RSNA Centennial Article: Gone but Not Completely forgotten­ pictorial review of "antiquated" radiologic procedures [corrected].

The field of diagnostic and therapeutic radiology has always been characterized by constant innovation and creativity to evolve to its current form. There are numerous imaging techniques that were once prevalent but have become outdated and were replaced by the current examinations and modalities, which improve diagnostic accuracy and patient outcomes. Many of these outdated examinations were first described in the journal Radiology during its first 100 years of existence and were subsequently able to be disseminated across its vast readership to become the standard of care across the nation and the world. These earlier techniques, such as pneumoencephalography as it applies to neuroimaging and neurosurgery; kymography, a predecessor of cardiac imaging; contrast agents such as Thorotrast; and miscellaneous cultural tools, such as the shoe-fitting fluoroscope, left lasting impressions on the current practice of radiology and reflect a small subset of the imaging examinations of our predecessors. Knowledge of historic radiologic examinations and procedures is important to understand how we have arrived at the current practice of radiology we embrace today and how our field can continue to evolve to improve our diagnostic and therapeutic abilities to fit the changing needs of our patients.

Case report: benign gastric ulcer erosion leading to a gastropericardial fistula in a patient with no known risk factors.

A 53-year-old homeless male presented to the emergency department with sudden onset chest pain and was found to have a large pneumopericardium on chest X-ray. The patient had no history of surgery, hiatal hernia, or ulcer disease. A contrast-enhanced computed tomography scan demonstrated the pneumopericardium and raised concern for possible gastropericardial fistula from a benign gastric ulcer. An esophagogastroduodenoscopy confirmed the fistula, as did surgery, and intraoperatively vegetable particular matter was removed from the anatomic space continuous with the pericardium.

Computed tomographic diagnosis of appendicitis within a spigelian hernia.

A Spigelian hernia is a rare abdominal wall hernia diagnosed with ultrasonography or computed tomography. We report the first case of acute appendicitis within a Spigelian hernia diagnosed by computed tomography.

Computer-aided detection (CAD) of lung nodules in CT scans: radiologist performance and reading time with incremental CAD assistance.

OBJECTIVE: The diagnostic performance of radiologists using incremental CAD assistance for lung nodule detection on CT and their temporal variation in performance during CAD evaluation was assessed. METHODS: CAD was applied to 20 chest multidetector-row computed tomography (MDCT) scans containing 190 non-calcified > or =3-mm nodules. After free search, three radiologists independently evaluated a maximum of up to 50 CAD detections/patient. Multiple free-response ROC curves were generated for free search and successive CAD evaluation, by incrementally adding CAD detections one at a time to the radiologists' performance. RESULTS: The sensitivity for free search was 53% (range, 44%-59%) at 1.15 false positives (FP)/patient and increased with CAD to 69% (range, 59-82%) at 1.45 FP/patient. CAD evaluation initially resulted in a sharp rise in sensitivity of 14% with a minimal increase in FP over a time period of 100 s, followed by flattening of the sensitivity increase to only 2%. This transition resulted from a greater prevalence of true positive (TP) versus FP detections at early CAD evaluation and not by a temporal change in readers' performance. The time spent for TP (9.5 s +/- 4.5 s) and false negative (FN) (8.4 s +/- 6.7 s) detections was similar; FP decisions took two- to three-times longer (14.4 s +/- 8.7 s) than true negative (TN) decisions (4.7 s +/- 1.3 s). CONCLUSIONS: When CAD output is ordered by CAD score, an initial period of rapid performance improvement slows significantly over time because of non-uniformity in the distribution of TP CAD output and not to a changing reader performance over time.

Abnormal findings on routine upper GI series following laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: The use of postoperative upper GI series (UGIS) after laparoscopic Roux-en-Y gastric bypass (LRYGBP) varies among bariatric surgeons. The authors describe the findings and impact of UGIS after LRYGBP. METHODS: From July 2003 to January 2006, 487 patients undergoing primary LRYGBP at a single academic institution had a single-contrast Gastrografin UGIS performed on the first postoperative day, without complication. Patient and operative demographics were: mean age 43 years, mean BMI 47 kg/m2, female 84%, and laparoscopic 100%. RESULTS: Of the 487 patients, the UGIS revealed 14 (2.9%) major and 88 (15.2%) minor abnormalities. Among the major UGIS abnormalities, 6 (1.2%) demonstrated a gastrojejunal anastomotic (GJA) leak, 8 (1.4%) confirmed complete obstruction at the GJA, and 1 (0.2%) disclosed a communication with the bypassed stomach. For the minor UGIS abnormalities, 45 (9.2%) displayed significant delay in contrast passage through the GJA, 23 (5.0%) had evidence of dilated loops of small and/or large bowel, and 6 (1.2%) verified miscellaneous abnormal findings (malrotation, lower esophageal dysmotility, jejunal clots). Patients with UGIS abnormalities necessitated additional procedures, delayed oral intake and/or longer length of stay (LOS). CONCLUSIONS: UGIS on postoperative day 1 is a useful means of evaluating postoperative LRYGBP anatomy and influenced postoperative care.

Pulmonary nodules on multi-detector row CT scans: performance comparison of radiologists and computer-aided detection.

PURPOSE: To compare the performance of radiologists and of a computer-aided detection (CAD) algorithm for pulmonary nodule detection on thin-section thoracic computed tomographic (CT) scans. MATERIALS AND METHODS: The study was approved by the institutional review board. The requirement of informed consent was waived. Twenty outpatients (age range, 15-91 years; mean, 64 years) were examined with chest CT (multi-detector row scanner, four detector rows, 1.25-mm section thickness, and 0.6-mm interval) for pulmonary nodules. Three radiologists independently analyzed CT scans, recorded the locus of each nodule candidate, and assigned each a confidence score. A CAD algorithm with parameters chosen by using cross validation was applied to the 20 scans. The reference standard was established by two experienced thoracic radiologists in consensus, with blind review of all nodule candidates and free search for additional nodules at a dedicated workstation for three-dimensional image analysis. True-positive (TP) and false-positive (FP) results and confidence levels were used to generate free-response receiver operating characteristic (ROC) plots. Double-reading performance was determined on the basis of TP detections by either reader. RESULTS: The 20 scans showed 195 noncalcified nodules with a diameter of 3 mm or more (reference reading). Area under the alternative free-response ROC curve was 0.54, 0.48, 0.55, and 0.36 for CAD and readers 1-3, respectively. Differences between reader 3 and CAD and between readers 2 and 3 were significant (P < .05); those between CAD and readers 1 and 2 were not significant. Mean sensitivity for individual readings was 50% (range, 41%-60%); double reading resulted in increase to 63% (range, 56%-67%). With CAD used at a threshold allowing only three FP detections per CT scan, mean sensitivity was increased to 76% (range, 73%-78%). CAD complemented individual readers by detecting additional nodules more effectively than did a second reader; CAD-reader weighted kappa values were significantly lower than reader-reader weighted kappa values (Wilcoxon rank sum test, P < .05). CONCLUSION: With CAD used at a level allowing only three FP detections per CT scan, sensitivity was substantially higher than with conventional double reading.

Cisterna chyli at routine abdominal MR imaging: a normal anatomic structure in the retrocrural space.

The cisterna chyli, a dilated lymphatic sac in the retrocrural space, represents the origin of the thoracic duct. It is seen in approximately half of lymphangiographic studies and 20% of autopsies. Highly fluid-sensitive magnetic resonance (MR) imaging sequences such as single-shot rapid acquisition with refocused echoes, which are currently used in many abdominal MR imaging protocols, frequently result in the depiction of this structure. The cisterna chyli was evident on abdominal MR images acquired in 30 (15%) of 200 consecutive patients who underwent MR imaging at the authors' institution between February and June 2002. Its appearance varied from that of a thick tube to that of a thin tube, parallel or converging tubes, tortuous tubes, a sausage-shaped fluid collection, a focal collection, or a focal plexus. Radiologists who perform MR imaging should be familiar with the various possible appearances of this normal anatomic structure so as not to mistake it for a pathologic entity.

Simultanagnosia through the eyes of an artist.

An 87-year-old artist experienced a top-of-the-basilar-artery embolic stroke secondary to atrial fibrillation and manifested a visual agnosia. Prior to her stroke, she painted scenes solely from memory. During her stroke recovery, her serial drawings and paintings revealed selective attention to the left lower quadrant, with important aspects of the whole image "clipped," as if missing from her internal representation of the whole object. Years later, her artistic abilities returned with only minor differences from those prior to her stroke.

Local staging of pancreatic carcinoma with multi-detector row CT: use of curved planar reformations initial experience.

PURPOSE: To evaluate the utility of curved planar reformations compared with standard transverse images in the assessment of pancreatic tumors. MATERIALS AND METHODS: Forty-three patients suspected of having pancreatic tumors underwent contrast material-enhanced biphasic multi-detector row computed tomography (CT). Curved planar reformations were generated along the pancreatic duct, common bile duct, and major mesenteric vessels. Three blinded independent readers assessed the curved planar reformations and transverse images separately for the presence of tumor, resectability, and vascular involvement. The results were compared with those of a consensus panel who evaluated the curved planar reformations and transverse images together along with clinical data and surgical findings. RESULTS: Of 43 patients, 20 had pancreatic malignancies as judged by the consensus panel and proven at biopsy and/or clinical follow-up. For tumor detection, transverse images and curved planar reformations had an average sensitivity of 95.0% and 98.4% (P >.05), respectively, and an average specificity of 90.9% and 91.3% (P >.05), respectively. For tumor resectability, transverse images and curved planar reformations had an average sensitivity of 85.7% and 71.4% (P >.05), respectively, and an average specificity of 85.2% and 84.3% (P >.05), respectively. Average interpretation time was 6.4 minutes with transverse images and 4.1 minutes with curved planar reformations. CONCLUSION: Curved planar reformations are equivalent to transverse images in the detection of pancreatic tumors and determination of surgical resectability.