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Radiology for Finals

By Shane Torres,2014-06-26 21:13
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Radiology for Finals ...

Radiology for Finals th(Updated: 7 April 2006) - Highly likely that will get asked about images in long/short cases in finals - May be asked to quickly comment on any abnormality or to present in full a radiograph. - It is all about systematic approach in order to check that we are safe on the wards as JHO’s. Don’t panic if the diagnosis is not obvious. Being able to spot abnormalities and comment that you need to ask for help from a radiologist is the important part. - If you know a little bit extra it is a good way to impress the examiners. - Remember physicians/surgeons are not radiologists so going to ask about the big classical signs. - Plain films are likely to figure most highly, although particularly significant other images may occur. - If the patient has a series of films get the right one and the right patient. - Unlikely to give anything that is not a big complaint/classic radiological sign. It may be NORMAL. - Imaging is likely to feature highly in most patient management. Therefore think of it when asked, ‘ how would you manage/investigate this patient?’ I will also try to link the images to the appropriate cases contained within the Pastest Medical & Surgical Finals books (Below). Range of Films May Come Across (* greatest chance of being asked to comment on or know) Respiratory *Bronchial CA (+ Pancoast’s) Pulmonary metastases *Pneumonia (several lobar, bronchopneumonia and PCP) !! Bronchiectasis/Cystic fibrosis COPD (emphysema & chronic bronchitis spectrum) *Pleural effusion (uni/bilateral). *Pneumothorax (standard and tension). Lung edge and black lateral to edge (no lung vessel markings). Mediastinal shift in tension seen as tracheal deviation. Seen best with expiratory erect CXR). Lobar collapse Allergic Alveolitis (fibrosing lung) Pneumoconiosis (asbestosis and coal miner’s) Malignant mesothelioma and pleural plaques *Sarcoidosis Pulmonary embolus (Invasive pulmonary angiography remains the gold standard. Computed Tomography Pulmonary Angiography (CTPA) is now performed in most centres. Ventilation-perfusion radionucleotide imaging scan plays a limited role in contemporary practise.) !!Silhouette Sign: loss of silhouette formed by lung adjacent to denser structures such as the heart. Cardiovascular *Heart Failure Pulmonary hypertension HOCM ASD Coarctation of aorta (notching of the ribs due to development of collateral circulation. Seen in older patients) Pericardial effusion (globular appearance) Ventricular aneurysm Valvular disease Gastrointestinal Hiatus hernia (retrocardiac air-fluid level. Paraoesophageal(rolling) hernia) *Pneumoperitoneum (can be small and subtle and takes on a crescenteric appearance. Remember Chaliditi’s sign) *Small & large bowel obstruction (see distinguishing box below)

Feature Small Bowel Obstruction Large Bowel Obstruction Bowel Diameter >3cm < 5cm >5cm Position of Loops Central Periphery Number of Loops Many* Few Fluid Levels Many, short Few, Long (on erect film) Bowel Markings Valvaulae (all the way across) Haustra (partially across) Large Bowel Gas No Yes Paralytic ileus & pseudo-obstruction (no cut off point) Sigmoid & Caecal Volvulus (coffee bean and empty caecum signs respectively. Sigmoid gives bird of prey sign on barium) Subphrenic abcess (usually under the right hemidiaphragm. Air/fluid level may be apparent) Oesophageal candidiasis Oesophageal web Oesophageal varices *Oesophageal carcinoma (raggy stricture, shouldering of stricture) Oesophageal benign (corrosive) stricture (smooth stricture) Achalasia (CXR: widened mediastium, barium swallow: widened oesophagus) Pharngeal Pouch Gastric CA *Crohn’s & ulcerative colitis *Diverticular disease (outpouching of bowel that are lined with barium, v obvious. Think is there other pathology present) *Colorectal cancer (the apple core lesion of an annular CA. Left side > right side of bowel) Colonic polyps (don’t confuse with a residual faecolith in the bowel from poor preparation) Hepatobiliary *Gallstone disease (USS first line. Stone apparent and gives off an acoustic shadow. ERCP, PTC and MRC also used) Hepatic metastases (seen well on USS and CT) *Pancreatitis (acute & chronic), (sentinel loop. Speckled calcification due to deposition in intra-pancreatic ducts. Contrast enhanced Ct scan needed to see necrosis). Urogenital Tract Hydronephrosis Renal calculi (80% seen on AXR. Contrast this with 10-20% gallstones. Beware of phlebolith) Bladder CA Musculoskeletal *Osteoarthritis (Hip, Knee). Unilateral & bilateral. Before & After surgery. (Big 4 signs on XR) Osteoporosis (osteopenia, with vertebral crush #’s). (Crush # seen best on lateral spine. Increased thoracic kyphosis) st*Ankylosing Spondylitis (sacroiliac joint fusion 1. Bamboo spine. Syndesmophyte formations and calcification of longitudinal ligaments, squaring of the vertebrae) Paget’s disease (Often incidental finding on pelvis/AXR – that would impress! Classically tibia bowing and skull bossing too, Seen as increases bone deposition with coarsening of trabecular pattern that appears fuzzy). *Bone metastases (lytic, sclerotic, expansile). (sclerotic lighter than bone. Lytic darker than bone (radiolucent). Rheumatoid arthritis (hands chiefly) Multiple Myeloma (pepperpot skull, pathological #’s) *Femoral neck # (intracapsular v extracapsular. Gardner’s classification of 5 types of femoral neck #) Dynamic hip screw, hemi-arthroplasty and total arthroplasty of hip Breast *Breast CA (big 3; micro-calcification, spiculation and distortion of normal breast contour) Breast cyst Fibroadenoma *Breast shadows, mastectomy & prostheses (uni/bilateral) Nipple markers

!! Imaging one part of the essential triple assessment of a women with a breast lump (USS/mammography, FNCA/biopsy, clinical examination). Neurology Brain neoplasm (macro and micro) Cerebral abcess Cerebral atrophy Cerebral infarct Multiple sclerosis (demyelinating) Assessment of an AXR Technical: Date, Age, Name and Sex of Patient Type of AXR (supine, erect, decubitus) Intraluminal Gas: Size (<3cm small bowel, <5cm large bowel) Distribution of bowel loops (periphery - large bowel, central small bowel) Bowel Markings (large haustra, small valvulae connivente) Ground glass/mottling faecal shadowing. Extraluminal Gas: under the diaphragm Biliary tree Bowel wall Calcification: any structures contain it? Soft Tissues & Bones: Psoas shadows Kidneys (T12-L2) Spleen and Liver Fractures Paget’s Metastatses (sclerotic or lytic) Arthritis Iatrogenic/Accidental & Incidental Any man-made structures indicative of previous operations or other (stents, clips, IUCD, IVC filter). Review Points Technical Specifics of the Radiograph Amount and distribution of gas Extra-luminal gas (evidence of) Evidence of calcification Soft tissue outlines and Bony structures Iatrogenic, accidental and incidental objects Radiology for Finals Assessment of CXR Patient Details: Name, Age, Sex Film Details: Date Taken, Projection (PA, AP, L/R Lateral), single film or one of a series. Technical Details: RIP, Rotation, Inspiration, Penetration. Heart: Size, Border (start at aortic knuckle and work round to SVC) Trachea (pull just off box to see best) Lungs: hilia (size, level) Fields (including apices and behind the heart). Only vessels, end on respiratory tree and horizontal fissure to see) Diaphragm + costophrenic & costocardiac angles Mediastinum (size and shape) Bones (humerus, clavicle, scapula, ribs) The information below is to correspond with the major cases identified in the pastest passing surgical and medical finals books. A central tenant of imaging is that two views 90 degrees to one another are taken in order to localise structures/lesions (orthogonal views). For example, the PA and lateral chest films with a lung mass.

One is able to distinguish a left and right lateral chest radiograph on observation. On the right lateral film the diaphragm can be seen to course from back to front without disruption. However, the left lateral film is disrupted by the intervening cardiac tissue, so not giving a continuous shadow. Surgical Goitre USS may show diffuse enlargement of the thyroid gland and pressure on adjacent structures such as the trachea. Good at distinguishing solid from cystic structures. Radio-isotope scan identifies ‘hot’ and ‘cold’ spots representing nodules that either secrete (hot) or do not (cold). CT can help further delineate nodules and impingement, however the only way to definitely tell if the thyroid is malignant or not is a FNAC. Parotid Gland Swelling Seen very well on axial CT and MRI. Cervical Rib CXR (unlikely to get this) Breast Carcinoma Standard CXR: loss of breast shadow (mastectomy o rarely absent breast). Also identify prosthesis as round, well delineated soft tissue shadow. Nipples can appear as small round densities which must be distinguished from other lung mass (esp, bronchial CA). repeat film with nipple markers if in doubt and compare. Remember that a malignant pleural effusion is a relatively common complication so look for it if notice breast shadow absent. All women 50-64 (soon to be 69) invited to attend 3 yearly mammography. Views taken (mediolateral and craniocaudal views). Mammography a special technique using x-rays. Under 40-45 year olds mammography of little value as glandular breast tissue: adipose ratio higher and difficult to detect masses. These women need an USS. CA Features: Microcalcification Spiculation (spider like) Loss of regular border of breast ** calcification does not always mean cancer. Fibroadenoma Smooth, usually single round density that may calcify. Hepatomegaly/Splenomegaly AXR: diffuse soft tissue (grey) shadow extended below costal margin. USS: good images. Large Kidney AXR: normal kidney 3-3 and half vertebrae in length in T12-L2 region. May see much bigger soft tissue shadow. Can cause displacement of adjacent structures. USS/CT: very clear images. Look for cystic change responsible for large kidneys. Abdominal Masses/Ascites Seen well on USS and CT, but unlikely to ask to look at these. Ascites gives the appearance of a ‘grey haze’ on AXR as fluid in the peritoneal cavity. Inguinal/Femoral Hernia AXR: These can be seen (esp. if large) as bowel loops (maybe distended) within the LIF or RIF.

Femoral Aneursym Arteriography is the gold standard for this and other arterial aneurysms but this does not mean it is what is used in practice. USS may demonstrate aneurysms well as can MR angiography. Testicles Everything to do with testicles is invariably seen on USS as they are superficial, covered in thin skin and soft tissue only. Varicocele seen as a ‘bunch of grapes’. !! if asked what to do if detect left sided varicocele, ‘ I would request a imaging of the kidneys for potential renal malignancy’. Renal mass can press on left testicular vein (asymmetrical anatomy). AAA AXR: May be seen incidentally as calcification indicates internal diameter of vessel. USS first line: abdominal aorta should be 1.5-2.0 cm depending on the location. Greater than 3cm is abnormal. 3-4.5cm needs annual USS observation (surveillance), 4.5-5.5cm needs it 6 monthly. Greater than 5.5cm requires elective repair in most circumstances. Complicated or incidentally found on CT where a thrombus may be seen within the aneurysm. Hip OA XR: loss of joint space, subchondral sclerosis, subchondral bone cysts (black appearance as air/fluid content) and osteophyte formation at the joint margins. Knee XR: As above. Medial compartment loss of joint space >> genu valgus clinically. RA XR: loss of joint space. Periarticular erosions, periarticular osteoporosis. Soft tissue swelling. RA patients get systemic osteoporosis too. ** osteoporosis cannot be seen on XR. If there is bone loss it needs to be > 15% before detectable in which case it is osteopenia. Medical MI CXR: usually very little. May indicate potential cause for MI. ECHO and Cardiac Catheterisation may be undertaken. ECHO:structural integrity, valve function and ejection fraction. CC: vessel patency with view to CABG/PIC. IE ECHO: Valve vegetation and destruction Bronchial CA CXR: coin lesion, area of consolidation (especially if fails to resolve), Lobe collapse (intrabronchial lesion), Pancoast’s apical mass +/- rib destruction. ** standard protocol to have CT of thorax and of liver and adrenals (for metastatic disease) !!CXR shown in a patient that clinically has a Horner’s Syndrome – look at the apices for a Pancoast’s bronchial CA. COPD: Bronchovascular markings may be more evident. Overexpansion with flattened diaphragms. CXR: depends to some extent on which end of the spectrum of chronic bronchitis-emphysema present. 50% will have no CXR findings. Hyperexpansion of lungs (more than 10 posterior or 6 anterior ribs, flattened diaphragm). Emphysema may be seen as bullae. If asked what further imaging one would like: high resolution CT scan identifies the bullae vividly.

Chronic Liver Disease USS: shrunken liver +/- splenomegaly from portosystemic hypertension. Doppler’s allow assessment of flow direction in vein and artery. If following same direction = portosystemic hypertension. IBD UC AXR: Acute toxic megacolon: dilated large bowel loops, characteristically the transverse colon BE: drain pipe/lead pipe colon (no haustral markings). Crohn’s Small Bowel Series: 4 big signs. String sign (of Kantor), Rose thorn ulceration (barium sitting in deep fissures), Bowel loop separation (inflammed bowel irritates nearby loops which move away), Cobblestone mucosa. Multiple Myeloma Pepperpot Skull, Multiple Pelvic deposits. Radioisotope bone scan reveals multiple increases uptake areas. Stroke CT: to distinguish haemorrhage (20%) from infarct (80%). Infarct may not be revealed for several days. Carotid angiography, USS dopplers and MR angiography may all be used in trying to identify a carotid stenosis. If clinically a murmur, do ECHO for potential emboli source in heart. CCF (5 big radiological signs. * perfect question) Upper lobe venous diversion Perihilar oedema (‘bat’s wings) Bilateral pleural effusions Cardiomegaly Kerley B lines (horizontal lines at the level of the cardiophrenic angles) Pleural Effusion Small v Large & Unilateral v Bilateral Meniscus at the lateral aspect. Large PE’s will give the impression of a complete white out of the lung (diff. Diagnosis = pneumonectomy). You may see the chest drain in situ. If the line is straight there is fluid and air (ie, traumatic pneumothorax or iatrogenic on draining effusion). A small PE will need an USS to confirm it. Fibrosing Alveolitis Cannot specifically diagnosis FA. It is the same as other fibrosing lung disease; fine reticulonodular shadowing (dots and lines). TB CXR: Favours the apices of the lungs, hence the review area of the apices on inspecting a CXR. TB lesions may cavitate having a central ‘black’ area with a fibrosed ‘white’ exterior. Look at age and name of patient given its increased prevalence in the old and foreigner. Spots Acromegaly: large spade-like hands on XR. Cardiomegaly on CXR. Marfans: Long, slender hands with spinderly fingers (arachnodactylyl). Pepperpot Skull: Multiple Myeloma (pathological #’s too) (Note: ‘Pepperpot skull’ is a description given to multiple lucencies on the skull x-ray and can occur in other conditions such as hyperparathyroidism.)

Pituitary Tumour: widened sella turcica on lateral skull. Scleroderma: calcinosis seen on hand XR at the pulps. Ank. Spondylitis: bamboo spine (due to squaring of the vertebrae), calcification of the longitudinal ligaments. Sacroileitis over the ileopectoneal lines (*first sign). Paget’s Disease Plain XR’s: pelvis, tibia and skull favoured locations. Disorder of bone resorption/deposition. ‘Fuzzy’ areas of XS bone. Radio-isotope scan shows areas of high bone turnover which takes up the isotope. Osteoporosis: DEXA (dual energy x-ray absorptiometry). Get T and Z Readings. T is overall bone density. Z compares it to age and sex matched controls. th April 2006) ICB 23/01/02 (Updated: 7

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