Reviewer's report
Title:The role of MR imaging in detection of hepatic iron overload in patients
with cirrhosis of different origins.
Version: 1Date:28 September 2009
Reviewer: Vincenzo Positano
Reviewer's report:
The authors apply the signal/ratio technique for evaluation of liver iron overload
in patients with cirrhosis. The paper is generally reasonably well written and
conclusions adequately supported by the data. Seems that the main novelty in
the paper is the feasibility of the signal/ratio technique in cirrhotic patients. This
point should be stated more clearly.
Signal/ratio technique is a well established technique (Gandon, Lancet 2004) and
a good correlation with quantitative iron content was demonstrated. However,
this technique today is almost completely overcome by quantitative techniques,
consisting of the direct calculation of T2 or T2* by fitting an appropriate decay
model to the average signal intensity at various echo times ( St Pierre Blood
2005, Wood Blood 2005, Anderson EHJ 2001, Positano MRI 2009, etc).
Calibration curves were evaluated for quantitative iron overload assessment for
these multiecho SE or GRE approaches and allows direct conversion of T2 or
T2* in quantitative iron content.
Authors should acknowledge this limitation in the discussion. Reference to
multi-echo techniques should be added to the introduction.
In conclusion, the study seems to involve an outdated technique and may be of
limited interest.
Detailed comments:
Major Compulsory Revisions:
Abstract:
Background: Changes in MR signal are an indirect consequence of change of
relaxation times T2 and T2*, that can be directly measured.
Methods: “20 patients were......”. This sentence should be moved in results
sub-section because it represents results of biopsy.
Introduction:
Please report recent results in iron overload assessment by multiecho SE and
GRE sequences for quantitative assessment of T2 and T2* values in liver.
Minor Essential Revisions:
Methods:
How patient were chosen? All patients with cirrhosis? Random sampled? Please
elaborate.
“The MR image analysis of iron overload .. was quantitative”. Really, quantitative
analysis should involve tissue characterization by T2 value measurement. The
proposed method is semi-quantitative.
Results and Discussion
“The live cirrhosis was diagnosed ...”. Off course because you selected only
patients with cirrhosis in the methods. Simply state “All patients were
classified....”
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Reviewer's report
Title:The role of MR imaging in detection of hepatic iron overload in patients
with cirrhosis of different origins.
Version: 1Date:28 September 2009
Reviewer: Vincenzo Positano
Reviewer's report:
The authors apply the signal/ratio technique for evaluation of liver iron overload
in patients with cirrhosis. The paper is generally reasonably well written and
conclusions adequately supported by the data. Seems that the main novelty in
the paper is the feasibility of the signal/ratio technique in cirrhotic patients. This
point should be stated more clearly.
Signal/ratio technique is a well established technique (Gandon, Lancet 2004) and
a good correlation with quantitative iron content was demonstrated. However,
this technique today is almost completely overcome by quantitative techniques,
consisting of the direct calculation of T2 or T2* by fitting an appropriate decay
model to the average signal intensity at various echo times ( St Pierre Blood
2005, Wood Blood 2005, Anderson EHJ 2001, Positano MRI 2009, etc).
Calibration curves were evaluated for quantitative iron overload assessment for
these multiecho SE or GRE approaches and allows direct conversion of T2 or
T2* in quantitative iron content.
Authors should acknowledge this limitation in the discussion. Reference to
multi-echo techniques should be added to the introduction.
In conclusion, the study seems to involve an outdated technique and may be of
limited interest.
Detailed comments:
Major Compulsory Revisions:
Abstract:
Background: Changes in MR signal are an indirect consequence of change of
relaxation times T2 and T2*, that can be directly measured.
Methods: “20 patients were......”. This sentence should be moved in results
sub-section because it represents results of biopsy.
Introduction:
Please report recent results in iron overload assessment by multiecho SE and
GRE sequences for quantitative assessment of T2 and T2* values in liver.
Minor Essential Revisions:
Methods:
How patient were chosen? All patients with cirrhosis? Random sampled? Please
elaborate.
“The MR image analysis of iron overload .. was quantitative”. Really, quantitative
analysis should involve tissue characterization by T2 value measurement. The
proposed method is semi-quantitative.
Results and Discussion
“The live cirrhosis was diagnosed ...”. Off course because you selected only
patients with cirrhosis in the methods. Simply state “All patients were
classified....”
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Please review this paper.
user
Reviewer's report
Title:The role of MR imaging in detection of hepatic iron overload in patients
with cirrhosis of different origins.
Version: 1Date:28 September 2009
Reviewer: Vincenzo Positano
Reviewer's report:
The authors apply the signal/ratio technique for evaluation of liver iron overload
in patients with cirrhosis. The paper is generally reasonably well written and
conclusions adequately supported by the data. Seems that the main novelty in
the paper is the feasibility of the signal/ratio technique in cirrhotic patients. This
point should be stated more clearly.
Signal/ratio technique is a well established technique (Gandon, Lancet 2004) and
a good correlation with quantitative iron content was demonstrated. However,
this technique today is almost completely overcome by quantitative techniques,
consisting of the direct calculation of T2 or T2* by fitting an appropriate decay
model to the average signal intensity at various echo times ( St Pierre Blood
2005, Wood Blood 2005, Anderson EHJ 2001, Positano MRI 2009, etc).
Calibration curves were evaluated for quantitative iron overload assessment for
these multiecho SE or GRE approaches and allows direct conversion of T2 or
T2* in quantitative iron content.
Authors should acknowledge this limitation in the discussion. Reference to
multi-echo techniques should be added to the introduction.
In conclusion, the study seems to involve an outdated technique and may be of
limited interest.
Detailed comments:
Major Compulsory Revisions:
Abstract:
Background: Changes in MR signal are an indirect consequence of change of
relaxation times T2 and T2*, that can be directly measured.
Methods: “20 patients were......”. This sentence should be moved in results
sub-section because it represents results of biopsy.
Introduction:
Please report recent results in iron overload assessment by multiecho SE and
GRE sequences for quantitative assessment of T2 and T2* values in liver.
Minor Essential Revisions:
Methods:
How patient were chosen? All patients with cirrhosis? Random sampled? Please
elaborate.
“The MR image analysis of iron overload .. was quantitative”. Really, quantitative
analysis should involve tissue characterization by T2 value measurement. The
proposed method is semi-quantitative.
Results and Discussion
“The live cirrhosis was diagnosed ...”. Off course because you selected only
patients with cirrhosis in the methods. Simply state “All patients were
classified....”
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: No, the manuscript does not need to be seen by a
statistician.
assistant