ANA 412 ABDOMINAL IMAGING PowerPoint presentation

An anatomy presentation

1. BUI DEPARTMENT OF ANATOMY ANA 412 RADIOLOGICAL ANATOMY TOPIC: ABDOMINAL IMAGING DR. (Mrs.) H. B. AKPAN Associate Professor of Anatomy 1

2. ABDOMINAL IMAGING Imaging has become a very useful tool in evaluating abdominal pathology. Requires a good knowledge of the indications for the proper management of the patient with abdominal pathology, in terms of choosing the correct technique for a particular clinical situation, to prevent the overuse of imaging techniques and to prevent misdiagnosis of disease and incorrect therapy resulting from inappropriate imaging. 2

3. IMAGING MODALITIES Ultrasound The use of ultrasound contrast agents The use of computed tomography Magnetic resonance imaging X-ray imaging 3

4. IMAGING MODALITIES Ultrasound, which on its own can lead to an accurate diagnosis, plays a pivotal role in the management of abdominal pathology. The use of ultrasound contrast agents has significantly improved ultrasound diagnostic capacities in both hepatic and non-hepatic pathology. The use of computed tomography should be limited due to the potential harmful side effects of ionizing radiation, but it has established roles in evaluating severe abdominal traumatic and non-traumatic emergencies as well as in staging oncologic patients. Magnetic resonance imaging has very limited utility in abdominal emergencies due to difficulty of accessing the scanner and the long duration of the examination compared to computed tomography or ultrasound. 4

5. IMAGING MODALITIES Magnetic resonance imaging has well-established clinical roles particularly for evaluating diffuse or focal hepatic pathology, benign and malignant bile duct pathology, pancreatic tumors, inflammatory bowel disease and rectal tumors. 5

6. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Abdominal emergencies (non-traumatic) First-line imaging technique Technique of choice if US is inconclusive Can be used, as an alternative to CT in selected cases (e.g. suspicion of acute appendicitis), especially in children or young patients Abdominal emergencies (traumatic) First-line imaging technique in low-energy trauma limited to the abdomen; FAST technique for the detection of hemoperitoneum, particularly useful in unstable patients Improves the sensitivity of US in detecting parenchymal trauma and active hemorrhage First-line imaging technique in high-energy trauma 6

7. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Jaundice First-line imaging technique. Confirms the obstructive cause of jaundice by showing bile duct dilatation Can be used as a substitute if MRI is not available. Low sensitivity for bile duct calculi Technique of choice if US is inconclusive Urinary symptoms First-line imaging technique. Confirms the presence of hydronephrosis Technique of choice for the diagnosis of renal or ureteral calculi 7

8. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Palpable abnormality (abdominal mass or organomegaly) First-line imaging technique for confirming hepato- or splenomegaly. Can be used to exclude an abdominal mass in order to avoid excessive irradiation by CT Technique of choice for characterizing an abdominal mass discovered by US or clinical examination. Can be used as a substitute for CT in selected cases. Technique of choice for characterizing pelvic masses. Elevated liver enzymes Imaging technique of choice for diagnosing and characterization of diffuse liver disease Complementary to US; can be used to quantify diffuse liver disease 8

9. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Staging and evaluation of already known oncologic disease Used in the characterization of indeterminate liver lesions seen on CT Technique of choice, both for baseline imaging and also for follow-up Used complementary to CT for the characterization of indeterminate lesions, particularly focal liver lesions Evaluation of suspected congenital abnormalities First-line imaging technique, both ante-and postnatal Used in the characterization of complex urinary tract malformations Better characterization of abnormalities, incompletely evaluated by US. Can be used both ante-and postnatally 9

10. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Pre- and post-transplantation evaluation Can be used in the follow-up of transplanted patients in order to avoid excessive irradiation Improves US sensitivity in depicting vascular complications in the transplanted patient Technique of choice due to its better suitability in assessing vascular structures 10

11. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Guiding of interventional procedures Technique of choice Can be used to improve US-guided procedures (e.g. avoid the punction of the necrotized area in necrotic tumors) Second-line technique in cases when US cannot guide the procedure (lesion not identifiable by US, or vascular/digestive interpositions) Evaluation of peritoneal and retroperitoneal fluid First-line imaging technique, both ante-and postnatal Used in the characterization of complex urinary tract malformations Better characterization of abnormalities, incompletely evaluated by US. Can be used both ante-and postnatally 11

12. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Postoperative complications First-line imaging technique Can be used for better characterization of abnormalities, such as collections or free fluid, discovered by ultrasound, for characterization of inconclusive US findings or in cases of discrepancy between US and the clinical status of the patient Follow-up of liver cirrhosis and characterization of liver nodules in the cirrhotic liver First-line imaging technique, used for the detection of liver nodules on the cirrhotic liver Characterization of liver nodules discovered by routine US Characterization of liver nodules discovered by routine US Characterization of liver nodules discovered by routine US 12

13. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Evaluation of abdominal vessels Can be used in the follow-up of ectatic abdominal aorta to avoid over-irradiation Technique of choice for the initial characterization and follow-up of abdominal aortic aneurysms Characterization of incidentally discovered focal liver lesions In experienced centers, it can represent the first-line imaging technique for characterization of focal liver lesions Substitute to MRI in cases when MRI is not available or not feasible Technique of choice in cases of inconclusive CEUS findings Perianal fistulas Technique of choice for the evaluation of perianal fistulas 13

14. Indications for a given imaging modality as per the category of abdominal pathology Liver infections First-line imaging technique for the detection of liver abscess or hydatid cyst It can be used, as a second-line imaging technique for the differentiation between infectious lesions and other focal liver lesions It can be used, as a second-line imaging technique for the differentiation between infectious lesions and other focal liver lesions Evaluation of pancreatic tumors Endoscopic US can be used complementary to CT as a second-line technique to evaluate inconclusive CT findings Technique of choice for staging pancreatic tumors Technique of choice in cases of inconclusive CEUS findings 14

15. Indications for a given imaging modality as per the category of abdominal pathology Ultrasound CEUS CT MRI Inflammatory bowel disease (IBD) US and MRI have complementary roles in the initial evaluation and in the subsequent follow-up of patients with inflammatory bowel disease CT can be used as a substitute for MRI due to its better spatial resolution; its usage should be limited to cases when MRI is not available or not feasible due to the fact that patients with IBD are in most cases adolescents or young adults and it is recommended to avoid irradiation in those patients Local staging of rectal tumors Endoscopic US can be used complementary to MRI for the characterization of rectal wall invasion (differentiation between T1/T2/T3a tumors) 15

16. Indications for abdominal ultrasound/or Retroperitoneum Abdominal, flank, and/or back pain Signs or symptoms that may be referred from the abdominal and/or retroperitoneal regions, such as jaundice or hematuria Palpable abnormalities, such as an abdominal mass or organomegaly Abnormal laboratory values or abnormal findings on other imaging examinations suggestive of abdominal and/or retroperitoneal pathology Follow-up of known or suspected abnormalities in the abdomen and/or retroperitoneum Evaluation of cirrhosis, portal hypertension, and transjugular intrahepatic portosystemic shunt (TIPS) stents; screening for hepatoma; and evaluation of the liver in conjunction with liver elastography Abdominal trauma 16

17. Indications for abdominal ultrasound/or Retroperitoneum Search for metastatic disease or an occult primary neoplasm Evaluation of urinary tract infection and hydronephrosis Evaluation of uncontrolled hypertension and suspected renal artery stenosis Search for the presence of free or loculated peritoneal and/or retroperitoneal fluid Evaluation of suspected congenital abnormalities Evaluation of suspected hypertrophic pyloric stenosis, intussusception, necrotizing enterocolitis, or any other bowel abnormalities Pretransplantation and posttransplantation evaluation Planning for and guiding an invasive procedure 17

18. Indications for abdominal CT and computed tomography (CT) of the pelvis Evaluation of abdominal, flank, or pelvic pain, including evaluation of suspected or known urinary calculi and appendicitis Evaluation of abdominal or pelvic trauma Evaluation of renal and adrenal masses and of urinary tract abnormalities with CT urography Evaluation of known or suspected abdominal or pelvic masses or fluid collections, including gynecological masses Evaluation of primary or metastatic malignancies, including lesion characterization (e.g. focal liver lesion), staging, and treatment monitoring Surveillance following locoregional therapies in abdominal malignancies, including percutaneous ablation, intra-arterial therapies ( transarterial chemoembolization, selective internal radiation therapy), and targeted image-guided radiation therapy 18

19. Indications for abdominal CT and computed tomography (CT) of the pelvis Assessment for recurrence of tumors following surgical resection Detection of complications following abdominal and pelvic surgery, e.g. abscess, lymphocele, radiation change, and fistula/sinus tract formation Evaluation of diffuse liver disease (e.g. cirrhosis, steatosis, iron deposition disease) and biliary system, including CT cholangiography) Evaluation of abdominal or pelvic inflammatory processes, including inflammatory bowel disease, infectious bowel disease and its complications, without or with CT enterography Assessment of abnormalities of abdominal or pelvic vascular structures; noninvasive angiography of the aorta and its branches and noninvasive venography Treatment planning for radiation and chemotherapy and evaluation of tumor response to treatment, including perfusion studies Pre- and post-transplant assessment 19

20. Indications for abdominal CT and computed tomography (CT) of the pelvis Clarification of findings from other imaging studies or laboratory abnormalities Evaluation of known or suspected congenital abnormalities of abdominal or pelvic organs Evaluation for bowel obstruction or Gl bleeding Screening and diagnostic evaluation for colonic polyps and cancers with CT colonography Guidance for interventional or therapeutic procedures within the abdomen or pelvis Follow-up evaluation after interventional or therapeutic procedures within the abdomen or pelvis, including abscess drainage 20

21. Indications for abdominal CT and computed tomography (CT) of the pelvis CT has some disadvantages: The patient needs to be hemodynamically stable and able to lie still for the examination; It may utilize iodinated contrast media; It involves radiation exposure. Patient undergoing computed tomography (CT) scan. 21

22. Indications for abdominal MRI (excluding / or including the liver ) Liver Detection of focal hepatic lesions Focal hepatic lesion characterization, e.g. cyst, focal fat, hemangiomas, and vascular malformations, hepatocellular carcinoma (HCC), hepatoblastoma, metastasis, cholangiocarcinoma, focal nodular hyperplasia, and hepatic adenoma Evaluation for known or suspected metastasis Evaluation of vascular patency, including Budd-Chiari and portal vein thrombosis Evaluation of chronic liver disease, such as hemochromatosis, hemosiderosis, or steatosis Evaluation of cirrhotic liver and HCC surveillance Patient undergoing nuclear medicine procedure. 22

23. Indications for abdominal MRI (excluding / or including the liver ) Liver Detection of focal hepatic lesions Clarification of findings from other imaging studies, laboratory abnormalities, or alternative imaging for contraindications to CT scans Evaluation of infection Potential liver donor evaluation, liver resection evaluation, liver transplant evaluation, and evaluation of postsurgical complications Evaluation of tumor response to treatment, e.g. image-guided liver interventions/tumor ablation, chemoembolization, radioembolization, chemotherapy, radiotherapy, or surgery Evaluation of known or suspected congenital abnormalities Informing or guiding clinical decision-making and treatment planning 23

24. Indications for abdominal MRI Pancreas Detection and preoperative assessment of pancreatic neoplasms Characterization of indeterminate lesions and/or unexplained enlargement detected with other imaging modalities Identification of causes of pancreatic duct obstruction, including calculi, stricture, or mass Detection and characterization of pancreatic duct anomalies Evaluation of pancreatic or peripancreatic fluid collections or fistulae Evaluation of chronic pancreatitis, including assessment of pancreatic exocrine function Evaluation of complicated acute pancreatitis and associated complications Postoperative treatment/follow-up after pancreatic surgery 24

25. Indications for abdominal MRI Spleen Characterization of indeterminate lesions detected with other imaging modalities Detection and characterization of suspected diffuse abnormalities of the spleen Evaluation of suspected accessory splenic tissue Kidneys, ureters and retroperitoneum Detection of renal tumors Characterization of indeterminate lesions detected with other imaging modalities Preoperative assessment of renal neoplasms to include evaluation of the arterial supply, renal vein, and inferior vena cava Evaluation of the urinary tract for abnormalities of anatomy or physiology (MR urography) 25

26. Indications for abdominal MRI Kidneys, ureters and retroperitoneum cont’d Post-procedure surveillance after renal tumor ablation or surgical extirpation via partial or complete nephrectomy Evaluation of ureteral abnormalities Evaluation of suspected retroperitoneal fibrosis and other benign lesions Characterization and staging of retroperitoneal malignant neoplasms Evaluation or follow-up of lymphadenopathy Surveillance imaging of the upper urinary tract in patients with urothelial carcinoma Characterization of complex congenital anomalies Identification of causes of urinary tract obstruction 26

27. Indications for abdominal MRI Adrenal glands Detection of suspected pheochromocytoma and functioning adrenal adenoma Characterization of indeterminate lesions detected with other imaging modalities Staging of malignant adrenal neoplasms Detection and characterization of congenital anomalies Vascular Diagnosis and/or assessment of the following vascular abnormalities: 1. Aneurysm of the aorta and major branch vessels; 27

28. Indications for abdominal MRI Vascular cont’d II. Stenosis or occlusion of the aorta and major branch vessels resulting from atherosclerotic disease, thromboembolic disease, or large vessel vasculitis; III. Dissection of the aorta; IV. Vascular malformation and arteriovenous fistula; V Portal, mesenteric or splenic vein thrombosis; VI. Inferior vena cava (IVC), pelvic vein, gonadal vein, renal vein or hepatic vein thrombosis Vascular evaluation in one of the following clinical scenarios: 28

29. Indications for abdominal MRI Vascular cont’d 1. Lower extremity claudication; II. Known or suspected renovascular hypertension; III. Known or suspected chronic mesenteric ischemia; IV Hemorrhagic hereditary telangiectasia; V Known or suspected Budd-Chiari syndrome; VI. Portal hypertension; VII. Known or suspected gonadal vein reflux 29

30. Indications for abdominal MRI Vascular Pre procedure assessment for the following: 1. Vascular mapping prior to living organ donation a) Liver b) Kidney c) Pancreas d) Combined organ transplant; II. Assessment of renal vein and IVC patency in the setting of renal malignancy or neoplasm; III. Vascular mapping prior to placement of or surgery on a transjugular intrahepatic portosystemic shunt (TIPS); IV Vascular mapping prior to resection of abdominal and pelvic neoplasms; V Vascular mapping prior to uterine fibroid embolization; VI. Vascular mapping prior to hepatic bland embolization, chemoembolization, and radioembolization procedures; VII. Vascular mapping prior to tissue grafting 30

31. Indications for abdominal MRI Vascular cont’d Post procedure assessment for the following: 1. Evaluation of organ transplant vascular anastomoses (hepatic, renal, and pancreatic); II. Detection of suspected leak following aortic aneurysm surgery or MR-compatible aortic stent graft placement; III. Evaluation of ovarian artery collateral flow following uterine fibroid embolization 31

32. Indications for abdominal MRI Bile ducts and gallbladder Detection, staging, and post-treatment follow-up of bile duct and gallbladder cancer Detection of bile duct or gallbladder stones Evaluation of bile duct dilation and/or narrowing Evaluation of suspected congenital abnormalities of the gallbladder or bile ducts Detection and anatomic delineation of bile leaks 32

33. Indications for abdominal MRI Gastrointestinal tract and peritoneum Preoperative assessment of gastric neoplasms Detection of small bowel neoplasms Assessment of inflammatory disorders of the small or large bowel and mesentery (including MR enterography); Assessment of peritoneal adhesive disease Detection and evaluation of primary and metastatic peritoneal or mesenteric neoplasms Detection and characterization of intra-abdominal fluid collections, as well as follow-up after percutaneous or surgical drainage Evaluation and follow-up of lymphadenopathy 33

34. Indications for abdominal MRI Other applications Imaging follow-up of abnormalities of the abdomen deemed indeterminate on initial MRI and for which surgery is not advised Detection and characterization of extraperitoneal neoplasms other than above Evaluation of the abdomen as an alternative to computed tomography (CT) when radiation exposure is an overriding concern in susceptible patients, such as pregnant or pediatric patients, or in patients with a contraindication to iodinated contrast agents Assessment of treatment response to medical therapy of malignant neoplasms of the abdomen 34

35. Indications for abdominal MRI Other applications Determining the organ of origin of an indeterminate (benign or malignant) lesion in the abdomen when the origin is not obvious from other imaging modalities Identification and characterization of vascular malformations Evaluation of abdominal wall abnormalities not adequately assessed by other imaging modalities Assessment of traumatic injury of the abdomen when CT is contraindicated 35

36. Abdominal radiography/x-ray/AXR Indications Abdominal x-rays (AXR) are a plain x-ray of the abdomen. Although it has lower sensitivity and specificity than a CT of the abdomen, it still serves a role as an adjunct or optional test and can be used to diagnose: • The presence of obstruction (enlarged bowel with trapped air) • Perforation (free air outside of the bowel wall) in conditions such as perforated duodenum secondary to an ulcer • Organomegaly (increased solid organ size) • The presence of stones and constipation. 36

37. Abdominal radiography/x-ray/AXR Indications Other uses for abdominal radiography include: A preliminary evaluation of bowel gas in an emergent setting A negative study in a low pretest probability patient may obviate the need for a CT study and therefore lower radiation dose Evaluation of radiopaque tubes and lines Evaluation for radiopaque foreign bodies Evaluation for postprocedural intraperitoneal/retroperitoneal  free gas Monitoring the amount of bowel gas in  postoperative ileus Monitoring the passage of contrast through the bowel Colonic transit studies Monitoring  renal calculi 37

38. Abdominal radiography Contraindications • pregnancy is a relative contraindication to the use of ionizing radiation o non-ionizing studies (e.g. ultrasound or MRI) could be tried first o abdominal radiographs administer a much lower radiation dose than CT 38

39. Abdominal radiography Projections Standard projections • AP supine view o can be performed as a standalone projection or as part of an acute abdominal series • PA erect view o often taken with the supine view. When used together it is a valuable projection in assessing gas-fluid levels, and free gas in the abdominal cavity. • KUB view o used to visualize calculi within the urinary system (kidneys, ureters, bladder) 39

40. Abdominal radiography Additional projections Generally, plain radiograph examination of the abdomen comprises an AP supine and PA erect view, supplemented by a number of additional views as clinically indicated. • Lateral decubitus view o performed as an alternative to the PA erect view to assess for free gas in the abdominal cavity • Lateral view o often used as a problem solving view during the identification and localization of foreign bodies 40

41. Abdominal radiography Additional projections cont’d • PA prone view o performed if the patient is unable to lie supine • Dorsal decubitus view o used when it is unsafe to perform both a PA erect or a lateral decubitus view, this projection requires no patient movement. • Oblique views o used in barium studies and the location of foreign bodies and/or lines such as a Tenckhoff catheter 41

42. Abdominal radiography Procedure Preprocedural evaluation The patient should be gowned with minimum clothing. Radiopaque materials (zippers, belts, etc.) should be removed. If relevant, enteric tube suction should be avoided before the study. Ideally, the patient's bladder should be emptied as well. Technique Abdominal radiographs may be obtained in the radiology department or may be performed portably. Views should generally include either the diaphragm or inferior pubic ramus. Gonadal shielding may be provided for men. Portable abdominal radiographs may be necessary due to patient immobility but are of much poorer quality. Radiologist preparing patient for an abdominal x-ray. 42

43. Abdominal radiography Procedure kilovoltage peak (kVp) The kVp of the x-ray beam may be altered in order to bring out different aspects of the abdominal radiograph: • Lower kVp offers greater tissue contrast and better visualization of gas, but there is decreased penetration of the x-ray beam • Higher kVp may be useful for evaluation of radiopaque objects (contrast, tubes, lines, etc.) 43

44. Abdominal radiography The Equipment The equipment typically used for an abdominal x-ray consists of a table on which the patient lies and a large x-ray machine suspended from the ceiling. The x-ray film or digital recording plate is held in a drawer under the table. Compact, portable x-ray machines can be taken to the patient in a hospital bed or the emergency room. The x-ray tube is connected to a flexible arm. The technologist extends the arm over the patient and places an x-ray film holder or image recording plate under the patient. 44

45. Abdominal radiography - Examples Figure 1: AP supine view Figure 2: PA erect view 45

46. Abdominal radiography - Examples Figure 3: lateral decubitus view Fig 4: annotated normal abdominal radiograph 46

47. Abdominal radiography - Examples Fig 4: annotated normal abdominal radiograph 47 Purple : Liver Pink : Spleen Green : Left 11th rib Orange : Kidneys Red : Psoas muscle Brown : Spinous process of L1 Light Blue : Pedicles of L3 Black : Transverse processes of L3 Yellow : Vertebral body of L4 Dark Blue : Urinary bladder Dotted Green : Usual path of the ureter (not usually visible) Dotted White : Left sacroiliac joint

48. Abdominal radiography - Examples Fig 5: annotated normal abdominal radiograph 48 Annotated x-ray of the abdomen highlighting the key anatomical structures that are often visualized

49. Abdominal radiography Benefits • Abdominal x-ray imaging is a painless, minimally invasive procedure with rare complications. • Radiology examinations can often provide enough information to avoid more invasive procedures. • X-ray equipment is relatively inexpensive and widely available in emergency rooms, doctors’ offices, ambulatory care centers, nursing homes, and other locations. This makes it convenient for both patients and doctors. 49

50. Abdominal radiography Benefits cont’d • Because x-ray imaging is fast and easy, it is particularly useful in emergency diagnosis and treatment. • No radiation stays in your body after an x-ray exam. • X-rays usually have no side effects in the typical diagnostic range for this exam. 50

51. Abdominal radiography Risks • There is always a slight chance of cancer from excessive exposure to radiation. However, given the small amount of radiation used in medical imaging, the benefit of an accurate diagnosis far outweighs the associated risk. • *The radiation dose for this procedure varies. • *Women should always tell their doctor and x-ray technologist if they are pregnant. 51

52. Abdominal radiography Risks – Radiation Dose 52

53. Abdominal radiography - Interpretation Best done by following a systematic and well structured approach Decreases the risk of missing pathology. Example: The BBC approach: • B owel and other organs: small bowel, large bowel, lungs, liver, gallbladder, stomach, psoas muscles, kidneys, spleen and bladder. • B ones: ribs, lumbar vertebrae, sacrum, coccyx, pelvis and proximal femurs. • C alcification and artefact (e.g. renal stones) 53

54. Abdominal radiography - Interpretation Small and large bowel Helpful clues: • The small bowel usually lies more centrally, with the large bowel framing it. • The small bowel’s mucosal folds are known as valvulae conniventes and are visible across the full width of the bowel. • The large bowel wall features pouches or sacculations that protrude into the lumen, known as haustra . In between the haustra are spaces known as plicae semilunaris. The haustra are thicker than the valvulae conniventes of the small bowel and typically do not appear to completely traverse the bowel. ** 54

55. Abdominal radiography - Interpretation Small and large bowel Helpful clues: • Faeces have a mottled appearance and are most often visible in the colon, due to trapped gas within solid faeces . Bowel diameter The upper limits for the normal diameter of different bowel segments are as follows: • Small bowel: 3cm • Colon: 6 cm • Caecum: 9 cm This is often referred to as the ‘3/6/9 rule’. 55

56. Abdominal radiography - Interpretation A normal abdominal X-ray showing large bowel (white arrow) framing the small bowel (black arrow) 56

57. Abdominal radiography - Interpretation Rigler’s (double wall) sign in pneumoperitoneum • Thumbprinting : mucosal thickening of the haustra due to inflammation and oedema causing them to appear like thumbprints projecting into the lumen. • Lead-pipe (featureless) colon : loss of normal haustral markings secondary to chronic colitis. • Toxic megacolon : colonic dilatation without obstruction associated with colitis. 57

58. Abdominal radiography - Interpretation Other organs and structures • Lungs: inspect the lung bases for pathology (e.g. consolidation) as abdominal pain can, in some cases, be caused by basal pneumonia. • Liver: a large right upper quadrant structure. • Gallbladder: rarely visible on an abdominal X-ray, however, you should quickly inspect for calcified gallstones and cholecystectomy clips. • Stomach: visible between the left upper quadrant and midline, containing a variable amount of air. • Psoas muscles: the lateral edge is marked by a relatively straight line either side of the lumbar vertebrae and sacrum. • Kidneys: both are often visible, the right kidney is lower than the left due to the presence of the liver on the right. • Spleen: located in the left upper quadrant, superior to the left kidney. • Bladder: has a variable appearance depending on its fullness 58

59. Abdominal radiography - Interpretation Lots of bones are visible on an abdominal X-ray Important to identify each for use in screening for pathology. In addition, bones on an abdominal X-ray provide useful landmarks which allow you to approximate the location of soft tissue structures (e.g. the ischial spines are the usual level of the vesico-ureteric junction). Bony structures commonly visible on abdominal X-ray include: • Ribs • Lumbar vertebrae • Sacrum • Coccyx • Pelvis • Proximal femurs A wide range of bony pathologies can be identified on abdominal X-ray including fractures, osteoarthritis, Paget’s disease and bony metastases. 59

60. Abdominal radiography - Interpretation Calcification and artefact Various high density (white) areas of calcification or artefact may be noted on abdominal X-ray including: • Calcified gallstones in the right upper quadrant • Renal stones/staghorn calculi • Pancreatic calcification • Vascular calcification • Costochondral calcification • Contrast (e.g. following a barium meal) • Surgical clips • Jewellery 60

61. ASSIGNMENT Abdominal aorta aneurysm/Ectatic abdominal artery Ultrasound assessment of abdominal aorta Pelvic-ureteric junction obstruction Vesico-ureteric junction obstruction Tenckhoff catheter Urolithiasis Radiation Safety in imaging Radiation dose in imaging Foreign bodies in Gastrointestinal and Genitourinary Tracts (imaging) Colonic transit study Adynamic ileus Pneumoperitoneum Details of the proce dures of abdominal X-ray and MRI 61