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32 Endovascular Interventions forMale Infertility
411
validation. Patients must undergo thorough evaluation to
rule out non-vascular causes for ED (e.g. psychogenic,
neurogenic, hormonal) before these procedures are
considered.
7. Duplex USG is the rst-line imaging modality for
ED.
8. Angiography with angioplasty can be helpful in select
cases. Patients with documented internal pudendal ste-
nosis and conrmed vascular aetiology for ED may benet from these interventions.
9. Retrograde venous occlusion is treatment option for
ED due to venous leak.
10. Outcomes from interventional procedures for ED
vary widely. Patient selection, the underlying cause of
ED and technical aspects of the intervention can all
inuence the outcomes. Continued research and assessment are needed to better dene the role of interventional radiology in management of ED.
References
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treatment of priapism. J Emerg Med. 2004;26:325–9.
2. Eland IA, van der Lei J, Stricker BJ, etal. Incidence of priapism in
the general population. Adult Urol. 2001;57:970–2.
3. Montague DK, Jarow J, Broderick GA, etal. American Urological
Association guideline on the management of priapism. J Urol.
2003;170:1918–24.
4. Savoca G, Pietropaolo F, Scieri F, etal. Sexual function after highly
selective embolization of cavernous artery in patients with highow priapism: long-term follow-up. J Urol. 2004;172:644–7.
5. Hossein SN, Vikram D, Allen DS, et al. Priapism. Radiol Clin
North Am. 2004;42:427–43.
6. Kim N, Vardi Y, Padma-Nathan H, etal. Oxygen tension regulates
the nitric oxide pathway: physiological role in penile erection. J
Clin Invest. 1993;91:437–42.
7. Langenhuijsen JF, Reisman Y, Reekers JA, de Reijke TM.Highly
selective embolization of bilateral cavernous arteries for posttraumatic penile arterial priapism. Int J Impot Res. 2001;13:354–6.
8. NIH Consensus Conference. Impotence. NIH consensus development panel on impotence. JAMA. 1993;270(1):83–90.
9. Schwartz BG, Kloner RA.Clinical cardiology: physician update:
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10. Javaroni V, Neves MF. Erectile dysfunction and hypertension:
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2012;62:72–8.
11. Bacon CG, Mittleman MA, Kawachi I, et al. Sexual function in
men older than 50 years of age: results from the health professionals follow-up study. Ann Intern Med. 2003;139:161–8.
12. Heidelbaugh JJ. Management of erectile dysfunction. Am Fam
Physician. 2010;81:305–12.
13. Matn G. New treatments for erectile dysfunction. Fertil Steril.
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14. Montague DK, Jarow JP, Broderick GA, et al. Chapter 1: the
management of erectile dysfunction: an AUA update. J Urol.
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15. Valji K, Bookstein JJ. Transluminal angioplasty in the treatment of arteriogenic impotence. Cardiovasc Intervent Radiol.
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pure arteriogenic impotence. Br J Urol. 1994;73:561–5.
18. Rosen MP, Schwartz AN, Levine FJ, Greeneld AJ.Radiologic
assessment of impotence: angiography, sonography, cavernosography, and scintigraphy. AJR Am J Roentgenol. 1991;157:923–31.
19. Bilhim T, Casal D, Furtado A, et al. Branching patterns of the
male internal iliac artery: imaging ndings. Surg Radiol Anat.
2011;33:151–9.
20. Delcour C, Wespes E, Vandenbosch G, etal. Impotence: evaluation
with cavernosography. Radiology. 1986;161:803–6.
21. Suzuki K, Nishizawa S, Muraishi O, et al. Post-traumatic highow priapism: demonstrable ndings of penile enhanced computed
tomography. Int J Urol. 2001;8:648–51.
22. Gufral S, MacDonagh RP, Cavanagh PM.Bilateral superselective
arterial microcoil embolization in delayed post-traumatic high-ow
priapism. Postgrad Med J. 2001;77:193–4.
23. Görich J, Ermis C, Krämer SC, et al. Interventional treatment of
traumatic priapism. J Endovasc Ther. 2002;9:614–7.
24. Touge H, Watanabe T, Fujinaga T, Kawabata M. Post-traumatic
high-ow priapism: a case report. Int J Urol. 1999;6:623–6.
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report. Can Assoc Radiol J. 1997;48:105–7.
26. Zumbé J, Drawz G, Wiedemann A, et al. Indications for penile
revascularization and long-term results. Andrologia. 1999;31:83–7.
27. Basche S, Eger C, Elsebach K, Ulshofer B. Veno-occlusive dysfunction as a cause of erectile impotence: therapy of venous leak
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28. Schild HH, Muller SC, Mildenberger P, Strunk H, Kalternborn H,
Kersjes W, etal. Percutaneous penile venoablation for treatment of
impotence. Cardiovasc Intervent Radiol. 1993;16:280–6.
29. Rebonato A, Auci A, Sanguinetti F, Maiettini D, Rossi M,
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Part III
Non-vascular Interventions
Image-Guided Biopsy
NehaBaijal andS.H.Chandrashekhara
33
Key Messages
1. The use of image guidance improves the accuracy and
safety of biopsy and almost any lesion which is visible
on any modality can be sampled.
2. A thorough pre-procedure workup to assess indications, contraindications, patient, and lesion suitability
is essential to maximize yield and minimize
complications.
3. A review of the available imaging is essential to identify
the target lesion, choose the appropriate image guidance,
and plan the approach and biopsy track.
4. In a case with multiple lesions, the most easily accessible lesion with highest likely viable tissue yield and lowest risk of complications must be chosen.
5. The shortest path with minimal intervening normal tissue is generally the safest. This may be achieved by
choosing the right image guidance, changing the patient
position and various techniques like triangulation, compression, and hydrodissection.
6. The choice of biopsy device is based on size and location of the lesion, operator preference and cost.
7. Ultrasound is the most widely used modality for guidance due to its wide availability and real-time visualization capabilities. CEUS can be used to improve lesion
conspicuity.
8. CT guidance provides access to areas where US conspicuity is limited by physics and anatomy, such as the
lung, mediastinum, retroperitoneum, and bones.
9. MR guidance is used when both US and CT do not provide adequate lesion visualization.
10. Recent advances include the use of CEUS, MRI, and
fusion imaging to guide biopsies.
33.1 Introduction
While imaging alone can provide a diagnosis in many cases,
histopathological conrmation is often required. Tissue sampling may be required in order to conrm a diagnosis, for
immunohistochemical typing, to identify certain molecular
markers for targeted therapy, and to conrm metastasis or
recurrence of cancer.
Tissue sampling can be minimally invasive like neneedle aspiration cytology (FNAC) and core biopsy; or surgical as in excisional biopsy. FNAC is the least invasive
technique, well suited for small lesions (<1 cm in longest
dimension), with the lowest risk of complications owing to
the use of thin needles (typically 21G) (Fig.33.1). However,
the amount of tissue obtained is limited, resulting in low sensitivity, high false negative rates, and the need for an on-site
cytopathologist to conrm the adequacy of the sample in
order to improve the yield. With the use of cell blocks, immunohistochemical information can be obtained even with
FNAC; however, that too suffers from low sensitivity and
high false negative rates.
a
b
N. Baijal
Department of Radiodiagnosis and Interventional Radiology, All
India Institute of Medical Sciences, Delhi, India
S. H. Chandrashekhara (
Department of Radiodiagnosis and Interventional Radiology,
IRCH, All India Institute of Medical Sciences, Delhi, India
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024
S. H. Chandrashekhara (ed.), Textbook of Interventional Radiology, https://doi.org/10.1007/978-981-97-9601-4_33
*)
Fig. 33.1 Commonly used FNAC needles. (a) Lumbar puncture nee-
dle and (b) Chiba needle
415
416
N. Baijal and S. H. Chandrashekhara
Core biopsy can be done by percutaneous, endoluminal,
or transvenous routes. Tissue cores ranging from 10 to
20mm can be obtained using different biopsy devices and
guidance techniques. Imaging modalities used to guide
biopsy procedures include ultrasound (US), contrastenhanced ultrasound (CEUS), uoroscopy, mammography,
computed tomography (CT), and magnetic resonance imaging (MRI). The choice of imaging modality used for guiding
the biopsy depends on factors such as visibility of lesion,
surrounding anatomy, and planned route of access. Other
factors to consider include availability, cost, and radiation
exposure.
The use of excisional biopsy is limited to cases in which
surgery may be curative, risk of tract seeding from a percutaneous biopsy is high, or when there would be no change in
the surgical plan irrespective of the biopsy result.
In this chapter, we discuss various biopsy devices and
techniques for performing an image-guided biopsy, including the pre-procedure workup, procedure, and postprocedure care. After a general discussion of the principles
to be followed for US-, CT-, and MRI-guided biopsies, we
then outline organ-specic and disease-specic
considerations.
33.2 Biopsy Devices
There are several types of biopsy needles that differ in their
length, caliber, tip, and mechanism of acquisition of the sample. Selection of the biopsy device depends on various factors such as the experience and preference of the interventional
radiologist, the size and anatomical location of the lesion,
surrounding structures in the planned biopsy tract, and the
amount of tissue needed for biopsy [1].
Broadly speaking, there are two types of biopsy needles—
aspiration and cutting needles.
Aspiration needles have beveled or circumferentially
sharpened tips. Examples of aspiration needles with a beveled tip include Chiba (Cook Medical, Inc., Bloomington,
IN) and spinal needles, which range from 20 to 23G and have
a thin wall. Greene (Cook Medical, Inc., Bloomington, IN),
Turner (Cook Medical, Inc., Bloomington, IN), and Franseen
(Cook Medical, Inc., Bloomington, IN) needles are examples of aspiration needles with a circumferentially sharpened
tip. These are suitable for cytologic and microhistologic
specimens [2].
Cutting needles are used to provide histologic specimens
(Fig.33.2). The most commonly used sizes range from 18 to
20G for most organs while large-gauge needles such as 10G
are used for musculoskeletal biopsies. Bone biopsy is done
a
b
c
Fig. 33.2 Schematic gure of biopsy procedure. (a) Biopsy needle is
placed adjacent to target lesion. (b) The biopsy needle is pierced within
the lesion. (c) Biopsy gun is red to obtain the tissue sample
using trephine and combination needles which include features of both cutting and trephine needles. Trephine needles
include the 10G Craig (Becton, Dickinson and Company,
Rutherford, NJ), the 12G Ackerman (Cook Medical, Inc.,
Bloomington, IN), and the Elson (Cook Medical, Inc), while
combination needles include the Jamshidi (Manan Medical
Products, Wheeling, IL), Ostycut (C.R. Bard, Covington,
GA), and Osteosite (Cook Medical, Inc).
Depending on the location of the notch, cutting needles
may be end- or side-cutting. End-cutting needles provide a
cylindrical core of tissue by a sharpened hollow cannula
which res over a stationary trocar. Side-cutting needles provide a semi-cylindrical core by a beveled cannula that res
over an inner stylet with a central notch.
Based on the ring mechanism, there are three kinds of
biopsy devices—manual, semi-automatic, and automatic:
• Manual biopsy needles are used most commonly for bone
biopsies where the use of a combination of hammering
and a rotatory motion are required to advance the needle
through the bone.
• Semi-automatic biopsy devices have an outer guiding
needle and an inner stylet with a ring mechanism that
allows the stylet to be advanced rst and then red.
• Automatic biopsy devices have a rapid ring mechanism
which lowers the risk of needle deection, reduces patient
discomfort, and provides a larger amount of tissue with
minimal fragmentation. All end-cutting devices are fully
automated, while side-cutting devices can be manual,
semi-automatic, or automatic [3, 4].
33 Image-Guided Biopsy
417
The “coaxial technique” is the most commonly used technique for image-guided biopsy, in which the outer guide
needle is placed into the target tissue once and multiple cores
can be taken by the inner needle without repeatedly traversing the entire path. This increases the tissue yield and also
reduces the risk of complications such as bleeding.
Advantages of this technique include reduced risk of injury
to the surrounding tissue, reduced procedure time, reduced
need for image guidance for each pass, and more secure
access. After obtaining the sample, gel foam can be injected
along the tract in order to minimize bleeding in highly vascular organs like the liver. Similarly, post-biopsy pneumothorax can also be aspirated using the same access in case of
CT-guided lung biopsy. The coaxial technique can also be
used in manual biopsy devices. Radiofrequency ablation
(RFA) of bone lesions like osteoid osteoma can be done in
the same setting by placing the RFA probe through the outer
cannula of the bone biopsy needle.
However, taking multiple cores from the same site lowers
the tissue yield from subsequent passes. Various needle
designs have been described in order to overcome this problem. A side-exiting needle that can be rotated by 45 degrees
after each pass has been described [5]. Curved inner needle
is another modication that helps in taking samples from different sites within the lesion [6].
Another limitation of the coaxial technique is that the
inner needle is small in size and yields less amount of tissue.
Detachable automatic biopsy devices have also been developed to allow the outer cannula to function as a guide as well
as the cutting needle [1].
In automatic biopsy devices, the inner needle and outer
cutting sheath are red simultaneously. These needles are
usually used without the coaxial technique. These devices
provide a larger tissue yield in a single core such as in breast
biopsy and are also useful in tissues that tend to “slip” during
placement of the outer needle like the omentum. However, it
is more traumatic as repeated punctures are required for multiple passes, leading to an increased risk of complications
and the risk of losing access. For most indications, semiautomatic biopsy guns with the coaxial technique are preferred as they are less traumatic, provide better control over
the access, and allow multiple passes and the instillation of
any drug or embolizing agent through the outer cannula
(Fig.33.3).
There are other devices for specic organs. One of them
is vacuum-assisted biopsy used for breast lesions. It has a
signicantly higher tissue yield than conventional core needle biopsy and may even be curative for small lesions.
Another special device is the transjugular liver biopsy set
used for transvenous access in patients with uncorrectable
coagulopathy or ascites.
ab
Fig. 33.3 Commonly used biopsy guns. (a) Automatic and (b)
Semiautomatic biopsy guns
33.3 Pre-Procedural Evaluation
A review of the available imaging and laboratory investigations should be done. The aim is to identify the lesion and its
suitability for biopsy, plan the access, and choose the appropriate technique. In a patient with multiple lesions, selection
of the biopsy target should be based on the lowest risk and
highest diagnostic yield. Based on the site of the lesion and
planned access, risk of bleeding is assessed. Supercial
structures like cervical lymph nodes, thyroid, breast, and soft
tissue lesions in the extremities are considered to be at low
risk of bleeding while intrathoracic and intra-abdominal procedures carry a high bleeding risk. Further assessment should
be done for bleeding risk due to patient factors such as
thrombocytopenia, coagulopathy, liver disease, or pharmacotherapy. Laboratory investigations including platelet count
and PT-INR and the appropriate correction should be done as
per the guidelines of the Society of Interventional Radiology
(SIR), which is discussed in detail in Chap. 6.
Patients planned for intrathoracic and intra-abdominal
biopsies are asked to report fasting for at least 6 hours.
Patients planned for transrectal ultrasound (TRUS)-guided
biopsies require bowel preparation for which laxatives are
418
administered one day prior to the procedure. In case transvenous biopsy is planned, an ultrasound Doppler examination
of the planned access site is necessary in order to rule out
pre-existing thrombosis. Similarly, a screening USG of the
planned target lesion should be done, ideally by the interventional radiologist who will be performing the biopsy, in order
to identify the lesion and plan the best approach. If the lesion
is not visible on USG, CT or MRI guidance may be required.
On the day of the planned biopsy, all regular medications,
especially antihypertensives, should be taken. Insulin and
oral anti-diabetic drugs may be omitted if the patient has
been asked to report fasting in order to avoid hypoglycemia.
Antiplatelets and anticoagulants are to be withheld as per
SIR guidelines.
Written informed consent is essential and must be taken
after explaining the risks and expected benets of the procedure to the patient. Intravenous access is secured prior to the
procedure, preferably with at least a 20G cannula, in order to
be able to administer medications in the event of an emergency such as a vasovagal reaction. The patient should be
provided with a disposable gown and covered adequately to
ensure patient comfort and privacy throughout the procedure. Patient positioning depends on the planned access.
However, patient comfort must be ensured using pillows and
sheets, as an uncomfortable patient is more likely to be
uncooperative.
General complications of all biopsy procedures include
pain, skin discomfort, bleeding, vasovagal syncope, infection, and needle-tract seeding. Patients must be counseled
regarding these general complications and any specic complications related to their disease prior to performing the
procedure.
33.4 Ultrasound-Guided Biopsy
It is the most commonly used and widely available technique
of image-guided biopsy (Fig.33.4). The biggest advantage
of USG is the real-time visualization of the needle during the
entire procedure, thereby increasing the safety and accuracy
of the procedure. Other advantages include wide availability,
low cost, and absence of radiation exposure. However, it is
operator dependent and has a shallow learning curve as it
requires the operator to coordinate the simultaneous use of
the ultrasound probe and the needle with both hands. Also,
USG has limited use in certain anatomic areas where US
artifacts lead to poor visualization of the lesion such as the
lung, mediastinum, bowel, retroperitoneum, and bones.
Any ultrasound probe that is appropriate for performing
the diagnostic USG of the lesion can be used to guide a
biopsy. For an intra-abdominal lesion, curvilinear transducer
is used, while for supercial structures like the breast, linear
N. Baijal and S. H. Chandrashekhara
Fig. 33.4 Abdominal lymph node biopsy done using ultrasound
guidance
transducer is used. TRUS is used for the prostate and transvaginal ultrasound (TVS) can be used for sampling vaginal,
cervical, and adnexal lesions.
Patient positioning should be done so that both the patient
and operator are comfortable.
There are two techniques of guiding the needle using
USG:
• In-plane technique: As the name suggests, the needle is
kept in the same plane as the ultrasound beam. This allows
visualization of the entire length of the needle and is thus
useful in critical areas such as the liver and kidney, where
there is high risk of injury to surrounding structures.
• The out-of-plane technique is useful where there is less
space for the probe to be placed, such as the neck. The
needle and the ultrasound probe are kept perpendicular to
each other and the cross-section of the needle is visible on
USG.It is important to swipe the probe in order to conrm the position of the needle tip prior to taking a biopsy.
This technique is avoided in deep-seated structures as the
entire length of the needle is not visible throughout the
procedure.
Needle visualization may be difcult even with an in-
plane approach. In such cases, other techniques such as electronic beam steering, injecting air into the coaxial needle,
bouncing the needle with B-mode or Doppler USG, scoring
the needle tip with a Kelly clamp, and turning off harmonic
imaging for deeper lesions can help. The overall gain and
time gain compensation settings should be optimized for the
target lesion with the focal zone placed at the level of the
lesion. For the biopsy of deep lesions, compression by the
ultrasound probe reduces the abdominal wall thickness, dis-
33 Image-Guided Biopsy
419
places bowel loops, improves visualization of deeper structures, shortens the needle path, and xes mobile masses [1,
7]. Color Doppler should be used to identify the location of
blood vessels around the site of biopsy in the organ being
biopsied as well as in surrounding structures including the
chest or abdominal wall [4].
Recently, CEUS has also been found useful to improve
lesion conspicuity during biopsy, especially for isoechoic
lesions in the liver and kidney. Standard amount of ultrasound contrast agent (2.4 mL Sonovue) may be used just
prior to the procedure or during the procedure. Sampling the
most avidly enhancing part of the lesion is likely to yield
viable tissue, while non-enhancing areas are more likely to
be necrotic. CEUS guidance has been shown to improve
lesion conspicuity and histopathologic yield of tissue in focal
liver lesions, as well as breast lesions that are poorly visualized on grayscale USG [8, 9]. Case series have also shown
that CEUS guidance improves the yield in biopsy of musculoskeletal soft tissue lesions [10].
33.5 CT-Guided Biopsy
Traditionally, real-time visualization was not possible with
CT guidance. However, with the capability of CT uoroscopy, real-time guidance is also possible, albeit with an
increased radiation exposure to the patient as well as the
operator. The biggest advantage is the superior visualization
of the needle and the lesion, which is not hindered by air or
bone. The superior spatial and contrast resolution of CT
allows a clear depiction of surrounding structures. The learning curve is also steeper than for US-guided biopsies. Its
drawbacks are that it is more time-consuming, expensive,
and involves the use of ionizing radiation [1].
CT is the preferred modality for guiding percutaneous
biopsy of lesions in the lung, mediastinum, retroperitoneum,
and bones (Fig.33.5). Once the patient has been positioned
(prone for retroperitoneal or spinal lesions; supine, prone or
lateral for lung lesions), a limited helical scan of the area of
interest is taken. A 3D reconstruction allows planning of the
exact puncture site and needle tract. Contrast-enhanced scan
may be done in case of isodense lesions, lesions close to ves-
sels, or necrotic lesions to identify the safest site likely to
yield viable tissue. The slice in which the lesion is best seen
in its longest dimension is chosen. In case cranial or caudal
angulation is required in order to get adequate sample from
the lesion or to avoid vital structures, the gantry may be tilted
appropriately (if the CT machine allows this feature) [11].
This is known as the “triangulation” technique in which an
out-of-plane cranial or caudal needle entry is made with an
angled approach to avoid critical structures and reach the
lesion. This is particularly useful to accurately target upper
abdominal lesions in the adrenal, kidney, retroperitoneum,
and liver by an extrapleural, extraperitoneal route with low
risk of complications such as pneumothorax [12].
An external grid or scale is placed on the skin over the
selected slice using the laser beam of the CT gantry. A limited axial scan of 3–5 slices is taken at this site in order to
select the needle entry site. Local anesthesia is then instilled
at the selected site of needle entry. Based on the planned
angle and length of trajectory, the needle is advanced up to a
depth of 1–2cm. Another limited scan of 3–5 slices is taken
in order to conrm the needle entry site and projected path.
The distance from the needle tip to the lesion is measured on
the image and the needle is advanced into the lesion. Needle
should always be advanced swiftly but gently and the patient
may be asked to hold his/her breath while the needle is
advanced in order to minimize trauma to surrounding tissue.
Once the tip of the needle has been conrmed to be within
the lesion on check scan, the inner stylet is removed and the
biopsy gun is advanced through it. Another check scan is
done after the gun has been advanced completely and then
red. Multiple cores are taken in quick succession and placed
in formalin solution. If other molecular, immunohistochemical, or genetic tests are planned, the specimen may be placed
in separate containers as necessary.
The blunt stylet may be placed in between passes to minimize bleeding. The dwell time of the needle in the tissue
should be minimized as much as possible to reduce complications. A check scan may be taken prior to removal of the
outer cannula in case there is suspicion of bleeding, pneumothorax, or needle displacement. Gel foam prepared with
iodinated contrast may be injected along the tract in case of
bleeding. In case of mild to moderate pneumothorax, the air
abc
Fig. 33.5 CT-guided biopsy. (a) Left adrenal mass sampled by a direct posterior approach with the patient in lateral oblique position. (b) Trans-
sternal biopsy of anterior mediastinal mass. (c) Left upper lobe lung mass
420
N. Baijal and S. H. Chandrashekhara
can be aspirated using a three-way cannula, while large
pneumothorax with signicant lung collapse requires the
placement of a pigtail catheter or intercostal drain. After the
procedure, the patient should be instructed to lie with the
puncture site in the dependent position so that it is compressed by the patient’s body weight. This minimizes local
bleeding and also prevents the aspiration of blood into the
contralateral lung in case of lung biopsies.
CT uoroscopy is a useful technique as it combines the
real-time capability of uoroscopy with the spatial and contrast resolution of CT.However, this comes at the expense of
an increased radiation dose to the patient as well as to the
operator. It is most commonly used for percutaneous transthoracic biopsy of lung nodules—uoroscopy allows the
visualization of a lung nodule as it moves with respiration so
that the needle may be positioned within the nodule while
sampling. CT uoroscopy has also been used for small liver
lesions, especially those near the diaphragm, and for mesenteric or omental masses that are intermittently surrounded by
bowel. It can reduce the procedure time and the number of
pleural punctures and avoid hitting the ribs during needle
advancement. The various ways to minimize radiation exposure during CT uoroscopy include the use of intermittent
uoroscopy, low kV and low mA technique, small slice
thickness, and use of dedicated needle holders to keep the
operator’s hands away from the primary beam. The postprocedure CT can also be done in a low-dose setting to
reduce the radiation dose [1, 13–15].
33.6 MRI-Guided Biopsy
The use of MRI as a guide for biopsies is limited due to its
high cost, long procedure time, limited availability, and the
need for MRI-compatible hardware. However, sometimes it
may be the only modality in which the lesion is seen, thereby
making it the only imaging modality that can be used to
guide the biopsy.
The bulk of the MRI gantry and inaccessibility inside the
bore limited the use of MRI to guide interventions. However,
with the development of wide-bore machines and lighter
magnets, accessibility for interventions has improved. With
the development of MRI-compatible hardware, openconguration MRI systems, ultrafast sequences, and MRI
uoroscopy, MRI-guided interventions have become more
feasible. The advantages of MRI include a superior contrast
resolution, the ability to visualize vessels without contrast,
multiplanar imaging, and lack of ionizing radiation. It is
essential to screen the patient for any contraindications to
MRI such as cardiac pacemakers, brainstem implants, metallic prostheses, and claustrophobia. Special MR-compatible
biopsy devices are required, which do not heat up and show
minimal susceptibility artifacts allowing visualization of the
needle.
MRI-guided biopsy is most commonly used in breast
lesions that are not seen on mammography and USG.MRIguided prostate biopsy is also indicated in similar situations
when there is high clinical suspicion based on PSA levels,
and blind or TRUS-guided biopsy yields negative results. It
has been found useful in pediatric and obstetric patients
owing to the lack of ionizing radiation. It can also been used
for biopsy of bone marrow lesions not seen on any other
modality and liver lesions that are poorly delineated on USG
or CT or those which are located near the dome of diaphragm
[16–18].
33.7 Specic Organ Considerations
33.7.1 Head andNeck
FNAC from thyroid nodules and cervical lymph nodes is the
most commonly performed procedure. While sampling thyroid nodules, it must be remembered that the thyroid is a
highly vascular organ. Needle dwell time in the thyroid
should be minimized in order to prevent contamination of the
cells with blood which lowers the yield of FNAC.
Cervical lymph nodes are arranged in chains along the
jugular veins and the carotid vessels; therefore, care must be
taken not to injure these major vessels when performing a
biopsy.
Parotid masses are occasionally sampled; cystic masses
are more suited for FNAC.Care must be taken not to injure
the facial nerve by keeping the needle parallel to the skin and
avoiding deeper trajectories.
CT guidance is used for biopsy of skull base lesions.
Topical prilocaine applied 30minutes prior to the procedure
helps to reduce the pain and makes the patient more
cooperative.
More detailed discussion of biopsies in the head and neck
region is done in a separate chapter.
33.7.2 Breast
A detailed discussion on breast interventions is covered in
another chapter. Typically, a 14G needle is used and at least
5 cores of 20mm length each are obtained for adequate analysis. The biopsy gun must be kept as parallel to the chest as
possible to avoid inadvertent injury to the pectoralis muscle,
chest wall and underlying pleura. The internal thoracic artery
should be avoided when sampling medial masses. Breast
masses tend to slip owing to the hard mass in surrounding
soft glandular and fatty tissue. Thus, it is important to immo-
33 Image-Guided Biopsy
421
bilize and support the mass using the ultrasound probe or the
operator’s hand. The patient should be instructed not to lift
heavy weights or do heavy work using the upper limb for at
least 24hours. An ice pack should be placed over the site of
the biopsy in order to reduce the pain and swelling.
33.7.3 Lung
Biopsy is indicated for lung nodules, primary or secondary
lung masses, and occasionally to characterize diffuse lung
disease. While most cases of percutaneous lung biopsy are
suited to CT guidance, biopsy of peripheral pleural-based
masses can be done under USG guidance. While using USG
guidance, color Doppler is helpful in differentiate the hypovascular mass from the surrounding atelectatic lung with
normal vascularity. Ultrasound guidance has been found to
be faster, safer, and more accurate than CT guidance for
peripheral lung and pleural lesions >1cm in size [19].
The patient is positioned according to the location of the
mass and the planned biopsy tract. It is preferable to position
the biopsy-side down by keeping the target lesion and the
needle tract below the level of the left atrium. Some basic
principles to be followed are that a minimum amount of lung
parenchyma must be traversed and ssures, large vessels,
and diseased lung tissue (such as bullae, emphysema) should
be avoided. For small subpleural lesions, however, the shortest route may not necessarily be the best because of the risk
of needle dislodgement from the lung into the pleural space.
This occurs due to insufcient lung tissue to provide a stable
needle position, leading to an increased risk of pneumothorax and necessitating additional pleural punctures. To avoid
this, an oblique path with a long transpulmonary route is preferred. This provides more stability and scope for adjustment
of the needle course without having to puncture the pleura
again [1].
When the lung mass is located more centrally, an attempt
must be made to direct the needle parallel to the mediastinal
vessels and not toward them, so that they are not injured
when the biopsy gun is red. Bronchoscopic biopsy should
be considered for central masses that are accessible from
major bronchi.
The patient must be asked to hold the breath in midexpiration while piercing the pleura. Once the needle has
pierced the pleura, the rest of the procedure must be completed as fast as possible to minimize pneumothorax and
bleeding complications as the needle causes injury to the
lung and pleura with each respiratory movement. Similarly,
needle removal or exchange should be done during expiration. An immediate post-procedure scan is done to look for
chest radiograph is performed after 4 hours to look for a
delayed pneumothorax.
Complications of percutaneous lung biopsy may be minor
such as pneumothorax not requiring intervention, ground
glass opacity around the lesion due to hemorrhage, and transient hemoptysis. Major complications include pneumothorax requiring intervention, hemothorax, air embolism, needle
tract seeding, and death. While the rate of minor complications is higher with core biopsy, the rate of major complications is similar for both aspiration and core biopsy. Factors
affecting the complication rate include needle size, length of
traversed lung parenchyma, size and depth of the lesion, and
operator experience. Larger needles, especially among aspiration needles, longer transpulmonary path, and smaller and
deeper lesions are associated with a higher risk of pneumothorax and hemoptysis. Another factor that affects the risk of
pneumothorax is patient position—lateral decubitus position
with the biopsy-side down is considered the safest [20–23].
Pleuritic pain is common in the immediate post-procedure
period if the pleura has been breached and the patient must
be counseled and given analgesics appropriately.
Pneumothorax is the most common complication with a
reported incidence of 15–38% and the need for chest tube
insertion in 5–10% of patients who undergo percutaneous
transthoracic lung biopsy. The PEARL approach has been
advocated to reduce the risk of pneumothorax. It includes
positioning the biopsy-side down, removing the needle during expiration, using an autologous blood patch seal, rapid
rollover, and pleural patching. Biopsy-side down is the position in which the lesion and the needle tract is below the left
atrium. Autologous blood (~10 mL) withdrawn from the
patient prior to start of the procedure is injected during needle removal to seal the biopsy tract while the patient is asked
to maintain forced expiration. Immediately after needle
removal, the patient is rolled into a puncture-site down position before the check scan [24].
In case pneumothorax does occur, management depends
on the amount and timing of pneumothorax. Oxygen is
administered by nasal cannula at 4–6L/min and 100% concentration. If the pneumothorax is detected intra-procedure
with the needle still in the lung parenchyma, the parenchymal tract is sealed using autologous blood clot and the needle
is withdrawn into the pleural space. Immediate manual aspiration of the air is done using a three-way connector. After
that, 20mL of freshly withdrawn blood is injected into the
pleural cavity and the needle is withdrawn in held expiration.
For large pneumothorax, it may be necessary to place a pigtail catheter or intercostal drainage tube. In case a delayed
pneumothorax is detected, management depends on the size
of the pneumothorax and the clinical status. If the thickness
of pneumothorax is <3cm at the apex or<2cm at the hilum,
and the patient is asymptomatic, no intervention is required.
However, symptomatic or larger pneumothoraces require
manual aspiration or drainage tube (at least 10F) placement
[24].
422
N. Baijal and S. H. Chandrashekhara
33.7.4 Mediastinum
While CT guidance is most commonly used, USG can be
used to biopsy mediastinal masses that are in contact with
the chest wall. A direct mediastinal, extrapleural approach is
preferred in most cases to reduce the risk of pneumothorax.
The approach depends on the compartment in which the
mass is located. For prevascular and visceral compartment
masses, anterior suprasternal, parasternal, or trans-sternal
approach may be used. If the mass or mediastinal fat is in
contact with the anterior chest wall lateral to the sternum, the
parasternal approach is used. Care must be taken not to injure
the internal thoracic artery. If the lesion is not accessible by
parasternal route, the trans-sternal route can be used. This is
done exclusively under CT guidance, and can be performed
using an 18G needle—a bone biopsy gun is not needed to
cross the sternum. If the lesion is located above the level of
the aortic arch, the suprasternal approach can be taken. The
patient is positioned in semi-recumbent position with pillows to support the back and the CT gantry is tilted
craniocaudally to allow direct visualization of the needle
path. Other techniques for the suprasternal approach include
hyperextending the neck, using the triangulation technique,
and using ultrasound guidance with a small footprint probe
placed in the suprasternal notch.
Paravertebral, subcarinal, and other posterior mediastinal
masses are accessed by the paravertebral approach. The
patient is laid prone and a salinoma is created using normal
saline in order to hydrodissect through the tissues, provide
space for the biopsy needle, and avoid traversing the lung.
Sometimes an extrapleural approach may not be possible
due to the location and size of the mass. In such cases, traversing through the lung may be avoided by advancing the
needle through a pre-existing pleural effusion or an iatrogenically created pneumothorax. If no other approach is possible, a transpulmonary approach is used. However, crossing
the visceral pleura and lung twice to reach the mediastinal
lesion substantially increases the risk of pneumothorax [1,
25–27].
33.7.5 Liver
The indications for sampling in diffuse liver disease include
identifying the cause of chronic liver disease (CLD), detection of non-alcoholic steatohepatitis (NASH), autoimmune
hepatitis (AIH), graft rejection in liver transplant and quantication of liver fat or iron content.
Focal liver lesions can often be diagnosed on multiphase
CT or MRI examinations using LIRADS and biopsy is not
always required. However, for LR4 and LR-M lesions and
for patients in whom LIRADS cannot be applied, such as
children, patients of Budd-Chiari syndrome, and those with
known cancer, sampling may be required to prove the nature
of the liver lesion.
Image-guided liver biopsy can be done percutaneously or
by the transvenous route. Percutaneous biopsy of the liver is
most commonly done using USG guidance. CEUS is used to
enhance the conspicuity of focal liver lesions and to identify
the viable enhancing portion in necrotic lesions in order to
improve the diagnostic yield [8, 28]. CT-guided biopsy is
done for small focal liver lesions that are poorly visualized
on USG due to the patient’s body habitus, location near the
dome of diaphragm, intervening ribs, pleura, or bowel gas.
An immediate pre-procedure contrast-enhanced scan can be
done to improve lesion conspicuity. However, lesions that
become isodense to the liver on delayed phases and artifacts
from the needle tip may impair the visibility of lesion [29].
MRI-guided biopsy is done for lesions that are poorly seen
on both USG and CT, especially those <20 mm in size.
MR-guided freehand biopsy of liver lesions has been found
to have higher clinical success, lower complication rates, but
longer procedure times than CT guidance [30].
The liver is a highly vascular organ and it moves with
respiration. In case of liver biopsy for diffuse liver disease,
the site with maximum amount of liver parenchyma is chosen, avoiding the major vessels and bile ducts. For focal
lesions, the approach may be epigastric, subcostal, or intercostal depending on the location of the lesion. Since capsule
is the most pain-sensitive part, adequate local anesthesia is
given till the capsule in order to prevent the patient from suddenly moving when the capsule is pierced. Major vessels
including the hepatic veins, main portal vein, and their
branches must be avoided as they do not recoil if injured due
to the surrounding brous parenchyma. Gel foam “plug”
prepared in normal saline should be routinely injected along
the biopsy tract till the liver capsule at the end of the procedure. The patient must be monitored for the development of
ascites (hemoperitoneum) immediately and for up to 4hours
after the procedure by ultrasound. Volume redistribution in
CLD leads to reduced amount of parenchyma available for
sampling, and the development of coagulopathy and ascites
as the patient decompensates. In such cases, transvenous
route is preferred.
Transjugular liver biopsy (TJLB) is indicated in patients
with ascites and/or coagulopathy. It can also be done in cases
of failed percutaneous biopsy, morbid obesity, atrophic liver,
suspected amyloidosis, cardiac cirrhosis, peliosis hepatis,
chronic kidney disease, and hereditary hemorrhagic telangiectasia, in which the risk of bleeding is high. The right internal jugular vein (IJV) is the preferred site of access. If the
right IJV is thrombosed, alternatives such as left IJV, the