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Papers by Gary Ghahremani

Radiologic Clinics of North America

Perforation of the alimentary tract may occur spontaneously in various gastrointestinal diseases ... more Perforation of the alimentary tract may occur spontaneously in various gastrointestinal diseases or develop due to an ingested foreign body, iatrogenic complication, and blunt or penetrating injuries. The detection of extraluminal air on radiographs of the chest or abdomen is often the initial clue to the diagnosis. It may not, however, be visible when the perforation is small, rapidly sealed, or well contained. Further evaluation by special radiographic techniques, gastrointestinal studies using contrast media, or CT examination can demonstrate the site and nature of the perforation. This article reviews the clinical features and methods for radiologic assessment of suspected perforations involving the upper gastrointestinal tract, small bowel, or colon and rectum.

Radiology, 1989

Topographic relationships among the gallbladder, liver, hepatic flexure of the colon, right hemid... more Topographic relationships among the gallbladder, liver, hepatic flexure of the colon, right hemidiaphragm, and anterolateral peritoneal reflection were evaluated with computed tomography in 75 patients with biopsy-proved cirrhosis and in 200 control subjects to determine the effect of cirrhotic liver morphology on the anatomy of the right upper quadrant of the abdomen. Interposition of the colon between the liver and anterolateral abdominal wall and/or diaphragm was seen in 18 of the 75 (24%) cirrhotic patients and in six of the 200 (3%) control subjects. There was a strong correlation among gallbladder malposition, colonic interposition, and a ratio of transverse caudate lobe width to right lobe width (C/RL) exceeding 0.60. Patients with cirrhosis, colonic interposition, and gallbladder malposition had a mean C/RL of 0.62, compared with a mean of 0.50 for cirrhotic patients without interposition (P less than .0001). The mean C/RL for control subjects without interposition was 0.43, as compared with 0.69 for control subjects with interposition (P less than .01). These acquired malpositions of the colon and gallbladder may pose a diagnostic dilemma and increase the risk of inadvertent injury during percutaneous liver biopsy, interventional biliary tract procedures, and laparotomy.

Textbook of Gastrointestinal Radiology, 2008

Endoscopy, 1992

The transmural granulomatous inflammation of chronic nature which characterizes the Crohn&#39... more The transmural granulomatous inflammation of chronic nature which characterizes the Crohn's disease involves primarily the terminal ileum and colon. However, the upper gastrointestinal tract may also be affected by the same histopathological process, usually co-existent with or following Crohn's disease of the ileocecal region. Such cases can present a formidable diagnostic challenge if the clinical, endoscopic and radiographic findings are not correlated. This article describes and illustrates the spectrum of radiological manifestations of Crohn's disease and its associated complications involving the esophagus, stomach and duodenum.

American Journal of Roentgenology, 1993

Emergency Radiology, 2022

Purpose Ingestion of a toothbrush is an unusual event but may occur either accident or by intent.... more Purpose Ingestion of a toothbrush is an unusual event but may occur either accident or by intent. Radiological examinations play a crucial role in determining the exact location of the object within the gastrointestinal tract and in planning for its removal by endoscopic or surgical intervention. Methods Medical and radiological records of 8 patients who had swallowed the broken heads or entire toothbrush were retrospectively reviewed. This series included 4 men and 4 women, ranging in age from 21 to 57 years (mean: 34 years). Results Radiographs and computed tomography of the abdomen demonstrated the ingested toothbrushes within the stomach in 3, lodged in the duodenum in 1, and entrapped in various parts of the colon in 4 patients. They were removed by laparotomy in 3, laparoscopy in 2, colonoscopy in 2, and upper gastrointestinal endoscopy in 1 patient. There were no perforations or associated complications, and all patients had uneventful recoveries. Conclusions Ingested toothbrushes can be easily identified on radiological studies because of the radiopaque wires holding the nylon bristles. The plastic parts of it, however, are only visible on computed tomography. All cases would require endoscopic or surgical removal of the retained toothbrushes because spontaneous passage per rectum does not occur.

Nature Neuroscience, 2003

Through their distal senses, mammals constantly investigate their environment, and priority in se... more Through their distal senses, mammals constantly investigate their environment, and priority in sensory processing is thought to be given to biologically significant stimuli. The amygdala, a heterogeneous structure in the anteromedial temporal lobe, is a primary neural substrate involved in this processing 1,2. Electrophysiological, lesion and imaging studies have all pointed to an essential role of the amygdala in processing threatening, fearful and highly aversive stimuli 1-6. The view that the human amygdala is particularly responsive to unpleasant (or 'negatively valenced') events has been recently challenged by findings that the amygdala also responds to pleasant (or 'positively valenced') events 7,8. Thus, the precise affective dimensions that characterize amygdala encoding in humans remain unclear. Such indeterminacy of what characterizes amygdala responsiveness is related to the fact that affective space is multidimensional 9,10. Emotion researchers have long appreciated that emotional responses and stimulus evaluations are primarily characterized by two dimensions: intensity and valence 10. Although construed as contributing independently to experience 9,10 , intensity and valence tend to correlate in at least two ways. First, intensity and valence are often asymmetrically correlated between valences. Negative stimuli (for example, a mutilated body) are typically more intense and arousing than positive scenes (a puppy). Second, intensity and valence are often correlated within a valence. An aversive stimulus (fingernails scratching a chalkboard) typically becomes more unpleasant, or acquires greater negative valence, as it becomes more intense (louder). Indeed, this interac

Journal of Vision, 2010

Behavioral and electrophysiological studies in humans suggest that face processing begins in earl... more Behavioral and electrophysiological studies in humans suggest that face processing begins in early development and undergoes a slow maturation during childhood. Little is known about the underlying neural systems or the role of experience in this maturation process. In ...

The American Journal of Digestive Diseases, 1972

The value of propantheline bromide and atropine sulfate in the diagnosis of esophageal varices wh... more The value of propantheline bromide and atropine sulfate in the diagnosis of esophageal varices when conventional esophagography did not show definitive findings was assessed. Twenty patients and 20 control subjects were examined prior to and shortly after these anticholinergic drugs were administered. Visualization of varices was improved remarkably in all 15 patients in whom varices were confirmed on subsequent esophagoscopy. The pharmacoradiologic basis for this method and its significance in the accurate diagnosis of esophageal varices are discussed.

The American Journal of Digestive Diseases, 1974

Two cases of extensive pneumatosis of the colon associated with Crohn's disease are reported.... more Two cases of extensive pneumatosis of the colon associated with Crohn's disease are reported. This unusual complication most likely resulted from intramural dissection of bowel gas due to altered mucosal integrity and increased intraluminal pressure. The clinical and radiographic features of pneumatosis coli have been reviewed with emphasis on differentiation of the underlying gastrointestinal diseases. The similarity of histopathologic findings of Crohn's disease and pneumatosis intestinalis is also mentioned.

Clinical Imaging, 1996

Dysphagia is a delayed symptom of esophageal constriction and often appears after the luminal dia... more Dysphagia is a delayed symptom of esophageal constriction and often appears after the luminal diameter-is reduced to less than 10 mm. Earlier diagnosis of benign or malignant strictures while clinically silent would be desirable; hence we investigated the detectability of occult esophageal lesions with the aid of an ingested barium tablet duringroutine chest radiography. We prospectively examined 300 patients older than 40 years, who were referred for chest films because of indications unrelated to the upper gastrointestinal tract. Each patient was instructed to swallow a l2.5-mm barium tablet with 100mLof waterimmediately prior to the exposure of posteroanterior and lateral chest films. Radiographs of 17patients (5.6%) revealed intraesophageal retention of the tablet, and their prompt evaluation with double-contrast esophagrams confirmed various structural or functional abnormalities in 15 patients. Therefore, the oral administration of a barium tablet during routine chest radiography is a simple efficacious method to assess esophageal patency and detect occult narrowings from structural or functional causes.

The effect of age on motor function of the esophagus was studied manometrically by comparing 49 a... more The effect of age on motor function of the esophagus was studied manometrically by comparing 49 asymptomatic subjects over 60 years of age with 43 similar subjects under 40 years of age. The resting pressures and the responses to deglutition were recorded in the esophagus, lower esophageal sphincter (LES), and the stomach. Significant differences in motility patterns were seen between the two age groups. Although the pressures in the LES were similar in the two groups, the LES response to deglutition was inadequate in 17.8% of swallows in those over 60 years of age and in only 5.9% in those under 40 years. Inadequate LES response was characterized by either a complete absence of response or absence of contractile phase. The amplitude of sphincteric response to deglutition was less in older persons due mainly to a decrease in the amplitude of contraction. In the body of the esophagus the peristaltic contractions were weaker and progressed more slowly in the older group. The incidence of disordered contractions was significantly higher in the older group (25.3% vs 8.2%). Spontaneous gastroesophageal reflux was seen in 9 of the 49 subjects over 60 years of age and in none below 40 years of age. The changes in swallowing patterns indicate a degree of neuromuscular degeneration. They simulate those seen in neuromuscular disorders of esophagus such as diffuse spasm and gastroesophageal reflux. Recognition of the age-related changes is therefore important in interpreting esophageal motility patterns in the elderly. Authors' Summary reflux and chronic obstructive lung disease. In another patient the scan was suggestive of aspiration. The negative results in other 4 cases may indicate that aspiration does not occur every night or may clear before the morning scan is obtained. The value of this simple technique in detection of silent aspiration in patients with asthma, hiatus hernia and neurologic disorders is emphasized.

Journal of Medical Imaging and Radiation Oncology

The aim of this study was to investigate the appearance of acquired rectal diverticula on barium ... more The aim of this study was to investigate the appearance of acquired rectal diverticula on barium enema and computed tomography (CT) and to review the pertinent clinical data about this entity.