An inductive sensor apparatus for brain diagnostics comprising: a first sensor coil connected with a first resistive, inductive, and capacitive circuit and a first frequency counter (110, 1410); a second sensor coil (114, 118) connected with a second RLC circuit and a second frequency counter (110, 1410), the second sensor coil having a larger or smaller diameter than the first sensor coil (124, 128), the first and second sensor coils forming a sensor unit; a memory storing control values derived from prior sensor coil resonant frequency measurements of one or more normal brains in vivo, each control value associated with a corresponding cranial location; a computer processor operatively connected with a machine-readable non-transitory medium embodying information indicative of instructions for causing the computer processor to perform operations comprising: generating (1701, 1702) measured values based on resonant frequency outputs from the first and second frequency counters (110, 1410) when the sensor unit is at a cranial location; determining the cranial location at which the measured values are associated; retrieving, from the memory, control values (1660, 1662) associated with the cranial location; comparing the measured values based on the resonant frequency outputs to the control values (1660, 1662) derived from the prior sensor coil resonant frequency measurements to generate deltas; comparing the deltas to a positive threshold and a negative threshold associated with each cranial location to ascertain an exceedance (440, 442, 444, 446, 550, 850), the exceedance having a sign and a magnitude; and outputting an indication based on the sign of the exceedance, and an indicator or display connected with the computer processor for the indications. a first sensor coil connected with a first resistive, inductive, and capacitive circuit and a first frequency counter (110, 1410); a second sensor coil (114, 118) connected with a second RLC circuit and a second frequency counter (110, 1410), the second sensor coil having a larger or smaller diameter than the first sensor coil (124, 128), the first and second sensor coils forming a sensor unit; a memory storing control values derived from prior sensor coil resonant frequency measurements of one or more normal brains in vivo, each control value associated with a corresponding cranial location; a computer processor operatively connected with a machine-readable non-transitory medium embodying information indicative of instructions for causing the computer processor to perform operations comprising: generating (1701, 1702) measured values based on resonant frequency outputs from the first and second frequency counters (110, 1410) when the sensor unit is at a cranial location; determining the cranial location at which the measured values are associated; retrieving, from the memory, control values (1660, 1662) associated with the cranial location; comparing the measured values based on the resonant frequency outputs to the control values (1660, 1662) derived from the prior sensor coil resonant frequency measurements to generate deltas; comparing the deltas to a positive threshold and a negative threshold associated with each cranial location to ascertain an exceedance (440, 442, 444, 446, 550, 850), the exceedance having a sign and a magnitude; and outputting an indication based on the sign of the exceedance, and generating (1701, 1702) measured values based on resonant frequency outputs from the first and second frequency counters (110, 1410) when the sensor unit is at a cranial location; determining the cranial location at which the measured values are associated; retrieving, from the memory, control values (1660, 1662) associated with the cranial location; comparing the measured values based on the resonant frequency outputs to the control values (1660, 1662) derived from the prior sensor coil resonant frequency measurements to generate deltas; comparing the deltas to a positive threshold and a negative threshold associated with each cranial location to ascertain an exceedance (440, 442, 444, 446, 550, 850), the exceedance having a sign and a magnitude; and outputting an indication based on the sign of the exceedance, and an indicator or display connected with the computer processor for the indications.