Term
| WHAT ARE THE 3 MAJOR TYPES OF PLETHYSMOGRAPHY |
|
Definition
IMPEDANCE PLETHYSMOGRAPHY (IPG)
STRAIN-GAUGE PLETHYSMOGRAPHY (SPG)
AIR-CUFF PLETHYSMOGRAPHY (PNEUMOPLETHYSMOGRAPHY) |
|
|
Term
| DEFINITION OF PLETHYSMOGRAPHY |
|
Definition
| PLETHYSMOGRAPHY MEASURES CHANGES IN VOLUME |
|
|
Term
| WHAT DO WE EXPECT IF THROMBUS IN THE VEINS IS PRESENT |
|
Definition
IF THROMBUS IN THE VEINS IS PRESENT, 1. THE ABILITY FOR BLOOD TO POOL IN THE LOWER EXTREMITY VEINS WILL DECREASE GREATLY
( BECAUSE THE VEINS ARE ALREADY FILLED WITH BLOOD DUE TO THE OBSTRUCTING THROMBUS, AND CANNOT HOLD MUCH MORE BLOOD) AND 2. THE BLOOD OUTFLOW FROM THOSE VEINS WILL BE SIGNIFICANTLY SLOWER THAN NORMAL. AS YOU ALREADY KNOW, THE VEINS ARE CAPACITANCE VESSELS.PLETHYSMOGRAPHY MONITORS THE FILLING (CAPACITANCE) AND EMPTYING (OUTFLOW) OF THE VEINS. |
|
|
Term
| IMPEDANCE PLETHYSMOGRAPHY (IPG) |
|
Definition
| Measures small changes in the electrical resistance in the calf. |
|
|
Term
| STRAIN GAUGE PLETHYSMOGRAPHY (SPG) |
|
Definition
| + MEASURES CHANGES IN VOLUME (PHYSICAL SIZE) OF THE CALF. HERE IS HOW THE TEST WORKS. + A VERY THIN SILASTIC TUBE THAT IS FILLED WITH MERCURY IS WRAPPED AROUND THE PROXIMAL PORTION OF THE CALF AND CONNECTED TO THE RECORDING INSTRUMENT. + NEXT, A THIGH CUFF IS INFLATED TO 50-60 MM/HG FOR A FEW MINUTES. + AS VENOUS POOLING OCCURS, THE PHYSICAL SIZE OF THE CALF INCREASES AND STRETCHES THE SILASTIC TUBE. + RESISTANCE TO THE ELECTRICAL CURRENT FLOWING THROUGH THE TUBE INCREASES BECAUSE THE TUBE IS NOW LONGER WITH LESS CROSS SECTIONAL AREA. |
|
|
Term
|
Definition
| RECORDS PRESSURE CHANGES IN CALF CUFF REFLECTING CHANGES IN CALF VOLUME |
|
|
Term
| WHAT ARE NORMAL FINDINGS WITH VENOUS PLETHYSMOGRAPHY |
|
Definition
NORMAL FINDINGS:
Blood should readily pool in veins - rise in trace
Blood should swiftly flow out of veins - swift drop in trace with deflation of thigh cuff |
|
|
Term
| WHAT ARE ABNORMAL FINDINGS WITH VENOUS PLETHYSMOGRAPHY |
|
Definition
| IN THE ABNORMAL PATIENT WITH DEEP VEIN THROMBOSIS, THE VEINS ARE ALREADY FILLED WITH BLOOD THAT CANNOT FLOW OUT DUE TO THE OBSTRUCTING THROMBUS, SO THERE WILL BE A LESSER FILLING WITH A SMALLER RISE ON THE TRACING WHEN THE THIGH CUFF IS INFLATED. WHEN THE THIGH CUFF IS DEFLATED, THE BLOOD WILL FLOW OUT OF THE VEINS MORE SLOWLY DUE TO THE OBSTRUCTING THROMBUS, AND THIS WILL BE REFLECTED AS A SLOWER DROP IN THE TRACING. |
|
|
Term
|
Definition
| ARTERIAL PLETHYSMOGRAPHY MEASURES VOLUME CHANGES IN ARTERIAL VOLUME. THIS TEST IS NOT USED AS OFTEN AS CW DOPPLER WITH SEGMENTAL PRESSURES,HOWEVER, IT MAY BE OF USE WITH DIABETIC PATIENTS WHO HAVE CALCIFIED ARTERIES THAT CANNOT BE COMPRESSED WITH INFLATION OF PRESSURE CUFFS.SINCE PULSATILE ARTERIAL FLOW CAUSES CHANGES IN VOLUME THAT ARE OF SHORTER DURATION, AC COUPLING MUST BE USED.THIS TEST CAN BE USED TO DETECT SOME SEGMENTAL OBSTRUCTION OF THE ARTERIES. |
|
|
Term
| NORMAL FINDINGS WITH ARTERIAL PLETHYSMOGRAPHY |
|
Definition
NORMAL:
Quick upstroke
Sharp peak
Down stroke bowed toward baseline
Dicrotic notch may or may not be present |
|
|
Term
| ABNORMAL FINDINGS WITH ARTERIAL PLETHYSMOGRAPHY |
|
Definition
| AN ABNORMAL PULSE WAVEFORM HAS A PROLONGED UPSTROKE, A ROUNDED PEAK, A DOWN STROKE THAT IS BOWED AWAY FROM BASELINE, AND A LOSS OF SIGNAL AMPLITUDE. THIS TYPE OF PULSE WAVEFORM IS SUGGESTIVE OF SOME TYPE OF ARTERIAL OBSTRUCTION PROXIMAL TO THE BLOOD PRESSURE CUFF THAT PRODUCED THE WAVEFORM |
|
|
Term
|
Definition
| THE TRANSCUTANEOUS PARTIAL PRESSURE OF OXYGEN MEASUREMENT TESTING METHOD IS RELATED TO CUTANEOUS OXYGEN DELIVERY. IN ORDER FOR A WOUND TO HEAL AFTER AMPUTATION, SUFFICIENT OXYGEN MUST BE DELIVERED TO THE SITE IN ORDER FOR HEALING TO OCCUR.THIS TEST ALLOWS FOR DIRECT ASSESSMENT OF OXYGEN DELIVERY, IN ORDER TO PROVIDE THE PHYSICIAN WITH INFORMATION NEEDED TO DECIDE WHETHER HEALING IS LIKELY AT A SPECIFIC SITE. |
|
|
Term
|
Definition
| ANGIOGRAPHY (ALSO CALLED ARTERIOGRAPHY) IS A TEST THAT ENABLES BLOOD VESSELS TO BE VISUALIZED ON X RAY FILM AFTER THE VESSELS HAVE BEEN FILLED WITH A CONTRAST MEDIUM THAT IS OPAQUE TO X RAYS. + ANGIOGRAPHY DETECTS DISEASES THAT ALTER THE BLOOD VESSELS’ CHANNEL. |
|
|
Term
| CAPABILITIES OF ANGIOGRAPHY |
|
Definition
| ANGIOGRAPHY IS CAPABLE OF DETECTING ANEURYSMAL CHANGES, VESSEL STENOSIS OR OCCLUSION, AND + CHANGES IN BLOOD FLOW PATTERNS THAT LEAD TO TUMORS OR INJURED ORGANS. |
|
|
Term
|
Definition
Performed to demonstrate presence of brain aneurysm
Performed to visualize brain tumor pre-operatively |
|
|
Term
|
Definition
| Performed on patients suffering from TIA to evaluate for carotid artery stenosis or occlusion |
|
|
Term
| THE ARTERIES THAT ARE USED FOR ANGIOGRAPHY |
|
Definition
ARTERIES USED:
Common femoral artery (safest)
Axillary artery
Brachial artery
Carotid artery |
|
|
Term
|
Definition
| RISKS ASSOCIATED WITH ANGIOGRAPHIC PROCEDURES INCLUDE A SENSATION OF WARMTH AFTER INJECTION OF THE CONTRAST MATERIAL, ALLERGIC REACTION TO THE CONTRAST MATERIAL,AND DAMAGE TO THE BLOOD VESSELS AT THE SITE OF THE PUNCTURE OR ANYWHERE ALONG THE VESSELS. DAMAGE INCLUDES PUNCTURE SITE HEMATOMA, PSEUDOANEURYSM FORMATION, LOCAL ARTERIAL OCCLUSION, AND NEUROLOGIC COMPLICATIONS. |
|
|
Term
| MAGNETIC RESONANCE ANGIOGRAPHY (MRA) |
|
Definition
| AN MRA IS BASICALLY A METHOD OF PRODUCING EXTREMELY DETAILED PICTURES OF THE BLOOD VESSELS USING MRI TECHNOLOGY. THE ELECTROMAGNETIC ENERGY THAT IS RELEASED WHEN A PATIENT IS EXPOSED TO RADIOFREQUENCY WAVES IN A STRONG MAGNETIC FIELD IS MEASURED AND ANALYZED BY A COMPUTER. IMAGES MAY BE VIEWED ON A TV MONITOR. CONTRAST MATERIAL MAY OR MAY NOT BE USED.AN MRV IS AN EXAMINATION WHICH IS USED TO IMAGE THE VEINS. |
|
|
Term
|
Definition
| MRA CAN BE USED TO EVALUATE THE CAROTID ARTERIES IN THE NECK FOR ATHEROSCLEROTIC PLAQUE BUILD-UP. MRA MAY BE USED INSTEAD OF TRADITIONAL ANGIOGRAPHY WHEN ULTRASOUND SHOWS THAT DISEASE IS PRESENT. THIS WILL DISPENSE FOR THE NEED FOR CATHETER ANGIOGRAPHY. MRA IS ALSO USED AS A SCREENING TECHNIQUE TO CHECK FOR DISEASED INTRACRANIAL ARTERIES. |
|
|
Term
|
Definition
| BENEFITS OF MRA INCLUDE ELIMINATION OF POTENTIAL DAMAGE TO AN ARTERY THROUGH USE OF A CATHETER, THE RECOVERY TIME IS SHORTER AFTER AN MRA THAN FOR A CATHETER ANGIOGRAM, MRA IS LESS COSTLY THAN CATHETER ANGIOGRAM, THERE IS NO EXPOSURE TO IONIZING RADIATION, MRA PROVIDES ACCURACY PRIOR TO SURGICAL PROCEDURES. |
|
|
Term
|
Definition
| DISADVANTAGES OF MRA INCLUDE CLAUSTROPHOBIA WHEN THE PATIENT IS CONFINED IN AN MRA UNIT. THE MRA MAGNET WILL PULL ON ANY IRON CONTAINING MATERIAL SUCH AS PACEMAKERS, AN INTRAUTERINE DEVICE, A VASCULAR ACCESS PORT, PINS, SCREWS, OR STAPLES. PATIENTS MUST REMOVE HAIRPINS, JEWELRY, GLASSES, ETC. PRIOR TO THE EXAM. |
|
|
Term
|
Definition
| VENOGRAPHY IS ALSO CALLED PHLEBOGRAPHY OR A VENOGRAM.VENOGRAPHY IS AN X RAY PROCEDURE USED TO VISUALIZE THE VEINS IN THE LEG IN ORDER TO IDENTIFY THROMBUS.IN THE PAST, VENOGRAPHY WAS THE “GOLD STANDARD” FOR DEEP VEIN THROMBOSIS. ULTRASOUND IS NOW USED MORE OFTEN THAN VENOGRAPHY IN TESTING FOR DEEP VEIN THROMBOSIS IN THE LEG. THE TEST DETECTS FILLING DEFECTS IN THE VEINS. |
|
|
Term
| WHY IS LABORATORY ACCREDITATION IMPORTANT AND WHY IS IT NEEDED? |
|
Definition
WELL DEFINED STANDARDS OF PERFORMANCE, INTERPRETATION, AND REPORTING
TO Ensure minimal differences between:
Diagnostic laboratories
Individual vascular technologists
Interpreting physicians |
|
|
Term
|
Definition
| INTERSOCIETAL COMMISSION FOR THE ACCREDITATION OF VASCULAR LABORATORIES |
|
|
Term
| WHAT ORGANIZATION IS RESPONSIBLE FOR ACCREDITATION OF VASCULAR LABS IN USA? |
|
Definition
|
|
Term
| QUALITY ASSURANCE STATISTIC IS |
|
Definition
| COMPARISON OF NONINVASIVE STUDY WITH GOLD STANDARD (THE TRUTH) |
|
|
Term
| THE PURPOSE OF QUALITY ASSURANCE STATISTICS |
|
Definition
PROVIDES CONFIDENCE IN THE ACCURACY OF THE NONINVASIVE STUDY
IDENTIFIES LIMITATIONS OF STUDY, TECHNOLOGIST, OR PHYSICIAN |
|
|
Term
| WHAT IS THE GOAL OF QUALITY ASSURANCE STATISTICS |
|
Definition
| THE GOAL IS THAT STUDY RESULTS MATCH THE GOLD STANDARD 100% OF THE TIME! IN TRUTH, A MORE REALISTIC GOAL IS THAT STUDY RESULTS CORRELATE WITH THE GOLD STANDARD ABOUT 90% OF THE TIME. |
|
|
Term
|
Definition
| A TRUE POSITIVE IS PRESENT WHEN THE NONINVASIVE TEST (ULTRASOUND) AND THE GOLD STANDARD BOTH SHOW POSITIVE RESULTS. THE VENOGRAM IS OFTEN USED AS THE REFERENCE TEST (GOLD STANDARD) IN THE EVALUATION OF THE PATIENT WITH SUSPECTED DVT.IF THE VENOGRAM AND THE SONOGRAPHIC DVT BOTH ARE POSITIVE, WE HAVE A TRUE POSITIVE. |
|
|
Term
|
Definition
| A FALSE POSITIVE IS PRESENT WHEN THE NONINVASIVE TEST (ULTRASOUND) SHOWS A POSITIVE RESULT AND THE GOLD STANDARD SHOWS A NEGATIVE RESULT.FOR EXAMPLE, IF THE VENOGRAM SHOWS A NORMAL RESULT (NEGATIVE) AND THE ULTRASOUND SHOWS A POSITIVE RESULT FOR THROMBUS, WE HAVE A FALSE POSITIVE. |
|
|
Term
|
Definition
| A FALSE POSITIVE IS PRESENT WHEN THE NONINVASIVE TEST (ULTRASOUND) SHOWS A NEGATIVE RESULT AND THE GOLD STANDARD SHOWS A POSITIVE RESULT.FOR EXAMPLE, IF THE VENOGRAM SHOWS A POSITIVE RESULT AND THE ULTRASOUND SHOWS A NEGATIVE RESULT FOR THROMBUS, WE HAVE A FALSE NEGATIVE. |
|
|
Term
|
Definition
| A TRUE NEGATIVE IS PRESENT WHEN BOTH THE NONINVASIVE TEST (ULTRASOUND) SHOWS A NEGATIVE RESULT AND THE GOLD STANDARD SHOWS A NEGATIVE RESULT.FOR EXAMPLE, IF THE VENOGRAM SHOWS A NEGATIVE RESULT AND THE ULTRASOUND SHOWS A NEGATIVE RESULT FOR THROMBUS, WE HAVE A TRUE NEGATIVE. |
|
|
Term
|
Definition
- THE ABILITY OF A TEST TO DETECT DISEASE WHEN DISEASE IS PRESENT
HOW MANY POSITIVE NONINVASIVE ULTRASOUND TESTS WERE CONFIRMED AS POSITIVE BY THE GOLD STANDARD? |
|
|
Term
|
Definition
SENSITIVITY = True Positives/
True positives + False Negatives |
|
|
Term
|
Definition
THE ABILITY OF A TEST TO INDICATE THE ABSENCE OF DISEASE WHEN NO DISEASE IS PRESENT
HOW MANY OF THE NEGATIVE ULTRASOUND TESTS WERE CORRECTLY IDENTIFIED BASED UPON THE GOLD STANDARD? |
|
|
Term
|
Definition
True Negatives/
True Negatives + False Positives |
|
|
Term
| POSITIVE PREDICTIVE VALUE |
|
Definition
THE PERCENTAGE OF PATIENTS WHO HAVE POSITIVE NONINVASIVE TEST RESULTS WHO ACTUALLY HAVE DISEASE PRESENT
WHAT PERCENTAGE OF YOUR RESULTS PREDICTED ABNORMALITY (DISEASE)? |
|
|
Term
| POSITIVE PREDICTIVE VALUE FORMULA |
|
Definition
True Positives/
False Positives + True Positives |
|
|
Term
| NEGATIVE PREDICTIVE VALUE |
|
Definition
- THE PERCENTAGE OF PATIENTS WHO HAVE NEGATIVE NONINVASIVE TEST RESULTS WHO DO NOT HAVE DISEASE PRESENT
WHAT PERCENTAGE OF YOUR RESULTS PREDICTED ABSENCE OF DISEASE? |
|
|
Term
|
Definition
THE PERCENTAGE OF CORRECT NONINVASIVE DIAGNOSES
HOW GOOD IS THE NONINVASIVE TEST AT BOTH DETECTING AND RULING OUT DISEASE? |
|
|
Term
|
Definition
True Positives + True Negatives/
True Positives + False Negatives + True Negatives + False Negatives |
|
|
Term
| WHAT IS MESENTERIC ANGINA |
|
Definition
| STENOSIS IN SMA IS CALLED MESENTERIC ANGINA |
|
|
