Arnold C. Friedman

Bronchioloalveolar cell carcinoma: impact of histology on dominant CT pattern.

The authors set out to determine how histologic variability in bronchioloalveolar cell carcinoma impacts dominant radiographic patterns shown by computed tomography (CT). Thoracic CTs of all patients with pathologically confirmed bronchioloalveolar cell carcinoma diagnosed over a 36-month period were reviewed without knowledge of underlying histologic type. The dominant CT pattern was recorded as 1) air space consolidation; 2) focal nodule or mass; and 3) multicentric nodules or masses. Nodules and masses were further characterized according to borders, distribution, and associated findings, including spiculations and air bronchograms. Histology was independently reviewed. Twenty-seven patients, 16 women and 11 men, mean age 60 years, were diagnosed with bronchioloalveolar cell carcinoma. In 6 (22%) of the 27 cases, the histology was mucinous, with malignant goblet cells identified. Five (83%) of the six mucinous neoplasms manifested as air space consolidation and three (50%) of the six presented with multiple nodules, in which two had coexisting air space consolidation. Of the remaining 21 cases (78%) with nonmucinous histology, the primary malignant cells of origin included Clara cells (n = 8), tall columnar epithelial cells (n = 7) and alveolar type II pneumocytes (n = 6). Sclerosis was a dominant histologic feature in 14 (67%) of the 21 cases. Seventeen (81%) of the nonmucinous neoplasms presented as isolated nodules or masses and four (19%) presented as multiple nodules or masses. Of these four patients with multifocal disease and nonmucinous histology, multiple bronchioloalveolar adenomas accounted for multicentricity in two of the patients. Significant correlations included air space consolidation with mucinous histology (p = 0.001) and focal nodule or mass with nonmucinous histology (p = 0.001). At CT of bronchioloalveolar cell carcinoma, the patterns of air-space consolidation correlate with mucinous histology and isolated nodules or masses with nonmucinous histology. The pattern of multiple nodules or masses, however, did not correlate with histology. Coexisting bronchioloalveolar adenomas can contribute to apparent multicentric disease in patients with nonmucinous histology.

Comparison of the Accuracy of CT Volume Calculated by Circumscription to Prolate Ellipsoid Volume (Bidimensional Measurement Multiplied by Coronal Long Axis)

RATIONALE AND OBJECTIVES Tumor volume is one of the most important factors in evaluating the response to treatment of patients with cancer. The objective of this study was to compare computed tomographic (CT) volume calculation using a semiautomated circumscribing tracing tool (manual circumscription [MC]) to prolate ellipsoid volume calculation (PEVC; bidimensional measurement multiplied by coronal long axis) and determine which was more accurate and consistent. MATERIALS AND METHODS The study included six patients with nine neoplasms, six phantoms, and two radiologists. The neoplasms and phantoms of varying sizes and shapes were imaged using multidetector CT scanners, with slice thicknesses ranging from 0.5 to 3 mm. Measurements were performed using a TeraRecon 3D workstation. Each lesion and phantom was manually circumscribed, and its three dimensions were measured. The measurements were repeated 2 weeks later. RESULTS MC of the phantoms deviated from their true volumes by an average of 3.0 +/- 1%, whereas PEVC deviated by 10.1 +/- 3.99%. MC interobserver readings varied by 1.2 +/- 0.6% and PEVC by 4.8 +/- 3.3%. MC intraobserver readings varied by 1.95 +/- 1.75% and PEVC by 2.5 +/- 1.55%. Patient tumor volume predicted by MC and PEVC varied greatly; MC interobserver readings differed by 3.3 +/- 2.1% and PEVC by 20.1 +/- 10.6%. MC intraobserver readings varied by 2.5 +/- 1.9% and PEVC by 5.5 +/- 3.2%. Variability was greater for complex shapes than for simple shapes. Bidimensional analysis demonstrated an interobserver difference of 12.1 +/- 8.7% and an intraobserver difference of 5.05 +/- 3.3%. These results demonstrate large interobserver and intraobserver variability. Variability was greater for complex shapes than for simple shapes. CONCLUSION MC of neoplasms provided more accurate and consistent volume predictions than PEVC. More complicated shapes demonstrated the superiority of MC over PEVC.

Gastrografin versus dilute barium for colonic CT examination: a blind, randomized study

Fifty patients receiving oral contrast medium the day of their CT examinations were studied to evaluate colonic opacification. Two groups were given small volumes (20 versus 30 ml) of nondilute diatrizoate meglumine/diatrizoate sodium (Gastrografin) the night prior to examination and were compared with groups receiving no contrast medium (control) or a large volume (600 ml) of dilute barium the night prior to examination. Frequency of total colonic opacification was as follows: 30 ml Gastrografin. 92%; 20 ml Gastrografin. 71%; dilute barium. 46%; and control. 9%; Significant artifact was infrequent in all groups. Administration of small volumes of nondilute Gastrografin is a well tolerated, inexpensive, and effective method for opacifying the colon for CT.

Feasibility of Remote CT Colonography at Two Rural Native American Medical Centers

OBJECTIVE Fort Defiance Indian Hospital and Tuba City Regional Health Care Center are two rural hospitals with limited availability of optical colonoscopy (OC) and other methods of colorectal cancer screening. Our goals were to determine whether adequate examinations could be obtained with remote supervision after brief onsite instruction and to share lessons learned in our experience with a remote CT colonography (CTC) screening program. MATERIALS AND METHODS After brief onsite instruction, including performing a CTC examination on a volunteer to train the CT technologists, both sites began performing CTC using standard bowel preparation, fecal tagging, automatic insufflation, and low-dose technique. Studies were transferred to the University of Arizona Hospital for image quality assessment of stool, residual fluid, distention, and interpretation, with reports returned via the teleradiology information system. Clinical follow-up was performed on those patients referred for polypectomy or biopsy. RESULTS Three hundred twenty-one subjects underwent CTC, including 280 individuals referred for screening examinations (87%). Ninety-two percent of subjects (295/321) had acceptable amounts of residual stool, 91% (293/321) had acceptable levels of fluid, and 92% (294/321) had acceptable distention. Fourteen percent (44/321) of CTC patients had polyps 6 mm or larger in size, with a positive predictive value of 41% for those who subsequently underwent colonoscopy-polypectomy (11/27). CONCLUSIONS CTC can be introduced to rural underserved communities, performed locally, and interpreted remotely with satisfactory performance, thereby increasing colorectal cancer screening capacity. Important aspects of implementation should include technologist training, referring physician education, careful attention to image transmission, and clearly defined methods of communication with patients and referring providers.

MR Signal Intensity Calculations Are Not Reliable for Differentiating Renal Cell Carcinoma from Lipid Poor Angiomyolipoma

about 5% of all nodules ( 4 ). Therefore, to determine whether FNAB is indicated, we believe a complete clinical history, a physical examination, a serum thyrotropin measurement, and an analysis of the US features ( 5 ) are required. Unfortunately, the authors didn’t mention them. Additionally, malignant involvement is also frequent in nodules smaller than 10 mm; thus, an arbitrary diameter cutoff of 10 mm for cancer risk is not justifi ed ( 6 ). In other words, it would have been appropriate for the authors to evaluate nodules smaller than 10 mm according to US features. Furthermore, we don’t agree with the statement that “false-positive cytologic outcomes cannot be avoided in some cases.” False-positive results are usually owing to suspicious fi ndings. That is to say, the gray zones in cytologic reports are follicular neoplasms, Hürthle cell neoplasms, and cytologic fi ndings suggestive of but not diagnostic for papillary carcinoma ( 2 ). Therefore, standardization of terminology will improve patient care. Cytologic diagnoses should be organized into six categories—benign, atypia of undetermined signifi cance, neoplasm, suspicious for malignancy, malignant, and nondiagnostic—for the risks and the treatment or follow-up strategies are quite different for each ( 5 ).

The Fabella Sign: Fabella Displacement in Synovial Effusion and Popliteal Fossa Masses

Posterior displacement of the fabella is a reliable sign of synovial effusion or mass which may be applied even when inflammation or post-traumatic edema obscures the extrasynovial fat lines of the knee joint. The fabella normally moves posteriorly as the knee is flexed, but correlation of fabella position with degree of flexion defined ranges of normal and abnormal fabella position which are useful in diagnosis. If all lateral views are obtained with the knee flexed over a standard angle bolster, fabella position is standardized and fabella displacement readily detected without need for measurement. With experience, fabella displacement is readily apparent in non-standard positions as well. Normal fabella position does not rule out small effusion or effusion which is confined to the suprapatellar pouch because the knee is extended.

Differential density of normal renal parenchyma on nonenhanced CT: a new observation.

PURPOSE Nonenhanced CT scans through the kidneys commonly show a difference in radiopacity between the inner peripelvic portion of the renal parenchyma and the more peripheral regions of the renal parenchyma. This normal observation has not been described. METHOD We reviewed 50 nonenhanced CT scans. Renal parenchyma was evaluated by both visual inspection and density measurements of inner and outer aspects of the kidneys in 38 and visual inspection only in 12. A narrower window was used to better show density differences (100 W, 35 L). We recorded the indication for the CT, history, and recent blood chemistries. RESULTS The inner parenchyma was of greater radiopacity than the outer parenchyma in 35 of 50 cases by visual inspection and in all densitometry cases (38 of 38). There was no correlation with clinical history or blood chemistry. CONCLUSION A difference in density between the inner and outer portions of the renal parenchyma is very common and will often be seen if one looks for it. We have not shown an etiology for this difference, and indeed, it may be physiological. One must be aware of this finding to avoid mistaking it for pathology.

CT findings in venous intravasation complicating diverticulitis

A case of venous intravasation mimicking coloureteral fistula in a patient with sigmoid diverticulitis is reported. Venous intravasation is a rare but serious complication of barium examination of the colon.

Computer-Generated Holographic Stereograms

We examine one type of holographic stereogram and its implementation on two widely different media. The first medium is photoresist for a conventional computer-generated hologram. The second medium is photo-refractive polymer for re-writable holograms.

Hepatic excretion of urographic contrast medium: Use in delineating intrahepatic cholangiocarcinoma on scans delayed for 2 hours

Vicarious excretion of urographic contrast media by the liver has been detected by conventional radiographic methods in patients with renal impairment or unilateral obstruction. It occurs in patients with normal renal function, however, and can be detected by delayed postcontrast computed tomography scans. A case is presented in which an intrahepatic cholangiocarcinoma was best depicted on scans delayed for 2 hours. After 2 hours, the contrast medium remained within hepatic parenchyma but was virtually cleared from the vascular and interstitial spaces.