A L Baert

Localized 1H NMR spectroscopy in fifty cases of newly diagnosed intracranial tumors

Fifty patients with newly diagnosed, untreated intracranial tumors were examined with 1H nuclear magnetic resonance single-volume spectroscopy (MRS) using a 1.5 T whole-body MR system. Prior to the MRS, contrast enhanced MR and/or CT imaging studies were carried out. Histological verification was obtained in all patients except one. All tumor spectra revealed distinct abnormalities as compared with the normal brain spectra. Although most meningiomas showed a rather characteristic spectral pattern, generally features specific for the various tumor types were not observed. For instance, though a strong lactic acid signal was seen in most malignant tumors, this signal was also evident in five benign neoplasms.

CT and MRI of ruptured intracranial dermoids

SummaryTwo patients with ruptured intracranial dermoids, examined with both CT and MRI are reported. Clinical presentation was transient cerebral ischemia in one patient and acute meningeal signs in the other. CT scan showed typical fat density of the tumor and the subarachnoid space. On MRI both the tumor and the subarachnoid fat, were strongly hyperintense on T1-weighted images.

Catheter-directed lysis of iliofemoral vein thrombosis with use of rt-PA

Abstract The aim of our study was to evaluate the results of catheter-directed thrombolysis and complementary procedures to treat acute iliofemoral deep vein thrombosis (DVT). A total of 24 consecutive patients with acute iliofemoral DVT underwent intrathrombus drip infusion of alteplase (3 mg/h; mean dosage 86 mg, range 45–174 mg), while intravenous heparin (1000 U/h) was continued. Complementary procedures were hydrodynamic thrombectomy in 3 and primary insertion of a Wallstent in 9 patients. Patency of 19 thrombosed veins (79 %) was restored with prompt symptomatic relief. An underlying anatomical anomaly or lesion was present in 13 patients: iliac vein compression syndrome (n = 8), absent (n = 2) or obstructed (n = 1) vena cava or venous stenosis (n = 2). Ten of the abnormalities were unknown before lysis and eight were relieved by stent deployment. Puncture site bleeding was the only complication but led to transfusion in 6 patients (25 %). Symptomatic reocclusion occurred in 4 patients. Catheter thrombolysis of iliofemoral vein thrombosis revealed many anatomical abnormalities which may predispose to thrombosis and are often amenable to stenting.

Percutaneous transluminal renal angioplasty: initial results and long-term follow-up in 202 patients.

Percutaneous transluminal renal angioplasty was performed in 202 patients with 250 stenoses. The procedure was successful in 201 of 250 (83%). Results were better for postostial atherosclerotic lesions (94%), fibromuscular lesions (83%), and transplant kidneys (71%) than for ostial atherosclerotic lesions (29%). Of all the patients, 61% had reduced blood pressures following the procedure, with cure (diastolic blood pressure ≤90 mm Hg) in 31% of the patients. Cure rate with a mean follow-up of 25.8±19.4 months was 21% in bilateral atheromatous lesions, 30% in unilateral atheromatosis, 65% in unilateral fibromuscular disease, and 40% in bilateral fibromuscular dysplasia. Of the transplanted patients, 60% were cured. Complications occurred in 23 (11%) of the patients. Recurrence of stenoses occurred in 16 lesions (8%). 80% within the first year after the procedure.

Sonographic appearance of normal lymph nodes.

Normal lymph nodes appear sonographically as somewhat flattened hypoechogenic structures. Chronic inflammation, obesity, and degenerative changes leading to benign fatty replacement of lymphoid tissue are responsible for the variations seen with high‐resolution ultrasonography. These fatty deposits, beginning in the center of the lymph node and progressing toward the periphery, are easily recognized as highly reflective defects in the hypoechogenic lymphoid tissue.

Staging and follow-up of rheumatoid arthritis of the knee. Comparison of sonography, thermography, and clinical assessment.

Twenty patients with longstanding polyarticular rheumatoid arthritis (including knee involvement) were selected for this study. The severity of the knee synovitis was assessed before and during treatment (with intra‐articular corticosteroid injections) using clinical scores, sonography, and thermography. In all patients, the inflammation regressed during treatment. During follow‐up, the quantity of synovial fluid, as measured sonographically 10 days after the start of therapy, correlated best with the clinical status. Maximal regression of synovial thickening was noted on delayed sonograms performed three months after treatment. Thermographic peak temperature showed good correlation with the clinical status, but the thermographic index was unreliable.

Skip areas in hepatic steatosis: a sonographic-angiographic study

Abstract“Skip areas” in focal steatosis describes a newly proposed “subsegmental type” of focal steatosis, which differs in both extent and topography from the more classic “lobar or segmental type” of focal steatosis.In the subsegmental type of steatosis, fatty infiltration can be considered homogeneous through-out the liver, with the exception of small flattened portions of less affected parenchyma, called “ skip areas.” These regions are mainly located in the subcapsular areas or along the interlobar fissures or the gallbladder bed.Observations using ultrasound in vivo, as well as on postmortem in vitro angiograms, suggest that both the extent and topography of these skip areas can be explained by local differences in vascular anatomy.

Expiratory CT in cigarette smokers: correlation between areas of decreased lung attenuation, pulmonary function tests and smoking history

Abstract. The aim of this study was to determine the correlation between cigarette-smoke-related bronchial disease and air trapping as assessed by expiratory high-resolution CT (HRCT) scans. Thirty healthy subjects (11 non-smokers, 7 ex-smokers for > 2 years, 12 current smokers; age range 35–55 years) with a smoking history between 0 and 28.5 pack-years underwent pulmonary function tests (PFT) and HRCT in inspiration and expiration in supine and prone position. The extent of air trapping was scored in ventral and dorsal aspects of the upper, middle and lower lung portions. In 24 subjects (7 non-smokers, 7 ex-smokers, 10 current smokers) areas of focal air trapping were found, and were present significantly more often in dependent lung portions (p < 0.05) compared with non-dependent portions. No significant differences were found between apical and basal lung zones. Scores of focal air trapping were not significantly different between smokers and ex-smokers, but were significantly lower (p < 0.05) in non-smokers and showed a significant (p < 0.0005) correlation with pack-years. The degree of air trapping was also associated with several lung function tests, especially RV, DLCO, FRC, FEV1 and FEV1/VC. Air trapping is seen in smokers with normal PFT and correlates with the severity of the smoking history, independently of current smoking status.

Comparison of manganese biodistribution and MR contrast enhancement in rats after intravenous injection of MnDPDP and MnCl2

Purpose: To compare the time course of the MR enhancing properties and biodistri-bution of manganese (Mn) in rats given i.v. Mn dipyridoxyl diphosphate (MnDPDP) or Mn chloride (MnCl2). Material and Methods: Twenty-four adult rats were injected i.v. with 5 μmol/kg MnDPDP or MnCl2, or with 0.5 ml/kg saline. High resolution T1-weighted MR imaging was performed during early (10 min), mid (2 h) and late (24 h) phases after injection. Mn concentrations in major organs were measured by using an ICP-AES technique, and correlated with MR findings. Results: Variable degrees of signal enhancement of major organs observed in MR images corresponded with the amount of Mn uptake after injection of MnDPDP or MnCl2. A prominently lower cardiac, pancreatic and hepatic uptake of Mn was seen at 10 min in rats injected with MnDPDP compared with those given MnCl2 and this was reflected in a difference in signal intensity (SI) in the MR images. At 2 h, the Mn content and SI in the major organs were similar with both MnDPDP and MnCl2. An overall Mn clearance was achieved at 24 h without any important organ retention, with kidney excretion of Mn seen only with MnDPDP. Conclusion: With both MnDPDP and MnCl2, the Mn uptake correlates with the SI enhancement in tissues. The reduced initial cardiac uptake of Mn after MnDPDP treatment compared to MnCl2 may account for the favourable cardiovascular safety of the contrast agent. These data contribute to an understanding of SI enhancement by MnDPDP, and are consistent with other studies showing that at a dose of 5 μmol/kg, MnDPDP can be safely used as a potent MR organ-specific contrast agent.

Acute obstruction of the renal collecting system: the intrarenal resistive index is a useful yet time-dependent parameter for diagnosis.

Abstract. The aim of this study was to determine whether the intrarenal resistive index (RI) can be used for the diagnosis of acute obstruction in patients with renal colic and to determine whether the index is time-related. Seventy patients referred to the Emergency Department with acute renal colic and without known associated renal disease underwent duplex Doppler ultrasonography to determine the intrarenal RI at the symptomatic and asymptomatic side. The age range of the patients was 18–72 years. An RI greater than 0.68 and/or an interrenal difference in RI greater than 0.06 and/or an increase in RI of more than 11 % compared with the normal side proved reliable cut-off values to diagnose acute renal obstruction. In addition, time dependency of the increase in RI was noted. No significant differences were observed within the first 6 h after the onset of symptoms. From 6 to 48 h, however, the mean RI in the affected kidney (0.70 ± 0.06; mean ± SD) was significantly different from that in the normal kidney (0.59 ± 0.04) (P < 0.001). In the same period the mean difference in RI was 0.08–0.13 (P < 0.001). After 48 h the sensitivity of RI dropped substantially. It is concluded that renal duplex Doppler ultrasonography is useful for diagnosing acute renal obstruction between 6 and 48 h after the onset of symptoms.