CT is the most commonly used modality for the detection and characterization of renal masses as well as presurgical planning and post-therapy surveillance. Indeterminate renal mass, renal adenocarcinoma, metastasis, monitoring of known renal mass. Kang S, Huang W, Pandharipande P, Chandarana H. Solid Renal Masses: What the Numbers Tell Us. MRI kidneys (renal) planning | MRI kidneys protocol| indications for Patient with renal insufficiency or hemodialysis; Rib mass/fracture (bony chest) Patient pregnant; MRA/MRV Chest w/ and w/o contrast . Appt Reason CPT CodeCPT CodeCPT CodeCPT Code 11801 SW 90 Street Suite 102 Miami FL 33186 Tel: 305/270-6001 Fax: 305/270-6955 MRI Chest and Left Scapula W/O&W/Contrast 71552 73220 A9579 . endobj 97 0 obj <> endobj 0000007606 00000 n 0000009995 00000 n Use T1 VIBE fat sat axial and coronal after the administration of IV gadolinium DTPA injection(copy the planning outlined above). Measurement of HU change after contrast administration using the earlier corticomedullary phase in a papillary RCC may result in erroneous categorization of the lesion as a nonenhancing cyst (see Fig. This review focuses on the CT and MR imaging protocol selection and optimization for renal mass evaluation. Ensure kidneys are well-centered in coil to ensure good signal at dome. 0000011123 00000 n Note the weight of the patient, > Patients with anaphylaxis or laryngeal edema should be discussed with radiologist before the exam and/or premedication is ordered. CPT Code(s) to Precert MRI Breast Newly Diagnosed Breast Cancer . Slices must be sufficient to cover both kidneys from two slices above the upper pole of kidneys down to two slices below the lower pole of kidney. Contrast material is excreted into the renal collection system, ureters, and bladder in this phase, allowing better visualization of these structures. If possible provide a chaperone for claustrophobic patients (e.g. endobj It has been reported that up to 66% more small renal masses are detected in the nephrographic phase compared with the corticomedullary phase. 'D]:iKv6"SJB^Dc{fmbxK7/T Dug1.r3hwL Recommended additional reformats: coronal and sagittal of each postcontrast scan series; 3-mm reconstruction section thickness without overlap. Combat the #1 denial reason - mismatched CPT-ICD-9 codes - with top Medicare carrier and private payer accepted diagnoses for the chosen CPT code. of localised blastemal-type Wilms tumour patients treated according to intensified treatment in the SIOP WT 2001 protocol, a report of the SIOP Renal Tumour Study Group (SIOP-RTSG). cardiac pacemaker, insulin pump biostimulator, neurostimulator, cochlear implant, and hearing aids) If RENAL FAILURE (Creatinine over 1.8)-ORDER EXAM WITHOUT CONTRAST. Check the positioning block in the other two planes. PDF Contrast Guidelines for Common CT/CTA MRI/MRA - ARA Diagnostic Imaging Power inject 2mL/sec. 0000013275 00000 n For patient comfort, if you. Computed tomography (CT) and MR imaging with intravenous (IV) contrast are the mainstays of renal mass evaluation. This modality enables the radiologist to detect intra-tumor fat resulting in a loss of signal intensity. MRI Abdomen with or without contrast 74183 Hematuria (blood in urine) Renal mass (cyst or solid) Transitional cell carcinoma of kidney Abnormal findings on other imaging studies Yes Body . The suggested imaging protocols are based on expert consensus, with the goal of balancing diagnostic efficacy and radiation exposure ( Table1 ). More CPT Codes: MRI | Nuclear Medicine | PET/CT | PET/MR | Ultrasound, Prep: NPO 2 hours for all studies w/ contrastArrival time: 30 minutes prior to exam for registration and prep, Dissection (if in conjunction with Abdomen and Pelvis CT w/contrast please see Chest w/ and w/o contrast and Abdomen Pelvis w/contrast (CPT Code 74177, IMG 698). Instruct the patient to hold their breath during image acquisition. Although the specifics of a renal protocol CT vary by institutions, the following phases in their various combinations commonly are used: precontrast phase, corticomedullary phase, nephrographic phase, and excretory phase ( Fig. Patient came in with rt foot pain and swel [b]MRI Extremity - Joint/Nonjoint[/b] Precontrast CT in a 62-year-old man shows a homogeneous hyperdense renal lesion (, CT in a 46-year-old man illustrates various enhancement phases in the kidneys. hbbd``b`@q+`a4A+$@>uwDA Q@t: Ask the patient to undress and change into a hospital gown Intracranial aneurysm clips (unless made of titanium) 0000008946 00000 n An appropriate angle must be given in the sagittal plane (perpendicular to the long axis of kidney). . Do not start scan until the patient has stopped breathing. Our radiologists work closely with OHSU MRI technologists in the art of creating optimal images using current technology. The excretory phase allows better depiction of the relationship between the mass and the renal collecting system. UB@&^v0c&]IG'#4-;j84j8BB"a6z2L0f#MG5ZP6l#AlX*k%rm9 R8XAe+S7"kTPPOA^vd@b/[wO;R}cH3@4B nMEz|pHj-ZBuQZr)AC6>*dZ3Yd'~AqClWIA{7^l!T , Although multiphase CT for tumor subtyping is promising, there are no prospective studies to date that have validated the reported enhancement threshold. Description by CPT Code* CPT Code Sacrum Sacral Insufficiency Fracture No MRI Sacrum wo 72196 SacralIliitis Tumor/Mass/Cancer/Mets Yes MRI Sacrum w/ & w/o 72197 Wrist Arthrogram TFCC tear Scaphoid nonunion Yes ** MR Upper Ext joint w/ Contrast Injection - Wrist 73222 25246 Intercarpal Ligaments Soft tissue ganglia Yes ** Rad exam - wrist 73115 stream > H= {,# $9N2)vELLc# qTxPec%={nv.lU'V{sMR7v';c9c%F. allergy) and time constraints. Notes: Indeterminate adrenal lesions are typically discovered incidentally on contrast enhanced 0000002227 00000 n Trigger & track. An important component of adrenal MRI protocol is chemical shift imaging (CSI). 0000011400 00000 n 1 0 obj %PDF-1.3 % > For the assessment of cystic kidney disease q-5GXRR{uj[qma..v.Q Dj QcU)0M'(_5Acc:4A1g59{P ClWk38?l4 VL K;~ZDm*HI(cCccsFGZvcW |w`90nT`GaGX -mY Q#x\G)!oMZJ,BCd3s HYmVgU*# n(7g(m SeH+ZFZ l5nbsOY>p]9;? Contrast-enhanced ultrasound is discussed in detail in a separate chapter. CPT Code 73721, Diagnostic Radiology (Diagnostic Imaging) Procedures, Diagnostic Radiology (Diagnostic Imaging) Procedures of the Lower Extremities - . Unable to process the form. For clinical responsibility, terminology, tips and additional info start codify free trial. NB: This article is intended to outline some general principles of protocol . Breathe the patient slowly so they have time to follow instructions. Subscribe to Anesthesia Coder today. Computed tomography (CT) and MR imaging are mainstays for renal mass characterization, presurgical planning of renal tumors, and surveillance after surgery or systemic therapy for advanced renal cell carcinomas. Our podiatrist states that she can report reading for MRI, if patient is bringing in the MRI disc with images and she read it [COLOR="#EE82EE"][/COLOR] Ok, so this seems silly, however, sometimes when reviewing information, there is not always a cut and dry answer to questions. endobj Adrenal glands protocol is an MRI protocol comprising a group of MRI sequences put together to further assess indeterminate adrenal lesions, in particular, lipid-poor adenomas.. These are fast single shot localisers with under 25s acqusition time which are excellent for localising abdominal structures. Patients with hives or rash must be pre-medicated for an IV contrast CT scan (not oral contrast). Active surveillance; postablation surveillance; postpartial nephrectomy surveillance, May be omitted for active surveillance if the primary goal is to determine renal mass size change, May be helpful after ablation or partial nephrectomy when collecting system injury is suspected, Postradical nephrectomy surveillance; systemic therapy surveillance, Can be included in patients at high risk of metastatic disease to improve detection of liver and pancreatic metastases. 2 AD). (, CT in a 69-year-old man with a papillary RCC demonstrating improved enhancement assessment on the nephrographic phase compared with the corticomedullary phase. 44 0 obj <> endobj Metal shrapnel or bullet, > Protocol Optimization for Renal Mass Detection and Characterization renal cell carcinomas and transitional cell > MRA carotid w/o contrast. Note: Instruct patient to arrive 45 minutes prior to exam for registration and prep. > Contrast-enhanced ultrasound with microbubble agents is a useful alternative for characterizing renal masses, especially for patients in whom iodinated CT contrast or gadolinium-based MR imaging contrast is contraindicated. Note: NPO 4 hours. The renal vasculature also enhances intensely in this phase, which can provide additional information for surgical planning if needed ( Fig. Coil: Torso Coil. MRI renal mass protocol v1.0 Society of Abdominal Radiology Disease Focused Panel on Renal Cell Carcinoma Zhen Jane Wang, MD, Project Leader Matthew S. Davenport, MD, Co-Chair Stuart G. Silverman, MD, Co-Chair Hersh Chandarana, MD Ankur Doshi, MD Gary M. Israel, MD John R. Leyendecker, MD Ivan Pedrosa, MD, PhD Steve Raman, MD Erick M. Remer, MD By applying enhancement thresholds, 1 study has shown that 4-phase CT attenuation profiles enabled differentiation of clear cell RCCs from other solid renal cortical masses, notably from papillary RCCs and lipid-poor AMLs. . Planning must be done in the breath hold T1 vibe coronal because the diaphragm will push down the upper abdominal organs during inhalation and change the position of the kidneys from the initial localizer scans. ), T1 In-opposed phase breath hold axial 4mm. On the other hand, the presence of intralesional calcification, regardless of the presence of fat, should prompt suspicion for malignancy, such as RCC. MR Renal Mass W/WO Protocol | OHSU Diagnostic Radiology (Diagnostic Imaging) Procedures, Diagnostic Radiology (Diagnostic Imaging) Procedures of the Lower Extremities, Copyright 2023. (, CT in a 37-year-old woman with hypertrophied column of Bertin. Slices must be sufficient to cover both kidneys from two slices above the upper pole of kidney down to two slices below the lower pole of kidney. Arterial phase (approximately 30-second delay) with field of view focused on the kidneys is recommended to better depict arteries and their relationship to the renal tumor. %PDF-1.7 endobj C`:+y(B^\}iO`,;6yg9&Mlc. %PDF-1.5 % (, Presurgical planning CT in a 65-year-old man with a left renal tumor. The recommended dose of gadolinium DTPA injection is 0.1 mmol/kg, i.e. JN HCC Renal Mass or Cyst Transitional Cell Carcinoma of Kidney Increased Liver . Lung Nodules (may be done w/contrast if ordering MD desires), Pneumonia (may be done w/contrast if ordering MD desires), Pleural effusion (may be done w/contrast if ordering MD desires), Airway imaging (includes TBM), Tracheal stenosis, Tracheal malacia (Tracheal Tree), Redo sternotomy for patients who cannot have contrast, Aortic or mitral valve for patients who cannot have contrast, Lung Cancer (may be done w/o Contrast if ordering MD desires), Chest Pain (may be done w/o contrast if ordering MD desires), Liver Mass Characterization/Surgical Planning, Post treatment HCC (not for metastatic surveillance), Renal Mass Characterization/Surgical Planning (if in conjunction with Pelvis CT w/contrast CPT Code 74178, IMG 783), Pancreatic mass characterization/surgical planning (if in conjunction with Pelvis CT w/contrast CPT Code 74178, IMG 783), Liver chemo embolization or RFA (if in conjunction with Pelvis CT w/ contrast CPT Code 74178, IMG 783), Abdomen and pelvis patients who cannot have contrast, Pre- and post-endoluminal grafting for patients who cannot have contrast, Diverticulitis/appendicitis/abscess/acute pancreatitis, Any other indication that is not already listed, Pre liver transplant/portal vein embolization, Gated TAVI (if in conjunction with Heart CT w/contrast (Morphology), CPT code 75572, IMG 7603), Malignancy staging/malignancy follow-up angiography, Failed colonoscopy (if with IV contrast, CPT Code 74262, IMG 2251), Patients that cannot be sedated or cannot stop blood thinners for conventional colonoscopy (if with IV contrast, CPT Code 74262, IMG 2251), Hematuria (if w/o 3D reconstructions, CPT Code 74178, IMG 2252), CT AIF/bypass evaluation/cold leg/leg ischemia, Coronary artery disease/Bypass graft evaluation, Neck mass/malignancy staging/malignancy follow (if contrast is not desired, w/o contrast CPT Code 70490, IMG 191), Acute or chronic sinusitis/nasal cavity polyps, Trauma/black eye/facial contusion/jaw injury, Facial weakness/neoplasm/malignancy/cellulitis/abscess, Intracranial aneurysm/stenosis/dissection, Subarachnoid hemorrhage (SAH)/Arteriovenous malformation (AVM), Extracranial aneurysm/stenosis/dissection, Problem cases unresolved by non-invasive imaging, Cervical myelopathy or radiculopathy in which fine bone detail is desired, Thoracic myelopathy or radiculopathy in which fine bone detail is desired, Lumbar radiculopathy in which fine bone detail is desired presurgical planning and mapping, Infection (if concern for septic joint should be aspirated prior to CT), Rotator cuff or labral injury, unable to get MRI, Triangular fibrocartilage (TFC) complex injury. An appropriate angle must be given in the sagittal plane (perpendicular to the long axis of kidney). 72146, 74141 72148. The code(s) have to match the requesting provider's order, which looks to be an "MRI RT FOOT". endstream endobj 102 0 obj <>stream 80 0 obj <>stream Oregon Health & Science University is dedicated to improving the health and quality of life for all Oregonians through excellence, innovation and leadership in health care, education and research. 9 ). 0 Instruct the patient to hold their breath during image acquisition. Patients with vomiting or dizziness with IV contrast or shellfish allergy do not require premedication. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/Annots[ 14 0 R 15 0 R] /MediaBox[ 0 0 792 612] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Corticomedullary phase typically is acquired 40 seconds to 70seconds after IV contrast injection (see Fig. 125 0 obj <>stream Nephrographic and excretory phases also are included, with the field of view expanded from diaphragm to iliac crest. Evaluation of the incidental kidney lesion - UpToDate For FREE Trial. 70547. <> 1 0 obj The corticomedullary and excretory phases together with the precontrast-phase and nephrographic-phase images may be helpful to subtype renal masses. Do not interleave images. Angiomyolipomas (AMLs) can be diagnosed confidently once intralesional macroscopic fat has been identified in the absence of other worrisome findings, such as intralesional calcification. > Current Procedural Terminology CPT 2022 MAGNETIC RESONANCE IMAGING - MRI COMPUTED TOMOGRAPHY - CT MAGNETIC RESONANCE ANGIOGRAHY - MRA MAGNETIC RESONANCE VENOGRAPHY - MRV . The excretory phase may be helpful for distinguishing urothelial cancers from RCCs and parapelvic or peripelvic cysts from hydronephrosis and for diagnosing calyceal diverticula. %PDF-1.5 5 ). e~20GPU#L 2014;202(6):1196-206. <>/Metadata 1078 0 R/ViewerPreferences 1079 0 R>> The precontrast and nephrographic phase images are used to evaluate for changes of tumor size or enhancement characteristics in cases of active surveillance or detecting enhancing tumor in post-treatment settings ( Fig. In contrast, papillary RCCs demonstrate greater enhancement at later phases. (IMG 2390) - fMRI (Functional MRI w/ Tractography) CPT Codes 70551 & 76377 . PDF MRI Abdomen Protocol - Adrenal - TRA Medical Imaging M}]JS+9uG7^E@h z/EZZ?_Fefmz-@vfpri)6KdK3:DHT8L2F1: X-Rays, CT Scans, MRI, and Other Tests for Adrenal Glands An appropriate angle must be given in the sagittal plane (parallel to the long axis of kidney). The field of view, whether restricted to the kidneys themselves or expanded to include from the diaphragm to the iliac crest, also depends on the clinical questions. Diphenhydramine (Benadryl) (optional): 50 mg PO to be taken 1 hour prior to exam. endstream endobj 98 0 obj <>]/Pages 89 0 R/Type/Catalog>> endobj 99 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]>>/Rotate 0/TrimBox[0.0 0.0 612.0 396.0]/Type/Page>> endobj 100 0 obj <> endobj 101 0 obj <>stream 73721 is for an MRI of lower extremity joint; 73718 is an MRI for "other than joint". 4 0 obj MRI CPT Codes - Mallinckrodt Institute of Radiology - Washington GU PROTOCOLS: CT cystogram: BCT G01: 3 phase: nc.90sec.6min, Primary eval or post-op bladder canc: CT Cystogram (Trauma) - Filled only: 1 phase (filled) Evaluate for bladder injury, or follow-up of bladder injury (low-dose) Renal Mass 3 phase: BCT G02: 3 phase: nc.90sec.6min: Evaluate renal mass: Renal Donor 3 phase: BCT G04: 3 phase: nc.art . <> PDF University Radiology To MRI & MRA Ordering Guide Ferromagnetic surgical clips or staples 'f2J}0y:[]m jB|+7)Hed6'BghE~1-&&y-:+qX$*4p:5Zt5_l^t}Zp@[?e[lI{'? ak+k)g3_%"-st*:@1LyrkzAK RbRY QpeWD4-g5EE9:K_tJ,s#ZxiBUo&9z(3>,m Sheth S & Fishman E. Multi-Detector Row CT of the Kidneys and Urinary Tract: Techniques and Applications in the Diagnosis of Benign Diseases. Corticomedullary and excretory phases may be acquired optionally. 8 ). Imaging is essential in renal mass characterization in order to guide appropriate treatment selections, because the management paradigm of localized renal tumors has evolved in recent years to include active surveillance and thermal ablation in addition to partial and radical nephrectomy. I am having controversial answers in our practice in reference to duplicate billing for code 72721. Therenal mass CT protocol is a multi-phasic contrast-enhanced examination for the assessment of renal masses. CNobM*KUfBC*w3!Nh!R=: jq`?xL_,NI{F1&p=P;e! Free-breathing sequence, so please position slices accordingly. Give 2L O2 if it will help with breath-holds UNLESS PATIENT HAS COPD OR ANOTHER REASON NOT TO GIVE O2. 6Mvw\Th_?\)&sEpka>yB" }T]),i7x7/:j]`)\AJ]%#-I> `-e$=nr&=>naj@r"0cTHaZegZ[lIi;Beh&/h]$Swt\' !uQ!FzRe?EjI-.'iJ~z]wN&:7W^Usn?pEl?dlMQ ?[?: ?L5tZD'UT]gUDoor Last updated: 4/12/19. % oD}tw.. Axial (, CT in a 75-year-old woman with a left renal lesion demonstrating higher lesion conspicuity in the nephrographic phase compared with the corticomedullary phase. Securely tighten the body coil using straps to prevent respiratory artefacts Breathe the patient slowly so they have time to follow instructions. Offer earplugs or headphones, possibly with music for extra comfort PDF Magnetic Resonance Imaging - Mri Magnetic Resonance Angiograhy - Mra Phase oversampling and, in the case of 3D blocks, slice oversample, must be used to avoid wrap around artefacts. The MR sensitivity for adenomas measuring 10-20 HU is nearly 100%, while that for lipid-poor adenomas measuring greater than 30 HU is significantly lower (13 . <>>> Papillary RCCs typically have low-level progressive enhancement that peaks in the nephrographic phase. 0000007963 00000 n Cancers | Free Full-Text | Pediatric Extra-Renal Nephroblastoma (Wilms endobj When further work-up for a renal mass is deemed necessary, additional imaging can be obtained using a multiphase renal protocol CT. Enhancement patterns across different phases after IV contrast injection can be used to distinguish renal cysts from solid tumors and may aid in subtyping of renal tumors. New HCPCS Level II modifier reports advanced diagnostic imaging provided to Medicare patients. (, Suggested computed tomography protocols from the Society of Abdominal Radiology Disease-focused panel on renal cell carcinoma. [B]MRI Extremity - Joint/Nonjoint[/B] An intravenous line must be placed with extension tubing extending out of the magnetic bore 4u|29q9E15x=mB^y_o: Ehh5W O J2p71H q Check before giving contrast. CPT Code 74170. View matching HCPCS Level II codes and their definitions. 2. The aim of this study is to investigate the feasibility of eliminating the nephrographic phase from the four-phase renal computed tomography (CT) imaging to a three-phase protocol without affecting its diagnostic value. . AJR Am J Roentgenol. 2 0 obj no financial relationships to ineligible companies to disclose. 0000007179 00000 n (, CT in a 64-year-old man with a renal mass illustrating the utility of excretory phase in delineating involvement of the collecting system. trailer > CT Abdomen with contrast (CPT 74160) or without and with contrast (CPT 74170) with suspicion of a solid organ lesion (liver, kidney, pancreas, spleen). Scanner preference: 1.5T. hb```b``)a`e``ld`@ 4">kvv6*g^.i#wVz7_[/P=6w,t9ijtOT ~+IbInz/?^zPY\ w BODY PART REASON FOR EXAM PROCEDURE NOTES CPT CODE HEAD AND NECK Sella/Pituitary Pituitary dysfunction Adenoma, Sellar or suprasellar mass MRI HEAD W AND W/O CONTRAST (UMC order appears as MRI BRAIN W AND W/O CONTRAST) 70553 Inner Ear (IAC) CPA tumor They vary widely in biological aggressiveness, ranging from benign tumors to high grade renal cell carcinomas (RCCs). , For example, prior studies have shown that clear celltype RCCs demonstrate peak enhancement during the corticomedullary phase. ADVERTISEMENT: Supporters see fewer/no ads. Last updated: 4/12/19 Premedication Protocol. However, Medicare is denying CO-B7 billing under our podiatrist. endstream endobj 45 0 obj <> endobj 46 0 obj <> endobj 47 0 obj <>stream PDF 2020 CPT Code Exam Ordering Guide - Imaging Healthcare HUIn@aHY 8?"[_ fs)95=m>SMZ}5}K?OKb m#r+Y rQ`Iv ^3J&)-aGUbL+B3MRg\xh%PZ 7mJ2S\J>-F]dazBzaa9B-mh9c\9`RB y;?5Zr|e~fhlw`m@b]z"tKp+#14^w]^wwt22*Z#OlA?rv1HDXM\m w`,3UE~^X_~1E1(S8lyLV7qL6D"98%eM-r!zU 0000031716 00000 n MRA carotid with contrast. MRI spine screening to include 3 separate. 0000042057 00000 n Charge as: Abdomen W/WO Give a pillow under the head and cushions under the legs for extra comfort [U]Non-joint [/U]studies are to be We have a separate company with an MRI unit and we were approved by Medicare. Some masses can be confidently characterized on these images without requiring a subsequent dedicated multiphase renal protocol CT or MR image. Monitor that patient is breath-holding. zb;5X/Cac Zvq\H2w;w;/~Ne#)*7!nG (]vS~(HakGK Z6M5f?CS e How We Do It: Managing the Indeterminate Renal Mass with the MRI Clear X:/QEZfG 0000002341 00000 n MSwnA) q%-#5Fms )fHde endstream endobj startxref Multiplanar reformats in the coronal and sagittal planes of each postcontrast scan series also can be done with 3-mm reconstruction section thickness without overlap. Renal Mass Characterization/Surgical Planning (if in conjunction with Pelvis CT w/contrast CPT Code 74178, IMG 783) Pancreatic mass characterization/surgical planning (if in conjunction . > For the assessment of xanthogranulomatous pyelonephritis 0000006342 00000 n Charge as: Abdomen W/WO. 0000000876 00000 n 0000004668 00000 n Prednisone: 50 mg PO (three doses total) to be taken 13 hours, 7 hours and 1 hour prior to appointment. CT EXAM CPT CODE REFERENCE Use this reference to quickly determine the correct exam for your patients based on the endstream endobj 103 0 obj <>stream Not all exams are available at all locations. 0000000016 00000 n > carcinoma) relative or staff ) <>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Most adrenal masses are detected first on abdominal CT scans, with an incidence of 0.6 to 1.3 percent on such scans. View any code changes for 2023 as well as historical information on code creation and revision. Plan the axial slices on the coronal plane; angle the position block parallel to the right and left renal pelvis. In this diagnostic procedure, the provider performs magnetic resonance imaging of a lower extremity joint without using contrast material.