Automating Perforator Flap MRA and CTA Reporting.

Surgical breast reconstruction after mastectomy requires precise perforator coordinates/dimensions, perforator course, and fat volume in a radiology report. Automatic perforator reporting software was implemented as an OsiriX Digital Imaging and Communications in Medicine (DICOM) viewer plugin. For perforator analysis, the user identifies a reference point (e.g., umbilicus) and marks each perforating artery/vein bundle with multiple region of interest (ROI) points along its course beginning at the muscle-fat interface. Computations using these points and analysis of image data produce content for the report. Post-processing times were compared against conventional/manual methods using de-identified images of 26 patients with surgically confirmed accuracy of perforator locations and caliber. The time from loading source images to completion of report was measured. Significance of differences in mean processing times for this automated approach versus the conventional/manual approach was assessed using a paired t test. The mean conventional reporting time for our radiologists was 76 ± 27 min (median 65 min) compared with 25 ± 6 min (median 25 min) using our OsiriX plugin (p < 0.01). The conventional approach had three reports with transcription errors compared to none with the OsiriX plugin. Otherwise, the reports were similar. In conclusion, automated reporting of perforator magnetic resonance angiography (MRA) studies is faster compared with the standard, manual approach, and transcription errors which are eliminated.

Electrocardiographic Pad for Efficient Cardiac MR Gating.

PURPOSE: To assess feasibility and reliability of electrocardiographic (ECG)-gated cardiac magnetic resonance (MR) imaging with a simplified reusable electrode design that does not touch the skin. MATERIALS AND METHODS: In this institutional review board-approved, HIPAA-compliant study, a silicon positioner held four ECG leads and detected ECG signals without requiring shaving, adhesive, or removal of the gown. The patient lies down on the device and the patient's weight ensures good lead contact against patient's gown; electrode gel that soaks through the gown provides electrical contact with the skin. It was tested at 1.5 T on 12 volunteers and 52 patients by using double inversion recovery, steady-state, fast gradient-echo time course perfusion, and delayed inversion recovery sequences. Paired Student t test was used to assess the significance of differences in durations to apply and remove ECG pad and standard leads. Image quality was assessed and rated on a four-point scale by two readers. The ECG signal quality obtained from pad and leads was rated on a five-point scale. Ventricular septal sharpness and signal-to-noise ratio were measured on images generated by ECG gating from pads and standard leads. RESULTS: Application and removal duration was 444 seconds with standard leads compared with 296 seconds with the ECG pad, and mean difference in setup time was 148 seconds (P = .005). Ventricular septal sharpness (1/slope) was 165 for ECG pad and 152 for standard leads (P = .3). Septal signal-to-noise ratio on images generated by cardiac gating with ECG pad was 38 ± 12 (standard deviation) compared with 39 ± 14 for standard leads (P = .7). The qualitative image quality score for ECG pad (3.9 ± 0.19) was comparable to ECG leads (3.8 ± 0.45; P = .47). The mean ECG signal qualitative scores were also comparable (pad vs leads, 4.9 ± 0.43 vs 4.9 ± 0.14, respectively; P = .9). Volunteers preferred the ECG pad and reported that it was comfortable and convenient. ECG pad was successful in 50 of 52 (96%) patients. Two patients, including one with large pleural effusions and another with ventricular tachycardia, were not successfully gated. CONCLUSION: This simplified approach to ECG gating is faster to set up and more convenient and comfortable for patients.

Pancreatic Cysts in Autosomal Dominant Polycystic Kidney Disease: Prevalence and Association with PKD2 Gene Mutations.

Purpose To define the magnetic resonance (MR) imaging prevalence of pancreatic cysts in a cohort of patients with autosomal dominant polycystic kidney disease (ADPKD) compared with a control group without ADPKD that was matched for age, sex, and renal function. Materials and Methods In this HIPAA-compliant, institutional review board-approved study, all patients with ADPKD provided informed consent; for control subjects, informed consent was waived. Patients with ADPKD (n = 110) with mutations identified in PKD1 or PKD2 and control subjects without ADPKD or known pancreatic disease (n = 110) who were matched for age, sex, estimated glomerular filtration rate, and date of MR imaging examination were evaluated for pancreatic cysts by using axial and coronal single-shot fast spin-echo T2-weighted images obtained at 1.5 T. Total kidney volume and liver volume were measured. Univariate and multivariable logistic regression analyses were conducted to evaluate potential associations between collected variables and presence of pancreatic cysts among patients with ADPKD. The number, size, location, and imaging characteristics of the cysts were recorded. Results Patients with ADPKD were significantly more likely than control subjects to have at least one pancreatic cyst (40 of 110 patients [36%] vs 25 of 110 control subjects [23%]; P = .027). In a univariate analysis, pancreatic cysts were more prevalent in patients with ADPKD with mutations in PKD2 than in PKD1 (21 of 34 patients [62%] vs 19 of 76 patients [25%]; P = .0002). In a multivariable logistic regression model, PKD2 mutation locus was significantly associated with the presence of pancreatic cysts (P = .0004) and with liver volume (P = .038). Patients with ADPKD and a pancreatic cyst were 5.9 times more likely to have a PKD2 mutation than a PKD1 mutation after adjusting for age, race, sex, estimated glomerular filtration rate, liver volume, and total kidney volume. Conclusion Pancreatic cysts were more prevalent in patients with ADPKD with PKD2 mutation than in control subjects or patients with PKD1 mutation. (©) RSNA, 2016 Online supplemental material is available for this article.

Morphine three-dimensional T1 gadoxetate MR cholangiography of potential living related liver donors.

PURPOSE: To assess low-dose morphine for distension and improved visualization of intrahepatic bile ducts on T1 MR cholangiography (MRC) in preoperative imaging of potential liver donors. MATERIALS AND METHODS: Sixty-nine consecutive potential living related liver donors (mean age, 39 years; age range, 20 to 59 years) referred for pre-transplant MRI evaluation were evaluated without (n=30) or with (n=39) intravenous morphine injection (0.04 mg/kg). Morphine was injected pre-MRI while establishing intravenous access to allow ∼1 h for biliary distension before T1 MRC. Three radiologists reviewed intrahepatic biliary branch order visualization, common bile duct (CBD) diameter, and overall image quality. In 25 patients undergoing liver donation surgery, T1 MRC findings were correlated with intraoperative findings. This retrospective study was approved by the institutional review board. RESULTS: Biliary visualization was improved post-morphine administration with biliary duct branch order visualization score of 3.2 and 3.3 at 45 and 60 min, respectively, compared with 2.7 without morphine (P<0.002); CBD diameter measured 5.3 and 5.5 versus 4.1 mm (P<0.005), and overall image quality score was 2.4 and 2.6 versus 1.8 (P<0.0006). Operative notes confirmed T1 MRC findings in 6/11 donors without morphine and 14/14 donors with morphine. CONCLUSION: Intravenous low-dose morphine distends and improves visualization of bile ducts on T1 gadoxetate MRC.

Patient-Centered Radiology Communications: Engaging Patients as Partners.

Patient-centered care is a model in which, by bringing the patient's perspective to the design and delivery of health care, we can better meet patients' needs, enhancing the quality of care. Patient-centered care requires finding ways to communicate effectively with a diverse patient population that has various levels of health literacy, cultural backgrounds, and unique needs and preferences. Moreover, multimedia resources have the potential to inform and educate patients promoting greater independence. In this review, we discuss the fundamentals of communication with the different modes used in radiology and the key elements of effective communication. Then, we highlight five opportunities along the continuum of care in the radiology practice in which we can improve communications to empower our patients and families and strengthen this partnership. Lastly, we discuss the importance on communication training of the workforce, optimizing and seamlessly integrating technology solutions into our workflows, and the need for patient feedback in the design and delivery of care.

Improved hepatic arterial phase MRI with 3-second temporal resolution.

PURPOSE: To assess 3-s temporal resolution for arterial phase bolus timing on dynamic liver MRI. MATERIALS AND METHODS: One hundred consecutive patients undergoing fluoro-triggered dynamic gadoxetate enhanced liver MRI with standard Cartesian k-space LAVA (Liver Acquisition with Volume Acceleration) were compared with 61 consecutive patients imaged using spiral k-space LAVA reconstructed at 3-s temporal resolution with sliding window reconstruction. For qualitative analysis, bolus timing, hepatic artery branch order visualized, and overall image quality were evaluated. For quantitative analysis, contrast to noise ratio between aorta and liver parenchyma, aorta and portal vein, and signal intensity ratio between aorta and liver parenchyma were calculated. RESULTS: MR fluoroscopy triggered single phase standard LAVA produced optimal arterial phase timing in 35% patients, compared with 88% with Spiral LAVA (P < 0.0001). Spiral LAVA had superior bolus timing scoring 2.0, compared with 1.0 with standard LAVA (P < 0.0001). Overall image quality and hepatic artery branch order visualization scoring were superior on spiral LAVA, compared with standard LAVA (P < 0.001). The aorta to liver parenchyma signal intensity ratio was also superior on spiral LAVA, compared with standard LAVA (2.8 vs. 2.2; P < 0.001). CONCLUSION: Dynamic liver MRI bolus timing improves using 3-s temporal resolution.

Evaluation of the LI-RADS treatment response algorithm in hepatocellular carcinoma after trans-arterial chemoembolization.

PURPOSE: To evaluate the diagnostic performance of LI-RADS treatment response algorithm (LR-TRA) and modified RECIST (mRECIST) for the detection of viable hepatocellular carcinoma (HCC) on MRI after trans-arterial chemoembolization (TACE). MATERIALS AND METHODS: This retrospective study includes cirrhotic patients that underwent trans-arterial chemoembolization prior to liver transplantation from 2013 to 2017 with a pre- and post-treatment MRI available. Three blinded readers assigned a LR-TRA and mRECIST category to each lesion. Lesions on MRI and explant pathology were matched and characterized as complete (100% necrosis) or incomplete necrosis (≤99% necrosis). Diagnostic performance of LR-TRA and mRECIST were calculated with a generalized estimating equation. RESULTS: A total of 52 patients with 71 lesions were included, 47 with incomplete and 24 with complete necrosis. In consensus, 45 lesions were categorized as LR-TR Nonviable, of which 62.2% (28/45) had incomplete and 37.8% (17/45) had complete necrosis. Six lesions were categorized as LR-TR Equivocal, of which 33.3% (2/6) had incomplete and 66.7% (4/6) had complete necrosis. Twenty lesions were categorized as LR-TR Viable of which 85.0% (17/20) had incomplete and 15.0% (3/20) had complete necrosis. The sensitivity of LR-TR Viable for detecting incompletely necrotic tumor when LR-TR Equivocal was considered as viable, in consensus was 40.4%; specificity 70.8%; accuracy 50.7%. The sensitivity of mRECIST for detecting incompletely necrotic tumor was 37.0%; specificity 79.2%; accuracy 51.4%. There was no significant difference in diagnostic performance between mRECIST and LR-TRA (p = 0.14-0.33). Agreement for LR-TRA category was moderate (k = 0.53 [95% CI: 0.45, 0.67]). CONCLUSION: LI-RADS treatment response algorithm demonstrates high specificity and low to moderate sensitivity for the detection of viable HCC after TACE in a North American cirrhotic cohort, without significant difference in diagnostic performance between LR-TRA and mRECIST.

PI-RADS: what is new and how to use it.

The prostate imaging reporting and data system (PI-RADS) has revolutionized the use of magnetic resonance imaging (MRI) for the management of prostate cancer (PCa). The most recent version 2.1, PI-RADS v2.1, provides specific refinements in the performance, relaxing some recommendations which were not found to be helpful, while reinforcing and clarifying others. The interpretation of T2-weighted imaging (T2WI) in the transition zone (TZ), and the overall assessment of TZ nodules, now allows for a clearer distinction between those which are clearly benign and those which might warrant tissue sampling. Additional changes also resolve discrepancies in T2WI and diffusion-weighted imaging (DWI) of the peripheral zone (PZ). PI-RADS v2.1 is a simpler, more straightforward, and more reproducible method to better communicate between physicians regarding findings on prostate MRI.

Molecular imaging and therapy of somatostatin receptor positive tumors.

Somatostatin receptors (SSTR) are upregulated in the cells of origin that define numerous neuroendocrine neoplasms. PET imaging with 68Ga-DOTATATE allows specific targeting of SSTR2A, a single species of SSTR receptor, which is commonly overexpressed in a variety of gastroenteropancreatic neuroendocrine tumors, as well as pulmonary carcinoid and head and neck tumors. Due to more specific targeting of SSTR2 as well as lower radiation dose, shorter study length, ability to quantify uptake, and lower cost, 68Ga-DOTATATE has demonstrated superior imaging attributes when compared to 111In-pentetreotide. As with any novel imaging modality, dedicated training, increasing experience and staying up-to-date with scientific publications are required to provide optimal patient care. The purpose of this review is to summarize the current state of the art in SSTR-targeted molecular imaging and discuss ongoing and future potential diagnostic and therapeutic applications.

Imaging of Bone Perfusion and Metabolism in Subjects Undergoing Total Ankle Arthroplasty Using 18F-Fluoride Positron Emission Tomography.

BACKGROUND: Total ankle arthroplasty (TAA) continues to exhibit a relatively high incidence of complications and need for revision surgery compared to knee and hip arthroplasty. One common mode of failure in TAA is talar component subsidence. This may be caused by disruption in the talar blood supply related to the operative technique. The purpose of this study was to quantify changes in talar bone perfusion and turnover before and after TAA with the INBONE II system using 18F-fluoride positron emission tomography / computed tomography (PET/CT). METHODS: Nine subjects (5 M/4 F) aged 68.9 ± 8.2 years were enrolled for 18F-fluoride PET/CT imaging before and 3 months after TAA. Regions of interest (ROI) were placed on the postoperative CT images in the body of the talus beneath the talar component and overlaid on the fused static PET images. Standard uptake values (SUVs) along with dynamic K1 (bone blood flow) and ki (bone metabolism or osteoblastic turnover) were calculated. RESULTS: The SUV underneath the talar component compared to that measured at baseline before surgery was 1.93 ± 0.29 preoperatively vs 2.47 ± 0.37 postoperatively (P > .05). K1 was 0.84 ± 0.16 mL/min/mL preoperatively vs 1.51 ± 0.23 mL/min/mL postoperatively (P = .026). ki was constant at 0.09 ± 0.03 mL/min/mL preoperatively vs 0.12 ± 0.03 mL/min/mL postoperatively (P > .05). CONCLUSION: Our study was the first to link 18F-fluoride PET/CT with pre-post evaluation of total ankle replacements. The study quantified perfusion within the talus beneath the TAA implant supporting the hypothesis that perfusion of the talus remained intact after surgery. LEVEL OF EVIDENCE: Level II, prospective cohort study with development of diagnostic criteria.

Quantitative evaluation of gadoxetate hepatocyte phase homogeneity: potential imaging markers for detection of early cirrhosis.

OBJECTIVE: Does quantitative analysis of the gadoxetate hepatocyte phase homogeneity, measuring percent standard deviation of hepatocyte phase (SDHP) and liver-to-kidney enhancement ratio (LiKER) detect early hepatic fibrosis? MATERIALS AND METHODS: Retrospective review of gadoxetate liver MRI plus biopsy-proven fibrosis within 6 months included 31 reversible hepatic fibrosis, 33 irreversible hepatic fibrosis, and 15 donors. Parenchymal and vascular SDHP and LiKER were measured on the 20-min hepatocyte phase using region of interest. RESULTS: Parenchymal SDHP, vascular SDHP and LiKER measurements differentiate early hepatic fibrosis from controls (P<.01). CONCLUSION: Quantitative analysis of gadoxetate hepatocyte phase homogeneity using SDHP and LiKER is a promising imaging biomarker for diagnosis of early liver fibrosis.

Breast Tissue Expanders with Magnetic Ports: Clinical Experience at 1.5 T.

BACKGROUND: The purpose of this study was to evaluate breast tissue expanders with magnetic ports for safety in patients undergoing abdominal/pelvic magnetic resonance angiography before autologous breast reconstruction. METHODS: Magnetic resonance angiography of the abdomen and pelvis at 1.5 T was performed in 71 patients in prone position with tissue expanders with magnetic ports labeled "MR Unsafe" from July of 2012 to May of 2014. Patients were monitored during magnetic resonance angiography for tissue expander-related symptoms, and the chest wall tissue adjacent to the tissue expander was examined for injury at the time of tissue expander removal for breast reconstruction. Retrospective review of these patients' clinical records was performed. T2-weighted fast spin echo, steady-state free precession and gadolinium-enhanced spoiled gradient echo sequences were assessed for image artifacts. RESULTS: No patient had tissue expander or magnetic port migration during the magnetic resonance examination and none reported pain during scanning. On tissue expander removal (71 patients, 112 implants), the surgeons reported no evidence of tissue damage, and there were no operative complications at those sites of breast reconstruction. CONCLUSION: Magnetic resonance angiography of the abdomen and pelvis in patients with certain breast tissue expanders containing magnetic ports can be performed safely at 1.5 T for pre-autologous flap breast reconstruction perforator vessel mapping. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Tumor germinal no seminomatoso del mediastino con invasión pulmonar / Mediastinal non seminomatous germ cell tumor with pulmonary compromise

Los tumores germinales extragonadales representan entre el 1 y 2.5% de los tumores de células germinales (TCG), siendo el mediastino la segunda localización en frecuencia luego de las gónadas. Se presenta el caso de un paciente masculino de 29 años de edad que consulta por tos irritativa de cinco meses de evolución. Se realizaron radiografía, tomografía computada (TC) y resonancia magnética (RM) de tórax y ecografía testicular. Los hallazgos por imágenes, sumados a la presencia de marcadores tumorales elevados (alfa-fetoproteína y gonadotrofina coriónica humana), confirmaron el diagnóstico de TCG extragonadal, avalado posteriormente por la cirugía y la anatomía patológica.

The prevalence of extragonadal germ cell tumors is only 1- 2.5% of all germ cell tumors. The mediastinum is the second most common site affected. We present the case of a 29 years old male pacient, with a persistent cough dating back to five months. We performed chest X-R, thorax CT and MRI and testicular US. The findings of this images besides the presence of elevated levels of alpha-fetoprotein and beta-human gonadotropin confirm the diagnosis of extragonadal germ cell tumor.