Clinical presentation CHD is broadly divided into 2 groups: \200 Acyanotic lesions, which include left-to-right shunts such as atrial septal defect (ASD), VSD, PDA, and left-sided valvular diseases such as congenital MS and A S. Cyanotic lesions, which are typically right-to-left shunts such as tetralogy of Fallot or complex lesions leading to admixture of oxygenated and de-oxygenated blood such as total anomalous pulmonary venous drainage (TAPVD), truncus arteriosus, and s ingle ventricle states. Acyanotic lesions commonly present with failure to thrive, recurrent res- piratory infectio ns, \200\230attacks of asthma \200\231, and heart failure. If undetected they progress to pulmonary hypertension which may result in shunt reversal and the development of cyanosis ( Eisenmengerization). Cyanotic heart diseases typically present with cyanotic spells and failure to thrive. Those due to admixture lesions will often present with heart failure as well. Patients may have associated syndromes and congenital anomalies affecting other organs and systems. Imaging Plain \201 lm (Fig. The CXR will not make a speci \201 c anatomical diagnosis, b ut combined with an appropriate history will allow broad categorization of disease and guid e more specialized investigation. 7.12 ) Pulmonary plethora (increased vascular markings seen all the way to the periphery of the \201 lm) is seen in acyanotic heart disease. With progression of disease the lungs become d arker and \200\230pruning \200\231 of the vessels is seen. Echocardiography \200 This is the mainstay of imaging for congenital heart disease. \200 Outlines the anatomical abnormality and secondary changes such as chamber enlargement, wall hypertrophy, and cardiac function. Cardiac catheterization Using a peripheral (usually femoral) venous or arterial approach, a llows assessment of cardiac anatomy, ventricular function, ventricular and pulmonary artery pressures. Cardiac CT \200 Has a limited but evolving role. \200 May be used in patients with pace makers or other metallic devices which preclude MRI. SUBASH KC/NMC-15TH/2014 CONGENITAL HEART DISEASE 117 Provides useful anatomical detail but little functional information compared with echo or MRI. Advantages of CT over MRI include the demonstration of associated lung abnormality, speed of acquisition, and high spatial resolution. Cardiac MRI \200 Has an ever-expanding role, allowing assessment of: Intra- and extracardiac anatomy. \200 Valvular function and pressure gradients. \200 Ve ntricular function and volumes. The lack of ionizing radiation is another advantage over CT in this group of patients, who are often young children needing follow-up imaging over a long perio d of time. Information for the radiologist \200 The suspected abnormality, echo results, exact infor mation sought, and detail regarding previous intervention and surgery. It is important to know about pacemakers and metallic devices that preclude an MRI examination. Fig. 7.12 pulmonary arteries, cardiomegaly, and plethoric lungs. Note also how the aortic a rch appears smaller than usual. Echo con \201 rmed a large ASD. CXR of an 18-year-old woman reveals marked enlargement of the SUBASH KC/NMC-15TH/2014 118 CHAPTER 7 Vascular conditions Ischaemic heart disease A range of cardiac abnormalities caused by insuf \201 cient blood supply reaching the myocardial muscle mass, usually secondary to atherosclerotic narrowing of the coronary arteries. Associated with smoking, hyperten- sion, diabetes, family history , hypercholesterolaemia. Clinical presentation May manifest acutely with severe central chest pain and breathlessnes s, either acute MI or unstable angina. May have a more protracted course with occasional chest pain (angina) especially stress or exercise related, heart failure, ischaemic CM or cardiac arrhythmias. Imaging Plain \201 lm \200 Chest radiographs may be completely normal. \200 Cardiomeg aly with left ventricular enlargement is often seen. \200 Occasionally myocardial calci \201 cation due to a previous transmural infarct and calci \201 ed ventricular aneurysm may be apparent. May be signs of heart failure in the lung and pleural effusions. Echocardiogram Provides useful diagnostic and prognostic information including: \200 Regi onal wall motion abnormalities. \200 Chamber hypertrophy and enlargement. \200 Identi \201 cation of ventricular aneurysm and associated thrombus. \200 EF. It is valuable in follow-up after both medical treatment and percutaneous or surgical inter vention. Coronary angiography (Fig. 7.13) Provides details of signi \201 cant stenoses and occlusio ns in the coronary arteries and helps plan further percutaneous or surgical intervention. Radionuclide perfusion studies \200 Limited use in the acute setting but proven role in e valuating ischaemic damage to the heart and excluding ischaemia as a cause of non speci \201 c chest pain. Stress and rest Tl-201 and Tc99 m (MIBI scan) provides re-distribution information thus helping to identify viable but ischaemic muscle. MUGA scan using Tc-99 m labeled red blood cells can evaluate wall motion and EF. Cardiac CT \200 Calcium-scoring identi \201 es the burden of coronary artery disease by looking at the calcium load in the coronary arteries and is useful in patients where the ca use of chest pain is not established. CT coronary angiogram with contrast is not yet established as the modality of choice for im aging the coronaries prior to intervention but repeated studies show a high negative predic tive value \200\224 i.e. is useful in excluding coronary artery disease. SUBASH KC/NMC-15TH/2014 ISCHAEMIC HEART DISEASE 119 ECG-gated MRI \200 MRI has a tremendous potential in the imaging of ischaemic heart disease. Cine MRI is an accurate method of assessing cardiac function. \200 Gadolinium-enhanced MR I can help identify areas of ischaemia, predict myocardial viability, and delineate areas of subendocardial infarction. Information for the radiologist \200 Duration of symptoms. \200 Associated illnesses. \200 Smoking history, medical history. \200 ECG \201 ndings including cardiac rhythm. (a) (b) Fig. 7.13 stenosis in the right coronary artery. (b) Same patient following endovascular st enting of the stenosis, which resulted in maintained symptom relief. (a) Coronary angiogram of a man with severe angina reveals a signi \201 cant SUBASH KC/NMC-15TH/2014 120 CHAPTER 7 Vascular conditions Cardiac tumors Cardiac tumors may be primary or secondary. Metastatic disease from an extra cardiac tumor is the most common cause of an intracardiac mass. Lung and breast are the mo st common primary sites. Primary cardiac tumors are rare and more often benign than malignant. Some of the more common primary tumors include: \200 Myxoma: the most common primary card iac tumor, and benign (Fig. 7.14 ). Usually occurs in left atrium, often arising from a \200\230stalk-like \200 \231 pedicle. Lipoma. \200 Rhabdomyoma: most common primary tumor in pediatric group, associated with tuberous sclerosis. Sarcoma: the most common primary malignant cardiac tumor is angiosarcoma but there are many other types of sarcoma. Clinical presentation Present at any age with palpitations, shortness of breath, cough, che st pain, or syncope. Clinically there may be a heart murmur, arrhythmia, or evidence of car diac failure. May present with complications such as pulmonary emboli or endocarditis. Imaging Plain \201 lm Rarely able to detect the tumor but may reveal cardiomegaly, left a trial enlargement, calci \201 cation, or pulmonary oedema. Ultrasound (echocardiogram) Usually the initial specialist investigation, offers real-time imaging of the tumor throughout the cardiac cycle and good anatomical detail. Provides info rmation on cardiac and valvular function. CT Sensitive but often unable to characterize the mass. Modern \200\230ECG-gated \200\231 techniques provide excellent anatomical information. More commonly used to look for a prima ry tumor elsewhere if the cardiac mass is thought to be a metastasis. MRI More sensitive than echocardiography and unlike CT is radiation free. However, does req uire prolonged breath-holding which can be dif \201 cult for some patients. Depicts cardia c anatomy, ventricular and valvular func- tion, and offers more information regarding tissu e characteristics than CT. Nuclear medicine MIBG (metaiodobenzylguanidine) scans can detect phaeochromocytoma with hig h sensitivity. PET may be useful if metastatic disease is suspected. Information for the radiologist \200 History of malignancy. \200 Concern for complicati ons, e.g. heart failure, valvular disease, PE. \200 Heart and respiratory rate/rhythm \200 Echocardiogram \201 ndings. \200\224 affect suitability for MRI/CT. SUBASH KC/NMC-15TH/2014 CARDIAC tumors 121 Fig. 7.14 to the wall of the left atrium. Surgery con \201 rmed a left atrial myxoma. Axial image from a cardiac MRI study revealing a soft tissue mass adherent SUBASH KC/NMC-15TH/2014 122 CHAPTER 7 Vascular conditions Abdominal aortic aneurysm De \201 ned as widening of the aortic caliber to caliber of an a djacent normal segment. > 3cm, or at least 1.5 times the Clinical presentation Clinical presentation varies widely. Often they are picked up inciden tally on imaging such as an abdominal ultrasound. Occasionally, they present with symptoms such as pain or a palpable, pulsatile mass. Rarely, they can present as an acute emergency following active leak or rupture. Up to 80 % of aneurysms are fusiform with circumferential involvement. The remainder are saccular. True aneurysms involve all 3 layers of the wall, whilst pseudo- aneurysms (usually seen following trauma or previous limited dissection) are due to partial disruption of the aortic wall with the escaping blood limited by adventitia. Aneurysms of the descending thoracic and abdominal aorta are usually the result of atherosclerosis. Although most common in the infra-renal aorta, various segme nts can be involved and occasionally extensive thoracoabdominal aneurysms may be seen. Imaging Plain \201 lm The outline of a calci \201 ed aneurysm can be appreciated on the abdominal radiograph. In case of leaking aneurysms, obscuration of the psoas shadow may be seen. Ultrasound Abdominal ultrasound is the mainstay of aneurysm surveillance allowing accurate measurements of the aortic dimension (Fig. with abdominal aortic aneurysm will have yearly ultrasound to look for increasing aneurysm size, which may eventually necessitate surgical repair. 7.15 ). Most patients CT angiogram Multislice CT scanning is the investigation of choice if intervention is requi red, either surgical or radiological. Arterial phase imaging shows the exact extent of the aneurysm, branch involvement and identi \201 es cases suitable for endovascular therapy (E VAR) (Fig. 7.16 ). CTA is also used in the follow-up of EVAR to identify any post- procedural stent related complication. When patients present acutely with suspected bleeding or leakage, urgent CT to con \201 rm the diagnosis and plan best treatment is appropriate. Contrast-enhanced MRI There is a limited role for contrast-enhanced MRI in those patients w here radiation exposure is a major issue or others with iodine allergy which precludes the use of CT contrast. Information for the radiologist Any previous imaging and documented measurements of the ane urysm and the treatment plan (surgery versus endovascular). SUBASH KC/NMC-15TH/2014 ABDOMINAL AORTIC ANEURYSM 123 Fig. 7.15 Note how the thick layer of intramural thrombus is differentiated from the echo f ree vessel lumen. Abdominal ultrasound image revealing a 5.6cm aneurysm of the aorta. Fig. 7.16 hemorrhage into the aneurysm wall and leak into the retroperitoneum. The patient went straight from CT to have an endovascular stent. CT scan from a different patient revealing a large aneurysm with signs of SUBASH KC/NMC-15TH/2014 124 CHAPTER 7 Vascular conditions Peripheral vascular disease: diagnosis A group of diseases of different aetiologies, affect ing the arteries of the upper and lower extremities. Atherosclerosis is the predominant cau se. Diabetes mellitus, hypertension, hypercholesterolaemia, smoking and age are major risk factors. Other causes include Buerger \200\231s disease, in \202 amma- tory and autoimmune arteritis, Raynaud \200\231s disease, and thromboembolism. Clinical presentation \200 Claudication is the hallmark of early peripheral vascular dise ase (PVD). It is a cramping muscular pain due that develops on exertion and is relieved by rest. Progression of disease leads to rest pain, non-healing ulcers, and occasionally gangrene. Patients with acute thromboembolism present with a painful white leg. \200 Along with the clinical presentation, ankle \200\223brachial pressure index (ABPI) (the ratio of the systolic pressure at the ankle to that in the arm) is used for ris k strati \201 cation of patients with PVD. Imaging Plain \201 lm This is of limited value in PVD. However, due to the common risk fa ctors almost all patients should have a plain chest radiograph. Ultrasound and Doppler evaluation \200 This is a vital initial assessment tool of the per ipheral vascular anatomy and identi \201 es the site and severity of stenosis. Provides information of the location, extent, and morphology of the stenotic lesion. Doppler assesses the impact of the lesion on \202 ow, the degree of turbulence created, p ost-stenotic velocity (which indicates the degree of obstruction), and the distal run-off. Ultrasound is also important in the follow-up of patients after treatment to identify those needing early re-intervention. Angiography As CT and MR develop, the role of diagnostic angiography is diminishing. Howeve r, it remains the \200\230gold standard \200\231 for assessing the anatomy and disease bur den and is a part of the assessment prior to endovascular inter- vention (see b Angiography , p. 6). CT angiogram \200 Current multislice CT scanners allow the imaging of the entire peripher al arterial tree without arterial catheterization (needed for angiography). Iodine-based contrast agent injected into a peripheral venous cannula is used to visualize the arteries. Spatial resolution is superior to that of MRI, but there is a signi \201 cant radiation burden. CT is especially useful in heavily calci \201 ed arteries and in the presence of stents. Whilst the images are acquired in the axial plane, modern scanners and computer software al lows the vessels to be displayed in various ways: \200 Multi-planar reformats (MPR) view the vessel along its course. SUBASH KC/NMC-15TH/2014 PERIPHERAL VASCULAR DISEASE: DIAGNOSIS 125 Maximum intensity projection (MIP) picks the brightest pixel in each location and provides an angiogram like picture. Shaded surface display (SSD) utilizes the pixels on the surface. \200 Volume rendering (V R) techniques combine SSD and MIP to provide a 3D image of the region of interest. MR angiogram (Fig. \200 A gadolinium-enhanced MR study of the peripheral vascular tree. \200 The various imaging manipulations such as MPR, MIP, and VR can all be 7.17 ) used as for CTA. The two major advantages of MR over CT are the ability to image in different planes (e.g. a long the length of the vessel) and the absence of any radiation burden. MRA is gradually becoming the investigation of choice in the assessment of PVD prior to intervention/surgery, except in cases where it is either contraindicated or technically limited (stents or heavy calci \201 cation). Information for the radiologist \200 Duration and level of symptoms, e.g. presence of res t pain. \200 Pacemaker? \200 Blood results including INR if arterial puncture being con templated. \200 Any previous imaging and intervention. Fig. 7.17 common iliac artery. Image from an MR angiogram revealing a tight focal stenosis in the right SUBASH KC/NMC-15TH/2014 126 CHAPTER 7 Vascular conditions Peripheral vascular disease: radiological treatments Endovascular intervention has revoluti onized the management of PVD. New balloon catheters and stents provide the interventional r adiologist with a wide armamentarium to tackle various lesions. The basic prin- ciple of en dovascular intervention is the dilatation of a stenosed segment by applying a strong but co ntrolled centrifugal force, which results in stretching and \201 ssuring of the vessel an d in time to remodeling. In speci \201 c instances, a tubular mesh (stent) is used as a sc affold to hold the segment open while remodeling occurs. Indications \200 Worsening claudication. \200 Rest pain. \200 Failed medical treatmen t. \200 Signi \201 cant stenosis (more than a 50 % luminal compromise). Stents are used in larger vessels or when balloon dilatation is either not practical or has failed. Relative contraindications include: The presence of long segment severe stenosis. \200 Multiple severe narrowings affecting a long segment. \200 Occluded segment. \200 Contraindication to contrast (although eithe r CO be used in cases of allergy to iodinated contrast). 2 or gadolinium may Distal small vessel disease, affecting the foot vessels, is not treated endovascularly. Different types of endovascular intervention 1 Balloon angioplasty. 2 Laser angioplasty and cryoplasty. 3 Atherectomy: directional and rotational types. 4 Stents: covered or bare-met al stents, self- and balloon-expandable stents, nitinol stents, drug-eluting stents, stent grafts. Procedure Consent Informed consent should include the risk of access site complications, fa ilure of procedure, vessel dissection, and distal embolization. Access The common femoral artery is most commonly used. Brachial route is occasionally need ed. Local preparation The site is cleaned and local anesthesia administered. Under strict aseps is the appropriate vessel is punctured with a suitable needle. Technique Once the vessel is punctured and a catheter is passed, an angiographic run is per formed to outline the anatomy of the diseased segment and visualize SUBASH KC/NMC-15TH/2014 PERIPHERAL VASCULAR DISEASE: RADIOLOGICAL TREATMENTS 127 the run-off. These images are transferred to an adjacent screen to be used as a road map fo r the intervention. The next stage is to pass a guidewire and a balloon catheter across the stenotic segment. The balloon is connected to a pressure gauge (which helps guide the balloon dilatation) and gradually expanded until maximum dilatation is reached. Following the procedure, a completion angiogram is performed to assess the outcome and also the run-off (Fig. 7.18 ). The principles of stent dilatation are essentially the same. Stents may either be balloon-expandable or self-expandable. Complications \200 Puncture site complications: haematoma, pseudo-aneurysm, dissection, AV \201 stula, and infection. Contrast allergy and anaphylaxis. \200 Stent migration, balloon and stent rupture. \200 Distal embolization. Information for the radiologist \200 Renal function. \200 Clotting pro \201 le. \200 Prior imaging. \200 Any major underlying morbidity. (a) (b) Fig. 7.18 and a metal stent placed across the iliac artery stenosis. b) Catheter angiograph y post-stent deployment con \201 rms good \202 ow of contrast into the peripheral vessel s of both legs. a) Same patient as in Fig. 7.17 . Catheter angiography has been performed SUBASH KC/NMC-15TH/2014 128 CHAPTER 7 Vascular conditions IVC \201 lter insertion Pulmonary embolism (PE) is a common and sometimes fatal complicat ion of deep vein thrombosis (DVT). By insertion of a \201 lter into the IVC, a mechanical obstacle is created in the path of any thrombus traveling up the IVC toward the heart. Indications An IVC \201 lter may be permanent or retrievable, depending on the reason for insertion. Whilst controversy exists about the relative indications for \201 lter insert ion, their use is widely accepted in the following situations: \200 DVT/PE in patients wi th a contraindication to anticoagulation such as a recent major intracranial bleed. Progression of venous thromboembolism despite adequate anticoagulation. In selected situations, they may be inserted prophylactically. \200 Floating iliac thromb us. \200 Patients with major trauma and DVT. \200 Patients with DVT who are to undergo major surgery. \200 PE/DVT in pregnancy. Procedure Consent Written informed consent including failure of deployment, migration of th e \201 lter, and thrombus forming on the device. Access Usually performed from a jugular or femoral approach. Inferior venacavogram Catheter in the low IVC and a \202 ush injection to evaluate the IV C for clots and identify the renal vein origins. Deployment The \201 lter is optimally deployed in the infrarenal IVC (Fig. 7.19 ), althou gh on occasion they can be deployed above the renal veins. Complications \200 Related to the puncture site: bleeding, haematoma. \200 Related to t he \201 lter: migration of the \201 lter into the heart, tilted \201 lter (may need d eployment of another \201 lter), \201 lter thrombosis (potentially life threatening and may warrant removal). Information for the radiologist \200 Previous imaging. \200 Infection status. \200 Cl otting status is vital before proceeding with the \201 lter insertion. \200 Clinical ba ckground and indication. SUBASH KC/NMC-15TH/2014 IVC FILTER INSERTION 129 Fig. 7.19 the device in the IVC, below the level of the renal veins. Note the small hook on its top end to help with retrieval should that be appropriate. Image acquired after deployment of an IVC \201 lter con \201 rms the position of SUBASH KC/NMC-15TH/2014 130 CHAPTER 7 Vascular conditions Arteriovenous \201 stula A connection between an artery and an adjacent vein which result s in shunting of blood to the venous side bypassing the distal segment. Etiology \200 Congenital: visceral or peripheral vascular. \200 Syndromic: Osler \200 \223Rendu \200\223Weber syndrome. \200 Post-traumatic. \200 Pathological processes such as infection or malignancy resulting in erosion of vessels and development of abnormal connections. \200 Iatrogenic: following fe moral punctures, visceral biopsies. \200 Therapeutic: arteriovenous \201 stula (AVF) cr eated surgically for haemodialysis. Clinical presentation \200 They are often asymptomatic. \200 High- \202 ow shunting ca n lead to high-output heart failure. \200 A palpable thrill with an associated continuous murmur is the clinical hallmark of a peripheral \201 stula. Compression of peripheral AVF may result in bradycardia (Branham \200\231s sign). Local gigantism and vascular insuf \201 ciency distal to the \201 stulous connection are known sequelae. In the viscera, shunting can lead to distal infarcts and AVF in the lung can cause paradoxical embolism CVA. \200\224 these patients may present with Peripheral AVF, including those created for haemodialysis, result in arterialization of the veins (dilated, prominent, and tortuous). Imaging Plain \201 lm Limited role, but pulmonary AV \201 stulae can have typical appea rances \200\224a pulmonary nodule with prominent feeding artery and draining veins. Ultrasound and Doppler \200 Peripheral and some visceral (e.g. renal) AVF are diagnosed o n ultrasound/Doppler assessment. Color Doppler demonstrates turbulence at the site of \201 stula. \200 Pulsed Doppler ad ds information by demonstrating focal low resistance arterial \202 ow with continuous forward \202 ow throughout the cardiac cycle. It will also demonstrate the arterialized (pulsatile) trace of the venous waveform. Ultrasound is invaluable in assessing surgical AVF in patients on dialysis for early detect ion of complications such as stenosis, thrombosis, and occlusion. Venography (prior to formation of AVF) Upper limb venography is essential to demonstrate th e venous anatomy prior to formation of an AVF. SUBASH KC/NMC-15TH/2014 ARTERIOVENOUS FISTULA 131 This is performed by segment-wise injection of the veins and imaging the forearm, arm, and proximal veins one after the other. For the proximal intrathoracic veins, simultanous injec tion from both sides is required. Radionuclide imaging Some visceral AVF (such as pulmonary and hepatic) can be assessed usin g Tc-99 m labeled sulfur colloid or macroaggregated albumin. This is occa- sionally require d when clinical and Doppler assessments are equivocal about the degree of shunting. CT and MR Both CT and MRA can be used to identifying visceral AVF and their asso- ciated se quelae and complications (Fig. AVMs in the lung. 7.20 ). HRCT is used to diagnose Information for the radiologist \200 Any previous \201 stulae that have been created an d subsequent complications or intervention should be conveyed when requesting a Doppler examination or v enography. Clinical signs. \200 Blood results, including O 2 saturations if large shunts are suspected. Fig. 7.20 Angiogram of a surgically created AVF for dialysis in a patient with renal failur e. Note the wire crossing between the artery and vein which has been used to stretch a sten osis of the \201 stula. SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014 133 Chapter 8 Neurology differential diagnosis Intracerebral \200\230mass \200\231 134 Intracranial calci \201 cation Multiple-ring enha ncing lesions 134 Cerebellopontine angle mass 135 134 SUBASH KC/NMC-15TH/2014 134 CHAPTER 8 Neurology differential diagnosis Intracerebral \200\230mass \200\231 \200 Primary brain tumor, e.g. glioblastoma multifor me. \200 Metastasis. \200 Arterial infarct. \200 Abscess. \200 Demyelination. \200 Haematoma. \200 Encephalitis. \200 Aneurysm. Intracranial calci \201 cation \200 Normal structures: \200 Pineal gland. \200 Choro id plexus. \200 Dura. \200 Basal ganglia. \200 Arachnoid granulations. Vascular: Atherosclerosis. \200 Aneurysms. \200 AVM. \200 Old infarct/hemorrhage. Tumors: Commonly meningioma. Infections: \200 e.g. TB. Basal ganglia calci \201 cation: Normal. \200 Endocrine. \200 Metabolic. \200 Infection. \200 Toxic. Neurocutaneous syndromes: \200 Sturge \200\223Weber syndrome. \200 Tuberous sclerosis. \200 Neuro \201 bromatosis. Multiple-ring enhancing lesions \200 Metastases. \200 Abscesses. \200 Lymphoma. \200 Demyelination. \200 Multifocal glioma. \200 Multiple infarcts. \200 Contusions/haem atomas. SUBASH KC/NMC-15TH/2014 CEREBELLOPONTINE ANGLE MASS 135 Cerebellopontine angle mass \200 Acoustic neuroma. \200 Meningioma. \200 Epidermoid. \200 Aneurysm. \200 Metastasis. SUBASH KC/NMC-15TH/2014 This page intentionally left blank SUBASH KC/NMC-15TH/2014