Liver Imaging Reporting and Data System: Discordance Between Computed Tomography and Gadoxetate-Enhanced Magnetic Resonance Imaging for Detection of Hepatocellular Carcinoma Major Features.

PURPOSE: The goal of this study was to compare agreement between computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of the major Liver Imaging Reporting and Data System (LI-RADS) features used in assessment of hepatocellular carcinoma: arterial phase hyperenhancement (APHE), portal venous phase washout (WO), capsule appearance (capsule), and largest diameter (diameter). METHODS: Patients with liver protocol CT and gadoxetate-enhanced MRI within 1 month of each other and at least 1 discrete untreated liver lesion were included. Two readers independently reviewed hepatic arterial phase and portal venous phase of each lesion on both CT and MRI, presented at random. The APHE, WO, capsule, and diameter were assessed for each lesion on CT and MRI. The LI-RADS category was assigned based on the recorded major features. Interobserver agreements between the readers for both imaging modalities and for each of the major features were assessed using κ statistics. Agreement between CT and MRI for each reader and for each feature was assessed using κ statistics. Agreement was interpreted based on κ as follows: 0.20 or less, slight agreement; 0.21 to 0.40, fair agreement; 0.41 to 0.60, moderate agreement; 0.61 to 0.80, substantial agreement; and 0.81 to 1.00, almost perfect agreement. Intraclass correlation coefficient was used to assess concordance of diameter measurements. RESULTS: There were 42 patients (mean age, 62.2 ± 7.0 years; 33 men [78.6%]) with 50 lesions. On CT, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.85), WO (κ = 0.83), and capsule (κ = 0.86). On MRI, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.86) and WO (κ = 0.83) and moderate for capsule (κ = 0.59). Intraclass correlation coefficient for diameter measurement was 0.99 for CT and 0.98 for MRI. For reader 1, the agreement between CT and MRI was fair for APHE (κ = 0.39) and capsule (κ = 0.26) and moderate for WO (κ = 0.49). For reader 2, the agreement between CT and MRI was moderate for APHE (κ = 0.43) and capsule (κ = 0.43) and fair (κ = 0.38) for WO. Agreement between readers for final LI-RADS category was substantial for CT (κ = 0.79) and moderate for MRI (κ = 0.60). Agreement for final LI-RADS categories between MRI and CT was fair for both reader 1 (κ = 0.33) and reader 2 (κ = 0.39). CONCLUSIONS: Interobserver agreement for the major LI-RADS features varies from moderate to almost perfect, for both CT and MRI. However, the agreement between CT and MRI for each of the major LI-RADS features is poor, ranging from fair to moderate. This poor agreement contributes to substantial differences between final LI-RADS category assigned on CT versus MRI.

Diagnosis of acute cholecystitis: why do patients get multiple studies?

The aim of this study is to establish factors affecting total number of imaging studies performed for acute cholecystitis (AC) prior to surgery. The study included subjects with cholecystectomy and pathologic diagnosis of AC 1/1/05-1/1/14 and imaging studies (computed tomography (CT), ultrasound (US), and/or cholescintigraphy) within 7 days of surgery. The subjects were separated into groups based on modality of the first study. For each subject, report of the first study was reviewed for report's confidence in diagnosis of AC (scored 1-5 on Likert scale: 5 = definitely AC, 1 = definitely no AC), recommendation of additional study, clinical history concerning for AC (history of right upper quadrant pain, cholelithiasis, and/or "rule out AC"). There were 219, 339, and 38 subjects in CT, US, and cholescintigraphy groups, respectively, with mean confidence scores of 3.7 (± 1.2), 3.7 (± 1.1), and 4.7 (± 0.9), respectively (p < 0.001). Prior to surgery, only one study was performed in 21.9 % (48/219) of CT group, 70.2 % (238/339) of US group, and 71.1 % (27/38) of cholescintigraphy group (p < 0.0001). Compared to the US group, the odds of undergoing additional study were 11.8 times higher (p < 0.001) in CT group and 1.7 times higher (p = 0.229) in cholescintigraphy group, adjusting for age, sex, time interval between first study and the surgery, confidence score, recommendation of follow-up study, and clinical history concerning for AC. Patients with AC and CT as the first study are more likely to undergo additional imaging studies prior to surgery as compared to US or cholescintigraphy.

Incidental pancreatic cystic lesions: is there a relationship with the development of pancreatic adenocarcinoma and all-cause mortality?

PURPOSE: To establish the effect of incidental pancreatic cysts found by using computed tomographic (CT) and magnetic resonance (MR) imaging on the incidence of pancreatic ductal adenocarcinoma and overall mortality in patients from an inner-city urban U.S. tertiary care medical center. MATERIALS AND METHODS: Institutional review board granted approval for the study and waived the informed consent requirement. The study population comprised cyst and no-cyst cohorts drawn from all adults who underwent abdominal CT and/or MR November 1, 2001, to November 1, 2011. Cyst cohort included patients whose CT or MR imaging showed incidental pancreatic cysts; no-cyst cohort was three-to-one frequency matched by age decade, imaging modality, and year of initial study from the pool without reported incidental pancreatic cysts. Patients with pancreatic cancer diagnosed within 5 years before initial CT or MR were excluded. Demographics, study location (outpatient, inpatient, or emergency department), dates of pancreatic adenocarcinoma and death, and modified Charlson scores within 3 months before initial CT or MR examination were extracted from the hospital database. Cox hazard models were constructed; incident pancreatic adenocarcinoma and mortality were outcome events. Adenocarcinomas diagnosed 6 months or longer after initial CT or MR examination were considered incident. RESULTS: There were 2034 patients in cyst cohort (1326 women [65.2%]) and 6018 in no-cyst cohort (3,563 [59.2%] women); respective mean ages were 69.9 years ± 15.1(standard deviation) and 69.3 years ± 15.2, respectively (P = .129). The relationship between mortality and incidental pancreatic cysts varied by age: hazard ratios were 1.40 (95% confidence interval [ CI confidence interval ]: 1.13, 1.73) for patients younger than 65 years and 0.97 (95% CI confidence interval : 0.88, 1.07), adjusted for sex, race, imaging modality, study location, and modified Charlson scores. Incidental pancreatic cysts had a hazard ratio of 3.0 (95% CI confidence interval : 1.32, 6.89) for adenocarcinoma, adjusted for age, sex, and race. CONCLUSION: Incidental pancreatic cysts found by using CT or MR imaging are associated with increased mortality for patients younger than 65 years and an overall increased risk of pancreatic adenocarcinoma.

T1-hyperintense renal lesions: can high signal predict lack of enhancement?

OBJECTIVE: To establish highly specific criteria for predicting non-enhancement in T1-hyperintense non-fat-containing (T1-high) renal lesions using unenhanced fat-suppressed T1-weighted (T1-FS) images. MATERIALS AND METHODS: This IRB-approved, HIPAA-compliant, retrospective study included T1-high renal lesions found between 7/1/2012 and 7/1/2014. The largest lesion diameter and heterogeneity, mean signal intensity of lesion, and adjacent renal cortex were recorded from T1-FS images. The presence/absence of lesion enhancement was determined from subtraction images. T1 signal ratio (T1-SR) was calculated as (mean SI of lesion)/(mean SI of cortex). Logistic regression with binary outcome of the presence or absence of lesion enhancement was performed. Cut-off T1-SR to maximize specificity was established from receiver operator curve analysis. RESULTS: There were 101 patients (58 [57.4%] male) with non-enhancing lesions and 80 patients (51 [63.8%] male) with enhancing lesions, mean ages 64.0 ± 13.3 and 62.1 ± 13.8 years, respectively. Median sizes were 11 mm (IQR 8-16) and 20.5 mm (IQR 15-29) for non-enhancing and enhancing lesions, respectively (p < 0.0001). 19/101 (18.8%) of non-enhancing and 56/80 (70.0%) of enhancing lesions were heterogeneous (p < 0.0001). T1-SR was 1.77 ± 0.6 and 1.25 ± 0.42 for non-enhancing and enhancing lesions, respectively (p < 0.0001). For each increase of 0.5 in T1-SR, odds ratio for non-enhancement was 3.3 (95% CI 1.85-5.79), adjusted for lesion size and heterogeneity. T1-SR alone had area under the curve of 0.88 (95% CI 0.78-10.89) for non-enhancement. T1-SR ≥ 2.15 had positive likelihood ratio of 9.5 for non-enhancement. CONCLUSION: Signal ratio of lesion to cortex ≥ 2.15 on unenhanced T1-weighted images is a highly specific predictor for non-enhancement.

Traumatic and non-traumatic adrenal emergencies.

Multiple traumatic and non-traumatic adrenal emergencies are occasionally encountered during the cross-sectional imaging of emergency department patients. Traumatic adrenal hematomas are markers of severe polytrauma, and can be easily overlooked due to multiple concomitant injuries. Patients with non-traumatic adrenal emergencies usually present to an emergency department with a non-specific clinical picture. The detection and management of adrenal emergencies is based on cross-sectional imaging. Adrenal hemorrhage, adrenal infection, or rupture of adrenal neoplasm require immediate detection to avoid dire consequences. More often however, adrenal emergencies are detected incidentally in patients being investigated for non-specific acute abdominal pain. A high index of suspicion is required for the establishment of timely diagnosis and to avert potentially life-threatening complications. We describe cross-sectional imaging findings in patients with traumatic and non-traumatic adrenal hemorrhage, adrenal infarctions, adrenal infections, and complications of adrenal masses.

Beyond ultrasound: CT and MRI of ectopic pregnancy.

OBJECTIVE: Although ultrasound is the primary modality used in the diagnosis of ectopic pregnancy, various forms of this condition and their complications may occasionally be further evaluated with MRI or may be incidentally detected on CT or MRI when an alternative diagnosis is suspected. CONCLUSION: Various types of ectopic pregnancy have characteristic imaging features. Radiologists should be familiar with these features and should always consider the possibility of ectopic pregnancy in the setting of hemoperitoneum or a pelvic mass in a woman of child-bearing age. Familiarity with the typical CT and MRI appearances of various forms of ectopic pregnancy facilitates prompt and accurate diagnosis and treatment.

MR imaging of renal collecting system with gadoxetate disodium: feasibility for MR urography.

PURPOSE: To determine the feasibility of using gadoxetate disodium for MR urography. MATERIALS AND METHODS: We retrospectively reviewed 50 consecutive gadoxetate disodium-enhanced abdominal MRI examinations meeting inclusion criteria. For each examination, 30 min postcontrast hepatobiliary phase sequences were reviewed to assess bilateral collecting system segments, including upper pole, interpolar, and lower pole calyces; renal pelvis; and proximal one-third of ureter. Each segment was assessed for degree of opacification (none, <50%, ≥50%, complete) and susceptibility artifact (none, partial thin rim, thick/complete rim, total obscuration). Opacification and susceptibility scores were also calculated for each examination. RESULTS: The 50 reviewed examinations were performed on 46 patients (26 women, 20 men; mean age, 57 years) and included a total of 1000 segments. Of these, 808 (80.8%) were opacified completely, 103 (10.3%) were opacified ≥50%, 39 (3.9%) were opacified <50%, and 50 (5.0%) were not opacified. Of 1000 segments, no susceptibility artifact was present in 822 (82.2%), while a partial thin rim was present in 113 (11.3%), a thick/complete rim in 64 (6.4%) and total obscuration in 1 (0.1%). CONCLUSION: Gadoxetate disodium contrast produced a high degree of opacification of the proximal urinary collecting system with low incidence of susceptibility artifact; therefore, it is a feasible contrast agent for MR urography.

Hepatic enhancement during the hepatobiliary phase after gadoxetate disodium administration in patients with chronic liver disease: the role of laboratory factors.

PURPOSE: To identify factors influencing hepatobiliary phase (HBP) hepatic enhancement on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD). MATERIALS AND METHODS: We retrospectively reviewed abdominal gadoxetate disodium-enhanced MRIs and medical records of patients with (n=97) and without (n=48) CLD. CLD subgroups were formed based on normal/abnormal components of liver function tests (LFTs). Hepatic enhancement coefficients (HEKs) were calculated on MRI, and compared with LFTs and Model for End-stage Liver Disease (MELD) scores. RESULTS: The mean HEK was significantly lower (P<0.0008) in the CLD than control group. The mean HEK was similar to controls in the subgroup with all normal LFTs (P=0.09) and subgroup with normal direct bilirubin (DB) (p=0.09), while it was significantly reduced (P<0.0001) in the subgroup with elevated DB. For all other LFT components, regardless of normal or abnormal values, there was a significant reduction in the mean HEKs versus controls (all P values<0.01). There was a highly negative correlation between the mean HEKs in CLD subgroups and number of abnormal LFTs (r=-0.93) and MELD scores (r=-0.89). CONCLUSION: HBP hepatic enhancement in CLD patients is similar to those with no CLD as long as direct bilirubin remains normal. Higher MELD scores and higher number of abnormal LFT components are associated with reduced hepatic enhancement.

Findings of cecal volvulus at CT.

PURPOSE: To assess the diagnostic performance of computed tomographic (CT) and radiographic (as seen on CT topograms) signs of cecal volvulus. MATERIALS AND METHODS: In this institutional review board-approved, HIPAA-compliant retrospective study, the CT and CT topogram findings in 11 patients (one man, 10 women; age range, 26-100 years) with surgically confirmed cecal volvulus and 12 control patients were reviewed. The control subjects had suspicious radiographs, had undergone CT within 24 hours of radiography, and had received a clinical diagnosis other than cecal volvulus. Three radiologists independently evaluated the CT topograms for cecal distention, the coffee bean sign, cecal apex location, and distal colon decompression. CT images were analyzed for cecal distention, cecal apex location, distal colon decompression, and presence or absence of the whirl, ileocecal twist, transition point(s), the X-marks-the-spot, and the split wall. Sensitivity, specificity, and predictive values were computed. Baseline statistical values for the cecal volvulus and control groups were analyzed by using a two-tailed Z test to compare proportions with a threshold confidence interval of 95%. CT findings of bowel ischemia (free air or fluid, pneumatosis intestinalis, portal venous gas, mesenteric stranding) were correlated with pathology report findings. RESULTS: On CT topograms, greater than 10-cm cecal distention, coffee bean sign, and left upper quadrant cecal apex had sensitivities of 45% (five of 11 patients), 27% (three of 11 patients), and 45% (five of 11 patients), respectively, and specificities of 100% (12 of 12 control subjects), 92% (11 of 12 control subjects), and 100% (12 of 12 control subjects), respectively. Distal colon decompression had sensitivities and specificities of 91% (10 of 11 patients) and 83% (10 of 12 control subject), respectively, on topograms and of 91% (10 of 11 patients) and 92% (11 of 12 patients), respectively, on CT images. On cross-sectional CT images, greater than 10-cm cecal distention, left upper quadrant cecal apex, whirl, ileocecal twist, transition point(s), X-marks-the-spot, and split wall had sensitivities of 45% (five of 11 patients), 36% (four of 11 patients), 73% (eight of 11 patients), 54% (six of 11 patients), 82% (nine of 11 patients), 27% (three of 11 patients), and 54% (six of 11 patients), respectively; each had 100% specificity. Pneumatosis intestinalis and free air had 100% (four of four control subjects) specificity. Overall, CT signs of bowel ischemia correlated poorly with pathology report findings. CONCLUSION: When cecal volvulus is suspected, the absence of distal colonic decompression on CT topograms makes the diagnosis very unlikely. Whirl, ileocecal twist, transition points, X-marks-the-spot, and split wall have high specificity for cecal volvulus.

CT findings of sigmoid volvulus.

OBJECTIVE: The purpose of this study was to evaluate the features of sigmoid volvulus on CT scanograms and cross-sectional images. MATERIALS AND METHODS: We retrospectively reviewed 21 cases of sigmoid volvulus in 15 men and six women. Three radiologists evaluated scanograms and cross-sectional images for several classic and two novel imaging signs of volvulus: crossing sigmoid transitions (called the X-marks-the-spot sign) and folding of the sigmoid wall by partial twisting (called the split-wall sign). A general impression was assigned to scanograms and cross-sectional images. CT findings suggesting bowel compromise were compared with pathologic and endoscopic findings. RESULTS: The most sensitive scanogram findings were absence of rectal gas (19 of 21 cases, 90%) and an inverted-U-shaped distended sigmoid (18 of 21 cases, 86%) followed by the coffee bean sign and disproportionate sigmoid enlargement (both 16 of 21 cases, 76%). The most sensitive cross-sectional findings were one sigmoid colon transition point (20 of 21 cases, 95%) and disproportionate enlargement of the sigmoid (18 of 21 cases, 86%). The X-marks-the-spot and split-wall signs were present in nine of 21 (43%) and 11 of 21 (52%) patients, but one of the two signs was present in 18 of 21 patients (86%). Classic radiographic and definitive cross-sectional findings were seen in 11 of 21 (52%) and 16 of 21 (76%) patients. CT findings were definitive in five of seven patients (71%) with indeterminate scanogram findings. Imaging signs suggesting bowel compromise correlated poorly with clinical ischemia, but CT features were present in all three patients with frank necrosis. CONCLUSION: Sigmoid volvulus has a spectrum of imaging findings. A classic appearance is absent on approximately one half of scanograms and one fourth of CT scans. Use of new signs that model the pathophysiologic characteristics of volvulus (X-marks-the-spot sign for more complete twisting and split-wall sign for less severe twisting) may improve diagnostic confidence.

Can lab data be used to reduce abdominal computed tomography (CT) usage in young adults presenting to the emergency department with nontraumatic abdominal pain?

We sought to determine whether laboratory parameters could be found, predictive of a negative abdominal CT scan in young adults with nontraumatic abdominal pain. Following institutional review board approval, we evaluated CT reports of 522 patients, aged 21-35 years old, who presented to the Emergency Department with nontraumatic abdominal pain. Bivariate analyses relating ten laboratory parameters to whether the CT detected a cause for abdominal pain were conducted. A multivariate logistic regression model was then derived, with all variables in the final model significant at p < 0.05. Variables were dichotomized to yield odds ratios and 95% confidence intervals. Of the 522 patients meeting inclusion criteria, 45% had a cause for pain demonstrated by CT. Predictors of a negative CT in men were normal hematocrit and negative urine blood (p = 0.045, p = 0.016, respectively), and in women normal hematocrit, granulocyte percent, and alkaline phosphatase (p = 0.023, p = 0.039, p < 0.0001, respectively). When standard normal values were used to calculate descriptive statistics, only granulocyte percent in women had a significant confidence interval (odds ratio 2.5, confidence interval 1.6-4.0). Among the 208 women with normal granulocyte percent, the final clinical diagnosis was appendicitis, cholecystitis, and diverticulitis, in three, three, and two cases, respectively (4% combined). In summary, no laboratory test was sufficient to offer reassurance that a CT is not necessary in a young adult patient with nontraumatic abdominal pain. Alternative strategies should be considered to decrease the use of CT, and its associated radiation exposure, in young adults with nontraumatic abdominal pain.

Breast reconstruction with deep inferior epigastric artery perforator flap: 3.0-T gadolinium-enhanced MR imaging for preoperative localization of abdominal wall perforators.

PURPOSE: To prospectively evaluate 3.0-T gadolinium-enhanced magnetic resonance (MR) imaging for localization of inferior epigastric artery (IEA) perforators before reconstructive breast surgery involving a deep inferior epigastric perforator (DIEP) flap. MATERIALS AND METHODS: This study was exempt from institutional review board approval, and the requirement for informed patient consent was waived. Data were collected and stored in compliance with HIPAA regulations. Nineteen patients (mean age, 46.3 years) underwent three-dimensional gadolinium-enhanced 3.0-T MR imaging of the abdomen before undergoing DIEP flap breast reconstruction. Up to four of the largest perforators arising from the IEA on each side of the umbilicus were identified. The diameter, intramuscular course, and distance from the umbilicus of each perforator were recorded. One of the marked perforators on each side was labeled "the best" on the basis of an optimal combination of perforator features: diameter, intramuscular course, and location with respect to the flap edges. MR findings were compared with intraoperative findings. The two-tailed Student t test was used to compare the mean diameters of all perforators with the mean diameters of the perforators labeled as the best. RESULTS: There were 30 surgical flaps, and 11 (58%) of the 19 patients underwent bilateral flap dissection. At surgery, 122 perforators were localized, and 118 (97%) of these perforators-with a mean diameter of 1.1 mm (range, 0.8-1.6 mm)-had been identified at preoperative MR imaging. Thirty perforators with a mean diameter of 1.4 mm (range, 1.0-1.6 mm) were labeled as the best at MR imaging. Thirty-three perforators were harvested intraoperatively, and all of these had been localized preoperatively. Twenty-eight (85%) of these 33 perforators were labeled as the best at MR imaging. CONCLUSION: Gadolinium-enhanced 3.0-T MR imaging can be used to accurately localize IEA perforators and to select the optimal perforator to be harvested for DIEP flap reconstructive breast surgery.

CT features of adnexal involvement in patients with diverticulitis.

OBJECTIVE: The purpose of this study was to evaluate the CT findings in patients with colosalpingeal fistula complicating diverticulitis. MATERIALS AND METHODS: Using a medical records database and radiology information system, we identified the cases of 14 women who underwent colonic resection for diverticulitis and simultaneous salpingo-oophorectomy with or without hysterectomy over a 10-year period. The patients were separated into two groups: group 1 included women with a pathologically proven colosalpingeal fistula, and group 2 included those who had contiguous periadnexal inflammation without a fistula. Preoperative CT scans of these patients were retrospectively evaluated in consensus by two radiologists blinded to the pathologic findings. The presence of adnexal gas and fluid collections was recorded. The findings were compared with those in the operative and pathology reports. RESULTS: Among 14 patients who had sigmoid (n = 13) or cecal (n = 1) diverticulitis, eight patients were in group 1 and six were in group 2. On CT scans, an adnexal collection of gas, either alone or in combination with fluid, was found in seven patients (88%) in group 1 and in no patients in group 2, resulting in 88% sensitivity and 100% specificity in the detection of colosalpingeal fistula. An adnexal collection of fluid alone was found in one patient (13%) in group 1 and one patient (17%) in group 2, resulting in sensitivity and specificity of 13% and 83%. CONCLUSION: In patients with diverticulitis, a collection of gas, either alone or in combination with fluid, within the adnexum is a sensitive and specific predictor of the presence of a fistula between the colon and an adnexum.

Small bowel obstruction due to an impacted endoscopy capsule.

Capsule endoscopy (CE), a recently introduced technology, offers important benefits for evaluation of small bowel pathology as compared to traditional radiologic and endoscopic studies. The most striking complication of this modality is capsule retention, which may obligate invasive retrieval. The radiologist should be aware of the natural course, presentation, diagnostic evaluation, and treatment options for this retained foreign body.

Transient arterial phase respiratory motion-related artifact in MR imaging of the liver: an analysis of four different gadolinium-based contrast agents.

PURPOSE: The purpose was to compare hepatic arterial phase (HAP) respiratory motion artifact (RMA) between gadoxetate, gadobutrol, gadopentetate, and gadobenate. MATERIALS/METHODS: Two hundred cases of each gadolinium agent were included. RMA was assigned using 5-point Likert scale (1=no motion, 5=extreme motion) on precontrast and HAP. RMA increase (increase ≥1 on HAP from precontrast) was the outcome in logistic regression. RESULTS: Odds of RMA increase for gadoxetate were 5.5 (P<.001), 3.6 (P=.034), and 9.5 (P<.001) times higher than gadobutrol, gadopentetate, and gadobenate, respectively. Gadolinium volume and dose were not independent predictors of RMA increase. CONCLUSION: Gadoxetate has increased odds of RMA compared with other gadolinium agents; tight contrast bolus is not a contributor.

Patients 65 years and older with incidental pancreatic cysts: Is there a relationship between all-cause mortality and imaging follow-up?

PURPOSE: To assess the relationship between imaging follow-up and all-cause mortality in subjects ≥65 years with and without incidental pancreatic cysts (IPC). METHODS AND MATERIALS: Patients ≥65 years with abdominal CT/MR 11/1/01-11/1/11 were included. IPC group included subjects with IPC on CT/MR report; No-IPC group was 3:1 frequency-matched on age decade, imaging modality and year of initial study from the pool without reported IPC. Demographics, date of last encounter, date of death, Charlson scores within 3 months before initial CT/MR and number of abdominal CTs and MRs performed after initial study were recorded. Logistic regression models with binary outcomes of death and having post-index imaging were constructed. Models were adjusted for age, race, sex, Charlson score and follow-up time. Subgroups were created based on interactions between variables. RESULTS: There were 1320 subjects in IPC group and 3805 in No-IPC group, with mean ages 79.1 (±8.0) and 78.8 (±8.0) years, respectively (p=0.293), and median follow-up times of 3.1 (IQR 0.74-5.26) and 3.0 (0.36-5.23) years, respectively (p=0.009). Adjusted odds ratios of post-index imaging for IPC were 2.18 (p<0.001) in subgroup<84years and follow-up <4years, 3.37 (p<0.001) in subgroup <84 years and follow-up ≥4 years, and 1.20 (p=0.201) in subgroup ≥84 years. Number of follow-up CTs and MRs was not independently associated with decreased odds of death in any subgroup. CONCLUSION: Older subjects with IPC are more likely to undergo imaging follow-up compared to subjects without IPC, yet increasing number of follow-up studies does not decrease the odds of death.

Pancreatic cysts: What imaging characteristics are associated with development of pancreatic ductal adenocarcinoma?

PURPOSE: To assess relationship between pancreatic cysts (PC) and pancreatic ductal adenocarcinoma (PDAC) and to compare imaging features of PC in subjects who develop PDAC and those who do not. MATERIAL AND METHODS: This case-control IRB-approved HIPAA-compliant study included patients with PDAC (cases) and lung cancer (controls), diagnosed between 1/1/05-1/1/14. The most recent abdominal CT/MR of each patient done >6months prior to cancer diagnosis date was reviewed by radiologist blinded to case/control status. Presence of PC, number and size of largest PC, presence of main pancreatic duct (MPD) dilatation (MPD >3mm) were recorded. Simple PC was defined as lack of calcifications, septations and enhancement. Logistic regression models with binary outcome of PDAC were constructed. RESULTS: There were 88 cases and 273 controls with mean ages of 69.6 years (±10.3) and 69.8 years (±12.0), respectively (p=0.864). PC were present in 21.6% (19/88) cases and in 9.2% (25/273) controls (p=0.002). The OR of PC for development of PDAC was 2.83, adjusting for age, sex and race (p=0.001). Mean PC size was 14.8mm (±8.7) in cases and 7.6mm (±8.0) in controls (p=0.007). PC were solitary in 6 (31.6%) of 19 cases and 21 (84.0%) of 25 controls (p=0.001). There was no significant difference in proportions of simple cysts or MPD dilatation between cases and controls. Multiple PC had 8.2 times increased odds of PDAC compared with solitary PC, adjusting for cyst size (p=0.007). CONCLUSION: Multiple PC are associated with 8.2 times higher odds of PDAC compared with solitary PC.

Improving diagnosis of atraumatic splenic lesions, Part III: malignant lesions.

Focal atraumatic splenic lesions often pose a diagnostic challenge on cross-sectional imaging. They can be categorized based on etiology, as nonneoplastic, benign neoplastic, and malignant neoplastic (discussed in Part III) lesions, or on prevalence, as common, uncommon, and rare lesions. Familiarity with pertinent clinical parameters, etiology, pathology, prevalence, and ancillary features such as splenomegaly, concomitant hepatic involvement, and extrasplenic findings, in addition to knowledge of imaging spectra of the lesions, can improve diagnostic confidence. Consideration of these factors together can arm the radiologist with the necessary tools to render a more confident diagnosis and thus better aid management.