in the right place. And mainly we joke about Brucer, but he was a very serious guy, though he loved to play jokes on you. He kept you on the edge of your chair.

We were unusual people to a large extent. And some of it was good and some of it was bad, but it was all fun, and it all went that way. There were no big fights about anything really, and we were all kind of focused on the same spot, just from different corners. I knew most of the people that were there. We had meetings, the first meetings of the Society. 

CHARLES METZGER: Like Henry Turner and Jack Maxfield, Herb Allen?

MR. HIDALGO: Herb Allen. That was the name I wanted to think of. He was the first one to stand up at a meeting and say, “I am now designating my practice. I am going to practice nuclear medicine full time, period.” Everybody else involved were part-timers. And some of those were surgeons that had their interest piqued in what they wanted to do. Maybe it was a kind of a filtering in some senses, maybe it was bringing all the bad guys in one place or it was the other way around, but we were all on a common level. 

One of the other things that was very important, that I didn't tell you about, was how do I talk to a physician when I first meet him? Do I talk to him like a patient? We finally made a little pact, putting everything together so that we could communicate to each other, on different levels. I could talk to Paul Murison, if I was going to talk English, or we could talk physics. That’s where it was. It was just about that far. What we did a number of times was we'd be traveling together, and if we were from different disciplines, we would teach each other stuff. I can remember Sam Nadler trying to make me a first class card player, but it stimulated what we needed to communicate throughout the process. It became routine, were I could talk to these people, and they could speak to me one level terms. I ran a training school in New Orleans in the 1950’s, and I started a program for anybody who wanted to attend. 

It was fun to see some of these things going. Here I was. This little young punk, and there's this guy in the back who's got gray hair, and he says, “What the hell do you mean? What are you talking about?” You know, trying to show them something about how decay worked. That took a little explanation, but those were interesting times. We ran that class once a week and it ran for 13 weeks, and then there was a Spring segment as well where we tried to integrate it a little bit more with some of the available tests that we were using. I think that was kind of an important thing. It could have happened anywhere. In the other parts of the world, they had to do that too, didn't they? 

DR. PATTON: Sure. It was going on in Europe too. 

MR. HIDALGO: All right. You're sick. You go to a physician and he's going to have to explain it to you. That's one part of it. The other part of it is that if you have to do very much of this, then the receiver and the transmitter need to have some match. 

I find now, most of my physics friends and others, now I can go to a meeting of SNM or anybody else, and I can follow what's going on pretty reasonably well. I can understand what they're saying. I can translate what I want to hear from the rest of it. What I'm saying is that this was a had-to-be type of thing.

DR. PATTON: Between clinicians and scientists?


CHARLES METZGER: When I go back to those early meetings of the Southwestern Chapter, I think some of those first meetings must have had a dozen, two dozen, three dozen people. Right? We don't have attendance records. 

MR. HIDALGO: Sometimes as few as three dozen, but usually we had more than that. We met often enough because we felt the urge to convene. We had quite a few meetings in Texas where we would meet people from many different places and spoke multiple languages. In between the training, you would get a group of professionals who could speak more than one language comfortably, then you tend to become much more flexible, and that is how it works. Now, as far as the politics of it, well, the politics are the politics. 

DR. PATTON: Well, John, I've promoted you as quite a pioneer, and I feel that you are definitely living up to that billing. 

MR. HIDALGO: Well, thank you, but the point of all of this was the people. They were almost like the guys going west. I can do this, but am I ready for it? And of course the world of physics was and to some extent still is an alien language. It wasn't just speaking English to each other. We had some fun times with some of these small groups. For example, one time we went to go in there, and we were supposed to do a twosie, you know, with two people. One of them was going to be Craig Harris and the other one was going to be me, and we were taking the opposite position on the virtues of various things that we were dealing with. We worked it out pretty hard because we didn't start with too many preconceptions. It was a fun thing. It was about an hour and a half. We had a session on that, but the meeting of the people and the quality of the people that we met wherever it was, these were always the kind of people that were looking for something better.

Frankly, I was thoroughly amazed how often we found people who were interested to the extent that they would give up part of their practice as a full-time physicist. Well, we never worried about money. We didn’t get any, but that's all right. The thing is: this was one of the times that I had seen firsthand what happens to someone who really gets motivated, and most of the people that we started with even if they didn't find their way into the way to get into there, then they'd go away. Once we got to where we had a name for it and started training students, particularly fellowships and things like that. It worked but the classes that I gave, for example in New Orleans, were held at Tulane or wherever we could get a room to meet. That was fine, and we had people coming in from Touro, from Baptist, the other hospitals and the teaching hospitals, and they'd come and they'd turn out. It wasn't a question of going to class. It was a question of, “What time? Let's get there!” We had a lot of good people, lot of good people.