Comparison of ASL and DSC perfusion methods in the evaluation of response to treatment in patients with a history of treatment for malignant brain tumor

OBJECTIVE

Perfusion MRI is of great benefit in the post-treatment evaluation of brain tumors. Interestingly, dynamic susceptibility contrast-enhanced (DSC) perfusion has taken its place in routine examination for this purpose. The use of arterial spin labeling (ASL), a perfusion technique that does not require exogenous contrast material injection, has gained popularity in recent years. The aim of the study was to compare two different perfusion techniques, ASL and DSC, using qualitative and quantitative measurements and to investigate the diagnostic effectiveness of both. The fact that the number of patients is higher than in studies conducted with 3D pseudo-continious ASL (pCASL), the study group is heterogeneous as it consists of patients with both metastases and glial tumors, the use of 3D Turbo Gradient Spin Echo (TGSE), and the inclusion of visual (qualitative) assessment make our study unique.

METHODS

Ninety patients, who were treated for malignant brain tumor, were enrolled in the retrospective study. DSC Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF) and ASL CBF maps of each case were obtained. In qualitative analysis, the lesions of the cases were visually classified as treatment-related changes (TRC) and relapse/residual mass (RRT). In the quantitative analysis, three regions of interest (ROI) measurements were taken from each case. The average of these measurements was compared with the ROI taken from the contralateral white matter and normalized values (n) were obtained. These normalized values were compared across events.

RESULTS

Uncorrected DSC normalized CBV (nCBV), DSC normalized CBF (nCBF) and ASL nCBF values of RRT cases were higher than those of TRC cases (p < 0.001). DSC nCBV values were correlated with DSC nCBF (r: 0.94, p < 0.001) and correlated with ASL nCBF (r: 0.75, p < 0.001). Similarly, ASL nCBF was positively correlated with DSC nCBF (r: 0.79 p < 0.01). When the ROC curve parameters were evaluated, the cut-off values were determined as 1.211 for DSC nCBV (AUC: 0.95, 93% sensitivity, 82% specificity), 0.896 for DSC nCBF (AUC; 0.95, 93% sensitivity, 82% specificity), and 0.829 for ASL nCBF (AUC: 0.84, 78% sensitivity, 75% specificity). For qualitative evaluation (visual evaluation), inter-observer agreement was found to be good for ASL CBF (0.714), good for DSC CBF (0.790), and excellent for DSC CBV (0.822). Intra-observer agreement was also evaluated. For the first observer, good agreement was found in ASL CBF (0.626, 70% sensitive, 93% specific), in DSC CBF (0.713, 76% sensitive, 95% specific), and in DSC CBV (0.755, 87% sensitive - 88% specific). In the second observer, moderate agreement was found in ASL CBF (0.584, 61% sensitive, 97% specific) and DSC CBF (0.649, 65% sensitive, 100% specific), and excellent agreement in DSC CBV (0.800, 89% sensitive, 90% specific).

CONCLUSION

It was observed that uncorrected DSC nCBV, DSC nCBF and ASL nCBF values were well correlated with each other. In qualitative evaluation, inter-observer and intra-observer agreement was higher in DSC CBV than DSC CBF and ASL CBF. In addition, DSC CBV is found more sensitive, ASL CBF and DSC CBF are found more specific for both observers. From a diagnostic perspective, all three parameters DSC CBV, DSC CBF and ASL CBF can be used, but it was observed that the highest rate belonged to DSC CBV.

Investigation of ligament, bone, synovial and plica pathologies accompanied by common extensor tendon in patients with lateral overuse syndrome of the elbow using magnetic resonance imaging

BACKGROUND

Tendinosis in the common extensor tendon and accompanying ligament, bone, and plica abnormalities can be observed on magnetic resonance imaging (MRI).

PURPOSE

To determine whether there is a difference between accompanying abnormalities according to the degree of common extensor tendon injury.

MATERIAL AND METHODS

Patients who underwent 1.5-T MRI tests with a prediagnosis of lateral overuse syndrome were retrospectively reviewed, and 56 patients who had an injury in the common extensor tendon (CET) were included. The degree of tendon and ligament injury, muscle signal change, bone marrow signal change, presence of joint effusion, and morphological features in the presence of plica were evaluated via MRI examinations of the elbow.

RESULTS

Overall, 32, 16, and eight patients had mild, moderate, and severe CET damage, respectively. As the severity of CET damage increased, the presence of joint effusion, and the presence and degree of damage to the lateral ulnar collateral ligament (LUCL) and radial collateral ligament (RCL) increased. The radiohumeral (RH) plica area was significantly larger in the group with mild CET damage. There was no statistically significant correlation between the severity of CET damage and the end of RH plica with a blind-end, coverage of one-third or more of the radius, its signal, thickness, and presence of olecranon fold.

CONCLUSION

As the severity of CET injury increases, damage to the LUCL, RCL, and the presence of effusion in the joint increases. RH plica should be evaluated in terms of concomitant pathology in patients with mild CET injuries on MRI.