` Chest radiography interpretation Ń Approach, pathology ` Foot/Ankle Ń What to order, what to find ` To contrast or not to contrast Matthew Tommack, D.O. October 5,2017 Approach Consolidation Atelectasis Pulmonary Edema Pleural Effusion Pneumothorax ` Technique, type and quality ` Ribs and spine ` The margins of the ` Upper abdomen diaphragm and ` Soft tissues mediastinum ` Borders of the Ń Air-contrast from the mediastinum/heart adjacent lung. ` Lungs ` Lung consolidation Ń Pneumothorax (fluid filled) (i.e. Ń Consolidation pneumonia) Ń Pleural effusion Ń Contrast is lost and the Ń Interstitium/vessels contour disappears. ` When alveolar infiltrate develops, air is replaced ` When fluid accumulates in lung by fluid Ń Alveolar (airspace) compartment ` Fluid does not create contrast with vessels and Ń Interstitial compartment boundaries to the lung ` In addition to increasing the lung density, Ń Boundary obscuration the infiltrate cancels the contrast between ` The particular structure that is obscured vessels and lung boundaries, and these indicates which portion of lung is involved structures disappear, ie silhouette sign ` The disappearance of a normal lung border (ie. ` Air filled bronchi, normally invisible, will be mediastinum or diaphragm) is called the contrasted by consolidation creating air silhouette sign bronchograms ` The unit of alveolar consolidation is served by a single terminal bronchiole Ń Represents a fluffy 3-5 mm nodule ` In most alveolar consolidations, these fluffy alveolar nodules coalesce Ń Pores of Kohn ` Communication between alveolar spaces mean that disease tends to spread freely until the pleura is reached. Ń Typical "lobar" distribution of pneumonia ` RUL: right superior mediastinum (SVC) ` RML: right heart border ` RLL: right hemidiaphragm or right heart border if medial RLL ` LUL: left superior mediastinum (aortic arch) ` Lingula: left heart border ` LLL: left hemidiaphragm or descending aorta ` Obstructive / Resorptive Ń Endobronchial Lesion ` Lobar ` Passive / Relaxation ` Ń Pleural Effusion, Pneumothorax Segmental ` ` Compressive Subsegmental Ń Bulla (Plate/Streak) ` ` Cicatricial/Scarring Round Ń Radiation Fibrosis ` Adhesive Ń Neonatal Respiratory Distress Syndrome/Hyaline Membrane Dz Pneumoperitoneum ` Heart size on ideal PA film Ń Heart width should be less than 50% of chest cavity width. Ń Cardiac enlargement is common in CHF ` Normal upright upper lung pulmonary vessels 1/3 the size of basilar vessels. ` Early CHF Ń Basilar edema causes shunt to upper lobe = cephalization of flow. ` Interstitial edema Ń Thin Kerley B lines (septal lines) and thick bronchi ` Parahilar alveolar edema Ń Usually symmetric and non-segmental ` Measurement of the Cardiothoracic ratio: [(MRD+MLD)/ID] ` A value of <0.5 is normal (<0.6 in infants). ` Enlargement may come from heart or pericardium. ` Pleural effusion is seen in many conditions Ń Heart failure Ń Tumor Ń Pneumonia Ń Trauma ` Obscures and compresses underlying lung ` Effusions are readily detected Ń Can point to underlying problem that may not be seen on x-ray, ie infection, tumor ` On routine upright chest x ray, need 200-300 mL of pleural fluid to blunt costophrenic angle ` On lateral view, need only 75cc to blunt posterior costophrenic sulcus ` Lateral decubitus is most sensitive and can be helpful to determine of fluid is loculated ` Injury to the lung, either trauma or iatrogenic ` Air leakage into the pleural space ` Spontaneous cases (idiopathic) also occur ` Severity and duration of pneumothorax is made worse by increased airway pressure Ń Obstructive airway disease or positive pressure ventilation ` If a "flap valve" mechanism is present, progressive enlargement of space may compromise cardiac filling and ventilation (tension pneumothorax) ` Expiratory films aid in detection ` Skin folds often simulate pleural lines Ń True pleural line has air on both sides of a fine line Ń Most pneumothorax look-alikes have air on only one side and are not real lines ` Mastectomy ` Bulla/blebs ` Discussed normal chest x ray with development of approach ` Common clinical pathologies ` Questions ` Anteroposterior ` AP Mortise (15-20 degrees oblique- to correct for normal external rotation) ` Lateral View ` Varus and Valgus Stress Views ` Hindfoot view ` Anteroposterior (+/- WB) ` Calcaneus Axial and Lateral ` Medial Oblique ` Sesamoid View ` Lateral View (+/- WB) ` Toes AP, Oblique and Lateral ` Lateral Oblique ` Lateral malleolus ` Medial Malleolus ` Tibial Plafond ` Medial Malleolus ` Talus ` Lateral malleolus ` ` Calcaneus Talus ` Lateral clear space 4 mm ` Ankle joint 3-4mm width ` Tibiofibular overlap - 1mm ` Tibiofibular overlap – 6-10 mm ` All portions of joint should be 3-4mm ` Syndesmotic clear space 4-6mm Ń 1cm above tibial plafond Ń Lateral border of posterior tibial margin to medial fibula ` Medial clear space—4 mm, 0.5cm below plafond ` Tibia Posterior Malleolus ` Sustentaculum tali ` Talus (head, neck, body, lateral process) ` Medial facet of ` Tibiotalar and subtalar joints calcaneus ` Posterior facet ` Navicular calcaneus ` Calcaneus (anterior process, tuberosity) ` Calcaneus ` Base of 5th ` 5th Metatarsal ` Kager’s Fat and Achilles ` Bohlers angle-20-40 normal, less than 20 abnormal ` Angle of Gissane- >130 abnormal ` Talus and Calcaneus ` Talus and Calcaneus ` Navicular and Cuboid ` Navicular and Cuboid ` Cuneiforms (medial, ` Coalition*** middle, lateral) ` Cuneiforms ` 1st-5th Metatarsals ` Metatarsal ` Phalanges ` Tarsometatarsal joints ` Lisfranc interval Ń Joint space and ` Iimitations 2-5th TMT alignment ` Hallux Valgus- >15 degrees ` Tibia and Fibula ` Varus/ valgus ` Talus (head, neck, body) ` Talar congruence ` Tibiotalar and subtalar joints ` Talocalcaneal and subfibular ` Navicular impingement ` Calcaneus (anterior process, tuberosity) ` Base of 5th Metatarsal ` Tarsometatarsal axis/tarsal base angle-14-36 degrees ` Calcaneal pitch-20-30 degrees • Weber A (infrasyndesmotic transverse fibula fx)— Supination Adduction • Weber B (fibula fracture at or near the plafond)— Supination-Ext Rotation (spiral fx on lateral) or Pronator-Abduction (short oblique fx on AP) • Weber C (high fibular fracture)— Pronator External Rotation • Isolated medial malleolus fracture or deltoid ligament injury • Isolated posterior malleolus fracture • Image entire Fibula • Physes are the weak point in children- ligaments are stronger • Salter Harris 3 fracture of anterolateral epiphysis/physis- medial fused • Triplane fracture= Juvenile tillaux + an oblique/coronal posterior metaphyseal fracture (SH 4) Involvement of anterior lip of tibial plafond and disruption of the articular surface ` Neck most frequent site, neck and body 2nd, body rd • Most common only 3 posteromedial or ` Grading depends on displacement, involvement of anterolateral posterior subtalar joint, and amount of additional joints involved Medial OCD-deep ` • Osteochondral Injuries common of Talar dome round lesion due ` Neck and body at increased risk of AVN of Talar Body to impaction Ń Hawkins sign 6-8 weeks post, reliable sign that AVN will NOT develop as bone is vascularized • Lateral OCD- ` Look for Shallow flake of Ń Impaction of articular surface avulsed Ń Encarcerated fragment Ń Relationship of fractures and fracture fragments to tendons cartilage/bone ` Uncommon ` Oblique views may be ` Usually forced necessary inversion ` Sx depends ` Associated with displacement and on how much articular extensor dig brevis surface of tendon avulsion calcaneocuboid ` Tension of bifurcate articular surface is ligament involved Ń Attaches anterior process ` Nonunion most to cuboid and navicular common complication Daftary, et al. Fractures of Calcaneus: A review with Emphasis on CT, Radiographics, 25,5, 2005. Medial Dorsal Superficial Capsule Extensor Retinaculum Digitorum Brevis • Partial vs complete • Homolateral: MTs dislocated to the same side, usually 2nd through 5th MTs dislocated laterally • Divergent: Medial displacement of 1st MT and lateral displacement of 2-5 Risk for nonunion due Mts to poor vascularity compared to tuberosity fractures ` Can the pt receive contrast ` Ń Allergies Prior reaction to iodinated contrast Ń Renal function ` Prior severe allergy to anything Ń Medical history ` Kidney function, eGFR Ń Medications Ń Preexisting renal insufficiency ` Does the pt need contrast Ń Over 60 Ń Can we answer the question without contrast Ń Diabetes Ń If we are going to give contrast, how can we optimize it’s Ń metformin use Ń Kidney disease ` Different ways to use contrast Ń HTN Ń Venous phase Ń CVD Ń Arterial phase Ń Solitary kidney Ń Delayed Ń Transplant Ń Intrarticular Ń Other factors contributing to nephrotoxicity Ń Ouline lumen x Chemotherapeutic drugs x myeloma ` Biggest worry is nephrogenic systemic sclerosis, ` Contrast ` No contrast NSF, fibrosing disease of skin and subcutaneous Ń Vessels/vessel injury Ń Air Ń Visceral enhancement x Pneumothorax tissues Ń x Ń Bowel Wall enhancment Pneumoperitoneum Identified in 2006 with association to GBCA’s Ń Identifying structures Ń Calcification Ń eGFR used to screen adjacent to vessels or x renal stones ` bowel x Sometimes gallstones Brain deposition-appears to be dose dependent Ń Ń Safety alert announced in 2015, however no adverse Enhancement pattern Ń CT lung cancer screening or x Masses lung nodule follow up health effects have been discovered x Ń Ń Rigorous investigation on going Liver, kidneys Bones x Excretory system x Fractures, alignment ` Well tolerated as IV contrast x Ureters, bladder Ń Head trauma/stroke Ń Much lower