Review for 10.1186/1471-230X-11-43 (2011)

Reviewer's report
Title:Is hepatotropic contrast enhanced MR a more effective method in
differential diagnosis of hemangioma than multi-phase CT and unenhanced MR?
Version: 1Date:19 August 2010
Reviewer: Takamichi Murakami
Reviewer's report:
In this article, the authors tried to find the most effective diagnostic radiological
features enabling the diagnosis of hemangiomas with atypical appearance in
ultrasound (US) on the basis of multi-phase CT, unenhanced-MR and
liver-specific contrast-enhanced MR.
Major Strengths
1. The authors compared BOPTA-MRI with dynamic CT and unenhanced MRI.
Major weakness
2, There were no quantitative analysis nor statistical analysis.
3, This study design was not appropriate. Usefulness of T2-weighted images for
diagnosis of hemangioma is already well known. If the authors would like to
evaluate usefulness of BOPTA-MRI, they should evaluate unenhanced MRI and
BOPTA-MRI (unenhanced MRI plus BOPTA enhanced MRI). By this study
design, they can show whether BOPTA can improve diagnosis of hemangioma or
not.
Major Compulsory Revisions
Abstract
3, Background
“hemangiomas with atypical appearance in ultrasound (US)”. The authors should
clarify what is “atypical appearance”.
4, Materials and Methods.
“Radiological features of lesions were evaluated by three independent
observers.”
Though three independent observers evaluated, why did the authors show only
consensus data in the text?
Introduction
5, The first paragraph. “However, high percentage of hemangiomas are
nonspecific in US [3,4] and therefore it is necessary to introduce diagnostic
procedures based on the use of new organ-specific contrast agents into the
diagnostic algorithm.”
I can’t agree with this. Now, unenhanced and enhanced MRI with Gd-DTPA are
widely used and useful.
6, The second paragraph. “… but reports on radiographic characteristics of
hepatic lesions in MR imaging without and after liver-specific contrast
administration are rarely encountered [5,6].” There are many papers about
radiographic characteristics of hepatic lesions in MR imaging without.
Materials and Methods
7, The first to third paragraphs. “161 consecutive patients with non-specific
hepatic masses observed in US were included in this prospective study……...398
focal liver lesions were evaluated. All lesions were divided into two groups. The
first group (HH group) consisted of 99 hepatic hemangiomas, recognized in 34
patients. 21 patients with HH had isolated ….were recognized in 13 people. The
second group (nonHH group) included 299 focal liver lesions other than
hemangioma: …”
The authors stated that they evaluate 161 consecutive patients with non-specific
hepatic masses. Did all the 99 hepatic lesions in the 161 consecutive patients
population show “hepatic hemangiomas with atypical findings”? Was there no
hemangioma with typical finding?
8, The fourth paragraph. “final diagnosis was based upon the histopathological
examination”. How to get histological materials. Biopsy? Surgical?
9, The fifth paragraph. “In the remaining 61 patients, the final diagnosis was
based upon the clinical and diagnostic imaging follow-up.” What kind of imaging
modalities were employed for the follow up study? When the follow up
examinations were performed? What kind of imaging findings on each modality
were employed for final diagnosis of FNH, hemangioma, and metastases.
10, The sixth to seventh paragraphs. HAP, PVP, EP and DP should be spelled
out because they appear initially. The scan timing of PVP and EP after an
injection of contrast medium should be stated.
11, The eighth paragraph. “Spiral CT and MR images were then interpreted by
three experienced investigators (ES,AS,MS).” The authors didn’t show data of
each observers. Was this a consensus reading? When did they interpret each
imaging modalities? At the time of blind reading, the observers should interpret
each imaging modalities at least two week intervals to decrease memory bias.
12, The third paragraph from the end of Materials and Methods.
“Statistical analysis concerning characterization of hemangiomas …. has been
performed with Statistica 8 (StatSoft Inc., Tulsa, OK, USA) and #2 test.Stastical
analysis.” As this study compared each imaging modality in the same population,
the authors should employed McNemar test, but not #2 test. Bonferroni
compensation should also be performed because this is multiple comparison
study.
There were no data of p value in the text. Did the authors perform statistical
analysis?
Results
13, The first to the second paragraphs.
“Patient group consisted of 95 women and 66 men in the age of 18-79 years. The
diameter of foci ranged from 6 mm to 125 mm (median 21 mm). According to the
mean foci diameter, all lesions were divided into two groups: small lesions
(<2cm) - 199 foci and large lesions (#2cm) - 199 foci. In the HH-group, 40 foci of
cavernous hemagioma were large lesions and the rest of 59 tumors were small
lesions.”
Who made this standard reference? Study coordinator? Who was Study
coordinator?
The explanation how to made the standard reference should be stated in The
Materials and Methods.
14, The fourth paragraph. “The type of enhancement in consecutive phases was
similar in both CT and MR studies.” Was it similar or completely same?
Discussion
15, The first and second paragraph “Liver hemangioma ….(fig.10).” should be
deleted because they were already reported in the previous papers. Figs. 8-10
should also be deleted.
16, The Discussion is too long and tediously. The authors just introduced
previous papers’ data. Usefulness of T2-weigthed images for diagnosis of
hemangioma is already well known.
17, The fourth paragraph from the end of Discussion.
“Main restrictions of this study are lack of quantitative analysis of focal liver
lesions signal intensity as described by other authors [37] due to a high
occurrence of small foci and no incidence of giant hemangiomas (> 8cm) in
which secondary changes like hemorrhage or hyalinization are more frequent
[38].”
This can’t be a reason to justify lack of quantitative analysis. ROI can be placed
on small lesion by magnifying images.
18, The third to the first paragraphs from the end of Discussion.
In BOPTA-MRI, we usually obtain both unenhanced images and enhanced
images.
Even though T2-weighted imaging is usually useful for diagnosis of hemangioma,
there are same lesions those are hard to diagnose. In such cases, whether an
addition of BOPTA enhanced images to unenhanced images can improve
diagnostic accuracy of hemangioma or not is important.
Tables
19, The authors should make an effort to reduce the number of Tables. 10
Tables are too much.
Figures
20, Figs. 1,2,3,8,9,and 10 should be deleted. The authors should show
hemangioma with atypical signal intensity or enhancement pattern.
Level of interest: An article of insufficient interest to warrant publication in a
scientific/medical journal
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests.