Therapeutic Ultrasound: a Therapeutic Ultrasound: a Research based perspectiveResearch based perspective

JOSEPH A. GALLO, DSc, ATC, PTProfessor Hesser College PTA Program

Adjunct Faculty Franklin Pierce College PT ProgramClinician Performance Rehab

ObjectivesObjectivesTherapeutic UltrasoundTherapeutic Ultrasound

Discuss a Researched based perspective for Discuss a Researched based perspective for the clinical application of USthe clinical application of USApply research related to dosing USApply research related to dosing USEvaluate various coupling media Evaluate various coupling media Apply Clinical Model for dosing US based Apply Clinical Model for dosing US based on tissue composition and stages of healingon tissue composition and stages of healingDiscuss indications and contraindicationsDiscuss indications and contraindications

Past and Present Issues Related to Past and Present Issues Related to US Research US Research

Dead animal Models (40 Dead animal Models (40 -- 4545°°C range)C range)Flawed research methods and designsFlawed research methods and designsMany US Practice patterns have been based Many US Practice patterns have been based on “Journal of anecdotal medicine”on “Journal of anecdotal medicine”Baker KG. Phys Baker KG. Phys TherTher July 2001;81:1339July 2001;81:1339--1351 1351 Problem of placebo Problem of placebo vsvs placebo studiesplacebo studiesReasonable expectations Reasonable expectations

Ultrasound Ultrasound

Sinusoidal waveSinusoidal waveThermal agentThermal agentMechanical agentMechanical agentDoes not fall on electromagnetic spectrumDoes not fall on electromagnetic spectrumAcoustical spectrum (above 20,000 HZ)Acoustical spectrum (above 20,000 HZ)Human ear hears sound Human ear hears sound btwnbtwn 16,00016,000--20,00020,000

Basic Overview of production of Basic Overview of production of US US

A/C from wall A/C from wall Piezoelectric Piezoelectric crystal crystal crystal expands and crystal expands and contracts contracts results in production results in production of sound waves of sound waves vibration of vibration of molecules within human tissue molecules within human tissue causes physiologic effectscauses physiologic effects

Essential TerminologyEssential Terminology

Spatial Average Intensity (“intensity” W/cmSpatial Average Intensity (“intensity” W/cm22))Spatial Average Temporal Average Intensity Spatial Average Temporal Average Intensity (SATA): describes the net intensity delivered (SATA): describes the net intensity delivered based on the duty cycle selected based on the duty cycle selected

e.g. 1.0 W/cme.g. 1.0 W/cm22, pulsed 50%, =.5 W/cm, pulsed 50%, =.5 W/cm22

ERAERABNR BNR

Frequency: Clinical Implications Frequency: Clinical Implications

Depth of PenetrationDepth of Penetration1 MHz…………………Deep ( up to 5 cm)1 MHz…………………Deep ( up to 5 cm)3 MHz……Superficial (3 MHz……Superficial (≤≤ 2.5 cm)2.5 cm)11

Efficiency of heating:Efficiency of heating:3 MHz heats approx 3 3 MHz heats approx 3 xx’’ss faster than 1 MHzfaster than 1 MHz22

1. Hayes et al JAT 2004;39(3):2301. Hayes et al JAT 2004;39(3):230--2342342. Draper et al. JOSPT 1995;22:1422. Draper et al. JOSPT 1995;22:142--150150

Application techniqueApplication technique

Size of the treatment area: 2Size of the treatment area: 2--3 3 x’sx’s ERAERASpeed of sound head: *4Speed of sound head: *4--8 cm per second8 cm per secondCoupling IssuesCoupling IssuesAirAirHairHairUnder water treatmentUnder water treatment

* Poster presentation NATA 2004 Baltimore* Poster presentation NATA 2004 Baltimore

Pulsed US Pulsed US

Minimizes unwanted heating effects at a Minimizes unwanted heating effects at a given intensity proportional to the duty given intensity proportional to the duty cycle selectedcycle selectedSATA intensity is an important SATA intensity is an important consideration in dosing PUSconsideration in dosing PUSMyth: selecting PUS eliminates all heating Myth: selecting PUS eliminates all heating effects at all intensities effects at all intensities

SATA Study (JOSPT July 04’)SATA Study (JOSPT July 04’)Gallo, Draper, Brody, Gallo, Draper, Brody, Fellingham Fellingham

The research questionThe research questionWhat is the difference in the extent of tissue What is the difference in the extent of tissue heating using the following US parameters?heating using the following US parameters?

CUS (3 MHz, .5 w/cmCUS (3 MHz, .5 w/cm22, 10 min) , 10 min) vs.vs.

PUS (PUS (3 MHz, 1.0 w/cm3 MHz, 1.0 w/cm22, pulsed 50%, 10 min) , pulsed 50%, 10 min)

CUS = continuous ultrasound CUS = continuous ultrasound PUS = pulsed ultrasound PUS = pulsed ultrasound

Results SATA StudyResults SATA Study

GastrocnemiusGastrocnemius Muscle Temperature(°C) Changes Muscle Temperature(°C) Changes (Mean (Mean ±± SD) and Rate of Heating per Minute SD) and Rate of Heating per Minute ((°°C/min) During a 10 minute Ultrasound Application C/min) During a 10 minute Ultrasound Application

0.280.282.82.8++ .7.738.138.1++ .6.635.335.3++ .7.7PulsedPulsed††

0.280.282.82.8++ .8.838.438.4++ .8.835.535.5++ .9.9Continuous*Continuous*

RateRateChangeChangePeakPeakBaselineBaselineTreatmentTreatment

* 0.5 W/cm2 intensity, 100% duty cycle, 3 MHz† 1.0 W/cm2 intensity, 50% duty cycle, 3 MHz

Conclusion SATA studyConclusion SATA study

Pulsed ultrasound can heatPulsed ultrasound can heat“Inadvertent overdosing of acute “Inadvertent overdosing of acute inflammatory conditions is a possibility if inflammatory conditions is a possibility if low enough duty cycles and spatial average low enough duty cycles and spatial average temporal average intensities are not temporal average intensities are not selected”selected”

Pulsed US (Pulsed US (NonthermalNonthermal) ) Physiologic EffectsPhysiologic Effects

Increase macrophage responsivenessIncrease macrophage responsivenessIncreased intracellular calcium synthesisIncreased intracellular calcium synthesisIncreased skin and cell membrane Increased skin and cell membrane permeability (greater than CUS)permeability (greater than CUS)Increased protein synthesis by fibroblastsIncreased protein synthesis by fibroblastsIncreased early fibroblastic activity leading Increased early fibroblastic activity leading to accelerated tissue healingto accelerated tissue healing

NonthermalNonthermal USUS

Mechanism of actionMechanism of actionResearch on dosing for tissue healingResearch on dosing for tissue healingClinical recommendations for dosageClinical recommendations for dosagePUS PUS vsvs low dose continuous US (.2 W/cmlow dose continuous US (.2 W/cm22))PUS advocated for PUS advocated for phonophono

CUSCUS

Mild (1Mild (1ºº C) C) to vigorous heating (to vigorous heating (≥≥44ººC) C) is is achievableachievableExtent of heat build up depends on:Extent of heat build up depends on:FrequencyFrequencyIntensityIntensityDuration of treatmentDuration of treatmentTissue composition Tissue composition

Clinical Example of Pearls and Clinical Example of Pearls and Pitfalls of Dosing USPitfalls of Dosing US

US to US to PiriformisPiriformis Muscle for Deep Heating Muscle for Deep Heating using 1.5 W/cmusing 1.5 W/cm2 2 at 1 MHzat 1 MHzNote: A 4 deg Celsius net increase or a total Note: A 4 deg Celsius net increase or a total tissue temp increase tissue temp increase ≥≥ 40 deg Celsius is 40 deg Celsius is needed to optimize tissue extensibility needed to optimize tissue extensibility (Draper/Prentice. Therapeutic Ultrasound. Therapeutic Mod in Spo(Draper/Prentice. Therapeutic Ultrasound. Therapeutic Mod in Sports rts Med. McGrawMed. McGraw--Hill; 1999:207Hill; 1999:207--244)244)(Warren KG et al. (Warren KG et al. ElongElong of rat tail tendon:effect of load and temp. of rat tail tendon:effect of load and temp. Arch Arch PhyPhy Med Med RehabilRehabil. 1971;52:465. 1971;52:465--474.)474.)

How long should we How long should we sonatesonate??

“The Answer”“The Answer”

1.5 W/cm1.5 W/cm2 2 at a freq of 1 MHz generates a heating at a freq of 1 MHz generates a heating rate of .3rate of .3°°C/min C/min (Draper et al. JOSPT. 1995;22:142(Draper et al. JOSPT. 1995;22:142--150)150)

.3.3°°C X 5 min = 1.5C X 5 min = 1.5°°CC

.3.3°°C X 7 min = 2.1C X 7 min = 2.1°°CC

.3.3°°C X 9 min = 2.7C X 9 min = 2.7°°CC

.3.3°°C X 12 min = 3.6C X 12 min = 3.6°°CC

.3.3°°C X 13 min = 3.9C X 13 min = 3.9°°CC

Heating rate (Heating rate (°°C/min) from Draper et al JOSPT C/min) from Draper et al JOSPT 1995. 1995.

Clinical Model for Dosing CUSClinical Model for Dosing CUSConsiderationsConsiderations

Stage of tissue healingStage of tissue healingDesired goal of treatmentDesired goal of treatmentDepth of Target tissueDepth of Target tissueTarget tissue composition Target tissue composition Tendon study (Chan et al JAT 33:2; 1998) Tendon study (Chan et al JAT 33:2; 1998) Mild, moderate, vigorous heatingMild, moderate, vigorous heatingEquipment (heating rates vary)Equipment (heating rates vary)40 deg C threshold 40 deg C threshold vsvs Net increase of 4 deg CNet increase of 4 deg CPt perception at 40 deg C Pt perception at 40 deg C (Merrick JOSPT, July 2003)(Merrick JOSPT, July 2003)

Optimal Therapeutic Dosage

Tissue Healing

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Clinical Dosing Model for Clinical Dosing Model for vigorous heating vigorous heating

The 4 classifications The 4 classifications Deep muscle Deep muscle Superficial muscle Superficial muscle Deep tendon/ligamentDeep tendon/ligamentSuperficial tendon/ligament Superficial tendon/ligament

Heating rate data for muscle from Draper et al JOSPT 1995.Heating rate data for muscle from Draper et al JOSPT 1995.

Clinical Model for Dosing US Clinical Model for Dosing US Vigorous HeatingVigorous Heating

Deep Muscle (3Deep Muscle (3--5 cm deep)5 cm deep)Duty Cycle: 100% (continuous)Duty Cycle: 100% (continuous)Frequency: 1 MHzFrequency: 1 MHzIntensity: 1.5 W/cmIntensity: 1.5 W/cm2 2

Heating Rate: .3Heating Rate: .3ººC/min C/min Time: 13 min (13 min x .3Time: 13 min (13 min x .3°° C/min = 3.9C/min = 3.9°°C) C)

•• Heating rate calculations may vary based on Heating rate calculations may vary based on manufacturer manufacturer (Merrick JOSPT July 2003)(Merrick JOSPT July 2003)

Clinical Model for Dosing US Clinical Model for Dosing US Vigorous HeatingVigorous Heating

Superficial Muscle (Superficial Muscle (≤≤ 2.5 cm)2.5 cm)Duty Cycle: 100% (continuous)Duty Cycle: 100% (continuous)Frequency: 3 MHzFrequency: 3 MHzIntensity: .5 W/cmIntensity: .5 W/cm2 2 –– 1.0 W/cm1.0 W/cm22

Heating Rate .3Heating Rate .3°° C/min C/min -- .6.6°° C/minC/minTime: 13 min at .5 W/cmTime: 13 min at .5 W/cm2 2 (.3 x 13=3.9(.3 x 13=3.9ººC)C)

7 min at 1.0 W/cm7 min at 1.0 W/cm2 2 (.6 x 7=4.2(.6 x 7=4.2ººC)C)

Caution: 3 MHz heats 3xCaution: 3 MHz heats 3x’’s greater than 1 MHz s greater than 1 MHz patient feedback over rules all dosage calculationspatient feedback over rules all dosage calculations

Clinical Model for Dosing US Clinical Model for Dosing US Vigorous Heating Vigorous Heating

Superficial Tendon/Ligament (Superficial Tendon/Ligament (≤≤ 2.5 cm)2.5 cm)•• Duty Cycle: 100% (continuous)Duty Cycle: 100% (continuous)•• Frequency: 3 MHzFrequency: 3 MHz•• Intensity: .5 W/cmIntensity: .5 W/cm22 –– 1.0 W/cm1.0 W/cm2 2

•• Time: 7 min at .5 W/cmTime: 7 min at .5 W/cm2 2

44--5 min at 1.0 W/cm5 min at 1.0 W/cm22

•• Rationale: superficial tendon heats 3.45 faster than muscle thanRationale: superficial tendon heats 3.45 faster than muscle than mm. mm.

(Chan et al. J (Chan et al. J AthlAthl Train. 1998;33:130Train. 1998;33:130--135) 135)

Clinical Model for Dosing US Clinical Model for Dosing US Vigorous HeatingVigorous Heating

Deep Tendon/Ligament (3Deep Tendon/Ligament (3--5 cm deep)5 cm deep)•• Duty Cycle: 100% (continuous)Duty Cycle: 100% (continuous)•• Frequency: 1 MHzFrequency: 1 MHz•• Intensity: 1.5 W/cmIntensity: 1.5 W/cm22

•• Time: 10 minTime: 10 min•• Rationale: Rationale: Collagen rich tissue such as tendon Collagen rich tissue such as tendon

heats 3.45 heats 3.45 x’sx’s faster than mm. However, some US faster than mm. However, some US is absorbed in superficial tissue prior to reaching is absorbed in superficial tissue prior to reaching deep tissue.deep tissue.

Clinical Recommendations for Clinical Recommendations for the Use of Pulsed USthe Use of Pulsed US

Pulsed US Pulsed US -- Superficial Tissue (Superficial Tissue (≤≤2.5 cm)2.5 cm)•• Duty Cycle: 20%Duty Cycle: 20%•• Frequency: 3 MHzFrequency: 3 MHz•• ≤≤ .5 W/cm.5 W/cm2 2

•• Time: 7 minTime: 7 min•• Rationale……..Rationale……..

Clinical Recommendations for Clinical Recommendations for Pulsed US Pulsed US

Pulsed US Pulsed US –– Deep Tissue ( Deep Tissue ( ≥≥3cm)3cm)Duty Cycle: 20%Duty Cycle: 20%Frequency: 1 MHz Frequency: 1 MHz ≤≤ .5 W/cm.5 W/cm22

Time: 7 minTime: 7 minRationaleRationale……..

Stretching windowsStretching windows“time period of vigorous heating when tissue will “time period of vigorous heating when tissue will

undergo greatest elongation”undergo greatest elongation”

Muscle: 3.3 minute window post Muscle: 3.3 minute window post sonationsonationTendon/ligament: 5 minute window post Tendon/ligament: 5 minute window post sonation sonation Clinical implications: begin to put tissue on stretch Clinical implications: begin to put tissue on stretch during the tail end of the treatment, when the during the tail end of the treatment, when the tissue is warm and continue stretching or tissue is warm and continue stretching or mobilization, or cross friction STM during the first mobilization, or cross friction STM during the first five minutes post treatment five minutes post treatment

Draper et al. Draper et al. AthlAthl Train. 1995;30:4Train. 1995;30:4

Draper et al. Draper et al. AthlAthl Train. 1996;31:139Train. 1996;31:139--143143

TendinopathyTendinopathy

Acute TendonitisAcute TendonitisV.S.V.S.

TendinosisTendinosis: collagen degeneration with no : collagen degeneration with no histological signs of inflammationhistological signs of inflammation

•• Differences in clinical recommendations for Differences in clinical recommendations for treatment……treatment……

Additive Effect of HP + US Additive Effect of HP + US

Hot pack produces peak increase in muscle Hot pack produces peak increase in muscle ((gastrocgastroc) tissue temperature at 15 minute duration ) tissue temperature at 15 minute duration (3.4(3.4°°C at 1cm, 1.0C at 1cm, 1.0°°C at 3 cm) C at 3 cm)

Preheating with hot pack (15 min) prior to 1 MHz Preheating with hot pack (15 min) prior to 1 MHz CUS at 1.5 W/cmCUS at 1.5 W/cm2 2 (10 min) facilitates (10 min) facilitates deep/vigorous heating with 3 minutes less deep/vigorous heating with 3 minutes less sonationsonation timetime

Draper et al. J Draper et al. J AthlAthl Train. 1998. 33:21Train. 1998. 33:21--2424

Coupling media Coupling media

Gel: “gold standard”Gel: “gold standard”Underwater technique: Heats mm to Underwater technique: Heats mm to approximately 50% of the peak temp obtained approximately 50% of the peak temp obtained with gel.with gel.11

AquaflexAquaflex disc: No diff in mm temp increase disc: No diff in mm temp increase when compared to gel.when compared to gel.22

OthersOthers

1. Draper et al. J 1. Draper et al. J OrthopOrthop Sports Phys Sports Phys TherTher. 1993:17.. 1993:17.

2. Merrick et al. J 2. Merrick et al. J OrthopOrthop Sports Phys Sports Phys TherTher. 2002:32;216. 2002:32;216--220.220.

All All phonophono preparations are not preparations are not equalequal

Hydrocortisone creams do not transmit Hydrocortisone creams do not transmit Ultrasound effectivelyUltrasound effectively11

TheragesicTheragesic™™BiofreezeBiofreeze™™ mixed 1:1 with mixed 1:1 with AquasonicAquasonic™™ gelgel22

OthersOthers

1. 1. CameronMHCameronMH, Monroe LG. Phys , Monroe LG. Phys TherTher. 72:142. 72:142--148, 1992.148, 1992.2. 2. MyrerMyrer, , MeasomMeasom and and FellinghamFellingham. JAT. 36:20. JAT. 36:20--26, 2001. 26, 2001.

ExogenExogen Home US UnitHome US Unit

Enhanced bone healing of nonunion Enhanced bone healing of nonunion fractures.fractures.UnadjustableUnadjustable preset Low intensity PUS preset Low intensity PUS parameters parameters 1.5 MHz frequency1.5 MHz frequency20% duty cycle20% duty cycle.15 W/cm.15 W/cm22

2020--30 minutes daily30 minutes daily

ContraindicationsContraindications

Cancerous LesionsCancerous Lesions1,2,3,4,51,2,3,4,5

Acute Injury or hemorrhage (thermal)Acute Injury or hemorrhage (thermal)1,51,5

Circulatory Insufficiency (thermal)Circulatory Insufficiency (thermal)1,3,51,3,5

Deficits in sensation over the area to be treated Deficits in sensation over the area to be treated (thermal)(thermal)1,3,51,3,5

MethylmethacrylateMethylmethacrylate (cemented joint replacements) (cemented joint replacements) 2,42,4

Over Plastic implantsOver Plastic implants1,21,2

1=Belanger, 2=Cameron, 3=1=Belanger, 2=Cameron, 3=MichlovitzMichlovitz 4= 4= DenegarDenegar, 5 = Starkey , 5 = Starkey

Contraindications Cont..Contraindications Cont..

PacemakerPacemaker1,2,3,4,51,2,3,4,5

Over the heart Over the heart 3,4,53,4,5

Over skin that has been exposed to radiation Over skin that has been exposed to radiation therapytherapy11

Over the abdomen low back, or pelvic area during Over the abdomen low back, or pelvic area during pregnancypregnancy1,2,3,4,51,2,3,4,5

Implanted Implanted neurostimulationneurostimulation systems (systems (medtronicmedtronictype)type)11

1=Belanger, 2= Cameron, 3=1=Belanger, 2= Cameron, 3=MichlovitzMichlovitz, 4=, 4=DenegarDenegar, 5= Starkey , 5= Starkey

Contraindications Cont..Contraindications Cont..

Over Over thromboticthrombotic areas areas (thrombophlebitis/DVT)(thrombophlebitis/DVT)1,2,3,51,2,3,5

Over infected lesionsOver infected lesions1,4,51,4,5

Over the eyesOver the eyes1,2,3,4,51,2,3,4,5

Over the reproductive organsOver the reproductive organs1,2,3,4,51,2,3,4,5

Directly over the spinal cord after laminectomyDirectly over the spinal cord after laminectomy1,2,41,2,4

1=Belanger, 2= Cameron, 3=1=Belanger, 2= Cameron, 3=MichlovitzMichlovitz, 4 = , 4 = DenegarDenegar , 5=Starkey, 5=Starkey

A few words about……….A few words about……….

Metal implants Metal implants EpiphysealEpiphyseal plates plates

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