I
“MAGNETIC RESONANCE IMAGING EVALUATION OF
PERIANAL FISTULAS”
BY
Dr. RASHMI ARAVIND PATELRM.B.B.S
Dissertation Submitted to theRajiv Gandhi University of Health Sciences, Bengaluru, Karnataka.
In partial fulfilment of the requirements for the Degree
DOCTOR OF MEDICINEIN
RADIODIAGNOSIS
Under the guidance ofDr. RAJKUMAR. S. YM.D,DNB, FRCR(UK)
ASSOCIATE PROFESSOR
DEPARTMENT OF RADIODIAGNOSIS,SSIMS & RC, DAVANGERE,
KARNATAKA,2018.
ABBREVIATIONS
CT-Computed TomographyFID- Free Induction Decay
MRI-Magnetic Resonance ImagingNMR -Nuclear Magnetic Resonance; RF-
Radiofrequency;
SNR -Signal-To-NoiseRatio;TR –Repetition Time
VII
LISTOFTABLES
TableNo. Table PageNo.
1 AGE 33
2 GENDER 34
3 SWELLING 35
4 DISCHARGE 36
5 NUMBER OFEXTERNALOPENINGS 37
6 INTERSPHINCTERICFISTULOUSTRACT MRI 38
7 HORSE SHOE SHAPED RAMIFICATION MRI 39
8 TRANSPHINCTERIC TRACTMRI 40
9 INTERNALOPENING MRI 41
10 EXTERNALOPENING 42
11 NUMBER OF INTERNALFISTULATRACTS 43
12 ST.JAMES'SUNIVERSITYHOSPITALCLASSIFICATIONTYPE 44
13 SUPRA LEVATOREXTENSION 45
VIII
LIST OF FIGURES
TableN
FiguresPageNo.
1 NORMALMRI ANATOMYOFTHE ANALREGION 10
2 ANATOMYOFTHE ANALREGION 8
3 NORMALMRI ANATOMYOFTHE SPHINCTERS. 13
4 ST. JAMESUNIVERSITY
HOSPITALCLASSIFICATIONFOR MRI
15
5 TYPEOF FISTULA IN RELATION TO ANATOMY 17
6 THE PARKSCLASSIFICATION 19
7 EXTERNALOPENINGOF FISTULA 20
8 TREATMENT OPTIONS OF FISTULA 23
IX
LIST OF GRAPHS
Table No.
GRAPHS PageNo.
1 AGE 33
2 GENDER 34
3 SWELLING 35
4 DISCHARGE 36
5 NUMBER OFEXTERNALOPENINGS 37
6 INTERSPHINCTERICFISTULOUS TRACTMRI 38
7 HORSE SHOE SHAPED RAMIFICATION MRI 39
8 TRANSPHINCTERIC TRACTMRI 40
9 INTERNALOPENINGMRI 41
10 EXTERNALOPENING 42
11 NUMBEROFINTERNALFISTULATRACTS 43
12 ST. JAMES'SUNIVERSITYHOSPITALCLASSIFICATIONTYPE 44
13 SUPRA LEVATOREXTENSION 45
X
LIST OFIMAGES
IMAGENo IMAGE
PageNo.
1 EXTERNALOPENINGOFANALFISTULA 65
2 PROBE TEST 65
3 FISTULECTOMYPROCEDURE 65
4 T2 AXIALIMAGE-
INTERSPHINTERICFISTULAONTHE LEFT
66
5 CORONALIMAGESHOWINGINTERSPHINCTERICFI
STULAWITH AMEDIALRAMIFICATION
TOTHERIGHT SIDE
66
6 T2 AXIAL IMAGE SHOWING
FISTULA IN THEINTERSPHINCTERIC
66
7 T2 AXIAL IMAGE SHOWING
FISTULA IN THEINTERSPHINCTERIC
67
8 T2 CORONAL IMAGE SHOWING
RIGHTEXTRASPHINTERIC FISTULA
67
9 T2 SPAIR IMAGE SHOWINGMEDIALRAMIFICATIONOFTHE RIGHTPERIANALFISTULA
67
10 T2 CORONALIMAGESHOWING
TRANSPHINTERICFISTULA WITH
68
11 T2CORONALIMAGESHOWING
PARARECTALCOLLECTIONABOVETHESUPRALEV
ATORPLANEON THE LEFT
68
XI
12 T2 CORONAL IMAGE SHOWING A BLIND ENDING
LATERAL RAMIFICATION OF THE FISTULA ON
THE LEFT SIDE
68
13 T2 CORONAL
IMAGEINTERSPHINCTE
SHOWING RIGHT
69
XII
ABSTRACT
Perianal fistulization is an uncommon but important condition of the gastrointestinal
tract that causes substantial morbidity. Perianal fistulas occur in approximately 10 of
100,000 persons, with a twofold to fourfold male predominance. Although anal
fistulas were known to Hippocrates and have been described throughout the centuries,
they began to receive special attention in the 19th century. In 1835, Frederick Salmon
founded the Benevolent Dispensary for the Relief of the Poor Afflicted with Fistula,
Piles, and Other Diseases of the Rectum and Lower Intestines—the now world famous
St Mark’s Hospital—in London. Much of our understanding of perianal fistulas comes
from the work of surgeons at St Mark’s Hospital: Salmon, who operated on Charles
Dickens; Goodsall, who described the course of fistulous tracks from the skin to the
anus ; and Parks, whose classification of fistulas in relation to anal anatomy is widely
used in surgical practice .Complex perianal disease is an extremely debilitating
condition for the patient which leads to significant impingement on quality of life. The
accurate identification of anatomical areas of involvement and subsequent appropriate
management is crucial to achieving a successful outcome when treating anal fistulae.
Magnetic resonance imaging (MRI) has become a powerful tool in the evaluation of
anal anatomy. In patients with complex disease MRI is an important adjunct in
delineating disease location and extent, its relationship to sphincter muscles, and in
planning management. Knowledge of pelvic anatomy and associated disease processes
is essential to radiologists and surgeons involved in the management of anorectal
fistulae.On going technological advances continue to contribute to significant
improvements in the images obtained during MR imaging. MRI allows the
classification of fistulous tracts and the identification of underlying infection. It directs
XIV
the ensuing surgical management reducing the incidence of recurrent disease. This
may result in the need for repeated anorectal surgeries with the attendant risk for
incontinence. The purpose of the study is to evaluate the role of Magnetic Resonance
Imaging in Accurately detecting and classification of perianal fistulae
KEY WORDS : Perianal fistulization, Perianal fistulas, St Mark's hospital, Goodsall,
Park's, Magnetic Resonance Imaging
XV
INTRODUCTION
Anal fistula is a common peri-anal surgical problem with which the patient
presents the clinician. A fistula-in-ano is an abnormal hollow tract or cavity that
is lined with granulation tissue and that connects a primary opening inside the
anal canal to a secondary opening in the perianal skin. It is a common peri-anal
surgical problem with which the patient presents the clinician. In around ninety
percent of cases the perianal fistulas are as aresult of secondary to impaired
drainage of the anal glands, according to the “cryptoglandular hypothesis”1
As such, the vast majority of these infections are acute and significant
majority is a contributory to chronic, low-grade infections.2
Infection and anal gland drainage obstruction may lead to an acute
perianal abscess. Some abscesses may resolve spontaneously via internal
drainage into the anal canal, whereas others may require surgical incision and
drainage 3-5 Abscesses that are inadequately or incompletely drained will persist
and may ultimately seek additional drainage pathways through the intersphincteric
space or across the sphincter complex and, in the process, create fistulous tracts.
3-5
Most of these anal fistulae are easy to diagnose with a good source of
light, a proctoscope and digital rectal examination. Despite this establishing a
complete cure of these anal fistulae is very problematic for these two reasons.
First cause being the affection of the disease with respect to the site. Secondly,
the significant percentage of these diseases persists or
~ 1 ~
resumes when the correct type of surgery is not adopted or when
postoperative care is insufficient, or intra-operative if the extensions are lost or
unnoticed.2,3
Also anal fistula needs to differentiated from the following processes,
which do not communicate with the anal canal like the hidradenitis
suppurative, infected inclusion cysts
,pilonidal disease, bartholin gland abscess in females5-7.
The state of the spectrum requires the importance of finding the most
common cause and therefore9-11 a better understanding of the targeted and
specialized management of the condition. In today's scenario where time is money
and litigation is a recalling rule. Better handling of a fistula would be through the
images to see the possible pathways and the branching followed by definitive
surgery.
MR Fistula is the best imaging mode when it comes to soft tissue, especially
the perianal region because it can help identify the presence of abscesses and
extensions that would otherwise be lost during surgery and thus prevent
recurrences.12-15
In view of the above said we did a study “MAGNETIC RESONANCE
IMAGING EVALUATION OF PERIANAL FISTULAS” with the aim to
correlate the MRI findings with clinical examination and classify them.
~ 2 ~
OBJECTIVES
1. The aim and objectives of the present study were as follows:-
2. To Describe and classify perianal fistulae on MRI
3. To determine the MRI sequence most efficient to determine the type of
perianal fistulae and to identify the internal opening.
4. To correlate the MRI findings with clinical examination.
5. To correlate the MRI findings with surgical findings and hence accuracy of
MRI in evaluation of perianal fistulae.
~ 3 ~
REVIEW LITERATURE
Historical aspects of the anorectal fistulas
Anorectal fistulas have been a disease of fascination even in the past ,history
dates back to though era of Hippocrates who used horsehair as a seton to treat
anal fistulas .16
In 1376, the English surgeon John Arderne is said to have written a treatises on
perinal diseases in which he has described fistulotomy and seton use. 17
These diseases affected everyone equally even the great Louis XIV emperor of the
18th century was not spared.18
The late 19th and early 20th centuries saw advances in the theories of perinal
fistulas and the treatment of perinal fistulas with contributions of the renowned
scholars like Goodsall and Miles, Milligan and Morgan, Thompson, and
Lockhart-Mummery, and 1976, Park who refined the classification system of the
disease.19
EPIDEMIOLOGY
Sainio et al in their study that was spread over a ten year old period stated that
anal fistulas affected 510,000 people, 20 The mean incidence of fistulas per
100,000 of the general population was established at 8.6, i.e. 12.3% for males, and
5.6% for females.
~ 4 ~
Nelson et al. found in their meta-analysis that 20,000–25,000 fistulas were treated
annually in the USA21Anal fistula has its maximum incidence between the third
and fifth decades. Men are affected two to four times more commonly 22 and in
the study, all the patients younger than 15 years of age were male 21
MRI TECHNIQUE22,23
Magnetic resonance spectroscopy allows the non-invasive measurement of
selected biological compounds in vivo .Feasibility was first demonstrated in
humans in the mid-1980s. Since that time, much experience has been
accumulated with the use of Magnetic resonance spectroscopy in both research
and clinical applications. Proton spectroscopy has been recognized as a safe and
noninvasive diagnostic method that, coupled with magnetic resonance imaging
techniques, allows for the correlation of anatomical and physiological changes in
the body.
Pre-processing24
An MR signal has to go through a number of pre-processing steps in order
to be usable. Most of those steps increase the quality of the final spectrum and
others take into account some of the technicalities of the acquisition.
Apodization is a process that consists in convolving the free induction decay with
a decreasing exponential. It emphasizes the initial part of the signal, where the
signal-to-noise ratio is high and minimizes the end part, where the decay is
substantial. Doing this increases the quality of the resulting spectrum but at the
expense of enlarging the width of the peaks24
~ 5 ~
MRI has a high intrinsic contrast resolution with an excellent demonstration of the
anal sphincter
and pelvic floor anatomy as well as identification of tracts and abscesses.The
technique has established itself as a reliable technique for the imaging of
perianal fistula25,26 T2-weighted sequences and a fat suppressed sequence are
mainstay. A gadolinium enhanced T1-weighted sequence is very helpful for
differentiating between fluid and granulation tissue, important in abscesses .First,
a sequence in the sagittal plane is performed. The transverse and coronal
sequences must be aligned with the anal canal at the sagittal sequence.
~ 6 ~
There are two types of coils that can be used, the endoanal coil and phased-array
external coils. The latter is far more widely available and most experience concerns
this coil. Advantage of the endoanal coil is the higher spatial resolution, which
might be beneficial in identifying small tracts and internal openings pecially in
patients with Crohn’s disease26 and the wide availability. When both coils are
available an approach where endoluminal magnetic resonance imaging is used for
cryptoglandular fistulas and external MRI in Crohn’s disease seems optimal.
ANATOMY
Knowledge of the anatomy of the anal sphincter complex and surrounding spaces
is crucial for image interpretation The anal canal extends from the levator ani
muscle cranially to the anal verge caudally and is surrounded by the internal
and external anal sphincters. The internal sphincter is the inferior extension of
the inner circular smooth muscle of the rectum and is primarily responsible for
resting involuntary anal continence27
The external sphincter is composed of striated skeletal muscle, which is contiguous
with both the
levator ani and puborectalis muscles superiorly and is primarily responsible for
voluntary continence. As such, injury to the external sphincter during surgery
can lead to fecal incontinence. The internal and external sphincters are separated
by the intersphincteric.28-30
~ 7 ~
FIGURE 1: ANATOMY OF THE ANAL REGION
~ 8 ~
NORMAL MRI ANATOMY OF THE ANAL SPHINCTER
The function of the anal canal and associated anatomy is to maintain fecal
continence. A basic understanding of the anatomy of the anorectal mechanism is
useful to appreciate the common pathways of disease spread in perianal fistula.
The anal canal represents the terminus of the large intestine and measures
between 2.5 to 5 centimeters in length. Two muscular complexes, the internal
and external sphincters, act in concert to provide the contractile effort needed for
fecal continence, with the internal sphincter providing the majority of the resting
tone. The internal sphincter is essentially a continuation of the circular muscular
wall of the rectum, while the external sphincter is functionally connected via the
puborectalis muscle to the levator ani, which forms much of the muscular pelvic
floor . The interstitial tissue between the two sphincters provides a pathway for the
circumferential and axial spread of disease . Penetration of both sphincters
allows disease to enter the fat filled ischioanal fossa, while violation of the
levator plate permits access between the superficial ischioanal fossa and pelvic
pararectal space .31-32
~ 9 ~
FIGURE 2: NORMAL MRI ANATOMY OF THE ANAL REGION 33
The anal sphincter is composed of several cylindric layers . The innermost layer is
the subepithelium. The next layer is the cylindric internal anal sphincter .which is
relatively hyperintense on magnetic resonance imaging. The hypointense
fibroelastic longitudinal muscle courses through the fat-containing inter-
sphincteric space. The outermost layer is composed of relative hypointense
striated muscle with the external anal sphincter inferiorly and the puborectal muscle
superiorly . The puborectal muscle is part of the levator ani muscle, which also
includes the levator plate .33,34
~ 10 ~
Anal Sphincter Defects and Scar Tissue
An anal sphincter defect commonly is defined as a discontinuity of the muscle
ring or an anatomic defect or is recognized by a hypo-intense deformation on MRI
of the normal pattern of the muscle layer due to replacement of muscle cells by
fibrous tissue (functional defect, scar tissue) With magnetic resonance imaging, it
is possible to distinguish an anal sphincter defect from scarring Although there
are differences in diagnosing a defect from scar tissue, the clinical consequences do
not differ.35
Atrophy of the external anal sphincter is characterized by severe thinning of the
muscle fibers or replacement of muscle fibers by fat.36
MRI Features of fistula
On MR images the difference between fibrosis and active fistula tracts can be
easily made. On T2-weighted images, active fistulas and abscesses, which are
filled with pus and debris, are hyperintense, whereas fibrosis is hypointense.
Also the difference between fluid within a tract (e.g. abscess) and active
inflammation can be seen. On post contrast T1-weighted images fluid is
hypointensewhile granulation tissue enhances leading to high signal intensity. The
external anal sphincter has a relatively hypointense aspect and contrasts very well
with the fat in the ischioanal fossa as well as the intersphincteric space on T2-
weighted images. 37
In complex fistulas and high fistulas, magnetic resonance imaging can therefore be
considered as primary imaging technique in patients suspected for these fistulas.
~ 11 ~
When endoscopic ultrasound is used as initial imaging technique in such
patients, magnetic resonance imaging should be performed when endoscopic
ultrasound in inconclusive (e.g. Cases where the fistula cannot be followed
proximal with endoscopic ultrasound). Magnetic resonance imaging with an
external coil does not need introduction of an endoanal device and patient comfort is
in this respect better than for endoscopic ultrasound and endoanal magnetic
resonance imaging.38
For a broad anatomic overview, unenhanced T1 weighted images are ideal for
anatomically delineating the sphincter complex, levator plate, and ischiorectal fossa.
For evaluation of fistulous tracts, T2 weighted images demonstrate hyperintense
fluid within the tract as contrasted to the hypointense fibrous wall of the
fistula. T2 weighted images help differentiate the boundaries between internal
and external sphincters because sphincters and muscles have low signal
intensity while active tracks and extensions have high signal intensity. On
gadolinium-enhanced fat suppressed T1 weighted images, fistulous tracts and
active granulation tissue demonstrate intense enhancement while any fluid
in the track is hypointense.39-42
Chronic fistulous tracts or scars demonstrate low signal intensity on both T1 and
T2 weighted images. There is lack of early enhancement of chronic fistulous
tracts and scars on gadolinium enhancement images. Abscesses can demonstrate
high T2 signal due to the presence of pus in the central cavity.
~ 12 ~
On contrast enhanced fat suppressed T1 weighted images, abscesses demonstrate
low signal intensity centrally with ring enhancement. On postoperative magnetic
resonance imaging, T1 weighted images demonstrate high signal intensity of
hemorrhage products and can thereby help differentiate hemorrhage from residual
tracks .41-44
FIGURE 3: NORMAL MRI ANATOMY OF THE SPHINCTERS.
~ 13 ~
THE ANATOMICAL PARTS OF THE FISTULA45
A complete fistula has four features of interest, that is
(1) the external opening,
(2) the internal opening,
(3) the main track,
(4) branches or main track extensions.
Goodsall 45 suggested a rule that is not infallible but is of definite help in
ascertaining where to search first for the primary opening. He stated: "All fistulae
with their internal openings behind a line drawn transversely through the center of
the anal, have their internal openings in the middle line behind; and that in cases
in which the external aperture is anterior to this line, the inner opening is
directly opposite the external one.
St. James University hospital classification for MRI. 46
Grade Fistula type
1 Simple linear intersphincteric fistula. The fistulous tract extends from the
skin to the anal canal. There is no ramification within the sphincter complex.
The tract is confined by the external sphincter
2 Intersphincteric fistula with abscess or secondary tract. The fistula is
bounded by the external sphincter. Secondary tracts may be of horseshoe type or
may ramify in the ipsilateral intersphincteric plane.
3 Trans-sphincteric fistula. The fistula pierces through both layers of the
sphincter complex and then arcs down to the skin through the ischioanal fossa.
4 Trans-sphincteric fistula with abscess or secondary tract within the
~ 14 ~
ischioanal fossa. The abscess manifests as an expansion along the primary tract or
in the ischioanal fossa.
5 Supralevator and translevator disease. The fistula extends above the
insertion of the levatorani muscle. A suprasphincteric fistula extends upward in
the intersphincteric plane and over the top of the levatorani muscle to pierce
downward to the ischioanal fossa. Extrasphincteric fistulas reflect extension of
primary pelvic disease down through the levator plate.
FIGURE 4: ST. JAMES UNIVERSITY HOSPITAL CLASSIFICATION FOR
MRI
~ 15 ~
Based on etiology
The following classification reasons are listed in order most frequently:
1. Trauma. External traumas are 10, rarer (2% of cases) and are generally as
well of the result of Fall on an object that can tear or hurt the lower intestine
mucosa, or it may be the result of neglected use of the colon probe end or
enema. perforation of the anorectum from impacted chicken or fish bones, from
externally penetrating trauma (stab or gunshot wounds), 47
The internal source is discussed in factors acting on the cryptic condition.48
2. The possibility of trauma to the rectum can occur during the abdominal
surgeries, especially where pelvic adherence is present. In the past was seen
during the procedures like, pubic prostatectomy one procedure rarely done now .49
3. Other causes of iatrogenic fistulas can occur when hemorrhoidal treatment
by injection of sclerosant is done in the wrong plane and necrosis occurs, these
are considered an the ideal conditions for the formation of blind and fistulas.50
4. Rare tumors are often not site ulcerations and therefore must be considered
as an etiologic factor.51
5. Tuberculosis is another common etiologic factor52
Based On the Position50
Fistulae which are purely anal or rectal are of several varieties and may be
named from their shape and number of openings as follows:
"Complete, · which has an opening into the skin and one into the rectum or
anus.
~ 16 ~
o This may be a simple, straight or slightly tortuous tract,
o complex affair with many communication sinuses, which may have blind
endings or rather elaborate communication passages situated in the subcutaneous
tissue and extend over to the opposite side of the anus.
A blind-internal,· fistula which has an opening into the bowel but no opening on the
skin."complete internal,· fistula which has both of its openings in the bowel.
Fourth, the -horse-shoe shape· or ·complete external- which has both of its
openings in the skin.
Fifth, Colt includes the blind-external" which has a communication with the
skin but none with the bowel.
FIGURE 5 :TYPE OF FISTULA IN RELATION TO ANATOMY
~ 17 ~
The classification system developed by Parks, Gordon, and Hardcastle (generally
known as the Parks classification) is the one most commonly used for fistula-
in-ano. This system (see the image below) defines four types of fistula-in-ano
that result from cryptoglandular infections, as follows 51:
The Parks classification, although adapted to some extent, is still the most widely
used classification of perianal fistulas. This classification was primarily developed
for surgical treatment and is therefore especially important for patients treated
surgically. Principal finding in classification is the course of the tract from the anal
mucosa to the perineal skin, in relation to the most outer, striated muscle layer .
Intersphincteric fistulas (24% of cases of primary cryptoglandular fistulas)
course from the internal opening in the anal canal through the internal sphincter and
the intersphincteric plane to the perineal skin.
A transsphincteric fistula (58%) is a fistula that - in addition to the tract as
described for an intersphincteric fistula - passes from the intersphincteric plane at
varying levels through the
~ 18 ~
outer striated muscle layer (thus external sphincter or puborectal muscle) into
the ischioanal fossa.
Relative rare are extrasphincteric fistulas (less than 1%) where the tract
passes from the perineal skin through the ischioanal fat and the levator plate to
the internal opening in the rectum.
Submucosal fistulas (15%) are not included in the original publication of
fistula classification by Parks as these fistulas where not encountered at that tertiary
referral center.
FIGURE 6 :THE PARKS CLASSIFICATION
~ 19 ~
SYMPTOMATOLOGY 1,-5, 28
The patient first complains of an itching or uncomfortable feeling in the region of
the anus which gradually increases and later develops into a severe throbbing pain.
The area about the buttocks becomes quite painful. 47,50 All of these signs and
symptoms are more or less completely relieved and disappear with the rupture of the
skin and discharging of considerable serosanginous fluid or the discharge through
the rectum47,50 As long as free drainage continues the patient will be
symptom free with the exception of local irritation and some slight discomfort. As
soon as the drainage stops the symptoms will in most cases begin to return
although some may go for months or years without recurrence of symptoms.
47,50
FIGURE 6: EXTERNAL OPENING OF FISTULA DIAGNOSIS 47
The diagnosis of fistulae can usually be made from the history and local observation.
It is usually a easy matter, especially when the fistula is complete.
~ 20 ~
INVESTIGATIONS
Classifications are important because treatment differs between different types of
tracts. Simple submucosal, intersphincteric and also low (1/3 lower part of the
anal sphincter) transsphincteric tracts can be treated with fistulotomy without a
(substantial) impact on continence.
IMAGING TECHNIQUES FISTULOGRAPHY AND CT
Both fistulography and computed tomography scan are now considered obsolete
techniques. Few studies have been performed testing the accuracy of
fistulographyand computed tomography scan, all with disappointing results.
Sensitivity of fistulography is in the study of Weismann et 49
88% and the specificity 100%. The sensitivity of 88% can be explained because in
fistulography, possible extensions might not fill with contrast because of debris
or granulation tissue and the anatomical relations are not visualized because pelvic
floor muscles are not identified. In computed tomography scan, the lack of contrast
resolution prohibits differentiating fistulas from pelvic floor muscles.
Endoanal ultrasound
Endoscopic ultrasound gives a detailed visualization of the anal sphincter
complex50-51. Endoscopic ultrasound is a simple and fast technique and generally
well tolerated by patients. A rotating probe covered with a hard sonolucent cone
filled with water, with a 360º radius and a frequency between 5 and 16 MHz is
introduced in the rectum with the patient lying on the left side or supine position
for women. The probe is then slowly withdrawn so that the sphincter complex
~ 21 ~
can be visualized. On a normal ultrasound, the internal sphincter, intersphincteric
space and external sphincter are visible as concentric circular layers. The internal
sphincter is hypoechoic and 2-3 mm in width.
With three-dimensional endoscopic ultrasound a three-dimensional volume is
obtained which can be used to reconstruct in the coronal and sagittal planes,
which is helpful in identifying the extent of the fistula and the relationship to
surrounding structures. West et al compared in 21 patients with a cryptoglandular
fistula hydrogen peroxide enhanced ultrasound with three- dimensional
reconstruction with endoanal MRI and surgery. Endoscopic ultrasound had an
agreement of 81% with surgery and endoanal MRI and surgery 90%. To our
knowledge, this is the only study that prospectively compared52 hydrogen
peroxide enhanced ultrasound with MRI with a surgical reference standard.
TREATMENT 47,50
The only accepted treatment for fistula today is surgery. The principle underlying
this treatment is to lay the main track open together with all offshoots extending
from it. Then allow the wound to heal by granulation from the bottom and not
permit the epithelium to bridge over until the granulations have grown from the
deepest point of the wound to the surface
The goals in the treatment of an anal fistula are to eliminate the primary fistula
opening, any associated tracts, and any secondary openings without a change in
continence. Most anal fistulae are simple and can be treated using a
~ 22 ~
fistulotomy, which has a low recurrence rate and an acceptable rate of
morbidity. eton for treatment of perianal fistula can be of the cutting or a loose
type. Advancement flap is still considered to be the gold standard of treatment
for a complex anal fistula
FIGURE 7: TREATMENT OPTIONS OF FISTULA
~ 23 ~
LITERATURE SURVEY ON MRI IN PERIANAL FISTULA
Lunniss et al. reported a concordance rate of 86-88% between MRI and surgical
findings T2W images (TSE and fat-suppressed) provide good contrast between
the hyperintense fluid in the tract and the hypointense fibrous wall of the
fistula, while providing good delineation of the layers of the anal sphincter.53
Pushpinder S Khera et al of the 43 patients in our study, eight (18%) were identified
as having a perianal sinus only, with no fistula extending into the anal canal. The
rest of the 35 cases were evaluated for the site of the primary tract and its
ramifications, the presence/absence of external sphincter involvement, and the
location of the internal openings. Three patients had a primary or recurrent perianal
fistula with associated Crohn's disease.Two of these three cases had multiple
fistulae and all three had abscess formation .Of the remaining 32 patients
without Crohn's disease, 24 had a primary fistula and, of these, seven had
previously undergone perianal abscess drainage. Eight patients had undergone
previous fistula surgery and had presented with a recurrence. Out of a total of 44
fistulae in these 35 patients, 14 (33%) were transsphincteric,25 (60%) were
intersphincteric. and three (7%) were extrasphincteric.No suprasphincteric fistula
was encountered in the study. Twenty-seven fistulae (61%) were simple,
whereas 17 (39%) showed complications (abscess formation, branching course,
inflammatory tissue, 54.
Dariusz Waniczek et al evaluated MRI fistulography findings were analyzed and
compared with intraoperative conditions in 14 patients (11 men and 3 women)
diagnosed in the years 2005– 2009. Eight patients had recurrent fistulas and 6
~ 24 ~
had primary fistulas. Imaging was performed with a GE SIGNA LX HS scanner
with a 1.5-Tesla field strength and a dedicated surface coil placed at the level of
hip joints. Contrast agent was a gadolinium-based solution. Intraoperative findings
were consistent with radiological descriptions of 13 MRI fistulographies. Only in
one case, according to surgery findings, it was a transsphincteric fistula with
an abscess in the ischioanal fossa, with an orifice in the posterior crypt; the
radiologist described it as a transsphincteric, internal blind fistula.54
Buchanan et al. 55 in their study showed that MR increases the accuracy of
diagnosis by 10% in comparison to EAUS. Additionally, there was a threefold
decrease in recurrence rate after surgical interventions based on appropriate
diagnostics with the use of MR only.
Maier et al. 56showed a statistically higher efficiency in the detection of
perianal fistulas and abscesses in 39 patients with the use of magnetic resonance
(84% sensitivity) as compared to endosonography (60% sensitivity). False-positive
results were present in 6 patients (15%) examined with MR and in 10 (26%)
examined with endosonography.
Beets-Tan et al57 assessed the usefulness of the method by comparing the
results of MRI in patients before surgery with intraoperative findings. They
proved that its sensitivity and specificity for fistulous canal detection amounted to
100% and 86%, respectively. For a horseshoe fistula this was 100% and 100%, and
for internal openings – 96% and 90%.
Mullen et al. 58 showed retrospective analysis of all patients with Anorectal
fistulas with MRI assessment on 40 patients with primary pathologies like
~ 25 ~
perianal sepsis in 20 (50%), Crohn’s disease in 11 (27.5%), primary Anorectal
fistulas in 6 (15%) and others in 3 (7.5%) patients found that MRI established
the fistula anatomy and guided further surgery in 47.1%, correlated with EUA
findings in 38.2% and excluded a suspected fistula in 14.7% of these.
Uttam George 59concluded that MRI exquisitely depicts the perianal anatomy
and shows the fistulous tracks and their associated ramifications and abscesses.
It thus provides an excellent preoperative understanding of the disease, enabling
selection of the most appropriate surgical treatment and therefore minimizing all
chances of recurrence.
60 assessed the contribution of various magnetic resonance
imaging (MRI) sequences in determining the type of perianal fistula and in
obtaining critical information for surgical decisions, as well as to define the optimal
combination of sequences for readers with varying levels of experience , which
included 33 MRI examinations in 26 patients with suspected perianal fistula.
And found that for all sequences, there was statistically significant agreement
between readers for fistula classification, internal opening location, and the
presence of sinus tracts, abscess, a horseshoe component, and inflammation.
O Mailley et al41 stated that Adequate understanding of relevant pelvic
anatomy and fistula classification on MRI examinations is essential in providing
proper assessment of perianal fistulas. Evaluation of clinically undetectable disease
has a significant bearing on guiding medical and surgical therapy and can help
minimize recurrence and better predict outcome compared with surgical
exploration
~ 26 ~
Torkzad MR et al 61 stated in their study that they recommend a short period of
fasting (4 h) before imaging. Since most fistulas are located below the pelvic
floor, bowel peristalsis should not be a problem in the majority of cases.
However, in cases where there is suspicion of supralevator extension of the
disease, antiperistaltic agents might prove essential.
Rishi Philip Mathew et al 62at the of Radio-Diagnosis, Father Muller Medical
College found that The most common age group to be affected was the 4th
decade (30%). Out of the total 30 patients, 28 (93%) were males and 2 (7%) were
females. 23 patients had primary fistulas while 3 had undergone previous fistula
surgery and presented with recurrence. 19 patients (73%) had intersphincteric
fistula while 7 patients (27%) had transsphincteric fistula. 3 patients had perianal
abscesses with no evidence of fistula. There was one false positive and one false
negative case. As per our study MRI had a sensitivity and specificity of 96.15% and
75% respectively.
D. Schettini et al 63 their study concluded THAT MR is the best imaging technique
for evaluating perianal fistulas, because it provides an accurate assessment of the
anal canal, anal sphincter complex, and allows detection of any fistula.
~ 27 ~
Ryan B. O 64 in their study found that MRI evaluation of perianal fistulas can be
challenging, and knowledge of relevant pelvic anatomy and fistula classification
remains crucial in the diagnosis. MRI is highly accurate for fistula depiction and,
by providing an accurate assessment of disease status and extension can help
surgical planning to minimize recurrence and detect clinically unapparent
disease.
Naglaa Daabis 65 in their study found that MRI is a useful procedure for successful
management of peri-anal fistula by correct assessment of the extent of disease
and relationship to sphincter complex. Also it helps in identification of secondary
extensions, particularly horseshoe tracts and abscesses resulting in complete
evaluation and highest possible diagnostic accuracy aiding successful surgical
interventions, aiming to reduce complications and recurrences.
R. BaZ 66 in their study found that MRI has become the method of choice for
evaluating perianal
fistulae due to its ability to display the anatomy of the sphincter muscles
orthogonally, with good contrast resolution.
J A Spencer et al 67 in their study found that MR imaging correctly allowed our
blinded observers
to predict the surgical anatomy of perianal disease in 37 of the 42 patients
(accuracy, 88%). For detection of the presence and site of an enteric fistulous
~ 28 ~
entry, MR imaging had a sensitivity of 97%, a specificity of 67%, a positive
predictive value of 88%, and a negative predictive value of 89%.
Regina G. H. Beets-Tan et al68 in their study on fifty-six patients with anal
fistulas underwent high-spatial-resolution MR imaging MR imaging provided
important additional information in 12 (21%) of 56 patients. In patients with
Crohn’ disease, the benefit was 40% (six of 15); in patients with recurrent
fistulas, 24% (four of 17); and in patients with primary fistulas, 8% (two of 24).
The difference between patients with or without Crohn’s disease and between
patients with a simple fistula versus the rest was significant (P < .05). The
sensitivity and specificity for detecting fistula tracks were 100% and 86%,
respectively; abscesses, 96% and 97%, respectively; horseshoe fistulas, 100%
and 100%, respectively; and internal openings, 96% and 90%, respectively.
~ 29 ~
METHODOLOGY
SOURCE OF DATA :
The study was a prospective correlative study done on a of 30 patients who met
a predefined inclusion and exclusion criterion and underwent MRI examination of
patients for perianal fistula referred from Surgical departments at the SSIMS &
RC, Davangere. The study was done over a period of 2 years from October 2015 to
September 2017.
INCLUSION CRITERIA:
All patients aged 18 to 80 referred with clinically diagnosis of perianal fistula.
EXCLUSION CRITERIA:
MRI technically inadequate for assessment
Operative details not available.
Patients with prior history of surgery in the anorectal region are excluded.
METHOD OF COLLECTION OF DATA:
All pelvic MRI scans were done in 1.5 Tesla G.E MRI scanner in SSIMS & RC,
Davangere.
~ 30 ~
The following sequences were obtained in both the coronal and axial planes:
thin slice, high resolution T1-weighted (W) spin echo; T2-weighted turbo spin
echo; short tau inversion recovery (STIR); contrast enhanced T1-weighted
images and diffusion weighted images.
All patients underwent surgery as a primary treatment modality and
intraoperative details of the fistula were recorded.
MRI findings were compared with intraoperative records, which were
considered as gold standard in treatment.
Different sequences and their combination were analyzed for best
determination of the fistula.
~ 31 ~
SAMPLE SIZE OF ESTIMATION
The study was a prospective correlative study done on a of 30 patients who met
a predefined inclusion and exclusion criterion and underwent MRI examination of
patients for perianal fistula referred from Surgical departments at the SSIMS &
RC, Davangere. The study was done over a period of 2 years from October 2015 to
September 2017.
~ 32 ~
RESULTSDEMOGRAPHIC DATA
Age
Age Frequency Percent
0-25 5 14
26-35 16 46
36-45 6 17
46-55 5 14
56-60 2 6
>60years 1 3
35 100
TABLE 1 : AGE
GRAPH 1 : AGE
The mean age on the present study was 34(SD+) 2.3 years. The youngest case was
24 years and an elder was 62 years of age .most cases were in the age group 26-45
years.
Age 18 1614 12 10
8 6 4 2 0
16
56
5
2 1
0-25 26-35 36-45 46-55 56-60 >60years
~ 33 ~
GENDER
Gender Frequency Percent
Female 3 8.3
Male 32 91.7
Total 35 100.0
TABLE 2: GENDER
GRAPH 2: GENDER
In the present study we found that 32 cases 92 % were males as compared to 8 %
females were affected with fistula
GENDER
Female 8%
Male 92%
~ 34 ~
CLINICAL DETAILS
SWELLING Swelling Frequency Percent
No 28 80
Yes 7 20
Total 35 100.0
TABLE 3: SWELLING
GRAPH 3: SWELLING
In the present study and 7 cases were presented with swelling
60 Swelling
50
40
30
20
10
0 NO YES
~ 35 ~
40
35
30
25
20Yes
15
10
5
0
Frequency
DISCHARGE
DISCHARGE Frequency Percent
Yes 35 100.0
TABLE 4: DISCHARGE
DISCHARGE
GRAPH 4 :DISCHARGES
In the present study all 35 cases were presented with discharge
~ 36 ~
MRI FINDINGS
NUMBER OF EXTERNAL OPENINGS MRI
NUMBER OF EXTERNAL OPENINGS Frequency Percent
1 33 94
4 2 6
Total 35 100.0
TABLE 5: NUMBER OF EXTERNAL OPENINGS
GRAPH 5: NUMBER OF EXTERNAL OPENINGS
In the present study on evaluation of the MRI findings we found that in 33 cases
94% had a single opening.
NUMBER OF EXTERNAL OPENINGS 1 EXTERNAL OPENING, 33
35
30
25
20
15
10
50
4 EXTERNAL OPENING, 2
~ 37 ~
INTERSPHINCTERIC FISTULOUS TRACT MRI
Yes 30 60No 5 40Total 35 100
TABLE 6: INTERSPHINCTERIC FISTULOUS TRACT MRI
GRAPH 6: INTERSPHINCTERIC FISTULOUS TRACT MRI
In the present study on evaluation of the MRI findings we found that in 30 cases
Intersphincteric fistulous was seen .
INTERSPHINCTERIC
No 2
INTERSPHINCTERIC
Yes 33
0 5 10 15 20 25 30 35
~ 38 ~
HORSE SHOE SHAPED RAMIFICATION MRI
HORSE SHOE SHAPED RAMIFICATION PERCENT
No 33 91.7
Yes 2 8.3
Total 35 100.0
TABLE 7: HORSE SHOE SHAPED RAMIFICATION MRI
GRAPH 7: HORSE SHOE SHAPED RAMIFICATION MRI
In the present study on evaluation of the MRI findings we found that in 33 cases
Horse shoe shaped ramification was seen.
INTERSPHINCTERIC
No 2
INTERSPHINCTERIC
Yes 33
0 5 10 15 20 25 30 35
~ 39 ~
TRANSPHINCTERIC TRACT MRI
No 31 87Yes 4 13Total 35 100
TABLE 8: TRANSPHINCTERIC TRACT
GRAPH 8: TRANSPHINCTERIC TRACT
In the present study on evaluation of the MRI findings we found Transphincteric
tract in 31cases, 87%
TRANSPHINCTERIC TRACT
30
25
20
15
10 5 0
No, 31
Yes, 4
No Yes
~ 40 ~
Internal opening 15
10
4
2 1 1 1 1
INTERNAL OPENING MRI
INTERNAL OPENING FREQUENCY PERCENT
1 0 CLOCK 1 3
11 0 CLOCK 4 11
12 0 CLOCK 15 43
2 0 CLOCK 2 6
2,3 0 CLOCK 1 3
2,5,6 0 CLOCK 1 3
6,10,11,7 0 CLOCK 1 3
6 0 CLOCK 10 28
TABLE 9 : INTERNAL OPENING
GRAPH 9 : INTERNAL OPENING
In the present study on evaluation of the MRI findings the above table and graph
show the level of internal openings.
CLOC CLOC CLOC CLOC CLOC CLOCK 0 CLOCK
~ 41 ~
External opening MRI
SINGLE 34 97MULTIPLE 1 3
TABLE 10: EXTERNAL OPENING
GRAPH 10: EXTERNAL OPENING
In the present study on evaluation of the MRI findings we found that in 34 cases a
single opening was seen. in 1 case multiple openings (two openings) were seen
representation was seen , on the same side
External opening
34 35
30
25
20
15
10
51
0
single
multiple
~ 42 ~
NUMBER OF INTERNAL FISTULA TRACTS - MRI
TRACTS FREQUENCY PERCENT1 tract 29 80.2
2 tract 3 9.9
3 tract 2 6.6
4 tract 1 3.3
TABLE 11: NUMBER OF INTERNAL FISTULA TRACTS
GRAPH 11: NUMBER OF INTERNAL FISTULA TRACTS
In the present study on evaluation of the MRI findings we found that in 29cases a
single opening was seen.
30
25
20
15
29 10
5
3 2 1 0
1 tract 2 tract 3 tract 4 tract
~ 43 ~
ST . James's university hospital classification type -MRI
ST . JAMES'S UNIVERSITY
I 16 46II 2 11III 12 34IV 4 6V 1 3Total 35 100
TABLE 12: ST. JAMES'S UNIVERSITY HOSPITAL CLASSIFICATION
TYPE
GRAPH 12: ST. JAMES'S UNIVERSITY HOSPITAL CLASSIFICATION
TYPE
In the present study on evaluation of the MRI findings we found that in 16 cases a
single opening Belonged to Type I and 12 Cases to Type III St. James's university
hospital classification type
4
3
3 St. James's university hospital classification2
23
1
11
5 82 1
0I I II I V
~ 44 ~
SUPRA LEVATOR EXTENSION- MRI FINDINGS
NO 34 98.3
YES 1 1.7
TOTAL 35 100.0
TABLE 13: SUPRA LEVATOR EXTENSION
GRAPH 13: SUPRA LEVATOR EXTENSION
In the present study on evaluation of the MRI findings we found that in 34 cases
there was no Supra-levator extension
70 Supra levator extension 60
50
40
30 34
20
10 1
0
No Yes
~ 45 ~
DISCUSSION
As multiple medical and surgical treatment options exist, imaging plays a critical
role in accurately characterizing perianal fistulas to individualize management
strategy. Differences in the classification scheme have been shown to have an
impact on prediction of prognosis. Imaging options include fistulography,
computed tomography (CT), anal endosonography, and MRI.
MRI classification of perianal fistulae has been significantly associated with
clinical outcome, with MRI grades differing significantly between satisfactory and
unsatisfactory outcomes
MRI evaluation of perianal fistula has also revealed additional diagnostic
information in the preoperative setting, especially for complicated disease
MRI evaluation and classification of perianal fistulae can be standardized with a
high degree of diagnostic accuracy therefore reducing interobserver variability.
COMPARISON OF GENDER DISTRIBUTION
In our study we found that 92 % were males as compared to 8 % females were
affected with fistula .
Rishi Philip Mathew 62 , 28 (93%) were males and 2 (7%) were females.
Study Gender distribution
Marina Garcés-Albir, et al 14 patients (11 men and 3 women)
Sthela Maria Murad-Regadas et al Seventy-four (49%) patients (M: 41, F: 33
our study 32 patients (28 men and 2women)
~ 46 ~
TABLE 24: COMPARISON OF GENDER DISTRIBUTION
COMPARISON OF AGE DISTRIBUTION
The mean age on our study was 43(sd+) 2.3 years. The youngest case was 24
years and eldest was 82 years of age .most cases were in the age group 26-45 years
Study Age distribution
Dariusz Waniczek et al 56 mean age of 47 years (range 21-77),
our study 26-45 years , 34(sd+) 2.3 years
TABLE 25: COMPARISON OF AGE DISTRIBUTION
TYPE OF FISTULA
In our study intersphincteric fistulas (24 cases , 60 %)were the most common
variety as opposed to the study by Marina Garcés-Albir, et al 55low
transsphincteric fistulas were the most frequent type found (33, 47.1%)
followed by high transsphincteric (24, 34.3%) and
intersphincteric fistulas (13, 18.6%).
Marina Garcés-Albir, et al 55in their study showed that the intraoperative
findings were consistent with radiological descriptions of 13 MRI fistulographies.
Only in one case, according to surgery findings, it was a transsphincteric fistula
with an abscess in the ischioanal fossa, with an orifice in the posterior crypt; the
radiologist described it as a transsphincteric, internal blind fistula.
Maier et al. 48 showed a statistically higher efficiency in the detection of
perianal fistulas and
abscesses in 39 patients with the use of magnetic resonance (84% sensitivity) as
~ 47 ~
compared to endosonography (60% sensitivity). False-positive results were present
in 6 patients (15%) examined with MR and in 10 (26%) examined with
endosonography
Beets-Tan et al. 49 assessed the usefulness of the method by comparing the
results of MRI in patients before surgery with intraoperative findings. They
proved that its sensitivity and specificity for fistulous canal detection amounted to
100% and 86%, respectively. For a horseshoe fistula this was 100% and 100%, and
for internal openings – 96% and 90%.
MR imaging findings were correlated with the intraoperative surgical finding IN a
study by Jajoo et al .57 MR imaging shows 7 fistulous patients with side
branching and 16 with abscess cavity which was 100% intraoperatively correlated.
Fifty-six patients out of 60 completely correlated with MRI for primary track
which was clinically significant. MRI had 96% sensitivity and 100% specificity for
primary tract and internal opening an7 100% sensitivity and specificity for abscess
and multiple tracks.
Regina G. H. Beets-Tan et al68 ). The sensitivity and specificity for detecting
fistula tracks were 100% and 86%, respectively; abscesses, 96% and 97%,
respectively; horseshoe fistulas, 100% and 100%, respectively; and internal
openings, 96% and 90%, respectively
Rishi Philip Mathew 62 MRI had a sensitivity and specificity of 96.15% and 75%
respectively. J A Spencer et al 67 in their study found MR imaging had a
sensitivity of 97%, a specificity of 67%, a positive predictive value of 88%, and a
negative predictive value of 89%.
~ 48 ~
CONCLUSION
Perianal fistulae is a clinical entity with significant patient morbidity. While
multiple surgical options exist, recurrence rates and the risk of fecal incontinence
are important considerations in management strategy. MRI provides information
about the fistulae with great anatomic detail with respect to secondary tracks and
abscesses as well as the surrounding pelvic organs. The use of MRI for the
identification and classification of perianal fistulae can provide essential
information that has been shown to have both preoperative and prognostic value.
Preoperative precise localization of the fistulous tract with its internal and external
orifice is the main purpose of the diagnostics in perianal fistulas and, to a large
extent, determines the effectiveness of surgery.
~ 49 ~
SUMMARY
In the present study on evaluation of the MRI findings we found that
In 34 cases a single opening was seen. in 1 case multiple openings (two openings)
were seen representation was seen , on the same side.
Transphincteric tract in 31cases, 87%.
33 cases Horse shoe shaped ramification was seen.
30 cases Intersphincteric fistulous was seen
33 cases 94% had a single opening.
32 cases 92 % were males as compared to 8 % females were affected with fistula
The mean age on the present study was 34(SD+) 2.3 years. The youngest case
was 24 years and an elder was 62 years of age .most cases were in the age group 26-
45 years.
In the present study and 7 cases were presented with swelling
~ 50 ~
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CONSENT
INFORMED CONSENT
I have read and understood the information, it has been read to me and explained in an
understandable language and the language I understand, about the research project
:MAGNETIC RESONANCE IMAGING EVALUATION OF PERIANAL
FISTULAS. I have had the opportunity to ask questions about it and any questions that
I have asked have been answered to my satisfaction. I consent voluntarily to participate
as a participant in this research.
Name of Participant Signature of Participant
Date Day/month/year
If illiterate :
I have witnessed the accurate reading of the consent form to the potential participant,
and the individual has had the opportunity to ask questions. I confirm that the
individual has given consent freely.
Name of witness AND Thumb print of participant Signature of
witness Date __________
Day/month/year Statement by have accurately read out the information sheet to the
potential participant, and to the best of my ability made sure that the participant
understands that various sequences of MRI will be performed for fistulas evaluation. I
confirm that the participant was given an opportunity to ask questions about the study,
and all the questions asked by the participant have been answered correctly and to the
best of my ability. I confirm that the individual has not been coerced into giving
consent, and the consent has been given freely and voluntarily.
A copy of this ICF has been provided to the participant.
Name of Researcher/person taking the consent Signature of
Researcher /person taking the consent Date
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ETHICAL COMMITTEE REPORT
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PRO-FORMA
Name IP No.
Age OP No.
Sex
Case No.
MR no:/Date:
CLINICAL EXAMINATION
SIGNS
Yes/ NO /Explanation
Tenderness
Swelling
Discharge
No of external openings
No of internal openings
Site of internal openings Site of external openings Abscess
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A. Case Proforma
NAME AGE
Clinical Features Mri Features
Intersphincteric Fistulous Tract Horse Shoe Shaped Ramification Transphincteric
Tract,
Internal Opening
External Opening Cm Above The Anal Verge. Tracts
Supra Levator Extension
St. James's University Hospital Classification Type Others
B. Sample Consent Form
I, Dr.Rashmi Aravind Patel. Post graduate in Radiodiagnosis conducting trial for
award of MD degree in Radiodiagnosis.
The topic of the study is:
MAGNETIC RESONANCE IMAGING EVALUATION OF PERIANAL
FISTULAS I have been briefed on the foregoing research being conducted by
Dr.Rashmi Aravind Patel and it has been conveyed to me in my own language .I
have had the opportunity to ask questions about it & all questions that I have
asked have been answered to my satisfaction. I consent voluntarily to
participate as a participant in this research & understand that I have the right to
withdraw from the research at any time without in any way affecting my medical
care.
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Name & Signature Of Participant With The Date And Time ----------------------------
If illiterate: A literate witness must sign ( If possible this person should be
selected by the participant and should have no connection to the research team)
I have read and witnessed the accurate reading of the consent form to the
potential participant and the individual has had the opportunity to ask questions,
I confirm that the individual has given consent freely.
Name of the witness...........................................................
Signature of witness……………….............................……
Date: (d/m/y)……………....................................................
Name & Thumb impression Of Participant With The Date And Time
I have read and witnessed the accurate reading of the consent form to the
potential participant and the individual has had the opportunity to ask questions,
I confirm that the individual has given consent freely. In case of any doubt I have
been asked to contact:
Dr.Rashmi Aravind Patel. Post graduate in Radiodiagnosis
Name of Researcher:……………………………………………………… Signature
of researcher:……………………………………………………
Date :( d/m/y)………………………………………………………………
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MASTER CHART
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D. KEY T0 MASTERCHART
+ - PRESENT
- ABSENT M- MALE
F- FEMALE M- MIDLIE L – FEFT
R – RIGHT
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ANNEXURES
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