Communications n
LetterS to the Editor
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Letters to the Editor
Recent eLetters to the Editor are available at radiology.rsna.org. eLetters that are no longer posted under ‘‘Recent eLetters’’ can be found as a link in the related article or by browsing through past Tables of Contents.
Perfusion CT Vascular Parameters and Microvessel Density From Jacob Sosna, MD Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel 91120 e-mail: [email protected]
Editor: I read with great interest the article by Dr Dighe and colleagues, “Perfusion CT Vascular Parameters Do Not Correlate with Immunohistochemistry Derived Microvessel Denisty in Colorectal Tumors,” which appeared in the August 2013 issue of Radiology (1). There is evidence that neovascularization is an early critical event in primary colorectal tumorigenesis, reaching a maximum level early in the malignant process. Vascular branching counts, an indirect estimate of tumor angiogenic activity, are significantly higher in carcinomas than in adenomas. For colonic tumors, microvascular density, a direct measurement of angiogenic vessels in a solid tumor, is lower in the normal mucosa than in adenomas and is highest in carcinomas (2). These findings have stimulated much interest in the use of intravenous contrast material as an adjunctive technique for improved in vivo characterization of polyps. My colleagues and I have previously shown that there was no significant correlation between the size or malignant differentiation of a colorectal polyp and its enhancement values at computed tomographic (CT) colonography (3). Iodine enhancement at a single time point is less precise then perfusion analysis, and perfusion CT is indeed more reliable for tumor assessment. The lack of correlation of perfusion analysis and microvessel density in the study by Dighe and colleagues as well as the lack of correlation between tu936
mor differentiation and iodine enhancement in our study are concordant. Tumor microvessel density and perfusion analysis may not be simply correlated. Blood vessels are dynamic, and besides vessel density other functional changes may thus influence tissue perfusion. It is suggested that further studies be performed to optimize perfusion analysis for the in vivo characterization of tumor neovascularity. Other nonmicrovessel density immunohistochemistry parameters will probably be more precise. However, this will remain a challenge for the next few years. Disclosures of Conflicts of Interest: No relevant conflicts of interest to disclose.
References 1. Dighe S, Blake H, Jeyadevan N, et al. Perfusion CT vascular parameters do not correlate with immunohistochemically derived microvessel density count in colorectal tumors. Radiology 2013;268(2):400–410. 2. Bossi P, Viale G, Lee AK, Alfano R, Coggi G, Bosari S. Angiogenesis in colorectal tumors: microvessel quantitation in adenomas and carcinomas with clinicopathological correlations. Cancer Res 1995;55(21):5049–5053. 3. Sosna J, Morrin MM, Kruskal JB, Farrell RJ, Nasser I, Raptopoulos V. Colorectal neoplasms: role of intravenous contrast-enhanced CT colonography. Radiology 2003 228(1):152–156.
Split-Bolus Spectral Multidetector CT of the Pancreas: Problem Solving in the Detection of “Isoattenuating” Pancreatic Cancer? From Michele Scialpi, MD,* Irene Piscioli, MD,† Michelle Magli, MD,‡ and Alfredo D’Andrea, MD§ Department of Surgical, Radiological and Odontostomatological Sciences, Complex Structure of Radiology 2, Perugia University, S. Maria della Misericordia Hospital, S. Andrea
radiology.rsna.org n Radiology: Volume 270: Number 3—March 2014
LetterS to the Editor
Note: This copy is for your personal non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, contact us at www.rsna.org/rsnarights.
Letters to the Editor
Recent eLetters to the Editor are available at radiology.rsna.org. eLetters that are no longer posted under ‘‘Recent eLetters’’ can be found as a link in the related article or by browsing through past Tables of Contents.
Perfusion CT Vascular Parameters and Microvessel Density From Jacob Sosna, MD Department of Radiology, Hadassah Hebrew University Medical Center, Jerusalem, Israel 91120 e-mail: [email protected]
Editor: I read with great interest the article by Dr Dighe and colleagues, “Perfusion CT Vascular Parameters Do Not Correlate with Immunohistochemistry Derived Microvessel Denisty in Colorectal Tumors,” which appeared in the August 2013 issue of Radiology (1). There is evidence that neovascularization is an early critical event in primary colorectal tumorigenesis, reaching a maximum level early in the malignant process. Vascular branching counts, an indirect estimate of tumor angiogenic activity, are significantly higher in carcinomas than in adenomas. For colonic tumors, microvascular density, a direct measurement of angiogenic vessels in a solid tumor, is lower in the normal mucosa than in adenomas and is highest in carcinomas (2). These findings have stimulated much interest in the use of intravenous contrast material as an adjunctive technique for improved in vivo characterization of polyps. My colleagues and I have previously shown that there was no significant correlation between the size or malignant differentiation of a colorectal polyp and its enhancement values at computed tomographic (CT) colonography (3). Iodine enhancement at a single time point is less precise then perfusion analysis, and perfusion CT is indeed more reliable for tumor assessment. The lack of correlation of perfusion analysis and microvessel density in the study by Dighe and colleagues as well as the lack of correlation between tu936
mor differentiation and iodine enhancement in our study are concordant. Tumor microvessel density and perfusion analysis may not be simply correlated. Blood vessels are dynamic, and besides vessel density other functional changes may thus influence tissue perfusion. It is suggested that further studies be performed to optimize perfusion analysis for the in vivo characterization of tumor neovascularity. Other nonmicrovessel density immunohistochemistry parameters will probably be more precise. However, this will remain a challenge for the next few years. Disclosures of Conflicts of Interest: No relevant conflicts of interest to disclose.
References 1. Dighe S, Blake H, Jeyadevan N, et al. Perfusion CT vascular parameters do not correlate with immunohistochemically derived microvessel density count in colorectal tumors. Radiology 2013;268(2):400–410. 2. Bossi P, Viale G, Lee AK, Alfano R, Coggi G, Bosari S. Angiogenesis in colorectal tumors: microvessel quantitation in adenomas and carcinomas with clinicopathological correlations. Cancer Res 1995;55(21):5049–5053. 3. Sosna J, Morrin MM, Kruskal JB, Farrell RJ, Nasser I, Raptopoulos V. Colorectal neoplasms: role of intravenous contrast-enhanced CT colonography. Radiology 2003 228(1):152–156.
Split-Bolus Spectral Multidetector CT of the Pancreas: Problem Solving in the Detection of “Isoattenuating” Pancreatic Cancer? From Michele Scialpi, MD,* Irene Piscioli, MD,† Michelle Magli, MD,‡ and Alfredo D’Andrea, MD§ Department of Surgical, Radiological and Odontostomatological Sciences, Complex Structure of Radiology 2, Perugia University, S. Maria della Misericordia Hospital, S. Andrea
radiology.rsna.org n Radiology: Volume 270: Number 3—March 2014
