X-Ray Quiz: Practise Reading Real X-Rays

Answer: Fifth metacarpal neck fracture (boxer’s fracture). The neck of the fifth (little-finger) metacarpal is broken just behind the knuckle, and the metacarpal head is tipped towards the palm. Tip: Punch injuries hit the fourth and fifth metacarpals, so start on the little-finger side. Image source: Boxerfraktur by Hellerhoff.

Answer: Left pneumothorax. The left side is darker, with no lung markings beyond a thin white line: the edge of the collapsed lung (the visceral pleural line). Tip: Trace the lung markings out to the chest wall on both sides. Where they stop short, look for a pleural line. Image source: Pneumothorax CXR by Photographed by User Clinical Cases 00:42, 7 November 2006.

Answer: Colles fracture. The distal radius is broken just above the wrist, and on the side view the broken end is tilted backwards (dorsally). That gives the ‘dinner fork’ look. Tip: Always look at the lateral view: tilted back is Colles, tilted towards the palm is Smith. Image source: Colles' Fracture of Radius by Lucien Monfils.

Answer: Left pleural effusion. A dense white opacity fills the left lower chest, hides the left hemidiaphragm and has a curved upper edge rising towards the side wall (the meniscus sign). Tip: Fluid lies at the bottom on an upright film, so the first sign is a blunted costophrenic angle. Image source: Pleural effusion of primary pulmonary tuberculosis by Basem Abbas Al Ubaidi.

Answer: Anterior shoulder dislocation. The humeral head sits below and in front of the glenoid (the socket) instead of inside it. Tip: Anterior dislocations are by far the most common. Check the numbness over the deltoid (axillary nerve) before and after reduction. Image source: Shoulder dislocation by Drfrancescsoler.

Answer: Fractured neck of the right femur. On the patient’s right (the left of the image) the femoral neck is broken and the shaft has ridden upwards, so the smooth curve of Shenton’s line is broken. The left hip is intact. Tip: Trace Shenton’s line along the femoral neck and the top of the obturator foramen on both sides. If the film looks normal but she still can’t bear weight, ask for CT or MRI. Image source: Neck of Femur fracture Right side in a 80 years old female patient by Drvaram.

Answer: Osteoarthritis. The joint space is narrowed more on one side (arrow) than the other, with bony spurs (osteophytes) at the joint margins and denser bone beneath the cartilage. Tip: Remember LOSS: Loss of joint space, Osteophytes, Subchondral sclerosis, Subchondral cysts. Uneven narrowing suggests osteoarthritis; even narrowing with eroded, thin bone suggests rheumatoid. Image source: Osteoarthritis left knee by James Heilman, MD.

Answer: Supracondylar fracture of the humerus. There is a break across the lower humerus just above the elbow joint, with the lower fragment shifted. This is the most common elbow fracture in children. Tip: On a child’s lateral elbow film, look for a lifted fat pad and check that the anterior humeral line still passes through the capitellum. Image source: Supracondylarfrac by James Heilman, MD.

Answer: Small bowel obstruction. Many dilated, centrally placed loops of bowel show stacked air–fluid levels. Adhesions from past surgery are the most common cause. Tip: The 3-6-9 rule: small bowel over 3 cm, colon over 6 cm and caecum over 9 cm is too wide. Image source: Upright X-ray demonstrating small bowel obstruction by James Heilman, MD (cropped).

Answer: Enlarged heart shadow. The heart shadow is wide, taking up well over half the width of the chest, and the lung vessels look congested. Here fluid overload from post-streptococcal glomerulonephritis is the cause. Tip: Measure the cardiothoracic ratio on a PA film: heart width over chest width above 0.5 is enlarged. AP films and a big thymus in small children make the heart look bigger. Image source: Source page by CDC/Dr Thomas Hooten.

Answer: Upper oesophagus, at the level of the thoracic inlet. The narrowest point of a child’s oesophagus is at the top, at the cricopharyngeus near the thoracic inlet, and that is where most swallowed coins lodge. A flat object in the oesophagus is usually seen face-on on a frontal film. Tip: A child who swallowed a button battery needs an X-ray straight away: it can burn through the oesophagus within hours. Image source: X-ray of Trinket Swallowed by a Child (FDA010) (6946959167) by The U.S. Food and Drug Administration (cropped).

Answer: Free gas under the diaphragm (pneumoperitoneum). A thin dark crescent of gas separates the right hemidiaphragm (green arrows) from the top of the liver (red arrows). The blue arrows show normal gas inside the bowel on the left. Here a perforated peptic ulcer is the likely cause. Tip: Free gas rises, so the patient needs to sit upright for 10 minutes or so first. A crescent with no bowel folds in it is free gas; folds crossing it suggest Chilaiditi. Image source: Pneumoperitoneum by Hellerhoff.

Answer: Sigmoid volvulus. One enormous, inverted-U loop of large bowel rises out of the pelvis towards the upper abdomen: the ‘coffee bean’ sign of a twisted sigmoid colon. Tip: Sigmoid volvulus points from the pelvis up towards the right upper quadrant; caecal volvulus starts on the right and usually points up to the left. Image source: Sigmoidvolvulus by Mont4nha.

Answer: Miliary tuberculosis. Countless tiny nodules, each only 1 to 3 mm, are spread evenly through both lungs, like millet seeds. That pattern means spread through the bloodstream. Tip: Tiny, even, everywhere: think miliary TB in anyone immunosuppressed, and look closely, because early films can look almost normal. Image source: Chest radiograph of miliary tuberculosis 1 by Benjamín Herreros, Isabel Plaza, Rebeca García, Marta Chichón, Carmen Guerrero and Emilio Pintor.

Answer: Scaphoid fracture. A faint lucent (dark) line crosses the waist of the scaphoid. These fractures are easy to miss and can be invisible on the first film. Tip: Snuffbox tenderness with a normal X-ray still needs a splint and follow-up imaging: the scaphoid’s blood supply enters from the far end, so missed fractures risk avascular necrosis. Image source: Scaphoid fracture - barely visible on initial X-ray by Mohamed Jarraya, Daichi Hayashi, Frank W. Roemer, Michel D. Crema, Luis Diaz, Jane Conlin, Monica D. Marra, Nabil Jomaah, and Ali Guermazi.

Answer: Toxic megacolon. The colon is markedly dilated, with the transverse colon well over 6 cm and the normal haustral folds lost, in someone who is systemically unwell with colitis. Tip: It’s a clinical plus X-ray diagnosis: a dilated colon alone isn’t enough without fever, tachycardia or other signs of toxicity. Image source: Toxic Megacolon in Ulcerative Colitis by Hellerhoff.

Answer: Ankylosing spondylitis. Thin, smooth bony bridges (syndesmophytes) join the vertebrae into one continuous column, the ‘bamboo spine’ of late ankylosing spondylitis. Tip: Look at the sacroiliac joints first: sacroiliitis comes early, the bamboo spine late. DISH has chunky, flowing bone on the right side of the spine and spares the SI joints. Image source: Bamboo spine ankylosing spondylitis by Stevenfruitsmaak.

Answer: Cavitating pulmonary tuberculosis. Patchy shadowing in both upper zones with a thick-walled cavity at the right apex. Reactivated TB favours the apical and posterior segments of the upper lobes. Tip: Upper-zone shadowing plus a cavity in someone with weight loss and night sweats is TB until proven otherwise: isolate and send sputum. Image source: Source page by CDC.