Duplex ultrasonography, magnetic resonance angiography, and computed tomography angiography for diagnosis and assessment of symptomatic, lower limb peripheral arterial disease: systematic review
BMJ 2007; 334 doi: https://doi.org/10.1136/bmj.39217.473275.55 (Published 14 June 2007) Cite this as: BMJ 2007;334:1257All rapid responses
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Further to my previous rapid response, I have unearthed my old copy
of Hamilton Bailey's "Demonstration of physical signs in clinical surgery"
(15th Ed 1973). This clearly describes Fuchsig's sign (or the crossed leg
test) on page 390, so Rehman is some 30+ years too late to claim the sign
as his own!
Paul Fuchsig was then Professor of Surgery at Vienna University.
Competing interests:
None declared
Competing interests: No competing interests
Lack of clinical experts leeds to reductions of practical values of evidence—based medicine reports.
I congratulate the authors on their HTA-report [1] on diagnosis and
assessment of symptomatic lower limb peripheral arterial disease which was
published recently in BMJ [2]. The authors could show that the different
imaging technologies vary in their diagnostic accuracy compared to the
reference standard of conventional angiography. In my opinion as a
radiologist there is, however, an important detail missing in the BMJ
publication as well as in the HTA-report. Diagnostic accuracy in imaging
studies strongly depends on technical parameters such as spatial and
contrast resolution. In MRI a main factor for image quality is the signal-
to-
noise-ratio (SNR), which is influenced by several parameters, such as
field
strength, Matrix, Field-of-View (FOV), slice thickness, receive bandwith,
repetition time (TR), echo time (TE) [3-5]. In spiral- or multidetector
computed tomography (MDCT) pixel noise, slice sensitivity profiles and
resolution in the z-axis are essential parameters, which are influenced by
collimation, table feed (pitch), reconstruction algorithms, number of
detector
rows, tube current and voltage [6]. These parameters are essential to rate
the
results of a radiological study.
I guess the authors should have involved a clinical (radiological)
expert in
their work. To consider the technical parameters in the evaluation would
have
strongly improved the clinical value of the paper, and its results would
be
more valuable for the daily work process. Excluding information important
to
clinicians reduces the value and impact of such reviews and is not in the
spirit
of evidence-based practice.
References
1. Collins R, Cranny G, Burch J, Aguiar-Ibanez R, Craig D, Wright K,
et al. A
systematic review of duplex ultrasound, magnetic resonance angiography and
computed tomography angiography for the diagnosis and assessment of
symptomatic, lower limb peripheral arterial disease. Health Technol Assess
2007;11(20):1-202.
2. Collins R, Burch J, Cranny G, Aguiar-Ibanez R, Craig D, Wright K,
et al.
Duplex ultrasonography, magnetic resonance angiography, and computed
tomography angiography for diagnosis and assessment of symptomatic,
lower limb peripheral arterial disease: systematic review. BMJ
2007;334(7606):1257.
3. Bushberg JT. The Essential physics of medical imaging. Baltimore:
Williams
& Wilkins, 1994.
4. Mitchell DG. MRI principles. Philadelphia: Saunders, 1999.
5. Westbrook C, Kaut-Roth C. MRI in practice. Oxford; Boston:
Blackwell
Scientific Publications, 1993.
6. Kalender W. Computed tomography: fundamentals, system technology,
image quality, applications. Munich: MCD Verlag, 2000.
Competing interests:
None declared
Competing interests: No competing interests
Habib u Rehman describes a bedside test to show popliteal artery
pulsation.
We medical students at Oxford were taught this technique in the
1970s, so it's certainly not new. It had an eponymous title - I think
"Fuchsig's sign", but my memory may be letting me down here!
Competing interests:
None declared
Competing interests: No competing interests
Editor,
Collins et al and the accompanying editorial to their systematic
review conclude that contrast-enhanced magnetic resonance angiography
(MRA) is a viable alternative to conventional contrast angiography for
assessing patients with peripheral arterial disease before treatment
[1,2]. The authors found an adverse event rate of up to 10% associated
with contrast-enhanced MRA, lower than other techniques and generally mild
compared to conventional contrast angiography.
Their systematic review used data from studies published over the
period up to April 2005. We agree with their conclusions although feel it
is important to draw attention to data first published in January 2006
regarding the association between the use of gadolinium-based contrast
agents for MRA and the development of nephrogenic systemic fibrosis (NSF)
[3].
NSF is a newly described chronic, debilitating disease characterised
by progressive fibrosis of the skin, heart, lungs and pleura with
considerable morbidity and mortality. Development is predominately
restricted to patients with stage V CKD (estimated glomerular filtration
rate of less than 15ml/min) and in those with acute renal failure
especially in the context of hepatic failure. The majority of cases have
been associated with the use of gadodiamide (Omniscan), some with
gadopentate dimeglumine (Magnevist) and a few with gadoversetamide
(Optimark) – all linear gadolinium chelates.
Our local study of patients on renal replacement therapy in Glasgow
[4] found a diagnosis of NSF in 3.1% of those exposed to gadodiamide, a
similar finding to those described by other groups [5]. A dose-dependent
relationship was found.
Many patients with peripheral vascular disease will have concurrent
kidney disease and it is important that the small yet significant risk of
developing NSF be considered when deciding whether to proceed with
contrast-enhanced MRA in patients with advanced kidney disease.
Peter C. Thomson Research Fellow in Nephrology, Renal Unit, Glasgow
Royal Infirmary, Glasgow G4 0SF. peter.thomson@northglasgow.scot.nhs.uk
Tara A. Collidge Specialist Registrar, Renal Unit, Glasgow Royal
Infirmary
Patrick B. Mark Specialist Registrar, Renal Unit, Western Infirmary,
Glasgow
Jamie P. Traynor Specialist Registrar, Renal Unit, Western Infirmary,
Glasgow
Keith Simpson Consultant Nephrologist, Renal Unit, Glasgow Royal
Infirmary
Alan G. Jardine Professor of Nephrology, Renal Unit, Western
Infirmary, Glasgow
Scott T. Morris Consultant Nephrologist, Renal Unit, Glasgow Royal
Infirmary
Giles H. Roditi Consultant Radiologist, Dept of Radiology, Glasgow
Royal Infirmary
Competing Interests: None declared
1. Collins R., Burch J., Aguiar-Ibanez R. et al. Duplex
ultrasonography, magnetic resonance angiography, and computed tomography
angiography for diagnosis and assessment of symptomatic, lower limb
peripheral arterial disease: systematic review. BMJ 2007; 334(7606):
1257.
2. Bradbury A.W., Adam D.J. Diagnosis of peripheral arterial disease of
the lower limb. BMJ 2007; 334(7606): 1229.
3. Grobner T., Gadolinium--a specific trigger for the development of
nephrogenic fibrosing dermopathy and nephrogenic systemic fibrosis?
Nephrol Dial Transplant 2006; 21(4): 1104-8.
4. Collidge T.A., Thomson P.C., Mark P.B. et al. Gadolinium-enhanced
magnetic resonance imaging and nephrogenic systemic fibrosis – a
retrospective study of a renal replacement therapy cohort. Radiology 2007
(in press).
5. Broome D.R., Girguis M.S., Baron P. et al. Gadodiamide-associated
nephrogenic systemic fibrosis: why radiologists should be concerned. Am J
Roentgenol 2007; 188: 586-592.
Competing interests:
None declared
Competing interests: No competing interests
Editor
The systematic review by Collins et al for assessment of symptomatic
peripheral arterial disease (PAD) is welcome . An important question,
however, is to decide when to investigate patients for PAD. Significant
proportions of patients do not have classical features of intermittent
claudication and therefore PAD is an under-diagnosed condition . Clinical
examination is an important part of the evaluation in deciding which
patients should undergo further assessment and palpation of the peripheral
pulses is an important component of the clinical examination. Any palpable
pulse abnormality (absent or educed femoral, popliteal, dorsalis pedis, or
posterior tibial arteries) increases the likelihood of PAD (LR, 4.70, 95%
CI, 2.20-9.90) and the absence of any palpable pulse abnormality decreases
the likelihood of PAD (LR. 0.38; 95% CI, 0.23-0.64) . However, assessing
patency of the popliteal artery is not always possible by palpation. This
is due to a combination of deep placement of the artery in the popliteal
fossa and the presence of considerable quantity of fat both behind the
artery and in the superficial tissues. A study by Brearley et al showed
that surgical trainees and non-vascular surgeons fail to detect 23% of
palpable popliteal pulses . Moreover, a considerable lack of inter-
observer agreement in the palpation of peripheral pulses has been shown .
Anteriorly the artery from above downward is separated from popliteal
surface of the femur by fatty tissue, the back of the knee-joint, and the
fascia covering the popliteus. Posteriorly, it is overlapped by the
Semimembranosus above, and is covered by the Gastrocnemius and Plantaris
below. In the middle part of its course the artery is separated from the
integument and fascia by a quantity of fat. On its lateral side, above,
are the Biceps femoris, and the lateral condyle of the femur; below, the
Plantaris and the lateral head of the Gastrocnemius. On its medial side,
above, are the Semimembranosus and the medial condyle of the femur; below,
the medial head of the Gastrocnemius .
The purpose of this communication is to report a new bedside method
of assessing patency of popliteal artery. As described by Ger et al,
flexion of the knees facilitates relaxation of the gastrocnemius making it
more accessible to palpation . Using the above information, I have found
that in a patient with patent popliteal artery, to and fro pulsatile
movement of the foot (in conjunction with heart beat) will be observed
when he sits in a high chair with legs crossed such that the popliteal
fossa of the leg being examined lies over the knee of the opposite leg.
The patient must sit on a high chair so that the popliteal fossa lies
against the knee cap of the opposite leg. The top leg should be completely
relaxed so the weight of the leg compresses the artery between the knee
cap of the lower leg and the proximal part of the tibia (Figs 1 and 2).
To my knowledge this method of assessing popliteal artery patency has
never been described before. It is likely that the specificity of the
method will be high but both sensitivity and specificity remain to be seen
and should be a subject for future studies.
References:
Collins R, Burch J, Cranny G, Aguiar-Ibáñez R, Craig D, Wright K, et
al. Duplex ultrasonography, magnetic resonance angiography, and computed
tomography angiography for diagnosis and assessment of symptomatic, lower
limb peripheral arterial disease: systematic review. BMJ 2007;334:1257-61.
Hirsch AT, Criqui MH, Treat-Jacobson D, Regensteiner JG, Creager MA,
Olin JW, et al. Peripheral Arterial Disease Detection, Awareness, and
Treatment in Primary Care. JAMA. 2001;286:1317-1324.
Khan NA, Rahim SA, Anand SA, Simel DL, Panju A. Does the clinical
examination predict lower extremity peripheral arterial disease? JAMA
2006; 295: 536-46.
Brearley S, Simms MH, Shearman CP. Peripheral pulse palpation: an
unreliable physical sign. Ann R Coll Surg 1992; 74: 169-71.
Myers KA, Scott DF, Devine TJ, Johnston AH, Denton MJ, Gilfillan IS.
Palpation of the femoral and popliteal pulses: a study of the accuracy as
assessed by agreement between multiple observers. Eur J Vasc Surg 1987; 1:
245-9.
Williams P, Ellis H, Berkovitz BKB, Gray HFRS. In: Gray’s Anatomy:
The anatomical basis of clinical practice. Ed 39, Churchill-Livingstone,
2005, ISBN 0443071683. pp 632.
Ger R. Palpation of the popliteal artery. Surgery 1966; 60: 615-6.
Competing interests:
None declared
Competing interests: No competing interests
The article by Collins et al is highly interesting and suggests that
contrast enhanced magnetic resonance angiography is more sensitive and
specific than computed tomography angiography or duplex ultrasonography in
ruling out stenosis greater than 50%. (1) What needs to be considered is
whether magnetic resonance angiography is equally sensitive in diagnosing
stenosis less than 50 %. In this regard, digital subtraction angiography
carries an upper hand. Digital subtraction angiography has been
consistently shown to be more sensitive in detecting lesser degrees of
stenosis. In addition magnetic resonance angiography is less sensitive in
distinguishing between severe stenosis and complete occlusion. (2) Another
advantage of digital subtraction angiography is that it can be used to
guide intervention unlike magnetic resonance angiography. (3)
The fact that digital subtraction angiography is more sensitive
compared to any other diagnostic modality and the fact that it is usually
necessary before or during any surgical intervention clearly makes it the
“gold standard” for detecting and evaluating peripheral arterial disease.
(4)
REFERENCES
1. Collins R, Burch J, Cranny G, Aguiar-Ibanez R, Craig D, Wright K,
et al. Duplex ultrasonography, magnetic resonance angiography, and
computed tomography angiography for diagnosis and assessment of
symptomatic, lower limb peripheral arterial disease: systematic review.
BMJ 2007; Jun 16;334(7606):1257.
2. Modaresi KB, Cox TC, Summers PE, Jarosz JM, Verma H, Taylor PR,
et al. Comparison of intra-arterial digital subtraction angiography,
magnetic resonance angiography and duplex ultrasonography for measuring
carotid artery stenosis. Br J Surg 1999; Nov;86(11):1422-6.
3. White C. Clinical practice. Intermittent claudication. N Engl J
Med 2007; Mar 22;356(12):1241-50.
4. Hentsch A, Aschauer MA, Balzer JO, Brossmann J, Busch HP, Davis K,
et al. Gadobutrol-enhanced moving-table magnetic resonance angiography in
patients with peripheral vascular disease: a prospective, multi-centre
blinded comparison with digital subtraction angiography. Eur Radiol 2003;
Sep;13(9):2103-14.
Competing interests:
None declared
Competing interests: No competing interests
We read with interest Collins et al.’s review on the imaging
modalities available for assessing peripheral arterial disease (PAD)
caused by atherosclerosis (1). Although atherosclerotic disease is the
primary cause of PAD, microvascular insufficiency may also play a role in
the pathogenesis of lower extremity PAD (2, 3), especially in persons with
diabetes (4-7). However, studies on the relationship of microvascular
disease and PAD are limited, largely due to the lack of useful tools to
evaluate the peripheral microcirculation.
The human retina provides a unique window that allows direct and non-
invasive visualization of the systemic microcirculation (8). Similar to
the peripheral microvessels, the retinal arterioles or venules are of 100-
300 microns in diameter (9). In recent years, there is a growing body of
literature showing that various structural changes seen in the retinal
microvasculature (e.g., variations in retinal arteriolar/venular caliber,
retinopathy lesions) are associated with a range of incident systemic
vascular diseases, such as hypertension, stroke, heart disease and
nephropathy, independent of traditional risk factors (8). Interestingly,
studies have also reported that retinal vascular changes may be associated
with risk of PAD. In the Rotterdam study, narrower retinal arteriolar
caliber was associated with lower ankle-arm index (10). Other prospective
studies show that the presence and severity of retinopathy as well as
focal and generalized retinal arteriolar narrowing may predict an
increased risk of lower extremity amputation in people with diabetes (4-
7). In the United Kingdom Prospective Diabetes Study, retinopathy was
similarly associated with incident PAD, though the association was of only
borderline statistical significance (11). These data thus suggest that
architectural alterations in the retinal microvasculature may reflect
peripheral microcirculatory dysfunction, which predisposes the development
and manifestation of PAD.
Since the currently available imaging modalities for PAD do not
capture the microvascular component of the condition, an assessment of
retinal vessels may provide a surrogate, albeit indirect, platform to
further our understanding of the peripheral microcirculation. Knowledge of
such may offer new insights into the pathogenesis of PAD and open new
avenues for therapeutic targets in people with PAD.
REFERENCES
1. Collins R, Burch J, Cranny G, Aguiar-Ibanez R, Craig D, Wright K,
et al. Duplex ultrasonography, magnetic resonance angiography, and
computed tomography angiography for diagnosis and assessment of
symptomatic, lower limb peripheral arterial disease: systematic review.
BMJ 2007;334:1257
2. Cooke JP. The pathophysiology of peripheral arterial disease:
rational targets for drug intervention. Vasc Med 1997;2:227-30.
3. Stewart KJ, Hiatt WR, Regensteiner JG, Hirsch AT. Exercise
training for claudication. N Engl J Med 2002;347:1941-51.
4. Moss SE, Klein R, Klein BE. The prevalence and incidence of lower
extremity amputation in a diabetic population. Arch Intern Med
1992;152:610-6.
5. Moss SE, Klein R, Klein BE. The 14-year incidence of lower-
extremity amputations in a diabetic population. The Wisconsin
Epidemiologic Study of Diabetic Retinopathy. Diabetes Care 1999;22:951-9.
6. Moss SE, Klein R, Klein BE, Wong TY. Retinal vascular changes and
20-year incidence of lower extremity amputations in a cohort with
diabetes. Arch Intern Med 2003;163:2505-10.
7. Klein R, Klein BE, Moss SE, Wong TY. Retinal vessel caliber and
microvascular and macrovascular disease in type 2 daibetes. XXI: The
Wisconsin Epidemiologic Study of Diabetic Retinopathy. Ophthalmology 2007;
Epub ahead of print May 29.
8. Wong TY, Mitchell P. Hypertensive retinopathy. N Engl J Med
2004;351:2310-7.
9. Levy BI, Ambrosio G, Pries AR, Struijker-Boudier HA.
Microcirculation in hypertension: a new target for treatment? Circulation
2001;104:735-40.
10. Ikram Mk, de Jong FJ, Wingerling JR, Witteman JC, Hofman A,
Breteler MM, et al. Are retinal arteriolar or venular diameters associated
with markers for cardiovascular disorders? The Rotterdam Study. Invest
Ophthalmol Vis Sci 2004;45:2129-34.
11. Adler AI, Stevens RJ, Neil A, Stratton IM, Boulton AJM, Holman
RR. UKPDS 59: Hyperglycemia and other potentially modifiable risk factors
for peripheral vascular disease in type 2 diabetes. Diabetes Care
2002;25:894-9.
Competing interests:
None declared
Competing interests: No competing interests
Authors' correction
In the section on patients' attitudes, the study by Visser and
colleagues (web reference 62: Patients' preferences for MR angiography and
duplex US in the work-up of peripheral arterial disease. Eur J Vasc
Endovasc Surg 2003;26:537-43) evaluated contrast-enhanced MR angiography,
not time-of-flight MR angiography as stated.
Competing interests:
None declared
Competing interests: No competing interests