tubes such as ET tubes and chest drains, but for an accurate assessment of injuries CT is r equired. Has a high negative predictive value for aortic injury if normal but have high level of suspicion if aortic arch not clearly seen. CT (Fig. \200 CT of the chest should be part of radiological assessment in all cases of 20.4 ) severe polytrauma. Gives accurate assessment of lung, mediastinal, bony, and diaphragmatic injuries. A normal, good quality CT has an almost 100 % negative predictive value for aortic injury. Ultrasound Can be used to look for haemothorax or pneumothorax in experienced hands, but is not as accurate as CT. MRI Little role in acute setting, but can be useful in delayed diagnosis of diaphragm ruptu re. Angiography Largely replaced by multislice CT as a diagnostic tool, but developing an ever- increasing role in the treatment of acute vascular injury, including aortic transection. SUBASH KC/NMC-15TH/2014 THORACIC TRAUMA 319 (a) (b) Fig. 20.4 a road traf \201 c accident. a) The \201 rst CT is viewed on \200\230mediasti nal \200\231 windows, showing \202 uid within the left chest, and active bleeding, seen a s contrast dependently within the lower left chest. b) The second CT is the same image view ed on \200\230lung \200\231 windows, showing an associated pneumothorax. Axial CT images from a patient who sustained multiple injuries following SUBASH KC/NMC-15TH/2014 320 CHAPTER 20 Trauma Abdominal trauma This remains a major cause of morbidity and mortality in the Western world . Perhaps not surprisingly road traf \201 c accidents (RTAs) remain the major cause even w ith modern safety developments. Traditional ATLS (Advanced Trauma Life Support) management relied upon good clinical history taking, examination and basic bedside tests. The exponential imp rovement in CT technology means that, where available, CT really should be the C in the ABC approach. Clinical presentation The presentation can be variable although high-energy mechanisms shou ld raise concern that for an intra-abdominal injury. Obviously direct trauma to the abdomen or lower rib cage carries a very high risk and there should be a very low threshold for im aging these patients. Imaging Ultrasound FAST (focused assessment with sonography for trauma) scans remain popula r in emergency departments as the demonstration of free \202 uid con \201 rms that there is an intra-abdominal injury. Unfortunately ultrasound remains very poor at delineating th e injuries themselves and is of little value in assessing bowel trauma. Ultrasound does, however, retain a role in following-up known injuries, particularly in children where dose is an issue. CT (Fig. It is now well recognized that anyone with presenting with injuries to 2 or more m ajor body parts should have a Pan-Scan (vertex to symphysis). This is because these patient s often have multiple injuries some of which can be very dif \201 cult to locate surgicall y. 20.5 ) Traditional teaching is that no haemodynamically unstable patient should go for a CT scan. Once again the speed of modern scanners means that patients spend very little time in the s can room. Indeed the rapid and accurate identi \201 cation of life-threatening injuries is unsurpassed by any other approach. Once the scan is done and all the injuries identi \201 ed then a management plan for the p atient for the remainder of his hospital stay can be drawn up. Information for the radiologist \200 Mechanism of injury. \200 Known injuries. \200 H aemodynamic status. SUBASH KC/NMC-15TH/2014 ABDOMINAL TRAUMA 321 Fig. 20.5 showing active bleeding from the spleen (arrow) and intra-abdominal free blood (a rrowheads). Trauma. A 35-year-old female who had fallen off her horse. Axial CT SUBASH KC/NMC-15TH/2014 322 CHAPTER 20 Trauma Pelvic fractures Pelvic fractures are associated with high-energy injuries (in the UK eithe r RTAs or falls from a height). The incidence of pelvic fractures in patients with blunt tr auma is approximately 10 skeletal structure whose integrity is maintained by extremely stro ng ligaments and powerful muscles. % . The pelvis is an extremely resilient Hence, any trauma to the pelvis has a high risk of injury to the soft tissues, abdominal or gans, and spine. The most important association is with active bleeding. Clinical presentation The main mechanisms of injury occur through 3 vectors: \200 AP comp ression: this is the commonest type of injury characterized by pubic diastasis sacroiliac (SI) joint disruption. AP compression can result in an increa se in the volume of the pelvis putting the patient at risk of exsanguination. Lateral compression: the hallmark of lateral compression fractures is the fracture of the p ubic rami with sacral buckle fractures. This is associated with intra-abdominal and intra-p elvic injuries but is less likely to have major pelvic hemorrhage. Vertical shear injuries occur due to a vertical force, often from the femur. There are vert ical fractures of the pubic rami and SI joints with ligamentous disruption and hemi-pelvic displacement. Imaging Plain \201 lm The AP pelvis \201 lm allows the initial assessment of the pelvic bones and their alignment (Fig. 20.6 ). CT \200 CT is the modality of choice for assessment of pelvic injuries, as not only does it give detailed analysis of the fractures but it demonstrates the associated soft tissue i njuries. The most important \201 nding is of active bleeding. MRI MRI can help in identifying occult fractures of the pelvis and hips. Information for the radiologist \200 Mechanism of injury. \200 The haemodynamic status of the patient. SUBASH KC/NMC-15TH/2014 PELVIC FRACTURES 323 A 65-year-old male admitted after frontal impact in an RTA. AP pelvic Fig. 20.6 radiograph which demonstrates disruption to the pubic symphysis and external rotation of the left hemi -pelvis. This is consistent with an AP compression injury (open book). SUBASH KC/NMC-15TH/2014 324 CHAPTER 20 Trauma Shoulder trauma Shoulder trauma presents with a variety of fracture/dislocation patterns. U sually it is the result of a fall onto an awkwardly held arm. Clinical presentation Patients with a fracture can usually get the arm into a semi-comforta ble position compared to a dislocation, which is exceptionally painful no matter what they do. Imaging Plain \201 lm Most shoulder injuries can be diagnosed with conventional radiograp hy. Clavicular fracture These commonly occur at the junction between the middle and outer third s. There may be displacement and fragment overlap. Acromio-clavicular (AC) joint subluxation/dislocation (Fig. Seen as widening and vertical s eparation of the AC joint space. Comparison or weight-bearing views of both shoulders can b e helpful. 20.7 ) Anterior dislocation (commonest) This is characterized by subcoracoid position of the humer al head on the AP view. The dislocation is often more obvious in a scapular \200\230Y \200 \231 view, where the humeral head lies anterior to the \200\230Y. \200\231 In the axillary view, the \200\230golf ball \200\231 (i.e. humeral head) falls anterior to the \200\230t ee \200\231 (i.e. glenoid). Posterior dislocation (2 The AP view may show medial rotation of the humeral head, resembli ng a light bulb. The scapular \200\230Y \200\231 view reveals the humeral head behind the glenoid (the center of the \200\230Y \200\231). In an axillary view, the \200\230golf bal l \200\231 falls poste- riorly off the \200\230tee \200\231. % ) Inferior dislocation (rare) The patient presents with arm held abducted above the head. The AP view may show the arm raised over the head with the humeral head infe- rior to the glen oid. Humeral neck/head fracture These are often impacted or oblique fractures. They are classi \201 ed according to separation of the head, shaft, greater and lesser tuberosities (Neer c lassi \201 cation). CT Indicated for radiographically occult injuries and for surgical planning of complex frac tures. MRI This is the investigation of choice for soft tissue, cartilage, and bone marrow assessm ent. Information for the radiologist Does the mechanism match the injury demonstrated? SUBASH KC/NMC-15TH/2014 SHOULDER TRAUMA 325 Fig. 20.7 A 30-year-old male who fell off his mountain bike and has presented with a grossl y deformed left shoulder joint. The \201 gure shows dislocation of the acromio-clavicular joint. SUBASH KC/NMC-15TH/2014 326 CHAPTER 20 Trauma Elbow trauma The elbow is a hinge joint comprising the radius, ulna, and humerus. These are at risk when falling onto the outstretched arm. Clinical presentation Injuries to the elbow joint can lead to a loss in \202 exion, exten sion, or even a locked joint. Imaging Plain \201 lm This is the mainstay of trauma imaging for the elbow with CT and MR I limited to complex injuries. Elbow joint effusion This is the single most important \201 nding. Fat pads, which lie on the anterior and posterior surfaces of the distal humerus, are not usually visualized. Wit h an elbow joint effusion, they are lifted off the humeral surface and seen on the lateral view as dark gray triangular structures. In trauma, they are associated with fractures even if one is not readily seen (usually an undisplaced radial head or supracondylar fracture). Anterior humeral line and radiocapitellar line The anterior humeral line is drawn along the anterior cortex of the distal humerus and should pass through the middle 1/3 of the capite llum. Malalignment indicates the presence of a fracture (e.g. supracondylar or lateral cond yle fractures). The radiocapitellar line demonstrates the congruence between the radial head and the capite llum. The line should be drawn through the proximal radius and should intersect the center of the capitellum on any view. Malalignment indicates dislocation of the elbow or radial he ad. Elbow fractures There are multiple fracture types with the most common being the radial hea d/neck and supracondylar humeral fractures. In pediatric patients, always look for the medial epicondyle as if avulsed it is pulled into the joint and can be dif \201 cult to identify. Elbow dislocation These are classi \201 ed according to the direction of dislocation and a ssociated fractures. The most frequent injury is posterolateral dislocation. Information for the radiologist Is the joint locked or is there a loss of extension or \202 exion? SUBASH KC/NMC-15TH/2014 ELBOW TRAUMA 327 (a) (b) Fig. 20.8 signi \201 cant displacement of the ulna shaft from the olecranon. Images a) and b) demonstrate a multisegmental fracture of the elbow with SUBASH KC/NMC-15TH/2014 328 CHAPTER 20 Trauma Hand and wrist trauma Clinical presentation Patients with a fracture can usually get the ar m into a semi-comfortable position compared to a dislocation, which is exceptionally painfu l no matter what they do. Imaging Plain \201 lm ( Figs. 20.9 and 20.10 ) This remains the mainstay for imaging for these areas as most injuries are well demonstrated by plain \201 lms. Where the imaging d oesn \200\231t match the clinical \201 ndings then further investigations should be consi dered. Distal radial fractures The classic Colles \200\231 fracture consists of a transverse fract ure of the distal radius (within 2.5cm of the wrist) with dorsal angulation of the distal f rag- ment. It may be associated with avulsion of the ulnar styloid process. The less common Smith \200\231s fracture refers to volar angulation of the distal radial fragment and is very unstable. Scaphoid fracture Specialized scaphoid views should be obtained (AP, lateral, right, and le ft obliques). The scaphoid most commonly fractures transversely through the waist, but some times through the tubercle. Waist fractures are associated with a high incidence of avascul ar necrosis of the proximal pole due to interruption of its blood supply, which is via the distal pole. Scaphoid fractures may not be visible on initial radiographs. Snuffbox tenderness without a radiographically visible fracture should be followed up closely with clinical review. Pers isting symptoms after 10 \200\22314 days require further imaging with either a bone scan or MRI to identify any underlying injury. Lunate dislocation This is a rare but often missed injury. The lunate dislocates anteriorly . This may be dif \201 cult to appreciate on the AP \201 lm, but is more easily seen on the lateral view with the lunate rotated and displaced anteriorly. Perilunate dislocation In perilunate dislocation, the lunate remains attached to the radius with the remainder of the carpal bones displaced posteriorly. There is only minimal, if an y, rotation of the lunate. This injury is often associated with a scaphoid fracture (trans- scaphoidperilunate dislocation), or fracture of the radial styloid. Other carpal fractures Avulsion fracture of the posterior surface of the triquetral may be seen on the lateral view as a small fragment adjacent to the dorsal surface of the bone. It is also possible to fracture any of the other carpal bones, but this tends to be much less common. Ligament and cartilage injuries The wrist contains many important ligaments and cartilages that support the carpal bones and which may be injured following trauma. The most SUBASH KC/NMC-15TH/2014 HAND AND WRIST TRAUMA 329 commonly injured structures include the scapholunate ligament, tri- quetrolunate ligament a nd the triangular \201 brocartilage complex. These injuries are best investigated with st ress views (to demonstrate carpal instability) or MRI. Metacarpals and phalanges These are common fractures. It is important to assess the degree of angu- lation/displacement to guide further management. Thumb Bennet \200\231s fracture-dislocation describes fracture of the base of the \201 rs t metacarpal which extends into the carpometacarpal joint (i.e. it is intra- articular). Th ere is lateral subluxation of the main metacarpal fragment. A Rolando fracture is a comminuted intra-articular fracture through the base of the 1 T- or Y-shaped. st metacarpal consisting of 3 distinct fragments; it is typically Information for the radiologist What is the mechanism of injury and does the imaging match the clinical \201 ndings? (a) (b) Fig. 20.9 This is a 60-year-old lady who fell over on the ice with a painful deformed wrist . a) AP view showing gross deformity with signi \201 cant radial translation. b) The later al con \201 rms signi \201 cant dorsal translation. SUBASH KC/NMC-15TH/2014 330 CHAPTER 20 Trauma (a) (b) Fig. 20.10 radiograph is dif \201 cult to interpret but the middle carpometacarpal joint i s indistinct as is the distal capitate. b) Coronal CT reformat con \201 rms a multi-segmen tal fracture of the capitate involving the middle carpometacarpal joint. A 20-year-old male with a painful hand after punching a wall. a) The AP SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014 332 CHAPTER 20 Trauma Proximal femoral fractures Lower limb fracture patterns can present in a number of ways, de pending on mechanism of injury, age of patient, and underlying bone strength. The femur req uires large forces to fracture or dislocate it, except in cases of osteoporosis, tumor, or infection. Clinical presentation Fractured neck of femur (NOF) This is a common injury in the elderly. Patients present with groin pain or pain radiating to the knee following a fall and inabil ity to weight bear. On examination the leg is often shortened and externally rotated. Intracapsular fractures Subcapital, cervical, and basal fractures disrupt the blood supply to the femoral head leading to avascular necrosis. These are treated with a hemiarthroplast y. Extracapsular fractures Intertrochanteric, basal and subtrochanteric fractures do not disru pt the blood supply and therefore can be treated by \201 xation, e.g. dynamic hip screw ( DHS). Hip dislocation These are usually secondary to high-energy trauma in younger patients. They can be divided into anterior, posterior (80 acetabular margin are a common complication of posterior dislocations. % ), or central. Fractures of the Imaging Plain \201 lm (Fig. 20.11 ) \200 AP and lateral views are the \201 rst line o f investigation. \200 A fracture line, cortical or trabecular disruption may be identi \201 ed. CT \200 This should only be used to characterize complex fractures. \200 3D reconstruct ion views can aid surgical planning. MRI This is indicated where there is strong clinical concern for a femoral neck fracture bu t the radiographs are negative. 2 are radiographically occult. MRI can assess soft tissues, occult fractures, and underlying bone. % of all femoral neck fractures Bone scintigraphy Where MRI is contraindicated or not available this can be used as an alte r- native to investigate an occult femoral neck fracture. Information for the radiologist \200 Does the mechanism match the injury? \200 Does the re remain a strong clinical concern for a femoral neck fracture? SUBASH KC/NMC-15TH/2014 PROXIMAL FEMORAL FRACTURES 333 Fig. 20.11 and externally rotated left leg. Pelvic radiograph demonstrates a multisegmental fracture of the left femoral neck. An 85-year-old patient, who was found on the \202 oor with a shortened SUBASH KC/NMC-15TH/2014 334 CHAPTER 20 Trauma Knee injuries The inherent stability of the knee is dependent on the associated soft tissue s: \200 Extra-articular ligaments (medial and lateral collateral). \200 Intra-articular ligaments (anterior and posterior cruciate). \200 Menisci. Common injuries Cruciate ligament injury Injuries to these classically present as an immedi ate haemarthrosis after injury. An avulsion fracture often accompanies a rupture of one of the ligaments. \200 Fractures of the tibial spine are a consequence of avulsions of the anterior cruciate ligament. Posterior cruciate injuries are associated with an avulsion fracture, posterior to the tibial spines. A Segond fracture is a capsular avulsion fracture of the margin of the lateral tibial plateau and is strongly associated with anterior cruciate and meniscal injur ies. Meniscal injuries These classically present with locking, clicking, and effusion. The latte r becomes apparent several hours after the injury. Collateral ligament injuries These present after a blow to the knee from the side with asso ciated instability. Tibial plateau fractures Signi \201 cant injuries to the medial and lateral collateral lig aments are often associated with these fractures. \200 80 % involve the lateral plateau. \200 They may be subtle, but can be identi \201 ed on radiographs as a depression in the plateau secondary to impaction from the femoral condyle. There may be displacement of the tibial margin. Patella \200 Following a direct blow to the patella, comminuted fractures may be seen. \200 Osteochondral fractures of the articular surface may occur secondary to patella dislocation. Skyline views or MRI may be required to demonstrate this injury. Common sites are: the medial surface of the patella or the lateral femoral condyle. Imaging Plain \201 lm AP \200 This is good for assessment of the assessment of all 3 bo nes and their coronal alignment. Beware confusing a bipartite patella (characteristic position in the upper outer quadrant) with a fracture. SUBASH KC/NMC-15TH/2014 KNEE INJURIES 335 Lateral \200 This view can demonstrate evidence of an effusion or a lipohaemarthrosis (indicated by a fat- \202 uid level in the effusion). A lipohaemarthrosis may be the only plain \201 lm sign of an intra-articular fracture. Oblique or skyline views are indicated if a patellar injury is suspected. CT This is commonly used to con \201 rm subtle injuries or for surgical planning in comple x cases, e.g. tibial plateau fractures. MRI This is the modality of choice for the diagnosis of soft tissues injuries around the kn ee including; meniscal and ligament sprains and tears. Information for the radiologist \200 The mechanism of injury. \200 Surgical plan and an ticipated timescale. (a) (b) Fig. 20.12 A 25-year-old female who was on the receiving end of a 2-footed sliding tackle. a) Sagittal and b) coronal CT reformats showing an intra-articular fracture of the proximal tibia. SUBASH KC/NMC-15TH/2014 336 CHAPTER 20 Trauma Ankle trauma The ankle is a hinge joint formed by the tibia, talus, and \201 bula. The jo int is weak anteriorly and posteriorly, but reinforced by the medial collateral, lateral co llateral, and the interosseous ligaments. Clinical presentation Mechanisms of injury occur via: \200 Inversion injury (damage to la teral ligaments malleolus). \200 Eversion injury (this stresses the medial ligament an d may avulse the medial malleolus). Forced dorsi \202 exion. Common fractures Malleoli \200 These fractures are usually obvious, although both views s hould be inspected carefully, as some are only seen on one view. If a fracture is identi \201 ed then look for a 2 nd fracture or a ligamentous injury. Talus Osteochondral fractures: \200 Small talar dome impaction fractures. \200 Often oc cur during inversion. Neck of talus: \200 These have a high associated risk of avascular necrosis. Body of talus: \200 These have a risk of non-union or subsequent subtalar osteoarthritis if unrecognized. Imaging Plain \201 lm These are the main investigation of ankle injuries (if positive Ott awa ankle rules). AP mortice \200 The joint space should be uniform with a smooth surface to the talar dome. The space between distal tibia and \201 bula should not measure > 6mm. Lateral th metatarsal. This should include the calcaneus and the base of 5 CT This is used if there is a strong clinical suspicion of a fracture, but the plain \201 lms are negative, or if detailed reconstructions are required for surgical planning. MRI This is indicated for signi \201 cant ligamentous, cartilage, osteochondral, and soft tissue injuries. SUBASH KC/NMC-15TH/2014 ANKLE TRAUMA 337 Classi \201 cation The Weber \200\223AO classi \201 cation system is the most commonly us ed ankle fracture classi \201 cation system. This refers to injuries to the lateral malleo lus: \200 Type A: fracture below the ankle joint. \200 Type B: fracture at the level of the joint. \200 Type C: fracture above joint level, which tears the syndesmotic ligament s. (a) (b) Fig. 20.13 radiographs demonstrate a multisegmental fracture of the distal \201 bula abov e the level of the tibio \201 bular syndesmosis. The arrow points to a widened medial join t space. This is therefore likely to be unstable. A 25-year-old fell awkwardly whilst playing football. a) AP and b) lateral SUBASH KC/NMC-15TH/2014 338 CHAPTER 20 Trauma Calcaneal fractures The calcaneus or heel bone is the largest of the tarsal bones. It suppo rts the total body weight thereby facilitating walking. The subtalar joint (the articulatio n between the talus and the calcaneus) facilitates inversion and eversion. Clinical presentation This is the most commonly injured bone of the hind foot. Fractures ar e either following a fall from a height or stress fractures in the elderly. Fractures can be intra-articular (75 % ) or extra-articular (25 % ). The most important distinction is whether the subtalar joint is involved, due to its impact on walki ng. Imaging Plain \201 lm These are the initial investigation of choice. Lateral (Fig. This view can be carried out for either a speci \201 c calcaneal injury or a s part of the investigation for an ankle injury. Therefore it is important to always look f or a calcaneal fracture when assessing ankle radiographs. It is important to assess Boehler \200\231s angle (normal range 20 \200\22340 20.14a ) ) on the lateral view as this may be the only indication of an injury. Axial This is a speci \201 c view of the calcaneus. CT (Fig. This is used to provide detailed reconstructions of the full extent of the injury. The surgeons will particularly want to know the extent of damage to the subtalar joint. 20.14b ) MRI This is only rarely used if there is concern for major soft tissue injuries. Information for the radiologist The mechanism as injuries to the hind foot, after a fall fr om a height, should raise concern for spinal injuries. SUBASH KC/NMC-15TH/2014 CALCANEAL FRACTURES 339 (a) (b) Fig. 20.14 unable to weight bear after. a) Lateral ankle radiograph showing signi \201 can t fragmen- tation of the calcaneus. b) Axial CT image fully demonstrating the true extent o f the injury. A 20-year-old male who jumped from a second \202 oor window and was SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014 341 Chapter 21 Gastrointestinal differential diagnosis Abdominal calci \201 cation Ascites 342 Colonic dilatation 342 Pneumoperitoneum 343 Pneuma tosis intestinalis (gas in the bowel wall) Small bowel dilatation 343 Strictures 344 342 343 SUBASH KC/NMC-15TH/2014 342 CHAPTER 21 Gastrointestinal differential diagnosis Abdominal calci \201 cation Calci \201 cation seen on an abdominal radiograph may be due to calci \201 cation of normal structures, or calci \201 cation indicating pathology. Calci \201 cation of normal structures \200 Ribs (costal cartilage). \200 Mesenteric n odes. \200 Pelvic veins (phleboliths). \200 Prostate. Abnormal structures to contain calcium i.e. calcium indicates pathology: \200 Pancreas. \200 Renal parenchyma. \200 Blood vessels and aneurysms. \200 Gall bladder (e.g. porce lain gallbladder). \200 Uterus ( \201 broids). Calcium is pathological \200 Biliary calculi. \200 Renal calculi. \200 Appendicolith. \200 Bladder calculi. \200 Teratoma. Ascites \200 Cirrhosis. \200 Tumors. \200 Hypoalbuminaemia. \200 Peritonitis. \200 Increased pressure in vascular system distal to liver. \200 Lymphatic obstruction. Colonic dilatation Non-toxic (without abnormal mucosa) \200 Mechanical obstruction (e.g. carcinoma). \200 Ileus: paralytic/secondary to electrolyte imbalance. \200 Pseudo-obstr uction: signs or symptoms of LBO but no organic lesion as cause. Purgative abuse. Toxic (with mucosal abnormalities) \200 In \202 ammatory: UC. \200 Crohn \200\231s disease. \200 Pseudomembranous colitis. Ischaemic colitis. \200 Infective (e.g. dysentery). SUBASH KC/NMC-15TH/2014 SMALL BOWEL DILATATION 343 Pneumoperitoneum \200 Perforation of a gas containing viscus: Peptic ulcer. \200 Secondary to in \202 ammation, e.g. diverticulitis, toxic megacolon, necrotizing enterocolitis, appendicitis. Infarction. \200 Malignant neoplasm. \200 Obstruction. Iatrogenic. e.g. postoperative, dialysis, etc. (may take a couple of weeks to resorb, but should reduce in amount over time). Pneumomediastinum. \200 Pneumothorax (pleuroperitoneal \201 stula). \200 Per vaginum. \200 Idiopathic. Pneumatosis intestinalis (gas in the bowel wall) \200 Primary (15 % ): Pneumatosis coli. Secondary: Immunosuppressive and steroid therapy. \200 Leukemia. \200 Colitis and enteritis of any cause (UC, Crohn \200\231s, ischaemia, severe infective colitis). Collagen disorders (scleroderma). Small bowel dilatation \200 Mechanical obstruction. \200 Paralytic ileus. \200 Ischae mia. \200 Crohn \200\231s disease. \200 Radiotherapy. \200 Lymphoma. SUBASH KC/NMC-15TH/2014 344 CHAPTER 21 Gastrointestinal differential diagnosis Strictures Oesophageal Strictures of the esophagus can be separated into smooth and irregul ar, as they appear at contrast swallow studies. Smooth \200 In \202 ammatory: Peptic. \200 Scleroderma. \200 Corrosives. \200 Iatrogenic, e.g. after chronic NG tub e. Neoplastic: Carcinoma (occasionally squamous carcinoma). \200 Mediastinal tumors. \200 Leiomyoma. Achalasia. Irregular \200 Neoplastic: \200 Carcinoma. \200 Leiomyosarcoma. \200 Carcinosarcoma . \200 Lymphoma. \200 In \202 ammatory: Re \202 ux (more commonly smooth). \200 Crohn \200\231s disease. Iatrogenic: Radiotherapy. \200 Fundoplication. Small bowel \200 Adhesions. \200 Crohn \200\231s disease. \200 Ischaemia. \200 Radi ation. \200 Tumors. Large bowel \200 Neoplastic: \200 Carcinoma. \200 Lymphoma. \200 In \202 ammatory: UC, Crohn \200\231s, radiotherapy, diverticulosis. Ischaemia: Commonest site is splenic \202 exure at the vascular watershed area. Infective: \200 e.g. TB. Extrinsic masses: In \202 ammatory, tumors, endometriosis. SUBASH KC/NMC-15TH/2014 345 Chapter 22 Gastrointestinal presenting syndromes Upper abdominal pain Vomiting 348 Jaundice 350 Melaena 352 Iron de \201 ciency anemia Diar rhea 354 Abdominal distension 355 Weight loss 356 346 353 SUBASH KC/NMC-15TH/2014 346 CHAPTER 22 Gastrointestinal presenting syndromes Upper abdominal pain Differential diagnosis \200 Gastritis. \200 Stomach/duodenal ulcer ation. \200 Cholecystitis/cholangitis. \200 Pancreatitis. \200 Subphrenic abscess. \200 Viscus perforation. \200 Stomach cancer. \200 Liver cancer. \200 Pancreatic can cer. Imaging The differential diagnosis of upper abdominal pain is wide and the choice of approp riate investigation is guided by obtaining a good clinical history and examination to ident ify typical features associated with certain conditions. Investigations utilized in upper abdominal pain include plain radiography, abdominal ultrasound, OGD, and CT. OGD is not an imaging modality and is best suited to inv estigation of possible gastritis and peptic ulcer disease. Plain radiographs (erect chest radiograph and abdominal radiograph) may be helpful as the i nitial investigation to assess for intestinal obstruction or viscus perforation. They can a lso provide additional information on the presence of gallstones or renal calculi. TA ultrasonography is the investigation of choice in hepatobiliary or gallstone disease. It also provides information on other important structures within the abdomen which are inter rogated during the scan such as the kidneys, spleen, and aorta. CT is being used increasingly for de \201 nitive assessment of the abdomen either as a pri mary modality, usually when the patient is acutely unwell or as a problem-solving tool when initial investigations have either identi \201 ed an abnormality which requires further e valuation or when the patient \200\231s ailment remains unexplained. Owing to its optimal d epiction of the solid intra-abdominal viscera, small and large bowel, and vascular tree its main roles are in diagnosing acute pathology in addition to staging and follow-up of chron ic illness and malignancy. SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014 348 CHAPTER 22 Gastrointestinal presenting syndromes Vomiting Vomiting is a common and non-speci \201 c symptom. A myriad of causes can trigger the vomiting center in the brain, many of which will not require imaging. A careful histor y of the duration and type of symptoms along with the patient \200\231s age and associated symptoms will guide the differential and inform whether imaging is required. Causes \200 GI: gastroenteritis, gastric outlet obstruction, bowel obstruction, ileus, gastroparesis. In \202 ammatory: e.g. appendicitis, acute cholecystitis, pancreatitis. \200 CNS: head i njury, raised intracranial pressure, meningitis, labyrinthine neuronitis, migraine. Metabolic/endocrine: hypercalcaemia, uraemia, hyponatraemia, diabetic ketoacidosis. Drugs: chemotherapy, antibiotics, opiates, digoxin. \200 Alcohol. \200 Other: pregnancy , MI, UTI, psychogenic. Clinical presentation History \200 Distinguish true vomiting from regurgitation. \200 D uration of symptoms: acute, chronic, or recurrent. \200 Timing: relation to meals, early morning (pregnancy, raised intracranial pressure). Content of vomitus: bile, blood, coffee grounds, feces. \200 Abdominal pain, fever, diarr hea. \200 Constipation. \200 Headache, neck stiffness, focal neurology, vertigo. \200 Pregnancy symptoms, e.g. amenorrhea. \200 Weight loss. \200 Previous abdominal surgery : consider obstruction secondary to adhesions. Primary malignancy: obstruction or cerebral metastases. Clinical examination The most relevant \201 ndings to inform imaging are signs of obstruc tion (high pitched bowel sounds, peritonism or abdominal mass and signs of raised intracran ial pressure or focal neurology to indicate a CT head. Imaging The type of imaging will be guided by the differential diagnosis and the patient \200\231s age. Imaging is not indicated in many causes of vomiting, e.g. gastro- enteritis or pregnancy. The main role of imaging is to diagnose or exclude mechanical obstruction or intracranial pathology. Imaging may also play a role in diagnosing in \202 ammatory condit ions such as appendicitis. Plain \201 lm An abdominal radiograph is the \201 rst-line investigation in suspected b owel obstruction. Features include dilated bowel proximal to an obstruction with a paucity of gas distally. Look for free gas in associated perforation. SUBASH KC/NMC-15TH/2014 VOMITING 349 Ultrasound May be \201 rst-line investigation of neonates or infants with vomiting, e.g. ?pyloric stenosis or adults with features of in \202 ammatory causes, e.g. pancreatitis or cholecystitis. CT CT head is the investigation of choice in suspected neurogenic vomiting, e.g. post-head injury or in a patient with features of raised intracranial pressure or a known primary mal ignancy at risk of cerebral metastases. CT of the abdomen and pelvis is carried out in bowe l obstruction to look for the site and cause of obstruction. Other in \202 ammatory causes of vomiting such as appendicitis, pancreatitis, and cholecystitis may be detected. Fluoroscopy Upper GI contrast studies are used in suspected gastric outlet obstruction and in children. Nuclear medicine Radionuclide gastric emptying study may be used in investigation of unex- plained nausea and vomiting. SUBASH KC/NMC-15TH/2014 350 CHAPTER 22 Gastrointestinal presenting syndromes Jaundice Jaundice is clinically detectable when the serum bilirubin concentration is in exc ess of 50 mol/L (with a normal value of <1750 be due to \200\230pre-hepatic \200\231 ca uses (haemolysis of red blood cells), \200\230hepatic \200\231 causes (including congenita l syndromes, hepatitis, and cirrhosis), and \200\230post-hepatic \200\231 or obstructive c auses (obstruction of bile secretion distal to the bile canaliculi by stones, strictures, o r carcinoma). Imaging is most useful in this latter group. mol/L). It can Clinical presentation Patients may present as they notice yellow discoloration of the skin and eyes, with severe itching or with weight loss, dark urine, and steatorrhoea. Abdominal pain may be a feature, mostly in association with the more benign causes of jaundice, altho ugh not always. Alternatively, deranged liver function tests may be detected during investi gation of other condi- tions or during routine follow-up or preoperative investigation. Imaging Plain \201 lms Gallstones may be visualized in the right upper quadrant. Only 10 gallstones calcify and are radio-opaque so their absence does not exclude gallbladder patho logy. Also, gallstones are a common \201 nding within the population, such that their pre sence is not necessarily causative. Remember, there could be other \201 ndings on the pla in \201 lms which may point to the cause of jaundice such as metastatic deposits, lung ma ss, etc. % of Ultrasound The main investigation in jaundiced patients. This allows assessment of liver ar chitecture in cirrhosis, the presence of focal lesions and assessment of the biliary tree ( gallstones or bile duct obstruction with duct dilata- tion). In the case of duct dilatation , ultrasound may suggest a mass in the head of pancreas or duodenum, or \201 lling defect s within the biliary system, which will need further imaging with CT or MR cholangiopancrea tog- raphy (MRCP) depending on the clinical picture. Ultrasound is also used for imaged-gui ded liver biopsy, and may also detect additional pathology such as ascites, splenomegaly, a nd allow assessment of the portal vein in chronic liver disease. In infants, choledochal cy sts may cause obstructive jaundice or ultrasound may demonstrate a small/absent gallbladder and triangular cord sign in biliary atresia. CT Used when obstructive jaundice is present and the likely cause is a malignant process. A staging chest abdomen and pelvis CT should be performed. Nuclear medicine In infants with jaundice, a HIDA (hydroxy iminodiacetic acid) scan is used to demonstrate whether any biliary excretion of isotope occurs (it doesn \200\231t in the case of biliary atresia). SUBASH KC/NMC-15TH/2014 JAUNDICE 351 MRI MRCP should be performed when ultrasound has shown obstructive jaundice and further del ineation of the point of obstruction is needed. Most useful for stone disease, although eno ugh detail is usually present to comment on the pancreas in malignancy. This investigation allows ERCP to be reserved solely for patients who require intervention. Fluoroscopy ERCP can be used to perform spincterotomy and stone removal in the case of obst ructive jaundice following appropriate imaging. Fluoroscopic transjugular liver biopsy may be necessary if the patient \200\231s clotting cannot be corrected enough to allow safe per cutaneous biopsy. Information for the radiologist \200 Is the jaundice painful or painless? If painless and the gallbladder is palpable then malignant process is more likely than stone disease (Courvosier \200\231s law ). Do the liver function tests indicate an obstructive or hepatitic picture? \200 Are there any other features in the history to suggest stone disease versus malignant process? Are there any clues on the plain \201 lms to guide further investigation? SUBASH KC/NMC-15TH/2014 352 CHAPTER 22 Gastrointestinal presenting syndromes Melaena Melaena is the black tarry feces that are passed following GI haemor- rhage. The bl ack color occurs as the iron in hemoglobin oxidizes as it passes through the GI tract. Most ly, melaena occurs around 14 hours after bleeding has occurred as it takes around this time for oxidization of the iron to occur, and is usually due to upper GI bleeding such as from the stomach, duodenum, or small bowel (proximal to the ligament of Trietz). Clinical presentation Patients may present with symptoms and signs of anemia and have a pos i- tive fecal occult blood test. Following large bleeds, patients may present with signs of shock. The differential diagnosis of melaena is wide, encom- passing ulcer disease, varice al bleeding, neoplasm, and vascular lesions. Over the last few years the role of imaging ha s changed from being purely diagnostic to identifying the site of bleeding and underlying p athology, to playing a key role in treatment of the bleed itself. Imaging Endoscopy remains the \201 rst-line investigation for patients with acute upper G I bleeds. CT However, following a negative endoscopic study, in the presence of active bleeding, a CT A would be appropriate. Essential diagnostic tool: a rapid, non-invasive, sensitive investigation which allows precise localization of bleeding point with concurrent identi \201 cation of underlying cause and allows accurate intervention planning. Requires a bleeding rate of aro und 0.3ml/min. Imaging will show extravasation of high attenuation contrast material into t he bowel lumen.