Aggressive leptomeningeal hemangioblastomatosis of the central nervous system in a patient with von Hippel-Lindau disease.

Hemangioblastomas of the central nervous system are the most common tumors seen in patients with von Hippel-Lindau (VHL) disease. A very rare case of diffuse leptomeningeal hemangioblastomatosis obliterating large areas of the subarachnoid space, both intracranial and within the spinal canal, which developed during a relatively short period, in a patient with VHL disease is presented.

Sacroiliac joints: anatomical variants on CT.

The purpose of this work was to examine the type and prevalence of anatomical variants of the sacroiliac joints (SJs) in patients without SJ disease on CT examinations. The study comprised 534 consecutive patients undergoing pelvic CT with various indications not related to diseases that could involve the SJ. Images printed on bone window settings were evaluated with reference to any deviation from the usual appearance of the SJ. Physical data and history of low back pain were recorded in each patient. Six types of anatomical variants were observed: accessory joints in 102 patients (19.1%), "iliosacral complex" in 31 (5.8%), bipartite iliac bony plate in 22 (4.1%), crescent-like iliac bony plate in 20 (3.7%), semicircular defects at the sacral or iliac side in 16 (3%), and ossification centers in 3 patients (0.6%). Accessory joints were more common in obese than in normal-weight individuals (p < 0.05) and in older than younger (<60 years) patients (p < 0.001) and presented degenerative alterations especially in patients with episodes of low back pain. Three of these variants (iliosacral complex, bipartite iliac bony plate, and crescent-like iliac bony plate) had higher incidence in women than in men (p < 0.05) and were not associated with degenerative changes. Knowledge of the normal variations in the SJ appearance broadens the understanding of SJ anatomy, facilitating image interpretation.

Variation in the appearance of the normal sacroiliac joint on pelvic CT.

OBJECTIVE: To describe the CT appearance of the ageing sacroiliac joints (SJ) and correlate the radiological findings with patients' gender, body mass index (BMI) and, in women, parity. MATERIALS AND METHODS: The study population included 288 consecutive patients who underwent pelvic CT for various indications not related to SJ diseases. Patients were stratified by age, BMI and parity in women. The joint space and subchondral sclerosis were assessed and the presence of osteophytes, ankylosis, erosions, subchondral cysts and vacuum phenomena were noted on bone window settings. RESULTS: The widths of the SJ space and of the subchondral sclerosis on the iliac and sacral sides were 2.3+/-0.4mm, 2.5+/-1.6mm and 1.4+/-0.5mm, respectively, in patients younger than 40 years of age and 1.9+/-0.2 mm, 3.6+/-2.1 mm and 2.3+/-1.1 mm, respectively, in patients older than 40 years of age. The joint space tends to become narrow and less uniform with advancing age, while subchondral sclerosis appeared to be wider and less uniform in the elderly. Osteophytes were present even in younger patients and their prevalence increased with advancing age. Ankylosis and erosions were rare findings, observed only after the fifth decade of life. A higher prevalence of asymmetric non-uniform SJ space, ill-defined, non-uniform, extensive subchondral sclerosis and ankylosis was observed in women, obese and multiparous mothers than the age matched men, normal weighted individuals and non-multiparous women, respectively. CONCLUSION: Conventional pelvic CT can provide valuable information concerning the SJ, when reviewed on bone window settings. The CT appearance of the SJ is closely related to patients age, gender, BMI and, in women, parity. Knowledge of the spectrum of radiological findings observed in the normal population may be useful when interpreting examinations of patients with SJ disease.

Primary ilio-psoas abscess extending to the thigh in a neonate: US, CT and MR findings.

Psoas abscess in children, and especially in neonates, is an uncommon condition which is difficult to diagnose clinically. The US, CT and MR findings of a psoas abscess in a neonate, which extended to the thigh, are reported. Imaging was helpful in revealing the abnormality, in demonstrating its extension and in determining its nature. The child was treated conservatively and the abscess resolved, leaving atrophy of the psoas muscle.

Excretory phase CT urography for opacification of the urinary collecting system.

OBJECTIVE: The purpose of our study was threefold: to evaluate the ability of excretory phase CT urography to opacify the urinary collecting system by comparing opacification seen on CT with the opacification seen on a series of unmatched IV urography examinations; to determine the optimal CT urography technique for ureteral filling by comparing studies of patients who were imaged supine, prone, and with abdominal compression; and to assess the possible value that reformatted planar images might add to axial excretory phase images. SUBJECTS AND METHODS: Seventy patients with hematuria were imaged in one of four ways. Twenty-five patients underwent contrast-enhanced excretory phase helical CT of the kidneys, ureters, and bladder. All patients were imaged in a supine position. Ten other patients underwent a similar CT protocol in which we used abdominal compression. Ten further patients underwent excretory phase CT while in a prone position. A final 25 patients underwent IV urography. Each patient's collecting system was arbitrarily divided into 10 parts (both right and left sides of calices; pelvis; upper, mid, and lower ureters) for scoring of images on a five-point scale for opacification by contrast material. Opacification scores for the four groups of patients were then compared. For patients who underwent CT, reformatted images of the collecting systems were generated and evaluated for their potential to add value to the conventional axial images. RESULTS: We found no significant difference in the ability of CT urography and IV urography to yield opacification of the calices, pelvis, and upper or mid ureters. Opacification of the distal ureter was less well seen on supine CT urography than on IV urography. Prone and compression CT urography resulted in better opacification of the collecting system than the supine noncompression technique. Opacification of the distal ureter was best seen with compression CT and was as good as that seen with IV urography. Reformatted CT urography was judged to be of probable or definite additional value to the axial images in 44% of cases. In each case, we saw a pathologic finding whose relationship to the kidney and collecting system was not as easy to appreciate on the axial CT scans. CONCLUSION: CT urography with abdominal compression results in reliable opacification of the collecting system that is comparable with opacification seen on IV urography. In patients with abnormalities, reformatted images were a useful adjunct to axial images. CT urography has potential as an imaging tool for the urothelium.

A comparison between digital fluoroscopic hard copies and 105-mm spot films in evaluating vesicoureteric reflux in children.

OBJECTIVE: To compare fluoroscopic freeze-frame digital images with conventional 105-mm spot films during voiding cystourethrography (VCUG) with regard to diagnostic quality and radiation dose. MATERIALS AND METHODS: VCUG was performed on 57 consecutive children by a commercially available fluoroscopic digital system. Both freeze-frame digital images and conventional 105-mm spot films were obtained during 90 s of fluoroscopy. Skin radiation dose was assessed separately for spot films and for both fluoroscopy and spot films, employing thermoluminescent crystals on the anterior surface of the body. Patients were classified into three age groups: group A younger than 12 months, group B 1-5 years old and group C 5-12 years of age. RESULTS: Digital and conventional images provided diagnostically identical results in 108 out of 114 ureters examined (94.7%). Percentage reductions in skin radiation dose due to the fluoroscopic hard copies compared with the four 105-mm radiographs were 53.8%, 50.5% and 57.1% for groups A, B and C, respectively. CONCLUSION: Substitution of conventional 105-mm spot films during VCUG with digital fluoroscopic hard copies resulted in a substantial reduction in radiation dose. Digital images were as accurate as the conventional films in excluding vesicoureteric reflux (VUR). The two methods correlated well in diagnosing and grading VUR.

Hepatodiaphragmatic interposition of the colon in the upright and supine position.

OBJECTIVE: Hepatodiaphragmatic interposition of the colon (HDIC) has been previously evaluated with chest radiography (CR) of patients examined in an erect position. In this work the presence of HDIC was assessed in patients who underwent CT in the supine position. MATERIALS AND METHODS: In 1,440 patients, 806 men and 634 women, 19-83 years old subjected to CR and abdominal CT for various indications, HDIC was retrospectively evaluated. RESULTS: In 2.4% of the patients HDIC was found using CT in the supine position but in only 0.3% on CR. The variation appeared more frequently in men than in women and in older adults and individuals with an increased amount of intraabdominal fat. This latter finding may represent an additional factor favoring malposition of the colon. CONCLUSION: The results of this study indicate that HDIC has a significantly greater incidence in the supine position of patients, and it can not be excluded on the basis of negative CR.