Table:
Hyperthyroidism
Other names	Overactive thyroid, hyperthyreosis

Triiodothyronine (T3, pictured) and thyroxine (T4) are both forms of thyroid hormone.
Specialty	Endocrinology
Symptoms	Irritability, muscle weakness, sleeping problems, fast heartbeat, heat intolerance, diarrhea, enlargement of the thyroid, weight loss[1]
Complications	Thyroid storm[2]
Usual onset	20–50 years old[2]
Causes	Graves' disease, multinodular goiter, toxic adenoma, inflammation of the thyroid, eating too much iodine, too much synthetic thyroid hormone[1][2]
Diagnostic method	Based on symptoms and confirmed by blood tests[1]
Treatment	Radioiodine therapy, medications, thyroid surgery[1]
Medication	Beta blockers, methimazole[1]
Frequency	1.2% (USA)[3]

A table may have multiple merged cells and we can represent a merged cell region by a JSON {'top-left':(A, B), 'bottom-right':(C, D)}. Here, '(A, B)' and '(C, D)' denote the coordinates (row_id, column_id) of the top-left and bottom-right cells of the merged regions, respectively. Now, based on the shown table image, please find all merged cells in this table and return their representations in the above format. Keep in mind that row and column IDs start from 1.

The merged cell area is: {'top-left':(1, 1), 'bottom-right':(1, 2)}.