Preoperative breast MR imaging in newly diagnosed breast cancer: Comparison of outcomes based on mammographic modality, breast density and breast parenchymal enhancement.

PURPOSE: To compare the role of MR for assessment of extent of disease in women newly diagnosed with breast cancer imaged with digital mammography (DM) alone versus digital breast tomosynthesis (DBT). METHODS: Retrospective review was conducted of 401 consecutive breast MR exams (10/1/2013-7/31/2015) from women who underwent preoperative MR for newly diagnosed breast cancer by either DM or DBT, leaving 388 exams (201 DM and 187 DBT). MR detection of additional, otherwise occult, disease was stratified by modality, breast density, and background parenchymal enhancement. A true-positive finding was defined as malignancy in the ipsilateral-breast >2 cm away from the index-lesion or in the contralateral breast. RESULTS: 50 additional malignancies were detected in 388 exams (12.9%), 37 ipsilateral and 13 contralateral. There was no difference in the MR detection of additional disease in women imaged by either DM versus DBT (p = 0.53). In patients with DM, there was no significant difference in the rate of MR additional cancer detection in dense versus non-dense breasts (p = 0.790). However, in patients with DBT, MR detected significantly more additional sites of malignancy in dense compared to non-dense breasts (p = 0.017). There was no difference in false-positive MR exams (p = 0.470) for DM versus DBT. For both DM and DBT cohorts, higher MR background parenchymal enhancement was associated with higher false-positive (p = 0.040) but no significant difference in true-positive exams. CONCLUSIONS: Among patients with DBT imaging at cancer diagnosis, women with dense breasts appear to benefit more from preoperative MR than non-dense women. In women imaged only with DM, MR finds additional malignancy across all breast densities.

Rare Cancer on the Rise: An Educational Review of Breast Implant-associated Anaplastic Large Cell Lymphoma.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare but increasingly important diagnosis as the incidence of breast implant placement, both elective and reconstructive, continues to rise. When detected and treated early, this indolent disease carries an excellent prognosis. However, because the clinical presentation is often nonspecific, it is crucial for radiologists to accurately identify the imaging findings associated with BIA-ALCL to facilitate a timely diagnosis. This article will provide radiologists with an overview of the diagnosis, imaging findings, and management of BIA-ALCL.

Cell-Proliferation Imaging for Monitoring Response to CDK4/6 Inhibition Combined with Endocrine-Therapy in Breast Cancer: Comparison of [18F]FLT and [18F]ISO-1 PET/CT.

PURPOSE: Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in combination with endocrine-therapy have emerged as an important regimen of care for estrogen receptor (ER)-positive metastatic breast cancer, although identifying predictive biomarkers remains a challenge. We assessed the ability of two PET-proliferation tracers, [18F]FLT and [18F]ISO-1, for evaluating response to CDK4/6-inhibitor (palbociclib) and ER-antagonist (fulvestrant). EXPERIMENTAL DESIGN: To determine the effect of CDK4/6 inhibition combined with estrogen-blockade, we assessed cell proliferation in six breast cancer cell lines after 1, 3, and 6 days of treatment with palbociclib and/or fulvestrant. These data were correlated to in vitro radiotracer assays and results were verified by longitudinal [18F]FLT and [18F]ISO-1 micro-PET imaging performed in MCF7 tumor-bearing mice. RESULTS: All palbociclib-sensitive cell lines showed decreased [18F]FLT accumulation and S-phase depletion after treatment, with both measures augmented by combination therapy. In contrast, these cells showed changes in [18F]ISO-1 analogue-binding and G0 arrest only after prolonged treatment. MicroPET imaging of MCF7 xenografts showed a significant decrease in [18F]FLT but no changes in [18F]ISO-1 uptake in all treated mice on day 3. On day 14, however, mice treated with combination therapy showed a significant decrease in [18F]ISO-1, corresponding to G0 arrest, while maintaining reduced [18F]FLT uptake, which corresponded to S-phase depletion. CONCLUSIONS: Our data suggest complementary roles of [18F]FLT and [18F]ISO-1 PET in evaluating tumor-proliferation after combined CDK4/6 inhibitor and endocrine therapy in breast cancer. [18F]FLT is more sensitive to immediate changes in S-phase, whereas [18F]ISO-1 can assess more delayed changes related to cell-cycle arrest and transition to G0 quiescence from combination therapy. These data suggest a potential role for early prediction of long-term response using these imaging biomarkers.

Imaging Tumor Proliferation in Breast Cancer: Current Update on Predictive Imaging Biomarkers.

Uncontrolled growth is a hallmark of cancer; imaging cell proliferation can provides an early indicator of therapeutic response. This capability is especially well-matched to the emerging cell cycle-specific chemotherapeutics with the goal of identifying patients that benefit from these treatments early in the course of treatment to guide personalized therapy. This article focuses on investigational cell proliferation imaging PET radiotracers to evaluate tumor proliferation in the setting of cell cycle-targeted chemotherapy and endocrine therapy for metastatic breast cancer.

Post-Whipple imaging in patients with pancreatic ductal adenocarcinoma: association with overall survival: a multivariate analysis.

PURPOSE: To compare the survival outcomes in patients with pancreatic ductal adenocarcinoma (PDAC) who had regular imaging surveillance with those who had clinical follow-up after Whipple. METHOD: We identified 229 patients, who underwent Whipple for resection of PDAC from 2005 to 2011, and had regular postoperative clinical follow-up at our hospital. Patients were retrospectively selected for two follow-up groups: imaging surveillance (IS) defined as routine imaging at scheduled intervals, vs. clinical (C) defined as imaging triggered by either change in clinical status or change in CA19-9. Follow-up was obtained through the hospital and Cancer Data Registry records. Survival was calculated from the date of surgery to death or last follow-up, with data censored as of March 13, 2013. Kaplan-Meier survival curves were compared using the log-rank test, and Cox regression models were used for multivariate analysis. RESULTS: Patients were followed for a mean period of 24.35 ± 2.56 months. IS-group underwent significantly more imaging (4.41 vs. 2.08 scans/year). The most frequent imaging was CT of chest and abdomen at 3-4 month interval. Univariate associations with overall survival were detected with post-Whipple ECOG status, T-stage, N-stage, tumor grade, surgical margin, recurrence, and IS. In multivariate analysis, grade, ECOG status, and recurrence were independent predictors of survival. Also, our predictor of interest, IS, was highly associated with longer survival in multivariate modeling (median overall survival, 30.4±3.85 (IS-group) vs. 17.1 ± 2.42 (C-groups) month, log-rank p = 0.002). CONCLUSION: Routine imaging surveillance was associated with prolonged overall survival post-Whipple in a multivariate model. This is a hypothesis-generating finding that should be studied prospectively and could ultimately impact surveillance guidelines.

Low-dose Human Chorionic Gonadotropin Stimulation Test as a Prognostic Incontinent Indicator in Boys With Bladder Exstrophy-epispadias Complex.

OBJECTIVE: To investigate the effect of low-dose human chorionic gonadotropin (HCG) administration on structural changes in the lower urinary tract in boys with urinary incontinence in the setting of bladder exstrophy-epispadias complex (BEEC). PATIENTS AND METHODS: We prospectively evaluated 30 patients (median age 7.5 years) with BEEC and randomly divided them into 2 groups. Patients in the HCG group were administered 250 IU HCG intramuscularly 3 times per week during a 4-week period. The other 15 patients served as the control group. The patients were followed up for a mean duration of 4 years. Incontinence rate, hormonal changes, penile length, prostate size, and bladder capacity were evaluated using 3D sonography or pelvic magnetic resonance imaging and uroflowmetry studies before and after HCG administration. RESULTS: The incontinence score improvement was significantly higher in the HCG group (P = .01). A significant increase was detected in the health-related quality of life score of both patients and parents at the final follow-up (P < .001). The total prostate size (P < .0001) and bladder capacity (P < .0001) increased significantly in all patients of the HCG group. Basal serum testosterone level increased significantly after the first (P = .001) and last (P < .001) injections with no significant increase 3 months after the last injection (P > .05). No major side effect was found following the administration of HCG, with no need for open surgical bladder neck reconstruction. CONCLUSION: Our preliminary results suggest the role of low-dose HCG in boys with BEEC suffering from urinary incontinence. The data also reveal the role of prostate enlargement in the improvement of urinary incontinence. Chronic treatment with HCG increases bladder capacity that may facilitate future reconstructive surgery.

Prediction of 5-year survival in advanced-stage ovarian cancer patients based on computed tomography peritoneal carcinomatosis index.

OBJECTIVE: To evaluate whether the quantification of peritoneal metastases in advanced-stage ovarian cancer patients using the peritoneal carcinomatosis index, detected by CT (CT-PCI), correlates with the serum levels of tumor marker CA-125 and 5-year survival. METHODS: The CT-PCI was determined in 82 patients with stage III or stage IV ovarian cancer using the Sugarbaker classification prior to cytoreductive surgery. Linear regression analysis was used to correlate CT-PCI and CA-125 levels. Correlation of presurgical CT-PCI, optimal surgical cytoreduction, and 5-year survival was established using binary logistic regression analysis. A score for prediction of 5-year survival probability was established using multivariate backwards binary logistic regression. RESULTS: Presurgical CT-PCI correlates significantly with presurgical CA-125 serum levels (r = 0.487, P < 0.001). Multivariate binary logistic regression suggested significantly improved 5-year survival with lower CT-PCI and lower ECOG performance scores. CONCLUSION: CT-PCI allows quantification of peritoneal disease in advanced-stage ovarian cancer patients, similar to CA-125. CT-PCI in combination with ECOG performance has the potential to help evaluate the 5-year survival probability.

Safety and Effectiveness of SAF-R, a Novel Patient Positioning Device for Robot-Assisted Pelvic Surgery in Trendelenburg Position.

PURPOSE: We found current robotic positioning devices to be inadequate and cumbersome. Furthermore, we realized there were no premarket well-designed studies to prove their safety and efficacy. In this prospective pilot study, we aimed to investigate the safety and effectiveness of a novel patient-positioning device (SAF-R) to secure the patient in Trendelenburg (T-burg) position for robot-assisted pelvic surgery. PATIENTS AND METHODS: Sixteen patients undergoing robot-assisted pelvic operation in T-burg position were enrolled. Patients were positioned using SAF-R board. Pressure sensor mats were used for real-time monitoring of the contact pressures and contact area on the shoulders and calves throughout the surgery. Data collection included patients' body mass index (BMI), time needed for positioning, total time in the T-burg position, contact pressure and contact area readings from the sensor mats, and the patient shifting distance on the table. Patients were also followed for 1-month postoperatively for any position-related adverse event. RESULTS: The median age of the patients was 56.5 years with median BMI of 27.3. The median positioning time was 6 minutes, duration of T-burg position was 3.5 hours, and patient shift on the table was 1 cm. The contact pressure over the shoulders was in the safe range (< 80 mm Hg) before and at the end of the surgery in all cases (right: 13.12 ± 1.12 vs 20.25 ± 1.56 mm Hg, left: 12.84 ± 1.05 vs 19.60 ± 1.09 mm Hg, p = 0.001). The changes in the mean contact pressure over the calves and the mean contact area for the shoulders and calves during the T-burg position were not significantly different. No significant position-related complication was detected during follow-up. CONCLUSIONS: SAF-R surgical board is a safe, reliable, and timesaving positioning device for patients undergoing robotic pelvic surgery in the T-burg position.

Drainage-related ultrasonography (DRUS): a novel technique for discriminating obstructive and nonobstructive hydroureters in children.

BACKGROUND: Despite advances in urologic imaging, the paucity of an optimal technique that accurately clarifies obstructive and nonobstructive hydroureter exists. OBJECTIVE: This study was conducted to introduce a novel and modified ultrasonographic technique, known as drainage-related ultrasonography (DRUS), discriminating obstructive and nonobstructive, nonrefluxing hydroureter. MATERIALS AND METHODS: A total of 358 children (mean age, 3.7 years) with 418 nonrefluxing hydroureter were included. These children were composed of two groups of obstructive nonrefluxing (141 children with 157 dilated ureters) and nonobstructive, nonrefluxing (217 children with 261 hydroureter). The definite diagnosis regarding the subtype of hydroureter was derived from appropriate investigation. The maximum diameter of the dilated ureter, which was observed on ultrasonography, was recorded before and after 3 h of catheterization, as D1 and D2, respectively. To assess the D ratio, a formula was developed, that is, [(|D1 - D2|)/D1] × 100. Values were recorded and cutoff points were set to discriminate between subtypes. RESULTS: Obstructive versus nonobstructive subtypes of nonrefluxing hydroureter were clarified with 78.5 % sensitivity and 83.4 % specificity, by setting a cutoff point of 22 % for the D ratio. Regardless of the cutoff point assigned to the reduction in D (D2 compared with D1), DRUS revealed 93.9 % sensitivity, 80.6 % specificity, 63.2 % positive predictive value, and 97.4 % negative predictive value in discriminating upper from lower obstruction. CONCLUSION: DRUS affords favorable results in terms of differentiating between obstructive and nonobstructive, nonrefluxing hydroureter, as well as between upper and lower obstruction in obstructive cases. It has the potential to become an efficient imaging modality in the diagnostic algorithm of hydroureter.

Predictive Value of Chemical-Shift MRI in Distinguishing Clear Cell Renal Cell Carcinoma From Non-Clear Cell Renal Cell Carcinoma and Minimal-Fat Angiomyolipoma.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic performance of chemical-shift MRI in the differentiation of clear cell renal cell carcinoma (RCC) from minimal-fat angiomyolipoma (AML) and non-clear cell RCC. MATERIALS AND METHODS: In this retrospective study, 97 patients with solid renal tumors without macroscopic fat and with a pathologic diagnosis of clear cell RCC (n = 40), non-clear cell RCC (n = 31), or minimal-fat AML (n = 26) who had undergone renal chemical-shift MRI were included. Size, location, morphology, and signal intensity (SI) of the tumors and the contralateral normal kidneys on T2-weighted and in-phase and opposed-phase images were recorded by readers blinded to the pathology. Percentage tumor-to-renal parenchymal SI drop (percentage SI drop) was calculated and correlated to tumor histology. The statistical analysis was done using Kruskal-Wallis, one-way ANOVA, chi-square, and Fisher exact tests. RESULTS: The percentage SI drop was significantly higher in clear cell RCC compared with non-clear cell RCC and minimal-fat AML (p < 0.001). Percentage SI drop of greater than 20% had 57.5% sensitivity, 96.5% specificity, and 92% positive predictive value (PPV); and percentage SI drop greater than 29% had 40% sensitivity and 100% specificity for diagnosis of clear cell RCC within the cohort of clear cell RCC, minimal-fat AML, and non-clear cell RCC. A significant proportion of minimal-fat AML (46.2%) displayed homogeneous low T2-weighted SI as opposed to clear cell RCC (5%) and non-clear cell RCC (29%) (p < 0.001). CONCLUSION: The percentage SI drop on chemical-shift MRI had high specificity and moderate sensitivity in predicting clear cell RCC over non-clear cell RCC and minimal-fat AML. A percentage SI drop greater than 20% in a renal mass without macroscopically visible fat has high PPV for clear cell RCC over minimal-fat AML and non-clear cell RCC. Among morphologic features, homogeneous low T2 SI favors minimal-fat AML over RCC.

Bladder reconstruction using scaffold-less autologous smooth muscle cell sheet engineering: early histological outcomes for autoaugmentation cystoplasty.

OBJECTIVE: To investigate the feasibility of a new approach for cystoplasty using autologous smooth muscle cell (SMC) sheet and scaffold-less bladder tissue engineering with the main focus on histological outcomes in a rabbit model. MATERIALS AND METHODS: In all, 24 rabbits were randomly divided into two groups. In the experimental group, SMCs were obtained from the bladder muscular layer, labelled with PKH-26, and seeded on temperature-responsive culture dishes. Contiguous cell sheets were noninvasively harvested by reducing the temperature and triple-layer cell-dense tissues were constructed. After partial detrusorectomy, the engineered tissue was transplanted onto the urothelial diverticulum. The control group underwent partial detrusorectomy followed by peritoneal fat coverage. At 2, 4, and 12 weeks the rabbits were humanely killed and haematoxylin and eosin, Masson's trichrome, cluster of differentiation 34 (CD34), CD31, CD3, CD68, α-smooth muscle actin (α-SMA), picrosirius red, and pentachrome staining were used to evaluate bladder reconstruction. RESULTS: At 2 weeks after SMC-sheet grafting, PKH-26 labelled SMCs were evident in the muscular layer. At 4 weeks, 79.1% of the cells in the muscular layer were PKH-positive cells. The portion of the muscular layer increased in the experimental group during the follow-up and was similar to normal bladder tissue after 12 weeks. α-SMA staining showed well organised muscle at 4 and 12 weeks. CD34+ endothelial progenitor cells and CD31+ microvessels increased continuously and peaked 4 and 12 weeks after grafting, respectively. CONCLUSION: In the present study, we show that autologous SMC-sheet grafting has the potential for reliable bladder reconstruction and is technically feasible with a favourable evolution over the 12 weeks following implantation. Our findings could pave the way toward future bladder tissue engineering using the SMC-sheet technique.

Magnetic resonance imaging of pelvic metastases in male patients.

Magnetic resonance (MR) imaging offers a noninvasive tool for diagnosis of primary and metastatic pelvic tumors. The diagnosis of a pelvic metastatic lesion implies an adverse prognosis and dictates the management strategies. Knowledge of normal MR imaging anatomy of the pelvis and the signal characteristics of normal and abnormal structures is essential for accurate interpretation of pelvic MR imaging. This article reviews imaging manifestations of nodal, visceral, and musculoskeletal metastatic lesions of the pelvis along with current and evolving MR imaging techniques.

Enhanced primary tumor delineation in pancreatic adenocarcinoma using ultrasmall super paramagnetic iron oxide nanoparticle-ferumoxytol: an initial experience with histopathologic correlation.

PURPOSE: To evaluate the role of ferumoxytol-enhanced magnetic resonance imaging (MRI) in delineating primary pancreatic tumors in patients undergoing preoperative neoadjuvant therapy. MATERIALS AND METHODS: Eight patients with pancreatic adenocarcinoma were enrolled in this study, and underwent MRI scans at baseline, immediate post, and at the 48 hour time point after ferumoxytol injection with quantitative T2* sequences. The patients were categorized into two groups; group A received preoperative neoadjuvant therapy and group B did not. The T2* of the primary pancreatic tumor and adjacent parenchyma was recorded at baseline and the 48 hour time point. After surgery, the primary tumors were assessed histopathologically for fibrosis and inflammation. RESULTS: The mean T2* of the primary tumor and adjacent parenchyma at 48 hours in group A were 22.11 ms and 16.34 ms, respectively; in group B, these values were 23.96 ms and 23.26 ms, respectively. The T2* difference between the tumor and adjacent parenchyma in group A was more pronounced compared to in group B. The tumor margins were subjectively more distinct in group A compared to group B. Histopathologic evaluation showed a rim of dense fibrosis with atrophic acini at the periphery of the lesion in group A. Conversely, intact tumor cells/glands were present at the periphery of the tumor in group B. CONCLUSION: Ferumoxytol-enhanced MRI scans in patients receiving preoperative neoadjuvant therapy may offer enhanced primary tumor delineation, contributing towards achieving disease-free margin at the time of surgery, and thus improving the prognosis of pancreatic carcinomas.

The application of tissue-engineered preputial matrix and fibrin sealant for urethral reconstruction in rabbit model.

BACKGROUND: To introduce the role of fibrin sealant and preputial acellular matrix (PAM) as a new source of inert collagen matrix for urethral reconstruction. METHODS: A ventral urethral segmental defect was created in 24 male rabbits divided into four groups. In group 1 (G1), urethrotomy was closed in layers. In group 2 (G2), closure was followed by applying fibrin sealant. In groups 3 (G3) and 4 (G4), urethroplasty was performed with a patch graft of PAM, and in G4, fibrin sealant was also applied. Serial urethrography was performed before and after the operation. Then, the animals were euthanized, and their urethra was excised 1, 3, and 9 months postoperatively for further electron microscopic examination, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) technique, and immunohistochemical (IHC) staining with CD34, CD31, desmin, SMA, and α-actin. RESULTS: In G1 and G2, the fistula repair failed in all the time points. In G3 and G4, serial urethrography confirmed the maintenance of a wide urethral caliber without signs of strictures or extravasations. Satisfactory vascularity was observed in G3 and G4 during the whole study, which was more significant in G4 after 9 months of follow-up. The presence of a complete transitional cell layer was confirmed over the graft in G3 and G4 in all time points. IHC staining confirmed the effectiveness of fistula repair in G3 and G4, 3 months postoperatively. CONCLUSION: This rabbit model showed that PAM combined with fibrin sealant may herald a reliable option for repairing segmental urethral defects.

MDCT imaging of Alloderm biologic mesh spacers in the abdomen and pelvis--preliminary experience.

The purpose of this study was to assess the attenuation characteristics of the Alloderm Biologic Mesh Spacer (ABMS) in the abdomen and pelvis. Of nine patients with ABMS, five underwent multidetector computed tomographic scans at 1, 4, and 7 months postsurgery. Two patients underwent positron emission tomography-computed tomography (PET-CT). The pre- and postcontrast images were evaluated for attenuation characteristics of ABMS. The PET-CT scans were reviewed for [18F]-fluorodeoxyglucose (FDG) uptake. We observed increase in the attenuation characteristics of the spacers on follow-up imaging (P<.05). No FDG uptake was noted on PET-CT. To conclude, ABMS demonstrates soft tissue attenuation on noncontrast CT and shows increase attenuation on serial CT scans.

Depiction of celiac ganglia on positron emission tomography and computed tomography in patients with lung cancer.

OBJECTIVE: To differentiate imaging characteristics of celiac ganglia from metastatic lesion on positron emission tomography-computed tomography (PET-CT) in patients with lung cancer and correlate these findings to postmortem multidetector row computed tomography (MDCT). METHODS: One hundred twenty-nine patients were included. Imaging characteristics and fluorodeoxyglucose (FDG) avidity of the celiac ganglia were recorded. Postmortem MDCT of 20 subjects were reviewed. RESULTS: Celiac ganglia were identified unilaterally in 127 and bilaterally in 108 patients without abnormal FDG uptake. Postmortem images showed celiac ganglia in all cases with no significant difference compared to our patients. CONCLUSIONS: Familiarity with CT characteristics and FDG-avidity of celiac ganglia enable us to distinguish them from metastatic lesions in their vicinity.

Anal sphincter repair with muscle progenitor cell transplantation: serial assessment with iron oxide-enhanced MRI.

OBJECTIVE: The purpose of this study was to assess homing of ultrasmall superparamagnetic iron oxide (USPIO)-labeled muscle progenitor cells in an experimental rabbit model of anal sphincter repair using MRI. MATERIALS AND METHODS: Twelve rabbits underwent external anal sphincterotomy and randomly received injection of either autologous muscle progenitor cells labeled with USPIO at a concentration of 4 mg/10(6) cells (experimental group) or saline (control group) at the site of sphincter damage. In vivo MRI, electromyography, and manometry were performed before, 1 hour after, and 1, 2, and 4 weeks after the injection. At the end time point, anal sphincter sections were obtained for histologic analysis. Semiquantitative analysis of fibrosis, desmin, iron, CD3, and CD68 was performed using two microscopic fields in two distinct regions of the sphincter according to either presence (zone I) or absence (zone II) of signal loss on the corresponding MR images. RESULTS: Labeling efficiency was 88.67% and did not influence cell viability. On follow-up images of the cell-transplanted rabbits, significant influence was reported at 1 hour, 1 and 2 weeks after transplantation. The maximum signal loss was detected at 1 hour (75.7%). Regenerating myofibers stained positively for desmin and mainly correlated to zone I on MR images. Clusters of iron-positive particles were detectable in the myofibers located mainly at the site of injection, which correlated well to zone I. Significant signal loss and Perls Prussian blue-positive area were not detected in the control group. Functional studies showed significant improvement in sphincter pressure and electrical activity in the experimental group after 4 weeks (p<0.001). CONCLUSION: Our results support the potential of iron oxide-enhanced MRI for serial monitoring of transplanted cells in an animal model of anal sphincter repair.

Cystic renal cell carcinomas: do they grow, metastasize, or recur?

OBJECTIVE: The purpose of this study is to evaluate the interval growth, tumor recurrence, and metastatic disease occurrence of cystic renal cell carcinoma (RCC). MATERIALS AND METHODS: Pre-and posttreatment imaging of 47 histologically proven cystic RCCs, with at least 6 months of pretreatment imaging monitoring or at least 2 years of posttreatment imaging follow-up, or both, was retrospectively reviewed. Tumor morphologic features, preoperative growth, histologic typing and grading, and the incidence of tumor recurrence or metastasis were evaluated. Growth rate of tumors were compared among various histologic subtypes and Fuhrman grades. RESULTS: Of 47 tumors, 27 (57.5%) were clear cell RCCs, 12 (25.5%) were multilocular RCCs, and eight (17%) were papillary cystic RCCs. Overall, 26 (55.3%) tumors were graded as Fuhrman grade 2, 17 (36.1%) were Fuhrman grade 1, and one tumor was Fuhrman grade 3. Of the 26 tumors with a minimum of 6 months of pretreatment imaging monitoring, 19 (73%) did not show a significant increase in tumor size. The differences in mean growth among the Fuhrman grades and different subtypes were not statistically significant. The average duration of posttreatment follow-up was 51 months. There were no local recurrences among the 43 patients who underwent posttreatment imaging, except for one patient who had metastasis at preoperative clinical presentation. CONCLUSION: Cystic RCCs exhibit slow indolent growth, if any, and show no significant metastatic or recurrence potential, with excellent clinical outcomes. We raise the need for revisiting current imaging protocols that may involve frequent pre-and posttreatment imaging in cystic RCCs.

The spectrum of IgG4-related disease in the abdomen and pelvis.

OBJECTIVE: IgG4-related disease was not recognized as a specific clinical entity until 2003 when extrapancreatic lesions were reported in patients with autoimmune pancreatitis. IgG4-related disease is characterized by elevated serum IgG4 levels and infiltration of the target organ by IgG4-positive plasma cells. The complete gamut of visceral involvement is still being outlined. The purpose of this article is to highlight the plethora of lesions under the spectrum of IgG4-related disease of the abdomen and pelvis, describe their imaging appearances on multimodality cross-sectional imaging, and discuss the differential diagnoses. CONCLUSION: It is important for radiologists to recognize the multiorgan involvement and few classic features of IgG4-related disease that often tend to simulate malignancy.

Imaging behavior of the normal adrenal on ferumoxytol-enhanced MRI: preliminary findings.

OBJECTIVE: Ultrasmall superparamagnetic iron oxide nanoparticles, such as ferumoxytol, produce decreased MR signal on susceptibility-inducing T2*-weighted sequences in tissues of the reticuloendothelial system. However, acute iron deposition in the adrenals has not been reported. The purpose of this article is to report our initial observations of the imaging behavior of the normal adrenals on ferumoxytol-enhanced T2*-weighted magnetic resonance imaging. SUBJECTS AND METHODS: Quantitative T2* imaging was performed at 3 T using a breath-hold monopolar multiecho gradient echo sequence with six equally spaced in-phase echoes in nine patients. Changes in signal-to-noise ratio (SNR) were analyzed prior to and 48 hours after ferumoxytol administration in the adrenals, liver and spleen (positive controls), and pancreas and skeletal muscle (negative controls). RESULTS: In comparison with unenhanced images, there was an average SNR decrease of 67.4% in the right adrenal, 77.6% in the left adrenal, 68.4% in the liver, 89.1% in the spleen, 15.0% in the pancreas, and 9.5% in skeletal muscle on T2*-weighted images obtained 48 hours after ferumoxytol administration. The decrease in SNR observed in the adrenals was significantly greater than that seen in the pancreas and skeletal muscle (left adrenal, p < 0.0001; right adrenal, p = 0.0002) and similar to that seen in the liver and spleen. CONCLUSION: The normal adrenal loses signal on ferumoxytol-enhanced T2*-weighted MRI. Acute iron deposition within the adrenals has not been previously described. The mechanism of ferumoxytol uptake in the adrenal and potential clinical applications warrant further investigation.