Keywords
diagnostic value - image-guided percutaneous omental - peritoneal - mesenteric biopsy
- technical success rate
Introduction
The peritoneum is the largest serous membrane in the body and forms anatomic reflections
that give rise to the omentum and mesentery. The peritoneum, omentum, and mesentery
can be affected by a variety of diseases that include both neoplastic and nonneoplastic
lesions.[1] Ovarian and gastrointestinal malignancies are the most common neoplasms that seed
the peritoneum. In a patient with a known malignancy, the presence of an omental or
peritoneal lesion usually indicates metastasis; however, a biopsy is often necessary
to confirm the diagnosis. Cross-sectional imaging, including computed tomography (CT)
or magnetic resonance imaging, is the mainstay of modalities in evaluating these lesions.
Traditionally, open surgical biopsy under general anesthesia has been the gold standard
method, but it entails additional hospitalization expenditure and anesthesia risks.
Diagnostic laparoscopy and biopsy can be performed safely and are often favored, especially
in young, healthy individuals. In cases of clinical and diagnostic uncertainty, image-guided
biopsy of these lesions and tissue sampling represent the best option for the evaluation
of disease pathology.[2]
[3]
[4] Obtaining tissue for genetic and molecular analysis is becoming increasingly essential
for directing cancer therapy and assessing response to treatment. Therefore, tissue
histopathological diagnosis remains extremely important, since potential treatment
options differ significantly for various malignancies and benign diseases.[5]
[6] Percutaneous image-guided biopsy is a minimally invasive, safe, effective, and proven
procedure, which has been applied throughout the body for tissue sampling and can
be done either under ultrasound (US) or CT guidance.[7]
[8]
[9] Image-guided biopsy of omental, peritoneal, and mesenteric lesions can be technically
challenging owing to the variable depth of lesions from the skin surface; proximity
of lesions to vital structures, including vessels, gastrointestinal tract, or solid
organs; and relative mobility of these lesions in the intra-abdominal fat as opposed
to lesions within solid organs.[10]
[11]
[12]
[13] The US has several advantages, including wide availability, portability, lack of
ionizing radiation, relatively short procedure time, real-time visualization of the
biopsy needle and target lesion during the procedure, ability to guide the procedure
in almost any anatomic plane, fewer false-negative biopsies, and fewer false-positive
biopsies.[14]
[15]
[16] However, in deep lesions, as in the case of mesenteric lesions or extremely obese
patients, the US has limitations of lesion visibility due to bowel gases and abdominal
wall fat, and in these cases, CT-guided biopsies can be performed.[17]
[18]
[19]
[20]
[21] The purpose of this study was to assess the technique, technical success rate, and
predictive value of image-guided percutaneous biopsy of omental, peritoneal, and mesenteric
lesions.
Material and Methods
Study Design and Sample Size
The combined prospective and retrospective study was conducted in the Department of
Interventional Radiology, Max Super Specialty Hospital, New Delhi, India, from January
2019 to April 2021. Retrospective data was also obtained. The sample size calculation
was done from the study by Vadvala et al, where the sensitivity of biopsy was 0.955
(95.5%) and prevalence was 0.511 (51.1%).[10] A maximum error of 4% was allowed since the sensitivity was already 95.5%, and an
error of 4% made it 99.5% (100% is the limit). Thus, L = 0.04.
The calculation was based on the following formula:
By substituting the above values, we got a minimum sample size of 202 when an error
of 4% was allowed on either side of the estimate of the sensitivity with a confidence
level of 95%.
Study Population and Intervention
Retrospective data was obtained by retrospective review of the institutional database
to identify patients who underwent percutaneous biopsy of the omentum, peritoneum,
or mesentery guided by CT scan and US between January 2019 and April 2021, which was
done using the keywords “peritoneal,” “omental,” and “mesenteric.” All the histopathological
reports were retrieved and analyzed for those patients whose imaging data were obtained
in the picture archiving and communication system (PACS). All the biopsy procedure
scans were reviewed, and the data required for the study were obtained. For prospective
data, all patients referred to the interventional radiology department for image-guided
peritoneal, omental, or mesenteric biopsy during the study period were included in
the study. Patients not willing to participate in the study (n = 1) and cases lost to follow-up (n = 3) were excluded from the study. Patients in whom imaging data could not be retrieved
in the PACS were also excluded (n = 12).
A total of 235 patients were initially enrolled in the study. 16 patients were excluded
from the study due to various reasons mentioned above. Out of the remaining 219 patients,
207 patients underwent CT-guided biopsies and 12 patients underwent US-guided biopsies.
US-guided biopsies, being real-time procedures, were not evaluated for technical and
diagnostic performance assessment. The final study cohort included 207 patients, including
134 prospective cases and 73 retrospective cases.
Preprocedure checklist pro forma was filled out for all the patients. Complete blood
counts and coagulation profiles were observed. Biopsies were performed after the correction
of coagulation parameters in patients with deranged coagulation profiles—any platelet
count below 80000/μL and prothrombin time with an international normalized ratio more
than 1.4. A partial thromboplastin time value of 23.8 to 37.4 seconds was considered
acceptable for the procedure. Patient medication history was obtained, and those patients
who were on anticoagulants and antiplatelet drugs were advised to stop the medications
for a certain time, as per the standard guidelines (3–5 days). All biopsies were scheduled
as CT-guided procedures. If the initial US identifies the target lesion clearly, the
biopsy is performed under US guidance. The rest of the biopsies were performed under
CT guidance (128-slice CT scanner, Siemens).
All biopsies were performed with a coaxial technique using a 17-gauge coaxial introducer
system and an 18-gauge cutting needle for core specimens (BARD MISSION Disposable
Core Biopsy Instrument Kit). Patients were placed in a CT scanner in the supine position,
and preliminary axial images were acquired to localize the target lesion. Few patients
were turned to the right/left oblique/lateral decubitus position to obtain safe passage
and better lesion targeting. Under aseptic precautions, the 17-gauge coaxial introducer
needle was advanced into the lesion. Repeat scans were performed to confirm the needle
position. Needle adjustments were done until the tip of the needle was centered on
the target lesion. The number of needle adjustments was recorded. Once the coaxial
needle was satisfactorily within the target lesion, the 18-gauge cutting needle was
advanced through the 17-gauge coaxial introducer needle, and 3 to 4 core tissue specimens
were obtained in different trajectories. In a few cases of mesenteric lesions that
were located deep, a safe passage was created using hydrodissection along the needle
tract in the mesentery. Procedure time in minutes was calculated from the time of
acquisition of the preliminary images to the time of acquisition of images after the
procedure. Complications during and postprocedure were recorded.
Technical aspects were described based on the lesion size in long axis/thickness,
short axis, depth of lesion from the skin surface, average time of the procedure,
and number of needle repositionings or adjustments. Technical success is defined as
the completion of the planned biopsy by obtaining core tissue biopsy specimens. Diagnostic
yield of a procedure was determined based on the diagnostic biopsy result of the procedure.
Diagnostic performance was defined in terms of sensitivity, specificity, positive
predictive value (PPV), and negative predictive value (NPV).
Methods of Outcome Measurement
The lesions were considered diagnostic if the report included one of the following
terms: malignant, suspicious, benign, and atypical for neoplastic lesions, or inflammatory,
infective, fibrosis, or normal tissue for nonneoplastic lesions. Unless the sample
was interpreted as nondiagnostic (insufficient/inadequate sample for interpretation),
it was considered diagnostic for this study. The histopathology result obtained from
the biopsy procedure was considered a reference standard, and wherever possible, additional
pathology from surgery was correlated. The biopsy result was considered true-positive
if the initial clinical diagnosis correlated with the histopathology result. A biopsy
result was considered true-negative if either a repeat biopsy or surgery confirmed
a benign or atypical result of the biopsy or if there was no change in lesion size
or disappearance of the lesion on follow-up imaging. The biopsy result was considered
false-negative if, after a benign or atypical finding or inconclusive, repeat percutaneous
biopsy or surgery yields malignant tissue.
Statistical Methods
The data was entered in a Microsoft Excel spreadsheet, and analysis was done using
Statistical Package for Social Sciences (SPSS) version 21. Univariate analysis was
done initially, and the results were presented with the help of tables and text. Descriptive
statistics were used to calculate frequencies of categorical variables, and measures
of central tendency and dispersion were used to describe continuous variables. Calculation
of technical success rate and diagnostic yield was performed for all biopsies as a
group and separately for omental, peritoneal, and mesenteric biopsies. Sensitivity,
specificity, PPV, and NPV were calculated for patients with diagnostic lesions, malignant
and suspicious results classified as positive, and benign and atypical results classified
as negative. Bivariate analyses were done using the chi-square test/Fisher's exact
test. For quantitative variables, the unpaired analysis of variance test or the Kruskal–Wallis
test was used. A p-value of < 0.05 was considered statistically significant.
Results
The mean age of study participants in the study was 56.6 ± 14.6 years. Out of the
207 participants, 93 (44.9%) were above the age of 60 years, followed by 42.5% in
the age range of 41 to 60 years. In the study, 76.3% of participants were male while
23.7% were female. In the study, out of the 207 participants, 81.2% were known cases
of malignancy, and 18.8% were benign with no known malignancy. The biopsy from 207
participants was taken from the omentum, peritoneum, and mesentery in 76.8, 14.5,
and 8.7%, respectively. [Figs. 1] to [3] show CT images of CT-guided biopsies performed from omentum thickening, peritoneal
nodules, and mesenteric lesions, respectively, in our patients. According to biopsy,
75.8% were diagnosed with malignant pathology and 24.2% were diagnosed with benign
pathology. All the biopsy procedure details and complications are summarized in [Table 1]. There was no statistically significant procedure time difference found between
different biopsy sites (p-value 0.91). A statistically significant difference was found in the comparison of
lesion size on the long axis and short axis between different sites (p-value 0.001) and lesion depth from the skin surface (p-value 0.0001). On comparison of several needle repositionings between different biopsy
sites, there was no statistically significant difference (p-value 0.377). The technical success rate was found in 100% of all biopsies. The diagnostic
yield of all the biopsies was 98.06%, and the nondiagnostic rate was 1.93%. No major
complications occurred in the study population, and only 11 patients had minor complications.
Fig. 1 Omental thickening with ascites. A 56-year-old female suspected case of carcinoma
ovary. Computed tomography (CT)-guided biopsy was done from the omental thickening.
(A) CT image showing omental thickening with ascites. The coaxial needle was advanced
(B, C), with the cutting biopsy needle can be seen across the thickened omentum (D). Note can be made of ascites. Histopathology showed metastatic adenocarcinoma with
possible ovarian origin.
Fig. 2 Peritoneal nodule with complication. A 70-year-old male patient with a mass lesion
in the pancreas with elevated CA 19–9 (> 1982 U/mL). Computed tomography (CT)-guided
biopsy was performed from the peritoneal nodule measuring 10 × 6 mm (A). The needle was repositioned three times to get adequate cores in this case (B, C). Postprocedure check CT scan (axial and sagittal views) showing minimal contained
hyperdensity (white arrows) posterior to the nodule—suggestive of hemorrhage (D, E). No progression of hemorrhage noted in follow-up scan. Histopathology showed metastatic
adenocarcinoma.
Fig. 3 Mesenteric lesion. A 40-year-old male patient with abdominal pain and low-grade fever.
CT abdomen showed a lesion at the root of mesentry (A) measuring 3.1 × 2.8 cm (B). The desired path to advance the needle was planned (C). The coaxial biopsy needle was advanced toward the lesion after multiple needle
repositionings (D–F). Coaxial cutting needle through the lesion (G). Biopsy pathology showed necrotizing granulomatous inflammation, suggestive of tuberculosis.
Follow-up contrast CT scan of abdomen (H) after 12 months of antitubercular therapy (ATT) showing complete resolution of the
lesion.
Table 1
Biopsy procedure details and lesion characteristics
|
Frequency
|
|
Omental
|
Peritoneal
|
Mesenteric
|
|
CT guided
|
207
|
|
159/207
|
30/207
|
18/207
|
|
US guided
|
12
|
|
10/12
|
2/12
|
Nil
|
|
Lesion size (in mm)
|
|
Average
|
|
|
|
|
Long axis
|
19.19
|
18.935
|
16.637
|
25.77
|
|
Short axis
|
16.48
|
15.674
|
13.964
|
22.333
|
|
Average depth from skin surface (mm)
|
|
|
40
|
35
|
61
|
|
Average number of needle repositioning
|
|
|
2.82
|
2.56
|
3.16
|
|
Average procedure time (in min)
|
|
|
21.308
|
20.83
|
21.389
|
|
Ascites on CT scan
|
27/207
|
|
22/27
|
4/27
|
1/27
|
|
Complications (minor)
|
11/207
|
|
4/11
|
5/11
|
2/11
|
Abbreviations: CT, computed tomography; US, ultrasound.
In the study, sensitivity, specificity, PPV, and NPV of omental biopsy to diagnose
benign pathology were found to be 83.9, 94.3, 78.8, and 95.9.%, respectively. The
sensitivity, specificity, PPV, and NPV of peritoneal biopsy to diagnose benign pathology
were found to be 50, 82.1, 16.7, and 95.8%, respectively, and that of mesenteric biopsy
was 100, 83.33, 75, and 100%, respectively. The accuracy of omental biopsy, peritoneal
biopsy, and mesenteric biopsy to diagnose malignancy was found to be 92.26, 80, and
88.89%, respectively. A statistically significant difference was found between the
initial diagnosis and the diagnosis made by all biopsies. [Table 2] shows the comparison of total biopsies (omental, peritoneal, and mesenteric biopsies)
with final histology. The overall accuracy and predictive values of all the biopsies
to diagnose pathology are shown in [Table 3]. The overall sensitivity, specificity, PPV, and NPV of all biopsies to diagnose
pathology were found to be 84.62, 91.46, 70.21, and 96.15%, respectively, while the
accuracy to detect malignant pathology was 90.15%. [Table 4] summarizes the diagnostic performance of percutaneous biopsies.
Table 2
Comparison of Total biopsies with final diagnosis:
|
Total
|
|
Final diagnosis
|
|
Benign
|
Malignant
|
|
No.
|
%
|
No.
|
%
|
|
Benign
|
33
|
66.00
|
6
|
3.80
|
|
Initial diagnosis
|
Malignancy
|
14
|
34.00
|
150
|
96.20
|
|
Total
|
50
|
100.00
|
157
|
100.00
|
Table 3
Accuracy and predictive values of total biopsies
|
Statistic
|
Value
|
95% CI
|
|
Sensitivity
|
84.62%
|
69.47–94.14%
|
|
Specificity
|
91.46%
|
86.09–95.25%
|
|
Positive likelihood ratio
|
9.91
|
5.90–16.65
|
|
Negative likelihood ratio
|
0.17
|
0.08–0.35
|
|
Disease prevalence (*)
|
19.21%
|
14.03–25.31%
|
|
Positive predictive value (*)
|
70.21%
|
58.39–79.83%
|
|
Negative predictive value (*)
|
96.15%
|
92.28–98.12%
|
|
Accuracy (*)
|
90.15%
|
85.19–93.88%
|
Abbreviation: PPV, positive predictive value; NPV, negative predictive value; CI,
confidence interval.
Table 4
Summary of diagnostic performance of percutaneous biopsies
|
Diagnostic yield
|
Sensitivity
|
Specificity
|
PPV
|
NPV
|
Accuracy
|
|
Overall
|
84.62%
|
91.46%
|
70.21%
|
96.15%
|
90.15%
|
|
Omental
|
83.9%
|
94.3%
|
78.8%
|
95.9%
|
92.26%
|
|
Mesenteric
|
100%
|
88.3%
|
75%
|
100%
|
88.9%
|
|
Peritoneal
|
50%
|
82.14%
|
16.67%
|
95.83%
|
80%
|
Discussion
The peritoneum, omentum, and mesentery can be involved in a variety of neoplastic,
inflammatory, infectious, and traumatic diseases. Patients with ovarian, gastric,
colonic, or pancreatic cancer are termed as having advanced malignancy when peritoneum
involvement is present. In some cases of ovarian cancer, treatment includes neoadjuvant
chemotherapy followed by cytoreductive surgery; therefore, detecting metastases before
treatment is critical for proper clinical care. When the omentum or mesentery is suspected
to be a location of metastasis, a biopsy becomes relevant in establishing a diagnosis
and determining management. In our study, the mean age of study participants was 56.6 ± 14.6
years, and out of the 207 participants, a maximum of 93 (44.9%) patients were above
the age of 60 years, followed by 88 (42.5%) were in the age group of 41 to 60 years.
A similar study was done by Vadvala et al on a total of 186 participants and found
the mean age of the participants was 63.0 ± 13.8 years, male participants were 47.8%,
and female participants were 52.2%. In a similar study done by Iqbal et al[15] on 60 patients to determine the diagnostic value and safety of US-guided percutaneous
biopsy of omental thickening, the mean age of the patients was 46.33 ± 13.81 years
(range: 25–71 years), female preponderance was found to be higher at 40 (66.7%) as
compared with males at 20 (33.3%), like the current study. In our study, a statistically
significantly larger lesion size in the long axis (25.7 ± 9.9 mm), short axis (22.3 ± 8.9 mm),
and lesion depth (6.1 ± 2.0) was found in mesenteric lesions compared with omental
and peritoneal lesions. Vadvala et al[10] also found similar results with larger lesion sizes in the long axis (52.9 ± 33.99 mm),
short axis (35.8 ± 21.6 mm), and lesion depth (70.0 ± 29.3) in mesenteric lesions
compared with omental lesions. Consistent with the study conducted by Vadvala et al,
there was no difference in diagnostic yield obtained by percutaneous biopsy between
omental, peritoneal, and mesenteric groups, suggesting that diagnostic yield is independent
of lesion size and depth of lesion from the skin surface.[10]
In our study, technical success was found to be 100% for all biopsies. Minor complications
occurred in 11 out of 207 patients (5.3%). All the minor complications were self-limiting,
postprocedural hemorrhage that were not clinically significant. Similar to the current
study, Vadvala et al[10] also found that the technical success rate was 99.5% overall, 100% for omental biopsies,
and 98.9% for mesenteric biopsies, and only one CT-guided mesenteric biopsy was deemed
technically unsuccessful. The overall complication rate was also low (2.7%) in this
study.
The present study shows a higher biopsy success rate (100%) compared with the minimally
acceptable success rate (90%) suggested by the “Quality Improvement Guidelines for
Percutaneous Needle Biopsy.”[12] The present study had a complication rate of 5.3%, which is within the acceptable
complication of up to 6% as recommended by the “Quality Improvement Guidelines for
Percutaneous Needle Biopsy.”[16] A recent randomized clinical trial for renal and prostate biopsies using a coaxial
technique by Babaei Jandaghi et al observed not only low complication rates but also
shorter procedure duration, similar to our results.[17]
[18]
In the present study, out of the 207 participants, 168 (81.2%) patients have a history
of a proven malignancy, and 39 (18.8%) were considered benign with no known malignant
disease. The biopsy site was omentum in 159 (76.8%) patients, peritoneum in 30 (14.5%)
patients, and mesentery in 18 (8.7%) patients. A total of 203 patients had a diagnostic
histopathology report: 156 (75.36%) malignant pathology, 47 (22.7%) benign pathology,
and 4 (1.93%) samples were inconclusive/nondiagnostic according to biopsy. In our
study, among the 164 patients with a known primary malignancy and a diagnostic result
on histopathology, 89% (146 patients) had metastatic disease from the known cancer;
in 2.4% (4 patients), the biopsy result yielded second primary cancer ([Fig. 4]). Out of these four patients, in two patients with primary carcinoma breast, the
histopathology report along with immunohistochemistry showed metastatic disease from
possible ovarian malignancy. Both patients underwent surgery after chemotherapy, and
the diagnosis of ovarian malignancy was confirmed on surgical pathology. One patient
had a retroperitoneal sarcoma, in whom the omental biopsy report showed a neuroendocrine
tumor. This patient underwent a DOTONOC scan, which revealed avidity within the omentum,
suggestive of a neuroendocrine tumor. The last patient was a known postoperative case
of carcinoma colon on follow-up, presented with abdominal distension, and contrast-enhanced
CT scan of the abdomen revealed omental thickening and bilateral bulky ovaries. Histopathology,
along with immunohistochemistry, showed metastatic papillary adenocarcinoma deposits
from a possible serous carcinoma of the ovary. The patient was started on chemotherapy
for ovarian malignancy, and follow-up imaging done after 4 months showed significant
resolution of the omental thickening. In our study, out of the 39 patients with no
known cancer or with a known benign disease, new malignancies were detected in 6 patients
(15.3%). The new cancers that were diagnosed include one each of metastatic colonic
adenocarcinoma, metastatic ovarian carcinoma, well-differentiated adenocarcinoma,
metastatic cecal adenocarcinoma, poorly differentiated adenocarcinoma, and pseudomyxoma
peritonei ([Fig. 5]).
Fig. 4 Diagram showing outcomes of the histopathology report in the study population.
Fig. 5 Distribution of biopsy histopathology outcome in patients with known cancer.
The overall nondiagnostic rate was 1.93% (4 out of 207). Follow-up of these four patients
was done. All four were known malignant patients, including carcinoma ovary (2 cases),
operated cases of carcinoma gallbladder, and carcinoma endometrium. Surgery was performed
in both the carcinoma ovary cases, which revealed no malignancy on surgical histopathology.
No increase in omental thickening was noted at 1-year follow-up imaging in the carcinoma
gallbladder patient. Patients with carcinoma endometrium responded well to chemotherapy
at 4-month follow-up imaging, suggesting that the omental thickening was a metastatic
disease. Vadvala et al in their study (80) included 186 image-guided percutaneous
biopsies of omental (n = 95) and mesenteric (n = 91) lesions. Based on the biopsy results, metastatic disease was confirmed in 82
of 114 (44.1%) patients, and a new diagnosis of a second primary tumor was made by
biopsy in 11 of 114 (5.9%) patients. A nonneoplastic tissue diagnosis was obtained
in 21.5% of biopsies. Souza et al[3] found no statistically significant differences between patients with and without
known cancer.
Our study found a statistically significant difference between initial and histopathological
diagnoses from biopsies from individual sites and the total. The sensitivity, specificity,
positive predictive value (PPV), and negative predictive value (NPV) of total biopsies
(combined omental, mesenteric, and peritoneal) for diagnosing pathology were 84.62%,
91.46%, 70.21%, and 96.15%, respectively. For individual biopsy types, the values
were as follows: Omental biopsy: 83.9%, 94.3%, 78.8%, and 95.9%, respectively. Mesenteric
biopsy: 100%, 83.3%, 75%, and 100%, respectively. Peritoneal biopsy: 50%, 82.1%, 16.7%,
and 95.8%, respectively. The accuracy of total biopsies, omental, mesenteric, and
peritoneal biopsies, to diagnose the malignancy was found to be 90.15, 92.26, 88.9,
and 80%, and was found to be statistically significant. Similarly, a study conducted
by Vadvala et al[10] found overall sensitivity of 95.5%, specificity of 100%, NPV of 78.3%, and PPV of
100%. Core biopsies had higher diagnostic yields compared with fine needle aspiration:
98.4% versus 84% overall, 99% versus 88% for omental biopsies, and 97.7% versus 80%
for mesenteric biopsies. Souza et al,[3] in their study, found that the overall diagnostic rate was 89%, with a sensitivity
of 93%, specificity of 86%, and NPV of 50%. Hill et al[14] found the diagnostic accuracy to be 99% (181 patients). Biopsy was positive for
malignancy in 95% of patients with omental caking, 92% with omental nodularity, 80%
with a single omental nodule, and 20% with omental thickening. In this study, both
US- and CT-guided procedures were evaluated together. Yu et al[20] found the accuracy rate of CT-guided percutaneous fine-needle aspiration biopsy
was 95.1%.
The overall sensitivity and specificity in our study were high (84.6 and 91.4%). However,
compared with the previously mentioned studies, these values are relatively on the
lower side. This may be attributed to a larger study population, diagnosis based only
on biopsy specimen, with no additional use of FNA sampling, which was done in most
of the previously mentioned studies. Most of the previous studies included both US-
and CT-guided biopsies for the evaluation of diagnostic value, which was not the case
in our current study, where we evaluated only the percutaneous biopsies performed
exclusively under CT guidance. This might have influenced our results. In our study,
accuracy in diagnosing a malignant disease based on a histopathology report is 90.15%
when compared with the initial clinical diagnosis. However, when we compared the histopathology
diagnosis obtained from biopsy with the final diagnosis (after follow-up imaging or
surgical pathology), there was high diagnostic accuracy (100%), indicating that percutaneous
biopsy reports were highly accurate in diagnosing both benign and malignant diseases.
Conclusion
The study concluded that image-guided percutaneous biopsy of omental, mesenteric,
and peritoneal lesions has a high technical success rate and diagnostic yield irrespective
of lesion size and lesion depth. This implies that image-guided percutaneous biopsy
of the omentum, mesentery, and peritoneum is a less expensive, safe, and effective
method with high diagnostic accuracy to diagnose lesions.
