National Trends in Lumbar Puncture from 2010 to 2018: A Shift Reversal from the Emergency Department to the Hospital Setting for Radiologists and Advanced Practice Providers.

BACKGROUND AND PURPOSE: Prior research has shown substantial shifts in procedure shares between specialty groups providing lumbar punctures. Our aim was to analyze national trends in lumbar punctures among the Medicare population from 2010 to 2018. MATERIALS AND METHODS: Medicare Part B Physician/Supplier Procedure Summary Master Files from 2010 to 2018 were analyzed for all Current Procedural Terminology, Version 4 codes related to lumbar punctures (62270 and 62272). Lumbar puncture procedure volume and utilization rates were assessed and stratified by place of service and specialty background of the providers. RESULTS: From 2010 to 2018, the overall number of lumbar puncture procedures essentially has not changed (92,579 versus 92,533). Radiologists hold the largest and an increasing procedure share of diagnostic and overall lumbar punctures (overall share, 45.7% in 2010 [n = 42,296] versus 52.3% in 2018 [n = 48,414]). Advanced practice providers have increased their procedure share (3.7% in 2010 [n = 3388] versus 8.4% in 2018 [n = 7785], + 129.8% procedure volume). Emergency medicine physicians and neurologists have a decreasing procedure share (21.8% versus 15.3% and 12.5% versus 8.8%, respectively). The inpatient hospital setting remains the largest place of service for lumbar punctures, recording a 5.3% increase in procedure share. The emergency department lumbar puncture volume has declined, with a 7.4% decrease in the overall procedure share. Similarly, the hospital outpatient department procedure volume has increased (+4%), while the private office volume has decreased (-1.7%). CONCLUSIONS: During the past decade, lumbar puncture procedures among the Medicare population have remained stable, with a shift in procedure volume from the emergency department and private offices to the hospital setting, which has mainly affected radiologists and advanced practice providers.

Pathologic changes of the lateral pterygoid muscle in patients with derangement of the temporomandibular joint disk: objective measures at MR imaging.

BACKGROUND AND PURPOSE: The superior head of the lateral pterygoid muscle (SHLP), which inserts on the anterior disk of the temporomandibular joint (TMJ), can spasm, contracting and exerting forward traction on the disk. This mechanism can lead to anterior displacement. In TMJ dysfunction, it is hypothesized that the SHLP will demonstrate morphologic changes with measurable changes in signal intensity related to atrophy or muscular edema, or both. The goal of this study was to evaluate the lateral pterygoid muscle (LPM) in patients with TMJ dysfunction. MATERIALS AND METHODS: Patients with displacement of the TMJ disk with and without reduction were identified through a review of radiology reports. Absolute measurements of thickness as well as region-of-interest measurements were placed over the 2 heads of the LPM bilaterally on sagittal T1- and T2-weighted images. Statistically significant differences between the superior and inferior heads of the LPM were calculated with use of a 1-tailed Student t test and were correlated with the degree of disk derangement. RESULTS: In patients with disk derangement, significantly increased region-of-interest values on T2- and T1-weighted images were demonstrated within the SHLP. No patients with anatomically normal disks demonstrated a statistically significant difference in region-of-interest values between the superior and inferior heads of the LPMs. CONCLUSION: Correlation between increased region-of-interest values and pathologic alteration of the relationship between the condylar head and disk was identified. In patients with displacement of the anterior disk with and without reduction, region-of-interest values were significantly increased, which indicates abnormal signal intensity involving the superior head of the LPM.

IgA nephropathy: morphologic predictors of progressive renal disease.

IgA nephropathy has a variable course and leads to renal failure in a substantial number of cases. In an attempt to identify prognostic indicators in this disease, we evaluated the clinical and pathologic findings of 20 unselected patients with IgA nephropathy, 13 of whom were followed for 1.5 to 5 years (mean 2.8 years). Biopsy specimens were obtained from all patients and were examined by light and electron microscopy and by immunofluorescence. The activity and severity of the lesions were graded according to a modified classification used by Meadow et al. for the nephropathy associated with Henoch-Schönlein purpura. The results reveal a correlation between the histopathologic grading in the initial biopsy and the clinical outcome: Patients with mild (grade II) or moderate (grade III) lesions had a benign course or showed evidence of active disease without deterioration of renal function, whereas all patients with grade IV or V lesions who were followed for more than one year developed end-stage renal failure. These observations suggest that histologic grading at initial renal biopsy may be a useful prognostic indicator of the clinical outcome of IgA nephropathy.

The role of fat-suppression technique and gadopentetate dimeglumine in magnetic resonance imaging evaluation of intraocular tumors and simulating lesions.

OBJECTIVE: Recent studies have shown that contrast (gadopentetate dimeglumine)-enhanced magnetic resonance imaging is useful in evaluating intraocular tumors and differentiating uveal melanoma from other simulating lesions. The purpose of this study was to study prospectively the role of fat-suppression technique and gadopentetate dimeglumine-enhanced magnetic resonance imaging in the evaluation of intraocular neoplasia. PATIENTS: Forty-three uveal melanomas and 20 other simulating intraocular lesions from 63 patients were prospectively evaluated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with and without fat-suppression technique and on T2-weighted images. RESULTS: Forty-one uveal melanomas (95%) were detected with standard pulse sequences and showed the characteristic hyperintense signal on non-contrast-enhanced T1-weighted images and hypointense signal with respect to the vitreous on T2-weighted images. All 33 uveal melanomas evaluated on non-contrast-enhanced T1-weighted images with fat-suppression technique were detected on non-contrast-enhanced images with fat-suppression technique. The intensity of the signal was statistically associated with the degree of pigmentation of the tumor on T1-weighted images with fat-suppression technique (P = .03). On post-contrast-enhanced T1-weighted images with or without fat-suppression technique, the 43 uveal melanomas showed enhancement. The degree of tumor enhancement was not statistically related to the degree of tumor pigmentation or the location of the tumor. Among the other simulating intraocular lesions, choroidal metastasis, retinoblastoma, choroidal leiomyoma, and medulloepithelioma demonstrated the same features on magnetic resonance imaging studies as uveal melanoma demonstrated on non-contrast-enhanced and post-contrast-enhanced T1-weighted images with or without fat-suppression technique. In our series, choroidal hemangioma, choroidal osteoma, posterior scleritis, retinal hemangioma, and Coats' disease can be differentiated from other amelanotic intraocular tumors by their characteristics on magnetic resonance imaging studies. CONCLUSIONS: We concluded that pre-and post-contrast-enhanced T1-weighted images with fat-suppression technique are most helpful in detecting small intraocular tumors with a thickness of more than 1.8 mm and in evaluating intraocular neoplasms and simulating lesions, particularly when T2-weighted images are not available. Moreover, in juxtapapillary choroidal or retinal tumor, fat-suppression technique may help in the detection of possible optic nerve or orbital extension by improving the conspicuousness of the tumor.

Functionally mature olfactory neurons from two anosmic patients with Kallmann syndrome.

Patients with Kallmann syndrome (KS) exhibit hypogonadotropic hypogonadism and anosmia [Kallmann et al., Am. J. Mental Def., 48 (1944) 203-236] secondary to failure of gonadotropin-releasing hormone (GnRH)-producing neurons to migrate from the olfactory placode to the brain, and to agenesis of the olfactory bulbs. It has been hypothesized that olfactory neurons (ON) from individuals with KS are immature partly on the basis of studies in animals showing that lack of synaptic connection of ON with the olfactory bulb results in expression of immature ON [Schwob et al., J. Neurosci., 12 (1979) 880-883]. To test this assumption, we obtained olfactory tissue samples from two males diagnosed with KS on the basis of medical history and MRI studies. Both patients were anosmic. The functioning of cells isolated from biopsies taken from the upper middle turbinate and septum was studied by measuring changes in intracellular Ca2+ concentration ([Cai]) using dual excitation fluorescence microscopy. Biopsies from both patients yielded cells that morphologically appeared to be ON. Seven of 16 cells that morphologically resembled ON responded with a change in [Cai] upon stimulation with an odorant mixture. These studies show that at least some ON in KS individuals are functionally mature and suggest that complete development of the olfactory bulbs is not required for differentiation of mature human ON.

Noninvasive diagnostic imaging in hemoglobinopathies.

We have provided a global review of the current applications of newer modalities, particularly MR imaging, as applicable to the major manifestations of sickle cell disease, the most common hemoglobinopathy. There is a need for well-designed prospective longitudinal studies utilizing MR imaging to gain further insight into the pathophysiology of this intriguing disease. Additionally, MR imaging, because of lack of ionizing radiation, is ideally suited for long-term sequential studies and may thus provide an objective means for monitoring response to therapy.

Amyloidoma of the nasopharynx: CT and MR findings.

A case of nasopharyngeal amyloidoma with extensive skull base erosion is presented. CT revealed a large, relatively homogeneous, enhancing lesion; MR revealed a signal intensity iso- or slightly hyperintense compared to muscle on T1- and T2-weighted images, with a moderate degree of contrast enhancement. When an erosive mass is encountered at the skull base in a submucosal location in the nasopharynx, and MR demonstrates short T2 relaxation with signal iso- or slightly hyperintense relative to muscle, amyloidoma should be included in the differential diagnosis.

Acute sinusitis mimicking antrochoanal polyp.

Three cases of antral sinusitis that presented in an unusual fashion are reported. In each case, the inflamed, swollen sinus mucosa became redundant and prolapsed into the nasal cavity through a widened sinus ostium, mimicking the findings of an antrochoanal polyp. The cases represent the first report in the radiographic literature of this unusual manifestation of maxillary sinusitis.

Postsurgical conjunctival epithelial cysts.

MR appearance of two patients with large, orbital conjunctival epithelium-lined inclusion cysts are presented. Both were complications of ophthalmic surgical procedures that necessitated conjunctival incision.

Unusual subcutaneous sarcoidosis of the face.

Two unusual cases of sarcoidosis manifesting as subcutaneous masses of the face are reported: in the first, the lesion occurred at the site of an osteotomy for rhinoplasty and was the initial clinical manifestation of sarcoidosis; in the second, the skin lesion was part of a multisystemic disease. The cases were documented with CT. Sarcoidosis should be added to the differential of soft-tissue masses of the face.

Isolated Castleman disease of the neck: MR findings.

Castleman disease in an 11-year-old girl appeared as a neck mass that grew despite antibiotic treatment. MR showed a well-defined solid mass, isointense with muscle on short-repetition-time/short-echo-time images, with a stellate area of central hypointensity on long-repetition-time/long-echo-time images, that did not enhance with gadolinium.

Rare presentations of ordinary lipomas of the head and neck: a review.

The ordinary lipoma is the most common neoplasm of mesenchymal origin. Only 13% of them arise in the head and neck region and most of these occur subcutaneously in the posterior neck. Rarely, they can develop in the anterior neck, infratemporal fossa, and in or around the oral cavity, pharynx, larynx, and parotid gland. Clinically, they can be confused with other benign lesions; however, CT allows a specific diagnosis to be made in virtually all cases. This article reviews the CT appearance and differential diagnoses of lipomas in these rare locations and discusses the rare infiltrating lipoma and the relationship between parotid lipomatosis and sialosis.

Comparison of dynamic contrast-enhanced gradient-echo and spin-echo sequences in MR of head and neck neoplasms.

PURPOSE: To investigate the utility of dynamic contrast-enhanced gradient-echo MR imaging of head and neck lesions and to compare this technique with the commonly used spin-echo contrast-enhanced fat-saturation technique. METHODS: Twenty-two patients with a total of 23 head and neck neoplasms underwent dynamic gradient-echo and spin-echo MR imaging studies. The spin-echo and dynamic gradient-echo images were compared in each case by consensus of three observers for differences in tumor conspicuity and delineation of margins, particularly with regard to invasion of adjacent structures. When possible, pathologic and/or surgical confirmation of tumor extent was obtained. Relative contrast was also calculated to determine objectively the degree of tumor enhancement with respect to background mucosa. RESULTS: The dynamic gradient-echo images showed better or equal delineation of the tumor margins by subjective observation in all but two cases. Temporally different enhancement patterns were noted for lesions, background mucosa, and adjacent reaction and edema. The dynamic gradient-echo technique provided better relative contrast than the spin-echo technique in 17 (77%) of 22 lesions. CONCLUSION: Dynamic gradient-echo MR imaging is superior to conventional contrast-enhanced spin-echo imaging in delineating the margins and extent of tumor. This technique provided observers with added confidence in their interpretations and suffered from fewer technical limitations.

Use trends and geographic variation in neuroimaging: nationwide medicare data for 1993 and 1998.

BACKGROUND AND PURPOSE: Powerful tools, including CT and MR imaging, have revolutionized neuroimaging. These are routinely used, but the extent and variation of use has not been studied. Our purposes were to determine the use rates of MR imaging and CT (of spine, brain, or head and neck), myelography, conventional angiography, and MR angiography in diagnosing neurologic disorders; to study trends in use; and to determine regional variations in use. METHODS: We used the National Part B Medicare Database for 1993 and 1998 to compare rates of use for these procedures in 10 geographic regions. RESULTS: In 1993 and 1998, respectively, 13,897 and 19,431 (39.8% increase) neuroimaging procedures were performed per 100,000 Medicare beneficiaries nationwide. Use of brain or head and neck CT (30.4%) and MR imaging (43.6%), spinal CT (3.5%) and MR imaging (83.0%), myelography (56.6%), and conventional angiography (24.3%) increased in 1998 versus 1993. Increases in MR angiography were not assessed, because this procedure was not reimbursable in 1993. Regional use of brain or head and neck and spinal CT and MR studies varied considerably; ratios of highest and lowest rates were 1.38-1.56. Use of MR angiography, myelography, and conventional angiography varied three- to fourfold. CONCLUSION: Use of MR and CT studies of the brain or head and neck and of the spine increased considerably in the Medicare population between 1993 and 1998. Use of conventional invasive procedures such as myelography and angiography increased strikingly, contrary to the expected decline. Regional use varied substantially.

Low-grade adenocarcinoma of probable endolymphatic sac origin: CT and MR appearance.

The CT and MR appearance of a case of low-grade adenocarcinoma of probable endolymphatic sac origin is presented. The tumor destroyed a large part of the posterior temporal bone and showed prominent extension into the posterior cranial fossa.

Sinonasal imaging. Anatomy and pathology.

This article provides a clear understanding of the pathophysiology of sinonasal inflammatory diseases and the rationale behind endoscopic surgery. Normal anatomy and pertinent anatomic variants that should be included in the radiology report are described. The relative role of CT and MR imaging in evaluation of inflammatory and neoplastic lesions is emphasized.

Magnetic resonance imaging of diffuse bone marrow disease.

MR is a highly sensitive alternative to plain films, CT, and radionuclide studies for the imaging of normal and abnormal marrow and can characterize differences between fatty, fibrotic, cellular, hypercellular, and hemosiderotic marrow. MR is helpful in depicting the extent of disease and has been a useful method to follow the clinical course of many disorders. It has been found to be particularly useful in explaining the unrepresentative biopsy, as the distribution of many diseases is frequently heterogeneous as exemplified by the mixed fatty and cellular patterns of aplastic anemia, myeloma, lymphoma, and skeletal metastases. Patterns of cellular and fatty marrow in the epiphysis and apophysis after marrow reconversion were not completely understood prior to the introduction of MR scanning. Because it has the advantage of imaging the entire bone marrow compartment (unlike the situation with biopsy on aspiration), MR allows a better understanding of the distribution of skeletal disease.

Enhanced resolution of pituitary fossa by three-dimensional fat-suppressed gradient-echo magnetic resonance: before and after gadolinium enhancement.

In imaging small anatomical parts such as the pituitary fossa, thin sections enhance the spatial resolution. Gradient recalled images (GRASS) using three-dimensional volume data produce ultrathin contiguous sections with a high signal-to-noise ratio. In this study, conventional spin-echo magnetic resonance images (MRIs) of the pituitary fossa were compared to three-dimensional gradient recalled MRI in 5 volunteers and 10 patients suspected of having pituitary gland abnormalities. Utility of fat suppression was also assessed, along with gadolinium enhancement. Conventional spin-echo and three-dimensional spoiled GRASS images, three-dimensional spoiled GRASS images without and with fat suppression (Group II), and three-dimensional spoiled GRASS images with fat suppression before and after gadolinium enhancement were compared. Three-dimensional spoiled GRASS images provided better delineation of the pituitary fossa structures. There was differential enhancement between the normal gland and pituitary tumors. The fat suppression technique following gadolinium administration helped separate the high signal of tumor from the high signal of the clivus marrow. In conclusion, T1-weighted three dimensional gradient-echo images with fat suppression following gadolinium enhancement appear promising in evaluation.

Aqueous solubility and dissolution rate does not adequately predict in vivo performance: a probe utilizing some N-acyloxymethyl phenytoin prodrugs.

Some physicochemical properties of N-acyloxyalkyl prodrugs of phenytoin were reported previously.(1,2) It was shown that despite their lower aqueous solubilities relative to phenytoin, these lower-melting prodrugs with apparently disrupted crystalline structures gave either comparable or enhanced in vitro solubility and dissolution rate in simulated intestinal media made up of bile salts and lecithin (SIBLM).(2) The current objective was to compare the in vivo behavior of two of these prodrugs to phenytoin in dogs and attempt to correlate the in vitro behavior to their in vivo behavior. The oral bioavailability of phenytoin after administration of phenytoin (1) and the selected prodrugs, 3-pentanoyloxymethyl 5, 5-diphenylhydantoin (2) and 3-octanoyloxymethyl 5, 5-diphenylhydantoin (3), in fed and fasted beagle dogs were compared to intravenously administered phenytoin. Phenytoin and its prodrugs showed improvement in fed-state phenytoin bioavailability relative to the fasted state indicating that food enhanced the delivery of phenytoin from phenytoin and its prodrugs. The increased bioavailability in the fed state may be due to stimulation of bile release by food and, for the prodrugs, possible catalysis of their dissolution by lipases.(3) In both, fasted and fed states, prodrugs 2 and 3 gave higher AUC values of phenytoin than the parent compound. The enhanced bioavailability of phenytoin after oral administration were more obvious in fed dogs. Although enhanced, AUC values of phenytoin from the prodrugs relative to phenytoin were not statistically different (at 95% confidence level) in fasted state, but were different in fed state. Although the aqueous solubilities and dissolution of both prodrugs were lower than phenytoin, dissolution of 2 and 3 was equivalent and greater, respectively, relative to phenytoin in SIBLM. As expected, the in vivo behavior correlated better with the in vitro SIBLM dissolution behavior. These results indicate that aqueous solubility per se does not adequately predict in vivo behavior.

Controlled and complete release of a model poorly water-soluble drug, prednisolone, from hydroxypropyl methylcellulose matrix tablets using (SBE)(7m)-beta-cyclodextrin as a solubilizing agent.

Sustained-release formulations such as hydroxypropyl methylcellulose (HPMC)-based hydrophilic matrix tablets of poorly water-soluble drugs often result in incomplete release because of the poor solubility and dissolution rate of the drug in the hydrophilic matrix. Sulfobutylether-beta-cyclodextrins ((SBE)(7M)-beta-CDs) have been known to improve the solubility of such drugs by forming inclusion complexes. The present paper deals with the modification of drug release from an HPMC-based matrix tablet of a sparingly water-soluble drug, prednisolone (PDL), using (SBE)(7M)-beta-CD as a solubilizing agent. Tablets were prepared by direct compression of a physically mixed PDL, (SBE)(7M)-beta-CD, and polymer. On exposure to water, an in situ PDL:(SBE)(7M)-beta-CD complex was formed in the gel layer, and enhanced drug release relative to a control formulation was observed (lactose used as the excipient instead of (SBE)(7M)-beta-CD ). Other possible changes due to the incorporation of (SBE)(7M)-beta-CD in the formulation were also probed. Incorporation of (SBE)(7M)-beta-CD lead to a higher water uptake relative to the control (lactose) formulation. For a fixed total tablet weight, polymer type, and loading, the drug release rate appeared to depend on the molar ratio of (SBE)(7M)-beta-CD to PDL and not the absolute amount of (SBE)(7M)-beta-CD present in the matrix tablet. This work shows that incorporation of (SBE)(7M)-beta-CD into the matrix tablets could be considered in designing a sustained-release tablet of poorly water-soluble drugs.