Recurrent Optic Perineuritis after Intranasal Cocaine Abuse.

Recurrent optic perineuritis can be related to orbital inflammation. Here we present the case of a 46-year-old male patient in whom recurrent episodes of optic perineuritis were related to chronic osteolytic sinusitis following intranasal cocaine abuse. Magnetic resonance imaging (MRI) demonstrated optic perineuritis adjacent to a soft tissue mass that intruded the orbit from the nasal cavity. Computed tomography (CT) confirmed destruction of the medial orbital wall. Staphylococcus aureus was cultured and biopsy showed granulomatous tissue. Visual outcome was poor. We review the literature and discuss the diagnostic pitfalls and management implications in relation to optic (peri)neuritis originating from the nasal sinuses.

Results of surgery for perforated gastroduodenal ulcers in a Dutch population.

OBJECTIVE: Despite improvements in anesthesiology and intensive care medicine, mortality for perforated gastroduodenal ulcer disease remains high. This study was designed to evaluate the results of surgery for perforated ulcer disease and to identify prognostic factors for mortality in order to optimize treatment. PATIENTS AND METHODS: The medical records of 272 patients undergoing emergency surgery for perforated ulcer disease from 2000 to 2005 in two large teaching hospitals and one university hospital in the Netherlands were retrospectively analyzed. Information on 89 pre-, peri- and postoperative data were recorded. Statistical analysis was performed using multiple logistic regression analysis. The primary endpoint was 30-day mortality. RESULTS: The 30-day mortality rate was 16%. Variables associated with 30-day mortality were age, shock, tachycardia, anemia and ASA class. CONCLUSIONS: A relatively low 30-day mortality rate was achieved. Age, shock, tachycardia and anemia were significantly associated with 30-day mortality. Finding that shock, tachycardia and anemia are independently associated with 30-day mortality could indicate that patients are septic upon admission. Improvements in survival might be achieved by early sepsis treatment.

Surgeon-performed ultrasound as preoperative localization study in patients with primary hyperparathyroidism.

BACKGROUND: Minimally invasive parathyroidectomy is the treatment of choice for single-gland primary hyperparathyroidism. However, the exact location of the abnormal gland has to be established. Sestamibi scintigraphy, computed tomography and ultrasound (US) are commonly used modalities. We describe our experience in a non-academic center with surgeon-performed US (S-US) of the neck as preoperative localization study in patients with primary hyperparathyroidism (PHPT). METHODS: Patients with a biochemically proven diagnosis of PHPT and preoperative S-US were included. Data were recorded prospectively. Perioperative gland location was compared to the preoperative S-US to determine sensitivity, specificity and accuracy rates. RESULTS: Two of the 50 patients who underwent S-US were not subjected to surgery. In 85% of the patients analyzed by S-US, the appropriate abnormal gland(s) were identified. In 11%, no gland was identified, but abnormal glands were found during surgery. Sensitivity of S-US in our hospital is 85%, with a positive predictive value of 97%. CONCLUSIONS: We achieved a satisfactory sensitivity rate. S-US provides anatomic information to the surgeon which enables a more detailed operation planning, and it is a valuable diagnostic modality for patients with PHPT in our opinion. We hope that our data encourage other centers to implement this technique as well.

Intra-operative parathyroid hormone measurements - experience of a non-academic hospital.

BACKGROUND: Surgery is the treatment of choice for symptomatic primary hyperparathyroidism. The majority of research concerning intra-operative parathyroid hormone (ioPTH) measurements is conducted in university hospitals. Whether ioPTH measurements are feasible and useful in predicting the presence of remaining hyperfunctioning parathyroid tissue in a non-academic hospital remains uncertain. METHODS: Data were collected on all patients with biochemically proven and surgically treated primary hyperparathyroidism treated at the Reinier de Graaf Hospital from August 2002 to December 2007. RESULTS: Sixty-five patients were included. The mean pre-operative serum calcium level was 2.78 mmol/l (range 2.28 - 3.80 mmol/l, normal range 2.20 - 2.65 mmol/l) and the mean serum parathyroid hormone level 17.0 pmol/l (range 4.0 - 90.3 pmol/l, normal range 1.0 - 5.5 pmol/l). All patients were operated on for primary hyperparathyroidism, using ioPTH measurements during their first operation. Sensitivity and specificity rates of ioPTH measurements were 98% and 89%, respectively. The ioPTH test accurately indicated incomplete removal of all hyperfunctioning parathyroid tissue in 8 patients (12%). Five patients (8%) were re-explored immediately, of whom 4 were successfully treated in this single operative session. One patient was operated on successfully the next day. Two patients were operated on with a successful result during a second admission. In all the ioPTH measurements there was 1 false-positive result (1.5%) and 1 false-negative result (1.5%). The mean postoperative calcium value for the successfully treated patients was 2.34 mmol/l (range 2.14 - 2.71 mmol/l, normal range 2.20 - 2.65 mmol/l). The mean postoperative PTH level for the successfully treated patients was 3.76 pmol/l (range 0.40 - 7.1 pmol/l). CONCLUSION: Our data suggest that ioPTH measurements are feasible and useful in a non-academic hospital.

Validation of 70-gene prognosis signature in node-negative breast cancer.

PURPOSE: The 70-gene prognosis signature (van't Veer et al., Nature 415(6871):530-536, 2002) may improve the selection of lymph node-negative breast cancer patients for adjuvant systemic therapy. Optimal validation of prognostic classifiers is of great importance and we therefore wished to evaluate the prognostic value of the 70-gene prognosis signature in a series of relatively recently diagnosed lymph node negative breast cancer patients. METHODS: We evaluated the 70-gene prognosis signature in an independent representative series of patients with invasive breast cancer (N = 123; <55 years; pT1-2N0; diagnosed between 1996 and 1999; median follow-up 5.8 years) by classifying these patients as having a good or poor prognosis signature. In addition, we updated the follow-up of the node-negative patients of the previously published validation-series (Van de Vijver et al., N Engl J Med 347(25):1999-2009, 2002; N = 151; median follow-up 10.2 years). The prognostic value of the 70-gene prognosis signature was compared with that of four commonly used clinicopathological risk indexes. The endpoints were distant metastasis (as first event) free percentage (DMFP) and overall survival (OS). RESULTS: The 5-year OS was 82 +/- 5% in poor (48%) and 97 +/- 2% in good prognosis signature (52%) patients (HR 3.4; 95% CI 1.2-9.6; P = 0.021). The 5-years DMFP was 78 +/- 6% in poor and 98 +/- 2% in good prognosis signature patients (HR 5.7; 95% CI 1.6-20; P = 0.007). In the updated series (N = 151; 60% poor vs. 40% good), the 10-year OS was 51 +/- 5% and 94 +/- 3% (HR 10.7; 95% CI 3.9-30; P < 0.01), respectively. The DMFP was 50 +/- 6% in poor and 86 +/- 5% in good prognosis signature patients (HR 5.5; 95% CI 2.5-12; P < 0.01). In multivariate analysis, the prognosis signature was a strong independent prognostic factor in both series, outperforming the clinicopathological risk indexes. CONCLUSION: The 70-gene prognosis signature is also an independent prognostic factor in node-negative breast cancer patients for women diagnosed in recent years.

Helicobacter genotyping and detection in peroperative lavage fluid in patients with perforated peptic ulcer.

INTRODUCTION AND OBJECTIVES: Certain Helicobacter pylori genotypes are associated with peptic ulcer disease; however, little is known about associations between the H. pylori genotype and perforated peptic ulcer (PPU). The primary aim of this study was to evaluate which genotypes are present in patients with PPU and which genotype is dominant in this population. The secondary aim was to study the possibility of determining the H. pylori status in a way other than by biopsy. MATERIALS AND METHODS: Serum samples, gastric tissue biopsies, lavage fluid, and fluid from the nasogastric tube were collected from patients operated upon for PPU. By means of PCR, DEIA, and LIPA the presence of the "cytotoxin associated gene" (cagA) and the genotype of the "vacuolating cytotoxin gene" were determined. RESULTS: Fluid from the nasogastric tube was obtained from 25 patients, lavage fluid from 26 patients, serum samples from 20 patients and biopsies from 18 patients. Several genotypes were found, of which the vacA s1 cagA positive strains were predominant. Additionally, a correlation was found between the H. pylori presence in biopsy and its presence in lavage fluid (p=0.015), rendering the latter as an alternative for biopsy. Sensitivity and specificity of lavage fluid analysis were 100% and 67%, respectively. CONCLUSION: This study shows the vacA s1 cagA positive strain is predominant in a PPU population. The correlation found between the H. pylori presence in biopsy and its presence in lavage fluid suggests that analysis of the lavage fluid is sufficient to determine the H. pylori presence. Risks associated with biopsy taking may be avoided.

Use of Diffusion-Weighted Imaging and 18F-Fluorodeoxyglucose Positron Emission Tomography Combined With Computed Tomography in the Response Assessment for (Chemo)radiotherapy in Head and Neck Squamous Cell Carcinoma.

AIMS: Our purpose was to assess the diagnostic accuracy and prognostic value of diffusion-weighted imaging (DWI) and 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (18F-FDG-PET/CT) carried out 3-6 months after (chemo)radiotherapy in head and neck squamous cell carcinoma. MATERIALS AND METHODS: For this retrospective cohort study we included 82 patients with advanced-stage head and neck squamous cell carcinoma treated between 2012 and 2015. Primary tumours and lymph nodes were assessed separately. DWI was analysed qualitatively and quantitatively. 18F-FDG-PET/CT was evaluated using the Hopkins criteria. Dichotomous qualitative analysis was carried out for both modalities. Cox regression analysis was used for univariate analysis of recurrence-free survival (RFS). Significant univariate parameters were included in multivariate analysis. RESULTS: In 12 patients, locoregional recurrence occurred. With all imaging strategies, either single-modality or multi-modality, a high negative predictive value (NPV) was achieved (94.3-100%). In response evaluation of the primary site, the preferred strategy is 18F-FDG-PET/CT only, which resulted in a sensitivity of 85.7%, specificity of 86.5%, positive predictive value (PPV) of 37.5% and NPV of 98.5%. For response evaluation of the neck, the best results were obtained with a sequential approach only including the second modality in positive reads of the first modality. It did not matter which modality was assessed first. This strategy for lymph node assessment resulted in a sensitivity, specificity, PPV and NPV of 83.3%, 95.6%, 62.5%, and 98.5%, respectively. After correction for received treatment and human papillomavirus status, primary tumour (P = 0.009) or lymph node (P < 0.001) Hopkins score ≥4 on 18F-FDG-PET/CT remained significant predictors of RFS. CONCLUSION: For response evaluation of the primary tumour 18F-FDG-PET/CT only is the preferred strategy, whereas for the neck a sequential approach including both DWI and 18F-FDG-PET/CT resulted in the best diagnostic accuracy for follow-up after (chemo)radiotherapy. Qualitative analysis of 18F-FDG-PET/CT is a stronger predictor of RFS than DWI analysis.

The multilayered structure of the human corpus spongiosum.

PURPOSE: Urethral reconstruction is performed in patients with urethral strictures or for correction of congenital disorders. In the case of shortage of tissue, engineered tissue may enhance urethral reconstruction. As the corpus spongiosum (CS) is important in supporting the function of the urethra, tissue engineering of the urethra should be combined with reconstruction of a CS. For that purpose, detailed knowledge of the composition of the CS, more specifically its extracellular matrix (ECM) and vascularization is needed for scaffold design. The objective of this study is to analyze the microarchitecture of the CS through (immuno) histology and scanning electron microscopy (SEM). METHODS: The CS including the urethra of patients undergoing male-to-female genital confirming surgery was harvested. This CS was fixed and processed for either (immuno) histology or for SEM. RESULTS: Four layers could be distinguished in the CS; first a transition zone from urethra epithelium to a collagen rich layer, which was highly vascularized, followed by a second, elastin rich layer. The third layer was formed by veins, arteries and vascular spaces and the last layer showed the transition from this vascular rich region to the collagen rich tunica albuginea. In this layer collagen bundles intertwined with elastic fibres. In the CS different components of the ECM were visible and distinguishable. CONCLUSION: This study provides novel and detailed information on the microarchitecture of the CS and the distribution of vascularization, which is important for scaffold design in tissue engineering.

Retinal dysplasia mimicking intraocular tumor: MR imaging findings with histopathologic correlation.

We report a 6-month-old boy who presented with unilateral leukocoria, retinal detachment, and a retrolental mass in a microphthalmic eye based on retinal dysplasia with concurrent optic nerve aplasia. Dysplastic retinal tissue, a rare congenital defect, may create a clinical and radiologic picture of an intraocular mass closely resembling tumor tissue. MR imaging findings with histopathologic correlation are presented to facilitate discrimination of the more common causes of leukocoria.

Activation of Rho-dependent cell spreading and focal adhesion biogenesis by the v-Crk adaptor protein.

The small GTPase RhoA plays a critical role in signaling pathways activated by serum-derived factors, such as lysophosphatidic acid (LPA), including the formation of stress fibers in fibroblasts and neurite retraction and rounding of soma in neuronal cells. Previously, we have shown that ectopic expression of v-Crk, an SH2/SH3 domain-containing adapter proteins, in PC12 cells potentiates nerve growth factor (NGF)-induced neurite outgrowth and promotes the survival of cells when NGF is withdrawn. In the present study we show that, when cultured in 15% serum or lysophosphatidic acid-containing medium, the majority of v-Crk-expressing PC12 cells (v-CrkPC12 cells) display a flattened phenotype with broad lamellipodia and are refractory to NGF-induced neurite outgrowth unless serum is withdrawn. v-Crk-mediated cell flattening is inhibited by treatment of cells with C3 toxin or by mutation in the Crk SH2 or SH3 domain. Transient cotransfection of 293T cells with expression plasmids for p160ROCK (Rho-associated coiled-coil-containing kinase) and v-Crk, but not SH2 or SH3 mutants of v-Crk, results in hyperactivation of p160ROCK. Moreover, the level of phosphatidylinositol-4,5-bisphosphate is increased in v-CrkPC12 cells compared to the levels in mutant v-Crk-expressing cells or wild-type cells, consistent with PI(4)P5 kinase being a downstream target for Rho. Expression of v-Crk in PC12 cells does not result in activation of Rac- or Cdc42-dependent kinases PAK and S6 kinase, demonstrating specificity for Rho. In contrast to native PC12 cells, in which focal adhesions and actin stress fibers are not observed, immunohistochemical analysis of v-CrkPC12 cells reveals focal adhesion complexes which are formed at the periphery of the cell and are connected to actin cables. The formation of focal adhesions correlates with a concomitant upregulation in the expression of focal adhesion proteins FAK, paxillin, alpha3-integrin, and a higher-molecular-weight form of beta1-integrin. Our results indicate that v-Crk activates the Rho-signaling pathway and serves as a scaffolding protein during the assembly of focal adhesions in PC12 cells.

Fatal aspiration of polyethylene glycol solution.

Endoscopy of the colon requires adequate cleansing of the entire bowel. Several laxative regimens have been propagated, but bowel preparation with polyethylene glycol (PEG) solution is popular because of the easy application and good cleansing results. Although very safe in daily use, complications of this bowel-cleansing procedure have been reported and aspiration of the PEG solution is a possible and serious hazard. A case report is presented of a patient who aspirated the PEG solution and ultimately died because of respiratory failure.

Direct diffusion of cis-diamminedichloroplatinum(II) in intraperitoneal rat tumors after intraperitoneal chemotherapy: a comparison with systemic chemotherapy.

Chemotherapy i.p. is increasingly being tested as a treatment modality for cancer limited to the peritoneal cavity. We have developed a rat tumor model in which penetration and distribution of cis-diamminedichloroplatinum(II) into intraperitoneal tumors have been studied. The platinum concentration in intraperitoneal tumor nodules, measured by two techniques, flameless atomic absorption spectroscopy and proton-induced X-ray emission, was always higher after i.p. treatment than i.v. Further, platinum concentrations were higher at the periphery of the tumor after i.p. administration than after i.v., while platinum concentrations in the center of the tumor nodules were identical. No difference was detected in platinum concentrations in s.c. tumors nor in the total area under the curve (plasma) after i.p. and i.v. administration of cis-diamminedichloroplatinum(II), suggesting that the higher drug concentration measured in peritoneal tumors after i.p. administration is due to direct diffusion of the drug from the peritoneal cavity.

3D Orbital Reconstruction in a Patient with Microphthalmos and a Large Orbital Cyst-A Case Report.

BACKGROUND: Orbital cysts are rare developmental anomalies that can occur in microphthalmic and anophthalmic patients. Such cysts can promote orbital growth and subsequently markedly increase the size of the orbit, which is commonly underdeveloped in these patients. Cyst removal is therefore generally dissuaded (at least) in the first 5 years. CLINICAL CASE: A 6-year-old boy with a microphthalmos and a cyst developed protrusion of his prosthetic eye and a swelling of the lower eyelid. MRI showed a large cyst causing distortion of the right orbit. Due to the expansive orbital growth and subsequent misfitting of the prosthesis, cystectomy and orbital floor reconstruction was performed using 3D technology. CONCLUSION: 3D imaging and printing enables exact delineation of orbital cysts and the adjacent bony structures. Furthermore it offers the possibility to plan an individual surgical approach and to design and fabricate a custom fit orbital floor implant.

The immunohistochemical localization of the non-specific lipid transfer protein (sterol carrier protein-2) in rat small intestine enterocytes.

A 13 kDa protein was isolated from rabbit small intestine brush-border membrane vesicles that was postulated to be involved in intestinal phosphatidylcholine (PC) and cholesterol uptake. This protein has cholesterol and PC-transfer activity in vitro (Turnhofer, H. et al. (1991) Biochim. Biophys. Acta 1064, 275-286) and has a molecular mass and isoelectric point similar to that of the non-specific lipid transfer protein (nsL-TP, identical to sterol carrier protein-2). In addition, the first 28 N-terminal amino acid residues of the 13 kDa protein are nearly identical to nsL-TP from different species (Lipka, G. et al. (1995) J. Biol. Chem. 270, 5917-5925). In view of its possible role in intestinal lipid absorption, the localization of nsL-TP in rat small intestine was investigated using immunohistochemistry and immunoblotting. It is shown that nsLTP is predominantly localized in a subapical zone of the enterocyte but not in the brush-border membrane, thereby excluding a role in lipid uptake of this protein at the level of the plasma membrane. nsL-TP co-localized with the peroxisomal marker PMP70, underscoring earlier observations that nsL-TP is a peroxisomal protein. nsL-TP was found to be present along the entire length of the small intestine. The 58 kDa cross-reactive protein that was recently identified as a peroxisomal thiolase was shown to be present only in a small segment approximately halfway down the jejunum. The close apposition of the peroxisomes with the apical membrane and the discrete distribution of the 58 kDa protein may indicate that these organelles play a role in the intracellular processing of absorbed lipids.

Extended lymph node dissection for gastric cancer: who may benefit? Final results of the randomized Dutch gastric cancer group trial.

PURPOSE: The extent of lymph node dissection appropriate for gastric cancer is still under debate. We have conducted a randomized trial to compare the results of a limited (D1) and extended (D2) lymph node dissection in terms of morbidity, mortality, long-term survival and cumulative risk of relapse. We have reviewed the results of our trial after follow-up of more than 10 years. PATIENTS AND METHODS: Between August 1989 and June 1993, 1,078 patients with gastric adenocarcinoma were randomly assigned to undergo a D1 or D2 lymph node dissection. Data were collected prospectively, and patients were followed for more than 10 years. RESULTS: A total of 711 patients (380 in the D1 group and 331 in the D2 group) were treated with curative intent. Morbidity (25% v 43%; P <.001) and mortality (4% v 10%; P =.004) were significantly higher in the D2 dissection group. After 11 years there is no overall difference in survival (30% v 35%; P =.53). Of all subgroups analyzed, only patients with N2 disease may benefit of a D2 dissection. The relative risk ratio for morbidity and mortality is significantly higher than one for D2 dissections, splenectomy, pancreatectomy, and age older than 70 years. CONCLUSION: Overall, extended lymph node dissection as defined in this study generated no long-term survival benefit. The associated higher postoperative mortality offsets its long-term effect in survival. For patients with N2 disease an extended lymph node dissection may offer cure, but it remains difficult to identify patients who have N2 disease. Morbidity and mortality are greatly influenced by the extent of lymph node dissection, pancreatectomy, splenectomy and age. Extended lymph node dissections may be of benefit if morbidity and mortality can be avoided.

On the limitation of 6-tioguaninenucleotide monitoring during tioguanine treatment.

BACKGROUND: Tioguanine (thioguanine) has been proposed as a rescue thiopurine for azathioprine or mercaptopurine intolerant inflammatory bowel disease patients. The use of tioguanine leads to high 6-tioguaninenucleotide (6-thioguaninenucleotide) levels in red blood cells but, contra-intuitively, these have yet not been associated with an increased risk of myelotoxicity. AIM: To assess the role of 6-tioguaninenucleotide concentrations in developing myelotoxicity during tioguanine treatment. METHODS: Database analysis of 25 patients treated with tioguanine. Clinical findings and laboratory parameters were related to 6-tioguaninenucleotide levels. RESULTS: One patient developed a myelodepression (21 mg TG/day for 3 months and 6-tioguaninenucleotide 714 pmol/8 x 10(8) red blood cells). 6-Tioguaninenucleotide levels varied greatly between individuals (mean 6-tioguaninenucleotide level 621 pmol/8 x 10(8) red blood cells, s.d. 340 pmol/8 x 10(8) red blood cells and range 34-1653 pmol/8 x 10(8) red blood cells). The TG dosages (mean 20.6 mg/day and median 20 mg/day) did not correlate with 6-tioguaninenucleotide levels (r = 0.31, N.S.). High 6-tioguaninenucleotide levels (>450 pmol/8 x 10(8) red blood cells) did not effect haemoglobin concentrations (mean 8 mmol/L), peripheral leucocyte (mean 7.5 x 10(9)/L) or platelet counts (mean 298 x 10(9)/L). No correlations were established between laboratory parameters, type of disease and 6-tioguaninenucleotide level. CONCLUSION: High 6-tioguaninenucleotide levels in erythrocytes (>450 pmol/8 x 10(8)) during TG treatment compared to azathioprine or mercaptopurine treatment are not indicative for (developing) myelotoxicity.

[Abscess formation due to lost stones during laparoscopic cholecystectomy]. / Abcesvorming door verloren stenen bij een laparoscopische cholecystectomie.

Two women aged 79 and 69 years presented with abdominal pain at 15 and 38 months respectively after a laparoscopic cholecystectomy. In both cases perforation of the gallbladder had occurred with spillage of bile and gallstones. A CT-scan carried out at presentation showed signs of an abdominal abscess. The origin of the abscess was initially unknown. The first patient was operated on immediately. In the second patient a drain was placed in the abscess under ultrasound guidance. During operation gallstones were seen in the abscess cavity in both patients. Both patients recovered well. Although perforation of the gallbladder with spillage of gallstones during laparoscopic cholecystectomy often occurs, the incidence of major postoperative complications is low. However, in some cases reoperation is necessary. Removal of all spilled stones is therefore indicated to prevent complications. If abdominal symptoms persist after laparoscopic cholecystectomy, an abscess due to spilled gallstones should be considered. Ultra-sound or CT are the most sensitive means of for tracing spilled gallstones or abscesses.

Quantitative diffusion-weighted MRI parameters and human papillomavirus status in oropharyngeal squamous cell carcinoma.

BACKGROUND AND PURPOSE: Patients with human papillomavirus-positive oropharyngeal squamous cell carcinomas have a better survival rate than those with human papillomavirus-negative oropharyngeal squamous cell carcinomas. DWI characterizes biologically relevant tumor features, and the generated ADC may also provide prognostic information. We explored whether human papillomavirus status and ADC values are independent tumor characteristics. MATERIALS AND METHODS: Forty-four patients with oropharyngeal squamous cell carcinomas underwent pretreatment DWI. ADC values for the primary tumors were determined by using 3 b-values in an ROI containing the largest area of solid tumor on a single section of an axial DWI image. Human papillomavirus status was determined with p16 immunostaining, followed by high-risk human papillomavirus DNA detection on the p16-positive cases. RESULTS: Twenty-two patients were human papillomavirus-positive (50.0%). ADC values were not significantly different between human papillomavirus-negative (ADC(mean) = 1.56 [1.18-2.18] × 10(3) mm(2)/s) and human papillomavirus-positive tumors (ADC(mean) = 1.46 [1.07-2.16] × 10(3) mm(2)/s). CONCLUSIONS: No significant association between ADC and human papillomavirus status was found in oropharyngeal squamous cell carcinomas. In our study population, differences in genetic and histologic features between human papillomavirus-positive and human papillomavirus-negative oropharyngeal squamous cell carcinomas did not translate into different ADC values. Long-term follow-up studies are needed to establish whether ADC has prognostic value and whether this is independent of the human papillomavirus status.

Detection of calcifications in retinoblastoma using gradient-echo MR imaging sequences: comparative study between in vivo MR imaging and ex vivo high-resolution CT.

BACKGROUND AND PURPOSE: Intratumoral calcifications are very important in the diagnosis of retinoblastoma. Although CT is considered superior in detecting calcification, its ionizing radiation, especially in patients with hereditary retinoblastoma, should be avoided. The purpose of our study was to validate T2*WI for the detection of calcification in retinoblastoma with ex vivo CT as the criterion standard. MATERIALS AND METHODS: Twenty-two consecutive patients with retinoblastoma (mean age, 21 months; range, 1-71 months) with enucleation as primary treatment were imaged at 1.5T by using a dedicated surface coil. Signal-intensity voids indicating calcification on T2*WI were compared with ex vivo high-resolution CT, and correlation was scored by 2 independent observers as poor, good, or excellent. Other parameters included the shape and location of the signal-intensity voids. In 5 tumors, susceptibility-weighted images were evaluated. RESULTS: All calcifications visible on high-resolution CT could be matched with signal-intensity voids on T2*WI, and correlation was scored as excellent in 17 (77%) and good in 5 (23%) eyes. In total, 93% (25/27) of the signal-intensity voids inside the tumor correlated with calcifications compared with none (0/8) of the signal-intensity voids outside the tumor. Areas of nodular signal-intensity voids correlated with calcifications in 92% (24/26), and linear signal-intensity voids correlated with hemorrhage in 67% (6/9) of cases. The correlation of signal-intensity voids on SWI was better in 4 of 5 tumors compared with T2*WI. CONCLUSIONS: Signal-intensity voids on in vivo T2*WI correlate well with calcifications on ex vivo high-resolution CT in retinoblastoma. Gradient-echo sequences may be helpful in the differential diagnosis of retinoblastoma. The combination of funduscopy, sonography, and high-resolution MR imaging with gradient-echo sequences should become the standard diagnostic approach for retinoblastoma.

Diffusion-weighted imaging of the head and neck in healthy subjects: reproducibility of ADC values in different MRI systems and repeat sessions.

BACKGROUND AND PURPOSE: DWI is typically performed with EPI sequences in single-center studies. The purpose of this study was to determine the reproducibility of ADC values in the head and neck region in healthy subjects. In addition, the reproducibility of ADC values in different tissues was assessed to identify the most suitable reference tissue. MATERIALS AND METHODS: We prospectively studied 7 healthy subjects, with EPI and TSE sequences, on 5 MR imaging systems at 3 time points in 2 institutions. ADC maps of EPI (with 2 b-values and 6 b-values) and TSE sequences were compared. Mean ADC values for different tissues (submandibular gland, sternocleidomastoid muscle, spinal cord, subdigastric lymph node, and tonsil) were used to evaluate intra- and intersubject, intersystem, and intersequence variability by using a linear mixed model. RESULTS: On 97% of images, a region of interest could be placed on the spinal cord, compared with 87% in the tonsil. ADC values derived from EPI-DWI with 2 b-values and calculated EPI-DWI with 2 b-values extracted from EPI-DWI with 6 b-values did not differ significantly. The standard error of ADC measurement was the smallest for the tonsil and spinal cord (standard error of measurement = 151.2 × 10(-6) mm/s(2) and 190.1 × 10(-6) mm/s(2), respectively). The intersystem difference for mean ADC values and the influence of the MR imaging system on ADC values among the subjects were statistically significant (P < .001). The mean difference among examinations was negligible (ie, <10 × 10(-6) mm/s(2)). CONCLUSIONS: In this study, the spinal cord was the most appropriate reference tissue and EPI-DWI with 6 b-values was the most reproducible sequence. ADC values were more precise if subjects were measured on the same MR imaging system and with the same sequence. ADC values differed significantly between MR imaging systems and sequences.