Faculty Bibliography
Searched for:
in-biosketch:yes
person:babbj01
Total Results:
548
MAGMA (European Society for Magnetic Resonance in Medicine & Biology). 2017:30(3):281-289.DOI: 10.1007/s10334-016-0605-9
A low-cost Mr compatible ergometer to assess post-exercise phosphocreatine recovery kinetics
OBJECTIVE: To develop a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems to reliably quantify metabolic parameters in human lower leg muscle using phosphorus magnetic resonance spectroscopy. MATERIALS AND METHODS: We constructed an MR compatible ergometer using commercially available materials and elastic bands that provide resistance to movement. We recruited ten healthy subjects (eight men and two women, mean age +/- standard deviation: 32.8 +/- 6.0 years, BMI: 24.1 +/- 3.9 kg/m2). All subjects were scanned on a 7 T whole-body magnet. Each subject was scanned on two visits and performed a 90 s plantar flexion exercise at 40% maximum voluntary contraction during each scan. During the first visit, each subject performed the exercise twice in order for us to estimate the intra-exam repeatability, and once during the second visit in order to estimate the inter-exam repeatability of the time constant of phosphocreatine recovery kinetics. We assessed the intra and inter-exam reliability in terms of the within-subject coefficient of variation (CV). RESULTS: We acquired reliable measurements of PCr recovery kinetics with an intra- and inter-exam CV of 7.9% and 5.7%, respectively. CONCLUSION: We constructed a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems, which allowed us to quantify reliably PCr recovery kinetics in lower leg muscle using 31P-MRS.
PMCID:5441940
PMID: 28054143
ISSN: 1352-8661
CID: 2386752
Comparative performance of non-contrast MRI with HASTE vs. contrast-enhanced MRI/3D-MRCP for possible choledocholithiasis in hospitalized patients
PURPOSE: To compare the performance of non-contrast MRI with half-Fourier acquisition single-shot turbo spin echo (HASTE) vs. contrast-enhanced MRI/3D-MRCP for assessment of suspected choledocholithiasis in hospitalized patients. METHODS AND MATERIALS: 123 contrast-enhanced abdominal MRI/MRCP scans in the hospital setting for possible choledocholithiasis were retrospectively evaluated. Endoscopic retrograde cholangiopancreatography, intraoperative cholangiogram or documented clinical resolution served as the reference standard. Readers first evaluated the biliary tree using coronal and axial HASTE and other non-contrast sequences, and later reviewed the entire exam with post-contrast sequences and 3D-MRCP. Test performance for the image sets was compared for choledocholithiasis, acute hepatitis, cholangitis, and acute cholecystitis. Reader agreement, MRCP image quality, and confidence levels were also assessed. Clinical predictors of age and fever were tested for association with perceived need for contrast in biliary assessment. RESULTS: There were 27 cases of choledocholithiasis, 31 cases of acute hepatitis, 37 cases of acute cholecystitis, and 3 clinically diagnosed cases of acute cholangitis. Both the abbreviated and full contrast-enhanced/MRCP image sets resulted in high accuracy for choledocholithiasis (91.1-94.3% vs. 91.9-92.7%). There was no difference in sensitivity or specificity for either reader for any diagnosis between image sets (p > 0.40). 1 reader showed improved confidence (p < 0.001) with inclusion of MRCP and contrast-enhanced images, but neither confidence nor MRCP quality scores were associated with diagnostic accuracy. Patient age and fever did not predict the need for contrast-enhanced images. CONCLUSION: In hospitalized patients with suspected choledocholithiasis, performance of non-contrast abdominal MRI with HASTE is similar to contrast-enhanced MRI with 3D-MRCP, offering potential for decreased scanning time and improved patient tolerability.
PMCID:5457321
PMID: 28154911
ISSN: 2366-0058
CID: 2437032
Visualization of the normal appendix in children on MRI using radial vibe - A contrast enhanced, free-breathing, radially sampled, 3D T1-weighted, gradient-echo sequence [Meeting Abstract]
Disclosures: All authors have disclosed no financial interests, arrangements or affiliations in the context of this activity. Purpose or Case Report: Current MRI evaluation of appendicitis is limited by duration of examination and patient cooperation. The radially sampled 3D T1 weighted, gradient recalled echo sequence (radial VIBE) is a free-breathing, motion robust sequence that may prove useful in the evaluation of appendicitis in children. The purpose of this investigation is to determine the detection rate of the normal appendix with contrast enhanced (CE) radial VIBE alone compared with CE conventional 3D gradient recalled echo volumetric interpolated breath-hold examination (conventional VIBE) alone and multi-sequence abdominal pelvic MRI including CE radial VIBE. Methods& Materials:We conducted a retrospective, HIPAA compliant and IRB approved study of patients between 7 and 18 years of age who underwent an abdominal and pelvic contrast enhanced MRI between January 1, 2012 and April 1, 2016. Patients with active right lower quadrant inflammation, pelvic masses, or history of appendectomy were excluded. Visualization of the appendix was assessed by two pediatric radiologists with Certificates of Added Qualification by consensus on the following sequences: CE radial VIBE only, CE conventional VIBE only, and multi-sequence MRI which included CE radial VIBE and at least an axial or coronal single shot fast spin echo (SSFSE) or axial T2 weighted spin echo with fat suppression. The detection rates of the appendix for each sequence or combination of sequences were compared with a McNemar test. Results: Ninety-six patients met inclusion criteria. The detection rate of the normal appendix on CE radial VIBE was significantly higher than on CE conventional VIBE (76% vs 57.3%, p=0.003). The detection rate of the normal appendix with multi-sequence MRI was significantly higher than on CE conventional VIBE (81.3% vs 57%, p<0.001). There was no significant difference between the detection rate of the normal appendix on CE radial VIBE and multi-sequence MRI (76% vs 81.3%, p=0.267). When the appendix was not visualized on the CE radial VIBE (n=23) but detected on the multi-sequence MRI (n=9), it was most often visualized on SSFSE (n=8). Conclusions: CE radial VIBE allows superior detection of the normal appendix compared to CE conventional VIBE. The detection rate of the normal appendix on CE radial VIBE alone is nearly as good as when the CE radial VIBE is interpreted with additional sequences
EMBASE:615734017
ISSN: 1432-1998
CID: 2550212
Dynamic contrast-enhanced MRI of the prostate: An intraindividual assessment of the effect of temporal resolution on qualitative detection and quantitative analysis of histopathologically proven prostate cancer
PURPOSE: To assess the effects of temporal resolution (RT ) in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on qualitative tumor detection and quantitative pharmacokinetic parameters in prostate cancer. MATERIALS AND METHODS: This retrospective Institutional Review Board (IRB)-approved study included 58 men (64 +/- 7 years). They underwent 3T prostate MRI showing dominant peripheral zone (PZ) tumors (24 with Gleason >/= 4 + 3), prior to prostatectomy. Continuously acquired DCE utilizing GRASP (Golden-angle RAdial Sparse Parallel) was retrospectively reconstructed at RT of 1.4 sec, 3.7 sec, 6.0 sec, 9.7 sec, and 14.9 sec. A reader placed volumes-of-interest on dominant tumors and benign PZ, generating quantitative pharmacokinetic parameters (ktrans , ve ) at each RT . Two blinded readers assessed each RT for lesion presence, location, conspicuity, and reader confidence on a 5-point scale. Data were assessed by mixed-model analysis of variance (ANOVA), generalized estimating equation (GEE), and receiver operating characteristic (ROC) analysis. RESULTS: RT did not affect sensitivity (R1all : 69.0%-72.4%, all Padj = 1.000; R1GS>/=4 + 3 : 83.3-91.7%, all Padj = 1.000; R2all : 60.3-69.0%, all Padj = 1.000; R2GS>/=4 + 3 : 58.3%-79.2%, all Padj = 1.000). R1 reported greater conspicuity of GS >/= 4 + 3 tumors at RT of 1.4 sec vs. 14.9 sec (4.29 +/- 1.23 vs. 3.46 +/- 1.44; Padj = 0.029). No other tumor conspicuity pairwise comparison reached significance (R1all : 2.98-3.43, all Padj >/= 0.205; R2all : 2.57-3.19, all Padj >/= 0.059; R1GS>/=4 + 3 : 3.46-4.29, all other Padj >/= 0.156; R2GS>/=4 + 3 : 2.92-3.71, all Padj >/= 0.439). There was no effect of RT on reader confidence (R1all : 3.17-3.34, all Padj = 1.000; R2all : 2.83-3.19, all Padj >/= 0.801; R1GS>/=4 + 3 : 3.79-4.21, all Padj = 1.000; R2GS>/=4 + 3 : 3.13-3.79, all Padj = 1.000). ktrans and ve of tumor and benign tissue did not differ across RT (all adjusted P values [Padj ] = 1.000). RT did not significantly affect area under the curve (AUC) of Ktrans or ve for differentiating tumor from benign (all Padj = 1.000). CONCLUSION: Current PI-RADS recommendations for RT of 10 seconds may be sufficient, with further reduction to the stated PI-RADS preference of RT
PMCID:5538355
PMID: 27649481
ISSN: 1522-2586
CID: 2254782
Proposed Adjustments to PI-RADS Version 2 Decision Rules: Impact on Prostate Cancer Detection
Purpose To test the impact of existing Prostate Imaging Reporting and Data System (PI-RADS) version 2 (V2) decision rules, as well as of proposed adjustments to these decision rules, on detection of Gleason score (GS) 7 or greater (GS >/=7) prostate cancer. Materials and Methods Two radiologists independently provided PI-RADS V2 scores for the dominant lesion on 343 prostate magnetic resonance (MR) examinations. Diagnostic performance for GS >/=7 tumor was assessed by using MR imaging-ultrasonography fusion-targeted biopsy as the reference. The impact of existing PI-RADS V2 decision rules, as well as a series of exploratory proposed adjustments, on the frequency of GS >/=7 tumor detection, was evaluated. Results A total of 210 lesions were benign, 43 were GS 6, and 90 were GS >/=7. Lesions were GS >/=7 in 0%-4.1% of PI-RADS categories 1 and 2, 11.4%-27.1% of PI-RADS category 3, 44.4%-49.3% of PI-RADS category 4, and 72.1%-73.7% of PI-RADS category 5 lesions. PI-RADS category 4 or greater had sensitivity of 78.9%-87.8% and specificity of 75.5%-79.1 for detecting GS >/=7 tumor. The frequency of GS >/=7 tumor for existing PI-RADS V2 decision rules was 30.0%-33.3% in peripheral zone (PZ) lesions upgraded from category 3 to 4 based on dynamic contrast enhancement (DCE) score of positive; 50.0%-66.7% in transition zone (TZ) lesions upgraded from category 3 to 4 based on diffusion-weighted imaging (DWI) score of 5; and 71.7%-72.7% of lesions in both zones upgraded from category 4 to 5 based on size of 15 mm or greater. The frequency of GS >/=7 tumor for proposed adjustments to the decision rules was 30.0%-60.0% for TZ lesions upgraded from category 3 to 4 based on DWI score of 4; 33.3%-57.1% for TZ lesions upgraded from category 3 to 4 based on DCE score of positive when incorporating new criteria (unencapsulated sheetlike enhancement) for DCE score of positive in TZ; and 56.4%-61.9% for lesions in both zones upgraded from category 4 to 5 based on size of 10-14 mm. Other proposed adjustments yielded GS >/=7 tumor in less than 15% of cases for one or more readers. Conclusion Existing PI-RADS V2 decision rules exhibited reasonable performance in detecting GS >/=7 tumor. Several proposed adjustments to the criteria (in TZ, upgrading category 3 to 4 based on DWI score of 4 or modified DCE score of positive; in PZ or TZ, upgrading category 4 to 5 based on size of 10-14 mm) may also have value for this purpose. (c) RSNA, 2016 Online supplemental material is available for this article.
PMID: 27783538
ISSN: 1527-1315
CID: 2288742
Diagnosis of superior glenoid labraltears using MRI and MRA: A systematic review and meta-analysis [Meeting Abstract]
Purpose: Superior glenoid labral tears remain one of the most common causes of shoulder pain and loss of shoulder function. The clinical presentation for this group of patients can be non-specific. Thus imaging, in particular, MRI plays an important role in diagnosis. Currently, there is no consensus in terms of the most appropriate type of MRI to be used in this setting. The objective of this study was to evaluate the diagnostic accuracy of non-enhanced magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) for diagnosis of superior labral tears in the shoulder. Materials and Methods: We performed a literature search (until August 2016) using PubMed (MEDLINE), Embase, ISIWeb of Science, Scopus, and national/international conference databases. The inclusion criteria consisted of original research studies that assessed the diagnostic accuracy of MRI, direct (d) MRA, and/or indirect (i) MRA for the detection of superior labral (SLAP) tears, while using arthroscopic findings as the reference standard. The methodological quality of each study was assessed with the use of the QUADAS 2 (Quality Assessment of Diagnostic Accuracy Studies) tool. Pooled sensitivities and specificities, and summary receiver-operating characteristic curves were calculated for each imaging strategy. Additional subgroup analyses compared 3 T and 1.5 T examinations of dMRI and MRA studies as well as low bias MRI and MRA studies. Study homogeneity was assessed visually on the basis of observed differences between study characteristics and methodologies, examination of the forest plots, and Cohran's Q tests of heterogeneity. Results: There were a total of 32 studies that met our inclusion criteria, including a total of 3525 total imaging examinations (1970 d-MRA, 1393 MRI, 162 iMRA). The sensitivities of dMRA, MRI, and iMRA for diagnosis of SLAP tear were 80.3% (CI 74.6-85.5), 62.9% (46.1-78.4), and 74.2 (66.1-81.6), respectively. The specificities of dMRA, MRI, and iMRA for diagnosis of SLAP tear were 90.7% (85.3-94.9), 90.8% (84.8-95.4), and 66.4 (51.0-79.6), respectively. The sensitivities of 3 T dMRA and 3 T MRI were 81.7% (71.6-89.9) and 79.4 (70.6-86.6). The specificities of 3 T dMRA and 3 T MRI were 94.3% (89.3-97.7) and 98.8% (95.8-99.8). The sensitivities of 1.5 T dMRA and 1.5 TMRI were 79.1% (68.9-87.7) and 81.2% (62.9-94.3). The specificities of 1.5 T dMRA and 1.5 T MRI were 83.6% (74.6-90.9) and 83.4% (78.9-87.3). The sensitivities of the low bias dMRA and low bias MRI were 83.2% (75.2-89.9) and 61.7 (40.7-80.7). The specificities of the low bias dMRA and low bias MRI were 90.6% (81.9-96.6) and 95.0% (85.1-99.7). No study heterogeneity was noted on the basis of observed differences between study characteristics, but it was noted upon examination of the forest plot for the pooled MRI sensitivities. Significance in departure from study homogeneity (p < .05) was seen for the dMRA and MRI pooled estimates. Conclusion: Overall, direct MR arthrography of the shoulder may be a better imaging option than non-contrast MRI for the diagnosis of a superior labral tear. 3 T MRI and 3 T dMRA may be better imaging options than their 1.5 T counterparts. These findings should be considered in the context of the degree of heterogeneity found in the available literature
EMBASE:614350287
ISSN: 1432-2161
CID: 2454382
Clinical applicability and relevance of fibroglandular tissue segmentation on routine T1 weighted breast MRI
PURPOSE: To evaluate clinical applicability of fibroglandular tissue (FGT) segmentation on routine T1 weighted breast MRI and compare FGT quantification with radiologist assessment. METHODS: FGT was segmented on 232 breasts and quantified, and was assessed qualitatively by four breast imagers. RESULTS: FGT segmentation was successful in all 232 breasts. Agreement between radiologists and quantified FGT was moderate to substantial (kappa=0.52-0.67); lower quantified FGT was associated with disagreement between radiologists and quantified FGT (P
PMID: 27951458
ISSN: 1873-4499
CID: 2363342
Journal of vascular & interventional radiology. 2017:28(Suppl):S7-S8.DOI: 10.1016/j.jvir.2016.12.594
Abstract No. 9 - Assessing the effect of multiple peripherally inserted central catheter insertions in a pediatric population: a single-center retrospective review
CINAHL:121066467
ISSN: 1051-0443
CID: 2463912
Background parenchymal enhancement over exam time in patients with and without breast cancer
PURPOSE: To compare background parenchymal enhancement (BPE) over time in patients with and without breast cancer. MATERIALS AND METHODS: This retrospective Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant study included 116 women (25-84 years, mean 54 years) with breast cancer who underwent breast magnetic resonance imaging at 3T between 1/2/2009 and 12/29/2009 and 116 age and date-of-exam-matched women without breast cancer (23-84 years, mean 51 years). Two independent, blinded readers (R1, R2) recorded BPE (minimal, mild, moderate, marked) at three times (100, 210, and 320 seconds postcontrast). Subsequent cancers were diagnosed in 9/96 control patients with follow up (12.6-93.0 months, mean 63.6 months). Exact Mann-Whitney, Fisher's exact, and McNemar tests were performed. RESULTS: Mean BPE was not found to be different between patients with and without breast cancer at any time (P = 0.36-0.64). At time 2 as compared with time 1, there were significantly more patients, both with and without breast cancer, with BPE >minimal (R1: 90 vs. 41 [P < 0.001] and 81 vs. 36 [P < 0.001]; R2: 84 vs. 52 [P < 0.001] and 79 vs. 43 [P < 0.001]) and BPE >mild (R1: 59 vs. 10 [P < 0.001] and 47 vs. 13 [P < 0.001]; R2: 49 vs. 12 [P < 0.001] and 41 vs. 18 [P < 0.001]). BPE changes between times 2 and 3 were not significant (P = 0.083-1.0). Odds ratios for control patients developing breast cancer were significant only for R2 and ranged up to 7.67 (1.49, 39.5; P < 0.01) for BPE >mild at time 2. CONCLUSION: BPE changes between the first and second postcontrast scans and stabilizes thereafter in most patients. Further investigation into the most clinically relevant timepoint for BPE assessment is warranted. J. Magn. Reson. Imaging 2016.
PMID: 27285396
ISSN: 1522-2586
CID: 2136622
Hepatocellular carcinoma detection: diagnostic performance of a simulated abbreviated MRI protocol combining diffusion-weighted and T1-weighted imaging at the delayed phase post gadoxetic acid
PURPOSE: The purpose of this study was to evaluate the diagnostic performance of a "simulated" abbreviated MRI (AMRI) protocol using diffusion-weighted imaging (DWI) and T1-weighted (T1w) imaging obtained at the hepatobiliary phase (HBP) post gadoxetic acid injection alone and in combination, compared to dynamic contrast-enhanced (CE)-T1w imaging for the detection of hepatocellular carcinoma (HCC). METHODS: This was an IRB approved HIPAA compliant retrospective single institution study including patients with liver disease who underwent gadoxetic acid-enhanced MRI for HCC diagnosis. Three independent observers assessed 2 sets of images (full CE-set and AMRI including DWI+T1w-HBP). Diagnostic performance of T1w-HBP and DWI alone and in combination was compared to that of CE-set. All imaging sets included unenhanced T1w and T2w sequences. A preliminary analysis was performed to assess cost savings of AMRI protocol compared to a full MRI study. RESULTS: 174 patients including 62 with 80 HCCs were assessed. Equivalent per-patient sensitivity and negative predictive value (NPV) were observed for DWI (85.5% and 92.2%, pooled data) and T1w-HBP (89.8% and 94.2%) (P = 0.1-0.7), while these were significantly lower for the full AMRI protocol (DWI+T1w-HBP, 80.6% and 80%, P = 0.02) when compared to CE-set (90.3% and 94.9%). Higher specificity and positive predictive value were observed for CE-set vs. AMRI (P = 0.02). The estimated cost reduction of AMRI versus full MRI ranged between 30.7 and 49.0%. CONCLUSION: AMRI using DWI and T1w-HBP has a clinically acceptable sensitivity and NPV for HCC detection. This could serve as the basis for a future study assessing AMRI for HCC screening and surveillance.
PMID: 27448609
ISSN: 2366-0058
CID: 2191322
