# Introduction

INTRODUCTION

Appropriate surgical management of  the patient relies on correct diagnosis. While clinical symptoms and signs may provide a firm diagnosis in some cases, other conditions will require the use of  supplementary investigations including imaging techniques. The number and scope of  imaging tech niques available to the surgeon have dramatically increased within a generation, from a time when radiographs alone were the mainstay of  investigation. The development of  ultrasound and colour Doppler , computed tomography (CT) and magnetic resonance imaging (MRI) has enabled the surgeon to make increasingly confident diagnoses and has reduced the need for diagnostic surgical techniques such as explorative laparotomy . As a basic principle, the simplest, cheapest test should be chosen hoping that it will answer the clinical question. This necessitates knowledge of  the potential complications and diagnostic limitations of  the various methods. For example, in a patient pr esenting with the clinical features of  biliary colic, an ultrasound examination alone may give enough informa tion to enable appropriate surgical management. In more com plex cases, it may be more e ffi cient to opt for a single, more expensive investigation, such as CT , rather than embarking on multiple simpler and cheaper investigations that may not yield the answer. The choice of technique is often dictated by equipment availability , expertise and cost, as well as the clinical presentation. However, it must be emphasised that, not infre quently , the most valuable investigation is prior imaging; this not only reduces the cost and the amount of radiation a patient receives but v ery often improves patient care. Christian Johann Doppler , 1803–1853, Professor of  Experimental Physics, Vienna, Austria, enunciated the ‘Doppler principle’ in 1842. 

The principles of different imaging techniques and
•
their advantages and disadvantages in different clinical
scenarios
The role of imaging in directing treatment in various
•
surgical scenarios

Introduction

Trauma remains a major cause of  mortality and morbidity in - all age groups. Presented with a multiply injured patient, rapid and e ff ective investigation and treatment are required to maxi - mise the chances of  survival and to reduce morbidity . Imaging - plays a major role in this assessment and in guiding treatment. As with the clinical assessment, imaging is carried out according to the principles of  primary and secondary surveys, identifying major life-threa tening injuries of  the airway , respiratory system 

(c)
Figure 8.26
(a)
The plain
/f_i
lms of this 13-year-old are close to normal. On
close inspection, there is a
/f_i
ne periosteal reaction on the
/f_i
bula.
(b)
The cor
-
onal T1-weighted magnetic resonance image shows little more, but
(c)
the
coronal fast short tau inversion recovery (STIR) images and
(d)
axial T2 fast
spin echo with fat suppression show the oedema in bone as white and the
extensive periosteal
/f_l
uid with soft-tissue in
/f_l
ammation. The diagnosis is acute
osteomyelitis.

consuming assessment of  other injures. At no point should imaging delay the treatment of  immediately life-threatening injuries. As in other settings, the quickest and least invasive examinations should be performed first. A radiologist present in the trauma room at the time of  patient assessment is able to evaluate the radiographs rapidly , relay this information back to the team and guide further imaging, which may include further plain films, CT , ultrasound and MRI.