Patient deprivation and perceived scan burden negatively impact the quality of whole-body MRI

The Psychological, Physiological, and Behavioral Responses of Patients to Magnetic Resonance Imaging (MRI): A Systematic Review and Meta-Analysis

BACKGROUND

MRI is generally well-tolerated although it may induce physiological stress responses and anxiety in patients.

PURPOSE

Investigate the psychological, physiological, and behavioral responses of patients to MRI, their evolution over time, and influencing factors.

STUDY TYPE

Systematic review with meta-analysis.

POPULATION

181,371 adult patients from 44 studies undergoing clinical MRI.

ASSESSMENT

Pubmed, PsycInfo, Web of Science, and Scopus were systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Quality appraisal was conducted with the Joanna Briggs Institute critical appraisal tools. Meta-analysis was conducted via Meta-Essentials workbooks when five studies were available for an outcome. Psychological and behavioral outcomes could be analyzed. Psychological outcomes were anxiety (State-Trait-Anxiety Inventory, STAI-S; 37) and willingness to undergo MRI again. Behavioral outcomes included unexpected behaviors: No shows, sedation, failed scans, and motion artifacts. Year of publication, sex, age, and positioning were examined as moderators.

STATISTICAL TESTS

Meta-analysis, Hedge's g. A P value <0.05 was considered to indicate statistical significance.

RESULTS

Of 12,755 initial studies, 104 studies were included in methodological review and 44 (181,371 patients) in meta-analysis. Anxiety did not significantly reduce from pre- to post-MRI (Hedge's g = -0.20, P = 0.051). Pooled values of STAI-S (37) were 44.93 (pre-MRI) and 40.36 (post-MRI). Of all patients, 3.9% reported unwillingness to undergo MRI again. Pooled prevalence of unexpected patient behavior was 11.4%; rates for singular behaviors were: Failed scans, 2.1%; no-shows, 11.5%; sedation, 3.3%; motion artifacts, 12.2%. Year of publication was not a significant moderator (all P > 0.169); that is, the patients' response was not improved in recent vs. older studies. Meta-analysis of physiological responses was not feasible since preconditions were not met for any outcome.

DATA CONCLUSION

Advancements of MRI technology alone may not be sufficient to eliminate anxiety in patients undergoing MRI and related unexpected behaviors.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 5.

The future of PSMA PET and WB MRI as next-generation imaging tools in prostate cancer

Radiolabelled prostate-specific membrane antigen (PSMA)-based PET-CT has been shown in numerous studies to be superior to conventional imaging in the detection of nodal or distant metastatic lesions. ⁶⁸Ga-PSMA PET-CT is now recommended by many guidelines for the detection of biochemically relapsed disease after radical local therapy. PSMA radioligands can also function as radiotheranostics, and Lu-PSMA has been shown to be a potential new line of treatment for metastatic castration-resistant prostate cancer. Whole-body (WB) MRI has been shown to have a high diagnostic performance in the detection and monitoring of metastatic bone disease. Prospective, randomized, multicentre studies comparing ⁶⁸Ga-PSMA PET-CT and WB MRI for pelvic nodal and metastatic disease detection are yet to be performed. Challenges for interpretation of PSMA include tracer trapping in non-target tissues and also urinary excretion of tracers, which confounds image interpretation at the vesicoureteral junction. Additionally, studies have shown how long-term androgen deprivation therapy (ADT) affects PSMA expression and could, therefore, reduce tracer uptake and visibility of PSMA⁺ lesions. Furthermore, ADT of short duration might increase PSMA expression, leading to the PSMA flare phenomenon, which makes the accurate monitoring of treatment response to ADT with PSMA PET challenging. Scan duration, detection of incidentalomas and presence of metallic implants are some of the major challenges with WB MRI. Emerging data support the wider adoption of PSMA PET and WB MRI for diagnosis, staging, disease burden evaluation and response monitoring, although their relative roles in the standard-of-care management of patients are yet to be fully defined.

Detection of distant metastases in rectal cancer: contrast-enhanced CT vs whole body MRI

OBJECTIVES

To evaluate the diagnostic performance of whole-body MRI (WB-MRI) including contrast-enhanced T1-weighted imaging (T1WI) and WB-DWI in rectal cancer initial staging.

METHODS

This retrospective study was approved by the IRB and the requirement of informed consent was waived. From September 2013 to Feb 2015, patients who underwent rectal MRI including WB-MRI, as well as chest and abdominopelvic CT for initial staging, were included. WB-MRI consisted of contrast-enhanced T1-weighted imaging and DWI covering neck to the pelvis. Three radiologists reviewed WB-MRI and CECT independently for the M-classification. The diagnostic performance of CECT and WB-MRI was compared using a reference standard incorporating histology, FDG-PET results, and clinical follow-up.

RESULTS

A total of 139 patients (male:female = 89:50, mean age 63.2 ± 12.4 years) were included and metastasis was observed in 15.2% (21/139). WB-MRI showed significantly higher specificity (96.7% [114/118] vs. 85.6% [101/118], p = 0.001) and positive predictive value (PPV) (80% [16/20] vs. 48.5% [16/33], p < 0.001) than CECT. However, there were no significant differences in sensitivity (76.2% [16/21] for both, p > 0.99) and negative predictive value (95.3% [101/106] at CECT vs. 95.8% [114/119] at WB-MRI, p = 0.77) between CECT and WB-MRI.

CONCLUSIONS

WB-MRI showed higher specificity and PPV than CECT in newly diagnosed rectal cancer. Adding WB-MRI to standard rectal MRI is a feasible option for initial staging workup of rectal cancer.

KEY POINTS

• WB-MRI showed a higher specificity and PPV than those of CECT for identifying metastasis at initial staging workup of rectal cancer. • WB-MRI and CECT did not show a significant difference in sensitivity and NPV for the M-classification. • WB-MRI can be used as an alternative to CECT for the initial M-classification modality in newly diagnosed rectal cancer.