Publications by authors named "Parham Pezeshk"

25 Publications

  • Page 1 of 1

3D MRI of the Rheumatic Diseases.

Semin Musculoskelet Radiol 2021 Jun 21;25(3):425-432. Epub 2021 Sep 21.

Division of Musculoskeletal Radiology, Department of Radiology, UT Southwestern Medical Center, Dallas, Texas.

Magnetic resonance imaging (MRI) is commonly used to evaluate musculoskeletal pathologies due to its high spatial resolution and excellent tissue contrast. The diagnosis of rheumatic diseases can often be challenging. Investigation with conventional two-dimensional MRI is helpful for diagnosis and monitoring treatment. In the past few years, three-dimensional (3D) MRI has been more commonly used to assess joint pathologies including inflammatory and rheumatic diseases. This review discusses the techniques and protocols of 3D MRI and its diagnostic yield in the assessment of rheumatic diseases, along with different examples.
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http://dx.doi.org/10.1055/s-0041-1731058DOI Listing
June 2021

3-T MRI of the Ankle Tendons and Ligaments.

Clin Sports Med 2021 Oct;40(4):731-754

Division of Musculoskeletal Imaging and Intervention, Department of Radiology, University of Washington Medical Center, UW Radiology-Roosevelt Clinic, 4245 Roosevelt Way Northeast, Box 354755, Seattle, WA 98105, USA. Electronic address:

Ankle sprain is the most common injury in athletic populations. Ligament and tendon pathologies of the ankle are common, ranging from traumatic injuries to degeneration leading to chronic pain and acquired foot deformities. MRI is the imaging modality of choice to evaluate tendon and ligament pathology of the ankle, specifically derangements of tendons and ligaments. 3-T MRI offers improved imaging characteristics relative to 1.5-T MRI, allowing for better delineation of anatomic detail and pathology. This article provides a review of the anatomy and common pathologies of the ankle ligaments and tendons using high-resolution 3-T MRI.
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http://dx.doi.org/10.1016/j.csm.2021.05.009DOI Listing
October 2021

Does Presurgical Magnetic Resonance Neurography Predict Surgical Gap Size in Trigeminal Class IV and V Injuries?

J Oral Maxillofac Surg 2021 Jul 26. Epub 2021 Jul 26.

Associate Professor, Radiology & Orthopedic Surgery, Chief Musculoskeletal Radiology, Department of Radiology, University of Texas Southwestern, Dallas, TX.

Purpose: The accuracy of magnetic resonance neurography (MRN) for quantitative assessment of nerve injury gap is unknown. We tested the hypothesis that presurgical MRN predicts the final surgical gap size after neuroma resection at the time of surgery.

Materials And Methods: This was a retrospective, single-blinded, nonrandomized cohort study on 43 patients with Sunderland Class IV and V injuries of the inferior alveolar (IAN) or the lingual nerve (LN). The MRN maxillofacial protocol was performed on a 3T scanner and was read by 2 musculoskeletal radiologists to determine the maximum size of neuroma and the abnormal nerve segment. Two independent variables were recorded during surgery: 1) the length of neuroma from histologic specimens since only 9 of the 43 neuroma size measurements were accurately measureable at the time of surgery; and 2) the length of nerve gap size after the neuroma was removed and normal fascicles were identified.

Results: There were 7 IAN and 36 LN cases analyzed. The mean time in months from injury to MRN was 6.97 ± 9.18 and MRN to surgery was 1.21 ± 1.4. The mean length of the neuroma at surgery was 7.22 ± 2.78 mm and mean nerve gap size was 12.02 ± 4.41 mm. Intraclass coefficient (ICC) agreement was fair for abnormal nerve thickness and neuroma length (ICC = 0.28, 0.39) while it was moderate for neuroma thickness and abnormal nerve length (0.50, 0.59). There was no significant correlation between MRN based measurements and surgical gap size for both readers (P > .05).

Conclusions: Abnormal nerve and neuromas of the peripheral trigeminal nerve as identified on MRN imaging demonstrates no correlation of the assessed MRN findings with the final surgical gap after neuroma removal.
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http://dx.doi.org/10.1016/j.joms.2021.07.023DOI Listing
July 2021

Sacrum magnetic resonance imaging for low back and tail bone pain: A quality initiative to evaluate and improve imaging utility.

World J Methodol 2021 Jul 20;11(4):110-115. Epub 2021 Jul 20.

Department of Radiology, UT Southwestern, Dallas, TX 75390, United States.

As quality and cost effectiveness become essential in clinical practice, an evidence-based evaluation of the utility of imaging orders becomes an important consideration for radiology's value in patient care. We report an institutional quality improvement project including a retrospective review of utility of sacrum magnetic resonance (MR) imaging for low back pain at our institution over a four-year period and follow-up results after physician education intervention. Sacral MR imaging for low back pain and tailbone pain were only positive for major findings in 2/98 (2%) cases, and no major changes in patient management related to imaging findings occurred over this period, resulting in almost $500000 cost without significant patient benefit. We distributed these results to the Family Medicine department and clinics that frequently placed this order. An approximately 83% drop in ordering rate occurred over the ensuing 3 mo follow-up period. Sacrum MR imaging for low back pain and tail bone pain has not been a cost-effective diagnostic tool at our institution. Physician education was a useful tool in reducing overutilization of this study, with a remarkable drop in such studies after sharing these findings with primary care physicians at the institution. In conclusion, sacrum MR imaging rarely elucidates the cause of low back/tail pain diagnosed in a primary care setting and is even less likely to result in major changes in management. The practice can be adopted in other institutions for the benefit of their patients and improve cost efficiency.
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http://dx.doi.org/10.5662/wjm.v11.i4.110DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8299904PMC
July 2021

Osseous Tumor Reporting and Data System-Multireader Validation Study.

J Comput Assist Tomogr 2021 Jul-Aug 01;45(4):571-585

Department of Orthopedic Surgery, UT Southwestern Medical Center, Dallas, TX.

Objective: To develop and validate an Osseous Tumor Reporting and Data System (OT-RADS) with the hypothesis that the proposed guideline is reliable and assists in separating benign from malignant osseous tumors with a good area under the curve, and that could assist further patient management.

Methods: In this multireader cross-sectional validation study, an agreement was reached for OT-RADS categories based on previously described magnetic resonance imaging features and consensus of expert musculoskeletal radiologists. World Health Organization classification was used, and a wide spectrum of benign and malignant osseous tumors was evaluated. Magnetic resonance imaging categories were as follows: OT-RADS 0-incomplete imaging; OT-RADS I-negative; OT-RADS II-definitely benign; OT-RADS III-probably benign; OT-RADS IV-suspicious for malignancy or indeterminate; OT-RADS V-highly suggestive of malignancy; and OT-RADS VI-known biopsy-proven malignancy or recurrent malignancy in the tumor bed. Four blinded readers categorized each tumor according to OT-RADS classification. Intraclass correlation (ICC) and Conger κ were used. Diagnostic performance measures including area under the receiver operating curve were reported. Osseous Tumor Reporting and Data System was dichotomized as benign (I-III) and malignant (IV and V) for calculating sensitivity and specificity.

Results: Interreader agreement for OT-RADS (ICC = 0.78) and binary distinction of benign versus malignant (κ = 0.67) were good to excellent, while agreement for individual tumor feature characteristics were poor to fair (ICC = 0.25-0.36; κ = 0.16-0.39). The sensitivities, specificities, and area under the receiver operating curve of the readers ranged from 0.93-1.0, 0.71-0.86, and 0.92-0.97, respectively.

Conclusions: Osseous Tumor Reporting and Data System lexicon is reliable and helps stratify tumors into benign and malignant categories. It can be practically used by radiologists to guide patient management, improve multidisciplinary communications, and potentially impact outcomes.
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http://dx.doi.org/10.1097/RCT.0000000000001184DOI Listing
July 2021

3T Magnetic Resonance Imaging of the Wrist Tendons.

Top Magn Reson Imaging 2020 Oct;29(5):221-235

Division of Musculoskeletal Imaging and Intervention, Department of Radiology, University of Washington, Seattle, WA.

Magnetic resonance imaging (MRI) is frequently used in the imaging evaluation of wrist pain. The complex anatomy of the wrist can be demonstrated by MRI. Three tesla (3 T) MRI offers increased signal-to-noise ratio relative to 1.5 T MRI allowing for higher soft tissue contrast and better spatial resolution. The resulting increase in conspicuity of fine anatomic detail may improve the detection and characterization of wrist pathology. In this article, we will review the anatomy, normal variants, and common pathologies of the wrist tendons as evaluated on 3 T MRI.
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http://dx.doi.org/10.1097/RMR.0000000000000255DOI Listing
October 2020

Corrigendum to "Three tesla and 3D multiparametric combined imaging evaluation of axial spondyloarthritis and pelvic enthesopathy" [Eur. J. Radiol. (2020) 108916].

Eur J Radiol 2020 Nov 18;132:109260. Epub 2020 Sep 18.

Division of Musculoskeletal Radiology, Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States.

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http://dx.doi.org/10.1016/j.ejrad.2020.109260DOI Listing
November 2020

Three-dimensional and 3-Tesla MRI morphometry of knee meniscus in normal and pathologic state.

Clin Anat 2021 Jan 23;34(1):143-153. Epub 2020 Sep 23.

Radiology, UT Southwestern Medical Center, Dallas, Texas, USA.

Introduction: To conduct a morphometric analysis of intact and torn menisci using isotropic meniscus plane three-dimensional (3D) reconstructions on 3-Tesla MRI and compare 2D versus 3D MRI for meniscus tear characterization.

Materials And Methods: One hundred thirty three normal menisci from 92 patients (39 male, 53 female), and 38 arthroscopy-proven torn menisci from 36 patients (23 male, 13 female) were evaluated using 3D isotropic multi-planar MRI reconstructions and 2D MRI. Two observers measured the tibial plateau height and area, meniscal height, axial plane cross-sectional areas, and extrusion of intact menisci. Two observers also measured the meniscal tear length, tear area, and residual area of pathological menisci on 2D and 3D MRI. Intraclass correlation coefficients (ICC) were obtained. Institutional Review Board approval was obtained, and the informed consent was waived.

Results: Medial meniscus (MM) and lateral meniscus (LM) areas were 503.6 ± 85.1 mm and 396.6 ± 72.0 mm for Observer 1, and 515.8 ± 82.1 mm and 408.0 ± 68.3 mm for Observer 2 (ICC:0.86, 0.87). In torn menisci, average tear length, area, and residual area were 36.3 ± 13.6 mm, 182.6 ± 139.3 mm , and 235.4 ± 140.3 mm , respectively for Observer 1, and 38.9 ± 14.7 mm, 181.2 ± 135.6 mm , 238.2 ± 140.5 mm for Observer 2. In the MM and LM, bucket-handle and complex tears were largest in areas, respectively. ICCs were excellent (0.91-1.0) on 3D MRI and moderate-good (0.57-0.81) on 2D MRI.

Conclusion: Meniscus morphometry on 3D MRI shows moderate to excellent inter-observer reliability and meniscus tear extent is more reliably defined on 3D MRI than 2D MRI. Residual meniscus-area calculation can be performed on 3D MRI.
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http://dx.doi.org/10.1002/ca.23679DOI Listing
January 2021

Three tesla and 3D multiparametric combined imaging evaluation of axial spondyloarthritis and pelvic enthesopathy.

Eur J Radiol 2020 May 6;126:108916. Epub 2020 Mar 6.

Department of Radiology, United States.

Purpose: Axial spondyloarthritis (SpA) is a group of diseases with temporally disseminated symptoms and clinical signs, which render the diagnosis challenging. Laboratory and MRI findings are used in addition for confirming the diagnosis and evaluation of disease activity. The purpose of this study was to evaluate clinically suspected axial SpA to determine the technical success of a multiparametric and 3D rheumatology lumbosacral MR imaging (MRLI) protocol and to assess the disease distribution, inter-reader reliability, and impact on patient management.

Methods: A consecutive series of patients with clinical suspicion of axial SpA were included. Two rheumatologists recorded the clinical findings and disease activity on a confidence scale before and after MRLI. Two musculoskeletal (MSK) radiologists read the imaging data including enthesitis, arthritis, osseous lesions, ADC values, and enhancement. Prevalence-adjusted and bias-adjusted kappa (PABAK), ICC and Fisher exact test were calculated.

Results: There were 41 patients including 31 females and 10 males with ages of 41 ± 10 and 41 ± 12 (mean ± SD), respectively. The spine T2W imaging received the highest quality scores followed by whole abdomen-pelvis 3D-T2W imaging, 3D-CEMR (contrast-enhanced MRI), and DWI. On spine imaging, acute and chronic lesions of lumbar spine and sacroiliac joints were seen in 4/41, 18/41 and 6/41, and 27/41 of the patients, respectively. Several additional enthesopathy lesions were seen on the whole abdomen-pelvis 3D sequence. ADC value of bone lesions was different 0.95 ± 0.23 (mean ± SD) than normal bone (0.20 ± 0.1). PABAK for acute and chronic findings ranged 0.70-1.0 and 0.41-0.51, respectively. Imaging changed the diagnosis in 17 of 41 patients. No association was noted with respect to treatment change (p = 1) or clinical response (p = 0.2).

Conclusion: Multiparametric lumbosacral MR imaging is a technically successful modality to identify multiple spinal and additional extraspinal sites of involvement in SpA, which are helpful in establishing the diagnosis of axial SpA. Larger patient population study is warranted to evaluate further impact on the treatment efficacy.
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http://dx.doi.org/10.1016/j.ejrad.2020.108916DOI Listing
May 2020

Correction to: Qualitative and quantitative analysis of glenoid bone stock and glenoid version: inter-reader analysis and correlation with rotator cuff tendinopathy and atrophy in patients with shoulder osteoarthritis.

Skeletal Radiol 2020 Jun;49(6):995-1003

Radiology, UT Southwestern Medical Center, Dallas, TX, USA.

Purpose Glenoid bone stock and morphology and rotator cuff muscle quality and tendon integrity affect the outcome of total shoulder arthroplasty. We hypothesized that glenoid bone loss correlates with rotator cuff muscle fatty infiltration (FI), tendinopathy, and atrophy.Design Forty-three 3-D CT scans and MRIs of 43 patients (mean age 62 years; SD 13 years; range 22-77 years) referred for primary shoulder pain were evaluated. Measurements of glenoid bone stock, version, and posterior humeral subluxation index (HSI) were assessed on an axial CT image reconstructed in the true scapular plane. Measurements utilized the Friedman line to approximate the pre-pathologic surface. Glenoid morphology was assigned by modified Walch classification. Rotator cuff FI, atrophy, and tendon integrity were assessed on corresponding MRIs.Results There was a very strong negative correlation between increasing glenoid version and HSI (r = - 0.908; p < 0.0001). There was a moderately negative correlation between anterior bone loss and HSI (r = - 0.562; p < 0.0001) and a moderately positive correlation between posterior bone loss and HSI (r = 0.555; p < 0.0001). Subscapularis muscle FI correlated moderately with increased anterior and central bone loss and increased humeral head medialization (r = 0.512, p = 0.0294; r = 0.479, p = 0.033; r = 0.494, p = 0.0294, respectively). Inter-observer reliability (intra-class correlation coefficient [ICC] and kappa) was good to excellent for all measurements and grading.Conclusion Glenoid anteversion and anterior and posterior bone loss are associated with varying HSI. Subscapularis muscle FI, not tendon integrity, correlates to anterior and central glenoid erosion. The study adds evidence that neither rotator cuff tendinopathy nor muscle atrophy exhibits a significant relationship to HSI.
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http://dx.doi.org/10.1007/s00256-020-03386-zDOI Listing
June 2020

Qualitative and quantitative analysis of glenoid bone stock and glenoid version: inter-reader analysis and correlation with rotator cuff tendinopathy and atrophy in patients with shoulder osteoarthritis.

Skeletal Radiol 2020 Jun 18;49(6):985-993. Epub 2020 Jan 18.

Radiology, UT Southwestern Medical Center, Dallas, TX, USA.

Purpose: Glenoid bone stock and morphology and rotator cuff muscle quality and tendon integrity affect the outcome of total shoulder arthroplasty. We hypothesized that glenoid bone loss correlates with rotator cuff muscle fatty infiltration (FI), tendinopathy, and atrophy.

Design: Forty-three 3D CT scans and MRIs of 43 patients (mean age 62 years; SD 13 years; range 22-77 years) referred for primary shoulder pain were evaluated. Measurements of glenoid bone stock, version, and posterior humeral subluxation index (HSI) were assessed on an axial CT image reconstructed in the true scapular plane. Measurements utilized the Friedman line to approximate the pre-pathologic surface. Glenoid morphology was assigned by modified Walch classification. Rotator cuff FI, atrophy, and tendon integrity were assessed on corresponding MRIs.

Results: There was a very strong negative correlation between increasing glenoid version and HSI (r = - 0.908; p < 0.0001). There was a moderately negative correlation between anterior bone loss and HSI (r = - 0.562; p < 0.0001) and a moderately positive correlation between posterior bone loss and HSI (r = 0.555; p < 0.0001). Subscapularis muscle FI correlated moderately with increased anterior and central bone loss and increased humeral head medialization (r = 0.512, p = 0.0294; r = 0.479, p = 0.033; r = 0.494, p = 0.0294; respectively). Inter-observer reliability (intra-class correlation coefficient [ICC] and kappa) was good to excellent for all measurements and grading.

Conclusion: Glenoid anteversion and anterior and posterior bone loss are associated with varying HSI. Subscapularis muscle FI, not tendon integrity, correlates to anterior and central glenoid erosion. The study adds evidence that neither rotator cuff tendinopathy nor muscle atrophy exhibits a significant relationship to HSI.
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http://dx.doi.org/10.1007/s00256-020-03377-0DOI Listing
June 2020

Advanced MR imaging of bone marrow: quantification of signal alterations on T1-weighted Dixon and T2-weighted Dixon sequences in red marrow, yellow marrow, and pathologic marrow lesions.

Skeletal Radiol 2020 Apr 12;49(4):541-548. Epub 2019 Oct 12.

Radiology Department, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.

Objectives: To quantify and compare signal intensity (SI) changes on T1-weighted (W) and T2W Dixon imaging in yellow marrow, red marrow, and bone marrow lesions.

Materials And Methods: A total of 141 patients (77 controls, 64 lesions-33 benign, 31 malignant) between January 2016 and December 2017 were retrospectively identified. For the control group, fixed 2-cm region of interests (ROI) were drawn at L5, bilateral ilium and femurs on in-phase and opposed-phase T1W and T2W Dixon images. For the lesion group, ROIs of best fit were drawn around each lesion on in-phase and opposed-phase T2W Dixon images. SI changes between in-phase and opposed phase maps for each group were compared. Inter-reader analysis was performed.

Results: Yellow marrow exhibited smaller SI changes as compared to red marrow on both T1W and T2W Dixon imaging at all locations (p < 0.0001) except at L5 on T2W Dixon imaging (p = 0.206). Both benign and malignant lesions showed significantly smaller SI changes as compared to both yellow (p = 0.0087, p < 0.0001) and red marrow (p = 0.0004, p < 0.0001) on T2W Dixon imaging. Malignant lesions exhibited smaller SI change as compared to benign lesions on T2W Dixon imaging (p = 0.0005). Signal intensity loss on both red and yellow marrow were smaller on T1W Dixon as compared to T2W Dixon (0.49-0.64, 0.27-0.31 vs. 0.70-0.74, 0.48-0.71). Inter-reader agreements were excellent (0.91-0.97).

Conclusions: SI change calculated from T2-weighted Dixon imaging can adequately differentiate between yellow marrow, red marrow, and osseous lesions, both benign and malignant.
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http://dx.doi.org/10.1007/s00256-019-03303-zDOI Listing
April 2020

Dose Reduction for Upper Extremity CT.

J Am Coll Radiol 2019 May 7;16(5):733-736. Epub 2019 Feb 7.

Radiology Department, UT Southwestern Medical Center, Dallas, Texas.

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http://dx.doi.org/10.1016/j.jacr.2018.11.032DOI Listing
May 2019

Subacromial impingement anatomy and its association with rotator cuff pathology in women: radiograph and MRI correlation, a retrospective evaluation.

Skeletal Radiol 2019 May 27;48(5):781-790. Epub 2018 Oct 27.

Radiology Department, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9178, USA.

Objective: To evaluate the relationships between acromial anatomy and developmental alterations with rotator cuff tears in female patients and compare these parameters on radiographs and corresponding MRIs along with inter-reader performance.

Materials And Methods: Patient demographics, symptoms, and acromial characteristics on radiograph (acromial index, lateral acromion angle, subacromial space on AP and Y- views, acromial anterior and lateral downsloping) and MRI (shape, slope, spur, osteoarthrosis, os acromiale) were recorded. Radiographic and MRI findings were compared and correlated with rotator cuff pathology on MRI. Inter-reader analysis was performed.

Results: A total of 140 MRIs from 137 female patients were included. No significant correlation (p > 0.05) existed between acromial parameters and rotator cuff tears, except for a smaller subacromial space on the Y view and spurs correlated with subscapularis tendon tear (p = 0.02, p = 0.04). The presence of lateral downsloping on MRI correlated with a smaller lateral acromion angle (p = 0.0002) and the presence of lateral downsloping on radiography (p = 0.0015). Inter-reader agreements were good to excellent (ICC: 0.65-0.89).

Conclusion: Subacromial impingement anatomy characteristics have no significant associations with supraspinatus or infraspinatus tears in symptomatic women. Among different measures, supine MRI can be reliably used to identify lateral downsloping of the acromion.
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http://dx.doi.org/10.1007/s00256-018-3096-0DOI Listing
May 2019

Frequency Offset Corrected Inversion Pulse for B and B Insensitive Fat Suppression at 3T: Application to MR Neurography of Brachial Plexus.

J Magn Reson Imaging 2018 10 15;48(4):1104-1111. Epub 2018 Sep 15.

Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.

Background: The 3D short tau inversion recovery (STIR) sequence is routinely used in clinical MRI to achieve robust fat suppression. However, the performance of the commonly used adiabatic inversion pulse, hyperbolic secant (HS), is compromised in challenging areas with increased B and B inhomogeneities, such as brachial plexus at 3T.

Purpose: To demonstrate the frequency offset corrected inversion (FOCI) pulse as an efficient fat suppression STIR pulse with increased robustness to B and B inhomogeneities at 3T, compared to the HS pulse.

Study Type: Prospective.

Subjects/phantom: Initial evaluation was performed in phantoms and one healthy volunteer by varying the B field, while subsequent comparison was performed in three healthy volunteers and five patients without varying the B .

Field Strength/sequence: 3T; 3D TSE-STIR with HS and FOCI pulses.

Assessment: Brachial plexus images were qualitatively evaluated by two musculoskeletal radiologists independently using a four-point grading scale for fat suppression, shading artifacts, and nerve visualization.

Statistical Test: The Wilcoxon signed-rank test with P < 0.05 was considered statistically significant.

Results: Simulations and phantom experiments demonstrated broader bandwidth (2.5 kHz vs. 0.83 kHz, increased B robustness) at the same adiabatic threshold and lower adiabatic threshold (5 μT vs. 7 μT at 3.5 ppm, increased B robustness) at the same bandwidth with the FOCI pulse compared to the HS pulse With increased bandwidth, the FOCI pulse achieved robust fat suppression even at 50% of maximum B strength, while the HS pulse required >75% of maximum B strength. Compared to the standard 3D TSE-STIR with HS pulse, the FOCI pulse achieved uniform fat suppression (P < 0.05), better nerve visualization (P < 0.05), and minimal shading artifacts (P < 0.01) in brachial plexus at 3T.

Data Conclusion: The FOCI pulse has increased robustness to B and B inhomogeneities, compared to the HS pulse, and enables uniform fat suppression in brachial plexus at 3T.

Level Of Evidence: 1 Techinical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:1104-1111.
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http://dx.doi.org/10.1002/jmri.26021DOI Listing
October 2018

Role of chemical shift and Dixon based techniques in musculoskeletal MR imaging.

Eur J Radiol 2017 Sep 16;94:93-100. Epub 2017 Jun 16.

UT Southwestern Medical Center, Dallas, TX, USA.

Fat suppression technique is a valuable resource in musculoskeletal magnetic resonance (MR) imaging that is helpful in the diagnosis and differentiation of various pathologies. Multiple different techniques are available for fat suppression, including frequency selective pulse sequence, inversion recovery, hybrid technique, chemical shift imaging (CSI) and the related Dixon based approach. The utility of CSI and Dixon approach is not well recognized in the domain of musculoskeletal MR imaging. The aim of this article is to review the various options for fat suppression and present focused discussion of the role of CSI and Dixon techniques for musculoskeletal MR imaging.
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http://dx.doi.org/10.1016/j.ejrad.2017.06.011DOI Listing
September 2017

Cross-sectional imaging of adult crystal and inflammatory arthropathies.

Skeletal Radiol 2016 Sep 21;45(9):1173-91. Epub 2016 May 21.

Musculoskeletal Radiology and Orthopaedic Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9178, USA.

This article highlights the key aspects and current perspectives of the role of cross-sectional imaging in adult crystal and inflammatory arthropathies in adults, briefly discussing CT, and particularly focusing on MRI and US imaging as it supplements the conventional radiography. The role of conventional and advanced MR imaging techniques and imaging findings in this domain is discussed and illustrated with case examples. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article contains images and data, which were collected from patients as a part of a retrospective IRB from the institutional teaching files and informed consent was waived.
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http://dx.doi.org/10.1007/s00256-016-2402-yDOI Listing
September 2016

MR imaging of skeletal muscle signal alterations: Systematic approach to evaluation.

Eur J Radiol 2016 May 8;85(5):922-35. Epub 2016 Feb 8.

Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States. Electronic address:

Muscle edema or edema-like signal alterations are commonly encountered findings in musculoskeletal magnetic resonance (MR) imaging. Although such signal alterations are very sensitive for detection of the underlying muscle pathology, these are often non-specific findings. Encompassing knowledge of their typical clinical presentations, characteristic appearances and patterns of muscle signal alterations and following a systematic approach towards their assessment, a reader can effectively narrow down the differential diagnosis. This article outlines the role of conventional imaging and advanced anatomic and functional musculoskeletal MR imaging techniques in the evaluation of various muscle disorders and presents a systematic approach towards their diagnosis and management.
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http://dx.doi.org/10.1016/j.ejrad.2016.02.007DOI Listing
May 2016

Preliminary experience with intravenous gadoxetate disodium as a craniospinal MR contrast agent.

Eur J Radiol 2015 Dec 15;84(12):2539-47. Epub 2015 Sep 15.

University of Minnesota-Fairview and Hennepin County Medical Centers, Minneapolis, MN, United States.

Introduction: Gadoxetate disodium is a gadolinium-based contrast agent (GBCA) typically used for body imaging, as about 50% of its excretion is via the liver. Its use for craniospinal MRI has not been reported.

Materials And Methods: Over a 3 years period, 31 adults underwent postcontrast MRI using gadoxetate disodium, each of whom had a relative contraindication to a GBCA, but a GBCA was deemed necessary by the clinical service to direct therapy. Postcontrast T1WI included either gradient-echo (GET1WI, n=12) or spin-echo (SET1WI, n=13) imaging. The contraindication in 29 patients was stage 3-5 chronic kidney disease (CKD) or acute kidney injury (AKI); the other two had normal kidney function, but a history of a reaction to another GBCA (vomiting in one and hypersensitivity in the other). Over a 3 years period, in those patients in whom a GBCA was both deemed necessary and had an estimated GFR (eGFR) of <40 ml/min/1.73 m(2) (i.e., stage 3-5 CKD), both informed consent and nephrology consultation was obtained. A 10 ml dose was given for cranial (n=23), spinal (n=9), and neck/face MRI (n=3), as well as craniocervical MRA (n=6). Three neuroradiologists separately evaluated for normal enhancement in 11 structures. The contrast enhancing percentage (CE%) was measured in 3 structures, and in enhancing lesions, if present.

Results: The pre-MRI eGFR was not significantly different from that at 30-90 days (p=0.522) in the 23 patients with an available eGFR at >90 days post-MRI; no patients developed acute kidney injury post-MRI, nor nephrogenic systemic fibrosis. Of the 11 intracranial structures scored, the superior sagittal sinus, pituitary stalk, and atrial choroid plexus enhanced in all 23 patients who underwent brain MRI, with CE%'s of 171.0%, 73.0%, and 69.8%, respectively. The number of patients with enhancing lesions were 3/23 brain MRI's, 8/9 spinal MRI's, 3/3 neck MRI's, and 2/6 craniocervical MRA/MRV's. In 9 spinal MRI's, the basivertebral plexus CE% was 213.7%; in the 7 with spondylodiscitis, the CE% measured 125.8% in enhancing epidural tissue, with a contrast-to-noise ratio (CNR) of 98.0%.

Conclusion: This preliminary report describes the use of gadoxetate disodium as an alternative GBCA for craniospinal MRI and MRA in the renally impaired, but its efficacy in this regard must be further evaluated prospectively.
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http://dx.doi.org/10.1016/j.ejrad.2015.09.004DOI Listing
December 2015

T2 black lesions on routine knee MRI: differential considerations.

Eur Radiol 2016 Jul 29;26(7):2387-99. Epub 2015 Sep 29.

Musculoskeletal Radiology, UT Southwestern Medical Center, Dallas, TX, USA.

The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. Key Points • Hypointense lesions on T2 images (T2 Dark Lesions) encompass limited diagnostic possibilities. • T2 Dark lesions often show characteristic appearances and predilections in the knee. • A systematic diagnostic approach will help radiologists make the correct diagnosis.
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http://dx.doi.org/10.1007/s00330-015-4027-2DOI Listing
July 2016

Spinal diffusion tensor imaging: a comprehensive review with emphasis on spinal cord anatomy and clinical applications.

Clin Anat 2015 01 4;28(1):88-95. Epub 2014 Feb 4.

Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, Alabama.

Magnetic resonance imaging technology allows for in vivo visualization of fiber tracts of the central nervous system using diffusion-weighted imaging sequences and data processing referred to as "diffusion tensor imaging" and "diffusion tensor tractography." While protocols for high-fidelity diffusion tensor imaging of the brain are well established, the spinal cord has proven a more difficult target for diffusion tensor methods. Here, we review the current literature on spinal diffusion tensor imaging and tractography with special emphasis on neuroanatomical correlations and clinical applications.
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http://dx.doi.org/10.1002/ca.22349DOI Listing
January 2015

Augmenting the impact of technology adoption with financial incentive to improve radiology report signature times.

J Am Coll Radiol 2010 Mar;7(3):198-204

Center for Evidence-Based Imaging, Brookline, Massachusetts 02445, USA.

Purpose: Radiology report signature time (ST) can be a substantial component of total report turnaround time. Poor turnaround time resulting from lengthy ST can adversely affect patient care. The combination of technology adoption with financial incentive was evaluated to determine if ST improvement can be augmented and sustained.

Methods: This prospective study was performed at a 751-bed, urban, tertiary care adult teaching hospital. Test-site imaging volume approximated 48,000 examinations per month. The radiology department has 100 trainees and 124 attending radiologists serving multiple institutions. Over a study period of 4 years and 4 months, three interventions focused on radiologist signature performance were implemented: 1) a notification paging application that alerted radiologists when reports were ready for signature, 2) a picture archiving and communications systems (PACS)-integrated speech recognition report generation system, and 3) a departmental financial incentive to reward radiologists semiannually for ST performance. Signature time was compared before and after the interventions. Wilcoxon and linear regression statistical analyses were used to assess the significance of trends.

Results: Technology adoption (paging plus speech recognition) reduced median ST from >5 to <1 hour (P < .001) and 80th-percentile ST from >24 to 15 to 18 hours (P < .001). Subsequent addition of a financial incentive further improved 80th-percentile ST to 4 to 8 hours (P < .001). The gains in median and 80th-percentile ST were sustained over the final 31 months of the study period.

Conclusions: Technology interventions coupled with financial incentive can result in synergistic and sustainable improvement in radiologist report-signing behavior. The addition of a financial incentive leads to better performance than that achievable through technology alone.
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http://dx.doi.org/10.1016/j.jacr.2009.11.011DOI Listing
March 2010

Bipolar supernumerary renal artery.

Surg Radiol Anat 2007 Feb 24;29(1):89-92. Epub 2006 Oct 24.

Department of Radiology and Angiography, Tabriz University of Medical Sciences, Tabriz, Iran.

The variations of renal arteries are considered critical issues that surgeons should have thorough envision and appreciation of the condition. Variations of these vessels may influences urological, renal transplantation and laparoscopic surgeries. We present a case of bilateral accessory renal artery with a striking pre-hilar branching pattern encountered upon digital subtraction angiography (DSA) for imaging of the renal arteries of a healthy 30-year-old man, renal transplant donor. The right kidney received two renal arteries from the aorta including a main hilar and one lower polar. However, the left accessory artery while originated from the aorta, simultaneously, supplied both upper and lower renal poles following its pre-hilar division that replaced upper/apical and lower segmental arteries of the single main renal artery, respectively. The left main renal artery divided into two anterior and posterior segmental arteries. Whether this should be categorized either as an accessory hilar artery or a unique variant of renal arterial supply, the so-called bipolar supernumerary renal artery, is a matter of debate. We discuss possible embryologic origin and clinical aspects of accessory renal artery.
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http://dx.doi.org/10.1007/s00276-006-0158-0DOI Listing
February 2007

Usefulness of 18F-FDG PET-directed skeletal biopsy for metastatic neoplasm.

Acad Radiol 2006 Aug;13(8):1011-5

Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.

Rationale And Objectives: Technium-99m methylene diphosphonate (99mTc-MDP) bone scintigraphy and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) are useful imaging modalities to detect skeletal metastases. Several other conditions such as infection, fractures, and arthritis can cause false-positive results with either modality. However, PET is felt to be more specific than bone scintigraphy for malignancy. Our objective was to investigate the value of PET scan compared with bone scintigraphy for directing biopsies in patients with suspected metastatic bone lesions.

Materials And Methods: Retrospective case series of subjects with undergoing skeletal biopsy of suspected metastases detected by 99mTc-MDP scintigraphy or 18F-FDG PET scan. Reference standards were pathologic reports and follow-up for 6 months. The diagnostic test performance measures of true positive (TP), false positive (FP), and positive predictive value (PPV) were calculated for each group. The PPV with 95% confidence intervals (CI) was compared using the Fisher exact test.

Results: There were a total of 68 subjects. PET-directed skeletal biopsies (n = 39) showed 35 TP, 4 FP, and an 89.7% PPV (95% CI: 75.7-97.1%). Bone scintigraphy directed biopsies (n = 29) had 21 TP, 8 FP, and 72.4 % PPV (95% CI: 52.7-82.7%). The PPV was not significantly different between the groups (P = .10).

Conclusion: This study supports that PET can be used to effectively direct bone biopsies to confirm metastatic neoplasm and suggests that PET may provide incremental improvement to diagnostic yield over bone scintigraphy. The role of PET compared with bone scintigraphy for directing skeletal biopsies warrants further verification.
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http://dx.doi.org/10.1016/j.acra.2006.05.005DOI Listing
August 2006
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