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The purpose of this review article is to familiarize radiologists with the recently revised Response Evaluation Criteria in Solid Tumours (RECIST), used in many anticancer drug trials to assess response and progression rate. The most important modifications are: a reduction in the maximum number of target lesions from ten to five, with a maximum of two per organ, with a longest diameter of at least 10 mm; in lymph nodes (LNs) the short axis rather than the long axis should be measured, with normal LN measuring <10 mm, non-target LN >or=10 mm but <15 mm and target LN >or=15 mm; osteolytic lesions with a soft tissue component and cystic tumours may serve as target lesions; an additional requirement for progressive disease (PD) of target lesions is not only a >or=20% increase in the sum of the longest diameter (SLD) from the nadir but also a >or=5 mm absolute increase in the SLD (the other response categories of target lesion are unchanged); PD of non-target lesions can only be applied if the increase in non-target lesions is representative of change in overall tumour burden; detailed imaging guidelines. Alternative response criteria in patients with hepatocellular carcinoma and gastrointestinal stromal tumours are discussed. [ABSTRACT FROM AUTHOR]

Purpose: The selection for either primary or interval cytoreductive surgery (CRS) in patients with epithelial ovarian cancer (EOC) is currently based on imaging techniques like computed tomography (CT), [ 18 F]fluorodeoxyglucose-positron emission tomography ([ 18 F]FDG-PET), diffusion-weighted magnetic resonance imaging (DW-MRI) and/or diagnostic laparoscopy, but these have limitations. Folate receptor (FR)-targeted PET/CT imaging, using [ 18 F]fluoro-PEG-folate, could improve preoperative assessment, potentially reducing unnecessary laparotomies. This paper presents the first experience with [ 18 F]fluoro-PEG-folate PET/CT imaging in advanced stage EOC, focusing on safety, tolerability, and feasibility for reflecting the extent of disease., Methods: Tolerability and safety were monitored after administration of the [ 18 F]fluoro-PEG-folate tracer by measurements of vital function parameters (blood pressure, heart rate, peripheral oxygen saturation, respiratory rate, and temperature). In addition, (serious) adverse events were recorded. Disease burden was quantified using the Peritoneal Cancer Index (PCI) score on preoperative [ 18 F]fluoro-PEG-folate PET/CT and during surgery. PCI scores were compared with intraoperative findings, considering histopathologic results as the gold standard. Tissue specimens were stained for FRα and FRβ. Relative uptake of the radiotracer by EOC lesions and other tissues was quantified using body weighted standardized uptake values (SUV)., Results: The study was terminated prematurely during the interim analysis after inclusion of eight patients of whom five had completed the study protocol. Although [ 18 F]fluoro-PEG-folate demonstrated safety, efficacy for tumor-specific imaging was limited. Despite clear FRα overexpression, low tracer uptake was observed in EOC lesions, contrasting with high uptake in healthy tissues, posing challenges in specificity and accurately assessing tumor burden., Conclusions: Overall, while [ 18 F]fluoro-PEG-folate was well-tolerated, its clinical utility in the preoperative assessment of the extent of disease in EOC was limited. This highlights the need for further research in developing targeted imaging agents for optimal detection of EOC metastases., Trial Registration: Clinicaltrials.gov, NCT05215496. Registered 31 January 2022., Competing Interests: Declaration of competing interest A.D. Windhorst is editor-in-chief of Nuclear Medicine & Biology and was not involved in the editorial review or the decision to publish this article. All other authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To define a safe treatment dose of ipilimumab (IPI) and nivolumab (NIVO) when applied in combination with percutaneous hepatic perfusion with melphalan (M-PHP) in metastatic uveal melanoma (mUM) patients (NCT04283890), primary objective was defining a safe treatment dose of IPI/NIVO plus M-PHP. Toxicity was assessed according to Common Terminology Criteria for Adverse Events version 4.03 (CTCAEv4.03). Secondary objective was response rate, PFS and OS., Materials and Methods: Patients between 18-75 years with confirmed measurable hepatic mUM according to RECIST 1.1 and WHO performance score 0-1 were included. Intravenous IPI was applied at 1 mg/kg while NIVO dose was increased from 1 mg/kg in cohort 1 to 3 mg/kg in cohort 2. Transarterial melphalan dose for M-PHP was 3 mg/kg (maximum of 220 mg) in both cohorts. Treatment duration was 12 weeks, consisting of four 3-weekly courses IPI/NIVO and two 6-weekly M-PHPs., Results: Seven patients were included with a median age of 63.6 years (range 50-74). Both dose levels were well tolerated without dose-limiting toxicities or deaths. Grade III/IV adverse events (AE) were observed in 2/3 patients in cohort 1 and in 3/4 patients in cohort 2, including Systemic Inflammatory Response Syndrome (SIRS), febrile neutropenia and cholecystitis. Grade I/II immune-related AEs occurred in all patients, including myositis, hypothyroidism, hepatitis and dermatitis. There were no dose-limiting toxicities. The safe IPI/NIVO dose was defined as IPI 1 mg/kg and NIVO 3 mg/kg. There was 1 complete response, 5 partial responses and 1 stable disease (3 ongoing responses with a median FU of 29.1 months)., Conclusion: Combining M-PHP with IPI/NIVO was safe in this small cohort of patients with mUM at a dose of IPI 1 mg/kg and NIVO 3 mg/kg., (© 2022. Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).)

Background: Renal cell carcinoma (RCC) can be complicated by a venous tumor thrombus (TT), of which the optimal management is unknown., Objectives: This study sought to assess the prevalence of TT in RCC, its current management, and its association with venous thromboembolism (VTE), arterial thromboembolism (ATE), major bleeding (MB), and mortality., Methods: Patients diagnosed with RCC between 2010 and 2019 in our hospital were included and followed from RCC diagnosis until 2 years after, or until an outcome of interest (VTE, ATE, and MB) or death occurred, depending on the analysis. Cumulative incidences were estimated with death as a competing risk. Cause-specific hazard models were used to identify predictors and the prognostic impact., Results: Of the 647 patients, 86 had a TT (prevalence 13.3%) at RCC diagnosis, of which 34 were limited to the renal vein, 37 were limited to the inferior vena cava below the diaphragm, and 15 extended above the diaphragm; 20 patients started therapeutic anticoagulation and 45 underwent thrombectomy with/without anticoagulation. During follow-up (median 24.0 [IQR: 7.0-24.0] months), 17 TT patients developed a VTE, 0 developed an ATE, and 11 developed MB. TT patients were more often diagnosed with VTE (adjusted HR: 6.61; 95% CI: 3.18-13.73) than non-TT patients, with increasing VTE risks in more proximal TT levels. TT patients receiving anticoagulation still developed VTE (HR: 0.56; 95% CI: 0.13-2.48), at the cost of more MB events (HR: 3.44; 95% CI: 0.95-12.42) compared with those without anticoagulation., Conclusions: Patients with RCC-associated TT were at high risk of developing VTE. Future studies should establish which of these patients benefit from anticoagulation therapy., Competing Interests: Dr Klok has received research grants from Bayer, Merck Sharpe & Dohme, the Netherlands Organisation for Health Research and Development, Actelion, the Dutch Heart Foundation, and the Dutch Thrombosis Association, all outside the submitted work. Dr Huisman has received unrestricted grant support from The Netherlands Organisation for Health Research and Development (ZonMW); and received unrestricted grant support and fees for presentations from Boehringer Ingelheim, Pfizer-BMS, Bayer Health Care, Aspen, and Daiichi Sankyo, all outside the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2022 The Authors.)

Background: While immune checkpoint inhibition (ICI) has revolutionized the treatment of metastatic cutaneous melanoma, no standard treatments are available for patients with metastatic uveal melanoma (UM). Several locoregional therapies are effective in the treatment of liver metastases, such as percutaneous hepatic perfusion with melphalan (M-PHP). The available literature suggests that treatment with ICI following locoregional treatment of liver UM metastases can result in clinical response. We hypothesize that combining M-PHP with ICI will lead to enhanced antigen presentation and increased immunomodulatory effect, improving control of both hepatic and extrahepatic disease., Methods: Open-label, single-center, phase Ib/randomized phase II trial, evaluating the safety and efficacy of the combination of M-PHP with ipilimumab (anti-CTLA-4 antibody) and nivolumab (anti-PD-1 antibody) in patients with unresectable hepatic metastases of UM in first-line treatment, with or without the limited extrahepatic disease. The primary objective is to determine the safety, toxicity, and efficacy of the combination regimen, defined by maximum tolerated dose (MTD) and progression-free survival (PFS) at 1 year. Secondary objectives include overall survival (OS) and overall response rate (ORR). A maximum of 88 patients will be treated in phase I and phase II combined. Baseline characteristics will be described with descriptive statistics (t-test, chi-square test). To study the association between risk factors and toxicity, a logistic regression model will be applied. PFS and OS will be summarized using Kaplan-Meier curves., Discussion: This is the first trial to evaluate this treatment combination by establishing the maximum tolerated dose and evaluating the efficacy of the combination treatment. M-PHP has shown to be a safe and effective treatment for UM patients with liver metastases and became the standard treatment option in our center. The combination of ICI with M-PHP is investigated in the currently described trial which might lead to a better treatment response both in and outside the liver., Trial Registration: This trial was registered in the US National Library of Medicine with identifier NCT04283890 . Registered as per February 2020 - Retrospectively registered. EudraCT registration number: 2018-004248-49. Local MREC registration number: NL60508.058.19., (© 2022. The Author(s).)

Background and Purpose: A GTV boost is suggested to result in higher complete response rates in rectal cancer patients, which is attractive for organ preservation. Fiducials may offer GTV position verification on (CB)CT, if the fiducial-GTV spatial relationship can be accurately defined on MRI. The study aim was to evaluate the MRI visibility of fiducials inserted in the rectum., Materials and Methods: We tested four fiducial types (two Visicoil types, Cook and Gold Anchor), inserted in five patients each. Four observers identified fiducial locations on two MRI exams per patient in two scenarios: without (scenario A) and with (scenario B) (CB)CT available. A fiducial was defined to be consistently identified if 3 out of 4 observers labeled that fiducial at the same position on MRI. Fiducial visibility was scored on an axial and sagittal T2-TSE sequence and a T1 3D GRE sequence., Results: Fiducial identification was poor in scenario A for all fiducial types. The Visicoil 0.75 and Gold Anchor were the most consistently identified fiducials in scenario B with 7 out of 9 and 8 out of 11 consistently identified fiducials in the first MRI exam and 2 out of 7 and 5 out of 10 in the second MRI exam, respectively. The consistently identified Visicoil 0.75 and Gold Anchor fiducials were best visible on the T1 3D GRE sequence., Conclusion: The Visicoil 0.75 and Gold Anchor fiducials were the most visible fiducials on MRI as they were most consistently identified. The use of a registered (CB)CT and a T1 3D GRE MRI sequence is recommended., (Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Human papilloma virus type 16 (HPV16)-induced gynecological cancers, in particular cervical cancers, are found in many women worldwide. The HPV16 encoded oncoproteins E6 and E7 are tumor-specific targets for the adaptive immune system permitting the development of an HPV16-synthetic long peptide (SLP) vaccine with an excellent treatment profile in animal models. Here, we determined the toxicity, safety, immunogenicity and efficacy of the HPV16 SLP vaccine in patients with advanced or recurrent HPV16-induced gynecological carcinoma., Methods: Patients with HPV16-positive advanced or recurrent gynecological carcinoma (n = 20) were subcutaneously vaccinated with an HPV16-SLP vaccine consisting of a mix of 13 HPV16 E6 and HPV16 E7 overlapping long peptides in Montanide ISA-51 adjuvant. The primary endpoints were safety, toxicity and tumor regression as determined by RECIST. In addition, the vaccine-induced T-cell response was assessed by proliferation and associated cytokine production as well as IFNγ-ELISPOT., Results: No systemic toxicity beyond CTCAE grade II was observed. In a few patients transient flu-like symptoms were observed. In 9 out of 16 tested patients vaccine-induced HPV16-specific proliferative responses were detected which were associated with the production of IFNγ, TNFα, IL-5 and/or IL-10. ELISPOT analysis revealed a vaccine-induced immune response in 11 of the 13 tested patients. The capacity to respond to the vaccine was positively correlated to the patient's immune status as reflected by their response to common recall antigens at the start of the trial. Median survival was 12.6 ± 9.1 months. No regression of tumors was observed among the 12 evaluable patients. Nineteen patients died of progressive disease., Conclusions: The HPV16-SLP vaccine was well tolerated and induced a broad IFNγ-associated T-cell response in patients with advanced or recurrent HPV16-induced gynecological carcinoma but neither induced tumor regression nor prevented progressive disease. We, therefore, plan to use this vaccine in combination with chemotherapy and immunomodulation.

Background: To compare the median overall survival of patients with isolated nonresectable liver metastases in comparable groups of patients treated with either isolated hepatic perfusion (IHP) with melphalan or systemic chemotherapy., Patients and Methods: Colorectal cancer patients with isolated liver metastases, who underwent IHP, were included in this study. The control group consisted of a subgroup of colorectal cancer patients with liver metastases only, who were enrolled in the randomized CApecitabine, IRinotecan, Oxaliplatin (CAIRO) phase III study., Results: Ninety-nine patients were treated with IHP, and 111 patients were included in the control group. All patient characteristics were comparable except for age. Median follow-up was 78.1 months for IHP versus 54.7 months in the control group. Median overall survival was 25.0 [95% confidence interval (CI) 19.4-30.6] months for IHP and 21.7 (95% CI 19.6-23.8) months for systemic treatment and did not differ significantly (P = 0.29). Treatment-related mortality was 2% for the systemic treatment and 6% for IHP (P = 0.11)., Conclusion: Compared with a patient group with comparable characteristics treated with systemic chemotherapy, IHP does not provide a benefit in overall survival in patients with isolated nonresectable colorectal liver metastases. Currently, the use of IHP cannot be advocated outside the scope of clinical studies.

Purpose: The liver is one of the most common sites for metastatic solid tumors. If the liver is the only site of metastatic disease, regional treatment options can offer the benefit of high local exposure with limited systemic toxicity, especially for patients without (further) systemic treatment options. We report the results of our experience with isolated hepatic perfusion (IHP) in patients with isolated liver metastases from a variety of primary tumors., Patients and Methods: Nineteen patients with isolated unresectable liver metastases from a variety of tumors (13 uveal melanomas, 2 neuroendocrine carcinomas, 2 gastrointestinal stromal tumors, 1 hepatocellular carcinoma, and 1 high-grade sarcoma) were treated with a 60-min IHP using 200 mg melphalan. Patients were monitored for toxicity, response according to response evaluation criteria in solid tumors (RECIST) criteria, and survival., Results: One melanoma patient was not perfused due to insufficient isolation of the liver. There was no treatment-related mortality. Reversible grade 3 or 4 hepatoxicity occurred in 10 (56%) patients, while veno-occlusive disease occurred in 4 (22%) patients. Of the 12 uveal melanoma patients who were perfused, 4 (33%) patients had a partial hepatic response, 6 (50%) patients had stable hepatic disease, and 2 (17%) patients were immediately progressive. Median disease-free survival was 6.6 months with a median overall survival of 10.0 months. Fifty percent of other primary tumors showed at least partial remission, including one complete remission in a high-grade sarcoma patient., Conclusion: IHP with melphalan shows activity in patients with liver metastases from a variety of primary tumors, but other or additional drugs may improve therapeutic outcome.

Background: The aim of this study was to identify prognostic factors for local and systemic failure after isolated hepatic perfusion (IHP) with 200 mg melphalan in patients with colorectal liver metastases., Patients and Methods: Hundred and fifty-four patients were selected for IHP and underwent laparotomy. Patients were monitored for response, toxicity and survival. Univariate and multivariate analyses were carried out to identify prognostic factors for hepatic response and progression-free and overall survival., Results: Hepatic response rate was 50% with a median progression-free and overall survival of, respectively, 7.4 and 24.8 months. In multivariate analyses, absence of ability to perfuse through the hepatic artery (P = 0.003), severe postoperative complications (P = 0.048) and >10 liver metastases (P = 0.006) adversely influenced overall survival and no adjuvant chemotherapy adversely influenced progression-free survival., Conclusion: This is the first study to report prognostic factors for survival after IHP. Possibly, overall and disease-free survival can increase if preoperative screening is improved. In future studies on IHP, adjuvant chemotherapy should be considered.

Isolated hepatic perfusion (IHP) offers the advantage of high local drug exposure with limited systemic toxicity. To increase local drug exposure, we administered melphalan at a reduced flow in the hepatic artery during IHP (hepatic artery infusion, hepatic artery-portal vein perfusion, HI-HPP). Between December 2001 and December 2004, 30 patients with colorectal cancer liver metastases underwent HI-HPP with 200mg melphalan. Samples of the perfusate were taken for pharmacokinetic analysis. Patients were monitored for response, toxicity and survival. Perfusion was aborted prematurely in 2 patients due to leakage. During melphalan administration in the hepatic inflow cannula a mean flow rate of 121.3 mL/min and mean pressure of 62.5mm Hg were achieved. One patient died within 30 days after HI-HPP. Four patients developed veno-occlusive disease (VOD), while 2 patients showed signs of VOD. Twelve patients showed hepatic response, with a median duration of response of 11.5 months, according to WHO criteria. Although HI-HPP results in high perfusate melphalan concentration levels, it is associated with a relatively high level of hepatotoxicity and a limited response rate. We believe that the low flow and pressure rates found in this study can result in reduced drug penetration of the tumour and thus limited tumour response.

Patient and staff dose during CT guided coagulation of osteoid osteoma, tissue biopsy and abscess drainage were evaluated retrospectively on a conventional CT scanner and prospectively on a scanner equipped with fluoroscopic CT. The computed tomography dose index (CTDI) and the individual dose equivalent, i.e. the penetrating dose for workers at a depth of 10 mm tissue, were measured. Evaluation of CTDI enabled effective dose and maximum skin entrance doses for the patient to be determined. Doses were assessed for 96 CT guided interventions, including 16 drainages with average effective doses of 13.5 mSv and 9.3 mSv for the conventional CT scanner and the scanner with spiral CT fluoroscopy, respectively, 49 biopsies (effective doses of 8 mSv and 6.1 mSv, respectively), and 31 coagulations of osteoid osteoma (effective doses of 2.1 mSv and 0.8 mSv, respectively). Effective doses to patients were in the same range as those observed for regular diagnostic CT examinations. Entrance skin doses were well below the 2 Gy threshold for deterministic skin effects on the CT scanner equipped with fluoroscopic function (0.03-0.33 Gy), whilst skin doses on the conventional scanner were considerably higher (0.09-1.61 Gy). This is mainly owing to the fact that on the conventional scanner mAs was rarely reduced for scans evaluating needle position whereas low mAs per rotation was selected on the scanner with the fluoroscopy option. The maximum dose to a worker measured outside the lead apron was 28 microSv for one single procedure. The mean dose per procedure was below 10 microSv for radiologists and below 1 microSv for radiographers. Correcting for attenuation of the lead apron, the doses to workers are very low.

Purpose: To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions., Materials and Methods: In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients., Results: Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P <. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P <.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases., Conclusion: Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.

The spleen-liver model, as a predictor for contrast-to-noise ratio (C/N) in liver metastases, was verified for seven sequences in 22 patients with 70 colorectal metastases. Optimization of conventional spin-echo, T1-magnetization-prepared gradient-echo and fat frequency-selective presaturation inversion-recovery fast spin echo can be done using the spleen-liver model. C/N of liver-spleen and liver-metastases, however, differed significantly on our T1 gradient-echo and T2-weighted fast spin-echo images, with and without fat-selective saturation.

Purpose: To compare respiratory-triggered inversion-recovery (IR) gradient- and spin-echo (GRASE) magnetic resonance (MR) imaging with respiratory-triggered T2-weighted fast spin-echo (SE) imaging in the diagnosis of liver metastases., Materials and Methods: In this prospective study, two radiologists independently identified focal hepatic lesions on respiratory-triggered IR GRASE and respiratory-triggered fast SE MR images in 28 consecutive patients with 186 (135 malignant and 51 benign) proved lesions. A combination of findings at surgery, intraoperative ultrasonography (US), and histologic examination served as the standard of reference. Contrast-to-noise ratios (CNRs) were obtained from 86 lesions larger than 10 mm., Results: The sensitivity in the detection of liver metastases was, independent of lesion size and observer, higher for IR GRASE imaging (55%) than for fast SE imaging (44%-50%) (observer 1, P = .014; observer 2, P = .21). Confidence levels with IR GRASE imaging were higher, but not significantly so, than those with fast SE imaging (P < .098). Both observers characterized liver lesions better with IR GRASE than with fast SE imaging (observer 1, P = .04; observer 2, P = .48). The metastasis-liver CNR was significantly higher (P = .012) with IR GRASE imaging., Conclusion: The respiratory-triggered IR GRASE sequence is a fast alternative to the respiratory-triggered fast SE sequence in the evaluation of suspected liver metastases.

The aim of this study was to test the influence of observer experience on the accuracy for interpreting helical CT for acute pulmonary embolism (PE) and to identify sources of observer errors. Three observers of different expertise blindly assessed 147 helical CT scans for suspected PE (true status regarding absence or presence of PE known from independent reference studies). These observers were (a) an experienced CT radiologist, (b) a fellow in CT, and (c) a second-year resident without any formal training in CT. None of them had prior experience with CT for PE. Firstly, 70 CT scans were scored without revealing true PE status. Afterwards, feedback was provided and another 77 CT scans were evaluated. The CT scans were scored on a 5-point confidence scale and receiver-operator-characteristic analysis was performed. Different sources of interpretation errors were analyzed. The two observers with CT experience were significantly more accurate than the unexperienced observer. Their performance was not influenced by feedback training. Certain observer errors were identified, but there was no clear difference among the three observers considering the type of errors. There is significant influence of observer experience on accuracy of reading helical CT for PE: A basic working experience with whole-body CT seems to be a prerequisite. These results suggest that with this experience any radiologist should be able to achieve good accuracy; helical CT thus might become a suitable technique for acute PE in routine clinical practice.

Study Design: The early and late development of the neurocentral junction between the vertebral arch and the vertebral body was studied, and this structure was related to spinal surgery., Objectives: Because of its strategic position within the vertebral body, its structure could be of relevance for spinal surgery. During the positioning of cannulated pedicle screws and before penetration into the cancellous bone of the vertebral body, resistance had to be overcome inside the "pedicle" of the vertebral arch. Was this point of resistance related to the neurocentral joint?, Summary of Background Data: Data on the fate of this developmental structure after age 3-6 years, the age at which it fuses, appeared to be missing in literature., Methods: We examined dry bone and "fresh" vertebrae from individuals ranging in age from 0 to 75 years. Observations were recorded by means of gross anatomic photographs, micrographs, radiographs, and computed tomography scans., Results: After fusion of the junction at age 3-6 years, its structure persists through life as a bilateral plate of bone extending from the cranial to the caudal anular epiphyses inside the dorsolateral parts of the definitive body., Conclusions: This plate may function as a support for pedicle screw fixation. Its form explains typical burst fractures of the vertebral body. Spondylolysis at this site is unknown.

Nitrogen-containing bisphosphonates (NCBs) are potent inhibitors of bone resorption and are used in the treatment of adults with various skeletal disorders. Little is known about their effects on the growing skeleton. The authors retrospectively studied the skeletal radiographs obtained in nine children before, during, and after NCB administration. Bandlike metaphyseal sclerosis and concentric epi- and apophyseal sclerosis developed in all patients. The extent of sclerosis depended on the duration of treatment and was related to local, and probably general, skeletal growth activity. In the maturing spine, NCBs caused a "picture-frame" or "bone-within-bone" appearance, depending on continuation or cessation of administration. In addition, metaphyseal undertubulation of long bones was noted in five patients. After discontinuation of bisphosphonate treatment and/or closure of the growth plates, the degree of sclerosis decreased, and sclerosis tended to disappear, indicating that this is a reversible phenomenon.

Four patients with paravertebral extension of advanced tuberculous intervertebral disk-space infection were studied by CT and MRI. In one patient gadolinium-DTPA (Gd-DTPA) was administered intravenously as a paramagnetic contrast agent. MRI showed the disk-space abnormalities and extension of the inflammatory process to best advantage in the coronal plane. This plane demonstrated in one image the spinal localization and the paravertebral extension of the inflammation. Gd-DTPA assisted in delineating the communication of the vertebral and paravertebral components of inflammation. This phenomenon introduces an additional diagnostic element into the evaluation of spondylitis. Although the features of advanced tuberculous spondylitis are conspicuously well shown with MRI, further experience is needed to evaluate the potential of MRI in detecting early tuberculous spondylitis in relation to nontuberculous spondylitis.

This is an overview of the current applications of magnetic resonance imaging (MRI) in the genitourinary tract based on the experience with the 0.5-Tesla MR scanner (Gyroscan, Philips) at the Leiden University Hospital and on reports in the literature. MRI appears to share some of the limitations of CT. MRI cannot reliably differentiate between a malignant and a benign tumor. In the staging of ovarian malignancies by means of MRI, bowel preparation would be desirable. On the other hand, the soft-tissue contrast resolution of MRI is superior to that of CT and images can be obtained in any plane. Thus MRI promises to be an accurate method for staging malignancies. The results in the examination of transplant kidneys are encouraging. We expect that there will be a place for MRI as a complementary technique to ultrasonography in the diagnosis of scrotal disease.