Photo Album PDF

# Photo Album ## by wisam neriman # What is contrast? - Synonims of contrast: distinction, dissimilarity, variance. - The contrast ratio is the ratio between the luminance of the brightest white and the darkest black that a TV can produce. Larger contrast ratios work out to deeper blacks, which mak...

# Photo Album ## by wisam neriman # What is contrast? - Synonims of contrast: distinction, dissimilarity, variance. - The contrast ratio is the ratio between the luminance of the brightest white and the darkest black that a TV can produce. Larger contrast ratios work out to deeper blacks, which make a big difference to overall picture quality. - Modern OLED panel has an infinity:1 contrast ratio. Source: https://www.rtings.com/tv/tests/picture-quality/contrast-ratio # When are contrast media not necessary? # Why do we use contrast media? 1. To increase the contrast between the organ of interest and its surroundings. # A few words on x-ray imaging - When describing x-ray images, we talk about increase or decrease of transparency. - Air and fat show increased transparency, for instance. - Bones, metals and contrast media show a decrease of transparency. # A few words on CT imaging - At CT we talk about increase and decrease in density. - Air and fat are less dense (hypodens) than bones, metals and contrast media, which are hyperdens. # X-ray Contrast Media 1. **Positive** (Ba-sulfate, iodine) - elements with high atomic numbers that have good x-ray attenuating capabilities. 2. **Negative** (air, CO₂, metylcellulose-solution, water) – these materials attenuate x-ray photons to a lesser degree than surrounding organs. We use them in single or double-contrast studies. **What do they produce?** A difference in transparency (x-ray) or density (CT). # Why do we use contrast media? 1. 2. Contrast dynamics might be diagnostic. # Negative contrast media # Barium-sulfate (Micropaque) - „Barium meal” 1. It is insoluble, thus it is not toxic to ingest. 2. GIT studies (mono: dilute solution; double-contrast: thicker solution + gas forming powder). 3. Introduction: per os, per rectim. 4. In case of bowel perforation it can cause peritonitist! It will initiate a foreign body reaction: fibrin production + ascites. 5. If aspirated it can cause pneumonia. 6. Side effect: diarrhoea 7. It clears the bowels in 2-3 days 8. Contraindication: pregnancy, perforation, complete bowel obstruction **Alternative:** Gastrografin. If bowel perforation is suspected, this contrast material can be safely given to the patient. It is iodine based. # Iodine containing contrast media 1. **Lipophilic** - cholecystography, cholangiography. - Cholecystography: it is outdated. Instead, we use ultrasound to diagnose bile stones. Oraly given contrast media accumulates in the gall bladder; bile stones will show up as transparent areas against white background on the abdominal x-ray. - Cholangiography is used for instance if ERCP is not possible to carry out (after Billroth II. surgery). We insert a needle into the bile ducts under ultrasonic guidance. Thus we can visualize obstruction, and even treat it by removing a bile stone or dilating a narrow segment for example. 2. **Hidrophilic** – tri-iodine benzol ring based + side chains - **Ionic:** carboxyl chain (Telebrix, Hexabrix) - **Non-ionic:** hidroxyl side chain. These do not dissociate in water (Omnipaque, Optiray, Ultravist, Xenetix, Visipaque) - If administered intravenously, these will clear the body through the kidneys. Images: we used these contrast media during i.v. urography, CT-studies, angiography, and GIT studies if perforation is suspected. # Side effects of iodine containing CM (mild/serious): ## Osmotic: - There are CM with low and high osmolarity, and there are isoosmolar molecules. - Osmotic stress will cause deformation of the RBC, which in turn may caule thrombosis. ## Chemotoxic (histamin, complement activity) - NAUSEA, VOMITING - vagotonia - RR↓, TC/BC, ARRHYTHMIA - CONVULSION ## THYREOTOXIC CRISIS- May occur in patients with pre-existing thyroid disease and through complications of thyrotoxicosis. # Side effects of iodine containing contrast media 1. Usually mild, but death may occur even if a non-ionic medium is used. 2. Most common: nausea, vomiting, erythema, pain and warmness. 3. Other: sweating, urticaria, coughing, dry mouth, itching, hypotension, convulsion → these should be taken very seriously because they may be signs of an imminent anaphylactic reaction. ## WHAT SHOULD WE DO? 1. Urticaria (hives), dermography - overwatch, antihistamin 2. + hypotension, dyspnoe - CALL 911, oxigen, bronchodilator, adrenalin (1/100) 3. + bronchospasm - adrenalin (1/10) 4. Cardiac and respiratory arrest - adrenalin undiluted. After CT all patients are monitored for 30 minutes. There must be an emergency medical team in the hospital! # Metformin and company - Metformin is a biguanid type oral anti-diabetic drug - Virtually all patients with type II. diabetes use some form of metformin containing drug at some point in their lives. - Generics of metformin are common with over 20 different drugs in Hungary. - The presence of metformin cannot be safely inferred from the name of the drug (pl. Eucreas, Competact, Velmetia) - Impaired renal function is quite common in diabetic patients due to the underlying disease. - Iodine-containing CM may further impair renal function - temporarily! - Metformin completely clears through the kidney - If renal function is impaired, metformin will accumulate in the body - Metformin elevates serum lactate levels, thus it can cause lactic acidosis # Alternative CM - 30 mg prednisolon can be given 12h and 2h prior to the study # What type of medication is the patient on? ## Questions (yes-no): - Have you ever received any contrast media? - If yes, did you experience any side-effects? - Do you have an allergy that requires treatment? - Have you been diagnosed with asthma? - Hyperthyreosis? - Cardiac failure? - Diabetes ? - Have you been diagnosed with nephropathy? - Have you had kidney surgery? - Have you been diagnosed with proteinuria? - Do you have hypertension? - Do you have gout? - EGFR/Se-creatinin level: ______ - Do you take any of the following medication? - Metformin - Interleukin2 - NSAID - Aminoglicosid antibiotic - Beta-blocker - Patients who are allergic to fish, oyster, cats/dogs, dust, etc. are not allergic to CM - Betadine- the carrying molecule is what patients are allergic to - Hyperthyreosis is an absolute contraindication of administration of iodine-containing CM! # What is lactic acidosis? 1. It is serious, life threatening metabolic syndrome in diabetic patients 2. It is the accumulation of lactate in the serum and the associated acidosis - Blood pH ≤ 7.25, Se- lactate level : ≥ 5 mmol/l 3. Symptoms: gastrointestinal at the beginning (nausea, vomitting, diarrhea), later muscle pain and spams, hyperventillation, sleepiness, confusion and then coma. 4. Treatment: alcalisation (bicarbonate- infusion) and removal of lactate from the blood (dialysis) 5. Mortality: almost 50% 6. It is hard to treat, thus we must avoid it! # Further contraindications 1. Manifest hyperthyreosis: profilaxis may be used, but the endocrinologist should be notified. 2. Myeloma multiplex: the paraprotein gets stuck in the tubules - excretion is further damaged. 3. Phaeochromocytoma: hypertension crisis; alfa + beta adrenerg blockers should be given prior to the examination 4. Pregnancy: contraindicated # ESUR recommendation 1. All patients on metformin should be identified prior to the examination. 2. Based on renal function, administration of metformin should be stopped on the day of the examination or 48 hours prior to it. 3. If the estimated glomerular filtration rate (eGFR) is greater than 60 ml/min/1.73m², or the Se-creatinin is normal, its enough to stop administration of metformin on the day of the exam. 4. If the eGFR is between 30-60 ml/min/1.73 m² or the serum- creatinin level is elevated, the administration of metformin should be stopped 48 hours prior to the study and it should not be given back earlier than 48 hours after the study, but only if the serum-creatinin level rises. 5. If the eGFR is less than 30 ml/min/1.73 m², metformin is contraindicated anyway, and any iodine-containing contrast media should be avoided. # What is lactic acidosis? 1. It is serious, life threatening metabolic syndrome in diabetic patients 2. It is the accumulation of lactate in the serum and the associated acidosis - Blood pH ≤ 7.25, Se- lactate level : ≥ 5 mmol/l 3. Symptoms: gastrointestinal at the beginning (nausea, vomitting, diarrhea), later muscle pain and spams, hyperventillation, sleepiness, confusion and then coma. 4. Treatment: alcalisation (bicarbonate- infusion) and removal of lactate from the blood (dialysis) 5. Mortality: almost 50% 6. It is hard to treat, thus we must avoid it! # MR contrast media 1. Diamagnetic 2. Paramagnetic 3. Superparamagnetic - Mostly superparamagnetic and paramagnetic CM are used for MR imaging - Paramagnetic media act as positive contrast by lowering the T1 relaxation time, while superparamagnetic agents are negative contrast media that act by lowering the T2 relaxation time. # Iron-oxide — superparamagnetic CM - There are two types of iron-oxide CM, that superparamagnetic iron-oxid (SPIO), and the ultra small superparamagnetic iron-oxid (USPIO). - These exist as iron-oxid nano particles and lower the T2 signal of the organs that accumulate them. - SPIO and USPIO CM have been successfully used for liver cancer imaging, and cervical lymph node imaging (MR lymphography). - Cancerous cells do not accumulate iron-oxide, however, cells of the reticulo-endothelial system (in normal cells) do! # Lipiodol 1. Poppyseed oil + iodine 2. It is the most sensitive CM for HCC 3. It is also used for chemoembolisation 4. Images: iodine based angiography (top image) and CT (middle image) both confirm the lesion in segment VIII. of the liver, however only the lipiodol study (bottom image) shows the second lesion in segment VII. # Pregnancy and breast feeding | | Iodine-containing CM | Gd-lodine-containing CM | |---------------|-------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Pregnancy | (a) Rarely, if necessary, pregnant women may receive iodine-containing CM. | (a) Rarely, if necessary the smallest amount and most stable Gd-containing CM can be given. | | | (b) If this happens, the thyroid furetion of the newborn baby should be checked 1 week after birth. | (b) The newborn does not need to be checked if the mother recived Gd-containing CM. | | Breast feeding | Breast feeding can be continued after administration of iodine-containing CM. | Breast feeding should be stopped for 24 hours if a less stable compund was used. | | | No further action should be done for the baby. | Do not give Gd-containing CM! | | | Pregnant or breast feeding woman who also has impaired renal function. | | # Ultrasonic CM (SonoVue) 1. These are present as microbubbles within the vessel 2. The ultrasound wave bounces back from the bubbles and increases in power. 3. They are mainly used in the diagnosis of focal liver lesioins - circulation dinamics -DDX + kidney. 4. Needed: special software + proper US machine 5. Sulfur-hexafluoride gas + phospholipid shell 6. Diameter: 2-3 micron (smaller than the RBCs)- they pass through pulmonary capillary bed 7. They stay in the circulation and exit though the lungs; thus they may be used in case of renal impairment (2-4 ml iv. bolus).