A new era in neuroradiology: ex vivo validation of in vivo imaging research

A Preliminary Vietnamese Comparative Study of Postgraduate Radiological Thesis Characteristics

Introduction:

Each country has its system of the training program, but to be concordant with the world in the radiology field, the process needs to have common points or common criteria. On maintaining the integrity of intersociety collaboration in the field of radiology, it is necessary to understand each country’s training program for each specialty.

Aim:

This retrospective study aims to compare the postgraduate thesis characteristics from various sources in the field of radiology.

Methods:

This was a retrospective study evaluating data that is publicly available online and at libraries and institutional review board approval, as such, was not demanded. We selected 40 published theses from the library of Pham Ngoc Thach University of Medicine and University of Medicine and Pharmacy at Ho Chi Minh City and Hanoi Medical University in Vietnam which graduated from 2008 to 2018. Of these, there were 10 PhD, 10 specialists II, 10 master’s, and 10 residency theses selected.

Results:

A total of 40 theses were analyzed from participants with a median age of 36.5. The male/female ratio was 23/17. Most of the theses were subspecialty in diagnostic radiology (87.5%) and focused on pathological radiology (95%). Adult patients were the major objectives of the theses accounted for 87.5% with predominant materials of magnetic resonance imaging counted for 47.5%. Theses in PhD group were the largest items regarding the total number of pages as well as the number of figures, and the number of references. Nonetheless, both domestic and international publications related to all theses were truly low.

Conclusion:

The postgraduate thesis of radiology in Vietnam has many different forms but mainly focuses on diagnostic and pathological radiology with materials of magnetic resonance imaging in adults. The number of international publications regarding the thesis was very small.

Postmortem imaging and neuropathologic correlations

Postmortem imaging refers to scanning autopsy specimens using magnetic resonance imaging (MRI) or optical imaging. This chapter summarizes postmortem imaging and its usefulness in brain mapping. Standard in vivo MRI has limited resolution due to time constraints and does not deliver cortical boundaries (e.g., Brodmann areas). Postmortem imaging offers a means to obtain ultra-high-resolution images with appropriate contrast for delineating cortical regions. Postmortem imaging provides the ability to validate MRI properties against histologic stained sections. This approach has enabled probabilistic mapping that is based on ex vivo MRI contrast, validated to histology, and subsequently mapped on to an in vivo model. This chapter emphasizes structural imaging, which can be validated with histologic assessment. Postmortem imaging has been applied to neuropathologic studies as well. This chapter includes many ex vivo studies, but focuses on studies of the medial temporal lobe, often involved in neurologic disease. New research using optical imaging is also highlighted.

Medial temporal cortices in ex vivo magnetic resonance imaging

This review focuses on the ex vivo magnetic resonance imaging (MRI) modeling of medial temporal cortices and associated structures, the entorhinal verrucae and the perforant pathway. Typical in vivo MRI has limited resolution due to constraints on scan times and does not show laminae in the medial temporal lobe. Recent studies using ex vivo MRI have demonstrated lamina in the entorhinal, perirhinal, and hippocampal cortices. These studies have enabled probabilistic brain mapping that is based on the ex vivo MRI contrast, validated to histology, and subsequently mapped onto an in vivo spherically warped surface model. Probabilistic maps are applicable to other in vivo studies.