Intravoxel Incoherent Motion of Colon Cancer Liver Metastases for the Assessment of Response to Antiangiogenic Treatment: Results from a Pilot Study.

OBJECTIVE: This study was aimed at evaluating the intravoxel incoherent motion (IVIM) parameter alterations of liver metastases of colorectal carcinoma (CRC) during antiangiogenic bevacizumab combination therapy. METHODS: Twenty-five patients with CRC liver metastases treated with bevacizumab in combination with FOLFOX-or-FOLFIRI protocols were enrolled in the study. MRI was performed using a 1.5-tesla scanner pre-treatment (PT) and at 3, 6, and 9 months of therapy. Routine abdominal MRI sequences and an IVIM-DWI (diffusion-weighted imaging) sequence were obtained. The IVIM-DWI sequence was executed with 16 b-values varying from 0 to 1,400 s/mm2. The mean values of apparent diffusion coefficient (ADC), true diffusion (D), pseudodiffusion (D*), and perfusion fraction (f) of each metastasis were obtained for all b-values, and the time-related changes were recorded to analyze the chronologic responses to antiangiogenic therapy. The RECIST 1.1 criteria were used for the evaluation of treatment response. RESULTS: The diameters of the metastases diminished significantly at 9 months when compared with PT (p = 0.03). The D (p = 0.10) and ADC (p = 0.21) values of the metastases increased at 9 months of therapy. D* was the highest at 3 months (p =0.24); it decreased at 6 (p =0.97) and 9 months (p =0.87) of therapy. The f value had peaked at 3 months (p =0.51) and started to decrease thereafter. At 6 months, f decreased to the lowest values (p =0.12). CONCLUSION: IVIM parameters, particularly the perfusion fraction, may quantitatively reflect the response to antiangiogenic treatment. The antiangiogenic response manifests after 3 months of therapy before the RECIST-related response.

High-resolution computed tomography and rheumatoid arthritis: semi-quantitative evaluation of lung damage and its correlation with clinical and functional abnormalities.

BACKGROUND: We aimed to establish risk factors for radiological lung damage associated with rheumatoid arthritis (RA) and determine whether clinical findings and pulmonary function test were correlated with Warrick score calculated on the basis of high-resolution computed tomography or not. METHODS: One hundred thirty RA patients who were followed at rheumatology outpatient clinic were included through retrospective screening. To evaluate radiological involvement, the semi-quantitative evaluation proposed by Warrick was used to assign a score for each lesion based on the severity and extent of the pulmonary damage. In addition to the total score, indices for alveolitis and fibrosis were created. The correlations between each score and clinical and functional parameters were tested for all patients. RESULTS: We showed that age was an independent explanatory variable of radiological lung damage. Percentage of predicted lung diffusion capacity for carbon monoxide (DLco) below 75 % and presence of respiratory symptoms were found to contribute more to radiological lung damage. Warrick score was positively correlated with age at study onset (r = 0.43, p < 0.001). In addition, a negative correlation was found between Warrick score and DLco % predicted (r = -0.357, p = 0.001). Alveolitis index was negatively correlated with DLco % predicted (r = -0.321, p = 0.003). CONCLUSIONS: It is considered that this semi-quantitative method may have added value in early diagnosis, appropriate treatment decisions and follow-up when taken into account together with risk factors associated with pulmonary damage in RA.

Major depressive disorder in chronic heart failure patients: Does silent cerebral infarction cause major depressive disorder in this patient population?

OBJECTIVE: Depression frequently occurs in patients with heart failure as similar pathophysiological mechanisms present in both these diseases. Patients with dilated cardiomyopathy (DCM) have a high incidence of clinically asymptomatic silent cerebral infarction (SCI). This study aimed to evaluate the relation between SCI and major depressive disorder (MDD), and between MDD and clinical and biochemical parameters in DCM patients. METHODS: Patients with ischemic and non-ischemic DCM who had chronic heart failure (CHF) (39 male, 10 female, age 60±10 years) were included in the study. Mean patient ejection fraction (EF) was 34±10%. Patients had no localized neurological symptoms or stroke history. The etiology of DCM was ischemic in 40 and non-ischemic in 9 patients. Twenty-five age-matched healthy volunteers served as a control group for comparison of SCI and MDD prevalence. RESULTS: Patients had mild to severe CHF symptoms. Prevalence of SCI and MDD was significantly higher in patients with DCM than in the control group; 63% vs 8%; p<0.001, and 52% vs 20%; p<0.001 respectively. Patients with SCI had a higher prevalence of MDD than patients without SCI in DCM (61% vs 27%, p=0.02). CONCLUSION: CHF patients have an increased prevalence of SCI and MDD. Patients with SCI have a higher prevalence of MDD compared to patients without SCI in CHF.

18 F-FDG PET/MRI of Primary Hepatic Malignancies: Differential Diagnosis and Histologic Grading

BACKGROUND: Distinguishing between IHCC and HCC is important because of their differences in treatment and prognosis. The hybrid Positron Emission Tomography/magnetic Resonance Imaging (PET/MRI) system has become more widely accessible, with oncological imaging becoming one of its most promising applications. OBJECTIVE: The objective of this study was to see how well 18F-fluorodeoxyglucose (18F-FDG) PET/MRI could be used for differential diagnosis and histologic grading of primary hepatic malignancies. METHODS: We retrospectively evaluated 64 patients (53 patients with HCC, 11 patients with IHCC) with histologically proven primary hepatic malignancies using 18F-FDG/MRI. The Apparent Diffusion Coefficient (ADC), Coefficient of Variance (CV) of the ADC, and standardized uptake value (SUV) were calculated. RESULTS: The mean SUVmax value was higher for IHCC (7.7 ± 3.4) than for HCC (5.2 ± 3.1) (p = 0.019). The area under the curve (AUC) was 0.737, an optimal 6.98 cut-off value providing 72% sensitivity and 79% specificity. The ADCcv value in IHCC was statistically significantly higher than in HCC (p=0.014). ADC mean values in HCCs were significantly higher in low-grade tumors than in high-grade tumors. The AUC value was 0.73, and the optimal cut-off point was 1.20x10-6 mm2/s, giving 62% sensitivity and 72% specificity. The SUVmax value was also found to be statistically significantly higher in the high-grade group. The ADCcv value in the HCC low-grade group was found to be lower than in the highgrade group (p=0.036). CONCLUSION: 18F FDG PET/MRI is a novel imaging technique that can aid in the differentiation of primary hepatic neoplasms as well as tumor-grade estimation.

Preoperative evaluation of myometrial invasion in endometrial carcinoma: diagnostic performance of 3T MRI.

PURPOSE: To evaluate the diagnostic accuracy of 3T MRI in preoperative staging of myometrial invasion. METHODS: Twenty-eight women with histological diagnosis of endometrial carcinoma were included in this prospective study. After T2-W SS-TSE and DWI, dynamic series of T1-W THRIVE images were obtained (0-180 s) followed by a T1-W THRIVE sequence in the late phase (5th min). For detection of deep myometrial infiltration: sensitivity, specificity, PPV, NPV, and accuracy were calculated on T2-W, postcontrast early arterial and late phase T1-W, and DWI. For the quantitative analysis of DWI, ADC values of the tumor were calculated and correlated with histologic grade. For the quantitative evaluation of dynamic series, SI-time curves were obtained and the maximum relative enhancement, wash-in rate, time-to-peak, and wash-out rate of masses and myometrium were compared. RESULTS: T2-W and early phase contrast-enhanced sequences obtained sensitivity 100 %, specificity 76 %, PPV 58 %, NPV 100 %, and accuracy 82 %; late-phase contrast-enhanced images obtained sensitivity 100 %, specificity 81 %, PPV 64 %, NPV 100 %, and accuracy 86 %; DWI obtained lower accuracy [sensitivity 71 %, specificity 62 %, PPV 38 %, NPV 87 %, and accuary 57 %] than T2-W and postcontrast images. The MRE of carcinomas were significantly lower than those of the myometrium. This analysis showed a significant improvement in tumor versus myometrium contrast during the late phase. On DWI, the mean ADC value of tumor was 1.02 ± 0.48 × 10(-3). There was no statistically significant correlation between tumor grades and ADCs. CONCLUSIONS: As the 3T MRI scanner allows high-resolution images, accurate assessment of myometrial infiltration can be done especially with postcontrast late phase images.

Malignant versus benign mediastinal lesions: quantitative assessment with diffusion weighted MR imaging.

OBJECTIVES: We aimed to evaluate the performance of diffusion-weighted magnetic resonance imaging in differentiating malignant from benign mediastinal lesions. METHODS: Fifty-three mediastinal lesions were examined with T1- and T2-weighted (W) conventional images. Then, two diffusion-weighted images were obtained with b = 0 and 1000 s/mm² values and apparent diffusion coefficients (ADC) were calculated. The statistical significance of differences between measurements was tested using the Student-t test. RESULTS: The mean ADC of malignant lesions was significantly lower than that of the benign masses (p < 0.001). The cut-off value of ≤ 1.39 × 10(-3) mm²/s indicated a malignant lesion with a sensitivity of 95% and specificity of 87%. CONCLUSION: Diffusion-weighted imaging may be helpful in differentiating benign from malignant mediastinal masses.

The comparison of pancreatic and hepatic steatosis in healthy liver donor candidates.

The aim of this study was to investigate the relationship between nonalcoholic fatty liver disease (NAFLD) and pancreatic steatosis (PS) in patients with biopsy-proven NAFLD. 228 patients with biopsy-proven NAFLD patients who admitted to the Faculty of Medicine of Demiroglu Bilim University between 2004 and 2019 were included in the study. Demographic, laboratory, histological and radiological findings of the patients were recorded retrospectively. Hepatosteatosis (HS) levels were measured by both CT and biopsy, while PS levels were measured by 3 different CT-based techniques. 89 (39%) of the patients were female and 139 (61%) were male. The mean body mass index (BMI) was 27.2 ± 4.0. Biochemical parameters were within normal limits. Liver biopsy showed a significant correlation with HS grade on CT scan (p < 0.001). When CT findings were compared, a significant correlation was found between PS and HS (p < 0.05), but there was no correlation between the HS level in biopsy and the pancreatic adiposity on CT (p > 0.05). Our study was the first to compare biopsy-proven NAFLD and PS, and no correlation was found between biopsy-proven NAFLD and PS.

Hepatic adenomatosis in a 7-year-old child treated earlier with a Fontan procedure.

Patients who undergo a Fontan procedure experience some degree of liver disease. Hemodynamic changes such as central venous hypertension, depressed dynamic cardiac output, and late ventricular dysfunction combined with long-standing hypoxia preceding the Fontan procedure all are recognized risk factors for hepatic injury. The histopathologic changes associated with cardiac hepatopathy include chronic passive congestion, centrilobular necrosis, and cardiac cirrhosis. However, hepatic adenoma and hepatic adenomatosis (HA) are not well-known pathologies during the course of cardiac hepatopathy. This study focused on a 7-year-old girl with chronic hepatic changes and HA who had undergone a Fontan procedure. Hepatic adenomatosis was diagnosed on the basis of magnetic resonance imaging (MRI) and MRI-guided liver biopsy. To the best of the authors' knowledge, this case involved the youngest patient with hepatocellular adenomatosis documented in the literature. It was a unique case because the patient experienced HA after a Fontan procedure.

Diffusion weighted MR imaging in the differential diagnosis of haemangiomas and metastases of the liver.

BACKGROUND: The purpose of the study was to evaluate the value of diffusion-weighted imaging in the differential diagnosis of haemangiomas from metastases of the liver. PATIENTS AND METHODS.: We analyzed 69 lesions in 38 patients (33 haemangiomas; 36 metastases) in the retrospective study. Diffusion-weighted imaging was performed using a breath-hold single-shot echo-planar spin echo sequence with three b factors (0, 500 and 1000 sec/mm(2)), and apparent diffusion coefficients (ADCs) were calculated. For the quantitative evaluation, signal intensity of the lesions, lesion-to-liver signal intensity ratios, ADC of the lesions, and lesion-to-liver ADC ratios were compared between the groups. The statistical significance was determined by student's-t test. RESULTS: With the b factor 500 sec/mm(2), no statistical significance was achieved (p>0.05). With the b factor of 1000 sec/mm(2), both the signal intensity and lesion-to-liver signal intensity ratio of the metastases were significantly higher than those for haemangiomas (p<0.001). The cut-off value at 2.6 yielded a sensitivity of 86% and a specificity of 82% for the lesion-to-liver signal intensity ratio. The ADC, and lesion-to-liver ADC ratio of the metastases were significantly lower than those of haemangiomas (p<0.001). With cut-off value of 1.7, ADC ratio had a sensitivity of 88% and a specificity of 72% for ADC lesion/liver. CONCLUSIONS: Diffusion-weighted imaging with high b value may help in the differential diagnosis of metastases from haemangiomas of the liver.

A case of Jarcho-Levin syndrome associated with bilateral cystic renal disease and wilms tumor: MR imaging findings.

Jarcho-Levin syndrome (JLS) is a congenital disorder characterized by a variety of vertebral and costal anomalies that result in thoracic deformity. Hitherto, a plethora of associated anomalies have been described in several reports. In this report, the authors describe a case of JLS who has Wilms tumor and bilateral cystic renal disease. To the authors' knowledge, there is only a single case of JLS who presented with multiple renal cortical cysts, but none with an associated Wilms tumor in the literature. Additional anomalies seen in the present case that are related with this syndrome are also discussed.

A case report with type II pleuropulmonary blastoma: successful treatment with surgery and chemotherapy.

Pleuropulmonary blastoma (PPB) is a very rare intrathoracic malignancy in childhood. It is an aggressive embryonal or blastemic neoplasm usually occurring in children younger than five years of age. PPB is treated with aggressive multimodal therapies consisting of surgery and chemotherapy. We present a case with PPB type II successfully treated with complete surgical resection following neoadjuvant chemotherapy. She has been free of disease for 33 months of follow-up. Complete surgical resection of the tumor at the time of diagnosis is the cornerstone of PPB management, but in the majority of patients, initial surgery is incomplete because a large tumor may involve vital structures. For this reason, patients with initially unresectable tumors should be treated with neoadjuvant chemotherapy to reduce the lesion to the point that it becomes resectable.

Value of Imaging Findings in the Prediction of Microvascular Invasion in Hepatocellular Carcinoma.

BACKGROUND: The purpose of this study was to determine the utility of some imaging findings in predicting microvascular invasion (MVI) and hepatocellular carcinoma (HCC) recurrence risk after liver transplantation. METHOD: This retrospective study included 123 patients with histopathologically proven HCC at explant. All HCCs were classified as MVI positive (group I) or negative (group II) based on histopathological findings. In each group, multifocality, largest tumor size, bulging (tumor causing liver capsule expansion), beak sign (the acute angle between the tumor and liver parenchyma), and diffusion restriction on diffusion weighted images (DWI) were evaluated. These findings were compared between the groups by Student's t test. The relation between the parameters and MVI was analyzed by using the Spearman's correlation test. RESULTS: Of the total patients, 30.1% had MVI (group I) and 69.9% (group II) did not have MVI. Presence of beak sign (P ≤ .005), bulging sign (P = .002), and diffusion restriction (P = .045) were significantly more frequent in group I than group II. The beak sign, bulging sign, and diffusion restriction were correlated with presence of MVI. Largest tumor size and multifocality were higher in group I than group II, but the differences were not statistically significant. CONCLUSION: Radiologists and transplant surgeons should be aware of some clue imaging findings, especially beak and bulging signs because these findings may predict the presence of MVI in HCC. These patients might benefit from histologic confirmation of the tumor characteristics through biopsy and subsequent bridging treatment options before liver transplantation to reduce the risk of recurrence.

Novel Application of Internal-External Drainage Catheter as Biliary Stent for Percutaneous Transhepatic Treatment of Biliary Strictures in Living Donor Liver Transplantation Recipient Patients.

OBJECTIVES: Although endoscopic management is considered as the first-line treatment for biliary strictures, it may be challenging in living donor liver transplant recipients due to the complex nature of duct-to-duct reconstruction. In this study we present the use of a pigtail drainage catheter as a biliary stent to treat biliary strictures after a living donor liver transplant. METHODS: Twenty-seven patients with biliary strictures were treated with our novel technique. In this technique, a pigtail catheter was trimmed into 3 parts (proximal, middle, and distal portions). A suture string was passed through the distal hole of the middle portion, which was then reversed and used as a stent while the proximal portion was used as a pusher. Following balloon dilation of the stenotic segment, the distal, reversed middle, and proximal portions were loaded over the guidewire. After proper placement of the stent, the retractor suture string, pusher, and guidewire were removed. The stent was removed during the third or fourth month of placement through endoscopic retrograde cholangiopancreatography (ERCP) in all patients. RESULTS: No significant complications developed during the procedure or follow-up period. Ten patients required re-stenting by ERCP during the same session. The mean follow-up period was 2 years. Cholestase enzymes and bilirubin levels were within normal limits in all patients during follow-up. CONCLUSION: Stents derived from drainage catheter facilitate treatment of biliary strictures in patients not eligible for the retrograde approach. This stent is cheap, easy to implement, can be easily removed by ERCP, and re-stenting can be applicable in retrograde if needed.

Intravoxel Incoherent Motion Parameters for Assessing the Efficiency of Locoregional Bridging Treatments before Liver Transplantation.

OBJECTIVE: To evaluate the diagnostic accuracy of Intravoxel Incoherent Motion (IVIM) parameters for assessment of tumor response after locoregional treatment (LRT) of hepatocellular carcinoma (HCC). METHODS: Fifteen patients with HCC who had undergone LRTs (11 transarterial radioembolization, 4 transarterial chemoembolization) were included. In addition to routine upper abdominal magnetic resonance imaging sequences, IVIM with 16 different b values and conventional diffusion weighted imaging with 3 different b factors were obtained immediately before and 8 weeks after LRTs. Magnetic resonance imaging response was evaluated according to modified Response Evaluation Criteria in Solid Tumors (mRECIST) and HCCs were categorized into 2 subgroups, responders and nonresponders. Quantitatively, the number of diffusion-changes were calculated with apparent diffusion coefficient (ADC) and IVIM parameters, including mean D (true diffusion coefficient), pseudo-diffusion coefficient associated with blood flow, and f (perfusion fraction) values. Subsequently, the pre- and post-treatment parameters were compared using the Mann-Whitney U test. RESULTS: Considering all HCCs, a significant decrease was observed according to mRECIST criteria (-38.43 ± 16.49). The ADC and D values after LRTs were significantly higher than those of the preceding ones. The f values after LRTs were significantly lower than those of pre-treatment. In the responders group, ADC and D values were significantly increased and f values were significantly decreased after LRTs. No difference of statistical significance was achieved in the nonresponders group. CONCLUSIONS: ADC values and IVIM parameters appear to reflect the response of LRTs as effectively as those of mRECIST. This promises new horizons in the management of pretransplant patients, especially in renal insufficiency clinical settings, owing to the elimination of contrast media administration.

Value of Intravoxel Incoherent Motion for Hepatocellular Carcinoma Grading.

BACKGROUND: To evaluate the diagnostic accuracy of intravoxel incoherent motion (IVIM) parameters in estimation of hepatocellular carcinoma (HCC) grading. MATERIALS AND METHODS: Twenty-nine patients with histopathologically diagnosed as 42 HCC at explant were included in this retrospective study. All patients were examined by 1.5T magnetic resonance imaging with the use of 4-channel phased array body coil. In addition to routine pre- and postcontrast sequences, IVIM (16 different b factors varying from 0 to 1300 s/mm2) and conventional diffusion-weighted imaging (3 different b factors of 50, 400, 800 s/mm2) were obtained with single-shot echo planar spin echo sequence. Apparent diffusion coefficient (ADC) and IVIM parameters including mean D (true diffusion coefficient), D* (pseudo-diffusion coefficient associated with blood flow), and f (perfusion fraction) values were calculated. Histopathologically, HCC was classified as low (grade 1, 2) and high (grade 3, 4) grade in accordance with the Edmondson-Steiner score. Quantitatively, ADC, D, D*, and f values were compared between the low- and high-grade groups by Student t test. The relationship between the parameters and histologic grade was analyzed using the Spearman's correlation test. To evaluate the diagnostic performance of the parameters, receiver operating characteristic analysis was performed. RESULTS: High-grade HCCs had significantly lower ADC and D values than low grade groups (P = .005 and P = .026, retrospectively); ADC and D values were inversely correlated with tumor grade (r = -0.519, P = .011, r = -0.510, P = .026, respectively). High-grade HCCs had significantly higher f values when compared with the low-grade group (P = .005). The f values were positively correlated with tumor grade (r = 0.548, P = .007). The best discriminative parameter was f value. Cut-off value of 32% of f values showed sensitivity of 75.6% and a specificity of 73.5%. CONCLUSION: ADC values and IVIM parameters such as f values appear to reflect the grade of HCCs.

Diffusion-weighted imaging in the differential diagnosis of cystic lesions of the pancreas.

OBJECTIVE: The purpose of our study was to evaluate the value of diffusion-weighted imaging (DWI) in the differential diagnosis of pancreatic cysts. SUBJECTS AND METHODS: Forty-two cysts (16 simple cysts, seven pseudocysts, five abscesses, three hydatid cysts, two serous cystadenomas, three mucinous cystadenomas, two mucinous cystadenocarcinomas, four cystic degenerated adenocarcinomas) were included in this prospective study. Single-shot spin-echo echo-planar DWI was performed with three b factors (0, 500, and 1,000 s/mm(2)), and apparent diffusion coefficients (ADCs) were calculated. On DWI, the signal intensity of the cysts was visually compared with the signal intensity of the pancreas parenchyma. For the quantitative evaluation, cyst-to-pancreas signal intensity ratios, ADC of the lesions, and cyst-to-pancreas ADC ratios were compared. RESULTS: On visual evaluation, all cystic lesions were hyperintense on DWI with b factors of 0 and 500 s/mm(2). On DWI with a b factor of 1,000 s/mm(2), all abscesses and hydatid and neoplastic cysts were hyperintense, whereas most of the simple and pseudocysts were isointense. Quantitatively, with b factors of 0 and 500 s/mm(2), no statistical significance was achieved. With a b factor of 1,000 s/mm(2), the cyst-to-pancreas signal intensity ratios of the abscesses and hydatid and neoplastic cysts were significantly higher than those of the simple cysts and pseudocysts. Setting the cutoff value of signal intensity ratio at 1.9, the cyst-to-pancreas signal intensity ratio had a sensitivity of 70% and a specificity of 90% for differentiating abscesses, hydatid cysts, and neoplastic cysts from simple cysts and pseudocysts. The ADC and the ADC ratios of the abscesses, hydatid cysts, and neoplastic cysts were significantly lower than those of the simple cysts and pseudocysts. CONCLUSION: DWI may help in the differential diagnosis of pancreatic cysts.

Dynamic contrast enhanced MRI in the differential diagnosis of adrenal adenomas and malignant adrenal masses.

OBJECTIVE: To evaluate the value of dynamic MR imaging in the differential diagnosis of adrenal adenomas and malignant tumors, especially in cases with atypical adenomas. MATERIALS AND METHODS: Sixty-four masses (48 adenomas, 16 malignant tumors) were included in this prospective study. Signal loss of masses was evaluated using chemical shift MR imaging. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, with the acquisition starting simultaneously with i.v. contrast administration (0-100 s) followed by a T1-weighted FFE sequence in the late phase (5th minute). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained according to the SIs on the 0th, 25th, 50th 75th and 100th second. Also, the wash-in rate, maximum relative enhancement, time-to-peak, and wash-out of contrast at 100 s of masses in both groups were calculated. The statistical significance was determined by Mann-Whitney U test. To evaluate the diagnostic performance of the quantitative tests, receiver operating characteristic (ROC) analysis was performed. RESULTS: Chemical shift MR imaging was able to differentiate 44 out of 48 adenomas (91.7%) from non-adenomas. The 4 adenomas (8.3%) which could not be differentiated from non-adenomas by this technique did not exhibit signal loss on out-of-phase images. With a cut-off value of 30, SI indices of adenomas had a sensitivity of 93.8%, specificity of 100% and a positive predictive value of 100%. On visual evaluation of dynamic MR imaging, early phase contrast enhancement patterns were homogeneous in 75% and punctate in 20,83% of the adenomas; while patchy in 56.25% and peripheral in 25% of the malignant tumors. On the late phase images 58.33% of the adenomas showed peripheral ring-shaped enhancement and 10.41% showed heterogeneous enhancement. All of the malignant masses showed heterogeneous enhancement. At the 25th second, the SIs and wash-in rates of the adenomas were significantly higher than those of the malignant masses (p=0.010). Time-to-peak enhancement of the malignant masses was significantly longer than that of the adenomas. With a cut-off value of 52.85 s, the time-to-peak enhancement had 87.5% sensitivity and 80% specificity. CONCLUSION: Chemical shift MR has a high sensitivity and specificity in the differential diagnosis of adenomas and malignant adrenal masses. However, taking into consideration only the atypical adenomas, chemical shift MRI is of no diagnostic value. Although the diagnostic value of dynamic MRI is lower than chemical shift MRI, in the atypical cases contrast enhancement patterns and time-to-peak and wash-in rates derived from SI-time curve of dynamic MRI give are contributory to the results of chemical shift MRI.

Color Doppler ultrasonographic flow parameters in the differentiation of benign and malignant causes of omental thickening.

OBJECTIVE: The purpose of the study was to determine if color Doppler ultrasonographic (US) quantitative flow parameters are valuable to differentiate malignant peritoneal or omental involvement from benign causes. MATERIALS AND METHODS: Twenty-six consecutive patients with peritoneal or omental thickening detected by gray scale US, computed tomography, and magnetic resonance underwent color Doppler US examinations. All the Doppler signal waveforms were recorded, and resistive (RI) and pulsatility indices (PI) were calculated automatically by the US machine. In the statistical analysis of RI and PI, unpaired t test was used. A P < 0.05 was considered significant. RESULTS: Nineteen of 20 malignant and 5 of 6 benign lesions had detectable color Doppler US pulsatile flow signals. The mean RI and PI values were 0.6260 and 1.36, respectively, for the benign group and 0.5384 and 1.4147, respectively, for the malignant group. For malignant lesions, mean RI was lower (P = 0.0796), and mean PI was higher (P = 0.9183) than benign lesions. However, these differences were not statistically significant. CONCLUSIONS: Overlapping RI and PI values in benign and malignant omental lesions limit the clinical value of flow parameters in the differentiation of benign and malignant involvement of the omentum.

Unusual magnetic resonance image of an insulinoma with extensive desmoplastic reaction.

CONTEXT: Unlike other islet-cell tumors, insulinomas are usually benign. Most insulinomas have a high signal intensity on T2-weighted images and a low signal intensity on T1-weighted images, and are hyperintense on immediate post-gadolinium images. However, in rare cases, insulinomas may be hypointense on T2-weighted images and on immediate post-gadolinium images, mimicking a ductal adenocarcinoma. CASE REPORT: We present a case of a surgically proven insulinoma which was hypointense on both T2-weighted and immediate post-gadolinium T1-weighted images, but hyperintense on late phase T1-weighted images. Histopathological examination of the surgical specimen revealed a prominent desmoplastic reaction which accounted for the low signal on T2-weighted images and the contrast enhancement pattern. Delayed contrast enhancement reflects the desmoplastic component of this tumor. CONCLUSIONS: Insulinomas with an extensive desmoplastic reaction may appear hypointense on T2-weighted images with minimal enhancement on immediate post-gadolinium images. Late phase fat-suppressed T1-weighted post-gadolinium images may be useful in the detection of such tumors.

Response to rituximab and prednisolone for opsoclonus-myoclonus-ataxia syndrome in a child with ganglioneuroblastoma.

Opsoclonus-myoclonus-ataxia (OMA) syndrome is a rare neurobehavioral paraneoplastic disorder in children with neuroblastic tumors. The neurologic symptoms are generally treated with a number of immunosupressive and immunomodulating agents. A 4-year-old previously healthy male patient was admitted to the authors' center with progressive ataxia, gait disturbance, difficulty of speech, and opsoclonus. He had a diagnosis of ganglionueroblastoma at the thoracal paraspinal region. Following surgery, the patient received IVIG and prednisolone but his cerebellar symptoms progressed. Rituximab therapy was started and continued for total 8 weeks without any side effect. The authors observed excellent neurologic response in the patient at the 4th week of treatment. Rituximab is a new, promising, and safe therapy for OMA syndrome in children with neuroblastoma.