Neurologic complications in Wegener's granulomatosis

Nervous system involvement is relatively frequent in Wegener's granulomatosis (WG). It may be difficult to differentiate between the primary central nervous system involvement and complications secondary to concomitant arterial hypertension, renal insufficiency and iatrogenic effects of immunosuppressive therapy. The crucial role in the assessment of intracranial pathology may be ascribed to the diagnostic imaging techniques: magnetic resonance imaging (MRI), computed tomography (CT) and cerebral blood flow imaging utilising the single photon emission computed tomography (SPECT). SPECT may prove superior sensitivity to MRI. It may be especially useful in differentiating central nervous system involvement in WG with secondary changes of other origin.     

Osteotomy of the navicular bone in scaphoid malunion]

In scaphoid malunions corrective osteotomy and filling the gap of scaphoid waist with bone graft was carried out. Corrective osteotomy of malunion was needed in 2 cases among 43 waist reconstructions. The size of the gap was assessed intraoperatively by carpal stretch test. In both 2 cases bone healing, correction of scaphoid angle and pain relief was achieved.     

One-day core needle biopsy in a breast clinic: 4 years experience

Many attempts have been made to combine the high diagnostic accuracy and conclusive rate of core needle biopsy (CNB) with the speed of fine needle aspiration cytology in evaluation of solid breast lesions. Multiple hybrid techniques have been developed to achieve this. We describe a cohort of patients for whom we used a relatively new, accelerated method of CNB processing, allowing for a definitive diagnosis the same day. All patients visiting the Radboud University Nijmegen Medical Centre breast clinic during a 4-year period were reviewed to identify all CNBs in this period performed in a same-day diagnosis track. CNB result was compared to post-operative pathology reports when available, and to follow-up when patients were not surgically treated. 1,060 patients underwent CNB of 1,383 lesions, 898 of which in a same-day diagnosis track with a sensitivity of 96.9 % and a specificity of 99.4 %. The inconclusive rate was 9.2 %. For a same-day diagnosis for solid breast lesions, we could give a conclusive diagnosis with accelerated CNB processing in 65 % of our patients requiring CNB. This technique can be used reliably in a same-day diagnosis breast clinic with a very high sensitivity, specificity, and conclusive rate.     

Primitive neuroectodermal tumor of rare localization in two members of one family

A 26-year-old man with primitive neuroectodermal tumour (PNET) is reported. The tumour originated from the cervical spinal cord and was resected partially. Few months later dissemination of the tumour to the meninges occurred. Familial history revealed that the first daughter of the patient had died in age of 14 months three years earlier of a tumour of the right cerebral hemisphere, also diagnosed as PNET.     

Malignant schwannoma of parotid gland. Case report and review of literature

The authors described a rare malignant neoplasm of peripheral nerve sheath, sarcomatous neurillemoma, localized in parotid gland in 72-year female. Findings of the computer tomography, nuclear magnetic resonance and Doppler-ultrasound are presented and discussed. A review of world literature, including 14 cases of this tumor, was made.     

New methods for using computer-aided detection information for the detection of lung nodules on chest radiographs

Objective:

To investigate two new methods of using computer-aided detection (CAD) system information for the detection of lung nodules on chest radiographs. We evaluated an interactive CAD application and an independent combination of radiologists and CAD scores.

Methods:

300 posteroanterior and lateral digital chest radiographs were selected, including 111 with a solitary pulmonary nodule (average diameter, 16 mm). Both nodule and control cases were verified by CT. Six radiologists and six residents reviewed the chest radiographs without CAD and with CAD (ClearRead +Detect™ 5.2; Riverain Technologies, Miamisburg, OH) in two reading sessions. The CAD system was used in an interactive manner; CAD marks, accompanied by a score of suspicion, remained hidden unless the location was queried by the radiologist. Jackknife alternative free response receiver operating characteristics multireader multicase analysis was used to measure detection performance. Area under the curve (AUC) and partial AUC (pAUC) between a specificity of 80% and 100% served as the measure for detection performance. We also evaluated the results of a weighted combination of CAD scores and reader scores, at the location of reader findings.

Results:

AUC for the observers without CAD was 0.824. No significant improvement was seen with interactive use of CAD (AUC = 0.834; p = 0.15). Independent combination significantly improved detection performance (AUC = 0.834; p = 0.006). pAUCs without and with interactive CAD were similar (0.128), but improved with independent combination (0.137).

Conclusion:

Interactive CAD did not improve reader performance for the detection of lung nodules on chest radiographs. Independent combination of reader and CAD scores improved the detection performance of lung nodules.

Advances in knowledge:

(1) Interactive use of currently available CAD software did not improve the radiologists'' detection performance of lung nodules on chest radiographs. (2) Independently combining the interpretations of the radiologist and the CAD system improved detection of lung nodules on chest radiographs.Chest radiography can be considered the workhorse of the radiology department. It is being used for the detection and diagnosis of multiple diseases, including lung nodules, which may represent early lung cancer. Since a chest radiograph is a two-dimensional image, overprojection of multiple anatomical structures is inevitable. This so-called anatomical noise substantially impedes interpretation of chest radiographs. Multiple studies have shown that a substantial amount of lung cancers are missed, ranging from 19% to 26%,^1,2 and even up to 90%.^3–5 More recent studies have shown that the problem of missing lung nodules is still present with the most modern digital radiographic technology.^6,7 Abnormalities can be missed as a result of inadequate search, perception errors or interpretation errors. It has been stated that interpretation by the radiologist is the most important factor for missing lung cancer on chest radiographs.^8,9To reduce miss rates, computer-aided detection (CAD) systems have been developed. Thus far, all studies dealing with chest radiography apply CAD as a second reader to the radiologist, meaning that the CAD marks are made available only after the radiologist has made a primary review. It remains the reader''s discretion to accept or disregard the CAD marks. Results of these studies were contradictory: some found an increased accuracy for the detection of lung nodules,^10–12 whereas other studies reported an increase in sensitivity only at the expense of loss in specificity.^13–16 One problem ameliorating the potential of CAD is the radiologist''s limited ability to reliably discriminate between true-positive (TP) and false-positive (FP) CAD marks.We therefore decided to explore alternative methods of using CAD information. First, we used CAD interactively. In the interactive mode, CAD marks remained hidden unless the radiologist queried a position in the image by clicking with the mouse on that location. If a CAD mark was present in this location, it was shown to the radiologist together with a score of suspicion. Such an interactive CAD system had been shown to be beneficial in chest radiography in an observer study that only used non-radiologists.¹⁷ Second, we computed a mathematical combination of reader and CAD scores. With this method, observers did not need to view the CAD marks at all during their reading of the images, but a mathematical combination of the reader and the CAD scores was computed afterwards. Both methods have been reported to outperform the use of CAD as a second reader for lesion detection in mammograms.^18–20The purpose of this observer study was to test the impact of these two alternative methods of using CAD information on nodule detection on chest radiographs. To optimize baseline performance without CAD, digitally bone-suppressed images (BSIs) were added to the original chest radiographs. BSIs have been shown to improve accuracy for the detection of focal lesions on chest radiographs;^21–24 a further increase in detection performance beyond that of BSIs by adding CAD has also been documented.²⁵     

Standalone computer-aided detection compared to radiologists�� performance for the detection of mammographic masses

Objectives

We developed a computer-aided detection (CAD) system aimed at decision support for detection of malignant masses and architectural distortions in mammograms. The effect of this system on radiologists' performance depends strongly on its standalone performance. The purpose of this study was to compare the standalone performance of this CAD system to that of radiologists.

Methods

In a retrospective study, nine certified screening radiologists and three residents read 200 digital screening mammograms without the use of CAD. Performances of the individual readers and of CAD were computed as the true-positive fraction (TPF) at a false-positive fraction of 0.05 and 0.2. Differences were analysed using an independent one-sample t-test.

Results

At a false-positive fraction of 0.05, the performance of CAD (TPF?=?0.487) was similar to that of the certified screening radiologists (TPF?=?0.518, P?=?0.17). At a false-positive fraction of 0.2, CAD performance (TPF?=?0.620) was significantly lower than the radiologist performance (TPF?=?0.736, P <0.001). Compared to the residents, CAD performance was similar for all false-positive fractions.

Conclusions

The sensitivity of CAD at a high specificity was comparable to that of human readers. These results show potential for CAD to be used as an independent reader in breast cancer screening.

Key points

? Computer-aided detection (CAD) systems are used to detect malignant masses in mammograms ? Current CAD systems operate at low specificity to avoid perceptual oversight ? A CAD system has been developed that operates at high specificity ? The performance of the CAD system is approaching that of trained radiologists ? CAD has the potential to be an independent reader in screening