Incidental pulmonary emboli in stage IV melanoma patients: Prevalence in CT staging examinations and improved detection with vessel reconstructions based on dual energy CT - Fig 3

<p>Pulmonary artery embolus in right upper lobe of a male patient (75y), clearly highlighted in dual energy CT (DECT) vessel reconstruction (a), but not detected on grey scale CT (b). Further pulmonary, subsegmental embolus in the right lower lobe of a male patient (77y), highlighted in red in the DECT vessel reconstruction (c). Retrospectively, a filling defect can be seen in thin-slice (1 mm) reconstructions of the corresponding grey scale CT (d).</p

Platelet counts and international normalized ratio (INR) (measured within 4 weeks before the CT examination).

<p>Platelet counts and international normalized ratio (INR) (measured within 4 weeks before the CT examination).</p

Applied amount of contrast agent (Imeron 300, Bracco, Konstanz, Germany).

<p>Applied amount of contrast agent (Imeron 300, Bracco, Konstanz, Germany).</p

Number of Emboli (z-axis) detected on Dual Energy CT-vessel reconstructions (DECT-VR, bars on the left) and on conventional grey scale CT (bars on the right), subdivided into their anatomical location (yellow: lobar, blue: segmental, red: subsegmental).

<p>Emboli detected on DECT-VR were mainly subsegmentally located.</p

Distribution and clinical features of incidental pulmonary emboli in stage IV melanoma patients.

<p>Distribution and clinical features of incidental pulmonary emboli in stage IV melanoma patients.</p

Potential risk factors for pulmonary emboli (PE).

<p>Potential risk factors for pulmonary emboli (PE).</p

Follow up examination of patient Nr. 4 (see Table 2) 12 months later.

<p>While the CT evaluated in this study showed only a small subsegmental peripheral embolus (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199458#pone.0199458.g003" target="_blank">Fig 3c</a>), the follow up CT demonstrated multiple lobar and central pulmonary emboli.</p

CPMG inter-echo relaxation rate dispersion.

<p>(a) Dependence of CPMG relaxation rate Δ<i>R</i>₂ on the inter-echo time and volume fraction as obtained from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141894#pone.0141894.e025" target="_blank">Eq (20)</a>. (b) Values of <i>τ</i>₁₈₀/<i>τ</i> at the inflection points of the Δ<i>R</i>₂ relaxation rate curve for different regional blood volumes fractions <i>η</i>. For <i>η</i> = 0.8, the inflection point possesses a value of <i>τ</i>₁₈₀/<i>τ</i> = 0.001.</p

Schematic view of peripheral lung tissue and model geometry.

<p>From the left lower pulmonary lobe of the human lungs (a), a lung tissue segment with neighboring alveoli (b) is enlarged: the center alveolus is shown as the cross-section of a rhombic dodecahedron or Wigner-Seitz cell, with thin films as tissue walls (see main text for details and [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141894#pone.0141894.ref015" target="_blank">15</a>]). (c) Schematic cross section of a single alveolus in spherical form with alveolar radius <i>R</i>_A, radius of the dephasing volume <i>R</i> and a set of spherical coordinates (<i>r</i>, <i>θ</i>, <i>ϕ</i>).</p

Sensitivity analysis for varying relaxation rates.

<p>(a) All measured relaxation rates <math><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup></math> for the 3.5h experimental data (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141894#pone.0141894.g005" target="_blank">Fig 5a</a>) were varied within different ranges <math><mrow><mi>δ</mi><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup></mrow></math> with <math><mrow><mo>∀</mo><mi>i</mi>:<mi>δ</mi><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup><mo>/</mo><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup><mo>=</mo>const</mrow></math>. For multiple sets of such variations, the average of the resulting difference to and in proportion of the initially obtained radius <i>R</i>_A is negligible for relative ranges < 0.01. (b) Scatter plot of the resulting radii vs. deviations for the example <math><mrow><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mn>10</mn><mo>)</mo></mrow></msubsup><mo>=</mo><msub><mi>R</mi><mn>2</mn></msub><mrow><mo>(</mo><msub><mi>τ</mi><mn>180</mn></msub><mo>=</mo><mn>17</mn>ms<mo>)</mo></mrow></mrow></math> for different strengths of variation; all other <math><msubsup><mi>R</mi><mn>2</mn><mrow><mo>(</mo><mi>i</mi><mo>)</mo></mrow></msubsup></math> values were also varied within their respective error ranges as in (a).</p