----start--- medsurg3 11/5/98 Dr Wortman? seems like no one introduces him/her self anymore. The handout is complete There is a list of reading in the handout. He has the texts on display up front. Dr Owen's black Purina paperback is "the minimum you should go through." It has recently been updated by Biery/Owen and is available in hardback. Diagnostic Radiology of the Dog and Cat Canine and Feline Gastroenterology Textbook of Veterinary Diagnostic Radiology Radiographic Diagnosis of Abdominal Disorders in the Dog and Cat - the bible of abdominal radiography; no longer in print Please start looking at radiographs Radiology is under renovation right now; getting two new diagnostic rooms and a CT scanner. His office is on the fourth floor, feel free to see him, email him, whatever. you can look at the rads over the weekend. today we will go over principles of interpretaton of radiographs, use some case examples, etc. most of the rest of the lecture will be more focused. Abdominal Radiography: radiographic interpretation - principles: -know radiographic anatomy -use systematic examination method -know radiographic signs of diseases -know disease incidences -correlate radiographic findings with other clinical data. systematic method of exam: -evaluate quality of the study [slide] normal abdominal rad: is it straight? are legs in the way? is it rotated? is the whole abdomen included from tip of diaphragm to hips? judge exposure - background should be black. look at spine - for abd, should be slightly underexposed for good abdominal technique. -use thorough search method - no one way for this. just do it same way each time. don't overinterpret the film to make it fit what you think is going on; don't focus too soon on an obvious abnormality. look at the whole thing. he likes to do it systematically - diaphragm, liver, spleen, GIT, urogenital. -determine anatomic location: need two views to do this. -enumerate radiographic signs: size, shape, location, opacity, number, function. -establish a radiographic diagnosis: -differential diagnoses -focused search so you go through the search in systematic way, look at the radiographic signs, and then come up with a radiographic diagnosis. from that, come up with list of clinical differential diagnoses. then you can start a focused search. Gamut: list of diseases that may result in the production of a "radiographic sign". as you identify more signs, some diseases fall off the list. if you find something that is enlarged, say a kidney, then many things cause that, but if you find it is large and misshapen, things that cause enlargement without shape change fall off the list. slides: two lateral abdominal rads, both cats. both abnormal. both have increased opacity, abdominal distension, poor abdominal detail. that is the radiographic feature these have in common. poor intraperitoneal detail: -lack of normal fat: immature animals (brown fat has soft tissue density), emaciation, steatitis -peritoneal effusion: transudate, exudate, blood, urine -carcinomatotis: -abdominal masses: Differential diagnoses: DAMNIT - this is what you mutter when you are asked in clinic rounds to list the ddx for your patient. DAMN IT, DAMN IT! you can repeat it twice. developmental, degenerative anomolous, autoimmune, artifactual metabolic, mechanical neoplastic nutritional infectious inflammatory traumatic, toxic additional principles: you should be able to: develop a list of rule outs for specific radiographic signs describe the expected radiographic signs for various disease do focused search based on this knowledge Poor intraperitoneal detail focused search: -recheck radiographic technique -abdominal distension present? -serosal detail -abdominal wall detail -organ displacement -extraabdominal findings slide: that cat rad again technique isn't so good. the background is black. if anything, the spine is overexposed, so it is really overexposed - so this isn't the problem. the technique isn't optimal but isn't making this loss of detail. the abdomen is distended. there is some gas in stomach. we can't see any detail here - we can see some in caudal abdomen where we see some small bowel loops - organ displacement and mass, most likely. any idea what that mass was? it was a perinephric pseudocyst! the other cat rad: this one has good technique. the abdomen is distended, we see stomacha nd some liver. there is poor detail in midabdomen. we see colon, we see kidneys. there's extensive loss of detail involving most of the cavity. there is no obvious organ displacement. radiographic dx = peritoneal effusion. could be transudate, exudate, hemorrhage, urine. looking at the rad doesn't really allow us to tell those apart. but we see some fluid present in the pleural cavity as well. so whatever this animal has it has fluid in chest and abdomen.this cat has FIP. correlate findings with clinical data: signalment history signs PE lab data other imaging studies slide: rads with magic marker outlines of all organs there are diagrams like this in the handout. expect to see: liver, sometimes edges of lobes stomach (left lateral puts air in the pyloric antrum) colon - depending on content one or both kidneys (right in front of left) urinary bladder - depending on if full or empty prostate small bowel do not expect to see pancreas, gall bladder, LNs, adrenal glands unless they are abdnormal on VD: fundus of stomach on left, look for same stuff. Liver/gall bladder/pancreas/spleen we do not normally see gall bladder and pancreas. liver is in cranial abdomen - usually seen ventrally, extending to about the costal arch, if going past that, enlarged. on VD we do not see the lobes; it's still in cranial abdomen. it isn't in left dorsal cranial abdomen- stomach is there. normal spleen - sometimes we see dorsal part, more often we see thele - tail ventrally. position variable from in contact with liver to in contact with bladder. on VD we see it as a triangle b/w stomach and left kidney. caudal and lateral to fundus of stomach; cranial and lateral to cranial pole of left kidney. we can use the location of the stomach to assess liver size. in dogs there is some normal variation in stomach size/shape. deep chested dogs and also in cats, stomach axis is roughly parallel to ribs - usually stomach is at 10 or 11th intercostal space. stomach is roughly perpendicular to axis of ribs on VD. slide: in cat, stomach is mainly on left side, kind of J shaped, with antrum roughly midline. in dog, antrum usually midway b/w spine and right body wall, more U shaped. slides: two dog abdomens. increased opacity, abdominal distension seen in both rads. both are liver enlargement. we see some air in stomach dorsally, and stomach axis is displaced dorsally and caudally on one rad; on the other we see stomach dorsally and perhaps pushed caudally. we see what appears to be soft tissue structure pushing caudally from area of the liver. VD rad - we cant see fundus, but we see part of stomach...we see mass is in right cranial abdomen. on lateral, we see it is a ventral mass, so it isn't kidney. also we can see the kidney - uh, no we can't, but whatever. he can see it. i see plain white space. hepatomegaly, localized (to one lobe): hyperplasia, neoplasia (esp primary), hematoma, abscess, granuloma, cyst, torsion hepatomegaly, generalized: hyperplasia neoplasia (esp LSA, secondary), inflammation (acute hepatitis), vascular stasis (RHF), biliary stasis, lipidosis (obesity, d.mellitus, cushings, hypothyroid), storage disease (mps), drugs, toxins. hepatic ultrasound: understand how this is complementary to radiography indications: -parenchymal disease -gall bladder and biliary disease -vascular abnormalities normal u/s appearance of liver: remember - white = echodense, black = anechoic (white) bone, gas, fibrous tissue, fat, spleen, liver, kidney, fluid (black) the liver is: isoechoic or hyperechoic to right kidney - compare caudate lobe to right kidney. left lobe is hypoechoic to spleen coarse texture compared to spleen hyperechoic portal vein walls diffuse lesions: hypoechoic -passive congestion -hepatitis, cholangiohepatitis -neoplasia - lymphosarcoma diffuse lesions: hyperechoic: -fatty change (DM, cushings, hypothyroid, obese) -cirrhosis -chronic active hepatitis with fibrosis -neoplasia that's general, but LSA could cause hyperechoic or nodular changes, too, so you can't use this as an absolute rule, more of a guideline. focal lesions: anechoic -cysts: this is pretty specific - tissues deep to the cyst have increased echogenicity due to "acoustic enhancement" focal lesions: mixed echoic abscesses extramedullary hematopoiesis granuloma, hematoma, neoplasia, nodular hyperplasia these are all nonspecific, but u/s is very sensitive slide: lat abd of fairly big dog. increased opacity in cranial abdomen; blurred or rounded edge to liver. not nice and sharp. u/s of same dog: there is an area with some internal echo - speckled - so there is some stuff in there, this can't be a cyst - but it is very hypoechoic except for the speckles. there is no acoustic enhancement. the rest of the tissue is abnormal - this is a primary liver tumor with a large necrotic central portion. this isn't a specific finding. you need clinical information and lab data to know what it is. slide: u/s of cranial abdomen - we see diaphragm with heart in front of it and liver behind it. in the liver is a focal area of hypoechoic tissue with a central area that is hyperechoic. this is a "target lesion" which is fairly specific but not pathognomonic for a metastatic site within the liver. small liver - microhepatica -cirrhosis -portal vascular anomaly -necrosis -(hernia)(liver isn't really small, just looks small b/c most is in chest) you should normally have liver keeping stomach in place. big liver caudally displaces antrum. small liver allows cranial deviation of antrum. rads: this small dog has a small liver. ventrally we see a soft tissue density structure that could be large liver or tail of spleen. look at stomach - is under left crus of diaphragm. the antrum is very far ventral/cranial. this means liver is small and the other thing is spleen. on VD we see the head of the spleen, feces in the colon, and we see transverse colon way more cranial than normal. this also supports finding of small liver. portal venography: in young animals, we'd first consider portovascular shunts as a cause of microhepatica. we could do radiographic contrast study to confirm. sites of injection: mesenteric vein - requires laparotomy cranial mesenteric artery - requires laparotomy or can be done by femoral a catheterization coeliac artery (celiac artery) spleen - can just inject into it. ---break--- slide; normal portogram - cranial mesenteric arteriogram, serial rads were taken, fluoroscopy was used, etc. uses special equipment. there is contrast going through portal vein and arborization of portal vasculature is obvious. slide:normal portogram: 6 seconds post injection: mesenteric arterial phase of study - vascular supply to small bowel is highlighted. four seconds later: now that is all fuzzy, contrast is in veins of bowel. four seconds after that - contrast is in portal vein, and it goes straight through, directly into caudal vena cava - patent ductus venosus is present. in private practice if you want to do this you probably do operative mesenteric venogram. you isolate bowel loop, put cath into a mesenteric vessel, make your injection, take a couple of films at the appropriate time. slide; operative mesenteric venogram - we see forceps in place, and we see contrast going via aberrant vessel into the azygous vein. porto-azygous shunt. shunts can even go way back into the back of the abdomen. it is hard to know where it is going to go before hand. slide: ultrasound shunt hunt. u/s is good b/c of doppler, can identify direction of flow and stuff. can be frustrating and time consuming to do this though. slide - the same nuclear scintigraphy slides that Dr Brockman showed us the other day :) remember - enema of isotope, etc. i won't write this up again... the point is that normally the liver lights up before the heart, and in the presence of the shunt, the heart shows up first. after you do this study you could then do a venogram or arteriogram, or go directly to surgery if you have a crack surgeon. changes in radiographic opacity of liver: slide: multifocal white spots throughout liver. multiple areas of increased opacity that are in the region of the liver - these are granulomas with mineralization. this is a very rare finding. another type of change we see is increased lucency in the liver - also rare, maybe a bit more common than opacity. could be due to air embolus - portal tree will be lucent, radiolucent arborization - this would be fatal. or air in liver if there is a gas forming bacteria in there - some anaerobe, or if in a diabetic animal there is excess sugar, sometimes gas filled abscess forms. slides: contrast in the stomach but really there is also contrast filling the gall bladder - this is to remind you where gall bladder is. rarely, we see radioopaque choleliths - usually incidental finding in an animal with no signs of gall bladder disease. sometimes you may see emphysematous cholecystitis. you need to know where the gall bladder is so you if you see a problem in it you know it is in gall bladder, not liver. Spleen: main changes we see are in size; rarely in opacity; occasionally in location. splenomegaly: generalized - diffuse drugs - barbiturates, some tranquilizers vascular stasis neoplasia chronic hemolytic anemia some dogs just seem to have big spleens, too. splenomegaly - localized -neoplasia -hematoma -nodular hyperplasia -abscess/infarct lat abd rad - large dog - midabdominal mass - probably a splenic mass. looks like a big softball or something. it's in ventral abdomen. there are also urinary calculi present. the spleen turned out ot have a large nodular round hemangiosarcoma within it. lat and vd of another large dog. ther eis air in the stomach, the stomach axis is abnormal - think small liver or big spleen or other mass caudal to stomach. we see poorly defined mass in cranial abdomen, caudal to stomach. on VD we see cranial pole of left kidney, and a mass occupying space b/w stomach and kidney - likely a splenic mass. this was a benign hemangioma. slide; a soft tissue opacity in cranial ventral abdomen. air is in stomach, stomach axis again cranially displaced, on VD instead of seeing spleen where we expect it we see small bowel loops. we see left kidney caudally displaced. we also see a loop of bowel - duodenum - displaced medially coming down right side, and there is a big triangular soft tissue density along right body wall - this is splenic torsion. spleen is on wrong side here. you'd take this dog to surgery. at surgery we see the spleen is enlarged, engorged. over time would get necrotic. prior to necrosis, animal shows vague signs of pain, inappetance. retrospective studies show that this can be present weeks/mos prior to diagnosiss. normal spleen ultrasonic appearance: hyperechoic to left liver lobes very hyperechoic to left kidney fine texture compared to more coarse liver multiple splenic veins, hilar border diffuse changes: usually result in hypoechoic appearance -active/passive congestion -hemolytic/parasitic anemia -neoplasia -splenic torsion focal lesions - easier to find, not specific. mixed echoic -abscesses -extramedullary hematopoiesis -hematomas -hyperplasia -infarctions -neoplasia we can make mistakes. if we see focal lesions in liver and spleen we usually think metastatic dz, but sometimes it is nodular hyperplasia in both, unrelated to each other. so you have to biopsy it. another large dog - 9 yr old GRET. cranial abdomen cloudy, distended. we see some of liver edge indistinctly, poorly defined focal area in midabdomen with caudal displacement of small bowel. mass is present - on u/s heteroechoic, several cm length mass in spleen - hemangiosarcoma. another dog - 6 yr old GSD - spleen has multiple hypoechoic regions, and a large anechoic/speckled region - that's hemorrhage in the abdomen outlining the spleen - this is also hemangiosarcoma. this is a commen presentation. spleen - mixed echogenicity - some dark, some light areas. this is a hematoma. he was owned by large animal vet, got kicked by a large animal. pancreas: anatomic landmarks: right limb - medial to descending duodenum, ventral to right kidney body: ventral to portal vein, caudomedial to pylorus left limb; caudal to stomach, ventral to caudate lobe, portal vein, CVC, aorta; craniodorsal to transverse colon, terminates craniomedial to left kidney slide: cat abdomen, lat view. stomach axis is cranially displaced. there is a soft tissue opacity caudal to the stomach. this looks like the splenic masses. but, it is probably pancreas since we are talking about pancreas. on VD, we see the mass is in midabdomen, and we see spleen over in normal location. this mass is caudal to stomach in cranial abdomen, slightly right of midline. this cat showed signs of pancreatic dz, so probably this is in fact the pancreas and it was, a pancreatic carcinoma in 15 yr old cat. radiographic signs of APN: dr washabau already gave us these but anyway: increased opacity, decreased contrast in right cranial quadrant: 58% left gastric displacement, antral truncation: 55% right duodenal displacement, medial "mass": 42% dilated gas filled descending duodenum: 25% dilated gas filled tranverse colon +/- caudal displacement: 9% this is from a study from 1978 of 120 or so dogs with pancreatitis. JAVRS 19:102, 1978; Kleine and Hornbuckle note an animal with pancreatitis could have all or none or one or a few of these signs. you have to correlate any radiographic findings with clinical and other findings. animals with pancreatitis do usually have an empty stomach - that wasn't in this study though. if animals are vomiting or not eating, stomach should be empty. this VD radiograph shows an ill defined area of increased opacity in the right cranial quadrant of the abdomen. this is another animal - if you're unsure what's happening, you can do a contrast study - now you can see what's going on better. here we see duodenum looks really thin, and looks compressed by a mass. that's the pancreas of the animal with ill defined area of increased opacity on plain film. another animal - possible mass in cranial right quadrant, also loss of detail in mid abdomen. on lat rads we see gas filled bowel separated by poorly defined area of increased opacity which is acting like a mass. u/s of this - we see duodenum and adjacent to it is an area that is irregular, hypoechoic, surrounded by hyperechogenicity - edema in pancreas makes it hypoechoic, surrounded by hyperechoic inflammatory response. note also that when you press with probe to get a good image, animal will have a pain response. this u/s from another dog has similar appearance to other dog - irreg hypoechoic structure in area of pancreas, slightly less hyperechoic area around it. this was pancreatic adenocarcinoma. so there is a lack of tissue specificity. canine insulinoma: hypoechoic to surrounding tissue well defined margins hypoechoic liver mets often these are very small tumors although we've gotten better at finding them. slide: nice u/s - we see duodenum and then a well defined hypoechoic mass adjacent to duodenum in animal with low blood glucose. highly suggestive of insulinoma. radiographic evaluation of the esophagus: survey films contrast esophogram the changes we see in the esophagus are good models for what we see in stomach, other parts of GIT, but are much easier to see. so we'll start with the esophagus to go over this stuff. esophagram: opacification of the esophagus with positive contrast material. there are several types of contrast to choose from - premixed liquid barium, paste barium, or iodinated contrast if you suspect perforation. mucosal detail: barium paste is best - will adhere to mucosa integrity: barium liquid motility: fluoroscopy, serial rads volume: may require barium mixed with food slide: normal esophogram - looks like striped ribbony thing b/c in dog there are longitudinal folds in the esophagus. slide: another normal canine esophagram - bolus is at base of heart. another film right after that would probably show the bolus in the stomach. so you have to take multiple films. if you take another film and it hasn't moved, maybe there is a stricture. slide: esophagram in cat - we know it is a cat b/c there are circular stripes, not longitudinal ones. sometimes called a herringbone pattern. this is in the caudal thoracic esophagus. i see nothing remotely resembling that description on this slide. slide: gross specimen - circular ridges in caudal feline esophagus. this i do see :) signs of esophageal disease (radiographic) -opacity increased or decreased -size: -position -function changes in these can indicate disease filling defects: can be intraluminal, intramural, or extrinsic. intraluminal: foreign body intramural: esophageal neoplasia like leiomyoma extrinsic: big lymph node those are just some examples normal esophagus is not usually seen on survey rads, unless it contains air or fluid. sometimes we see it full of air. if you do, you should figure out if that is a sign of disease or not. it is often, but not always. if an animal struggles during radiography or has respiratory distress, may have swallowed air. during anesthesia may get air in there during esoph steth placement. sometimes we see fluid in caudal esophagus as in this animal that is otherwise normal - note caudal vena cava, and then poorly defined stripe of increased opacity above that - probably some fluid in esophagus. that may be normal. slide: dog that came in with regurgitation, dysphagia - we see tiny round opacities like bbs which are present in the neck -also swelling of the neck cranial to those. dorsal to trachea are areas of radiolucency. there is also an area of induration and scarring near the BBs. contrast study: some distension of cranial esophagus, then contrast sort of stops flowing in one area, then continues more normally. also there is irregular diameter of trachea near the induration of the skin, with fibrous adhesions of neck injury causing constriction of trachea and esophagus. this dog is good candidate for balloon dilation of esophagus. ---end---