1051456
review-article20212021
TAG0010.1177/17562848211051456Therapeutic Advances in GastroenterologyC Bezzio, M Vernero
Therapeutic Advances in Gastroenterology
Review
Insights into the role of gastrointestinal
ultrasound in ulcerative colitis
Cristina Bezzio, Marta Vernero, Davide Giuseppe Ribaldone
Gianpiero Manes and Simone Saibeni
,
Ther Adv Gastroenterol
2021, Vol. 14: 1–7
https://doi.org/10.1177/17562848211051456
DOI: 10.1177/
https://doi.org/10.1177/17562848211051456
17562848211051456
© The Author(s), 2021.
Article reuse guidelines:
sagepub.com/journalspermissions
Abstract: Endoscopic evaluation with histological sampling is the gold standard for the
diagnosis and follow-up of patients with inflammatory bowel disease (IBD), but in the past
few years, gastrointestinal ultrasound (GIUS) has been gaining ground. Due to the transmural
nature of inflammation in Crohn’s disease, GIUS has been mainly applied in this context.
However, GIUS is now being reported to be accurate also for ulcerative colitis (UC). This review
summarizes current knowledge on the use of GIUS in UC, with a focus on clinical practice.
The review covers topics such as GIUS parameters, especially bowel wall thickness; the use of
GIUS in assessing disease extent and in monitoring disease activity; GIUS indexes and scores;
and the combination of GIUS with transperineal ultrasound for a better assessment of the
rectum. With the always growing body of evidence supporting the accuracy of GIUS in UC, this
diagnostic imaging modality can be expected to play a bigger role in disease flare evaluation,
early treatment monitoring, and acute severe disease management.
Keywords: colonoscopy, disease activity, inflammatory bowel disease, ultrasonographic
parameters
Received: 9 July 2021; revised manuscript accepted: 20 September 2021.
Introduction
Ulcerative colitis (UC) is one of the two main
forms of inflammatory bowel disease (IBD).
Together with Crohn’s disease (CD), these
chronic illnesses are characterized by an interplay
between immune system alterations, genetics,
and environmental factors.1 They often require
lifelong therapies and continuous clinical followup, with regular laboratory testing and endoscopic and radiological examinations.2,3
UC-related inflammation typically involves only
the colonic mucosa; the inflammation spreads
continuously from the rectum proximally, to different extents in different patients. According to
the Montreal classification,4 there are three forms
of UC: proctitis (involving only the rectum), leftsided colitis (also involving the sigmoid and
descending colons), and pancolitis or extensive
colitis (extending over the splenic flexure). On
the contrary, in CD, the inflammation is typically
transmural and the whole gastrointestinal tract
can be affected, although in most cases the inflammation is limited to the ileum and colon.5
Until a few years ago, therapeutic success in IBD
was defined as the remission of intestinal symptoms. However, our better comprehension of the
natural history of IBD and, especially, of the
pathophysiological mechanisms underlying the
development and perpetuation of inflammation,
has led to the identification of new therapeutic
targets.6 In turn, the advent of more effective
therapies with different mechanisms of action has
led to modifications in the overall management of
IBD. In particular, more ambitious therapeutic
goals in UC, such as endoscopic and even histological healing, appeared as objectives to obtain
due to their association with overall better outcomes.7 Moreover, these objectives are now
becoming not only the key to achieving deep disease control but also the drivers to monitor
Correspondence to:
Cristina Bezzio
Gastroenterology Unit, Rho
Hospital, ASST Rhodense,
Corso Europa 250, 20017
Rho (MI), Italy.
cribezzio03@yahoo.it
Marta Vernero
Gastroenterology Unit,
Department of Medical
Sciences, University of
Pavia, Pavia, Italy
Davide Giuseppe
Ribaldone
Division of
Gastroenterology,
Department of Medical
Sciences, University of
Turin, Turin, Italy
Gianpiero Manes
Simone Saibeni
Gastroenterology Unit, Rho
Hospital, ASST Rhodense,
Rho, Italy
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(https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission
provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
1
Therapeutic Advances in Gastroenterology 14
initial panoramic view of the abdomen and bowel,
while high frequency is necessary to correctly
assess bowel wall thickness (BWT), stratification,
ulceration, and peristalsis. Although the starting
point is not codified, it is recommended that individual operators perform GIUS with the same
repeated scheme to allow evaluation of the whole
bowel.15
Figure 1. Ulcerative colitis in remission, transverse
section: normal wall thickness of the sigma.
therapeutic responses and to guide therapeutic
changes.3,6,7
Colonoscopy with histological analysis remains
the gold-standard method for the diagnosis and
follow-up of UC patients.2 However, it is an
expensive, invasive diagnostic tool that is generally not well accepted by IBD patients due to the
required bowel preparation before the exam and
to the discomfort or pain during the procedure.8,9
As a consequence, new imaging techniques have
been developed. Among these, gastrointestinal
ultrasound (GIUS) appears to be one of the best
in terms of diagnostic yield, costs, and acceptability.10 GIUS was first applied in CD, due to the
transmural nature of inflammation, and in this
context, it is now an essential instrument for
assessing disease activity, complications (e.g.
abscesses, fistulas, strictures, and bowel enlargement), and therapeutic responses.11–13 The usefulness of GIUS in UC has been supposed for
more than 20 years,14 and only recently has this
usefulness been widely recognized. This narrative
review describes the use of GIUS in the management of patients with UC, with a focus on clinical
practice.
How to perform GIUS
To perform GIUS, no specific preparation is
required, but the patient should fast for 3 h before
the examination. GIUS is performed with the
patient in supine position, with standard abdominal probes (3.5–5 MHz) and high-frequency
probes (7–11 MHz), with gradual compression.
In general, a standard probe is used to get an
2
If colonoscopy is planned on the same day, GIUS
should be performed first to avoid the excessive
presence of air in the bowel from per-endoscopic
insufflation. There is no risk of interference with
GIUS from intravenous contrast medium administered for magnetic resonance imaging or computed tomography exams. Colorectal distension
by enema or anti-spastic medication is not
required.
GIUS parameters for UC
Despite the widespread use of GIUS in UC
patients, no standardized parameters have so far
been identified. Recently, an expert panel assessed
the reliability of GIUS in UC in order to identify
reliable parameters.16 They find, according to
another systematic review,12 that the parameters
to be evaluated should be BWT, parietal blood
flow, Doppler signal, wall layer stratification, and
fatty wrapping.
According to many GIUS studies, BWT is the
most important parameter for defining UC disease activity (Figures 1 and 2) and extent.17–19 Its
performance improves when associated with
detection of a Doppler signal.20,21 Bowel wall
blood flow can also be measured after the intravenous administration of contrast medium, with
similar results to the Doppler signal.22 BWT
should be measured in longitudinal sections, to
ensure reproducibility and interobserver agreement.18,23 As BWT is a quantitative measure, it is
also the most objective parameter, assuming it is
evaluated by a well-trained operator.11,13 Maconi
et al.14 reported that BWT was significantly higher
in patients with active UC than with disease in
remission, and it remained altered in patients
who did not respond to therapy. Many studies
found that 3 mm21,23–26 or 4 mm 14,19,27,28 was a
useful threshold for defining active disease.
However, some studies found differences between
different colonic segments (e.g. >4 mm in the sigmoid colon and >3 mm in the descending, transverse, and right colons18) and between different
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C Bezzio, M Vernero et al.
Figure 2. Ulcerative colitis moderately active: (a) transverse section of the sigma and (b) longitudinal section
of the sigma.
age groups of patients (e.g. 3 mm in adults and
4 mm in children18,29). Nevertheless, BWT has
proven to correlate well with clinical, endoscopic,
and histological activity in many studies.14,19,25,30–32
Parente et al.30 demonstrated a good concordance
between GIUS and both the Baron and Truelove
scores, at the beginning of a flare and after therapy. In some studies, BWT was also found to correlate with C-reactive protein levels.14,25,29
Other parameters that may help in assessing disease activity are the echogenicity of the submucosal layer, mesenteric fibrofatty proliferation,
and loss of colonic haustration.31
Evaluation of disease extent
One of the major limitations of colonoscopy in
patients with severely active UC is the risk of
interruption at the sigmoid colon due to problems
of tolerability and concerns about safety.33
Therefore, it may be difficult to obtain information about the exact extent and features of the disease before starting intravenous steroids or a
rescue therapy. In these cases, GIUS has proven
to be effective in evaluating the disease extent.13,18
A recent meta-analysis of the use of GIUS in
UC34 found good sensitivity and specificity in
detecting active disease (when BWT >3 mm) in
the right and transverse colons. This accuracy
decreased, however, moving toward the rectum,
where the diagnostic potential of GIUS is poor
due to the rectum’s deep position in the pelvis.
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Evaluation and monitoring of
disease activity
GIUS can be used as a surrogate of colonoscopy
in evaluating disease activity.14,30 Monitoring of
therapeutic responses, especially when a patient is
experiencing a disease flare, is crucial for the optimal management of UC patients. Undoubtedly,
frequent colonoscopies to assess treatment
responses are not practical or cost-effective and
are unlikely to be accepted by patients. On the
contrary, GIUS does not require bowel preparation, it is readily available in most hospitals, and it
is well accepted by most patients.8
As shown by the TRUST&UC (TRansabdominal
Ultrasonography of the bowel in Subjects with
IBD To monitor disease activity in Ulcerative
Colitis) study,18 BWT correlates with disease
activity scores both at the beginning of a flare and
after 12 weeks of therapy. This prospective multicentric observational study was conducted on 224
patients with UC (excluding those with proctitis)
with an active disease score ⩾5 on the Short
Clinical Colitis Activity Index (SCCAI). High
BWT (>4 mm in the sigmoid colon and >3 mm
in the other segments) and the Doppler signal
were evaluated at the time of diagnosis and over a
12-week period (at 2, 6, and 12 weeks). Moreover,
additional parameters, including loss of haustration, loss of wall stratification, ascites, lymphadenopathy, and mesenteric fibrofatty proliferation,
were evaluated at each visit. During the study
period, the percentage of patients with high BWT
changed significantly over time: a sigmoid colon
3
Therapeutic Advances in Gastroenterology 14
BWT >4 mm was found in 89.3% of patients at
baseline and in 32.0% at week 12, and a descending colon BWT >3 mm was found in 83.0% of
patients at baseline and in 37.6% at week 12.
Moreover, all additional parameters showed significant reductions from baseline to 12 weeks.
Other interesting findings of this study are the
correlation between SCCAI and BWT and the
fact that BWT at week 2 predicted the response
to treatment.
power Doppler, and lymphadenopathy correlated
with endoscopic disease activity. With this study,
they built a score according to which ultrasound
UC activity is defined by either a BWT >3 mm
plus a power Doppler signal or by BWT >4.43 mm
without the signal. This score had a sensitivity of
0.71 and a specificity of 1.00, and interobserver
agreement was excellent (κ = 0.86). This score
was recently validated under the new name Milan
Ultrasound Criteria.39
The usefulness of GIUS and especially BWT in
monitoring responses to cytapheresis was shown
by Yoshida et al.35 Their study not only demonstrated that GIUS was accurate in monitoring
therapeutic responses, but they also found that a
2.5-mm reduction in BWT was predictive of a
sustained response after 1 week. Indeed, of all the
patients who achieved a BWT reduction of at least
2.5 mm after cytapheresis, 90% were still in clinical remission after 1 year of follow-up versus 40%
of patients with a BWT decrease less than 2.5 mm.
Recently, another new index for grading disease
activity in UC patients was developed and internally validated on 60 patients, using endoscopy as
the reference standard.40 According to this index,
a BWT >2.1 mm discriminates between remission and mild endoscopic activity. Furthermore, a
cutoff of 3.2 mm discriminates between mild and
moderate endoscopic activity and a BWT
>3.9 mm correlates with severe endoscopic activity. The other parameters included in the index
were the presence of a color Doppler signal
(which predicted active disease), lack of haustrations (also predictive of active disease), and fat
wrapping (predictive of severe disease). There
was a strong correlation between the index and
endoscopic disease activity.
Finally, a recent pilot study of 10 patients indicated the potential utility of GIUS in patients
admitted to hospital for severe UC.36 In particular, the study found that a BWT >6 mm in any
colonic segment at admission was associated with
a poor corticosteroid response and with the need
for salvage therapy.
GIUS scores and indexes for UC
With the growing importance of GIUS in UC
monitoring and management, several ultrasonographic scores and indexes have been developed.
Their usefulness, however, is still a matter of
debate, especially regarding their relevance and
feasibility of use in everyday clinical practice.21,37
Here, we summarize the main tools that have
been proposed.
In 2014, Civitelli et al.38 proposed a score for the
pediatric UC population. Ultrasound parameters
such as BWT, increased vascularization, loss of
stratification, and absence of colonic haustration
were compared to the Mayo endoscopic score,
and, at multivariate analysis, all these parameters
strongly correlated with disease activity.
Another UC score is the Humanitas Ultrasound
Criteria, first reported by Allocca et al. in 2018.26
Their prospective study of 53 UC patients found
that BWT >3 mm, hypoechogenicity, a signal on
4
GIUS and transperineal ultrasound
One of the major limitations in using GIUS in
UC is the extreme difficulty in assessing rectal
involvement due to the rectum’s deep position in
the pelvis, not readily reachable by GIUS. One
way to improve the accuracy of GIUS in assessing
UC rectal involvement could be to combine it
with a transperineal evaluation or with the measurement of fecal calprotectin.
On the model of how perianal CD is assessed,41
transperineal ultrasound (TPUS) has been proposed as a new noninvasive tool for evaluating the
rectum in UC. For this purpose, Sagami et al.42
evaluated GIUS combined with TPUS and fecal
calprotectin in 53 patients with active UC requiring
colonoscopy (used as the gold standard). At univariate analysis, BWT <4 mm predicted endoscopic and histological remission with areas under
the curve of 0.90 and 0.89, respectively. This correlation was found to be even better than that
between fecal calprotectin and endoscopic findings. So, the authors suggested that TPUS could be
used in combination with GIUS to assess the whole
colon.
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C Bezzio, M Vernero et al.
TPUS might also be useful in evaluating the
pouch in UC patients who had restorative proctocolectomy with ileo pouch–anal anastomosis
(IPAA) for refractory or complicated disease, but
so far evidence is lacking. Diagnosing and managing pouchitis and identifying surgical failures are
challenging tasks for physicians who care for these
patients.43
Discussion
Evidence supporting the use of GIUS in UC
patients is still limited. However, considering its
noninvasiveness, relatively low costs, lack of need
for bowel preparation, and, especially, the growing evidence that supports its accuracy, we predict that GIUS will become increasingly used in
clinical practice in the coming years. Indeed, even
if scarce data exist about its current use in hospitals, it is known that the lack of GIUS is felt as a
relevant unmet need by physicians managing IBD
patients.44
The most important applications of GIUS appear
to be evaluating the response to therapy and completing the study of the colon in patients with
acute, severe UC scheduled for proctosigmoidoscopy. Further large, prospective studies are
needed to validate the diagnostic accuracy of
GIUS in comparison with colonoscopy and to
identify reliable prognostic parameters.
Finally, GIUS has some limitations. First, the
technique is not standardized and the qualifications of an ‘expert’ GIUS operator remain to be
defined;45 in this regard, scientific societies dedicated to IBD can play an important role in promoting research and educational programs on
GIUS. In practice, other limitations include excessive abdominal fat, low disease activity, and difficulties in evaluating the rectum.45 These difficulties
may be overcome by associating GIUS with a
transperineal evaluation or by measuring biochemical markers such as fecal calprotectin. If this
approach is validated, it would represent another
strength of ultrasonography over colonoscopy.
Conclusion
The role of endoscopy in UC will remain irreplaceable in some cases (e.g. biopsy at diagnosis,
surveillance for dysplasia or colorectal cancer,
and exclusion of cytomegalovirus superinfection
in steroid-refractoriness). Nonetheless, it is likely
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that GIUS will soon demonstrate its undoubted
utility in the management algorithm of UC. In
the era of the ambitious therapeutic targets and
personalized medicine, GIUS will help monitor
UC patients, from the early evaluation of therapeutic responses to changes in therapeutic
strategies.
However, for the role of GIUS to be fully recognized and its use widespread, several needs should
be met. The most important are standardization
of the procedure and definition of the learning
curve. It is also important to determine whether
GIUS or testing of biomarkers (e.g. fecal calprotectin) is better for noninvasive UC monitoring.
Currently, GIUS appears to be superior due to its
ability to assess disease extent and severity.
Acknowledgements
Valerie Matarese provided scientific-linguistic
editing of the manuscript.
Author contributions
CB and SS: study concept and design; acquisition
of data; drafting of the manuscript;
MV acquisition of data; drafting of the
manuscript;
DGR and GM revision of the manuscript for
important intellectual content;
Conflict of interest statement
The authors declared no potential conflicts of
interest with respect to the research, authorship,
and/or publication of this article.
Funding
The authors received no financial support for the
research, authorship, and/or publication of this
article.
ORCID iDs
Davide Giuseppe Ribaldone
org/0000-0002-9421-3087
Simone Saibeni
5677-2534
https://orcid.
https://orcid.org/0000-0001-
References
1. Danese S and Fiocchi C. Ulcerative colitis. N
Engl J Med 2011; 365: 1713–1725.
2. Rahier JF, Magro F, Abreu C, et al. Second
European evidence-based consensus on the
5
Therapeutic Advances in Gastroenterology 14
prevention, diagnosis and management of
opportunistic infections in inflammatory bowel
disease. J Crohns Colitis 2014; 8: 443–468.
3. Magro F, Gionchetti P, Eliakim R, et al.
Third European evidence-based consensus on
diagnosis and management of ulcerative colitis.
Part 1: definitions, diagnosis, extra-intestinal
manifestations, pregnancy, cancer surveillance,
surgery, and ileo-anal pouch disorders. J Crohns
Colitis 2017; 11: 649–670.
14. Maconi G, Ardizzone S, Parente F, et al.
Ultrasonography in the evaluation of extension,
activity, and follow-up of ulcerative colitis. Scand
J Gastroenterol 1999; 34: 1103–1107.
15. Nylund K, MacOni G, Hollerweger A, et al.
EFSUMB recommendations and guidelines for
gastrointestinal ultrasound. Ultraschall Med 2017;
38: e1–e15.
4. Spekhorst LM, Visschedijk MC, Alberts R, et
al. Performance of the Montreal classification
for inflammatory bowel diseases. World J
Gastroenterol 2014; 20: 15374–15381.
16. De Voogd F, Wilkens R, Gecse K, et al. A reliability
study – strong inter-observer agreement of an expert
panel for intestinal ultrasound in ulcerative colitis.
J Crohns Colitis 2021; 15: 1284–1290.
5. Torres J, Mehandru S, Colombel JF, et al.
Crohn’s disease. Lancet 2017; 389: 1741–1755.
17. Strobel D, Goertz RS and Bernatik T.
Diagnostics in inflammatory bowel disease:
ultrasound. World J Gastroenterol 2011; 17:
3192–3197.
6. Turner D, Ricciuto A, Lewis A, et al.
STRIDE-II: an update on the Selecting
Therapeutic Targets in Inflammatory Bowel
Disease (STRIDE) initiative of the International
Organization for the Study of IBD (IOIBD):
determining therapeutic goals for treat-to-target
strategies in IBD. Gastroenterology 2021; 160:
1570–1583.
7. Ungaro R, Colombel JF, Lissoos T, et al. A treatto-target update in ulcerative colitis: a systematic
review. Am J Gastroenterol 2019; 114: 874–883.
8. Buisson A, Gonzalez F, Poullenot F, et al.
Comparative acceptability and perceived clinical
utility of monitoring tools: a nationwide survey
of patients with inflammatory bowel disease.
Inflamm Bowel Dis 2017; 23: 1425–1433.
9. Bezzio C, Schettino M, Manes G, et al.
Tolerability of bowel preparation and
colonoscopy in IBD patients: results from a
prospective, single-center, case–control study.
Crohns Colitis 360 2020; 2: 1–6.
10. Bryant RV, Friedman AB, Wright EK, et al.
Gastrointestinal ultrasound in inflammatory
bowel disease: an underused resource with
potential paradigm-changing application. Gut
2018; 67: 973–985.
11. Sturm A, Maaser C, Calabrese E, et al. ECCOESGAR guideline for diagnostic assessment in
IBD part 2: IBD scores and general principles
and technical aspects. J Crohns Colitis 2019; 13:
273E–284E.
12. Dietrich CF. Significance of abdominal
ultrasound in inflammatory bowel disease. Dig
Dis 2009; 27: 482–493.
13. Bots S, Nylund K, Löwenberg M, et al.
Ultrasound for assessing disease activity in IBD
6
patients: a systematic review of activity scores.
J Crohns Colitis 2018; 12: 920–929.
18. Maaser C, Petersen F, Helwig U, et al. Intestinal
ultrasound for monitoring therapeutic response
in patients with ulcerative colitis: results from the
TRUST&UC study. Gut 2020; 69: 1629–1636.
19. Antonelli E, Giuliano V, Casella G, et al.
Ultrasonographic assessment of colonic wall in
moderate-severe ulcerative colitis: comparison
with endoscopic findings. Dig Liver Dis 2011; 43:
703–706.
20. Smith RL, Taylor KM, Friedman AB,
et al. Systematic review: clinical utility of
gastrointestinal ultrasound in the diagnosis,
assessment and management of patients with
ulcerative colitis. J Crohns Colitis 2020; 14:
465–479.
21. Kucharzik T, Maaser C and MacOni G. Do we
need activity scores or simply clear criteria for
intestinal ultrasound in ulcerative colitis? J Crohns
Colitis 2018; 12: 1383–1384.
22. Girlich C, Schacherer D, Jung EM, et al.
Comparison between quantitative assessment of
bowel wall vascularization by contrast-enhanced
ultrasound and results of histopathological
scoring in ulcerative colitis. Int J Colorectal Dis
2012; 27: 193–198.
23. Pascu M, Roznowski AB, Müller HP, et
al. Clinical relevance of transabdominal
ultrasonography and magnetic resonance imaging
in patients with inflammatory bowel disease of
the terminal ileum and large bowel. Inflamm
Bowel Dis 2004; 10: 373–382.
24. Pradel JA, David XR, Taourel P, et al.
Sonographic assessment of the normal and
abnormal bowel wall in nondiverticular ileitis and
colitis. Abdom Imaging 1997; 22: 167–172.
journals.sagepub.com/home/tag
C Bezzio, M Vernero et al.
25. Arienti V, Campieri M, Boriani L, et al.
Management of severe ulcerative colitis with the
help of high resolution ultrasonography. Am J
Gastroenterol 1996; 91: 2163–2169.
35. Yoshida A, Kobayashi K, Ueno F, et al. Possible
role of early transabdominal ultrasound in
patients undergoing cytapheresis for active
ulcerative colitis. Intern Med 2011; 50: 11–15.
26. Allocca M, Fiorino G, Bonovas S, et al. Accuracy
of Humanitas Ultrasound Criteria in assessing
disease activity and severity in ulcerative colitis:
a prospective study. J Crohns Colitis 2018; 12:
1385–1391.
36. Smith RL, Taylor KM, Friedman AB, et al. Early
assessment with gastrointestinal ultrasound in
patients hospitalised for a flare of ulcerative colitis
and predicting the need for salvage therapy:
a pilot study. Ultrasound Med Biol 2021; 47:
1108–1114.
27. Parente F, Greco S, Molteni M, et al. Role
of early ultrasound in detecting inflammatory
intestinal disorders and identifying their
anatomical location within the bowel. Aliment
Pharmacol Ther 2003; 18: 1009–1016.
28. Bozkurt T, Richter F and Lux G.
Ultrasonography as a primary diagnostic tool in
patients with inflammatory disease and tumors
of the small intestine and large bowel. J Clin
Ultrasound 1994; 22: 85–91.
29. Ruess L, Blask AR, Bulas DI, et al. Inflammatory
bowel disease in children and young adults:
correlation of sonographic and clinical parameters
during treatment. Am J Roentgenol 2000; 175:
79–84.
37. Kucharzik T, Maaser C and Novak K. Are
we ready to use activity scores for intestinal
ultrasound in ulcerative colitis. United European
Gastroenterol J 2021; 9: 423–424.
38. Civitelli F, Di Nardo G, Oliva S, et al.
Ultrasonography of the colon in pediatric ulcerative
colitis: a prospective, blind, comparative study with
colonoscopy. J Pediatr 2014; 165: 78–84.
39. Allocca M, Filippi E, Costantino A, et al. Milan
ultrasound criteria are accurate in assessing
disease activity in ulcerative colitis: external
validation. United European Gastroenterol J 2021;
9: 438–442.
30. Parente F, Molteni M, Marino B, et al. Bowel
ultrasound and mucosal healing in ulcerative
colitis. Dig Dis 2009; 27: 285–290.
40. Bots S, Nylund K, Löwenberg M, et al. Intestinal
ultrasound to assess disease activity in ulcerative
colitis: development of a novel UC-ultrasound
index. J Crohns Colitis 2021; 15: 1264–1271.
31. Bru C, Sans M, Defelitto MM, et al.
Hydrocolonic sonography for evaluating
inflammatory bowel disease. Am J Roentgenol
2001; 177: 99–105.
41. Bezzio C, Bryant RV, Manes G, et al. New
horizons in the imaging of perianal Crohn’s
disease: transperineal ultrasonography. Expert Rev
Gastroenterol Hepatol 2017; 11: 523–530.
32. Sonnenberg A, Erckenbrecht J, Peter P, et al.
Detection of Crohn’s disease by ultrasound.
Gastroenterology 1982; 83: 430–434. https://
pubmed.ncbi.nlm.nih.gov/7084620/ (accessed 25
June 2021).
42. Sagami S, Kobayashi T, Aihara K, et al.
Transperineal ultrasound predicts endoscopic
and histological healing in ulcerative colitis.
Aliment Pharmacol Ther 2020; 51: 1373–1383.
33. Annese V, Daperno M, Rutter MD, et al.
European evidence based consensus for
endoscopy in inflammatory bowel disease.
J Crohns Colitis 2013; 7: 982–1018.
34. Sagami S, Kobayashi T, Miyatani Y, et al.
Accuracy of ultrasound for evaluation of
colorectal segments in patients with inflammatory
bowel diseases: a systematic review and metaanalysis. Clin Gastroenterol Hepatol 2021; 19:
908–921.
journals.sagepub.com/home/tag
43. Outtier A and Ferrante M. Chronic antibioticrefractory pouchitis: management challenges. Clin
Exp Gastroenterol 2021; 14: 277–290.
44. Bezzio C, Imperatore N, Armuzzi A, et al. Unmet
needs of Italian physicians managing patients
with inflammatory bowel disease. Dig Liver Dis
2019; 51: 212–217.
45. Bezzio C and Saibeni S. Gastrointestinal
ultrasound in inflammatory bowel disease: seeing
beyond limits. Dig Liver Dis 2020; 52: 19–20.
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