1. External Pressure
1.1. Elastography
1.1.1. Ultrasonic Pressure Transducer
1.1.1.1. relationship between wave velocity and pressure has been shown to be almost linear
1.1.1.2. has not been used in penile rigidity studies yet
1.1.1.3. influenced by the type of medium inside
1.1.1.4. propagation dependent on the roughness condition of the vessel wall
1.1.1.5. can be affected by temperature (research has been done on ways to mitigate this)
1.1.1.6. need to measure multiple waves to gain higher accuracy
1.1.1.7. Pressure measured in MPa
1.1.1.8. size of pressure vessel used comparable to penis size
1.1.2. Shear wave elastography
1.1.2.1. no manual compression
1.1.2.2. certified by the US FDA
1.1.2.3. non-ionizing
1.1.2.4. non-invasive
1.1.2.5. same thermal and mechanical energy as conventional Doppler imaging
1.1.2.6. Resolution: measured in kPa
1.1.2.7. correlated with testosterone
1.1.2.8. does not necessarily change with erection mostly based on CCP stiffness (currently measured with penis biopsy samples)
1.1.2.9. dynamic elastography
1.1.3. Tissue Doppler Imaging
1.1.3.1. static elastography
1.1.3.2. classified in 4 grades (very low resolution)
1.1.3.3. rigidity was only observed
1.1.4. Compression Elastography
1.1.4.1. compression must be applied
1.1.4.2. static
1.1.4.3. based on differences before and after compression (baseline is patient dependent)
1.1.5. ARFI Method
1.1.5.1. deformed by push pulse in localized area
1.1.5.2. displacement based
1.1.5.3. acoustic radiation force
1.1.5.4. only applied for short period of time
1.1.6. Pharmaco-penile Duplex Sonography
1.1.6.1. current protocol performed in clinic
1.1.6.2. Resistance Index of the cavernous artery (corresponding to rigidity)
1.1.6.3. P-value was insignificant for RI on its own
1.1.6.4. Only parameter that returned significant was peak velocity of the deep dorsal vein
1.1.6.5. Focused on Venous ED
1.1.6.6. intracavernosal injections
1.1.6.7. classified in 3 grades (low resolution)
1.1.7. ARFI Method: Virtual Touch Tissue Quantification
1.1.7.1. can conduct evaluation at any portion of penis
1.1.7.2. no discomfort to patient (how was this shown)
1.1.7.3. no additional preparation needed
1.1.7.4. measures shear wave values
1.1.7.5. 3 SWV measurements at anterior, center, and posterior
1.1.7.6. 3 SWV measurements (radial direction) at glans penis, corpus penis and radix penis
1.1.7.7. Used Siemens ACUSON s200 0 US system
1.1.7.8. Resolution: 2.97 m/s
1.1.7.9. SWV negatively correlated with penile rigidity??
1.1.7.10. Semiquantitative clinical grading of erection
1.1.7.11. fixed box dimension of the target ROI
1.1.7.12. sensitive to movement artifacts
1.2. Blood Pressure Cuff
1.2.1. Hokanson Penile Cuff
1.3. Capacitance
1.3.1. Capacitor Method
1.3.1.1. only applicable to small diameter pressure vessels
1.4. Strain Gauge
1.4.1. Penile Gauge
1.4.1.1. affected by environment (temp & humidity)
2. Blood Flow Perfusion
2.1. Rigiscan
2.1.1. Measures radial rigidity which only takes into account ICP (not always an accurate measurement of ability for intromission)
2.1.2. uncomfortable for individual to wear (heavy item strapped to leg)
2.1.3. Rigidity reported in percentage with two decimal places
2.1.4. 2-3 hours for measurments
2.1.5. measurements taken every 15 seconds
2.1.6. store data of up to three 10 hour monitoring sessions
3. Circumference
4. Force
4.1. Penile Gauge
4.2. Direct Inflection Measurement
5. Internal Pressure
5.1. ICP (Intracavernosal Pressure)
5.1.1. Implants
5.2. ISP (Intraspongiosal pressure)
5.2.1. Pressure Measure Catheter