Development and validation of a prognostic prediction model including the minor lymphatic pathway for distant metastases in cervical cancer patients.

To develop and validate a prognostic model, including the minor lymphatic pathway (internal iliac and presacral nodes). STUDY DESIGN: Retrospective cohort. PARTICIPANTS: Locally advanced cervical cancer underwent concurrent chemoradiotherapy. SAMPLE SIZE: 397 and 384 patients in the development and validation data set. PREDICTORS: Our new nodal staging system with the minor lymphatic pathway. OUTCOME: Distant metastases. STATISTICAL ANALYSIS: Cox regression; net reclassification improvement (NRI) and decision curve analysis (DCA). Our new nodal system was the strongest predictor. The predictors in the final model were new nodal system, tumor stage, adenocarcinoma, initial hemoglobin, tumor size and age. The nodal system and the pretreatment model had concordance indices of 0.661 and 0.708, respectively, with good calibration curves. Compared to the OUTBACK eligibility criteria, the nodal system showed NRI for both cases (22%) and controls (16%). The pretreatment model showed NRI for cases (31%) and controls (18%). DCA in both models showed threshold probability of 15% and 12%, respectively, when compared with 24% in OUTBACK eligibility criteria. Our new nodal staging system and the pretreatment model could differentiate between high-risk and low-risk patients, thus facilitating decisions to provide more aggressive treatment to prevent distant metastases.

Evaluation and external validation of minor lymphatic pelvic pathway for distant metastases in cervical cancer patients treated with concurrent chemoradiotherapy.

To evaluate and validate the minor lymphatic pathway for distant metastases in cervical cancer. This is a retrospective cohort of cervical cancer patients underwent curative concurrent chemoradiotherapy. We used original dataset from 1 university hospital and validation dataset from 3 university hospitals. Lymphadenopathy status in CT imaging was reviewed by radiologist in either the obturator and external iliac nodes (major pathway) or the internal iliac and presacral nodes (minor pathway). We then used Cox regression to adjust for all potential confounders, including paraaortic nodes, T stage, histology, age, total treatment time, total number of nodes, total short axis of nodes. 397 and 384 patients were in the original and validation datasets (median follow-up period, 59.5 month's). The minor pathway was independent prognostic factor in multivariable analysis [HR=2.64; 95%CI=1.07-6.55; P = 0.036] and [HR=14.84; 95%CI=3.15-70.01; P= 0.001] in original and validation datasets, respectively. Whereas, the major pathway was statistically non-significant. Further validation showed that the minor pathway had the highest HR for distant metastases with both the EMBRACE (HR=6.05; 95% CI=1.30-28.08; P = 0.022) and the FIGO 2018 (HR=7.43; 95% CI=2.94-18.78; P<0.001) in the original dataset. A similar result was found with the validation dataset: EMBRACE, HR=30.91; 95% CI=2.78-343.62; P = 0.005; and FIGO 2018, HR=42.41; 95% CI=8.83-203.60; P<0.001.This is the first clinical study to validate that the minor lymphatic pathway was predominantly associated with distant metastases in cervical cancer. This finding should be validated in larger cohort to further integrate in standard staging for prediction of distant metastases.

Diffusion-weighted magnetic resonance imaging for the assessment of liver fibrosis in chronic viral hepatitis.

BACKGROUND: Accurate noninvasive methods for the assessment of liver fibrosis are urgently needed. This prospective study evaluated the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DWI) for the staging of liver fibrosis and proposed a diagnostic algorithm using DWI to identify cirrhosis in patients with chronic viral hepatitis. METHODS: One hundred twenty-one treatment-naïve patients with chronic hepatitis B or C were evaluated with DWI followed by liver biopsy on the same day. Breath-hold single-shot echo-planar DWI was performed to measure the apparent diffusion coefficient (ADC) of the liver and spleen. Normalized liver ADC was calculated as the ratio of liver ADC to spleen ADC. RESULTS: There was an inverse correlation between fibrosis stage and normalized liver ADC (p<0.05). For the prediction of fibrosis stage ≥2, stage ≥3, and cirrhosis, the area under the receiver-operating curve of normalized liver ADC was 0.603, 0.704, and 0.847, respectively. The normalized liver ADC value ≤1.02×10-3 mm2/s had 88% sensitivity, 81% specificity, 25% positive predictive value (PPV), and 99% negative predictive value (NPV) for the diagnosis of cirrhosis. Using a sequential approach with the Fibrosis-4 index followed by DWI, normalized liver ADC ≤1.02×10-3 mm2/s in patients with Fibrosis-4 >3.25 yielded an 80% PPV for cirrhosis, and a 100% NPV to exclude cirrhosis in patients with Fibrosis-4 between 1.45 and 3.25. Only 15.7% of patients would require a liver biopsy. This sequential strategy can reduce DWI examinations by 53.7%. CONCLUSION: Normalized liver ADC measurement on DWI is an accurate and noninvasive tool for the diagnosis of cirrhosis in patients with chronic viral hepatitis.

Predictive significance of cancer related-inflammatory markers in locally advanced rectal cancer.

BACKGROUND: Locally advanced rectal cancer is treated using neoadjuvant chemoradiation (nCRT), followed by total mesorectal excision (TME). Tumor regression and pathological post-treatment stage are prognostic for oncological outcomes. There is a significant correlation between markers representing cancer-related inflammation, including high neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte (MLR) and unfavorable oncological outcomes. However, the predictive role of these markers on the effect of chemoradiation is unknown. AIM: To evaluate the predictive roles of NLR, MLR, and PLR in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiation. METHODS: Patients (n = 111) with locally advanced rectal cancer who underwent nCRT followed by TME at the Minimally Invasive Surgery Unit, Siriraj Hospital between 2012 and 2018 were retrospectively analyzed. The associations between post-treatment pathological stages, neoadjuvant rectal (NAR) score and the pretreatment ratios of markers of inflammation (NLR, MLR, and PLR) were analyzed. RESULTS: Clinical stages determined using computed tomography, magnetic resonance imaging, or both were T4 (n = 16), T3 (n = 94), and T2 (n = 1). The NAR scores were categorized as high (score > 16) in 23.4%, intermediate (score 8-16) in 41.4%, and low (score < 8) in 35.2%. The mean values of the NLR, PLR, and MLR correlated with pathological tumor staging (ypT) and the NAR score. The values of NLR, PLR and MLR were higher in patients with advanced pathological stage and high NAR scores, but not statistically significant. CONCLUSION: In patients with locally advanced rectal cancer, pretreatment NLR, MLR and PLR are higher in those with advanced pathological stage but the differences are not significantly different.

Female urinary retention from a huge periurethral mass caused by immunoglobulin G4-related disease (IgG4-RD).

Immunoglobulin G4-related disease is a systemic disease, recognized as extensive T-lymphocyte and IgG4-positive plasma cells. It can present as inflammatory pseudotumor in various organs. A female 75 years old, diagnosed IgG4-related autoimmune pancreatitis, presented with urinary retention. Pelvic examination showed well-defined, soft tissue mass, bulging from anterior vaginal wall. MRI pelvis demonstrated a huge periurethral mass, size 6.2 × 4.4 × 4.2 cm, encasing the urethra, extending from bladder neck to distal urethra, and mimicking the prostate gland. Tissue biopsy showed compatible with IgG4-related disease. Immunosuppresive drugs were given for few months and the patient could void normally.

Diagnostic performance of qualitative and quantitative shear wave elastography in differentiating malignant from benign breast masses, and association with the histological prognostic factors.

BACKGROUND: To determine the diagnostic performance of qualitative and quantitative shear wave elastography (SWE) and the optimal cutoff values of the quantitative SWE parameters in differentiating malignant from benign breast masses, and to evaluate the association between the quantitative SWE parameters and histological prognostic factors. METHODS: A gray scale ultrasound and SWE were prospectively performed on a total of 244 breast masses (148 benign, and 96 malignant) in 228 consecutive patients before an ultrasound-guided needle biopsy. The qualitative SWE and quantitative SWE parameters (the mean elasticity, maximum elasticity, and elasticity ratio) were measured in each mass. The diagnostic performance of SWE and the optimal cutoff values of the quantitative SWE parameters were obtained. An association analysis of the parameters and histological prognostic factors was performed. RESULTS: The malignant masses had a more heterogeneous pattern on the qualitative SWE than benign masses (P<0.001). The quantitative SWE parameters of the malignant masses were higher than those of the benign masses (P<0.001); the mean elasticity, maximum elasticity, and elasticity ratio of the benign masses were 19.73 kPa, 23.98 kPa, and 2.78, respectively; and the mean elasticity, maximum elasticity, and elasticity ratio of the malignant masses were 88.13 kPa, 98.48 kPa, and 10.64, respectively. The optimal cutoff value of the mean elasticity was 30 kPa, of the maximum elasticity was 36 kPa, and of the elasticity ratio was 4.5. The maximum elasticity had the highest AUC. Combining the three SWE parameters to differentiate between the malignant and benign masses increased the negative predictive value (NPV), which correctly downgraded 72.73% of BI-RADS category 4A masses to BI-RADS category 3. No statistically significant association was found between the quantitative SWE parameters and the tumor grading, tumor types, axillary lymph node statuses, or molecular subtypes of the breast cancers (P>0.05). CONCLUSIONS: The qualitative and quantitative SWE provided good diagnostic performance in differentiating malignant and benign masses. The maximum elasticity of the quantitative SWE parameters had the best diagnostic performance. Adding the three combined quantitative SWE parameters to the BI-RADS category 4A masses potentially downgraded them to BI-RADS category 3 and avoided unnecessary biopsies. No statistically significant association was found between the quantitative SWE parameters and the histological prognostic factors.

Clinical, mammographic, and ultrasonographic characteristics of diabetic mastopathy: A case series.

PURPOSE: Diabetic mastopathy (DMP) is a rare benign breast lesion that mimics breast cancer on ultrasound. Our aims were to identify patient characteristics and imaging features of the disease. METHODS: We conducted retrospective searches of our database for DMP lesions that were pathologically confirmed between January 2004 and November 2015. Mammographic and ultrasound features were reviewed by two experienced radiologists. RESULTS: Twelve women were identified with 16 lesions. Most patients (83%) had type 2 diabetes mellitus (DM) and over half were insulin-dependent (58.3%), with a mean time of 16.9 years between the diagnosis of DM and that of DMP. There were negative findings on mammography for 46.7% of the lesions, including larger-sized lesions. Ultrasound revealed various features, including irregular shape (81.3%), indistinct margins (100%), parallel orientation to the chest wall (93.8%), marked hypoechogenicity (87.5%), and posterior shadowing (62.5%). CONCLUSIONS: DMP was more common in patients with longstanding DM; in particular, type 2 DM and insulin-dependent patients. DMP lesions were usually occult on mammography, despite the relatively large size of DMP, which may help distinguish DMP from invasive cancer. Ultrasound detected several features that are also present in invasive cancer, making tissue sampling necessary to distinguish these.

Characterization of renal stone composition by using fast kilovoltage switching dual-energy computed tomography compared to laboratory stone analysis: a pilot study.

PURPOSE: To prospectively examine the diagnostic performance of fast kilovoltage switching dual-energy computed tomography (DECT) in characterization of in vivo renal stone composition compared with postoperative stone analysis. METHODS: Consecutive consenting patients scheduled for endoscopic kidney stone surgery in a tertiary referral hospital from June 2015 to January 2016 were enrolled. Patients were preoperatively scanned with single-source, fast kilovoltage switching DECT. Stone compositions were determined regarding the effective atomic number measurements. Results of the stone compositions from DECT were compared to postoperative infrared spectroscopy stone analysis as the standard reference. RESULTS: For the 39 patients enrolled in the study, DECT was able to detect uric acid stone with sensitivity of 88.9% and specificity of 100%. There was 100% positive predictive value, 96.8% negative predictive value, and 97.4% accuracy. For non-contrast CT scan, sensitivity was 88.9%, specificity was 96.7%, positive predictive value was 88.9%, negative predictive value was 96.7%, and accuracy was 94.8%. Of the 39 samples examined, 21 (54%) were single composition, whereas 18 (46%) were combined. Single composition stones were correctly characterized by DECT in 100% (8/8) for uric acid. Whereas the result of uric acid stone containing stone discrimination in mixed composition was not so good with Zeff alone, iodine imaging can compensated this fault. CONCLUSIONS: DECT provides excellent accuracy in characterizing uric acid stone compositions. With the addition of iodine image, all of uric acid-containing stones can be determined by the DECT.

An Automated Segmentation of R2* Iron-Overloaded Liver Images Using a Fuzzy C-Mean Clustering Scheme.

OBJECTIVES: The objectives of this study were to develop and test an automated segmentation of R2* iron-overloaded liver images using fuzzy c-mean (FCM) clustering and to evaluate the observer variations. MATERIALS AND METHODS: Liver R2* images and liver iron concentration (LIC) maps of 660 thalassemia examinations were randomly separated into training (70%) and testing (30%) cohorts for development and evaluation purposes, respectively. Two-dimensional FCM used R2* images, and the LIC map was implemented to segment vessels from the parenchyma. Two automated FCM variables were investigated using new echo time and membership threshold selection criteria based on the FCM centroid distance and LIC levels, respectively. The new method was developed on a training cohort and compared with manual segmentation for segmentation accuracy and to a previous semiautomated method, and a semiautomated scheme was suggested to improve unsuccessful results. The automated variables found from the training cohort were assessed for their effectiveness in the testing cohort, both quantitatively and qualitatively (the latter by 2 abdominal radiologists using a grading method, with evaluations of observer variations). A segmentation error of less than 30% was considered to be a successful result in both cohorts, whereas, in the testing cohort, a good grade obtained from satisfactory automated results was considered a success. RESULTS: The centroid distance method has a segmentation accuracy comparable with the previous-best, semiautomated method. About 94% and 90% of the examinations in the training and testing cohorts were automatically segmented out successfully, respectively. The failed examinations were successfully segmented out with thresholding adjustment (3% and 8%) or by using alternative results from the previous 1-dimensional FCM method (3% and 2%) in the training and testing cohorts, respectively. There were no failed segmentation examinations in either cohort. The intraobserver and interobserver variabilities were found to be in substantial agreement. CONCLUSIONS: Our new method provided a robust automated segmentation outcome with a high ease of use for routine clinical application.

MRI of placenta percreta: differentiation from other entities of placental adhesive disorder.

OBJECTIVES: To retrospectively review the MRI findings of placenta percreta and identify those helpful for differentiation from non-placenta percreta. MATERIALS AND METHODS: The MRI images of 21 patients with a preliminary diagnosis of placental adhesive disorder scanned between 2005 and 2014 were evaluated. Radiologists blinded to the final diagnosis evaluated six previously described MRI findings of placenta adhesive disorder. The sensitivity, specificity, accuracy, negative predictive value (NPV), and positive predictive value (PPV) of MRI for the diagnosis of placenta percreta were also calculated. RESULTS: The study included 12 cases of placenta percreta and 9 cases of non-placenta percreta. Invasion of placental tissue outside the uterus was found only in placenta percreta (p = 0.045; sensitivity 41.7 %; specificity 100 %). All placenta percreta cases also had a moderate to marked degree of heterogeneous placental signal intensity (p = 0.063; sensitivity 100 %; specificity 33.3 %). The size of the dark bands on T2-weighted imaging, and the presence of disorganized intra-placental vessels, showed no statistically significant difference between placenta percreta and non-placenta percreta. The sensitivity, specificity, NPV, PPV, and accuracy of MRI for detection of placenta percreta were 91.7, 44, 80, 68, and 71.4 %, respectively. CONCLUSIONS: MRI is recommended for the evaluation of placenta percreta, with the most specific signs including the invasion of placental tissue outside the uterus on B-FFE sequences, and consideration of the degree of placental signal heterogeneity. The size of the T2 dark band alone, or bizarre disorganized intra-placental vessels, did not correlate with the severity of invasion.

Nephrogenic systemic fibrosis risk after liver magnetic resonance imaging with gadoxetate disodium in patients with moderate to severe renal impairment: results of a prospective, open-label, multicenter study.

OBJECTIVE: The objective of this study was to assess the risk of gadoxetate disodium in liver imaging for the development of nephrogenic systemic fibrosis (NSF) in patients with moderate to severe renal impairment. MATERIALS AND METHODS: We performed a prospective, multicenter, nonrandomized, open-label phase 4 study in 35 centers from May 2009 to July 2013. The study population consisted of patients with moderate to severe renal impairment scheduled for liver imaging with gadoxetate disodium. All patients received a single intravenous bolus injection of 0.025-mmol/kg body weight of liver-specific gadoxetate disodium. The primary target variable was the number of patients who develop NSF within a 2-year follow-up period. RESULTS: A total of 357 patients were included, with 85 patients with severe and 193 patients with moderate renal impairment, which were the clinically most relevant groups. The mean time period from diagnosis of renal disease to liver magnetic resonance imaging (MRI) was 1.53 and 5.46 years in the moderate and severe renal impairment cohort, respectively. Overall, 101 patients (28%) underwent additional contrast-enhanced MRI with other gadolinium-based MRI contrast agents within 12 months before the start of the study or in the follow-up. No patient developed symptoms conclusive of NSF within the 2-year follow-up. CONCLUSIONS: Gadoxetate disodium in patients with moderate to severe renal impairment did not raise any clinically significant safety concern. No NSF cases were observed.

Benefit of double contrast MRI in diagnosis of hepatocellular carcinoma in patients with chronic liver diseases.

OBJECTIVE: To assess the benefit on diagnosis of hepatocellular carcinoma (HCC) in patients with chronic liver disease or cirrhosis with double contrast MR imaging compared to the routine gadolinium-based MR imaging. MATERIAL AND METHOD: Seventy-one consecutive patients with cirrhosis or chronic hepatitis underwent multiphase, gadolinium-enhanced liver MRI examination and sequentially superparamagnetic iron oxide (SPIO)-enhanced images. The presence signal intensities of lesions on non-contrast sequences, dynamic gadolinium-enhanced images and delayed 10-min post-SPIO T2*-weighted images were recorded. RESULTS: Among 27 patients, 15 HCCs from 12 patients were diagnosed by surgical (n = 7) and non-surgical (n = 8) proofs. The overall sensitivity, specificity, positive predictive value, and negative predictive value of double contrast-enhanced images in 12 patients were 83.3% (95% CI: 58.5, 96.2), 33.3% (95% CI: 5.4, 88.4), 88.2% (95% CI: 63.5, 98.2), and 25% (95% CI: 4.1, 79.6) and these of gadolinium-enhanced images were 72.2% (95% CI: 46.5, 90.2), 33.3% (95% CI: 5.4, 88.4), 86.6% (95% CI: 59.5, 97.9), and 16.6% (95% CI: 2.7, 63.9), respectively. There were two benign hepatic nodules (1 adenoma, 1 dysplastic nodule) suspected as HCCs on MR images and two surgically proven-HCCs, invisible on gadolinium-enhanced images, detected as defect on only delayed 10-min post-SPIO T2*-weighted images. CONCLUSION: SPIO-enhanced images in double contrast-enhanced MR imaging had an additional value on HCC detection, compared to gadolinium-enhanced MR imaging, in patients with chronic liver disease or cirrhosis.

Improving breast cancer detection using ultrasonography in asymptomatic women with non-fatty breast density.

BACKGROUND: Mammography (MX) is a reliable modality for detection of breast cancer in asymptomatic women. Use of additional whole breast ultrasonography (US) for breast cancer screening is widely recognized, in particular in women with dense breast parenchyma. PURPOSE: To determine the subgroup of women, according to breast density and age, who receive most benefit from US following MX for detection of breast cancer in an asymptomatic condition. MATERIAL AND METHODS: The study was conducted in asymptomatic women who had non-fatty breast parenchyma using MX and US during January 2006 and December 2007. Mammographic breast density was classified as recommended by ACR BI-RADS lexicon. Non-fatty breast referred to D2, D3, and D4. US was performed by the same radiologists who interpreted MX with a handheld machine during the same visit. Data on demographics, cancer detection rate (CDR), and incremental cancer detection rate (ICDR) were analyzed using 95% confident interval (CI). RESULTS: Of 14,483 breast cancer screenings in women who had non-fatty breast density, 115 cancers were documented. The mean age of cancer patients was 49.6 years. Of 115 cancers, 105 were evidenced on images (31 with MX alone, 19 with US alone, and 55 with both MX and US). Overall CDR was 7.9 per 1000 examination (95% CI, 6.5-9.5). CDR for MX only (MX-CDR) was 6.5 per 1000 examinations (95% CI, 5.2-7.9). Additional US could significantly improve CDR (P < 0.001; 95% CI, 0.9-2.2); US-ICDR was 1.4 per 1000 examinations. According to age group, the group of 40-59 years had statistically significant improvement of ICDR (P < 0.001). The ICDR was highest in D4 breast density (D4) (US-ICDR = 2.5 per 1000 examinations). CONCLUSION: Use of US adjunct to MX for detection of breast cancer in asymptomatic non-fatty, average-risk women for detection of breast cancer is a promising diagnostic procedure. A significant benefit was documented, in particular, in women aged 40-59 years old, and in women with D4 breast density.

Ultrasonographic characteristics of mammographically occult small breast cancer.

PURPOSE: To analyze significant ultrasonographic findings of small malignant breast mass (≤10 mm) which were occult on mammography. METHODS: The study included 190 small breast masses (≤10 mm), demonstrated on breast ultrasonography, but not mammography. Histopathology (when the masses were biopsied) or serial breast ultrasonography (for at least 24 months) were used to confirm benign or malignant condition of the masses. Univariate and multivariate logistic regression analysis were used to identify significant characteristic malignant findings on ultrasonography. RESULTS: Of 190 masses, 46 were cancer, and 144 were benign. On multivariate analyses, irregular shape (odds ratio [OR], 10.4) and not circumscribed margin (OR, 31.6) were significant features to differentiate between benign and malignant breast masses. However, low width/anteroposterior ratio, echogenic halo, hypoechogenecity and posterior acoustic shadow, which were predictors for malignancy in large breast mass, were not documented in small mass. CONCLUSION: In conclusion, irregular shape and not circumscribed margin detected during ultrasonography were strong predictive signs of malignancy for small malignant breast mass.

Renal artery stenosis: diagnostic performance of balanced fast field gradient echo MRA.

OBJECTIVE: To compare the diagnostic performance of new B-FFE MR angiography with contrast-enhance MR angiography in diagnosis of renal artery stenosis. MATERIAL AND METHOD: One hundred and fourteen patients suspected of having renal artery stenosi underwent MR angiography with 2D B-FFE technique and 3D post contrast enhancement. RESULTS: Compared with contrast enhanced MR angiography, B-FFE MR angiography correctly depicte, significant stenotic renal arteries (> or = 50% stenosis) in 13 and 12 renal arteries from 21 renal arteries reviewed by first and second radiologists, respectively. The overall sensitivity, specificity, negative an, positive predictive values of B-FFE MR angiography in diagnosis of significant renal artery stenosis (> or =50% stenosis) reviewed by first and second radiologists, were 57.1-61.9%, 91.9-93.6%, 96.1-96 4%, and 81.3 92.3%, respectively. CONCLUSION: B-FFE MR angiography of renal arteries can be promising technique for screening patient. who are suspected of having renovascular disease without requirement of intravenous contrast injection especially the kidney disease patients.

Serial MR imaging of small arterially-enhancing liver lesions in patients with chronic liver disease.

OBJECTIVE: To determine the significance of small arterially-enhancing liver lesions seen with magnetic resonance imaging (MRI) in patients with chronic liver disease. MATERIAL AND METHOD: Our institutional review board approved this retrospective study, without requiring informed consent. Over a two-year period, 258 consecutive patients with cirrhosis or chronic hepatitis underwent multiphase three-dimensional, gadolinium-enhanced, breath-hold gradient-echo MRI. From this group, 29 patients underwent at least one follow-up MR study. When a small (< or = 20 mm) arterially-enhancing lesion was detected, the maximum diameter shape, signal intensities (T1-weighted and T2-weighted), and pattern of enhancement were evaluated to assess the associations between the imaging appearance on initial MR exam and subsequent behavior on follow-up imaging. Statistical testing was performed with JMP Statistical Software (SAS, Inc., Cary, NC) and StatXact 7 Statistical Software for Exact Nonparmetric Inference (Cytel, Inc., Cambride, MA). RESULTS: Sixty-five small (< or = 20 mm) arterially-enhancing lesions were detected in 29 patients. Ten of 65 lesions (15%) in nine patients were subsequently proven to represent hepatocellular carcinoma (HCC), while the remaining lesions either disappeared (46) or remained stable in size (9). Of the 10 lesions subsequently proven to represent HCC, eight lesions converted from hypo- or isointense to hyperintense on subsequent T2-weighted MRI (p < 0.001), seven lesions converted from hyper- or isointense to hypointense on subsequent T1-weighted images (p < 0.001), seven lesions demonstrated growth on subsequent MRI exam (mean increase in mean diameter = 1.4 cm), and five lesions subsequently developed rim enhancement that was not initially present. CONCLUSION: Small, arterially-enhancing lesions detected with MRI have a low likelihood of representing HCC, and MRI follow-up of such lesions is a reasonable approach. Lesions that increase in size, convert to hypointense on subsequent T1W images, convert to hyperintense in T2W images, or develop rim enhancement on follow-up MRI images are concerning and should prompt consideration of intervention.