WEBVTT 00:00.000 --> 00:30.000 position:50% align:top line:0% *This machine-generated transcript may have errors. If remediation or a manually-generated transcript is needed, please contact NLM Support at https://support.nlm.nih.gov.* 00:06.070 --> 00:08.819 Health Care Today is a series of programs in continuing medical 00:08.829 --> 00:11.510 education and is presented by the Faculty of Health 00:11.520 --> 00:13.350 Sciences mcmaster University, 00:13.500 --> 00:15.670 the Ontario Medical Association 00:15.729 --> 00:17.059 Mohawk College, 00:17.069 --> 00:19.690 the Ontario Chapter of the Canadian College of Family 00:19.700 --> 00:20.590 Physicians, 00:20.600 --> 00:23.069 the Hamilton Academy of Medicine and 00:23.079 --> 00:24.729 CHCH TV. 00:25.059 --> 00:26.389 Here is Doctor Michael Moot, 00:26.629 --> 00:29.610 assistant professor of radiology at the Faculty of 00:29.620 --> 00:31.969 Health Sciences mcmaster University. 00:32.490 --> 00:34.930 Our subject for tonight's program is 00:34.939 --> 00:37.259 computerized tomography of the head. 00:37.880 --> 00:40.659 This method was first introduced approximately two 00:40.669 --> 00:43.569 years ago and it has since revolutionized the 00:43.580 --> 00:46.090 investigation of 00:46.099 --> 00:48.549 diseases of the brain and its surrounding 00:48.560 --> 00:49.290 structures. 00:50.810 --> 00:53.279 It combines an X ray tube with a 00:53.290 --> 00:56.240 computer and allows the radiologist 00:56.250 --> 00:59.150 or physician to assess the inter cranial 00:59.159 --> 01:01.520 structures which conventional 01:01.529 --> 01:04.050 radiologic invasive and non 01:04.059 --> 01:05.379 invasive methods have. 01:05.389 --> 01:08.059 Heretofore been unable to provide 01:09.400 --> 01:11.019 at the Hamilton General Hospital. 01:11.029 --> 01:13.650 We have in the past two years carried out 01:13.660 --> 01:16.559 almost 3500 such examinations 01:16.569 --> 01:18.940 and have founded an invaluable method in the 01:18.949 --> 01:21.900 investigation of patients who present with 01:21.910 --> 01:24.480 problems related to the brain and its 01:24.489 --> 01:26.095 surrounding structures. 01:26.385 --> 01:29.084 Perhaps to better illustrate the 01:29.095 --> 01:31.495 capabilities of the scanner and the method 01:31.504 --> 01:34.055 involved Dr Joseph Homer, 01:34.065 --> 01:36.654 a family practitioner from Hamilton will 01:36.665 --> 01:39.415 present us with the case of a patient that came to 01:39.425 --> 01:41.525 him in September of last year. 01:41.934 --> 01:42.334 Thank you. 01:43.114 --> 01:46.044 This was a 49 year old male who presented 01:46.055 --> 01:48.385 with a history of weight loss in hems. 01:48.394 --> 01:51.275 A routine chest X ray was ordered during investigation, 01:53.279 --> 01:55.900 we can see on the chest X ray that the 01:55.910 --> 01:58.150 patient had a large mass in the left. 01:58.300 --> 02:00.050 Harlem and Joe, 02:00.059 --> 02:02.949 the answer was this turned out to 02:02.959 --> 02:04.889 be a proven carcinoma of the lung. 02:05.000 --> 02:05.519 However, 02:05.529 --> 02:08.460 the patient was also confused and complaining of left sided 02:08.470 --> 02:08.990 headache. 02:09.330 --> 02:11.949 A consultation was sought from a neurosurgeon 02:12.360 --> 02:15.210 and a cerebral angiogram was performed. 02:16.460 --> 02:18.910 We did carry out the angiogram and 02:18.919 --> 02:20.089 surprisingly, 02:20.100 --> 02:22.830 it showed a solitary lesion in the 02:22.839 --> 02:24.830 left high frontal region. 02:25.820 --> 02:26.820 Question arose, 02:26.830 --> 02:28.949 Mike whether this was a single lesion, 02:28.960 --> 02:31.800 a solitary metastasis or whether it was a 02:31.809 --> 02:34.759 coincidental primary cerebral tumor or 02:34.770 --> 02:35.589 whether in fact, 02:35.600 --> 02:38.410 there may be multiple lesions in the cerebra in 02:38.419 --> 02:40.380 which the angiogram failed to demonstrate, 02:40.839 --> 02:43.410 the CT scan was therefore requested. 02:43.589 --> 02:45.750 But perhaps before discussing those results, 02:45.759 --> 02:48.570 you might give us a brief explanation of 02:48.919 --> 02:51.740 how the CT information is obtained. 02:54.070 --> 02:57.000 If we look at the 02:57.009 --> 02:59.880 diagrammatic representation, 03:00.190 --> 03:02.630 we see an X ray tube and the X 03:02.639 --> 03:05.339 rays enter the head and 03:05.350 --> 03:08.279 those leaving the head are picked up by two detectors. 03:08.289 --> 03:10.509 These are sodium iodide detectors 03:10.740 --> 03:12.860 which emit light 03:12.869 --> 03:15.720 rays and these light rays are then 03:15.729 --> 03:17.880 converted into an 03:17.889 --> 03:19.679 analog or voltage. 03:19.690 --> 03:22.089 And in turn into a digital 03:22.100 --> 03:24.389 value or binary number. 03:24.529 --> 03:27.479 These numbers are then stored temporarily in 03:27.490 --> 03:29.059 a magnetic disk unit. 03:29.320 --> 03:32.169 And the computer calculates these digits 03:32.179 --> 03:35.100 for final values which are then returned to the 03:35.110 --> 03:37.820 magnetic disk unit for permanent 03:37.830 --> 03:38.580 storage. 03:38.830 --> 03:41.210 These numbers are then 03:41.220 --> 03:43.610 reconverted back to a voltage system. 03:43.679 --> 03:46.600 And the voltage system then allows us to 03:46.660 --> 03:49.259 view the image of the brain 03:49.350 --> 03:52.240 with a cathode ray display 03:52.250 --> 03:52.710 tube. 03:52.770 --> 03:55.649 We then take a polaroid picture of 03:55.660 --> 03:58.550 the display for our own permanent records. 04:00.889 --> 04:03.860 This is a representation of the head encased in 04:03.869 --> 04:05.970 a rubber bag and further 04:06.429 --> 04:08.830 encased in a water sealed 04:08.839 --> 04:09.919 box. 04:09.970 --> 04:12.929 This is called the scanning gantry and it 04:12.940 --> 04:15.190 consists of the X ray tube and the 04:15.199 --> 04:16.220 detectors. 04:16.239 --> 04:19.000 The gantry passes the head in 04:19.010 --> 04:20.290 one movement. 04:20.609 --> 04:21.779 As we see here, 04:21.790 --> 04:23.299 it rotates one degree, 04:23.809 --> 04:26.489 makes another pass a further degree and another 04:26.500 --> 04:29.279 pass and we get a total of 180 degrees 04:29.290 --> 04:30.899 over 4.5 minutes. 04:33.089 --> 04:36.040 The levels of scan that we 04:36.049 --> 04:38.970 do use are basal scans 04:38.980 --> 04:41.540 at 25 degrees to the orbital 04:41.769 --> 04:44.239 metal line and we carry out four 04:44.250 --> 04:47.200 scans at 4.5 minutes each or 18 minutes in 04:47.209 --> 04:47.809 total. 04:48.130 --> 04:51.100 The first scan is basal and then just 04:51.109 --> 04:51.750 moving up. 04:51.760 --> 04:54.739 So we cover approximately 12 centimeters which 04:54.750 --> 04:57.420 in the vast majority of patients will include their 04:57.429 --> 04:59.929 entire brain and the intercranial structures. 05:00.899 --> 05:03.899 Perhaps we might see the scanner in action by 05:03.910 --> 05:05.440 reviewing a film clip. 05:07.160 --> 05:09.750 Here is Mr Walton, 05:09.760 --> 05:12.519 our technician who has just 05:12.529 --> 05:15.420 turned on the computer and is now 05:15.429 --> 05:18.399 giving information to the computer with regard 05:18.410 --> 05:19.119 to the patient. 05:20.040 --> 05:22.799 She is now marking the patient's head in order to 05:22.809 --> 05:25.670 have the basal skin at the appropriate 05:25.679 --> 05:28.130 level and she'll know, 05:28.890 --> 05:30.200 get the patient set. 05:32.149 --> 05:35.040 And it's extremely important that the patient 05:35.049 --> 05:37.859 be immobilized in as comfortable a 05:37.869 --> 05:40.470 position as possible because any movement at 05:40.480 --> 05:43.369 all will interfere with our skin 05:43.380 --> 05:45.339 and cause many artifacts. 05:45.350 --> 05:48.160 So the patient is immobilized and 05:48.170 --> 05:51.000 held relatively firmly by means of 05:53.200 --> 05:55.390 the immobilizing 05:56.790 --> 05:57.679 bans. 05:59.510 --> 06:02.149 It's very important that we calm the patient 06:02.160 --> 06:05.029 down and make them realize that this is not a painful 06:05.040 --> 06:05.799 procedure. 06:05.839 --> 06:07.880 It is not invasive in any way. 06:08.130 --> 06:10.920 These crossing bands are 06:10.929 --> 06:13.850 merely to hold the head in position and 06:13.970 --> 06:14.750 it's just, 06:14.760 --> 06:17.470 they're just velcro bands if you 06:17.480 --> 06:20.179 can visualize the water. 06:20.380 --> 06:22.869 Now encasing or increasing, 06:22.880 --> 06:25.579 I should say around the rubber bag and this holds the 06:25.589 --> 06:26.640 patient in place. 06:27.339 --> 06:30.250 The X ray X 06:30.260 --> 06:31.500 rays are then turned on. 06:32.739 --> 06:35.549 And here we are viewing the patient from the control 06:35.559 --> 06:38.480 room and now we're within the control room itself or within the 06:38.489 --> 06:39.570 scanning room itself. 06:42.140 --> 06:44.739 This is what the Cathode ray display looks 06:44.750 --> 06:45.230 like. 06:45.239 --> 06:46.730 And the Polaroid camera, 06:47.079 --> 06:49.880 which Mrs Walton is now 06:49.890 --> 06:50.500 using, 06:50.519 --> 06:51.809 she'll take a film, 06:52.320 --> 06:55.220 assess it and depending on what we see 06:55.230 --> 06:57.799 on this scan as well as the other basal 06:57.809 --> 06:58.510 scans, 06:58.519 --> 07:01.029 we may or may not go further. 07:01.040 --> 07:02.350 If we're at all concerned, 07:02.440 --> 07:05.260 we inject a contrast medium which is 07:05.290 --> 07:08.250 very similar to an intravenous plog gram or an 07:08.260 --> 07:11.160 angiogram and we then repeat the 07:11.170 --> 07:12.619 appropriate scans. 07:12.630 --> 07:14.890 And this is a scan following 07:15.040 --> 07:17.559 the injection of 07:17.570 --> 07:18.329 contrast. 07:20.250 --> 07:23.059 Perhaps it might be a good idea to 07:23.429 --> 07:26.420 illustrate what the normal scan looks like. 07:26.429 --> 07:29.429 And the first 07:29.440 --> 07:32.000 one we have is a basal scan showing the 07:32.320 --> 07:33.440 Petri bones, 07:34.059 --> 07:37.000 the cerebellum and the temporal 07:37.010 --> 07:39.589 horns as well as the frontal horns more anteriorly. 07:39.600 --> 07:42.470 And you can see the slice of the brain at 07:42.480 --> 07:44.970 the same level with 07:44.980 --> 07:47.869 the same anatomical features. 07:48.829 --> 07:50.579 A slightly higher 07:50.660 --> 07:53.059 slice illustrates well, 07:53.070 --> 07:54.529 the ventricular system, 07:54.540 --> 07:55.690 the pineal gland, 07:55.700 --> 07:57.220 the right ch choroid plexus. 07:57.260 --> 08:00.200 And here is the right choroid plexus and 08:00.209 --> 08:01.880 the ventricular structures. 08:01.890 --> 08:04.779 It's quite obvious that the cerebral spinal fluid 08:04.855 --> 08:07.065 pathways are very well illustrated 08:07.165 --> 08:09.635 with this investigation and don't 08:09.644 --> 08:11.984 require injection of 08:11.994 --> 08:14.385 air or contrast media 08:14.445 --> 08:15.005 again, 08:15.015 --> 08:17.755 just a little bit higher showing the ventricular 08:17.765 --> 08:18.424 system. 08:18.434 --> 08:20.785 And the interhemispheric fissure. 08:21.790 --> 08:24.239 A very high scan illustrates the 08:24.250 --> 08:26.769 many superficial cerebral palsy over the 08:26.779 --> 08:28.279 convexity of the skull. 08:28.290 --> 08:31.000 And this of course is very important in assessing a patient 08:31.010 --> 08:31.410 with 08:33.148 --> 08:36.098 significant dementia or atrophy of 08:36.109 --> 08:36.739 the brain. 08:38.229 --> 08:41.208 This slide is to illustrate 08:41.218 --> 08:43.638 how well we can see the eyes. 08:43.758 --> 08:44.479 In fact, 08:44.489 --> 08:45.638 if you look very closely, 08:45.648 --> 08:47.559 you can see the lens of each eye. 08:47.648 --> 08:49.669 This is these are the paris bones, 08:49.679 --> 08:50.879 the fourth ventricle, 08:50.888 --> 08:52.239 the sphenoid sinus. 08:52.499 --> 08:54.809 And just by playing with our 08:54.818 --> 08:55.679 measure, 08:55.689 --> 08:58.388 we are now able to better visualize the optic 08:58.398 --> 08:58.758 nerves. 08:58.768 --> 09:01.669 This is exactly the same scan as the one 09:01.679 --> 09:02.559 we've just seen, 09:02.638 --> 09:05.018 but we've highlighted the 09:05.028 --> 09:07.820 orbits like what were the 09:07.830 --> 09:09.450 results of the scan on my patient? 09:10.070 --> 09:10.409 Well, 09:10.419 --> 09:10.630 Joe, 09:10.640 --> 09:13.409 it's very interesting if 09:13.419 --> 09:15.770 we look at the 09:16.349 --> 09:18.250 injection or sorry, 09:18.260 --> 09:19.969 the scan prior to injection, 09:20.109 --> 09:22.909 there is a suspicious area of high 09:22.919 --> 09:25.010 density in the 09:25.219 --> 09:28.179 left posterior parietal region. 09:28.190 --> 09:29.679 And when we gave contrast, 09:29.690 --> 09:31.979 it became evident that it was an obvious tumor. 09:32.320 --> 09:32.909 However, 09:32.919 --> 09:35.299 there's also other areas of concern 09:36.309 --> 09:38.719 which would suggest to us that we're dealing with multiple 09:38.729 --> 09:41.349 metastases as we go up 09:41.359 --> 09:41.919 higher. 09:41.929 --> 09:42.450 Again, 09:42.460 --> 09:45.330 you can see just sort of a 09:45.340 --> 09:48.280 modeling look or modeled appearance which 09:48.289 --> 09:49.469 isn't normal. 09:49.479 --> 09:51.200 But once we gave the contrast, 09:51.210 --> 09:52.750 it became evident that there were many, 09:52.760 --> 09:55.719 many metastases in the brain and 09:55.859 --> 09:56.640 unfortunately, 09:56.650 --> 09:59.200 a very poor prognosis mike, 09:59.210 --> 10:02.090 can you expand a little bit on the advantages and value of 10:02.099 --> 10:04.770 scanning in more specific disease 10:04.780 --> 10:05.229 entities? 10:05.239 --> 10:05.840 For instance, 10:05.989 --> 10:08.919 it must be of tremendous value in assessing abnormalities of 10:08.929 --> 10:10.320 the CSF pathways. 10:10.460 --> 10:11.799 It certainly is Joe 10:13.090 --> 10:15.619 just a few illustrations here is an example of a 10:15.630 --> 10:18.330 patient with a very significant atrophy of the 10:18.340 --> 10:18.909 brain. 10:19.090 --> 10:22.049 The ventricles are quite enlarged and as 10:22.059 --> 10:23.229 you saw in the normal, 10:23.239 --> 10:26.080 they were in no way close to this 10:26.090 --> 10:26.419 size, 10:26.429 --> 10:29.059 the frontal horns are grossly enlarged and on a 10:29.070 --> 10:29.979 higher cut, 10:31.150 --> 10:33.950 we can see how the occipital poles 10:33.960 --> 10:36.020 themselves are large as well. 10:36.119 --> 10:38.960 The superficial cerebral palsy are widened. 10:39.130 --> 10:42.119 And what we can 10:42.130 --> 10:43.909 say from this is that this is a non 10:43.919 --> 10:46.530 obstructive atrophy of the 10:46.539 --> 10:47.039 brain. 10:48.299 --> 10:49.590 As opposed to that. 10:49.599 --> 10:51.280 Here is a case where again, 10:51.289 --> 10:53.530 we have relative enlargement of the ventricles, 10:53.539 --> 10:55.450 but we don't see any superficial sulfide. 10:56.070 --> 10:58.950 And this is most likely a case 10:58.960 --> 11:01.780 of normal pressure hydrocephalus where we have a 11:01.789 --> 11:04.719 block to absorption of cerebral spinal fluid at the 11:04.729 --> 11:07.059 level of the tentorium or the superior sain 11:07.400 --> 11:08.030 sinus. 11:10.119 --> 11:12.570 And here's one more example of 11:12.700 --> 11:15.210 the spinal fluid pathways. 11:15.219 --> 11:15.940 But in this case, 11:15.950 --> 11:17.890 we have an obstructive hydrocephalus, 11:18.030 --> 11:20.630 presumably at the level of the aqueduct of 11:20.640 --> 11:23.489 Silvius with gross enlargement of the third 11:23.500 --> 11:25.200 and the lateral ventricles. 11:25.210 --> 11:27.349 And this patient would have required shunting. 11:28.869 --> 11:31.599 Mike is the scanner uh valuable in cases of head 11:31.609 --> 11:31.979 trauma. 11:33.469 --> 11:33.940 Yes, 11:33.950 --> 11:36.609 it certainly is Joe and perhaps I 11:36.619 --> 11:39.150 can show you a few illustrations of 11:39.159 --> 11:39.630 this. 11:39.640 --> 11:42.419 The major problem we have in dealing 11:42.429 --> 11:45.000 with patients who have had trauma is 11:45.010 --> 11:46.030 immobilizing them. 11:46.039 --> 11:47.570 And in certain instances, 11:47.580 --> 11:50.390 it may be necessary to sedate them 11:50.400 --> 11:52.869 and very rarely 11:53.669 --> 11:55.400 give them a general anesthetic. 11:56.940 --> 11:59.359 This is an example of a of a, 12:00.299 --> 12:03.210 a woman in her mid 50 s who 12:03.219 --> 12:05.419 was on anticoagulants for deep vein 12:05.429 --> 12:08.280 thrombosis and unfortunately fell out of 12:08.289 --> 12:10.969 bed while in hospital and hit her 12:10.979 --> 12:12.590 head on the wall. 12:12.659 --> 12:15.020 She lost consciousness and was brought to our 12:15.030 --> 12:17.989 hospital where a scan was carried out immediately. 12:18.080 --> 12:20.479 And here is a typical 12:20.489 --> 12:23.479 large subdural hematoma in the right 12:23.489 --> 12:26.179 posterior parietal region at a level, 12:26.190 --> 12:27.280 a little bit higher. 12:28.440 --> 12:31.200 We can see that not only is there an extra cerebral 12:31.210 --> 12:33.820 lesion but also an intracerebral hemorrhage as 12:33.830 --> 12:34.289 well, 12:34.299 --> 12:36.770 which required aspiration. 12:37.010 --> 12:39.510 It becomes quite evident that 12:39.520 --> 12:42.169 this is a significant lesion or both 12:42.179 --> 12:45.059 are in that there's complete compression of 12:45.070 --> 12:46.460 the right lateral ventricle. 12:46.469 --> 12:49.289 We don't even see it and displacement of the left lateral 12:49.299 --> 12:52.109 ventricle as opposed to the 12:52.119 --> 12:53.669 acute type. 12:53.679 --> 12:56.669 We can also see the sub acute form and 12:56.679 --> 12:59.549 these are diagnosed primarily by the 12:59.719 --> 13:02.609 the secondary changes that they 13:02.619 --> 13:05.270 cause the subdural 13:05.330 --> 13:06.359 hematoma itself. 13:06.369 --> 13:09.229 In the sub acute stage has the same density as 13:09.239 --> 13:09.739 brain. 13:09.750 --> 13:11.789 So that we don't see the lesion as such, 13:11.799 --> 13:14.250 but we do see the gross displacement of the 13:14.260 --> 13:16.984 ventricular system to the 13:16.994 --> 13:18.414 contralateral side. 13:18.594 --> 13:20.955 This is a patient who we followed 13:20.965 --> 13:22.434 after surgery, 13:22.465 --> 13:24.974 she did have a left subur hematoma 13:25.224 --> 13:26.934 and following it up. 13:27.015 --> 13:28.455 Several months later, 13:28.465 --> 13:31.434 we showed the ventricles returning almost to normal 13:31.445 --> 13:32.974 and even later, 13:32.984 --> 13:34.405 the ventricles are quite normal. 13:34.414 --> 13:36.255 So that by the final examination, 13:36.325 --> 13:38.674 we had a normal scan 13:42.219 --> 13:44.960 and this is a case of a chronic subdural 13:44.969 --> 13:45.609 hematoma. 13:45.619 --> 13:46.460 Bilateral. 13:46.469 --> 13:47.479 As a matter of fact, 13:47.489 --> 13:49.030 in the frontal regions, 13:49.250 --> 13:51.929 this was picked up by means of an 13:51.940 --> 13:54.650 isotope scan and the 13:54.659 --> 13:57.409 C TT scan was carried out to confirm 13:57.690 --> 14:00.260 the findings and 14:00.270 --> 14:02.830 certainly it showed the bilateral 14:02.840 --> 14:05.429 subdurals and it saved this patient and geography. 14:05.440 --> 14:08.369 He was over 80 years old and at high risk for 14:08.380 --> 14:09.530 catheter studies, 14:12.080 --> 14:14.909 a dramatic problem that we sometimes face is a patient 14:14.919 --> 14:17.510 who suddenly loses unconsciousness 14:17.760 --> 14:20.669 and it's imperative that an accurate diagnosis be made 14:20.679 --> 14:22.219 as quickly as possible. 14:22.239 --> 14:24.510 In order to institute proper and effective treatment, 14:24.520 --> 14:26.489 can the scanner help in this type of patient? 14:27.140 --> 14:27.469 Yes. 14:27.479 --> 14:27.869 As you know, 14:27.880 --> 14:28.150 Joe, 14:28.159 --> 14:29.320 these patients are, 14:29.330 --> 14:31.309 are usually ones who have had a 14:31.320 --> 14:33.950 significant intercranial catastrophe. 14:34.210 --> 14:37.099 And it's this type of patient who has had 14:37.109 --> 14:39.599 an intracerebral hemorrhage of some kind or a 14:39.609 --> 14:40.900 stroke due to 14:41.330 --> 14:43.979 thrombosis or embolism. 14:43.989 --> 14:46.570 And it's very important that we be able to 14:46.580 --> 14:49.210 distinguish the two because the intercranial 14:49.219 --> 14:51.700 hemorrhage can will 14:51.710 --> 14:54.710 require some form of surgical therapy as opposed to 14:54.719 --> 14:57.260 the stroke where conventional medical therapy 14:57.270 --> 14:58.369 is needed. 14:58.950 --> 15:01.919 Here is an example of a young woman 15:02.450 --> 15:04.859 who developed a severe sudden headache and 15:04.869 --> 15:07.380 collapsed when she came to the hospital. 15:07.390 --> 15:10.340 A lumbar puncture was carried out and the spinal fluid was 15:10.349 --> 15:11.369 grossly bloody. 15:11.719 --> 15:14.590 We carried out an angiogram immediately on 15:14.599 --> 15:16.940 this lady and on the left side, 15:16.950 --> 15:19.520 we demonstrated a moderately large cellular 15:19.530 --> 15:22.400 aneurysm of the internal carotid artery. 15:23.799 --> 15:25.679 The right carted angiogram 15:26.190 --> 15:28.570 illustrated or demonstrated three, 15:29.210 --> 15:32.099 surprisingly an anterior communicating aneurysm 15:32.250 --> 15:35.250 and two of the right internal carotid artery 15:35.260 --> 15:38.140 at the origins of the posterior communicating and 15:38.150 --> 15:39.679 anterior choroidal vessels. 15:40.440 --> 15:43.169 In most cases of multiple aneurysms, 15:43.179 --> 15:45.320 one would expect that the 15:45.330 --> 15:47.580 larger or largest of the 15:47.590 --> 15:50.200 aneurysms will have a 15:50.210 --> 15:51.289 bled, 15:51.340 --> 15:52.260 but in this case, 15:52.270 --> 15:54.590 we couldn't be sure with four of them. 15:54.750 --> 15:57.510 So a scan was requested and carried out. 15:57.780 --> 16:00.130 And here we have a 16:00.140 --> 16:02.570 large sub frontal hematoma 16:02.659 --> 16:05.659 indicating that it was the anterior communicating 16:05.669 --> 16:08.159 artery or aneurysm that had 16:08.169 --> 16:11.119 bled and surgically, 16:11.130 --> 16:13.489 they were able to aspirate 16:13.789 --> 16:16.289 the hematoma and clip that 16:16.380 --> 16:16.890 aneurysm. 16:20.780 --> 16:23.419 This is an unfortunate illustration of a 16:23.429 --> 16:25.880 young 12 year old boy who 16:25.890 --> 16:28.150 came home from school at lunch time, 16:28.159 --> 16:31.030 not feeling very well and suddenly collapsed 16:31.039 --> 16:33.390 on his way to hospital by ambulance, 16:33.400 --> 16:35.539 he had two respiratory arrests 16:35.890 --> 16:38.849 and we carried out a scan immediately 16:38.945 --> 16:41.655 on this youngster and we demonstrated a 16:41.664 --> 16:44.414 massive hemorrhage involving the 16:44.424 --> 16:45.385 fourth ventricle, 16:45.395 --> 16:46.265 the third, 16:46.275 --> 16:47.775 the lateral ventricles, 16:47.784 --> 16:50.505 as well as a left parietal occipital 16:50.515 --> 16:52.155 intracerebral hematoma. 16:52.284 --> 16:53.455 Unfortunately, 16:53.465 --> 16:56.385 this patient died very soon after the 16:56.395 --> 16:56.994 skin. 17:00.010 --> 17:02.340 Here's another example of 17:02.869 --> 17:05.209 an intraventricular hemorrhage this time. 17:05.219 --> 17:05.719 However, 17:05.729 --> 17:08.699 in a man in his sixties who had high blood pressure, 17:08.920 --> 17:09.520 and again, 17:09.530 --> 17:12.329 we do see evidence of the intracerebral 17:12.359 --> 17:14.910 component of the bleed involving 17:14.920 --> 17:17.750 primarily the right lateral ventricle and to some 17:17.760 --> 17:19.170 degree the third ventricle. 17:19.910 --> 17:22.550 Unlike what we've all been taught in medical school where 17:22.560 --> 17:24.369 we were always told that 17:24.380 --> 17:27.270 intraventricular hemorrhage meant 17:27.280 --> 17:27.810 death. 17:28.020 --> 17:29.079 This man, 17:30.209 --> 17:31.849 this man proved us wrong. 17:32.290 --> 17:35.079 And here we 17:35.089 --> 17:37.939 have a follow up scan three weeks later and for 17:37.949 --> 17:39.209 all intents and purposes, 17:39.219 --> 17:42.150 the hemorrhage has resolved and this 17:42.160 --> 17:43.810 patient is doing quite well. 17:48.439 --> 17:51.349 Here we have a patient who has had an embolus 17:51.359 --> 17:54.079 or a thrombus with occlusion of one of the 17:54.089 --> 17:56.689 middle cerebral branches and a resultant 17:56.699 --> 17:59.420 wedge shaped zone of low density, 17:59.430 --> 18:01.770 which is very classical of an infarct. 18:02.099 --> 18:03.650 And in this instance, 18:03.660 --> 18:06.579 the patient would not have required any surgery as 18:06.589 --> 18:08.089 opposed to the others that did. 18:10.359 --> 18:11.189 Obviously, 18:11.199 --> 18:13.790 the CT scanner plays an important 18:13.800 --> 18:15.430 role in diagnosing, 18:15.439 --> 18:17.589 expanding in inter cranial lesions. 18:17.880 --> 18:20.689 And at probably a lesser risk than some of 18:20.699 --> 18:22.319 the past techniques, 18:22.329 --> 18:24.439 we have used things such as tumors, 18:24.449 --> 18:25.189 abscesses. 18:25.199 --> 18:27.660 Could you give us some examples of these 18:27.670 --> 18:28.290 problems, 18:29.280 --> 18:29.949 Joe He, 18:29.959 --> 18:32.530 here's an example of a youngster 18:32.540 --> 18:35.510 that um had a tumor. 18:35.900 --> 18:38.430 Um The scan 18:38.439 --> 18:41.319 looks so bleak and the reason it is is that this 18:41.329 --> 18:44.310 little girl was unable to hold her head straight. 18:45.020 --> 18:47.020 As soon as her head was held straight, 18:47.030 --> 18:47.989 she would vomit. 18:48.650 --> 18:51.300 And so we were still able to carry out the scan in 18:51.310 --> 18:53.260 spite of the rotation of our head. 18:53.430 --> 18:54.099 And as you know, 18:54.109 --> 18:56.810 no other examination could theoretically be 18:56.819 --> 18:58.689 carried out in this position. 18:59.040 --> 18:59.430 Here, 18:59.439 --> 19:02.000 we have the basal scan 19:02.239 --> 19:05.010 showing no significant abnormality, 19:05.020 --> 19:07.979 although we don't see 1/4 ventricle and this clued 19:07.989 --> 19:10.729 us into giving her a contrast medium and 19:10.739 --> 19:12.050 unfortunately, 19:12.069 --> 19:14.439 a high density lesion became 19:14.449 --> 19:16.939 enhanced and this turned out to be a 19:16.949 --> 19:19.349 glioma of the left cerebellar hemisphere. 19:22.869 --> 19:25.400 This is the case of a 20 or 19:25.410 --> 19:28.119 21 year old boy who complained of 19:28.130 --> 19:29.839 deafness in his left ear. 19:30.010 --> 19:32.920 This was his only problem and a scan 19:32.930 --> 19:35.839 being the least invasive of procedures to investigate 19:35.849 --> 19:38.199 deafness was carried out in our 19:38.209 --> 19:38.949 department. 19:38.979 --> 19:39.579 Again, 19:39.589 --> 19:42.530 we don't the fourth ventricle in the posterior fossa. 19:42.709 --> 19:45.390 And we therefore gave this young 19:45.400 --> 19:47.209 man contrast material. 19:47.219 --> 19:49.660 And we showed a large 19:49.670 --> 19:51.890 circumscribed tumor mass in the left 19:51.900 --> 19:53.869 cerebellopontine angle cistern. 19:53.959 --> 19:56.790 And this turned out to be a classical acoustic 19:56.800 --> 19:57.329 neuroma. 20:00.520 --> 20:03.349 This is a case to illustrate a 20:03.670 --> 20:05.829 large glioma 20:06.069 --> 20:08.369 of the left frontal lobe. 20:08.579 --> 20:11.180 And these two upper 20:11.650 --> 20:14.619 slices are prior to the contrast 20:14.630 --> 20:15.199 medium. 20:15.219 --> 20:18.010 We do see a relative high density lesion 20:18.069 --> 20:20.979 which would suggest that this is the tumor 20:20.989 --> 20:23.689 core surrounded by a lot of 20:23.699 --> 20:26.400 edema or perhaps necrosis of the surrounding 20:26.410 --> 20:26.989 brain. 20:27.280 --> 20:30.040 We then gave contrast medium and you can 20:30.050 --> 20:32.760 see that the core of the tumor 20:32.770 --> 20:34.569 becomes considerably enhanced, 20:34.579 --> 20:37.579 suggesting that the contrast medium has been 20:37.589 --> 20:40.459 able to pool in the tumor and indicating to some 20:40.469 --> 20:43.050 degree the vascularity of the lesion. 20:44.069 --> 20:46.780 This is the patient postoperatively a month or two 20:46.790 --> 20:47.400 later. 20:47.569 --> 20:50.040 And with the exception of a residual 20:50.050 --> 20:52.829 defect and presumably a surgical defect in the left 20:52.839 --> 20:53.920 frontal lobe, 20:53.930 --> 20:56.739 the tumor itself has been removed 20:56.890 --> 20:59.449 and the ventricular system is in normal 20:59.459 --> 21:00.119 position, 21:00.170 --> 21:01.599 even with enhancement, 21:01.719 --> 21:04.439 we don't show any evidence 21:04.449 --> 21:05.880 of tumor recurrence. 21:06.729 --> 21:09.640 So it illustrates the point not only of 21:09.650 --> 21:12.439 the capabilities of the scanner to show tumor 21:12.449 --> 21:15.329 but also as follow up investigations. 21:16.859 --> 21:17.079 Here, 21:17.089 --> 21:19.569 we have another case of a patient 21:20.790 --> 21:23.500 with a suspicious high density 21:23.510 --> 21:26.260 mass lesion at the level of the sanatorium on the 21:26.270 --> 21:28.579 left Conray was given. 21:28.859 --> 21:31.699 And here we have a huge 21:31.709 --> 21:34.260 homogeneously dense lesion, 21:34.329 --> 21:37.270 which is characteristic of a meningioma. 21:40.489 --> 21:43.310 This is a very interesting case of a 21:43.319 --> 21:45.699 young man who had had a mastoidectomy. 21:45.709 --> 21:48.709 One month prior to the scan had gone 21:48.719 --> 21:49.160 home. 21:49.170 --> 21:52.030 But two or three days prior to being admitted to our 21:52.040 --> 21:52.890 hospital, 21:52.900 --> 21:55.239 he developed a fever confusion 21:55.410 --> 21:57.829 and became almost 21:57.839 --> 21:58.469 comatose. 21:58.479 --> 22:01.469 By the time he was admitted here is an 22:01.479 --> 22:03.619 excellent example of a, 22:04.160 --> 22:05.459 of a fluid level. 22:05.469 --> 22:08.250 We can see gas and we can see blood below it. 22:08.520 --> 22:11.170 And this was a 22:11.180 --> 22:13.089 fairly typical abscess 22:13.280 --> 22:15.689 containing gas as well 22:15.699 --> 22:17.469 as I don't know why, 22:17.479 --> 22:20.369 but it did contain blood and this was aspirated 22:20.380 --> 22:22.890 and the young man did relatively well. 22:22.900 --> 22:25.079 We can see that initially, 22:25.089 --> 22:27.979 one might consider that this is the whole size of 22:27.989 --> 22:28.550 the abscess. 22:28.560 --> 22:31.040 But when we gave Conray a huge ring 22:31.050 --> 22:32.959 density appeared 22:33.430 --> 22:36.349 illustrating the size of the abscess in the left 22:36.359 --> 22:38.209 temporal lobe mike. 22:38.219 --> 22:41.069 It's apparent that with the advent of C TT 22:41.079 --> 22:41.859 scanning, 22:41.869 --> 22:44.810 this has revolutionized the investigation of 22:44.819 --> 22:46.339 inter cranial diseases. 22:46.359 --> 22:48.709 Do you think you might give us a brief summary of some of its 22:48.729 --> 22:49.770 advantages? 22:50.319 --> 22:50.719 Sure, 22:50.729 --> 22:51.140 Joe, 22:52.000 --> 22:53.969 first and foremost, 22:53.979 --> 22:56.959 it's essentially a non invasive examination. 22:58.180 --> 22:58.969 Certainly, 22:58.979 --> 23:01.910 we may have to give contrast medium and we do 23:01.920 --> 23:04.890 so in perhaps 60 to 70% of cases. 23:04.900 --> 23:07.459 But we don't consider the injection of contrast 23:07.469 --> 23:10.390 medium an invasive procedure as such. 23:10.819 --> 23:13.000 But it does have the 23:13.010 --> 23:15.660 advantage of providing us with so much 23:15.670 --> 23:17.630 information that 23:18.219 --> 23:20.310 plain skull examinations, 23:20.319 --> 23:21.060 skull, 23:21.329 --> 23:21.780 sorry, 23:21.790 --> 23:24.250 angiograms and pneumoencephalogram don't, 23:24.660 --> 23:25.410 in fact, 23:25.420 --> 23:28.050 it's done away with many of the 23:28.060 --> 23:30.540 invasive procedures that we carried out in the 23:30.550 --> 23:31.109 past, 23:31.560 --> 23:34.280 the accuracy is in the 90 to 23:34.290 --> 23:35.780 98% range. 23:35.790 --> 23:38.760 And this has been shown in many papers 23:38.770 --> 23:40.780 that have been written in the past few years. 23:41.260 --> 23:44.199 Scanning allows us to assess the subarachnoid 23:44.209 --> 23:46.329 spaces and the ventricular system. 23:46.459 --> 23:47.369 And as you know, 23:47.380 --> 23:48.020 in the past, 23:48.030 --> 23:50.479 only the injection of air or 23:50.489 --> 23:52.430 contrast medium into the 23:53.819 --> 23:56.410 into the CSF pathway system 23:56.550 --> 23:59.290 would have allowed us to assess the spinal 23:59.300 --> 24:00.420 fluid pathways. 24:00.869 --> 24:03.839 Uh It's certainly uh a great advantage in 24:03.849 --> 24:06.219 the assessment of trauma patients and in 24:06.229 --> 24:07.380 not, 24:07.790 --> 24:10.140 uh and not uncommonly saves us doing a 24:10.209 --> 24:11.040 geography. 24:13.140 --> 24:13.969 As you know, 24:13.979 --> 24:15.270 as we've discussed, 24:15.280 --> 24:18.160 it's tremendous in assessing the patient who 24:18.170 --> 24:21.160 has become suddenly unconscious and particularly 24:21.170 --> 24:23.380 to see if this patient has had an 24:23.390 --> 24:24.910 intracerebral hemorrhage, 24:24.920 --> 24:27.130 which would require aspiration. 24:29.239 --> 24:32.130 The the scanner allows us 24:32.140 --> 24:34.969 to carry out serial studies either 24:34.979 --> 24:37.349 post operatively or just post 24:37.359 --> 24:39.589 treatment and we can follow 24:39.599 --> 24:41.849 patients weekly, 24:41.859 --> 24:42.650 daily, 24:42.660 --> 24:43.930 monthly or yearly. 24:43.939 --> 24:45.020 It really doesn't matter, 24:45.030 --> 24:47.369 but it is a way of assessing the patient. 24:47.380 --> 24:48.739 Once we have a baseline. 24:49.150 --> 24:51.609 As we noted very early in the 24:51.619 --> 24:52.569 program, 24:52.579 --> 24:54.599 the scanner is capable 24:54.609 --> 24:57.520 of allowing assessment of 24:57.530 --> 25:00.280 the orbit and the eye and the optic nerves. 25:00.290 --> 25:03.079 And we have picked up a number of tumors and there have been 25:03.089 --> 25:06.060 reports of many ophthalmologic 25:06.069 --> 25:08.660 lesions being picked up by other 25:08.670 --> 25:09.780 institutions. 25:10.060 --> 25:10.599 Of course, 25:10.609 --> 25:11.400 economically, 25:11.410 --> 25:14.079 it's a tremendous advantage in that we are 25:14.089 --> 25:16.630 now saving admission of patients to 25:16.640 --> 25:18.859 hospital for investigation of 25:18.869 --> 25:21.839 their possible brain 25:21.849 --> 25:22.780 lesions. 25:22.790 --> 25:25.439 We save perhaps three or four days of hospital 25:25.449 --> 25:28.079 admission and we also 25:28.089 --> 25:31.010 save the patient having to undergo a geography 25:31.020 --> 25:32.589 or pneumoencephalography. 25:33.689 --> 25:36.689 There are perhaps a few disadvantages in 25:36.699 --> 25:39.119 that it is a relatively time consuming 25:39.130 --> 25:41.689 procedure which requires if we give 25:41.699 --> 25:42.859 contrast medium, 25:42.949 --> 25:45.420 probably a total of an hour, 25:45.430 --> 25:48.040 which limits us in doing perhaps a 25:48.050 --> 25:50.930 maximum of 10 to 11 patients in any 25:50.939 --> 25:52.130 10 hour day. 25:52.439 --> 25:54.680 The other thing of course is that it requires a 25:54.689 --> 25:57.670 maximum immobilization and 25:57.680 --> 25:58.609 without it, 25:58.880 --> 26:01.109 the patient can move around. 26:01.290 --> 26:04.060 And so we therefore just might have to 26:04.069 --> 26:06.869 sedate the patient or give 26:06.880 --> 26:08.390 him a general anesthetic. 26:08.540 --> 26:11.390 But I think you can see from all of the 26:11.400 --> 26:13.560 cases we presented that these 26:13.569 --> 26:16.040 disadvantages are far outweighed by the 26:16.050 --> 26:18.109 capabilities and the advantages 26:18.119 --> 26:20.709 of the CT scanner. 26:22.569 --> 26:25.489 If you're interested in participating in the evaluation of the 26:25.500 --> 26:26.229 health care today, 26:26.239 --> 26:28.689 television programs or if you would like further 26:28.699 --> 26:31.099 information on the program's planned for this year, 26:31.109 --> 26:34.099 please contact the program coordinator health care 26:34.109 --> 26:34.839 today. 26:34.849 --> 26:37.609 Room one R one Faculty of 26:37.619 --> 26:40.209 Health Sciences mcmaster University, 26:40.219 --> 26:41.479 Hamilton Ontario 26:46.130 --> 26:46.849 Health Care. 26:46.859 --> 26:48.959 Today was produced in cooperation with 26:49.750 --> 26:50.339 TB, 26:50.500 --> 26:53.319 the Faculty of Health Sciences mcmaster University, 26:53.500 --> 26:55.599 the Ontario Medical Association, 26:55.640 --> 26:57.060 Mohawk College, 26:57.069 --> 26:59.760 the Ontario Chapter of the Canadian College of Family 26:59.770 --> 27:02.699 Physicians and the Hamilton Academy of Medicine.