Diffusion-weighted magnetic resonance imaging of primary cervical cancer in the detection of sub-centimetre metastatic lymph nodes.

BACKGROUND: Magnetic resonance imaging (MRI) has limited accuracy in detecting pelvic lymph node (PLN) metastasis. This study aimed to examine the use of intravoxel incoherent motion (IVIM) in classifying pelvic lymph node (PLN) involvement in cervical cancer patients. METHODS: Fifty cervical cancer patients with pre-treatment magnetic resonance imaging (MRI) were examined for PLN involvement by one subspecialist and one non-subspecialist radiologist. PLN status was confirmed by positron emission tomography or histology. The tumours were then segmented by both radiologists. Kruskal-Wallis tests were used to test for differences between diffusion tumour volume (DTV), apparent diffusion coefficient (ADC), pure diffusion coefficient (D), and perfusion fraction (f) in patients with no malignant PLN involvement, those with sub-centimetre and size-significant PLN metastases. These parameters were then considered as classifiers for PLN involvement, and were compared with the accuracies of radiologists. RESULTS: Twenty-one patients had PLN involvement of which 10 had sub-centimetre metastatic PLNs. DTV increased (p = 0.013) while ADC (p = 0.015), and f (p = 0.006) decreased as the nodal status progressed from no malignant involvement to sub-centimetre and then size-significant PLN metastases. In determining PLN involvement, a classification model (DTV + f) had similar accuracies (80%) as the non-subspecialist (76%; p = 0.73) and subspecialist (90%; p = 0.31). However, in identifying patients with sub-centimetre PLN metastasis, the model had higher accuracy (90%) than the non-subspecialist (30%; p = 0.01) but had similar accuracy with the subspecialist (90%, p = 1.00). Interobserver variability in tumour delineation did not significantly affect the performance of the classification model. CONCLUSION: IVIM is useful in determining PLN involvement but the added value decreases with reader experience.

Introducing point-of-care ultrasound through structured multifaceted ultrasound module in the undergraduate medical curriculum at the University of Hong Kong.

Incorporation of point-of-care ultrasound in the undergraduate medical curriculum is of great importance to ensure early exposure and safe use of the modality. We aimed to assess the students' learning experiences following implementing an ultrasound module in the medical curriculum at the University of Hong Kong. Medical students in semester 6 (n = 221) were enrolled in the module in 2018. It consisted of 1 hour of didactic lecture, followed by 3 hours of hands-on session. The students had the opportunity to enroll into a four-week Special Study Module to further practice their skills. The students had access to an e-learning platform to assist in their learning. Outcome measures include task-based performance, quizzes, feedback, and round-table discussion to assess the learning experiences. The module was highly rated by over 90% of students (response rate of 96%). Students practiced on peer subject on upper abdominal scanning. Post-training assessment showed an increment of 16% in their understanding of the modality. Students were motivated to enroll into the Special Study Module, where they were trained and became proficient with Focused Assessment with Sonography with Trauma. More than 86% of the students found the e-learning platform easy to use and assisted the training session. Round-table discussion suggested more simulated clinical cases to be added and expansion of future modules. Ultrasound module was successfully implemented into the undergraduate medical curriculum at the University of Hong Kong through new pedagogical approaches. This integration was highly rated by the medical students with improved awareness and better understanding of point-of-care ultrasound.