Acute ureteric calculus obstruction: unenhanced spiral CT versus HASTE MR urography and abdominal radiograph.

The aim of this study is to compare the performance of unenhanced spiral CT to the combination of HASTE MR urography (MRU) and plain abdominal radiography (KUB) in patients suspected of having acute calculus ureteric obstruction. 64 patients with suspected acute calculus ureteric obstruction were evaluated. The presence of perirenal fluid, presence and level of ureteric obstruction and calculi were assessed on both techniques. 44 of 64 (69%) patients had acute calculus ureteric obstruction based on clinical, radiographic or surgical findings. MRU showed perirenal fluid in acute ureteric obstruction (77%) with a greater sensitivity than CT showed stranding (45%). The combination of fluid and ureteric dilation on MRU showed a sensitivity of 93% (CT 80%), specificity of 95% (CT 85%), and accuracy of 94% (CT 81%). There were 61 findings of either fluid or ureteric dilatation on MRU in 44 acutely obstructed kidneys compared with 37 similar findings on CT (p<0.005). Although there was excellent reproducibility (Kappa=/>0.75) in the finding of perirenal fluid on MRU, there was only fair interobserver agreement (Kappa<0.4) regarding perirenal stranding on CT. MRU/KUB showed ureteric calculi in 21/29 (72%) of patients with calculi seen by CT. Overall, MRU/KUB revealed 2.4 abnormalities per acutely obstructed ureter compared with 1.8 abnormalities detected by CT. MRU/KUB using HASTE sequences can diagnose the presence of acute calculus ureteric obstruction with similar accuracy to spiral CT. The technique has less observer variability and is more accurate than CT in detecting evidence of obstruction such as perirenal fluid.

The diagnostic utility of HASTE MRI in the evaluation of acute cholecystitis. Half-Fourier acquisition single-shot turbo SE.

PURPOSE: The purpose of this study was twofold: (a) to determine the significance of high signal intensity surrounding the gallbladder as seen on T2-weighted HASTE (half-Fourier acquisition single shot turbo SE) MR images in patients with acute cholecystitis and (b) to determine the sensitivity of T2-weighted HASTE MR images in detecting gallbladder and common bile duct (CBD) calculi in patients with acute cholecystitis. METHOD: Seventy-two patients with a suspicion of acute cholecystitis were referred for HASTE MRI over a 2 year period. Forty-one patients underwent MRI after sonography and the remaining 31 patients before sonography. MR images were independently evaluated for the presence of MR pericholecystic high signal and gallbladder and CBD calculi. Findings were correlated with results obtained at sonography and at surgery. RESULTS: Of the 72 patients imaged with HASTE MRI, 55 had cholecystitis based on clinical, sonographic, and/or surgical findings. Of these, 45 had acute and 10 had chronic cholecystitis. HASTE MRI demonstrated MR pericholecystic high signal in 41 of 45 (91%) of the patients with acute cholecystitis. The sensitivity of HASTE MRI in diagnosing acute cholecystitis was 91%. The specificity was 79%. The positive predictive value was 87%, the negative predictive value was 85%, and the overall accuracy of the test was 89%. Gallbladder stones were seen by HASTE MRI in 38 of 41 (93%) of patients with acute calculus cholecystitis demonstrated at sonography. CBD stones were demonstrated by HASTE MRI in seven of nine (78%) patients and by sonography in five of nine (56%) patients with documented choledocholithiasis on conventional cholangiography. CONCLUSION: HASTE MRI has a high degree of accuracy in diagnosing acute cholecystitis based on the single finding of pericholecystic MR high signal. A similar level of accuracy is demonstrated in detecting gallbladder stones. Biliary duct calculi are detected with even greater accuracy than with sonography in patients with acute cholecystitis. Invasive preoperative endoscopic retrograde cholangiography may therefore be limited to only those patients with acute cholecystitis and CBD stones demonstrated on HASTE MRI. These features make HASTE MRI and ideal imaging modality in the initial evaluation of acute biliary pain and may ultimately replace sonography in the preoperative evaluation of acute cholecystitis.

Fast MR imaging and the detection of small-bowel obstruction.

OBJECTIVE: Our aim was to determine whether fast MR imaging using the half-Fourier acquisition single-shot turbo spin-echo (HASTE) MR sequence is accurate for diagnosis of small-bowel obstruction. MATERIALS AND METHODS: Forty-three nonconsecutive patients with suspected small-bowel obstruction were evaluated with HASTE MR imaging during a 12-month period. Images were retrospectively assessed for the presence, level, and cause of bowel obstruction. Data were compared with results of conventional radiography and findings at surgery when available. RESULTS: Of the 43 patients imaged, 29 patients had small-bowel obstruction revealed by unenhanced or contrast-enhanced radiography or by CT. Surgical confirmation was available in 21 patients. Small-bowel obstruction was shown by HASTE MR imaging in 26 (90%) of these 29 patients. HASTE MR images showed the correct level of obstruction in 19 (73%) of the 26 patients and showed the cause of obstruction in 13 (50%) of the 26 patients. CONCLUSION: With a high degree of accuracy, HASTE MR imaging can show the presence and level of small-bowel obstruction.

MR urography using HASTE imaging in the assessment of ureteric obstruction.

OBJECTIVE: The purpose of this study was to evaluate an MR sequence using half-Fourier acquisition single-shot turbo spin-echo (HASTE) imaging in the assessment of ureteric obstruction. SUBJECTS AND METHODS: We prospectively evaluated 111 kidneys in 56 consecutive patients with HASTE MR urography and compared that imaging technique with excretory urography. The HASTE sequence was used to acquire images in the axial, sagittal, and coronal planes while patients held their breath. Level of obstruction and ureteric diameter were assessed, and the time required to determine the level of obstruction by both techniques was noted. RESULTS: With HASTE MR urography, we correctly diagnosed obstruction in 41 (100%) of 41 kidneys. Of the obstructed kidneys in which the ureter was shown by both excretory urography and MR urography, agreement was high (kappa = .642) between the two imaging techniques regarding the level of obstruction. HASTE MR urography showed perirenal fluid in 20 (87%) of 23 acutely obstructed kidneys. HASTE MR urography showed the site of obstruction on the first 13-sec scan in 33 (80%) of 41 kidneys. CONCLUSION: HASTE MR urography accurately and rapidly shows the level and degree of ureteric obstruction. It can be used to differentiate between acute and chronic obstruction on the basis of its ability to show perirenal fluid.

Emphysematous pyelitis and emphysematous pyelonephritis characterized by computerized tomography.

We report three cases of emphysematous pyelonephritis, all of them associated with perinephric emphysema, and one case of emphysematous pyelitis to demonstrate the value of computerized tomography (CT) in both diagnosis and patient management. The differentiation between air in the collecting system (emphysematous pyelitis), air within the parenchyma (emphysematous pyelonephritis), and air in the perinephric space (perinephric emphysema) may have significant prognostic (survival) and therapeutic (medical vs surgical) implications. Computerized tomography is currently the best method for demonstrating intrarenal air and for characterizing the location of that air (intracalyceal, intraparenchymal, perinephric, or pararenal).

A simple radiologic method to estimate the quantity of bowel gas.

Patients with functional bowel disorders frequently complain of bloating and abdominal pain, but no practical method is available to measure intestinal gas objectively. To evaluate a new technique, we evaluated 54 abdominal radiographs from 19 patients. A gastroenterologist and a radiologist independently outlined the intestinal gas bubbles in these films. Areas of gas bubbles were measured with a computer digitizing board. Bowel gas was also measured in 24 healthy controls, and in five emergency room patients, supine and erect radiographs were compared to evaluate the effects of position on bowel gas patterns. The two evaluators agreed well on the measured areas of bowel gas (r = 0.96), showing that this is a reliable method. Bowel gas was significantly greater in patients than in controls but did not correlate with symptoms. Bowel gas was significantly greater in supine than upright films, showing that the position of the patient must be standardized.

Hepatic infarction in preeclampsia.

Two cases of hepatic infarction in toxemia of pregnancy are described. Both patients had associated laboratory findings of the HELLP syndrome (hemolytic anemia, elevated liver enzyme levels, and low platelet levels). Computed tomography (CT) showed nonenhancing low-attenuation areas varying in configuration from peripheral, well-defined, wedge-shaped lesions to larger abnormalities. Magnetic resonance imaging showed a corresponding area of low signal intensity on T1-weighted images with high signal intensity on T2-weighted images. Ultrasound showed several well-defined peripheral hypoechoic areas. The low attenuation and lack of enhancement on CT scans and the absence of mass effect are the key distinguishing features.

Gastric and splenic infarction: a complication of intraarterial vasopressin infusion.

Gastric and splenic infarction following intraarterial infusion of vasopressin in a patient's left gastric artery is reported. None of the previously described factors predisposing to infarction were present and the cause appears to have been hyperconstriction of vessels in response to vasopressin. Computed tomography (CT) scanning was used to confirm the extent of involvement.

Comparison of intrapulmonary, percutaneous intrathoracic, and subcutaneous models for the propagation of human pulmonary and nonpulmonary cancer cell lines in athymic nude mice.

The propagation efficiencies, growth patterns, histological appearances, and roentgenographic demonstration of tumors derived from six continuous human pulmonary tumor cell lines implanted intrathoracically (i.t.) and intrabronchially (i.b.) were compared with the conventional s.c. implantation method at three different tumor cell inocula (N = 184, i.b.; N = 185, i.t.; N = 180, s.c.). A tumor-related mortality of 100% was noted when the six different human lung tumor cell lines, including A549 adenocarcinoma, NCI-H125 adenosquamous carcinoma, NCI-H460 large cell undifferentiated carcinoma, NCI-H69 small cell carcinoma, and NCI-H358 and NCI-H322 bronchioloalveolar cell carcinomas, were implanted i.b. at a 1.0 x 10(6) tumor cell inoculum. A similar (92%) tumor-related mortality was observed when these same lung tumor cell lines were implanted i.t. at a 1.0 x 10(6) tumor cell inoculum (P greater than 0.10), whereas minimal (5%) tumor-related mortality was noted when cells from the six different cell lines were implanted s.c. (P less than 0.001). In addition, a dose-dependent, tumor-related mortality was noted for either i.t. or i.b. implantation when lower (1.0 x 10(5) or 1.0 x 10(4] tumor cell inocula were employed. Histological characteristics and growth patterns of tumors propagated employing the three implantation techniques were closely comparable for all three propagation methods and, in all instances, histological appearances of the tumors were representative of the current tumor cell lines from which they were derived. Approximately 30% of the lung tumors propagated i.t. grew in the chest wall and/or in the lung parenchyma as well as in the pleural space. In contrast, tumors propagated i.b. grew predominantly in the lung parenchyma. When five nonpulmonary human tumor cell lines (including U251 glioblastoma, LOX amelamontic melanoma, HT-29 colon adenocarcinoma, OVCAR 3 ovarian adenocarcinoma, and adriamycin-resistant MCF-7 breast adenocarcinoma) were propagated i.b. or i.t., there was considerable site-specific variability in tumor-related mortality depending on the tumor type. These data demonstrate that both the i.b. and i.t. models should be useful for the in vivo propagation and study of certain human pulmonary and nonpulmonary carcinomas as well as being advantageous for future studies of cancer biology and developmental therapeutics.

Novel intrapulmonary model for orthotopic propagation of human lung cancers in athymic nude mice.

A major impediment to the study of human lung cancer pathophysiology, as well as to the discovery and development of new specific antitumor agents for the treatment of lung cancer, has been the lack of appropriate experimental animal models. This paper describes a new model for the propagation of human lung tumor cells in the bronchioalveolar regions of the right lungs of athymic NCr-nu/nu mice via an intrabronchial (i.b.) implantation procedure. Over 1000 i.b. implantations have been performed to date, each requiring 3 to 5 min for completion and having a surgery-related mortality of approximately 5%. The model was used successfully for the orthotopic propagation of four established human lung cancer cell lines including: an adenosquamous cell carcinoma (NCI-H125); an adenocarcinoma (A549); a large cell undifferentiated carcinoma (NCI-H460), and a bronchioloalveolar cell carcinoma (NCI-H358). When each of the four cell lines was implanted i.b. using a 1.0 X 10(6) tumor cell inoculum, 100 +/- 0% (SD) tumor-related mortality was observed within 9 to 61 days. In contrast, when the conventional s.c. method for implantation was used at the same tumor cell inoculum, only minimal (2.5 +/- 5%) tumor-related mortality was observed within 140 days (P less than 0.001). Similarly, when a 1.0 X 10(5) or 1.0 X 10(4) cell inoculum was used, a dose-dependent, tumor-related mortality was observed when cells were implanted i.b. (56 +/- 24% or 25 +/- 17%) as compared with the s.c. method (5 +/- 5.7% or 0.0 +/- 0%) (P less than 0.02 and P less than 0.05, respectively). Most (greater than 90%) of the lung tumors propagated by i.b. implantation were localized to the right lung fields as documented by necropsy and/or high-resolution chest roentgenography techniques which were developed for these studies. The intrapulmonary model was also used for establishment and propagation of xenografts derived directly from enzymatically digested, fresh human lung tumor specimens obtained at the time of diagnostic thoracotomy and representing all four major lung cancer cell types as well as a bronchioloalveolar cell carcinoma. Approximately 35% (10 of 29) of the fresh primary human lung tumor specimens and 66% (2 of 3) of tumors metastatic to the lung were successfully propagated i.b. at a 1.0 X 10(6) tumor cell inoculum, whereas only 20% (1 of 5) of the specimens were successfully grown in vivo via the s.c. route from a 1.0 X 10(7) tumor cell inoculum.(ABSTRACT TRUNCATED AT 400 WORDS)

Sonographic findings in adenomyosis of the uterus.

In an attempt to define better the sonographic findings of adenomyosis of the uterus, we reviewed sonograms in seven cases of pathologically proven extensive adenomyosis without associated uterine diseases. In all cases, the uterus was enlarged. In five cases, the posterior wall of the uterus was thickened, and echoes in the endometrial cavity were eccentric. Six cases showed a slight decrease in uterine echogenicity. One case had sonographic findings suggestive of a calcified leiomyoma. The diagnosis of adenomyosis cannot be made conclusively by sonography. However, it can be suggested if the uterus is slightly enlarged and if the posterior portion of the myometrium is anechoic and thickened.

Brown tumor in secondary hyperparathyroidism causing acute paraplegia.

The first known case of a "brown tumor" associated with secondary hyperparathyroidism causing paraplegia is described. A 69-year-old white woman with chronic renal failure due to hypertension was admitted for back pain, and while she was under observation, paraplegia developed. A complete block was demonstrated by myelography. Computed tomography confirmed a mass at the level of obstruction, and results of biopsy were consistent with "brown tumor." Neurologic symptoms were markedly improved with high-dose corticosteroids and a debulking procedure. This entity is important to recognize because prompt treatment of the hyperparathyroidism or decompression of the tumor mass by surgical means or corticosteroid administration can provide marked improvement in symptoms.

Primary Wegener's granulomatosis of the trachea: radiologic manifestations.

This is the third reported case of Wegener's granulomatosis of the trachea occurring as the primary initial event in a young patient. Roentgenographic findings consisted of a 3 cm intraluminal mass with extensive tracheal narrowing. In a young patient with inspiratory stridor, a mass causing narrowing of the trachea, and a course complicated by symptoms of vasculitis, the possibility of Wegener's granulomatosis should be considered.

CT demonstration of pharyngeal narrowing in adult obstructive sleep apnea.

Sleep apnea is a major cause of daytime hypersomnolence. Among the proposed etiologies, focal obstruction of the airways at the level of the pharynx has been suggested but not proven. Using computed tomography, the cross-sectional area of the airway can be readily assessed. Thirty-three adults with clinically proven sleep apnea and 12 normal adults underwent systematic computed tomography of the neck. Significant airway narrowing was demonstrated in all the patients with obstructive sleep apnea, whereas no such narrowing was seen in the controls. In 11, the narrowing was at a single level, whereas in 22 patients two or more levels were affected. This study has shown that a structurally abnormal airway may serve as an anatomic substrate for the development of sleep apnea. On the basis of this evidence, uvulopalatopharyngoplasty has been performed in two patients with relief of symptoms in one.

Computerized tomography in obstructive sleep apnea. Correlation of airway size with physiology during sleep and wakefulness.

Pathophysiologic changes during sleep in patients with obstructive apnea are often associated with alterations in upper airway function during awake periods. To determine whether these functional changes are related to abnormal airway structure, we performed computerized tomography (CT) in 20 awake patients with obstructive apnea and in 10 control subjects. The CT scan measurements of cross-sectional areas of the nasopharynx, oropharynx, and hypopharynx in apneic patients were significantly reduced (p less than 0.05) compared with those in the control subjects. Sites of obstruction varied, and apparent airway occlusion occurred in 6 patients. Reduced pharyngeal size correlated with increased sleep-disordered breathing rates (p less than 0.05), more severe nocturnal oxygen desaturation (p less than 0.05), and the presence of a saw-tooth pattern of flow-volume curves obtained during awake periods (p less than 0.05). Structural upper airway narrowing is detectable with CT in awake patients with obstructive sleep apnea.

Transverse colon volvulus: diagnosis and treatment.

Although considered rare, transverse colon volvulus (TCV) may actually comprise as many as 10% of all cases of colon volvulus. Correct identification clinically is necessary in order to reduce the high mortality. Unlike the treatment of sigmoid volvulus, conservative treatment of TCV is thought to be inadequate. Furthermore, simple proximal colostomy may lead to bowel necrosis. Bowel resection, rather than detorsion procedures, is advocated. The barium or diatrizoate enema examination can readily differentiate TCV from sigmoid and cecal volvulus if one pays careful attention to detail.

CT patterns of mesenteric disease.

To evaluate the patterns of mesenteric disease as visualized by computed tomography (CT), we reviewed the scans of 370 patients whose primary diagnoses coincided with diseases known from the pathology literature to have frequent mesenteric involvement. Diagnoses included selected malignancies, inflammatory diseases, and traumatic injuries. Four general patterns of involvement of the mesentery were recognized: (a) rounded masses, (b) "cake-like" masses, (c) ill-defined masses, and (d) stellate mesentery. Of the malignancies reviewed, mesenteric involvement as visualized by CT occurred most commonly with ovarian carcinoma (20/52) and non-Hodgkin's lymphoma (41/134). The incidences of CT evidence of involvement of the mesentery with other common malignancies were carcinoma of the colon (8/68), carcinoma of the pancreas (5/21), and leukemia (5/19). Certain benign and malignant lesions of the mesentery do demonstrate unique CT patterns of involvement. Examples of the individual patterns in common and unusual disease states are illustrated.