This document discusses radiological imaging techniques for evaluating upper limb ischemia. It begins by providing background on upper limb ischemia, noting it has varied etiologies including atherosclerosis, arteritis, and trauma. CT angiography is described as the preferred initial imaging technique, providing high-quality images of the entire arterial tree to precisely plan revascularization. Other techniques discussed include Doppler ultrasound, MRI, and invasive angiography. The document then provides several examples of upper limb CT angiography findings, demonstrating various pathologies like thrombosis, aneurysms, occlusions, and fistulas. In summary, the document outlines radiological evaluation and various pathologies of upper limb ischemia visualized on CT angiography.

1. Radiological imaging of upper limb ischemia.
Dr/ ABD ALLAH NAZEER. MD.

2. Introduction:
Upper limb ischemia is an uncommon entity which presents less
commonly as compared to lower limb ischaemia, and has a wide
range of etiology and controversies in preoperative investigations
and management. Less than 2% of patients with upper limb ischaemia
presents with rest pain, gangrene or ulcer. Although upper limb loss
is less as compared to lower limb, it can result in severe functional
impairment and disability if there should be any delay in diagnosis
and treatment.
The single most common etiology is thromboembolic events secondary
to atherosclerosis followed by trauma.
Nevertheless, differential diagnoses such as arteritis, thoracic outlet
obstruction and aneurysms need to be considered.
The signs and symptoms of presentation ranged from nonspecific
slight numbness and weakness to pain, pallor and pulselessness. The
most common combination of presenting complaints was cold,
pulselessness and painful upper limb.

3. Upper extremity occlusive disease is relatively uncommon and
accounts for only 5% of all extremity ischemia. Unlike occlusive
disease in the lower extremities, which is generally atherosclerotic
in origin, the etiology of upper extremity occlusive disease is more
varied and can include atherosclerotic disease, arteritis, connective
tissue disorders, occupational injuries, and Vasospastic diseases.
Etiology
Upper extremity occlusive disease can involve the large and small
arteries of the arm or a combination. Atherosclerosis is the most
common cause of large artery disease and generally involves the
subclavian artery, but disease may extend more distally, especially in
the setting of diabetes. Patient risk factors are similar to those of other
vascular beds. Tobacco use is almost universal. Hypercholesterolemia,
hypertension, diabetes and age are also important risk factors.
Inflammatory diseases (giant cell and Takayasu’s arteritis) can also
involve the large vessels. Small vessel disease due to diabetes can lead
to severe complications such as digital ulceration and gangrene.

4. Raynaud’s disease is a Vasospastic disorder that produces a tri-phasic
colour change in the hands or less commonly the feet, in response to cold or
emotional stimuli. The hallmark of this disorder is pallor, cyanosis and post
ischemic hyperemia of a digit or digits, although all three may not always be
present. The disorder is classified as primary when no identifiable cause is
evident or secondary when it is due to either a more proximal occlusion or
other disease process resulting in digital artery vasospasm . Patients whose
occupations involve the use of vibrational tools or who use their hands as a
hammer (especially the hypothenar eminence) can present with Raynaud’s or
frank digital ischemia from either hand-arm vibration syndrome or
hypothenar hammer syndrome. Occlusive lesions in the arm and hand
secondary to scleroderma, rheumatoid arthritis, systemic lupus and other
autoimmune disorders can lead to severe upper extremity ischemia
manifesting as pain, ulceration and gangrene. Thromboangiitis obliterans
(Buerger’s disease) is an inflammatory disease that can produce pain and
ulceration in the fingers and toes. The patient is usually a young man with
a long history of tobacco use.
Rare causes of upper extremity occlusive disease include iatrogenic injury,
trauma, malignancy and frostbite.

5. Common Conditions Associated with Upper Extremity Ischemia:
• Thromboembolism
• Atheromatous Embolization
• Atherosclerosis
• Connective Tissue Diseases( • Scleroderma, • Rheumatoid Arthritis,
• Sjörgren’s Syndrome, • Systemic Lupus Erythematosus)
• Large Artery Vasculitis( • Takayasu’s Disease, • Giant Cell Arteritis)
• Small Artery Vasculitis(• Thromboangitis Obliterans (Buerger’s
disease).
• Blood Dyscrasias
• Myeloproliferative Disorders
• Thoracic Outlet Syndrome
• Latrogenic Injury
• Occupational Exposure(• Hand-arm Vibration Syndrome,
• Hypothenar Hammer Syndrome).
• Vasospasm( • Raynaud’s Disease, • Cocaine Use, • Amphetamine Use).

6. Acute ischemia in the upper extremity
constitutes 10–15% of all acute extremity ischemia. The etiology
is emboli in 90% of the patients. The reason for this higher rate
compared with the leg is that atherosclerosis is less common in
arm arteries. Emboli have the same origins as in the lower
extremity and usually end up obstructing the brachial artery.
Sometimes plaques or an aneurysm in the subclavian or axillary
arteries is the primary source of emboli. Embolization to the
right arm is more common than to the left due to the vascular
anatomy. For the 10% of patients with atherosclerosis and acute
thrombosis as the main cause for their arm ischemia, the primary
lesions are located in the brachiocephalic trunk or in the
subclavian artery. Such pathologies are usually asymptomatic
due to well-developed collaterals around the shoulder joint until
thrombosis occurs, and they cause either micro- or
macroembolization.

7. Clinical Presentation
Acute arm ischemia is usually apparent on the basis of
the physical examination. The symptoms are often relatively
discreet, especially early after onset. The explanation for this is the
well developed collateral system circumventing the brachial artery
around the elbow, which is the most common site for embolic
obstruction. The "six Ps” – pain, pallor, paresthesia, paralysis,
pulselessness, poikilothermia– are applicable also for acute arm
ischemia, but coldness and color changes are more prominent than
for the legs. Accordingly, the most common findings in the physical
examination are a cold arm with diminished strength and disturbed
hand and finger motor functions. Tingling and numbness are also
frequent. The radial pulse is usually absent but is pounding in the
upper arm proximal to the obstruction. Gangrene and rest pain
appear only when the obstruction is distal to the elbow and affects
both of the paired arteries in a finger or in the lower arm. Ischemic
signs or symptoms suggesting acute digital artery occlusion in
only one or two fingers, imply microembolization.

8. Chronic symptomatic ischemia in the upper extremity
is the result of blood flow that is nutritionally inadequate to fulfill
metabolic requirements. Symptoms may also result from
inappropriate thermoregulatory function. Ischemia may be
secondary to inappropriate vessel response when vessels are unable
to vasodilate in response to stress or inappropriate vasoconstriction
(i.e., vasospastic disease); intima/media injury resulting in
aneurysm, embolism, and thrombosis (occlusive disease); or a
combination of both (vaso-occlusive disease). Occlusive events may
occur secondary to low-flow states in vasospastic disease that
precipitate thrombosis development (i.e., secondary occlusion) or
secondary to ischemia from occlusive disease that may produce
autonomic dysfunction and secondary vasospasm. This cross-over
phenomenon creates difficulty in evaluation and management. The
goal of this article is to assess contemporary methods of evaluation,
classification, and management of upper extremity ischemia.

9. Radiological Imaging:
X-Ray to show any evidence of cervical rib.
Duplex ultrasound is rapid, can be performed at the bedside, and has near
100% sensitivity for diagnosing complete arterial occlusion. Ankle-brachial
index (ABI) will be near zero for patients with acute limb ischemia.
CTA has the benefit of rapid availability and high-quality imaging, which
allows for precise planning of revascularization. CTA provides imaging of the
entire arterial tree from the aortic inflow to the digital level. CTA typically
requires 150 mL of iodinated contrast and therefore has to be used with
caution in patients with baseline renal insufficiency (glomerular filtration rate
<40). For patients with renal insufficiency, aggressive hydration before and
after examination with sodium bicarbonate is recommended for CTA or
invasive angiography.
MRA has a limited role in acute limb ischemia, as the examination can be
lengthy (45–60 minutes), is less often available outside regular work hours,
and generally has poorer arterial imaging than 64 (or greater) slice CTA.
Invasive angiography has the advantage of allowing for simultaneous
percutaneous revascularization with both mechanical thrombectomy and
thrombolytic therapy.

12. Acute Upper Limb Ischemia with right
subclavian and brachial thrombus.

13. Upper limb acute ischemia with recent jugular vein thrombosis.

14. With significant external compression with the probe, a visualized
thrombus (blue arrow) is seen within a non-compressible brachial artery

16. The distal (right side subclavian shows no flow.

17. Thrombosis of the brachial artery.

18. Vessels and nerve trauma. Biker’s hammer. (A) Longitudinal and (B) axial colour Doppler
US obtained over the palmar aspect of the hypothenar region. Images show a nearly
complete thrombosis (black arrowheads) of the superficial branch of the ulnar artery.
Some small persistent internal flow signal can be detected (white arrowheads). Note
increase in size of the artery and thickening of its wall. HH=hook of the hamate.

19. Left Cervical rib with upper limb chronic ischemia.

20. CT angiography using modern MDCT scanners has evolved into a highly accurate
noninvasive diagnostic tool for the evaluation of patients with pathologic
abnormalities of the upper extremity arterial system. upper extremity CTA can
effectively evaluate for stenosis, occlusion, aneurysm, or embolic events,
especially when they affect vessels proximal to the wrist.
Atherosclerotic disease affects the upper extremities disproportionately less
than the lower extremities. However, proximal involvement of the upper
extremities is not infrequent. Risk factors are no different than those for other
sites of atherosclerotic involvement and include hypertension, dyslipidemia,
diabetes mellitus, age, and a history of smoking . Claudication is the most
common presenting symptom, though most patients are asymptomatic because
of collateral formation. Blood pressure differences between the upper extremities
can frequently be found in these patients. Symptoms are often chronic, with more
acute symptoms suggesting acute thrombosis or an embolic event. In the setting
of subclavian involvement, upper extremity symptoms may be masked or
overshadowed by symptoms related to compromised flow to the ipsilateral
vertebral artery due to subclavian steal, particularly syncope and presyncope. In
patients with left or right internal mammary bypass grafts, subclavian artery
disease can cause myocardial ischemia. Atherosclerotic disease, when identified
on imaging, should prompt inquiry into concomitant sites of involvement
processes—namely, cardiovascular and cerebrovascular involvement.

21. CT Angiography of the Upper Extremity Arterial System:
Axial subvolume maximum intensity
projection better outlines stenosis
(arrowheads). Axillofemoral bypass
(asterisk) is depicted end-on.
Volume-rendered image shows
axillofemoral bypass graft (arrow) with
stenosis proximal and distal to anastomosis
in native left axillary artery (arrowheads).

22. Volume-rendered CT angiography shows long occlusion of
brachial artery, which was caused by acute thromboembolism.

23. Old woman with acute type A thoracic aortic dissection who presented with acute
chest pain and syncope. Physical examination revealed weak right upper extremity
pulse. CT angiography of right upper extremity, chest, abdomen, and pelvis was
performed to evaluate for aortic dissection and upper extremity arterial pathology.
Oblique multiplanar reconstruction image reveals ascending aortic dissection, with
intimal flap (arrowheads) covering origins of all supraaortic branch vessels.

24. 49-year-old man in chronic phase of Takayasu
disease involving arch and supraaortic
vessels. A, Volume-rendered image shows
right subclavian artery aneurysm (arrow) and
left subclavian artery stent (arrowhead)
implanted for steno-occlusive disease.
49-year-old man in chronic phase of
Takayasu disease involving arch and
supraaortic vessels. B, Axial image shows
concentric thickening (arrowheads) of wall
of origins of all three supraaortic branches.

25. 64-year-old woman with giant cell arteritis who presented with fever,
malaise, and bilateral upper extremity weakness. CT angiography using
axial curved multiplanar reconstruction algorithm shows typical irregular
wall thickening (arrowheads) of bilateral axillary and subclavian arteries.

26. 29-year-old male heavy
smoker with thromboangiitis
obliterans who presented with
ischemic symptoms of both
upper and lower extremities.
A, Upper extremity CT
angiography (CTA) shows
distal ulnar artery occlusion
(short thick arrow) and distal
radial artery contour
irregularity (arrowheads) in
right upper extremity. Note
typical corkscrew collaterals
(long thin arrow).
Stenoocclusive disease was
also present in left ulnar and
interosseous arteries.

27. 50-year-old woman with
history of embolic disease
to left arm and
fibromuscular dysplasia
involving bilateral carotid,
renal, and external iliac
arteries (not shown) who
also had involvement of
left brachial artery with
medial fibrosis, which
shows typical “string-of-
beads” sign (arrowheads).

28. 17-year-old girl with thoracic
outlet syndrome who was
evaluated at outside institution
for embolic event to left hand.
She was found to have
aneurysm of left subclavian
artery, which was subsequently
treated with covered stent.
Several months after
procedure, patient presented
to our institution with
heaviness and coolness of left
arm and hand. A, Volume-
rendered image shows
subclavian artery stent, with
proximal occlusion
(arrowhead) and presence of
left cervical rib (single
asterisk). First rib is marked
with double asterisks. Clavicle
was excluded for clarity.

29. 17-year-old girl with thoracic outlet syndrome who was evaluated at outside institution for
embolic event to left hand. She was found to have aneurysm of left subclavian artery, which was
subsequently treated with covered stent. Several months after procedure, patient presented to
our institution with heaviness and coolness of left arm and hand. B, Curved multiplanar
reconstruction of left subclavian artery shows completely thrombosed stent (asterisks). Patient
underwent subclavian artery vein graft placement and resection of left cervical and first ribs.
Volume-rendered image shows vein graft (asterisks) and resection of left cervical and first ribs.
Curved multiplanar reconstruction confirms vein graft patency (asterisks).

30. 23-year-old man with arteriovenous malformation in right axilla. B, Maximum
intensity projection of upper extremity CT angiography shows malformation
(arrowhead), with lateral thoracic artery as main feeder, and early venous
drainage, Volume-rendered image shows arteriovenous malformation and
anomalous high origin of radial artery (arrowhead), which is normal variant.

31. 17-year-old boy with known diagnosis of Ehlers-Danlos syndrome type 4 who presented
to emergency department with extremely painful acute onset swelling of right axilla
and Pulseless right upper extremity. A, CT of chest and upper extremity was performed.
Unenhanced CT shows large right axillary hematoma (asterisk). B, Maximum intensity
projection CT angiography shows extravasation from spontaneously ruptured right
axillary artery (arrow). Emergent proximal surgical ligation was performed.

32. Angiogram of the right-
upper extremity. (A)
Axillary artery occlusion
caused by a distal
segment. (B) The injured
artery and the extensive
collateralization.

33. 23-year-old man with dialysis fistula who presented with reduced flows while undergoing
hemodialysis and ischemic symptoms in fingers of left hand. B, Subvolume maximum
intensity projection (MIP) shows patent arterial anastomosis but diseased radial artery (A)
with occlusion distally (arrowheads). There was also stenosis in vein (V) immediately distal
to anastomosis (arrow). A, Upper extremity CT angiography volume-rendered view shows
dialysis fistula with aneurysm formation (asterisk) on venous side.

34. 23-year-old man with dialysis fistula who presented with reduced flows while
undergoing hemodialysis and ischemic symptoms in fingers of left hand. More
central subvolume MIP shows critical stenosis of left subclavian vein (arrow).

35. 59-year-old woman who underwent stent placement in left subclavian artery at outside
institution presented with recurrent left upper extremity claudication. CT angiography
shows stent fracture (arrow) and severe stenosis (arrowheads) due to intimal hyperplasia.

36. Completion angiogram of the right upper limb revealing the axillary–
brachial–ulnar axis and the partially-thrombosed aberrant radial artery.

37. Chest roentgenogram demonstrates
the clavicular abnormality.
Arch aortogram demonstrates a filling
defect in the right subclavian artery and
occlusion of the axillary artery.

38. Venogram shows occlusion of the right
subclavian vein extending to the first
rib, with multiple collateral vessels.
An angiogram in a 35-year-old woman with
right arm ischemia that demonstrates right
subclavian artery occlusion from the medial
margin of the first rib to the axillary artery at
the level of the humeral head.

39. An arteriogram of the right shoulder
in neutral position, demonstrating
right subclavian stenosis (arrow).
An arteriogram of the right upper extremity in
abduction, demonstrating increased subclavian
artery stenosis and aneurysmal dilation (arrow)
in the location of the clavicle and first rib.

40. Thoracic outlet syndrome with stenosis of the left subclavian vein.

41. 73-year-old woman
with acute embolus
in left axillary artery .

42. Left axillary artery occlusion in a patient with Wegener's granulomatosis .

43. Left brachial artery thrombosis in a patient with Wegener's granulomatosis .

44. Angiogram of upper extremity. The top is in a normal position. The bottom
is in a hyperabducted position (arrow indicates area of stenosis).

45. Distal axillo-brachial artery occlusion.

46. Septic embolization from severe prosthetic aortic valve endocarditis
resulted in a 2.5cm brachial artery pseudoaneurysm (circled) that
was associated with a pocket of purulence and upper limb ischemia.

48. Angiogram that demonstrates blockage of the ulnar artery.

49. Axial CT angiography source image shows ulnar artery thrombosis with ulnar artery
aneurysm (between arrowheads). Ulnar artery reconstruction with right leg saphenous
vein autograft was performed, and patient became symptom free. Volume-rendered
reconstruction shows occluded ulnar artery (between arrowheads) at Guyon canal.

50. Angiogram of end-stage Raynaud’s disease
with extremely poor peripheral circulation.
Angiogram that demonstrates
an ulnar artery aneurysm.

51. An angiogram demonstrating lack of blood flow to vessels
of the hand in Buerger's disease with ischemia to the fingers.

52. Angiogram of a patient with Buerger’s disease that
shows decreased circulation of index and thumb.
Angiogram that shows decreased
circulation in the ulnar digits of the hand.

53. Angiogram of right upper extremity with "string of beads" appearance of the
brachial artery (lower left) in fibromuscular dysplasia with chronic ischemia.

54. Conclusions.
Upper limb ischaemia remains infrequently seen
compared to lower limb ischaemia. Nevertheless,
the complications and late effects can result in
significant impairment in function.
Evaluation of upper limb ischaemia requires
careful history taking and clinical examinations.
Although angiography remains the gold standard,
other non-invasive tools such as duplex US.
Prompt surgical intervention results in favorable
outcomes.

55. Thank You.