Additional file 1 of Short-time-window Patlak imaging using a population-based arterial input function and optimized Bayesian penalized likelihood reconstruction: a feasibility study

Additional file 1. Figure S1. The correlation between IDIF and Ao-50 among the 12 patients. There is a significantly high correlation between IDIF and Ao-50 (Y = 113.76 + 97.16x; r = 0.98, p < 0.001)

Additional file 3 of Short-time-window Patlak imaging using a population-based arterial input function and optimized Bayesian penalized likelihood reconstruction: a feasibility study

Additional file 3. Figure S3. Correlations of the Ki-mean between the reference images and the population-based Ki IF images. For both readers, significant strong and positive correlations (all p < 0.001) for Ki-mean were noted between the reference images and Ki-350 (a reader 1, r = 0.91; b reader 2; r = 0.89), Ki-700 (c reader 1, r = 0.94; d reader 2, r = 0.95) and Ki-1000 images (e reader 1, r = 0.95; f reader 2, r = 0.96)

Additional file 4 of Short-time-window Patlak imaging using a population-based arterial input function and optimized Bayesian penalized likelihood reconstruction: a feasibility study

Additional file 4. Figure S4. Correlations of the Ki-volume between the reference images and population-based Ki images. For both readers, significant and positive correlations (all p < 0.001) for Ki-volume were noted between the reference images and Ki-350 (a reader 1, r = 0.84; b reader 2, r = 0.75), Ki-700 (c reader 1, r = 0.82; d reader 2, r = 0.73) and Ki-1000 images (e reader 1, r = 0.87; f reader 2, r = 0.78)

Additional file 2 of Short-time-window Patlak imaging using a population-based arterial input function and optimized Bayesian penalized likelihood reconstruction: a feasibility study

Additional file 2. Figure S2. Correlations of the Ki-max between the reference images and the population-based IF Ki images. For both readers, significant strong and positive correlations (all p < 0.001) for Ki-max were noted between the reference images and Ki-350 (a reader 1, r = 0.93; b reader 2, r = 0.90), Ki-700 (c reader 1, r = 0.94; d reader 2, r = 0.94), and Ki-1000 images (e reader 1, r = 0.95; f reader 2, r = 0.96)

Amide Proton Transfer Imaging of Diffuse Gliomas: Effect of Saturation Pulse Length in Parallel Transmission-Based Technique

<div><p>In this study, we evaluated the dependence of saturation pulse length on APT imaging of diffuse gliomas using a parallel transmission-based technique. Twenty-two patients with diffuse gliomas (9 low-grade gliomas, LGGs, and 13 high-grade gliomas, HGGs) were included in the study. APT imaging was conducted at 3T with a 2-channel parallel transmission scheme using three different saturation pulse lengths (0.5 s, 1.0 s, 2.0 s). The 2D fast spin-echo sequence was used for imaging. Z-spectrum was obtained at 25 frequency offsets from -6 to +6 ppm (step 0.5 ppm). A point-by-point B0 correction was performed with a B0 map. Magnetization transfer ratio (MTR_asym) and ΔMTR_asym (contrast between tumor and normal white matter) at 3.5 ppm were compared among different saturation lengths. A significant increase in MTR_asym (3.5 ppm) of HGG was found when the length of saturation pulse became longer (3.09 ± 0.54% at 0.5 s, 3.83 ± 0.67% at 1 s, 4.12 ± 0.97% at 2 s), but MTR_asym (3.5 ppm) was not different among the saturation lengths in LGG. ΔMTR_asym (3.5 ppm) increased with the length of saturation pulse in both LGG (0.48 ± 0.56% at 0.5 s, 1.28 ± 0.56% at 1 s, 1.88 ± 0.56% at 2 s and HGG (1.72 ± 0.54% at 0.5 s, 2.90 ± 0.49% at 1 s, 3.83 ± 0.88% at 2 s). In both LGG and HGG, APT-weighted contrast was enhanced with the use of longer saturation pulses.</p></div

Amide Proton Transfer Imaging of Diffuse Gliomas: Effect of Saturation Pulse Length in Parallel Transmission-Based Technique - Fig 2

<p>MTR_asym of tumor <b>(A)</b> and NAWM <b>(B)</b> and ΔMTR_asym <b>(C)</b> in LGG. MTR_asym (<b>A</b>) of tumor was decreased with the saturation length in lower frequency range (1–2 ppm), but equivalent at 3.5 ppm. MTR_asym of NAWM (<b>B</b>) is decreased with the saturation length in the entire frequency range. ΔMTR_asym (<b>C</b>) was increased with the saturation length at higher frequency offsets (>2 ppm).</p

Amide Proton Transfer Imaging of Diffuse Gliomas: Effect of Saturation Pulse Length in Parallel Transmission-Based Technique - Fig 1

<p>Z-spectra of LGG <b>(A)</b>, HGG <b>(C)</b>, and corresponding NAWM <b>(B, D)</b>. Z-spectra of tumor was steeper than that of NAWM, presumably because of less MT effect in tumor compared with NAWM. Prolongation of saturation pulses results in larger MT effect and thus wider Z-spectra in both tumor and NAWM.</p

A case of glioblastoma multiforme (Grade IV, HGG).

<p>The APT-weighted signal of the tumor in the left temporal lobe is increased with the saturation length, and the contrast between tumor and normal brain tissue becomes larger at longer saturation pulses.</p

MTR_asym (3.5 ppm) and ΔMTR_asym (3.5 ppm) of LGG and HGG.

<p>No significant differences were observed in MTR_asym (3.5 ppm) among the three saturation lengths in LGG, while MTR_asym (3.5 ppm) with the 1 s and 2 s saturation was significantly higher than that with the 0.5 s saturation in HGG (<b>A</b>). ΔMTR_asym (3.5 ppm) with the 1 s and 2 s saturation length was significantly higher than that with the 0.5 s saturation in LGG, and ΔMTR_asym (3.5ppm) of HGG significantly increased with the saturation length (<b>B</b>). Both MTR_asym (3.5ppm) and ΔMTR_asym (3.5ppm) were significantly higher in HGG than in LGG at any saturation pulse lengths.</p

MTR_asym of tumor and NAWM and ΔMTR_asym in HGG.

<p>MTR_asym of tumor <b>(A)</b> was decreased with the saturation length in lower frequency range (<2 ppm), but was increased at 3.5 ppm. MTR_asym of NAWM <b>(B)</b> was decreased with the saturation length in entire frequency range. ΔMTR_asym <b>(C)</b> was increased with the saturation length at higher frequency (>2 ppm). ΔMTR_asym (3.5 ppm) with the 2 s saturation reached maximum at around 3.5 ppm (specific frequency of amide protons).</p