TIPS AND PITFALLS IN PLAIN FILM INTERPRETATION Dr Philip Touska MBBS, BMedSci(Hons), MRCS, DO-HNS, FRCR Radiology Fellow Guy s & St Thomas Hospitals
LEARNING OBJECTIVES Where do we go wrong? Common pitfalls Brief recap of basics Technique, adequacy and anatomy Cases Interactive session
Errare humanum est Seneca WHERE CAN WE GO WRONG? Technical E.g. Rotation, limits of technique Perceptive Missed finding, distraction by obvious abnormalities Interpretative Misdiagnosis
SYSTEMATIC APPROACH AABCDEF Adequacy (technical quality) Airways Breathing (lungs) Circulation (heart and vessels & hila) Densities (bones/prostheses/surgical clips) Edges (incl. skin/breasts) Fundus of stomach (gastric bubble/under the diaphragm)
PA radiograph = outpatients and some inpatients AP radiograph = most inpatients Magnification ~22% Sources: Fundamentals of radiography. (1) https://clinicalgate.com/radiologic-examination-of-the-chest. (2) Young-Cheol J et al. IJST 2015.
Leftward rotation = slightly enlarged cardiac silhouette
CHEST RADIOGRAPH
Airway Bronchi
Lungs and fissure
Left subclavian a. SVC Azygous vein Pulmonary veins Pulmonary arteries Thoracic aorta RA, LAA, LV
Scapula Ribs Vertebrae Gastric bubble
SYSTEMATIC APPROACH ABDO X Air (in right place) Bowel (wall thickness) Dense structures (bones/calcification) Organs external object/artefacts
Gastric bubble Caecum Ascending colon Transverse colon Descending colon Sigmoid colon & rectum Liver L kidney R psoas muscle
INTERACTIVE CASES Fingers on buzzers please
43 year old SOB
WHAT IS THE DIAGNOSIS? 1. Left upper lobe collapse 2. Upper mediastinal mass 3. Aortic rupture 4. Lymphadenopathy
37 year old chest pain & pyrexia
WHAT IS THE MAIN DIAGNOSIS? 1. Right lower lobe consolidation 2. Middle lobe consolidation 3. Primary lung malignancy
51 year old SOB and cough
WHERE IS THE MAIN ABNORMALITY? 1. Right upper zone 2. Left upper zone 3. Right middle zone 4. Left middle zone 5. Right lower zone 6. Left lower zone
48 year old chest pain
WHERE IS THE MAIN ABNORMALITY? 1. Right upper zone 2. Left upper zone 3. Right middle zone 4. Left middle zone 5. Right lower zone 6. Left lower zone
65 year old SOB and cough
WHAT IS THE DIAGNOSIS? 1. Normal study 2. Tuberculosis 3. Primary lung cancer 4. Upper lobe collapse
53 year old SOB and cough
WHAT IS THE NATURE OF THE ABNORMALITY? 1. Pulmonary arterial hypertension 2. Lymphadenopathy 3. Primary lung cancer
38 year old acute chest pain
WHAT IS THE DIAGNOSIS? 1. Normal study 2. Pneumomediastinum/pneumopericardium
78 year old confused NG tube check
WHERE IS THE ABNORMALITY? 1. Airway 2. Lung parenchyma 3. Hila 4. Below the diaphragm
82 year old cough and SOB
WHAT IS THE DIAGNOSIS? 1. Left upper lobe collapse 2. Left lower lobe pneumonia 3. Left lower lobe collapse
56 year old - chest pain
HOW MANY ABNORMALITIES? 1. One 2. Two 3. Three
34 year old acute chest pain & cough
WHAT IS THE DIAGNOSIS? 1. Pneumonia 2. Acute cardiac failure 3. Sickle crisis 4. Hyperparathyroidism
47 year old SOB
WHAT IS THE DIAGNOSIS? 1. Acute pulmonary oedema 2. Incidental lung cancer 3. Combination of above
21 year old chest pain and SOB
WHAT IS THE DIAGNOSIS? 1. Lymphoma 2. Pneumonia 3. Tuberculosis
60 year old chest pain
WHERE IS THE ABNORMALITY? 1. Airway 2. Lungs 3. Mediastinum 4. Bones
19 year old chest pain and SOB
WHERE IS THE ABNORMALITY? 1. Right upper zone 2. Left upper zone 3. Right middle zone 4. Left middle zone
84 year old abdominal pain
IS THERE AN ACUTE ABNORMALITY ON THIS FILM? 1. Yes 2. No
WHAT IS THE DIAGNOSIS? 1. Small bowel obstruction 2. Sigmoid volvulus 3. Caecal volvulus 4. Perforation
45 year old abdominal pain & PR bleeding
WHAT IS THE DIAGNOSIS? 1. Infective colitis 2. Ischaemia 3. Inflammatory bowel disease 4. Any of the above
56 year old abdominal pain
57 year old abdominal pain
SUMMARY AVOIDING PITFALLS Poor/limited technique Rotation, limited inspiration, AP projection, limitations of the technique Perceptive errors Missed finding, distraction by obvious abnormalities Interpretative errors Misdiagnosis Solution: Know the limitations of the study/technique consider other e.g. CT tekn Solution: Use a systematic approach; avoid satisfaction of search Solution: Consider alternatives, phone a friend!
THANK YOU EMAIL: P.TOUSKA@DOCTORS.ORG.UK @PTOUSKA
SILHOUETTES
WHAT TO LOOK FOR? 1. Bowel Is it small bowel or large bowel? Is it dilated? 3, 6, 9 cm rule Does it look normal? 2. Is there air where it shouldn t be? - Perforation 3. Densities (stones/surgical clips/foreign bodies) 4. Anything else? Bones/soft tissues/organs/masses
SMALL BOWEL Characteristics Often invisible under normal circumstances Position: central Size: small (max 3cm diameter) Valvulae conniventes (uninterupted lines)
LARGE BOWEL Characteristics Usually visible under normal circumstances faecal shadowing Position: peripheral (note: sigmoid & transverse colons are floppy may be central) Size: large (max diameters: 6cm transverse colon, 9cm caecum) Haustra (interrupted lines)
39 year old SOB and cough