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Biomedical subjects

M C Hill

Publications and source records attributed to M C Hill.

At least 19 recordsLinked to original sources
PubMed1996

Comparison of magnetic resonance imaging and transvaginal ultrasonography with hysterosalpingography in the evaluation of women exposed to diethylstilbestrol.

OBJECTIVE: To compare the ability of magnetic resonance imaging (MRI) and transvaginal ultrasound (TV-US) with that of hysterosalpingography (HSG) in detecting uterine abnormalities caused by in utero diethylstilbestrol (DES) exposure. STUDY DESIGN: The study was a prospective MRI and TV-US blind comparison of DES-exposed and nonexposed subjects who had had previous HSG for infertility evaluation. RESULTS: MRI identified uterine constrictions in 60% of patients and T-shaped uteri in 25% of DES-exposed patients with HSG-confirmed abnormalities. TV-US did not identify uterine constrictions or T-shaped uteri in DES-exposed patients. CONCLUSION: HSG must still be considered the preferred method in evaluating DES-related uterine abnormalities. HSG-defined uterine abnormalities associated with in utero DES exposure were variably identified by MRI and not at all by TV-US.

Abnormalities, Drug-Induced↗
PubMed1992

Isolation of telomere junction fragments by anchored polymerase chain reaction.

We describe a simple polymerase chain reaction (PGR)-based method for isolating short stretches of nontelomeric DNA adjacent to arrays of telomere repeat units, in principle applicable to any species for which the telomere repeat sequence is known. Application of this approach to human DNA resulted in the isolation of many candidate telomere junction clones, at least some of which were shown to be derived from telomere-adjacent regions. Most of the isolated clones detect multiple sequences in the human genome which represent one or a few sequence families present at the ends of most or all autosomes and variably truncated before the start of the telomere repeat array. Substantial sequence divergence between different members of these sequence families suggests a low rate of sequence homogenization by telomere exchange processes. The pseudoautosomal telomere junction has also been isolated and contains a shortened version of a recently described family of short interspersed repetitive elements (SINEs), only 14 base pairs (b.p.) from the start of the telomere.

Base Sequence↗
PubMed1991

Peptic ulcer disease: CT evaluation.

The authors retrospectively describe the computed tomographic (CT) findings in 35 patients with peptic ulcer disease. Three of eight patients with gastritis or duodenitis had bowel-wall thickening. Ten of the remaining 27 patients had CT evidence of ulcer perforation (n = 2) or penetration (n = 8), four cases of which were unsuspected clinically. Both patients with acute free perforation had pneumoperitoneum, and one showed free extravasation of orally administered contrast material. The precise site of perforation could not be established in either case with CT. The eight patients with ulcer penetration had CT evidence of bowel-wall thickening (n = 3) and inflammatory changes in adjacent soft tissues and organs (n = 8), including the pancreas (n = 4), liver (n = 1), and lesser omentum (n = 1). Ulcer craters were seen in only two. The CT findings of penetration can mimic other disease processes. CT was not useful in detecting uncomplicated peptic ulcer disease.

Diagnosis, Differential↗
PubMed1991

Sonographic manifestations of medical renal disease.

Ultrasound is usually the first imaging procedure used to evaluate the kidneys in a patient presenting with renal failure. It can allow the physician to make a specific diagnosis of bilateral hydronephrosis as the cause of the renal failure and irreversible end-stage renal disease when bilaterally small echogenic kidneys are seen. In the early stages of medical renal disease, the kidneys may appear normal. As parenchymal diseases progress, changes in the echo architecture of the renal parenchyma take place. These changes, however, are nonspecific and ultrasound-guided biopsy may be necessary to determine the exact histological cause of the patient's renal failure.

Adult↗
PubMed1990

Computed tomography and acute pancreatitis.

Computed tomography (CT) is the best overall imaging modality in the clinical management of acute pancreatitis. It can detect complications such as phlegmonous extension outside the gland, abscess and pseudocyst formation, and hemorrhage. Pancreatic necrosis can be diagnosed with the use of dynamic CT scanning after the rapid bolus injection of iodinated contrast media. The information gathered can be used to guide clinical management and provide anatomic detail for percutaneous aspiration and drainage or surgical intervention when indicated.

Acute Disease↗
PubMed1989

Biliary tract dilatation in chronic pancreatitis: CT and sonographic findings.

The authors retrospectively evaluated 44 patients with chronic pancreatitis to determine (a) what features on computed tomographic and sonographic scans were associated with biliary tract dilatation, (b) how these findings and biliary tract dilatation changed at follow-up, and (c) the correlation between the degree of biliary tract dilatation and the laboratory and histologic findings when available. Twenty-four patients had biliary tract dilatation; of this group 88% had pancreatic calcifications and 75% had a focal mass in the pancreatic head. Sixteen of the 24 patients underwent follow-up studies; in 12 there was no change in the degree of biliary tract dilatation or appearance of the pancreas. The levels of serum alkaline phosphatase and bilirubin were elevated in most of the 24 patients; at follow-up, however, there was no consistent relationship between these values and radiologic findings. Biopsy is recommended for those patients in whom the serum alkaline phosphatase level remains persistently elevated. Four of seven such patients in this study underwent biliary-enteric bypass procedures due to pathologic evidence of cholestasis.

Adult↗
PubMed1988

Adnexal and cul-de-sac abnormalities: transvaginal sonography.

Sixty-seven patients selectively chosen from 354 undergoing conventional transabdominal (TA) sonography for evaluation of a clinically suspected adnexal mass subsequently underwent transvaginal (TV) sonography either because the TA sonograms were technically suboptimal or because it was not possible to characterize with certainty an abnormality identified with TA sonography. TV sonography added diagnostically useful information in 25 of 28 patients with cystic pathologic changes in the adnexa uteri. Eight of 12 patients with tuboovarian abscess and nonspecific adnexal masses visualized with TA sonography had tube-shaped fluid collections characteristic of pyosalpinx identified with TV sonography. TV sonography added diagnostically useful information in all seven patients with diseases of the cul-de-sac (rectouterine fossa) and allowed differentiation of adnexal from primary uterine disease in three patients with TA sonograms on which findings were equivocal. It also expedited the diagnosis of a tubal pregnancy in ten of 14 patients and was useful in the detection of adhesions and perforated intrauterine devices. These results indicate that adjunctive TV sonography can provide important diagnostic information.

Adnexal Diseases↗
PubMed1988

Focal liver lesions.

Despite rapid technologic advances, and the introduction of new, competitive imaging techniques, ultrasound, although a mature modality, remains a versatile and indispensible technology. Ease, access, low cost, and accuracy will assure its central role in the investigation of localized hepatic lesions for the foreseeable future.

Child↗
PubMed1988

Prenatal diagnosis of fetal anomalies using ultrasound and MRI.

In conclusion, it is unlikely that MRI will replace ultrasound as the primary obstetric imaging modality in the near future. Ultrasound has a proven record of accuracy and safety in addition to its easy access and low cost. MRI has promise, however, in providing crucial information in patients with underlying medical or surgical conditions that would ordinarily require ionizing radiation for evaluation. Currently, MRI is helpful in evaluating gross fetal anomalies and disturbances of fetal growth and development when ultrasound is limited by oligohydramnios or maternal obesity. Further experience is required to determine the value of spectroscopy and quantitative relaxation times regarding fetal metabolism and fetal well-being. Technologic improvements and software updates will reduce imaging time and increase spatial resolution, thus rendering MRI more competitive with existing imaging techniques. The ultimate role, however, that MRI will have in the evaluation of the fetus is currently undefined.

Congenital Abnormalities↗
PubMed1987

The superior mesenteric artery fat plane: is obliteration pathognomonic of pancreatic carcinoma?

Obliteration of the fat plane surrounding the superior mesenteric artery has been described as characteristic of pancreatic carcinoma. To determine the specificity of this and other computed tomography findings in the pancreas and peripancreatic region, scans of 86 patients were reviewed without clinical history. Diagnoses included pancreatitis (26 patients); pancreatic adenocarcinoma (14 patients); lymphoma (17 patients); metastatic nonpancreatic carcinoma (14 patients); and normal findings (15 patients). Confluent adenopathy could not be reliably differentiated from a pancreatic mass except when adenopathy separated the common bile duct from the duodenum. Retrocrural adenopathy was unusual with pancreatic carcinoma. The fat plane surrounding the superior mesenteric artery was obliterated with pancreatic carcinoma (36%), nonpancreatic carcinoma (29%), and lymphoma (24%), but not with pancreatitis, although perivascular edema was seen in 19%. Evaluation of the celiac axis was less rewarding. Obliteration of the superior mesenteric artery fat plane is a sign of malignancy, but it is not specific for pancreatic carcinoma. We propose that the superior mesenteric artery origin be considered within a paraaortic space, separate from the anterior pararenal space. This explains its characteristic lack of involvement by pancreatitis.

Adipose Tissue↗
PubMed1987

Second-trimester polyhydramnios: evaluation with US.

The sonograms of 40 patients with second-trimester polyhydramnios were reviewed to determine (a) whether fetal and maternal conditions occur as often during second-trimester polyhydramnios as during third-trimester polyhydramnios, (b) the frequency of persistence of polyhydramnios into the third trimester, and (c) how sonography can help in maternal and fetal management. Second-trimester polyhydramnios often (62%) persisted into the third trimester. The frequencies of maternal (25%) and fetal (12%) conditions were similar to those previously reported for third-trimester polyhydramnios. Fetal anomalies were always identified on the sonogram that initially demonstrated polyhydramnios. Fetal outcome was excellent in the nondiabetic patient with polyhydramnios in whom no fetal abnormalities were detected on sonograms. In polyhydramnios associated with maternal diabetes mellitus, however, the pregnancy was often (71%) complicated by premature labor or macrosomia. In such patients serial sonographic follow-up is indicated.

Amniotic Fluid↗
PubMed1987

The mistaken or indeterminate CT diagnosis of hepatic metastases: the value of sonography.

Small liver cysts may be mistakenly diagnosed as metastatic disease on screening CT of the abdomen in patients with known carcinoma. These cysts can appear solid as a result of volume averaging. On retrospective review of 122 patients with known extrahepatic malignancies and liver lesions on CT, 77 had metastases, three had large cysts, and two had cavernous hemangiomas. The other 40 were found to have single or multiple, small (less than 2-cm), low-density lesions. In 33 patients these were proven to be benign hepatic cysts by sonography, follow-up CT, or clinical course. The initial CT interpretations in these patients had been metastatic disease in seven (21%), benign cysts in five (15%), and indeterminate in 21 (64%). Since the distinction between cysts and metastases has important clinical implications, sonography should be used whenever the true nature of these lesions cannot be determined by CT.

Cysts↗
PubMed1987

Incidentally discovered carcinoma of the pancreas: a potentially indolent lesion.

As examples of unusually indolent behavior of pancreatic carcinoma, two cases are discussed in which the diagnosis was made serendipitously, without symptoms referable to the pancreas. In both cases dystrophic calcification was noted, and pleomorphic giant cells were aspirated from the tumor. In one case, the patient survived 2 yr after diagnosis, dying from unrelated causes. Findings from ultrasound, computed tomography, and magnetic resonance imaging are discussed. Incidental discovery of a pancreatic carcinoma does not preclude a protracted asymptomatic course.

Aged↗
PubMed1986

Dilatation of the common bile duct secondary to a hydronephrotic kidney.

Obstruction of the common bile duct secondary to hydronephrosis is uncommon. We observed common bile duct dilatation secondary to marked right hydronephrosis. Following nephrectomy the common bile duct returned to normal size, confirming the suspicion that the dilatation was due to extrinsic compression.

Adult↗
PubMed1986

Serous carcinoma of the ovary: CT identification of metastatic calcified implants.

The metastasis along peritoneal surfaces of serous cystadenocarcinoma, the most common ovarian malignancy, occurs early and is present in most patients at the time of clinical diagnosis. In many patients, however, computed tomography (CT) is unable to demonstrate peritoneal metastases because of their small size and similarly has been unable to demonstrate metastases in normal sized lymph nodes. Serous cystadenocarcinoma contains histologic calcification in approximately 30% of cases; thus, CT scans were retrospectively reviewed in 15 patients with pathologically proved stage III or IV disease to detect calcified peritoneal metastases. Six patients had calcified peritoneal implants, five of which had perihepatic calcifications. One of the five also had calcified lymphatic metastases, some of which were in normal sized nodes. In three of these five, the examination was otherwise normal. Search for these calcifications should improve the sensitivity of CT in diagnosing metastases from ovarian carcinoma.

Calcinosis↗
PubMed1986

The sonographic evaluation of fetal anomalies in oligohydramnios between 16 and 30 weeks gestation.

The sonograms of all patients with oligohydramnios between 16 and 30 weeks gestation seen over a 4-year period were reviewed to determine (1) whether sonographically detectable fetal anomalies were present, and (2) when these anomalies were present, how this information was used in maternal fetal management. Cases of ruptured membranes and fetal demise were excluded from the study. Sixteen patients with severe oligohydramnios were identified. On postmortem examination, nine had urinary tract anomalies, one had evidence of a chronic intrauterine infection, and four had no anomalies. There were only two neonatal survivors: one had no anomalies while the other had posterior urethral valves. These findings confirm that second trimester oligohydramnios has a poor prognosis and is often associated with anomalies of the urinary tract. Sonography aids in the clinical management of such patients.

Amniotic Fluid↗