NLS-DIAGNOSTICS OF PROSTATE DISEASES
V.A. Toropova, S.N. Petrenko
An ever growing number of physicians enjoy an opportunity of screening NLS diacrisis of prostate gland and urinary bladder. This article attempts ti consider some particular of morphological changes occurring in a prostate affected by pathology, based on the results of NLS-investigations.
In the West prostate cancer makes 20% of the total cancer diseases and ranks second to lung tumors as a depth cause.
According to some autopsy finding with a histological investigation of the prostate, 12-47% of men aged over 50 appeared to have cancerous nidi. Clinically, cancer is diagnosed moer rarely because a high percentage of that number corresponds to "minor forms" of cancer that have low invasiveness, so the patients suffering from it die of another king of pathology.
The enhance the quality of prostate disease diagnostics it is important to comprehend to specifics of topographic and zonal anatomy of particular organ
The prostate gland is located in a small pelvis between the bladder and anterior abdominal wall, anterior rectum wall and secondary urgenital diaphragm. The gland has a chestnut shape and tightly envelops the bladder cervix and prostatic urethra. The gland base is tightly connected with the bladder into a coherent mass. Its anterior surface is directed to the symphisis, and the posterior one - to the rectum ampulla. The posterior surface of the gland has an expressed sulcus, which allow to conventionally subdivide the gland into the left and right lobes. Beside, there is a protruding middle cone-shaped lobe confined anteriorly by the prostatic urethra and by the spermatic duets posteriorly.
According to zonal anatomy theory usually 4 glandular zones are distinguished in the prostate. The correct interpretation of NLS data largely depends on the knowledge of their topical pattern. 20% of the glandular tissue correspond to the central zone (CZ). The peripheral zone (PZ) occupies 75%. The intermediate (transitory) zones (TZ) make up 5% of the total amount of the glandular tissue.
Peruretharal glands (PUG) take a relatively small amount if the tissue however exactly this area of the gland is very important for explaining changes at a benign hyperplasia.
Apart from the glandular area, 4 fibro muscular zones can be disconnected:
1) Anterior fibro muscular stoma (AFS).
2) Unstriated muscular fibers of the urethra (UMFU)
3) Preprostatic sphineter (PPS), which is an extension of the musculature of the inferior part of the urecter and prevents inverse emission of semifliud
4) Postprostatic sphincter (PPS), which is responsible for retain urine in the bladder and blocks incontinent micturition
The gland can be conventionally subdivided into 2 parts:
-external part consisting of CZ, PZ, TZ and
-internal part comprising AFS, PPS and PoPS.
According to NLS-investigation, the external part looks like a structure of normal chromogogenic density( 2-4 points on Flandler's scale), and internal one is hypochromogenic (1-2 points). The two parts are divided fibro muscular layer, the so called surgical capsule, along which an incise made during surgical intervention, and calcium salts deposit (calcium imitation of the gland).in the NLS investigation those formations can be seen as fairly hypochromogenic structures (3-4 points) od different size.
The analysis of the prostatic gland image on th NLS virtual moc mae according to the fallowing quantity characteristics:
1 size: front to back - 2-2.5 cm, across - 3-4.5 cm, from top to bottom - 2.5-4 cm;
2 volume: up to 29 cm;
3 symmetry. The urethra is the reference point.
If any pathological changes are detected in the NLS-graph it is recognized to:
-specify their extra location
- perform histograph of the pathological area and area of the tumor with a normal structure.
It will be helpful for the case fallow-ups. At the begging hyperplasia allows to detect the direction of the principal germination. In case of hypertrophic transitory zones the gland proliferates inwards. Though darkened lateral zones are formed ( 405 points on Flandler's scale), the nodes can still always visualized. The trans-rectal NLS offers the most detailed and automatic information.
Enlarged lateral lobes squeeze PZ and CZ causing their atrophy. With proliferation of the paraurethral zones a massive fibro muscular PPS layer restricts of their hyporplasis, so with this kind of pathology the gland proliferates along the urethra forming a middle darkened zones pushing back the bladder wall. Visrtual scanning makes this pathology clearly visible in longitudinal sections. At the beginning of the proliferation a relationship between the internal and external glandular parts id disturbed. Apart from some distinctions in the zone of principal proliferation, the clinical sings will be different as wee. In the case where a globe-shaped gland is formed (TZ prolification) the gland is chiefly hyperchromogenic and the dysuric manifestations are minimal while with a "middle zone" formed the gland is slightly darkened and dysuria appears to be frank. Sphincter decompensation leads to the development of urinary incontinence and dilation of the upper urinary track fallowed by the atrophy of the cortical layer of kidneys, which gradually adds to frequent urination, nycturia, reduced pressure of the urine or slowed-down urination occurring in the initial phase of the disease.
In case of squeezed cervix of the bladder an NLS-graph allows to visualized sings of an infravesical obstruction, that causes some morphological and functional changes in the lower and upper urinary tracks. Specifically. In the initial phases of benign hyperplasia a darkened wall in the bladder can be observed. Dark patches result from compensatory hyprthropy of the detrusor.
These 3 phases of benign hyperplasia of the prostate can be distinguished depending on the intensity of the changes:
1. Hyperchromogenic density of the gland with no residual urine;
2. Residual urine present;
3. All of the above-mentioned plus dilatation of the upper urinary tract with the cortical layer of kidneys involved in the process.
Diagnosis of the acute prostatitis is made in the basis of histograms (similarity to the reference standard process "prostatitis" D<0.425). diagnostication should be done in combination with dactylar rectal examination ( painfulness during papation) with clinic lab data taken into account.
In this case oc abscessed lesion a still higher hyprchromous area (6 points) is visible against the general dak patch ( 4-5 point according to Flandler's scale). Areas of frank blackening correspond to necrotic changes. Which an abscess in progress one can notice a reduced infiltration of the tissue around the cavity with the dark patch gradually lighter in the course of dynamic observation ( up to 3-4 pints). With adequate therapy employed the postinflamentory cyst may fall into regression.
As can been seen from NLS-investigation , chronic prostatits dose not give a common characteristic picture, however the morphological processes in different phases of the disease are reflected in histograms. With a long-lasting diseases the chromogenetic density tends to rise due to a postinflammatory substitutions mode destructing of the fibrous component starts to predominate.
With an oncological pathology analysis of the gland picture helps locate the process in different projections and assess the extent of prevalence and involvement of adjacent organs. The minimum size of tumor determinate by means of NLS-investigation is about 8-10 mm. 805 of the timorous nodes are represented by markedly hyperchromogenic structures (6 points on Flandler's scale)
Analysis of histogram of the nidid helps differentiate an oncoprocess. The method's sensitivity becomes higher with both 'elimination' and NLS-anaysis'modes in use. Peripheral zone shape first place as far as cancer incidence rate s concerned. Their shape make 70-80% of cases. In transitory zones (TZ) are affected in 10-20% and CZ in less than 5% of cases. In transitory zones a timorous nidus should be looked for within 3-4mm from the capsule. In case of any oncological alertness the symmetry in the lobe affection is assessed w.r.t the sagittal axis and intensity of the black patch (4-5 point on Flandler's scale) in the adjacent organs, especially seminal vesicles and bladder because in 25% of cases metasitzing occurs through the gland apex and seminiferous tracks. Considering the fact that cancer often develops with some diffuse changes occurring on the background, foe example, with chronic prostatic or adenomatosis, it is not always possible to visualize newly formed cancerous areas. In such cases the result if PSA level definition and digital rectal examination should be considered. The PSA level is defined considering the patient's age and gland volume.
1NLS-method allows to diagnose most prostate disease and being a screening diagnostic method, it should be supplemented by biopsy, should any pathiological changes be detected.
2. the final diagnostic should be made on the basis the clinical lad data and the result of digital rectal examination in combination with biopsy only.