G. Gastrointestinal System

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CLINICAL PROBLEM

INVESTIGATION

RECOMMENDATION
{GRADE}

COMMENT

Gastrointestinal Tract
Difficulty in swallowing: high dysphasia (lesion may be high or low) G01 Ba swallow and Video - Fluoroscopy Indicated [B] Video recording of swallow is essential. Webs and pouches are well demonstrated. Motility disorders which must be looked for in prone or supine position may be seen despite normal endoscopy. Subtle strictures, not seen at endoscopy, best demonstrated by marshmallow or other bolus study. Multi-disciplinary approach with speech therapist and ENT surgeon is optimal.
Difficulty in swallowing: low dysphasia (lesion will be low) G02 Ba Swallow Indicated only in specific circumstances [B] Endoscopy is requires (biopsy of strictures essential). Ba swallow used to demonstrate motility disorder or subtle stricture if endoscopy normal.
NM Specialised investigation [B] Radionuclide oesophageal transit study is indicated as an alternative non-invasive assessment of oesophageal motility
Heart Burn/Chest pain/hiatus hernia or reflux G03 Ba swallow / meal Indicated only in specific circumstances [C] Reflux is common and investigation is only indicated where lifestyle changes and empirical therapy fail. While pH monitoring is the gold standard for reflux, endoscopy alone will reliably show early changes of reflux oesophagitis and allows detection and biopsy of metaplasia.. Ba studies aimed at assessing oesophageal motility prior to anti-reflux surgery do not reliable predict post-operative dysphasia.
?Oesophageal perforation G04 CXR Indicated [B] Will be abnormal in 80% of cases, but pneumo-mediastinum only present in 60%.
Swallow Indicated [B] Swallow should be performed with water-soluble non-ionic contrast agents. it is sensitive but if no leak is visualised then proceed to immediate CT
CT Indicated [A] CT is sensitive to both the presence of perforation and for the detection of mediastinal and pleural complications.
Acute GI bleeding: haematemesis / melanea G05 AXR Not indicated [B] Of no value.
Barium Studies Not Indicated [C] Precludes angiography
Endoscopy Indicated [A] endoscopy provides diagnosis in the majority of cases of upper GI bleeding and can be used to deliver haemostatic therapy
abdominal US Indicated only in specific circumstances [B] Only useful to look for signs of chronic liver disease
NM (red cell study) Specialised investigation [B] After endoscopy. Red cell labelling can detect bleeding rates as low as 0.1 ml/min; more sensitive than angiography. Red cell study is most useful in intermittent bleeding.
Angiography Specialised investigation [B] When considering surgery or intervention (e.g. remobilisation) for uncontrollable bleeding. Angiography can accurately direct surgery and transcatheter emobilisation may be used as primary treatment.
Dyspepsia in the younger patient (e.g. under 45 yrs) G06 Imaging (Ba meal / endoscopy) Indicated only in specific circumstances [B] Most patients under 45 yrs can be treated without complex investigations and will undergo a trial of therapy (anti-ulcer or reflux). If symptoms recur or persist, the helicobacter pylori status should be assessed serologically or using the C-14 breath test. If positive, or patient has alarm symptoms (weight loss, anorexia, iron deficiency anaemia, severe pain or NSAID use), endoscopy is the investigation of choice.
Dyspepsia in the older patient (e.g. over 45 yrs) G07 Imaging (Ba meal / endoscopy) Indicated only in specific circumstances [B] Endoscopy is often the first line investigation. The main concern is the detection of early cancer, especially submucosal tumours However, Ba meal remains a reasonable alternative. The alternative investigation should be considered whenever symptoms continue after negative result.
Ulcer follow-up G08 Ba studies Not indicated [B] Scarring precludes accurate assessment. Endoscopy preferred to confirm complete healing and to obtain biopsies (e.g. Helicobacter pylori, etc.) where necessary.
NM Indicated only in specific circumstances [B] Most centres use NM studies (Carbon-14 breath test) to assess effect of treatment of Helicobacter pylori.
Previous upper GI surgery (recent) G09 Water soluble contrast medium study Indicated [B] If water soluble contrast swallow does no demonstrate a leak in the anastamotic site and there is a clinical concern, then immediate CT should be performed as it is more sensitive. Ba should not be used as the contrast agent.
Previous upper GI surgery (old) : dyspeptic symptoms G10 Ba studies Indicated only in specific circumstances [B] Gastric remnant best assessed by endoscopy (gastritis, ulceration, recurrent tumour, etc.). Cross-sectional imaging (US, CT, etc.) may be needed to assess extramural disease. Endoscopic US can demonstrate submucosal recurrence.
Previous upper GI surgery (not recent): dysmotility / obstructive symptoms G11 Ba Studies Indicated [B] Shows surgical anatomy and may demonstrate dilated afferent loop, narrowed anastamosis internal hernias, closed loops etc.
NM Specialised Investigation [B] Good method for assessment of gastric emptying, dumping and stasis.
Intestinal blood loss, chronic or recurrent

(see also N14)

G12 Ba studies Not indicated initially [B] Initial investigation is endoscopy of the upper GI tract and colon. Small bowel follow through is not sufficiently sensitive for lesions likely to cause chronic bleeding and should not be used.
Small Bowel enema Indicated [B] More sensitive than Ba follow-through for small discrete lesions. However, early results of 'capsule' endoscopy in chronic bleeding suggest that this will be the investigation of choice when small bowel strictures have been excluded.
NM Indicated [B] When all other investigations are negative, labelled red cell and / or Meckel's study may be useful in detecting and localising the site of chronic and / or recurrent bleeding.
CT Indicated [B] IV contrast enhanced CT is useful to look for lesions that may be bleeding (e.g. tumours). CTA may demonstrate bowel angiodysplasia.
Angiography Specialised Investigation [B] Angiography is sensitive for angiodysplasia (with early filling vein) and to demonstrate tumour neo-vascularity.
Acute abdominal pain
?perforation
?obstruction

(For children see section M)

G13 CXR (erect) and AXR Indicated [B]  Supine AXR usually sufficient to establish diagnosis and point to an anatomical level of obstruction.
Consider erect AXR if supine AXR normal and strong clinical suspicion of obstruction. Decubitus AXR to show free air if CXR supine.
US Indicated [C] Widely used as a survey following AXR. It is sensitive to free fluid in perforation.
CT Indicated [B] For small sealed perforations and for establishing site and cause of obstruction.

This recommendation does not apply to children.

(For acute abdominal pain in children see M37)

Small bowel obstruction: acute G14 Contrast studies Indicated only in specific circumstances [B] Frequently unhelpful
CT Indicated [B] When AXR suggests small bowel obstruction, CT confirms diagnosis, indicates level and may show cause. When AXR equivocal but small bowel obstruction suspected clinically, volume challenge (i.e. CT with water or methylcellulose ingestion) may be required for complicated abdominal surgery.
Small bowel obstruction: chronic or recurrent G15 Small bowel Ba enema Indicated [B] Will reveal presence and level of obstruction in most cases and may suggest a cause.
CT Indicated [B] Performed with or without volume challenge. CT will be diagnostic as for small bowel enema, but may be a better guide to management in complex cases e.g. in patients with a previous malignancy or following complicated abdominal surgery.
Small bowel disease suspected (e.g. Crohn's disease) G14 Ba small bowel meal Indicated [B] A useful survey examination for the diagnosis of small bowel disease, including Crohn's disease
Ba small bowel enema Indicated [B] This is the investigation of choice to establish extent of disease prior to surgery, in cases where fistula is suspected, and to diagnose the cause of obstructive symptoms in patients with known Chron's disease.
US/CT/MRI Specialised Investigation [B] Use of these techniques is evolving e.g. in assessment of disease activity, and they are particularly useful to assess extramural complications
NM (white cell study) Specialised investigation [B] Labelled white cell scintigraphy reveals activity and extent of disease. Complementary to Ba studies.
?Large bowel tumour or
?inflammatory bowel disease: pain, bleeding, change in bowel habit, etc.
G15 Ba enema Indicated [B] N.B. Double contrast Ba is only useful if the bowel is properly prepared. Furthermore all patients should undergo rectal examination to assess suitability for Ba enema and to exclude a low rectal tumour. Good practice requires a sigmoidoscopy before Ba enema. Defer Ba enema for 7 days after full thickness biopsy via a rigid sigmoidoscope. Biopsies taken during flexible sigmoid-oscopy are usually superficial and the risk of subsequent perforation is low (ideally delay 48 hrs). Some centres use colonoscopy initially, reserving Ba enema for difficult or incomplete examinations. Some centres use CT for the frail elderly patient. Although the irritable bowel syndrome is the commonest cause of a change in bowel habit, Ba enema or colonoscopy is needed to exclude other causes.
Large bowel obstruction: acute G16 Enema Specialised investigation [B] Single contrast (ideally water soluble contrast medium) study can show narrowed area and exclude 'pseudo-obstruction'. Some centres use CT which can point to the likely cause.
Inflammatory bowel disease of colon:
acute exacerbation
G17 AXR Indicated [B] Often sufficient for evaluation.
NM (white cell study) Indicated [B] Labelled white cell study best exam-will reveal activity and extent of disease.
Ba enema Not indicated routinely [B] Ba enema is dangerous when toxic megacolon present; unprepared enema in selected cases after discussion with radiologists.
Inflammatory bowel disease of colon: long-term follow-up G18 Ba enema Not indicated routinely [B] Colonoscopy follow-up preferred to identify developing carcinoma in those at high risk, although Ba enema is still often used, particularly after complex intestinal surgery. Likewise Ba enema preferred for evaluating fistulae etc.
General Abdominal Problems
Acute abdo pain; (warranting hospital admission and surgical consideration) G19 AXR plus erect CXR Indicated [B] Local policy will determine strategy. Supine AXR (for gas pattern, etc.) is usually sufficient. Erect AXR not indicated routinely. Increasing use of CT as a 'catch-all' investigation here.
Palpable mass G20 AXR Not indicated [C]  
US Indicated [B] US usually solves the problem and is very reliable in thin patients, right upper quadrant and pelvis.
CT Indicated [A] CT is an alternative and useful to exclude a lesion; particularly good in fat patients.
Malabsorbtion G21 Ba study of small bowel Not indicated routinely [B] Imaging is not required for the diagnosis of coeliac disease but may be indicated for jejunal diverticulosis or when biopsy is normal/equivocal. CT may be better if lymphoma suspected.
NM Specialised investigation [B] Numerous NM investigations available which should establish presence of malabsorption. Some of these are non-radiological (e.g. breath test).
?Appendicitis G22 Imaging Not indicated routinely [C] Appendicitis is usually a clinical diagnosis. Imaging (e.g. US with graded compression) can help in equivocal cases or in differentiation from gynaecological lesions. So too can NM (white cell study) and focussed appendix CT (FACT). US recommended in children and young women.
?Constipation

(For Children see Section M)
G23 AXR Not indicated routinely [C] Many normal adults show extensive faecal material; although this may be related to prolonged transit time it is impossible to assess significance on AXR alone. But AXR can help certain specialists (e.g. geriatricians) in refractory cases.
?Abdominal sepsis; pyrexia of unknown origin (PUO) G24 US or CT or NM Indicated [C] Seek radiological advice; much depends on local availability and expertise. US often used first (speed, cost) and may be definitive, particularly when there are localising signs; especially good for subphrenic/subhepatic spaces and pelvis. CT probably best test overall: infection and tumour usually identified and excluded. Also allows biopsy of nodes or tumour and drainage of collections (especially recent post-operative). NM particularly good when there are no localising features: labelled WBC good for chronic post-operative sepsis; gallium will accumulate at sites of tumour (e.g. lymphoma) and infection.
Liver, Gallbladder & Pancreas
?Hepatic metastases G25 US
CT or MRI
Indicated Specialised investigation [B]
[B]
The majority of metastases will be demonstrated by US which also allows biopsy. US should be the initial investigation but metastases may show the same reflectivity as the hepatic parenchyma and thus be missed. Hence: CT/MRI used for further exclusion, where US equivocal or surprisingly normal and where full staging is needed or hepatic resection is planned (see also Cancer L13). Recent interest in dual phase spiral CT. MRI being increasingly used here. NM no longer used for this clinical problem.
?Hepatic haemangioma (e.g. on US) G26 MRI or CT Indicated [B] Both MRI and CT reliably show further characteristic features of haemangioma and many other solitary hepatic lesions.
NM (red cell study) Specialised investigation [B] Not often needed nowadays.
Jaundice G27 US Indicated [B] Sensitive for bile duct dilatation. But dilatation may be subtle in early obstruction and sclerosing cholangitis. Shows gallstones and most forms of hepatic disease. US also shows the level and cause of any obstruction to common bile duct. Discuss subsequent investigations (CT, ERCP, MRCP, etc.) with radiologist.
?Biliary disease, (e.g. gallstones) G28 AXR Not indicated routinely [C] Plain XRs only show about 10% of gallstones.
US Indicated [B] US allows evaluation of other organs too. Cholecystography is now rarely needed (e.g. poor views at US). CT/endoscopy may be needed for further delineation. Increasing interest in MRCP.
NM Specialised investigation [B] Biliary scintigraphy shows cystic duct obstruction in acute cholecystitis. Also useful in chronic cholecystitis.
Pancreatitis: acute G29 AXR Not indicated routinely [C] Unless diagnosis in doubt; then AXR needed to exclude other causes of acute abdo pain (see G19). Some patients presenting with acute pancreatitis have underlying chronic pancreatitis which may cause calcification evident on AXR.
US Indicated [B] To show gallstones and to diagnose and follow pseudocyst development, especially good in thin patients.
CT Not indicated routinely [B] Reserved for clinically severe cases (to assess extent of necrosis), in patients who do not improve on treatment or if there is uncertainty as to the diagnosis. Some centres use MRI, especially if repeated follow-up likely.
Pancreatitis: chronic G30 AXR Indicated [B] To show calcification.
US or CT Indicated [B] US may be definitive in thin patients; CT will show calcification to good effect.
ERCP or MRCP Specialised investigation [C] ERCP shows duct morphology, but considerable risk of acute pancreatitis. Hence current interest in MRCP.
Post-operative biliary leak G31 NM Indicated [C] US will usually have shown the anatomy of the collections, etc. NM study (HIDA) will show activity at site of leak. ERCP will show the anatomy of the leak and may allow intervention (e.g. stent).
?Pancreatic tumour G32 US
CT
Indicated
Indicated
[B]
[B]
Especially in thin patients and for lesions in the head and body. Increasing use of endoscopic and laparoscopic US. CT (or MRI) good in the fatter patient and where US equivocal or where precise staging needed. ERCP/MRCP may also be indicated.
?Insulinoma G33 Imaging Specialised investigation [B] When biochemical tests are convincing. MRI emerging as the best examination although arterial phase spiral CT promising. Most centres seek two positive investigations before surgery (out of CT/NM/MRI/angiography). Endoscopic and intra-operative US also useful.

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