Publications

PURPOSE: To assess patient and provider satisfaction with interventional radiology (IR) outpatient telehealth and in-person clinic.

MATERIALS AND METHODS: This institutional review board-approved study analyzed patient satisfaction with clinic via survey after an IR outpatient telehealth or in-person visit. A physician telehealth experience survey was completed by 8 IR physicians.

RESULTS: During the initial survey period, 44 (83%) of 53 patients completed a survey via telephone compared with 37 (23%) of 158 patients who were offered an electronic survey during the second survey period. Of 81 respondents, 18 (22%) were in-person and 63 (78%) were via telehealth. Of the respondents, nearly all patients (97%) in the telehealth group reported satisfaction with their telehealth clinic visit, with similar rates of high patient satisfaction between in-person and telehealth visits (P = .51). Most patients (98%) in the telehealth group strongly agreed that their physician's recommendations were clear in the telehealth visit and that their visit was private, similar to in-person visits (P = .13). A telehealth visit saved time for all patients (100%), with 78% reporting >1 hour of time-saving. All IR physicians (n = 8) reported greater efficiency with telehealth clinic than with in-person clinic and that follow-up patterns would change if telehealth was available. However, all providers (100%) found telephone visits less satisfying than in-person visits, with video visits being either equally satisfying (71%) or less satisfying (29%).

CONCLUSIONS: Patient satisfaction with the in-person and telehealth outpatient IR clinic was high, with patients and providers reporting time-saving and greater efficiency with telehealth, suggesting that telehealth should remain an important component of outpatient IR clinic care.

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver worldwide. Noninvasive diagnosis of HCC is possible based on imaging features, without the need for tissue diagnosis. Liver Imaging Reporting and Data System (LI-RADS) CT/MRI diagnostic algorithm allows for standardized radiological interpretation and reporting of imaging studies for patients at high risk for HCC. Diagnostic categories of LR-1 to LR-5 designate each liver observation to reflect the probability of overall malignancy, HCC, or benignity based on imaging features, where LR-5 category has > 95% probability of HCC. Optimal imaging protocol and scanning technique as described by the technical recommendations for LI-RADS are essential for the depiction of features to accurately characterize liver observations. The LI-RADS MRI technical guidelines recommend the minimum required sequences of T1-weighted out-of-phase and in-phase Imaging, T2-weighted Imaging, and multiphase T1-weighted Imaging. Additional sequences, including diffusion-weighted imaging, subtraction imaging, and the hepatobiliary phase when using gadobenate dimeglumine as contrast, improve diagnostic confidence, but are not required by the guidelines. These optional sequences can help differentiate true lesions from pseudolesions, detect additional observations, identify parenchymal observations when other sequences are suboptimal, and improve observations conspicuity. This manuscript reviews the optional sequences, the advantages they offer, and discusses technical optimization of these sequences to obtain the highest image quality and to avoid common artifacts.

PURPOSE: To evaluate the benefits of fast spin echo (FSE) imaging over rapid gradient-echo (RAGE) for magnetization-prepared inhomogeneous magnetization transfer (ihMT) imaging.

METHODS: A 3D FSE sequence was modified to include an ihMT preparation (ihMT-FSE) with an optional CSF suppression based on an inversion-recovery (ihMT-FLAIR). After numeric simulations assessing SNR benefits of FSE and the potential impact of an additional inversion-recovery, ihMT-RAGE, ihMT-FSE, and ihMT-FLAIR sequences were compared in a group of six healthy volunteers, evaluating image quality, thermal, and physiological noise as well as quantification using an ihMT saturation (ihMTsat) approach. A preliminary exploration in the cervical spinal cord was also conducted in a group of three healthy volunteers.

RESULTS: Several fold improvements in thermal SNR were observed with ihMT-FSE in agreement with numerical simulations. However, we observed significantly higher physiological noise in ihMT-FSE compared to ihMT-RAGE that was mitigated in ihMT-FLAIR, which provided the best total SNR (+74% and +49% compared to ihMT-RAGE in the white and gray matter, P ≤ 0.004). IhMTsat quantification was successful in all cases with strong correlation between all sequences (r2  > 0.75). Early experiments showed potential for spinal cord imaging.

CONCLUSIONS: FSE generally offers higher SNR compared to gradient-echo based acquisitions for magnetization-prepared contrasts as illustrated here in the case of ihMT. However, physiological noise has a significant effect, but an inversion-recovery-based CSF suppression was shown to be efficient in mitigating effects of CSF motion.

PURPOSE: Surgical resection is the only potential curative treatment for patients with pancreatic ductal adenocarcinoma (PDAC), but unfortunately most patients recur within 5 years of surgery. This article aims to assess the practice patterns across major academic institutions and develop consensus recommendations for postoperative imaging and interpretation in patients with PDAC.

METHODS: The consensus recommendations for postoperative imaging surveillance following PDAC resection were developed using the Delphi method. Members of the Society of Abdominal Radiology (SAR) PDAC Disease Focused Panel (DFP) underwent three rounds of surveys followed by live webinar group discussions to develop consensus recommendations.

RESULTS: Significant variations currently exist in the postoperative surveillance of PDAC, even among academic institutions. Differentiating common postoperative inflammatory and fibrotic changes from tumor recurrence remains a diagnostic challenge, and there is no reliable size threshold or growth rate of imaging findings that can provide differentiation. A new liver lesion or peritoneal nodule should be considered suspicious for tumor recurrence, and the imaging features should be interpreted in the appropriate clinical context (e.g., CA 19-9, clinical presentation, pathologic staging).

CONCLUSION: Postoperative imaging following PDAC resection is challenging to interpret due to the presence of confounding postoperative inflammatory changes. A standardized reporting template for locoregional findings and report impression may improve communication of relaying risk of recurrence with referring providers, which merits validation in future studies.

OBJECTIVE: To examine the comparative effectiveness of magnetic resonance imaging-ultrasound (MRI-U/S) fusion biopsy and in-bore MRI-targeted biopsy.

METHODS: We identified men aged 18-89 with a diagnosis of elevated prostate specific antigen (PSA) or Gleason 6 prostate cancer on active surveillance who underwent MRI-U/S fusion prostate biopsy (12-core + targeted) in the office or in-bore MRI-targeted biopsy (MRI-IB; targeted only). The cancer detection rate (CDR; Gleason 6-10) and clinically significant CDR (csCDR; Gleason 7-10) were compared across biopsy techniques, adjusted for patient and radiographic features.

RESULTS: A total of 280 patients (346 lesions) were included, of whom 23.9% were on active surveillance for Gleason 6 prostate cancer. In the per-patient analyses, there was no statistically significant difference in adjusted overall CDR (64.1% vs 54.2%; P = .24) or csCDR (36.5% vs 37.9%; P = .85) between MRI-U/S and MRI-IB biopsy. In the per-lesion analyses, there was no statistically significant difference in adjusted overall CDR (45.7% vs 50.1%; P = .49) between MRI-U/S and MRI-IB biopsy, but MRI-IB biopsy was associated with a higher csCDR than MRI-U/S biopsy (32.8% vs 21.4%; P = .02).

CONCLUSION: We observed no statistically significant differences in cancer detection rates between MRI-U/S fusion biopsy and MRI-IB biopsy in per-patient analyses. However, MRI-IB biopsy was associated with higher csCDR when considering targeted biopsy cores only. These results suggest that systematic cores should be obtained when performing MRI-U/S fusion biopsy.

BACKGROUND. CT guidance may be used for biopsy of indeterminate bone lesions detected by MRI or PET/CT that are not visible (i.e., occult) on CT owing to equipment-, patient-, and operator-related factors. OBJECTIVE. The purpose of this study was to assess diagnostic yield (DY) and diagnostic performance of CT-guided core needle biopsy (CNB) of occult nonspinal bone lesions and to identify the most common benign and malignant diagnoses for occult lesions undergoing CNB. METHODS. This retrospective study included 1033 adult patients who underwent CT-guided nonspinal bone CNB between January 2004 and December 2020. Lesions were classified as occult or visible on CT; biopsies of occult lesions were performed by targeting anatomic landmarks using prebiopsy MRI or PET/CT. Pathologic results of CNB were classified as diagnostic or nondiagnostic to calculate DY of CNB. For nondiagnostic CNBs, final diagnoses were established by subsequent pathologic, clinical, and imaging follow-up. RESULTS. The sample included 70 patients with occult lesions (mean age, 56.8 years; 38 women, 32 men) and 963 patients with visible lesions (mean age, 59.6 years; 475 women, 488 men). Malignancy rate was lower for occult than for visible lesions (42.9% vs 60.9%, p = .004). DY was lower for occult than for visible lesions (37.1% vs 76.9%, p < .001). Diagnostic performance for detecting malignancy on the basis of final diagnoses was lower for occult than for visible lesions in terms of sensitivity (76.7% vs 93.7%, p = .003), specificity (7.9% vs 56.5%, p < .001), and accuracy (38.2% vs 80.0%, p < .001). Final diagnoses among malignant occult and visible lesions included metastasis (frequencies of 63.3% vs 65.4%), leukemia/lymphoma (33.3% vs 11.6%), and myeloma (3.3% vs 10.4%); final diagnoses among benign occult and visible lesions included red marrow (34.2% vs 8.2%), reactive marrow (26.3% vs 11.8%), and fracture (18.4% vs 3.8%). Occult lesions detected by MRI versus PET/CT had lower malignancy rate (39.3% vs 68.0%, p = .03) and lower DY (30.4% vs 60.0%, p = .01). CONCLUSION. At CT-guided CNB, malignancy rate and DY are lower for occult than for visible lesions. Leukemia/lymphoma and red marrow are more common among occult than visible lesions. CLINICAL IMPACT. Understanding these characteristics can help guide radiologists', referring providers', and patients' expectations when CNB of occult bone lesions is requested and performed.

Lymphedema is a devastating disease that has no cure. Management of lymphedema has evolved rapidly over the past two decades with the advent of surgeries that can ameliorate symptoms. MRI has played an increasingly important role in the diagnosis and evaluation of lymphedema, as it provides high spatial resolution of the distribution and severity of soft tissue edema, characterizes diseased lymphatic channels, and assesses secondary effects such as fat hypertrophy. Many different MR techniques have been developed for the evaluation of lymphedema, and the modality can be tailored to suit the needs of a lymphatic clinic. In this review article we provide an overview of lymphedema, current management options, and the current role of MRI in lymphedema diagnosis and management. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 5.

BACKGROUND AND PURPOSE: Cerebral microbleed (CMB) detection impacts disease diagnosis and management. Susceptibility-weighted imaging (SWI) MRI depictions of CMBs are used with phase images (SWIP) to distinguish blood from calcification, via qualitative intensity evaluation (bright/dark). However, the intensities depicted for a single lesion can vary within and across consecutive SWIP image planes, impairing the classification of findings as a CMB. We hypothesize that quantitative susceptibility mapping (QSM) MRI, which maps tissue susceptibility, demonstrates less in- and through-plane intensity variation, improving the clinician's ability to categorize a finding as a CMB.

METHODS: Forty-eight patients with acute intracranial hemorrhage who received multi-echo gradient echo MRI used to generate both SWI/SWIP and morphology-enabled dipole inversion QSM images were enrolled. Five hundred and sixty lesions were visually classified as having homogeneous or heterogeneous in-plane and through-plane intensity by a neuroradiologist and two diagnostic radiology residents using published rating criteria. When available, brain CT scans were analyzed for calcification or acute hemorrhage. Relative risk (RR) ratios and confidence intervals (CIs) were calculated using a generalized linear model with log link and binary error.

RESULTS: QSM showed unambiguous lesion signal intensity three times more frequently than SWIP (RR = 0.3235, 95% CI 0.2386-0.4386, p<.0001). The probability of QSM depicting homogeneous lesion intensity was three times greater than SWIP for small (RR = 0.3172, 95% CI 0.2382-0.4225, p<.0001), large (RR = 0.3431, 95% CI 0.2045-0.5758, p<.0001), lobar (RR = 0.3215, 95% CI 0.2151-0.4805, p<.0001), cerebellar (RR = 0.3215, 95% CI 0.2151-0.4805, p<.0001), brainstem (RR = 0.3100, 95% CI 0.1192-0.8061, p = .0163), and basal ganglia (RR = 0.3380, 95% CI 0.1980-0.5769, p<.0001) lesions.

CONCLUSIONS: QSM more consistently demonstrates interpretable lesion intensity compared to SWIP as used for distinguishing CMBs from calcification.