Reproducibility of mRECIST in assessing response to transarterial radioembolization therapy in hepatocellular carcinoma.

UNLABELLED: The purpose of our study was to evaluate the reproducibility of Modified Response Evaluation Criteria in Solid Tumors (mRECIST) in hepatocellular carcinoma (HCC) lesions undergoing transarterial radioembolization (TARE) therapy and to determine whether mRECIST reproducibility is affected by the enhancement pattern of HCC. One hundred and three HCC lesions from 103 patients treated with TARE were evaluated. The single longest diameter of viable tumor tissue was measured by two radiologists at baseline; response to therapy was evaluated according to mRECIST. The enhancement pattern of HCC lesions was correlated with their mRECIST response. The response rate between mRECIST and RECIST 1.1 was compared. Wilcoxon signed-rank test, paired t test, Lin's concordance correlation coefficient (ρc ), Bland-Altman plot, kappa statistics, and Fisher's exact test were used to assess intra- and interobserver reproducibilities and to compare response rates. There were better intra- than interobserver agreements in the measurement of single longest diameter of viable tumor tissue (bias = 0 cm intraobserver versus bias = 0.3 cm interobserver). For mRECIST, good intraobserver (ĸ = 0.70) and moderate interobserver (ĸ = 0.56) agreements were noted. The mRECIST response for HCC lesions with homogeneous enhancement at both baseline and follow-up imaging showed better intra- and interobserver agreements (ĸ = 0.77 and 0.60, respectively) than lesions with heterogeneous enhancement at both scans (ĸ = 0.54 and 0.40, respectively). In the early follow-up period mRECIST showed a significantly higher response rate than RECIST (40.8% versus 3.9%; P = 0.025). CONCLUSIONS: In HCC patients treated with TARE, mRECIST captures a significantly higher response rate compared with RECIST; it also demonstrates acceptable intra- and interobserver reproducibilities for HCC lesions treated with TARE, and mRECIST reproducibility may be lower for HCC lesions with heterogeneous distribution of the viable tumor tissue.

Threshold for Enhancement in Treated Hepatocellular Carcinoma on MDCT: Effect on Necrosis Quantification.

OBJECTIVE: The objective of our study was to determine whether the conventionally used enhancement threshold of 10 HU for assessing tumor viability in treated hepatocellular carcinoma (HCC) lesions is valid. MATERIALS AND METHODS: To distinguish pseudoenhancement from enhancement in a tumor, we used an in vivo model: The attenuation of 54 hepatic cysts during the unenhanced and portal venous phases of MDCT, similar to what may be observed in HCC with central necrosis, was used to determine the threshold for pseudoenhancement. To validate this model, we compared the attenuation value of liver parenchyma in this cohort with that of 22 HCCs during the late arterial phase of enhancement. We tested the effect of this pseudoenhancement on quantifying necrosis in HCC compared with the conventionally used threshold of 10 HU. RESULTS: Values of enhancing HCC tissue on arterial phase MDCT (mean, 121.3 HU) were comparable with normal liver parenchyma on venous phase MDCT (117.3 HU) (p = 0.27). The threshold of 17.1 HU was the best threshold for the detection of pseudoenhancement in cysts (99% accuracy, 100% sensitivity, and 98% specificity). When this threshold was used instead of the conventional threshold of 10 HU, the mean necrosis proportion of treated HCC increased from 34.0% to 42.6% and the mean viable tumor proportion decreased from 66.0% to 57.4%. The quantification of viable HCC tissue based on 10 HU and the quantification of viable HCC tissue based on 17.1 HU were found to be significantly different (p < 0.0001). CONCLUSION: The threshold of 17.1 HU may be the appropriate cutoff for nonenhancement in a necrotic HCC. Use of this threshold may potentially affect how response to therapy is quantified and categorized.

Current Guidelines for the Diagnosis and Management of Hepatocellular Carcinoma: A Comparative Review.

OBJECTIVE: The purpose of this article is to review aspects of guidelines pertinent to radiologists involved in the diagnosis or treatment of hepatocellular carcinoma. CONCLUSION: Early diagnosis and treatment of hepatocellular carcinoma are important because only 10% of patients meet the criteria for curative therapy at the time of diagnosis. Several organizations have developed guidelines for screening, diagnosis, and treatment of hepatocellular carcinoma. Radiologists play a pivotal role in every aspect of these guidelines.

CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach.

Recent innovations in computed tomographic (CT) hardware and software have allowed implementation of low tube voltage imaging into everyday CT scanning protocols in adults. CT at a low tube voltage setting has many benefits, including (a) radiation dose reduction, which is crucial in young patients and those with chronic medical conditions undergoing serial CT examinations for disease management; and (b) higher contrast enhancement. For the latter, increased attenuation of iodinated contrast material improves the evaluation of hypervascular lesions, vascular structures, intestinal mucosa in patients with bowel disease, and CT urographic images. Additionally, the higher contrast enhancement may provide diagnostic images in patients with renal dysfunction receiving a reduced contrast material load and in patients with suboptimal peripheral intravenous access who require a lower contrast material injection rate. One limitation is that noisier images affect image quality at a low tube voltage setting. The development of denoising algorithms such as iterative reconstruction has made it possible to perform CT at a low tube voltage setting without compromising diagnostic confidence. Other potential pitfalls of low tube voltage CT include (a) photon starvation artifact in larger patients, (b) accentuation of streak artifacts, and (c) alteration of the CT attenuation value, which may affect evaluation of lesions on the basis of conventional enhancement thresholds. CT of the abdomen with a low tube voltage setting is an excellent radiation reduction technique when properly applied to imaging of select patients in the appropriate clinical setting.

Performance of tumor growth kinetics as an imaging biomarker for response assessment in colorectal liver metastases: correlation with FDG PET.

PURPOSE: To correlate RECIST, volumetric criteria, and tumor growth kinetics at multidetector-computed tomography with tumor metabolic activity at FDG PET in colorectal liver metastases (CRCLM) treated with bevacizumab-based chemotherapy. METHODS: Thirty-two CRCLM in 20 patients treated with bevacizumab-based chemotherapy were evaluated. Pre- and post-treatment CT scans were used to calculate reciprocal of doubling time (RDT), percentage change in the lesion's longest transaxial diameter (RECIST 1.1), and percentage change in the tumor volume. The accuracy of these parameters in predicting response based on standard uptake value analysis at FDG PET was assessed. Data were analyzed using Spearman's correlation, student's t, Mann-Whitney, Wilcoxon signed-rank, and Fisher's exact tests. RESULTS: According to FDG PET, 24/32 (75%) lesions were categorized as responders and 8/32 (25%) lesions as nonresponders. Based on RDT, 26/32 (81.25%) lesions were classified as responders and 6/32 (18.75%) lesions as nonresponders. Response classification according to RDT and FDG PET was concordant in 30/32 (93.75%) lesions, whereas RECIST 1.1 and volumetric criteria were concordant with FDG PET for 20/32 (62.5%) and 21/32 (65.63%) lesions, respectively. A strong association was found between RDT and response based on FDG PET (odds ratio = 127.4; 95% CI 5.54-2997; P < 0.0001). CONCLUSIONS: Tumor growth kinetics may be an effective imaging biomarker for response evaluation in CRCLM.

Imaging findings of bisphosphonate-related osteonecrosis of the jaw with emphasis on early magnetic resonance imaging findings.

PURPOSE: To describe the imaging findings of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with emphasis on early magnetic resonance imaging (MRI) findings. MATERIALS AND METHODS: The medical records and computed tomography, MRI, and bone scintigraphy images of 5 female and 1male patients (n = 6) between the ages of 49 and 79 years (mean age, 70 years) who had a diagnosis of BRONJ were retrospectively reviewed, and temporal changes in imaging features were noted. RESULTS: The earliest MRI finding was the loss of the normal T1 hyperintensity of fatty marrow in the mandible and maxilla. The MRI findings of more advanced BRONJ included bone destruction, soft tissue edema and enhancement, inferior alveolar nerve thickening, and pterygoid muscle swelling and enhancement. On computed tomography, sclerosis and subtle lucencies (widening) of the periodontal ligament and cortex and around the apices of the teeth in the early stage, and osteolytic bone lesions, cortical disruption, and frank bone fragmentation in the later stages were observed. Bone scintigraphy showed increased uptake early in the disease. CONCLUSIONS: Osteonecrosis of the mandible and maxilla occurs as a complication of bisphosphonate treatment of bone metastasis and osteoporosis and typically manifests after a dental procedure. Magnetic resonance imaging and bone scintigraphy findings may precede clinical symptoms and mimic metastatic disease.

Klippel-Feil syndrome and associated ear anomalies.

BACKGROUND AND PURPOSE: Klippel-Feil syndrome (KFS) is a congenital segmentation anomaly of the cervical vertebrae that manifests as short neck, low hair line, and limited neck mobility. Various systemic malformations may also accompany the syndrome including wide variety of otopathologies affecting all 3 compartments of the ear (external, middle, and inner ear) as well as internal acoustic canal and vestibular aqueduct. We aimed to investigate these involvements and their clinical correlates in a group of patients with KFS. MATERIALS, METHODS, AND RESULTS: We present 20 KFS cases, of which 12 (% 60) displayed most of the reported ear abnormalities such as microtia, external ear canal stenosis, chronic ear inflammations and their sequels, anomalies of the tympanic cavity and ossicles, inner ear dysplasies, deformed internal acoustic canal, and wide vestibular aqueduct, which are demonstrated using the methods of otoscopy, audiologic testing, and temporal bone computed tomography. CONCLUSIONS: This series represents one of the highest reported rate of ear involvement in KFS. We found no correlation between the identified ear pathologies and the skeletal and extraskeletal malformations. The genetic nature of the syndrome was supported by the existence of affected family members in 4 (20%) of the cases.

Carcinoid tumor of the middle ear: report of a case.

Carcinoid tumor of the middle ear is an extremely rare lesion of the middle ear, and thus its diagnosis is frequently delayed. Some authors found it hard to differentiate middle ear carcinoid from the middle ear adenoma. However, the balance of opinion is currently on the side of considering it as a separate clinical entity. Definitive diagnosis is made by identifying neurosecretory tumor cells using immunohistochemistry and electron microscopy. It usually follows a nonaggressive clinical course, rarely metastases, and infrequently recurs after radical excisions. We present a patient with middle ear carcinoid, who is free of disease 2 years after the resection of the tumor mass with canal wall-down procedure. The relevant literature is also herewith reviewed.

Interlaminar discectomy in lumbar disc herniation: shorten postoperative return to work period in recruits undergoing military training.

The operative treatment of lumbar disc disease has long challenged spine surgeons. In this study, we aimed to show that recruits with lumbar disc herniation managed by the interlaminar approach could return to work after 6 weeks. Forty male recruits were included in this study and interlaminar discectomy was adequate in 40 cases. Early postoperative rehabilitation had a positive effect on early return to work. We believe that interlaminar lumbar discectomy is an effective technique for treating patients with herniated lumbar discs; with early postoperative rehabilitation, recruits can return to work 6 weeks after surgery.

Decreased Tc-99m sestamibi uptake in a sternal brown tumor indicating response to anti metabolic therapy for secondary hyperparathyroidism.

Brown tumors are rare but serious complications of renal osteodystrophy, and can be treated by parathyroidectomy or by pharmacological treatment of hyperparathyroidism. In addition to parathyroid lesions such as adenoma, hyperplasia, and carcinoma, brown tumors have been detected effectively by using dual phase Tc-99m sestamibi and Tl-201 chloride. We describe an unusual case of brown tumor at the manibrium sterni which shows marked increased Tc-99m sestamibi uptake on the initial scan, with decreasing tracer activity on follow-up scan indicating a response to antimetabolic therapy.

Doctors' and intern doctors' knowledge about patients' ionizing radiation exposure doses during common radiological examinations.

PURPOSE: To investigate the level of doctors' and intern doctors' knowledge about patients' radiation exposure doses during common radiological examinations. MATERIALS AND METHODS: A questionnaire listing the radiation doses of routine radiological diagnostic procedures was administered to 177 doctors and intern doctors. We asked them to find the equivalent doses of radiation for common radiological examinations when a normal chest X-ray is accepted as one unit. Data were analyzed with k-square and Fisher's exact k-square tests. RESULTS: In all, 93.1% (n = 156) of the doctors and intern doctors underestimated the actual radiation dose, 4% (n = 7) did not know that ultrasound does not utilize ionizing radiation, and 27.4% (n = 47) did not know that magnetic resonance imaging does not entail ionizing radiation. CONCLUSION: Most of the doctors and intern doctors underestimated real radiation doses. This lack of awareness may cause doctors to order more radiological investigations than they would if properly educated. Therefore, we propose mandatory education about radiation protection in the medical school.

Gross mural cartilage in a congenital bronchogenic cyst: MRI features.

An infant who had a cardiac murmur after the delivery was evaluated with echocardiogram. A 1 cm cystic area was incidentally identified in the upper right mediastinum, that was not related with the heart. A 4 x 4.5 x 8 cm cystic mass in the superior mediastinum and lower neck was demonstrated on the magnetic resonance imaging (MRI). At surgery, a small solid structure corresponding to the nodule seen on MRI was identified, which was firm and cartilaginous in nature and attached to the wall of the cyst. Grossly visible cartilage in association with a bronchogenic cyst has not been previously reported. In conclusion, the bronchogenic cysts can have grossly visible cartilage in their wall and extend to extrathoracic spaces in a contiguous fashion, mimicking other entities such as teratomas and cystic lymphangiomas.

Imaging findings of CNS atypical teratoid/rhabdoid tumors.

Four patients with brain tumors were diagnosed with atypical teratoid/rhabdoid tumors and underwent CT and MR imaging. For all tumors, aggressive features were shown by imaging studies and included hydrocephalus, apparent invasion of the adjacent brain and dura, and marked mass effect. The striking heterogeneity of the atypical teratoid/rhabdoid tumor shown by imaging studies reflects the histopathologic complexity of these tumors, and awareness of atypical teratoid/rhabdoid tumor is important in making the correct diagnosis of this uncommon but probably underdiagnosed entity.

MR imaging characteristics of pilomyxoid astrocytomas.

BACKGROUND AND PURPOSE: Pilomyxoid astrocytoma (PMA) is a recently described tumor that typically occurs in the chiasmatic-hypothalamic region in young children and has unique histopathologic and clinical characteristics. These tumors have been previously diagnosed as pilocytic astrocytoma (PA). PMA appears to have a higher rate of recurrence and CSF dissemination than typical PA. METHODS: We analyzed MR findings in four patients with PMA and compared them with those of typical chiasmatic-hypothalamic PA. RESULTS: MR findings of PMA were chiasmatic or hypothalamic enhancing solid tumor with hydrocephalus, highly homogeneous T2 signal intensity that extended into the deep white and gray matter, and CSF dissemination. CONCLUSION: Larger series are needed before the MR imaging findings of chiasmatic or hypothalamic enhancing solid tumor with hydrocephalus, highly homogeneous T2 signal intensity extending into the deep white and gray matter, and CSF dissemination can be used in the differential diagnosis of such tumors.

Trigeminal neuralgia caused by intracranial epidermoid tumor: report of a case and review of the different therapeutic modalities.

Trigeminal neuralgia (TGN) is characterized by recurrent paroxysms of unilateral facial pain that typically is severe, lancinating, and activated with cutaneous stimulation. Paroxysms typically last for 1 to 2 seconds. Etiology includes compression of the trigeminal nerve by vascular structures, tumors and multiple sclerosis plaques in the medulla spinalis. TGN is rather rare as a presenting symptom with intracranial tumors. Epidermoid tumors comprise 1% of all intracranial tumors. The majority of epidermoid tumors are located at the pontocerebellar angle, the third ventricle, and the suprasellar region. Symptomatology is not different from other tumors located at the same sites. Trigeminal neuralgia may be caused by tumor compressing the nerve itself, an inflammatory response to the epidermoid tumor or vascular compression of the nerve. We describe the case of a 30-year old female presenting with right-sided facial pain. Her past history revealed multiple teeth extractions done to relieve facial pain. Radiological evaluation, including magnetic resonance imaging (MRI), showed a pontocerebellar angle (PCA) epidermoid tumor. TGN resolved completely after total tumor resection. A temporary facial paralysis consequent to surgical removal of the tumor improved 6 months postoperatively, and she remained painfree, without medications.

Polyorchidism: color Doppler ultrasonography and magnetic resonance imaging findings.

Polyorchidism, the presence of more than two testes, is a very rare anomaly. We report the color Doppler ultrasonography and magnetic resonance imaging findings of the case of a 20-year-old man with polyorchidism, presenting with an asymptomatic scrotal mass. Ultrasonography showed double testes with double separate epididymides sharing a common vas deferens in the left side of the scrotum. The double testes demonstrated similar echo texture and vascular flow as the normal testis, but smaller in size. Magnetic resonance imaging showed three testes very clearly and confirmed the diagnoses. After 2 years of follow-up, he was managed with surgical intervention. Pathology report revealed polyorchidism.

Otologic and leptomeningeal involvements as presenting features in seronegative Wegener granulomatosis.

Wegener granulomatosis is an immune-mediated, systemic vasculitis with unknown etiology that can be seen in almost any anatomical site. Positivity for antineutrophil cytoplasmic antigene, which is a serological marker, and presence of granulomatous vasculitis in histopathologic specimens from the lesions are accepted as diagnostic. A case of Wegener granulomatosis whose presenting symptoms and signs are related to otologic and meningeal involvement of the disease is reported. Apart from atypical presentation, histopathological and serological findings from this patient remained negative throughout the course of the disease, and the diagnosis was made on the basis of clinical and secondary laboratory findings. We herewith discuss this unusual case in the light of relevant literature.

Rhinolithiasis: clinical, radiological, and mineralogical features.

BACKGROUND: Rhinolithiasis is a rare and under-diagnosed clinical entity whose etiology and pathogenesis is poorly understood. OBJECTIVE: The objective of the study is to review the clinical and radiologic features of rhinolithiasis and mineralogical-chemical composition of the rhinoliths with the aim of shedding light on its etiology and pathogenesis. METHODS: Our subjects consisted of 8 rhinolithiasis cases. Clinical presentations, signs, and symptoms of the patients with radiologic findings are presented, and X-ray diffraction analyses of the stones were carried out to assess their mineralogical composition. RESULTS: Nasal obstruction appeared to be the chief symptom, followed by nasal discharge and facial pain. Neither exogenous nor endogenous nidi were identified in any of the cases. Mineralogical analyses of the rhinoliths revealed Whitlockite [(Ca,Mg)3 (PO4)2] in one and Dahllite [Ca5 (PO4,CO3)3OH] in 7 cases. CONCLUSION: We hypothesized that some substances or organic objects form the nidi of the rhinoliths and are disintegrated over the course of mineral precipitation. This hypothesis was supported by radiologic and microscopic findings.

Fast method for brain image segmentation: application to proton magnetic resonance spectroscopic imaging.

The interpretation of brain metabolite concentrations measured by quantitative proton magnetic resonance spectroscopic imaging (MRSI) is assisted by knowledge of the percentage of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) within each MRSI voxel. Usually, this information is determined from T(1)-weighted magnetic resonance images (MRI) that have a much higher spatial resolution than the MRSI data. While this approach works well, it is time-consuming. In this article, a rapid data acquisition and analysis procedure for image segmentation is described, which is based on collection of several, thick slice, fast spin echo images (FSE) of different contrast. Tissue segmentation is performed with linear "Eigenimage" filtering and normalization. The method was compared to standard segmentation techniques using high-resolution 3D T(1)-weighted MRI in five subjects. Excellent correlation between the two techniques was obtained, with voxel-wise regression analysis giving GM: R2 = 0.893 +/- 0.098, WM: R2 = 0.892 +/- 0.089, ln(CSF): R2 = 0.831 +/- 0.082). Test-retest analysis in one individual yielded an excellent agreement of measurements with R2 higher than 0.926 in all three tissue classes. Application of FSE/EI segmentation to a sample proton MRSI dataset yielded results similar to prior publications. It is concluded that FSE imaging in conjunction with Eigenimage analysis is a rapid and reliable way of segmenting brain tissue for application to proton MRSI.

Quantitative proton MR spectroscopic imaging of the mesial temporal lobe.

PURPOSE: To evaluate variations in regional metabolite concentrations in the anterior mesial temporal lobe (ATL), and compare metabolite concentrations between the allocortex and neocortex using quantitative proton MR spectroscopic imaging (MRSI). MATERIALS AND METHODS: Metabolite concentrations and ratios were measured in 20 healthy young subjects with the use of a multislice spin-echo (SE) sequence (TR/TE=2300/280 msec). Quantitation of MRSI data was performed by means of the phantom replacement methodology. RESULTS: The highest choline (Cho) concentration (4.1 +/- 1.1 mM) was found in the ATL (P=0.0015 compared to the middle mesial temporal lobe (MTL), and P=0.0008 compared to the posterior mesial temporal lobe (PTL)). The ATL also had a higher Cho/creatine (Cr) ratio and a lower N-acetyl aspartate (NAA)/Cho ratio compared to other examined regions (P <0.0001 and P < or = 0.052, respectively). In the allocortical regions, the average Cho concentration (3.5 +/- 0.8 mM) was 68% higher, and the NAA concentration (9.5 +/- 1.8 mM) was 13% lower than in the neocortex (P <10(-6) and P <0.008, respectively). Cho/Cr was 64% higher, NAA/Cr 14% lower, and NAA/Cho 47% lower in the allocortex than in the neocortex (P <10(-6), P=0.013, and P <10(-6), respectively). CONCLUSION: The mesial temporal lobe shows high levels of Cho, which presumably reflect a difference in cellular composition between the allocortex and neocortex. Regional metabolite variations must be considered when pathological conditions involving the mesial temporal lobe are evaluated.