Table 1.
Summary of Statistically Significant MR Parameters in Predicting and Evaluating Complete Tumor Response of Rectal Cancer After NAT
| First Author (Year) | Method | Statistically Significant MR Parameters |
|---|---|---|
| Zhang4 (2017) | T2WI | ↓MTApost, ↓MTLpost, ↓DTApre, ↓CATVpost, ↑MTARR, ↑MTLRR, ↑MTTRR, ↑CATVRR |
| Palmisano6 (2018) | T2WI | ↓Vpost, ↓Vmid,↑ΔVmid, ↑ΔV |
| Sathyakumar26 (2016) | T2WI, DWI | ↓Vpre, ↑ΔV |
| Lambregts27 (2015), Curvo-Semedo41 (2011) | T2WI, DWI | ↓Vpost, ↑ΔV |
| De Cecco54 (2015) | T2WI, TA | ↓kurtosispre, ↑kurtosismid, |
| Aker55 | T2WI, TA | ↑SDpost, ↑entropypost, ↑skewnesspost |
| Yang56 | T2WI, DWI, TA | ↑ADCpost, ↓uniformity |
| De Felice40 (2017) | DWI | ↑ADCmid |
| Kim32 (2011), Blazic34 (2016), Yang28 (2020) | DWI | ↑ADCpost, ↑ΔADC |
| Intven33 (2013) | DWI | ↓ADCpre, ↑ADCpost, ↑ΔADC |
| Lambrecht36 (2012) | DWI | ↓ADCpre, ↑ADCpost, ↑ΔADC, ↑ΔV |
| Xu8 (2018) | DWI (IVIM) | ↓ADCpre, ↓D (IVIM) pre, ↑fpost, ↑ΔADC, ↑ΔD (IVIM), ↑Δf |
| Lu43 (2017) | DWI (IVIM) | ↑D*pre, ↑fpre, ↑D (IVIM)post, ↑ΔADC, ↑ΔD (IVIM) |
| Zhu44 (2017) | DWI (IVIM, SEM) | ↑ADCpost, ↑αpost, ↑ΔADC,↑Δα |
| Liang37 (2019) | DWI (IVIM, SEM) | ↓ADCpre, ↓DDCpre, ↓D(IVIM) pre |
| Hu39 (2017) | DWI (DKI) | ↑ADCpost, ↑ΔADC, ↓Kpre, ↓Kpost, ↑ΔD(DKI), ↑D(DKI)post, |
| Ciolina49 (2019) | DCE | ↑Ktrans pre, ↑Ve post |
| Tong50 (2015) | DCE | ↑Ktranspre, ↑kep pre, ↑Ve pre |
| Zou52 (2019) | DCE, TA | ↓Ktranspost, ↑Δvariance, ↑Δentropy, ↑Δcorrelation |
Note:“↑”refers to the higher values in complete tumor response of rectal cancer;“↓” refers to the lower values in complete response of rectal cancer.
Abbreviations: V, volume; pre, before neoadjuvant therapy; mid, the middle of neoadjuvant therapy; post, after neoadjuvant therapy; Δ the percentage reduction; CATV, cylindrical approximated tumor volume; CATVRR, cylindrical approximated tumor volume reduction rate; DTA, distance from tumor to anal verge; MTA, maximum tumor area; MTARR, maximum tumor area reduction rate; MTL, maximum tumor length; MTLRR, maximum tumor length reduction rate; MTT, maximum tumor thickness; MTTRR, maximum tumor thickness reduction rate; ADC, apparent diffusion coefficient; IVIM, intravoxel incoherent motion; SEM, stretched exponential model; DDC, distributed diffusion coefficient; D(IVIM), slow diffusion coefficient; D*, fast diffusion coefficient; f, perfusion-related diffusion fraction; D(DKI), diffusion coefficient; K, kurtosis coefficient; DCE, dynamic contrast-enhanced; Ktrans, plasma-to-extravascular volume transfer; Kep, extravascular-to-plasma volume transfer constant; Ve, extravascular extracellular volume fraction per unit of tissue volume; Vp, plasma volume; TA, texture analysis.