Differences in Fatty Acid Metabolic Disorder Between Ischemic Myocardium and Doxorubicin-Induced Myocardial Damage: Assessment Using BMIPP Dynamic SPECT with Analysis by the Rutland Method

Differences in Fatty Acid Metabolic Disorder Between Ischemic Myocardium and Doxorubicin-Induced Myocardial Damage: Assessment Using BMIPP Dynamic SPECT with Analysis by the Rutland Method

Kakuya Kitagawa, MD¹, Kan Takeda, MD², Kimimasa Saito, MD³, Shinya Okamoto, MD⁴, Katsutoshi Makino, MD⁴, Hisato Maeda, PhD⁵ and Takashi Ichihara, PhD⁶

¹ Department of Radiology, Matsusaka Central Hospital, Mie, Japan
² Department of Radiology, Mie University, Mie, Japan
³ Department of Internal Medicine, Yamamoto General Hospital, Mie, Japan
⁴ Department of Internal Medicine, Matsusaka Central Hospital, Mie, Japan
⁵ Fujita Health University, Aichi, Japan
⁶ Toshiba Corporation, Tokyo, Japan

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FIGURE 1. (A) Diagram of Rutland equation. Mo(t)/B(t) and ${int}$ B(t)dt/B(t) for each scan time (t) can be calculated from dynamic SPECT data. By plotting Mo(t)/B(t) against ${int}$ B(t)dt/B(t), the linear portion can be identified on curve. Presence of linear portion indicates that there is no significant excretion of BMIPP from myocardium during this period. (B) Determination of duration of linear portion in Rutland equation. Linear correlation coefficients from start of second scan (30 s) to specific scans were calculated and compared. For example, linear correlation coefficient (r) values are 0.9984 and 0.9836 up to 5 and 6 scans, respectively, in this case. Both values are considered to be sufficiently high to indicate a straight line. However, correlation coefficient up to 7 scans rapidly falls to 0.9427. Thus, we determined duration of linear portion to be up to 6 scans in this case. Slope (K value) can then be calculated.

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FIGURE 2. Serial changes in linear correlation coefficients from second scan to specific scans in normal control subjects (A), patients with DxMD (B), and patients with IHD (C). High linear correlation coefficients are maintained up to $~$ 7 scans in normal control subjects, and duration of linear portion is prolonged in DxMD patients and shortened in IHD patients. Individual symbols ( ${circ}$ , ${diamond}$ , ${triangleup}$ , and so forth) represent different patients.

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FIGURE 3. Comparison of duration of linear portion (A) and K value (B). Duration of linear portion is significantly prolonged in DxMD and shortened in IHD. K value is significantly decreased in both DxMD and IHD.

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FIGURE 4. Early and delayed static BMIPP images from patient with DxMD before (A) and after (B) chemotherapy. No regional uptake abnormality is seen on static images. Rutland analysis of dynamic BMIPP SPECT after chemotherapy (D) demonstrates prolonged linear portion and decreased K value compared with that before chemotherapy (C).

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FIGURE 5. (A) Stress and rest ²⁰¹Tl and static BMIPP images of patient with angina pectoris. Coronary angiography shows significant coronary artery stenosis in left anterior descending artery. Redistribution is observed in anterior segment on ²⁰¹Tl images, whereas static BMIPP images show no uptake abnormality in this segment. (B) Rutland analysis of dynamic BMIPP SPECT demonstrates shortened duration of linear correlation with decreased K value.

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FIGURE 6. Schematic diagram of metabolic pathway of BMIPP. ATP = adenosine triphosphate; AMP = adenosine monophosphate; PPi = pyrophosphate; CoA = coenzyme A; PIPA = p-iodophenylacetic acid.

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FIGURE 7. Comparison of typical curves (dashed lines) in Rutland equation among subjects with normal myocardium, DxMD, and IHD. Solid lines indicate linear portion of corresponding curves.